Biowissenschaften
Refine
Year of publication
Document Type
- Article (130)
Language
- English (130)
Has Fulltext
- yes (130)
Is part of the Bibliography
- no (130)
Keywords
- Haloferax volcanii (6)
- aging (5)
- Biogeography (4)
- Podospora anserina (4)
- heat stress (4)
- Acinetobacter baumannii (3)
- Archaea (3)
- Biodiversity (3)
- Biohydrogen (3)
- genomics (3)
- hippocampus (3)
- mitochondria (3)
- quality control (3)
- ABC transporter (2)
- AJAP1 (2)
- Antarctica (2)
- Arabidopsis (2)
- Coenzyme A (2)
- Cortex (2)
- Ecological modelling (2)
- Formate dehydrogenase (2)
- Hydrogen production (2)
- Hydrogenase (2)
- Invasive species (2)
- Land cover (2)
- Non-coding RNA (2)
- Operons (2)
- Pantothenate (2)
- Saccharomyces (2)
- Solanum lycopersicum (2)
- amyloid precursor protein (2)
- archaea (2)
- autophagy (2)
- connectedness to nature (2)
- connection to nature (2)
- deletion mutant (2)
- desiccation (2)
- mannitol (2)
- microbiome (2)
- microglia (2)
- peptide-loading complex (2)
- phylogeny (2)
- presynaptic active zone (2)
- regulation (2)
- ribosome (2)
- thermotolerance (2)
- 1-octanol (1)
- 2cpsdummy′-O-ribose-methylation (1)
- 3D printed stamp (1)
- A. thaliana (1)
- ABE fermentation (1)
- ADCD (1)
- ADP (1)
- AMPK (1)
- ATP (1)
- ATP synthase (1)
- ATPase (1)
- Acetobacterium woodii (1)
- Acetogenic bacteria (1)
- Acetyl-CoA (1)
- Acetylating acetaldehyde dehydrogenase (1)
- Adherence junctions (1)
- Adhesion (1)
- Aedes aegypti (1)
- Aedes albopictus (1)
- Agent-based modeling (1)
- Agroecology (1)
- Akaike information criterion (1)
- Anamorphic fungi (1)
- Angiogenesis (1)
- Animal physiology (1)
- Anisakid nematodes (1)
- Antisense RNA (1)
- Apis mellifera (1)
- Applied microbiology (1)
- Aquatic invertebrates (1)
- Arabidopsis thaliana (1)
- Arabidopsis thaliana metabolism (1)
- Ascomycota (1)
- Automation (1)
- BMP signaling (1)
- Basidiomycota (1)
- Bathydraconinae (1)
- Bayesian information criterion (1)
- Behavioural ecology (1)
- Behavioural methods (1)
- Benin (1)
- Benthos (1)
- Biochemistry (1)
- Biofuel (1)
- Biogeography of disease (1)
- Biological invasion (1)
- Biomarker (1)
- Biomonitoring (1)
- Bioreactor (1)
- Biosynthesis (1)
- Birds of prey (1)
- Blastocysts (1)
- Brassicales (1)
- C-value (1)
- CDC-42 (1)
- CLP protease (1)
- CLPXP protease (1)
- CO2 reduction (1)
- Canis lupus (1)
- Caprylic acid (1)
- Carbon capture (1)
- Carboxylic acid reductase (1)
- Castor bean tick (1)
- Cell differentiation (1)
- Cell migration (1)
- Cercospora (1)
- Chaenodraco wilsoni (1)
- Champsocephalus gunnari (1)
- Channichthyidae (1)
- Chemical communication (1)
- Chemical contamination (1)
- Chorion (1)
- Chorismate mutase-prephenate dehydratase (1)
- Chromosomes and gene expression (1)
- Chrysops (1)
- Climate (1)
- Climate change (1)
- Climatic habitat suitability (1)
- Cochlea (1)
- Communication center (1)
- Compartmentalization (1)
- Contact microradiography (1)
- Contracaecum (1)
- Core marking (1)
- Cre-lox system (1)
- Crustacea (1)
- Cytoskeleton (1)
- DNA transporter (1)
- Dark fermentation (1)
- Deep sea (1)
- Dehydration (medicine) (1)
- Developmental biology (1)
- Developmental biology and stem cells (1)
- Diptera (1)
- Diversity (1)
- Earthworms (1)
- Ecological niche modeling (1)
- Ecology (1)
- Ecophysiology (1)
- Ecotoxicological status class (1)
- Ectoparasites (1)
- Eltonian noise hypothesis (1)
- Embryos (1)
- Endoplasmic reticulum (1)
- Endothelial cells (1)
- Envelope (1)
- Environmental sciences (1)
- Evaluation matrix (1)
- Evolution (1)
- Extinction (1)
- F1Fo-ATP-synthase (1)
- FAD (1)
- Fabaceae (1)
- Fatty acid synthase (1)
- Fatty alcohol (1)
- Feather mites (1)
- Feeding behavior (1)
- Fluorescent proteins (1)
- Fungi (1)
- Fusarium (1)
- GC content (1)
- GLUT2 (1)
- GLUT3 (1)
- Gammarus fossarum (1)
- Gammarus roeselii (1)
- Gene prediction (1)
- Generation time (1)
- Genome annotation (1)
- Genotyping (1)
- Gerlachea australis (1)
- Global (1)
- Global warming (1)
- Golgi (1)
- Great philippine eagle (1)
- Gymnodraco acuticeps (1)
- HER (1)
- HSBP (1)
- HSF (1)
- Haematopota (1)
- High content imaging (1)
- Hispaniola (1)
- Hominins (1)
- Host specificity (1)
- Human impact (1)
- Hydrogen storage (1)
- Hydrogen-dependent CO2 reductase (1)
- Hydrogen-dependent CO2 reductase (HDCR) (1)
- Hydromorphology (1)
- Hydroxymandelate synthase (1)
- Hypothermia (1)
- INS (1)
- Image processing (1)
- In vitro assays (1)
- Indoles (1)
- Insects (1)
- Insularity (1)
- International survey (1)
- Intraspecific divergence (1)
- Ixodes ricinus (1)
- Klebsiella oxytoca (1)
- LTP (1)
- LUCA (1)
- Lactation (1)
- Leaderless transcript (1)
- Leaf clearing (1)
- Leguminosae (1)
- Lepidoptera (1)
- Life-history evolution (1)
- Light sheet-based fluorescence microscopy (1)
- Local adaptation (1)
- Localized defecation (1)
- Long-term live imaging (1)
- MHC (1)
- Macropus (1)
- Malpighiales (1)
- Mammary gland (1)
- Mandelic acid (1)
- Marine biology (1)
- Massive Analysis of cDNA Ends (MACE) (1)
- Mathematical models (1)
- Maxent (1)
- Metabolic engineering (1)
- Metabolomics (1)
- Micro CT (1)
- Microplastics (1)
- Microthlaspi erraticum (1)
- Microtubules (1)
- Midbrain (1)
- Mindanao hawk-eagle (1)
- Mitochondria (1)
- Model (1)
- Model complexity (1)
- Molecular biology (1)
- Molecular phylogeny (1)
- Mollusca (1)
- Mortality (1)
- Multidimensional imaging (1)
- Neopagetopsis ionah (1)
- Network analysis (1)
- Neurophysiology (1)
- Niche (1)
- Nisaetus pinskeri (1)
- Northern blot (1)
- Notch signaling (1)
- Nothopassalora (1)
- O-CAS assay (1)
- Octanoic acid (1)
- Optimization (1)
- Oxidative stress (1)
- P2Y13 receptor (1)
- PAR complex (1)
- PSII core phosphorylation (1)
- Pagetopsis macropterus (1)
- Palaeontology (1)
- Parachaenichthys charcoti (1)
- Parasites (1)
- Parasites of endangered species (1)
- Passalora (1)
- Pelagic (1)
- Petri net (1)
- Phylogenetics (1)
- PilF (1)
- Pithecophaga jefferyi (1)
- Planetary boundaries (1)
- Population density (1)
- Population dynamics (1)
- Potamopyrgus antipodarum (1)
- Proline (1)
- Promoter (1)
- Protein domains (1)
- Pseudocercospora (1)
- Pseudochaenichthys georgianus (1)
- Pseudoterranova (1)
- Pterolichoidea (1)
- Quantitative imaging (1)
- RMP1 (1)
- RNA polymerase (1)
- RNA sequencing (1)
- RNA-seq (1)
- Racovitzia glacialis (1)
- Rapid evolution (1)
- Rearing temperature (1)
- Reproducibility (1)
- Reproduction (1)
- Retrotransposon (1)
- Rnf complex (1)
- Robert Koch Institute (1)
- SNF1 (1)
- SPAdes (1)
- Saccharomyces cerevisiae (1)
- Scale-up (1)
- Schizokinen (1)
- Sea water (1)
- Shallow water (1)
- Shores (1)
- Short-chain fatty acids (1)
- Shrew-1 (1)
- Signal inhibition (1)
- Small nucleolar RNA (1)
- Social behaviour (1)
- Solanum lycopersicum L. (1)
- Solenidae (1)
- Species distribution modelling (1)
- Species richness (1)
- Spectral clustering algorithm (1)
- Spheroids (1)
- Splice variants (1)
- Standardization (1)
- Stem cells (1)
- Surface range (1)
- Swimming (1)
- Tabanidae (1)
- Tabanus (1)
- Thermal pollution (1)
- Thermoanaerobacter kivui (1)
- Thermophiles (1)
- Threatened species (1)
- Three-dimensional cell culture (1)
- Tick-borne diseases (1)
- Tiger mosquito (1)
- Tissue integrity (1)
- Tools and resources (1)
- Tortoise beetles (1)
- Toxicity (1)
- Trans-2-enoyl-CoA reductase (1)
- Transcriptome (1)
- Transcriptome analysis (1)
- Transgenesis (1)
- Transposable elements (1)
- Tribolium castaneum (1)
- Tuber aestivum (1)
- Tumor suppressor protein (1)
- Tyrosine prototrophy (1)
- UV-stress (1)
- UV/V cones (1)
- University students (1)
- Urban ecology (1)
- Urgent actions (1)
- Vector borne diseases (1)
- Vector mosquito (1)
- Vector-host-interaction (1)
- Vectorpathogen-host (1)
- Vein density (1)
- Vein networks (1)
- Weather conditions (1)
- West Africa (1)
- Whales (1)
- Wnt (1)
- Wood–Ljungdahl pathway (1)
- Yeast (1)
- Yellow fever mosquito (1)
- Zebrafish (1)
- aIF (1)
- acetogenesis (1)
- acetogenic bacteria (1)
- acetyl-CoA (1)
- acoustic startle reflex (1)
- acquisition strategy (1)
- activity budgetx (1)
- adaptive immunity (1)
- adaptive transgenerational plasticity (1)
- adult neurogenesis (1)
- alternative splicing (1)
- alzheimer’s disease (1)
- amplicon sequencing (1)
- animal behaviour (1)
- animal migration (1)
- annual plants (1)
- anti-oxidants (1)
- antigen presentation (1)
- antigen processing (1)
- aposematism (1)
- asexual fungi (1)
- asymmetry (1)
- auditory cortex (1)
- auditory processing (1)
- background noise (1)
- bacterial communities (1)
- behavioural ecology (1)
- betaine/choline/carnitine transporter (1)
- biodiversity loss (1)
- biofilm (1)
- biomod (1)
- biosynthetic gene clusters (1)
- biotrophic parasites (1)
- bromeliads (1)
- brood (1)
- carnitine metabolism (1)
- carnivores (1)
- carotenoids (1)
- chlorophyta (1)
- chloroplast phosphorylation network (1)
- chromosome number (1)
- climate (1)
- climate change-induced range shifts (1)
- climate-change ecology (1)
- clostridia (1)
- coherence (1)
- cold tolerance (1)
- coloration (1)
- common transition pairs (1)
- compaction (1)
- comparative genomics (1)
- compass orientation (1)
- compatible solutes (1)
- computed tomography (1)
- connectedness to nature scale (1)
- connectedness to nature scale (CNS) (1)
- conservation (1)
- conservation biology (1)
- copyright (1)
- cortical flow (1)
- costs (1)
- coupling (1)
- cryptochrome (1)
- dRNA-Seq (1)
- database (1)
- dataset (1)
- dentate gyrus (1)
- development (1)
- diatoms (1)
- drug screening system (1)
- ectrogella (1)
- education for sustainable development (ESD) (1)
- electron bifurcation (1)
- energy conservation (1)
- energy metabolism (1)
- ensemble forecasting consensus model (1)
- environmental behavior (1)
- environmental factors (1)
- environmental knowledge (1)
- enzyme activity (1)
- eukaryotic system (1)
- evolution (1)
- flow cytometry (1)
- forest tree (1)
- formate dehydrogenase (1)
- freeze avoidance (1)
- frontal cortex (1)
- functional coupling (1)
- fungi (1)
- gap duration (1)
- gap-prepulse inhibition (1)
- gel retardation (1)
- gene conversion (1)
- gene expression (1)
- gene flow (1)
- gene loss (1)
- genomic base composition (1)
- geographic distributions (1)
- giraffe (1)
- glucose transport inhibitor (1)
- grisel syndrome (1)
- hardwood (1)
- heat shock protein (1)
- heat stress transcription factor (1)
- heterozygous cells (1)
- homeostasis (1)
- human host adaptation (1)
- human pathogen (1)
- hxt0 yeast strain (1)
- hybrid assembly (1)
- hybrid enrichment (1)
- hybridization (1)
- hydrogen production (1)
- hydrogen storage (1)
- hydrogenase (1)
- hydroxamate (1)
- illustrated inclusion of nature in self scale (IINS) (1)
- imaging protocol (1)
- inclination compass (1)
- inclusion of nature in self scale (INS) (1)
- inclusion of technology affinity in self-scale (ITAS) (1)
- incomplete lineage sorting (1)
- insect (1)
- insecticides (1)
- intellectual property (1)
- inter- seasonal predictability (1)
- interaction networks (1)
- intracellular protein localization (1)
- invariant transition pairs (1)
- iron starvation (1)
- kangaroo (1)
- kinase protein interaction (1)
- large carnivores (1)
- larva (1)
- larvae (1)
- latitudinal gradient in species richness (1)
- learning difficulties (1)
- lichen secondary metabolites (1)
- ligand binding (1)
- light-stress (1)
- lipid peroxidation (1)
- local-field potentials (1)
- mPTP (1)
- magnesium transporters (1)
- magnetic resonance imaging (1)
- magnetoreception (1)
- maladaptation (1)
- mating type (1)
- melanization (1)
- membrane proteins (1)
- metabolic pathway (1)
- metagenome assembly (1)
- miracula (1)
- mitophagy (1)
- model verification (1)
- molecular phylogenetic analysis (1)
- molecular tug-of-war (1)
- morphogenesis (1)
- motif search (1)
- multi-generation experiment (1)
- multilocus genotype (1)
- museum collections (1)
- mutational spectrum bias (1)
- n-Butanol (1)
- n-butanol (1)
- natural competence (1)
- nature relatedness scale (NR) (1)
- network reduction (1)
- network state changes (1)
- neurodegeneration (1)
- neuronal network (1)
- nicotinic acetylcholine receptors (1)
- non-ribosomal peptide synthetases (1)
- nontraumatic atlantoaxial rotatory subluxation (1)
- oakmoss (1)
- off-target reads (1)
- one new species (1)
- oomycetes (1)
- open access (1)
- organellar ploidy levels (1)
- ortholog search (1)
- oscillations (1)
- osmotic stress (1)
- parasites (1)
- peptide editing (1)
- peroxisomes (1)
- phenotypic analysis (1)
- phenotyping (1)
- phosphate starvation (1)
- photocycle (1)
- photosynthesis (1)
- photosystem II assembly and repair (1)
- phylogenetic conflict (1)
- phylogenetic profile (1)
- phylogenetic signal (1)
- phylogenomics (1)
- pictorial scale (1)
- piracy (1)
- planar polarity (1)
- plant-microbe interactions (1)
- plastic response (1)
- plastome (1)
- ploidy (1)
- polyketide synthases (1)
- polyploidy (1)
- polytomy (1)
- population growth (1)
- posttranslational regulation of photosynthesis (1)
- pre-mRNA (1)
- predator pressure (1)
- prepulse inhibition (1)
- progenitor cell (1)
- protected areas (1)
- protoplast fusion (1)
- pseudouridylation (1)
- publishing (1)
- pupil diameter (1)
- pupillometry (1)
- qH2 (1)
- rRNA (1)
- radical pair model (1)
- radicals (1)
- razor clams (1)
- recolonization (1)
- relational values (1)
- respiratory chain (1)
- ribosomal proteins (1)
- ribosome biogenesis (1)
- root allocation strategy (1)
- root functional traits (1)
- royal jelly (1)
- sRNA (1)
- sRNA regulon (1)
- scale validation (1)
- sci-hub (1)
- seedling (1)
- selection gradients (1)
- senescence (1)
- sensory coding (1)
- sequence evolution (1)
- sequencing error (1)
- siderophore (1)
- signaling (1)
- single item measurement (1)
- singlet oxygen (1)
- sleep (1)
- small protein (1)
- small regulatory RNA (1)
- snoRNA (1)
- soil VOCs (1)
- soil degradation (1)
- soil fungal communities (1)
- special needs education (1)
- speciation (1)
- species distribution modeling (1)
- species richness (1)
- structure activity relationship (1)
- substrate-binding site (1)
- sustainable development goals (SDGs) (1)
- swarming (1)
- symbiosis (1)
- synapse (1)
- systems biology (1)
- tapasin (1)
- taxon sampling (1)
- technology acceptance (1)
- technology affinity (1)
- technology in education (1)
- terpene synthases (1)
- thermophile (1)
- thylakoid kinases (1)
- tinnitus (1)
- torticollis (1)
- transcription (1)
- transcription factor (1)
- transcriptome (1)
- transcriptomics (1)
- transient regulation (1)
- transition invariant (1)
- translation initiation (1)
- tree moss (1)
- trehalose (1)
- tropical fungi (1)
- twilight zone (1)
- two factor model of environmental values model (1)
- type IV pili (1)
- unselected segregation (1)
- video observation (1)
- volatile organic compounds (1)
- wax layer (1)
- winter survival (1)
- zinc finger protein (1)
- zoo biology (1)
- µ-protein (1)
Institute
- Biowissenschaften (102)
- Institut für Ökologie, Evolution und Diversität (32)
- Senckenbergische Naturforschende Gesellschaft (24)
- Exzellenzcluster Makromolekulare Komplexe (20)
- Biodiversität und Klima Forschungszentrum (BiK-F) (18)
- Biochemie und Chemie (5)
- Medizin (5)
- Center for Membrane Proteomics (CMP) (4)
- Informatik (4)
- Sonderforschungsbereiche / Forschungskollegs (2)
Diurnal and nocturnal behaviour of cheetahs (Acinonyx jubatus) and lions (Panthera leo) in zoos
(2022)
Mammals are constantly exposed to exogenous and endogenous influences that affect their behaviour and daily activity. Light and temperature, as well as anthropogenic factors such as husbandry routines, visitors, and feeding schedules are potential influences on animals in zoological gardens. In order to investigate the effects of some of these factors on animal behaviour, observational studies based on the analyses of activity budgets can be used. In this study, the daily and nightly activity budgets of six lions (Panthera leo) and five cheetahs (Acinonyx jubatus) from four EAZA institutions were investigated. Focused on the influencing factor light and feeding, we analysed these activity budgets descriptively. Behaviour was recorded and analysed during the winter months over an observation period of 14 days and 14 nights using infrared-sensitive cameras. Our results show that lions and cheetahs exhibit activity peaks at crepuscular and feeding times, regardless of husbandry. Thus, lions in captivity shift nocturnal behaviour familiar from the wild to crepuscular and diurnal times. In cheetahs, in contrast, captive and wild individuals show similar 24 h behavioural rhythms. The resting behaviour of both species is more pronounced at night, with cheetahs having a shorter overall sleep duration than lions. This study describes the results of the examined animals and is not predictive. Nevertheless, the results of this study make an important contribution to gaining knowledge about possible factors influencing the behaviour of lions and cheetahs in zoos and offer implications that could be useful for improving husbandry and management.
The success of the increasing use of technology in education is highly dependent on learner acceptance. Although the Technology Acceptance Model (TAM) is dominant in research for surveying acceptance of technology, it does not allow the prediction of a successful first time use of technology. The successful first time use can be determined with the survey of technology affinity, as it corresponds to the expression of certain personality traits of users and is thus detached from the specific technology. Since there are no measurement instruments for the educational sector so far and existing instruments for measuring technology affinity do not meet the specific requirements for use in the educational context (e.g., limited time for questioning), we present the single item Inclusion of Technology Affinity in Self-Scale (ITAS). In study 1 we provide evidence of convergent and discriminant validity within the general population so that a generalization of its applicability is possible. In study 2 we subsequently tested ITAS in the actual target group, the educational sector. The high correlations of the ITAS with the ATI and the control instrument TA-EG (ranging from rs = 0.679 to rs = 0.440) show that ITAS is suitable for use in research. Furthermore, the newly developed instrument convinces with its low complexity, the graphical component, which requires little text understanding and the high time saving. This research thus can contribute to the investigation of technology affinity in the educational sector helping educators to conduct technical activities with their learning group, to predict possible difficulties and adjust their planning accordingly.
Microplastics are small plastic fragments that are widely distributed in marine and terrestrial environments. While the soil ecosystem represents a large reservoir for plastic, research so far has focused mainly on the impact on aquatic ecosystems and there is a lack of information on the potentially adverse effects of microplastics on soil biota. Earthworms are key organisms of the soil ecosystem and are due to their crucial role in soil quality and fertility a suitable and popular model organism in soil ecotoxicology.
Therefore, the aim of this study was to gain insight into the effects of environmentally relevant concentrations of microplastics on the earthworm Eisenia andrei on multiple levels of biological organization after different exposure periods. Earthworms were exposed to two types of microplastics: (1) polystyrene-HBCD and (2) car tire abrasion in natural soil for 2, 7, 14 and 28 d. Acute and chronic toxicity and all subcellular investigations were conducted for all exposure times, avoidance behavior assessed after 48 h and reproduction after 28 d. Subcellular endpoints included enzymatic biomarker responses, namely, carboxylesterase, glutathione peroxidase, acetylcholinesterase, glutathione reductase, glutathione S-transferase and catalase activities, as well as fluorescence-based measurements of oxidative stress-related markers and multixenobiotic resistance activity. Multiple biomarkers showed significant changes in activity, but a recovery of most enzymatic activities could be observed after 28 d. Overall, only minor effects could be observed on a subcellular level, showing that in this exposure scenario with environmentally relevant concentrations based on German pollution levels the threat to soil biota is minimal. However, in areas with higher concentrations of microplastics in the environment, these results can be interpreted as an early warning signal for more adverse effects. In conclusion, these findings provide new insights regarding the ecotoxicological effects of environmentally relevant concentrations of microplastics on soil organisms.
Holocarpic oomycetes infecting freshwater diatoms are obligate endobiotic parasites reported from a wide range of habitats. So far, the taxonomy of and phylogeny of most species remains unresolved, since most have not been reported throughout the past decades and sequence data are available for only the four species, Aphanomycopsis bacillariacearum, Diatomophthora gillii, Ectrogella bacillariacearum, and the recently-discovered species Miracula moenusica. In the current study, a new freshwater diatom parasite resembling Ectrogella bacillariacearum in the sense of Scherffel was discovered from pennate diatoms (Ulnaria acus, Ulnaria ulna) collected from the small stream Einbúalækur on Víkurskarð, North Iceland and investigated for its life cycle and phylogenetic placement. In contrast to the original description, Scherffel reports an achlya-like spore discharge for Ectrogella bacillariacearum. The phylogenetic reconstruction and morphological characterisation in this study revealed that Scherffel’s E. bacillariacearum is largely unrelated to the epitype of the species and is a member of the early-diverging genus Miracula. Consequently, the new species is described as M. einbuarlaekurica in the present study. This adds a second freshwater member to the genus, demonstrating the high ecological adaptability of the genus, which thrives in both freshwater and marine ecosystems.
Despite islands contributing only 6.7% of land surface area, they harbor ~20% of the Earth's biodiversity, but unfortunately also ~50% of the threatened species and 75% of the known extinctions since the European expansion around the globe. Due to their geological and geographic history and characteristics, islands act simultaneously as cradles of evolutionary diversity and museums of formerly widespread lineages—elements that permit islands to achieve an outstanding endemicity. Nevertheless, the majority of these endemic species are inherently vulnerable due to genetic and demographic factors linked with the way islands are colonized. Here, we stress the great variation of islands in their physical geography (area, isolation, altitude, latitude) and history (age, human colonization, human density). We provide examples of some of the most species rich and iconic insular radiations. Next, we analyze the natural vulnerability of the insular biota, linked to genetic and demographic factors as a result of founder events as well as the typically small population sizes of many island species. We note that, whereas evolution toward island syndromes (including size shifts, derived insular woodiness, altered dispersal ability, loss of defense traits, reduction in clutch size) might have improved the ability of species to thrive under natural conditions on islands, it has simultaneously made island biota disproportionately vulnerable to anthropogenic pressures such as habitat loss, overexploitation, invasive species, and climate change. This has led to the documented extinction of at least 800 insular species in the past 500 years, in addition to the many that had already gone extinct following the arrival of first human colonists on islands in prehistoric times. Finally, we summarize current scientific knowledge on the ongoing biodiversity loss on islands worldwide and express our serious concern that the current trajectory will continue to decimate the unique and irreplaceable natural heritage of the world's islands. We conclude that drastic actions are urgently needed to bend the curve of the alarming rates of island biodiversity loss.
Spatial genome organization is tightly controlled by several regulatory mechanisms and is essential for gene expression control. Nuclear receptors are ligand-activated transcription factors that modulate physiological and pathophysiological processes and are primary pharmacological targets. DNA binding of the important loop-forming insulator protein CCCTC-binding factor (CTCF) was modulated by 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3). We performed CTCF HiChIP assays to produce the first genome-wide dataset of CTCF long-range interactions in 1,25(OH)2D3-treated cells, and to determine whether dynamic changes of spatial chromatin interactions are essential for fine-tuning of nuclear receptor signaling. We detected changes in 3D chromatin organization upon vitamin D receptor (VDR) activation at 3.1% of all observed CTCF interactions. VDR binding was enriched at both differential loop anchors and within differential loops. Differential loops were observed in several putative functional roles including TAD border formation, promoter-enhancer looping, and establishment of VDR-responsive insulated neighborhoods. Vitamin D target genes were enriched in differential loops and at their anchors. Secondary vitamin D effects related to dynamic chromatin domain changes were linked to location of downstream transcription factors in differential loops. CRISPR interference and loop anchor deletion experiments confirmed the functional relevance of nuclear receptor ligand-induced adjustments of the chromatin 3D structure for gene expression regulation.
Climate forecasts show that in many regions the temporal distribution of precipitation events will become less predictable. Root traits may play key roles in dealing with changes in precipitation predictability, but their functional plastic responses, including transgenerational processes, are scarcely known. We investigated root trait plasticity of Papaver rhoeas with respect to higher versus lower intra-seasonal and inter-seasonal precipitation predictability (i.e., the degree of temporal autocorrelation among precipitation events) during a four-year outdoor multi-generation experiment. We first tested how the simulated predictability regimes affected intra-generational plasticity of root traits and allocation strategies of the ancestors, and investigated the selective forces acting on them. Second, we exposed three descendant generations to the same predictability regime experienced by their mothers or to a different one. We then investigated whether high inter-generational predictability causes root trait differentiation, whether transgenerational root plasticity existed and whether it was affected by the different predictability treatments. We found that the number of secondary roots, root biomass and root allocation strategies of ancestors were affected by changes in precipitation predictability, in line with intra-generational plasticity. Lower predictability induced a root response, possibly reflecting a fast-acquisitive strategy that increases water absorbance from shallow soil layers. Ancestors’ root traits were generally under selection, and the predictability treatments did neither affect the strength nor the direction of selection. Transgenerational effects were detected in root biomass and root weight ratio (RWR). In presence of lower predictability, descendants significantly reduced RWR compared to ancestors, leading to an increase in performance. This points to a change in root allocation in order to maintain or increase the descendants’ fitness. Moreover, transgenerational plasticity existed in maximum rooting depth and root biomass, and the less predictable treatment promoted the lowest coefficient of variation among descendants’ treatments in five out of six root traits. This shows that the level of maternal predictability determines the variation in the descendants’ responses, and suggests that lower phenotypic plasticity evolves in less predictable environments. Overall, our findings show that roots are functional plastic traits that rapidly respond to differences in precipitation predictability, and that the plasticity and adaptation of root traits may crucially determine how climate change will affect plants.
In recent decades, a rapid range expansion of the golden jackal (Canis aureus) towards Northern and Western Europe has been observed. The golden jackal is a medium-sized canid, with a broad and flexible diet. Almost 200 different parasite species have been reported worldwide from C. aureus, including many parasites that are shared with dogs and cats and parasite species of public health concern. As parasites may follow the range shifts of their host, the range expansion of the golden jackal could be accompanied by changes in the parasite fauna in the new ecosystems. In the new distribution area, the golden jackal could affect ecosystem equilibrium, e.g., through changed competition situations or predation pressure. In a niche modeling approach, we project the future climatic habitat suitability of the golden jackal in Europe in the context of whether climatic changes promote range expansion. We use an ensemble forecast based on six presence-absence algorithms to estimate the climatic suitability of C. aureus for different time periods up to the year 2100 considering different IPCC scenarios on future development. As predictor variables, we used six bioclimatic variables provided by worldclim. Our results clearly indicate that areas with climatic conditions analogous to those of the current core distribution area of the golden jackal in Europe will strongly expand towards the north and the west in future decades. Thus, the observed range expansion may be favored by climate change. The occurrence of stable populations can be expected in Central Europe. With regard to biodiversity and public health concerns, the population and range dynamics of the golden jackal should be surveyed. Correlative niche models provide a useful and frequently applied tool for this purpose. The results can help to make monitoring more efficient by identifying areas with suitable habitat and thus a higher probability of occurrence.
Biodiversity patterns of marine crustaceans are still unknown in many locations or might have been overlooked due to our knowledge gaps, despite increasing sampling and data sharing efforts during the last decades. By analysing big data extracted from open portals such as Ocean Biodiversity Information System (OBIS) and Global Biodiversity Information System (GBIF), we aim to revisit the distribution and biodiversity patterns of the highly speciose and abundant Crustacea in the Northwest Pacific (NWP) from shallowest depths to the deep sea. This study focussed on selected benthic and pelagic crustacean (sub) classes and their species richness, sampling effort, and expected species richness (ES50) using equal/sized hexagonal cells, 5° latitudinal bands, 500 m depth intervals were analyzed. Crustacean species richness was highest in the tropical Philippines as well as around the Japanese islands. Pelagic crustacean species richness peaked at 30° latitude and declined beyond that. Benthic taxa; however, depicted high levels of species richness across most of the latitudinal gradient, reaching its highest point at 45° latitude. Due to the prevalence of certain crustacean orders in the deep sea, benthic species richness showed a distribution pattern with two distinct peaks across bathymetric gradients; with highest species richness recorded at shallow-water depths and also at abyssal depths. The most important environmental drivers of benthic and pelagic crustacean species richness were primary productivity (positive correlation) and salinity (negative correlation). Our study provides first insights into biodiversity patterns of the highly diverse Crustacea in the NWP and highlights strong differences between benthic and pelagic taxa. The results presented here could help us to better understand whether benthic or pelagic taxa might respond differently to climate changes in the NWP based on their distinct physiological and biological characteristics. This information is crucial in establishing species management strategies and ecosystem restorations in both shallow water and deep-sea environments.
Background: In the face of ongoing climate warming, vector-borne diseases are expected to increase in Europe, including tick-borne diseases (TBD). The most abundant tick-borne diseases in Germany are Tick-Borne Encephalitis (TBE) and Lyme Borreliosis (LB), with Ixodes ricinus as the main vector.
Methods: In this study, we display and compare the spatial and temporal patterns of reported cases of human TBE and LB in relation to some associated factors. The comparison may help with the interpretation of observed spatial and temporal patterns.
Results: The spatial patterns of reported TBE cases show a clear and consistent pattern over the years, with many cases in the south and only few and isolated cases in the north of Germany. The identification of spatial patterns of LB disease cases is more difficult due to the different reporting practices in the individual federal states. Temporal patterns strongly fluctuate between years, and are relatively synchronized between both diseases, suggesting common driving factors. Based on our results we found no evidence that weather conditions affect the prevalence of both diseases. Both diseases show a gender bias with LB bing more commonly diagnosed in females, contrary to TBE being more commonly diagnosed in males.
Conclusion: For a further investigation of of the underlying driving factors and their interrelations, longer time series as well as standardised reporting and surveillance system would be required.
In order to effectively address global environmental problems, it is important that future decision-makers in society are aware of the safe operation space for humans, which is limited by the planetary boundaries. Until now, however, there has been a lack of international studies examining how the planet's boundaries are perceived. In this study, we investigated how students of environmental and sustainability studies in 35 countries (n = 4140) assess the planetary boundaries. Based on the rating, using spectral clustering, the 35 countries were assigned to five different clusters. Four indicators (Human Development Index, Legatum Prosperity Index, Natural Resources Income and Forest Area) were used to provide explanations for the clustering result. The indices allow a distinction between the clusters and provide initial explanations for the clustering. The results provide important insights for today's decision-makers, as possible measures for action in the individual countries can be derived from the findings.
Background: In times of global warming there is an urgent need to replace fossil fuel-based energy vectors by less carbon dioxide (CO2)-emitting alternatives. One attractive option is the use of molecular hydrogen (H2) since its combustion emits water (H2O) and not CO2. Therefore, H2 is regarded as a non-polluting fuel. The ways to produce H2 can be diverse, but steam reformation of conventional fossil fuel sources is still the main producer of H2 gas up to date. Biohydrogen production via microbes could be an alternative, environmentally friendly and renewable way of future H2 production, especially when the flexible and inexpensive C1 compound formate is used as substrate.
Results: In this study, the versatile compound formate was used as substrate to drive H2 production by whole cells of the thermophilic acetogenic bacterium Thermoanaerobacter kivui which harbors a highly active hydrogen-dependent CO2 reductase (HDCR) to oxidize formate to H2 and CO2 and vice versa. Under optimized reaction conditions, T. kivui cells demonstrated the highest H2 production rates (qH2 = 685 mmol g−1 h−1) which were so far reported in the literature for wild-type organisms. Additionally, high yields (Y(H2/formate)) of 0.86 mol mol−1 and a hydrogen evolution rate (HER) of 999 mmol L−1 h−1 were observed. Finally, stirred-tank bioreactor experiments demonstrated the upscaling feasibility of the applied whole cell system and indicated the importance of pH control for the reaction of formate-driven H2 production.
Conclusions: The thermophilic acetogenic bacterium T. kivui is an efficient biocatalyst for the oxidation of formate to H2 (and CO2). The existing genetic tool box of acetogenic bacteria bears further potential to optimize biohydrogen production in future and to contribute to a future sustainable formate/H2 bio-economy.
The ORCID iDs are missing for the second, fifth, and sixth authors. Please see the authors’ respective ORCID iDs here:
Author Christine Hertler’s ORCID iD is: 0000-0002-8252-9674 (https://orcid.org/0000-0002-8252-9674).
Author Jan Ole Berndt’s ORCID iD is: 0000-0001-7241-3291 (https://orcid.org/0000-0001-7241-3291).
Author Ingo J. Timm’s ORCID iD is: 0000-0002-3369-813X (https://orcid.org/0000-0002-3369-813X).
Understanding hominin expansions requires the comprehension of movement processes at different scales. In many models of hominin expansion these processes are viewed as being determined by large-scale effects, such as changes in climate and vegetation spanning continents and thousands or even millions of years. However, these large-scale patterns of expansions also need to be considered as possibly resulting from the accumulation of small-scale decisions of individual hominins. Moving on a continental scale may for instance involve crossing a water barrier. We present a generalized agent-based model for simulating the crossing of a water barrier where the agents represent the hominin individuals. The model can be configured to represent a variety of movement modes across water. Here, we compare four different behavioral scenarios in conjunction with a set of water barrier configurations, in which agents move in water by either paddling, drifting, swimming or rafting. We introduce the crossing-success-rate (CSR) to quantify the performance in water crossing. Our study suggests that more focus should be directed towards the exploration of behavioral models for hominins, as directionality may be a more powerful factor for crossing a barrier than environmental opportunities alone. A prerequisite for this is to perceive the opposite shore. Furthermore, to provide a comprehensive understanding of hominin expansions, the CSR allows for the integration of results obtained from small-scale simulations into large-scale models for hominin expansion.
Translation is an important step in gene expression. Initiation of translation is rate-limiting, and it is phylogenetically more diverse than elongation or termination. Bacteria contain only three initiation factors. In stark contrast, eukaryotes contain more than 10 (subunits of) initiation factors (eIFs). The genomes of archaea contain many genes that are annotated to encode archaeal homologs of eukaryotic initiation factors (aIFs). However, experimental characterization of aIFs is scarce and mostly restricted to very few species. To broaden the view, the protein–protein interaction network of aIFs in the halophilic archaeon Haloferax volcanii has been characterized. To this end, tagged versions of 14 aIFs were overproduced, affinity isolated, and the co-isolated binding partners were identified by peptide mass fingerprinting and MS/MS analyses. The aIF–aIF interaction network was resolved, and it was found to contain two interaction hubs, (1) the universally conserved factor aIF5B, and (2) a protein that has been annotated as the enzyme ribose-1,5-bisphosphate isomerase, which we propose to rename to aIF2Bα. Affinity isolation of aIFs also led to the co-isolation of many ribosomal proteins, but also transcription factors and subunits of the RNA polymerase (Rpo). To analyze a possible coupling of transcription and translation, seven tagged Rpo subunits were overproduced, affinity isolated, and co-isolated proteins were identified. The Rpo interaction network contained many transcription factors, but also many ribosomal proteins as well as the initiation factors aIF5B and aIF2Bα. These results showed that transcription and translation are coupled in haloarchaea, like in Escherichia coli. It seems that aIF5B and aIF2Bα are not only interaction hubs in the translation initiation network, but also key players in the transcription-translation coupling.
What is in Umbilicaria pustulata? A metagenomic approach to reconstruct the holo-genome of a lichen
(2020)
Lichens are valuable models in symbiosis research and promising sources of biosynthetic genes for biotechnological applications. Most lichenized fungi grow slowly, resist aposymbiotic cultivation, and are poor candidates for experimentation. Obtaining contiguous, high-quality genomes for such symbiotic communities is technically challenging. Here, we present the first assembly of a lichen holo-genome from metagenomic whole-genome shotgun data comprising both PacBio long reads and Illumina short reads. The nuclear genomes of the two primary components of the lichen symbiosis—the fungus Umbilicaria pustulata (33 Mb) and the green alga Trebouxia sp. (53 Mb)—were assembled at contiguities comparable to single-species assemblies. The analysis of the read coverage pattern revealed a relative abundance of fungal to algal nuclei of ∼20:1. Gap-free, circular sequences for all organellar genomes were obtained. The bacterial community is dominated by Acidobacteriaceae and encompasses strains closely related to bacteria isolated from other lichens. Gene set analyses showed no evidence of horizontal gene transfer from algae or bacteria into the fungal genome. Our data suggest a lineage-specific loss of a putative gibberellin-20-oxidase in the fungus, a gene fusion in the fungal mitochondrion, and a relocation of an algal chloroplast gene to the algal nucleus. Major technical obstacles during reconstruction of the holo-genome were coverage differences among individual genomes surpassing three orders of magnitude. Moreover, we show that GC-rich inverted repeats paired with nonrandom sequencing error in PacBio data can result in missing gene predictions. This likely poses a general problem for genome assemblies based on long reads.
Impact of biological education and gender on students' connection to nature and relational values
(2020)
The new concept of relational values (RVs) is gaining more and more attention in environmental research, but empirical analyses are still rare. However, this type of research is necessary because the RVs have an influence on environmental behavior. To evaluate the impact of biological education on attributing higher importance to RVs and connectedness to nature, we compared the connection to nature scores (using the inclusion of nature scale (INS) and connectedness to nature scale (CNS)) and RV scores of biologically interested high school students (n = 417) with first year (n = 593) and advanced biology (n = 223) students. While high school students showed significant lower connection to nature scores than university students, there was no significant difference in RVs between the test groups. These results suggest that there is a lack of factors in the university study of biology that can change RVs. The gender comparison of RVs and connection to nature showed a significant higher RV score for females while INS and CNS did not show a gender difference. Thus, the study makes an important contribution to the research, as it was able to prove that gender has an influence on a person's RVs but not on their connection to nature.
Eukaryotic ribosome assembly starts in the nucleolus, where the ribosomal DNA (rDNA) is transcribed into the 35S pre-ribosomal RNA (pre-rRNA). More than two-hundred ribosome biogenesis factors (RBFs) and more than two-hundred small nucleolar RNAs (snoRNA) catalyze the processing, folding and modification of the rRNA in Arabidopsis thaliana. The initial pre-ribosomal 90S complex is formed already during transcription by association of ribosomal proteins (RPs) and RBFs. In addition, small nucleolar ribonucleoprotein particles (snoRNPs) composed of snoRNAs and RBFs catalyze the two major rRNA modification types, 2′-O-ribose-methylation and pseudouridylation. Besides these two modifications, rRNAs can also undergo base methylations and acetylation. However, the latter two modifications have not yet been systematically explored in plants. The snoRNAs of these snoRNPs serve as targeting factors to direct modifications to specific rRNA regions by antisense elements. Today, hundreds of different sites of modifications in the rRNA have been described for eukaryotic ribosomes in general. While our understanding of the general process of ribosome biogenesis has advanced rapidly, the diversities appearing during plant ribosome biogenesis is beginning to emerge. Today, more than two-hundred RBFs were identified by bioinformatics or biochemical approaches, including several plant specific factors. Similarly, more than two hundred snoRNA were predicted based on RNA sequencing experiments. Here, we discuss the predicted and verified rRNA modification sites and the corresponding identified snoRNAs on the example of the model plant Arabidopsis thaliana. Our summary uncovers the plant modification sites in comparison to the human and yeast modification sites.
Predator-induced plasticity in life-history and antipredator traits during the larval period has been extensively studied in organisms with complex life-histories. However, it is unclear whether different levels of predation could induce warning signals in aposematic organisms. Here, we investigated whether predator-simulated handling affects warning coloration and life-history traits in the aposematic wood tiger moth larva, Arctia plantaginis. As juveniles, a larger orange patch on an otherwise black body signifies a more efficient warning signal against predators but this comes at the costs of conspicuousness and thermoregulation. Given this, one would expect that an increase in predation risk would induce flexible expression of the orange patch. Prior research in this system points to plastic effects being important as a response to environmental changes for life history traits, but we had yet to assess whether this was the case for predation risk, a key driver of this species evolution. Using a full-sib rearing design, in which individuals were reared in the presence and absence of a non-lethal simulated bird attack, we evaluated flexible responses of warning signal size (number of orange segments), growth, molting events, and development time in wood tiger moths. All measured traits except development time showed a significant response to predation. Larvae from the predation treatment developed a more melanized warning signal (smaller orange patch), reached a smaller body size, and molted more often. Our results suggest plasticity is indeed important in aposematic organisms, but in this case may be complicated by the trade-off between costly pigmentation and other life-history traits.
Cercosporoid fungi (Mycosphaerellaceae, Mycosphaerellales, Ascomycota) are one of the largest and most diverse groups of hyphomycetes causing a wide range of diseases of economically important plants as well as of plants in the wild. Although more than 6000 species are known for this group, the documentation of this fungal group is far from complete. Especially in the tropics, the diversity of cercosporoid fungi is poorly known. The present study aims to identify and characterise cercosporoid fungi collected on host plants belonging to Fabaceae in Benin, West Africa. Information on their morphology, host species and DNA sequence data (18S rDNA, 28S rDNA, ITS and tef1) is provided. DNA sequence data were obtained by a simple and non-culture-based method for DNA isolation which has been applied for cercosporoid fungi for the first time in the context of the present study. Among the loci used for the phylogenetic analysis, tef1 provided the best resolution together with the multigene dataset. Species delimitation in many cases, however, was only possible by combining molecular sequence data with morphological characteristics. Based on forty specimens recently collected in Benin, 18 species are presented with morphological descriptions, illustrations and sequence data. Among these, six species in the genus Cercospora and two species in Pseudocercospora are proposed as species new to science. The newly described species are Cercospora (C.) beninensis on Crotalaria macrocalyx, C. parakouensis on Desmodium tortuosum, C. rhynchophora on Vigna unguiculata, C. vignae-subterraneae on Vigna subterranea, C. tentaculifera on Vigna unguiculata, C. zorniicola on Zornia glochidiata, Pseudocercospora sennicola on Senna occidentalis and Pseudocercospora tabei on Vigna unguiculata. Eight species of cercosporoid fungi are reported for Benin for the first time, three of them, namely C. cf. canscorina, C. cf. fagopyri and C. phaseoli-lunati are new for West Africa. The presence of two species of cercosporoid fungi on Fabaceae previously reported from Benin, namely Nothopassalora personata and Passalora arachidicola, is confirmed.
Measuring connection to nature - a illustrated extension of the inclusion of nature in self scale
(2021)
The human-nature connection is an important factor that is frequently the subject of environmental education research and environmental psychology. Therefore, over the years, numerous measuring instruments have been established to quantitatively record a person’s connection to nature. However, there is no instrument specifically for children with cognitive limitations. For this reason, in this study, an established scale for connection to nature, the inclusion of nature in self scale (INS), was modified especially for the needs of this group. Study 1 investigated what students understand by the term “nature” in order to create an illustrated version of the INS. In study 2, the new instrument was tested on university students and compared with the original INS and the connectedness to nature scale (CNS). No significant differences between the original INS and the new developed scale were found (p = 0.247), from which it can be concluded that the illustrated INS (IINS) measures the connection to nature with similar accuracy as the original INS. In study 3, the instrument was tested together with other established nature connection instruments on the actual target group, students with disabilities. The correlation between the IINS, the CNS, and nature connectedness scale (NR) were in accordance with the expected literature values (rIINS-CNS = 0.570 & rIINS-NR = 0.605). The results of this study also prove effectiveness of the developed illustrated scale. This research thus provides a suitable measuring instrument for people with learning difficulties and can make a contribution to the investigation of human-nature connections and conservation education.
Gene conversion is defined as the non-reciprocal transfer of genetic information from one site to a homologous, but not identical site of the genome. In prokaryotes, gene conversion can increase the variance of sequences, like in antigenic variation, but can also lead to a homogenization of sequences, like in the concerted evolution of multigene families. In contrast to these intramolecular mechanisms, the intermolecular gene conversion in polyploid prokaryotes, which leads to the equalization of the multiple genome copies, has hardly been studied. We have previously shown the intermolecular gene conversion in halophilic and methanogenic archaea is so efficient that it can be studied without selecting for conversion events. Here, we have established an approach to characterize unselected intermolecular gene conversion in Haloferax volcanii making use of two genes that encode enzymes involved in carotenoid biosynthesis. Heterozygous strains were generated by protoplast fusion, and gene conversion was quantified by phenotype analysis or/and PCR. It was verified that unselected gene conversion is extremely efficient and it was shown that gene conversion tracts are much longer than in antigenic variation or concerted evolution in bacteria. Two sites were nearly always co-converted when they were 600 bp apart, and more than 30% co-conversion even occurred when two sites were 5 kbp apart. The gene conversion frequency was independent from the extent of genome differences, and even a one nucleotide difference triggered conversion.
The geomagnetic field provides directional information for birds. The avian magnetic compass is an inclination compass that uses not the polarity of the magnetic field but the axial course of the field lines and their inclination in space. It works in a flexible functional window, and it requires short-wavelength light. These characteristics result from the underlying sensory mechanism based on radical pair processes in the eyes, with cryptochrome suggested as the receptor molecule. The chromophore of cryptochrome, flavin adenine dinucleotide (FAD), undergoes a photocycle, where radical pairs are formed during photo-reduction as well as during re-oxidation; behavioral data indicate that the latter is crucial for detecting magnetic directions. Five types of cryptochromes are found in the retina of birds: cryptochrome 1a (Cry1a), cryptochrome 1b, cryptochrome 2, cryptochrome 4a, and cryptochrome 4b. Because of its location in the outer segments of the ultraviolet cones with their clear oil droplets, Cry1a appears to be the most likely receptor molecule for magnetic compass information.
Inflammatory nontraumatic atlantoaxial rotatory subluxation (AAS) in children is an often-missed diagnosis, especially in the early stages of disease. Abscess formation and spinal cord compression are serious risks that call for immediate surgical attention. Neither radiographs nor non-enhanced computed tomography (CT) images sufficiently indicate inflammatory processes. Magnetic resonance imaging (MRI) allows a thorough evaluation of paraspinal soft tissues, joints, and ligaments. In addition, it can show evidence of vertebral distraction and spinal cord compression. After conducting a scoping review of the literature, along with scientific and practical considerations, we outlined a standardized pediatric MRI protocol for suspected inflammatory nontraumatic AAS. We recommend contrast-enhanced MRI as the primary diagnostic imaging modality in children with signs of torticollis in combination with nasopharyngeal inflammatory or ear nose and throat (ENT) surgical history.
Microglia, the primary immune cells of the central nervous system, hold a multitude of tasks in order to ensure brain homeostasis and are one of the best predictors of biological age on a cellular level. We and others have shown that these long-lived cells undergo an aging process that impedes their ability to perform some of the most vital homeostatic functions such as immune surveillance, acute injury response, and clearance of debris. Microglia have been described as gradually transitioning from a homeostatic state to an activated state in response to various insults, as well as aging. However, microglia show diverse responses to presented stimuli in the form of acute injury or chronic disease. This complexity is potentially further compounded by the distinct alterations that globally occur in the aging process. In this review, we discuss factors that may contribute to microglial aging, as well as transcriptional microglia alterations that occur in old age. We then compare these distinct phenotypic changes with microglial phenotype in neurodegenerative disease.
Research on Podospora anserina unraveled a network of molecular pathways affecting biological aging. In particular, a number of pathways active in the control of mitochondria were identified on different levels. A long-known key process active during aging of P. anserina is the age- related reorganization of the mitochondrial DNA (mtDNA). Mechanisms involved in the stabilization of the mtDNA lead to lifespan extension. Another critical issue is to balance mitochondrial levels of reactive oxygen species (ROS). This is important because ROS are essential signaling molecules, but at increased levels cause molecular damage. At a higher level of the network, mechanisms are active in the repair of damaged compounds. However, if damage passes critical limits, the corresponding pathways are overwhelmed and impaired molecules as well as those present in excess are degraded by specific enzymes or via different forms of autophagy. Subsequently, degraded units need to be replaced by novel functional ones. The corresponding processes are dependent on the availability of intact genetic information. Although a number of different pathways involved in the control of cellular homeostasis were uncovered in the past, certainly many more exist. In addition, the signaling pathways involved in the control and coordination of the underlying pathways are only initially understood. In some cases, like the induction of autophagy, ROS are active. Additionally, sensing and signaling the energetic status of the organism plays a key role. The precise mechanisms involved are elusive and remain to be elucidated.
Mitochondrial F1Fo-ATP-synthase dimers play a critical role in shaping and maintenance of mitochondrial ultrastructure. Previous studies have revealed that ablation of the F1Fo-ATP-synthase assembly factor PaATPE of the ascomycete Podospora anserina strongly affects cristae formation, increases hydrogen peroxide levels, impairs mitochondrial function and leads to premature cell death. In the present study, we investigated the underlying mechanistic basis. Compared to the wild type, we observed a slight increase in non-selective and a pronounced increase in mitophagy, the selective vacuolar degradation of mitochondria. This effect depends on the availability of functional cyclophilin D (PaCYPD), the regulator of the mitochondrial permeability transition pore (mPTP). Simultaneous deletion of PaAtpe and PaAtg1, encoding a key component of the autophagy machinery or of PaCypD, led to a reduction of mitophagy and a partial restoration of the wild-type specific lifespan. The same effect was observed in the PaAtpe deletion strain after inhibition of PaCYPD by its specific inhibitor, cyclosporin A. Overall, our data identify autophagy-dependent cell death (ADCD) as part of the cellular response to impaired F1Fo-ATP-synthase dimerization, and emphasize the crucial role of functional mitochondria in aging.
Nomadic movements are often a consequence of unpredictable resource dynamics. However, how nomadic ungulates select dynamic resources is still understudied. Here we examined resource selection of nomadic Mongolian gazelles (Procapra gutturosa) in the Eastern Steppe of Mongolia. We used daily GPS locations of 33 gazelles tracked up to 3.5 years. We examined selection for forage during the growing season using the Normalized Difference Vegetation Index (NDVI). In winter we examined selection for snow cover which mediates access to forage and drinking water. We studied selection at the population level using resource selection functions (RSFs) as well as on the individual level using step-selection functions (SSFs) at varying spatio-temporal scales from 1 to 10 days. Results from the population and the individual level analyses differed. At the population level we found selection for higher than average NDVI during the growing season. This may indicate selection for areas with more forage cover within the arid steppe landscape. In winter, gazelles selected for intermediate snow cover, which may indicate preference for areas which offer some snow for hydration but not so much as to hinder movement. At the individual level, in both seasons and across scales, we were not able to detect selection in the majority of individuals, but selection was similar to that seen in the RSFs for those individuals showing selection. Difficulty in finding selection with SSFs may indicate that Mongolian gazelles are using a random search strategy to find forage in a landscape with large, homogeneous areas of vegetation. The combination of random searches and landscape characteristics could therefore obscure results at the fine scale of SSFs. The significant results on the broader scale used for the population level RSF highlight that, although individuals show uncoordinated movement trajectories, they ultimately select for similar vegetation and snow cover.
Identification and regulation of tomato Serine/Arginine-rich proteins under high temperatures
(2021)
Alternative splicing is an important mechanism for the regulation of gene expression in eukaryotes during development, cell differentiation or stress response. Alterations in the splicing profiles of genes under high temperatures that cause heat stress (HS) can impact the maintenance of cellular homeostasis and thermotolerance. Consequently, information on factors involved in HS-sensitive alternative splicing is required to formulate the principles of HS response. Serine/arginine-rich (SR) proteins have a central role in alternative splicing. We aimed for the identification and characterization of SR-coding genes in tomato (Solanum lycopersicum), a plant extensively used in HS studies. We identified 17 canonical SR and two SR-like genes. Several SR-coding genes show differential expression and altered splicing profiles in different organs as well as in response to HS. The transcriptional induction of five SR and one SR-like genes is partially dependent on the master regulator of HS response, HS transcription factor HsfA1a. Cis-elements in the promoters of these SR genes were predicted, which can be putatively recognized by HS-induced transcription factors. Further, transiently expressed SRs show reduced or steady-state protein levels in response to HS. Thus, the levels of SRs under HS are regulated by changes in transcription, alternative splicing and protein stability. We propose that the accumulation or reduction of SRs under HS can impact temperature-sensitive alternative splicing.
The combined behaviours of individuals within insect societies determine the survival and development of the colony. For the western honey bee (Apis mellifera), individual behaviours include nest building, foraging, storing and ripening food, nursing the brood, temperature regulation, hygiene and defence. However, the various behaviours inside the colony, especially within the cells, are hidden from sight, and until recently, were primarily described through texts and line drawings, which lack the dynamics of moving images. In this study, we provide a comprehensive source of online video material that offers a view of honey bee behaviour within comb cells, thereby providing a new mode of observation for the scientific community and the general public. We analysed long-term video recordings from longitudinally truncated cells, which allowed us to see sideways into the cells in the middle of a colony. Our qualitative study provides insight into worker behaviours, including the use of wax scales and existing nest material to remodel combs, storing pollen and nectar in cells, brood care and thermoregulation, and hygienic practices, such as cannibalism, grooming and surface cleaning. We reveal unique processes that have not been previously published, such as the rare mouth-to-mouth feeding by nurses to larvae as well as thermoregulation within cells containing the developing brood. With our unique video method, we are able to bring the processes of a fully functioning social insect colony into classrooms and homes, facilitating ecological awareness in modern times. We provide new details and images that will help scientists test their hypotheses on social behaviours. In addition, we encourage the non-commercial use of our material to educate beekeepers, the media and the public and, in turn, call attention to the general decline of insect biomass and diversity.
Organismic aging is known to be controlled by genetic and environmental traits. Pathways involved in the control of cellular metabolism play a crucial role. Previously, we identified a role of PaCLPP, a mitochondrial matrix protease, in the control of the mitochondrial energy metabolism, aging, and lifespan of the fungal aging model Podospora anserina. Most surprisingly, we made the counterintuitive observation that the ablation of this component of the mitochondrial quality control network leads to lifespan extension. In the current study, we investigated the role of energy metabolism of P. anserina. An age-dependent metabolome analysis of the wild type and a PaClpP deletion strain verified differences and changes of various metabolites in cultures of the PaClpP mutant and the wild type. Based on these data, we generated and analyzed a PaSnf1 deletion mutant and a ΔPaSnf1/ΔPaClpP double mutant. In both mutants PaSNF1, the catalytic α-subunit of AMP-activated protein kinase (AMPK) is ablated. PaSNF1 was found to be required for the development of fruiting bodies and ascospores and the progeny of sexual reproduction of this ascomycete and impact mitochondrial dynamics and autophagy. Most interestingly, while the single PaSnf1 deletion mutant is characterized by a slight lifespan increase, simultaneous deletion of PaSnf1 and PaClpP leads to a pronounced lifespan extension. This synergistic effect is strongly reinforced in the presence of the mating-type “minus”-linked allele of the rmp1 gene. Compared to the wild type, culture temperature of 35°C instead of the standard laboratory temperature of 27°C leads to a short-lived phenotype of the ΔPaSnf1/ΔPaClpP double mutant. Overall, our study provides novel evidence for complex interactions of different molecular pathways involved in mitochondrial quality control, gene expression, and energy metabolism in the control of organismic aging.
Plastid DNA sequence data have been traditionally widely used in plant phylogenetics because of the high copy number of plastids, their uniparental inheritance, and the blend of coding and non-coding regions with divergent substitution rates that allow the reconstruction of phylogenetic relationships at different taxonomic ranks. In the present study, we evaluate the utility of the plastome for the reconstruction of phylogenetic relationships in the pantropical plant family Ochnaceae (Malpighiales). We used the off-target sequence read fraction of a targeted sequencing study (targeting nuclear loci only) to recover more than 100 kb of the plastid genome from the majority of the more than 200 species of Ochnaceae and all but two genera using de novo and reference-based assembly strategies. Most of the recalcitrant nodes in the family’s backbone were resolved by our plastome-based phylogenetic inference, corroborating the most recent classification system of Ochnaceae and findings from a phylogenomic study based on nuclear loci. Nonetheless, the phylogenetic relationships within the major clades of tribe Ochnineae, which comprise about two thirds of the family’s species diversity, received mostly low support. Generally, the phylogenetic resolution was lowest at the infrageneric level. Overall there was little phylogenetic conflict compared to a recent analysis of nuclear loci. Effects of taxon sampling were invoked as the most likely reason for some of the few well-supported discords. Our study demonstrates the utility of the off-target fraction of a target enrichment study for assembling near-complete plastid genomes for a large proportion of samples.
Human GLUT2 and GLUT3, members of the GLUT / SLC2 gene family, facilitate glucose transport in specific tissues. Their malfunction or misregulation is associated with serious diseases, including diabetes, metabolic syndrome, and cancer. Despite being promising drug targets, GLUTs have only a few specific inhibitors. To identify and characterize potential GLUT2 and GLUT3 ligands, we developed a whole-cell system based on a yeast strain deficient in hexose uptake, whose growth defect on glucose can be rescued by the functional expression of human transporters. The simplicity of handling yeast cells makes this platform convenient for screening potential GLUT2 and GLUT3 inhibitors in a growth-based manner, amenable to high-throughput approaches. Moreover, our expression system is less laborious for detailed kinetic characterization of inhibitors than alternative methods such as the preparation of proteoliposomes or uptake assays in Xenopus oocytes. We show that functional expression of GLUT2 in yeast requires the deletion of the extended extracellular loop connecting transmembrane domains TM1 and TM2, which appears to negatively affect the trafficking of the transporter in the heterologous expression system. Furthermore, single amino acid substitutions at specific positions of the transporter sequence appear to positively affect the functionality of both GLUT2 and GLUT3 in yeast. We show that these variants are sensitive to known inhibitors phloretin and quercetin, demonstrating the potential of our expression systems to significantly accelerate the discovery of compounds that modulate the hexose transport activity of GLUT2 and GLUT3.
In times of global warming caused by the extensive use of fossil fuels, the need to capture gaseous carbon compounds is growing bigger. Several groups of microorganisms can fix the greenhouse gas CO2. Out of these, acetogenic bacteria are role models in their ability to reduce CO2 with hydrogen to acetate, which makes acetogens prime candidates for genetic modification towards biotechnological production of value-added compounds from CO2, such as biofuels. However, growth of acetogens on gaseous substrates is strongly energy-limited, and successful metabolic engineering requires a detailed knowledge of the bioenergetics. In 1939, Clostridium aceticum was the first acetogen to be described. A recent genomic study revealed that this organism contains cytochromes and therefore may use a proton gradient in its respiratory chain. We have followed up these studies and will present data that C. aceticum does not use a H+ but a Na+ gradient for ATP synthesis, established by a Na+-Rnf. Experimental data and in silico analyses enabled us to propose the biochemistry and bioenergetics of acetogenesis from H2 + CO2 in C. aceticum.
Background: More than 170 species of tabanids are known in Europe, with many occurring only in limited areas or having become very rare in the last decades. They continue to spread various diseases in animals and are responsible for livestock losses in developing countries. The current monitoring and recording of horseflies is mainly conducted throughout central Europe, with varying degrees of frequency depending on the country. To the detriment of tabanid research, little cooperation exists between western European and Eurasian countries.
Methods: For these reasons, we have compiled available sources in order to generate as complete a dataset as possible of six horsefly species common in Europe. We chose Haematopota pluvialis, Chrysops relictus, C. caecutiens, Tabanus bromius, T. bovinus and T. sudeticus as ubiquitous and abundant species within Europe. The aim of this study is to estimate the distribution, land cover usage and niches of these species. We used a surface-range envelope (SRE) model in accordance with our hypothesis of an underestimated distribution based on Eurocentric monitoring regimes.
Results: Our results show that all six species have a wide range in Eurasia, have a broad climatic niche and can therefore be considered as widespread generalists. Areas with modelled habitat suitability cover the observed distribution and go far beyond these. This supports our assumption that the current state of tabanid monitoring and the recorded distribution significantly underestimates the actual distribution. Our results show that the species can withstand extreme weather and climatic conditions and can be found in areas with only a few frost-free months per year. Additionally, our results reveal that species prefer certain land-cover environments and avoid other land-cover types.
Conclusions: The SRE model is an effective tool to calculate the distribution of species that are well monitored in some areas but poorly in others. Our results support the hypothesis that the available distribution data underestimate the actual distribution of the surveyed species.
The subfamily Bromelioideae is one of the most diverse groups among the neotropical Bromeliaceae. Previously, key innovations have been identified which account for the extraordinary radiation and species richness of this subfamily, especially in the so-called core Bromelioideae. However, in order to extend our understanding of the evolutionary mechanisms, the genomic mechanisms (e.g. polyploidy, dysploidy) that potentially underlie this accelerated speciation also need to be tested. Here, using PI and DAPI staining and flow cytometry we estimated genome size and GC content of 231 plants covering 30 genera and 165 species and combined it with published data. The evolutionary and ecological significance of all three genomic characters was tested within a previously generated dated phylogenetic framework using ancestral state reconstructions, comparative phylogenetic methods, and multiple regressions with climatic variables. The absolute genome size (2C) of Bromelioideae varied between 0.59 and 4.11 pg, and the GC content ranged between 36.73 and 41.43%. The monoploid genome sizes (Cx) differed significantly between core and early diverging lineages. The occurrence of dysploidy and polyploidy was, with few exceptions, limited to the phylogenetically isolated early diverging tank-less lineages. For Cx and GC content Ornstein–Uhlenbeck models outperformed the Brownian motion models suggesting adaptive potential linked to the temperature conditions. 2C-values revealed different rates of evolution in core and early diverging lineages also related to climatic conditions. Our results suggest that polyploidy is not associated with higher net diversification and fast radiation in core bromelioids. On the other hand, although coupled with higher extinction rates, dysploidy, polyploidy, and resulting genomic reorganizations might have played a role in the survival of the early diverging bromelioids in hot and arid environments.
Soil degradation can have an impact on the soil microbiota, but its specific effects on soil fungal communities are poorly understood. In this work, we studied the impact of soil degradation on the richness and diversity of communities of soil fungi, including three different degrees of degradation in Germany and Panama. Soil fungi were isolated monthly using the soil-sprinkling method for 8 months in Germany and 3 months in Panama, and characterized by morphological and molecular data. Soil physico-chemical properties were measured and correlated with the observed values of fungal diversity. We isolated a total of 71 fungal species, 47 from Germany, and 32 from Panama. Soil properties were not associated with fungal richness, diversity, or composition in soils, with the exception of soil compaction in Germany. The geographic location was a strong determinant of the soil fungal species composition although in both countries there was dominance by members of the orders Eurotiales and Hypocreales. In conclusion, the results of this work do not show any evident influence of soil degradation on communities of soil fungi in Germany or Panama.
The Culex pipiens complex encompasses five species and subspecies of the genus Culex. Over time, a multitude of morphologically indistinguishable species has been assigned to this complex with several species being classified as important vectors for different diseases. Some species of this complex hibernate in subterranean habitats, and it has been proven that viruses can survive this phase of hibernation. However, studies focusing on the environmental requirements, ecology and spatial and temporal distribution patterns of mosquitos in underground habitats are sparse. Here, we investigate the main environmental factors and dependencies of Culex, considering the number of individuals and survival probabilities in underground habitats during the winter months. Methods. Since the State of Hesse, Germany harbors about 3500 to 4000 subterranean shelters ample availability of subterranean habitats there provides a good opportunity to conduct detailed investigations of the Culex pipiens complex. In this study, we identified a sample of 727 specimens of overwintering females within the Culex pipiens complex from 52 different underground sites collected over a period of 23 years using qPCR. A complete data set of samplings of hibernating mosquitos from 698 subterranean habitats in Central Germany over the same period was available to study the spatial and temporal patterns and the effect of temperature and precipitation conditions on these hibernating populations using a generalized linear model (GLM). Results. Our qPCR-results show, similar to aboveground studies of mosquitos, that Culex pipiens pipiens and Culex torrentium occur sympatrically. On the other hand, Culex pipiens molestus occurred very rarely. The GLM revealed no shifts in species composition over time, but different preferences for subterranean hibernacula, chemical effects on overwintering populations as well as effects of annual and seasonal mean temperature and precipitation during the active phase from March to November. Cx. p. pipiens and Cx. torrentium are the most common species within Hessian caves and other underground habitats during winter. They co-occur with different frequency without any patterns in species composition. Weather conditions influence the number of overwintering mosquitos during the activity phase. Depending on cave parameters, the number of mosquitos decreases during the winter months.
Iron is part of many redox and other enzymes and, thus, it is essential for all living beings. Many oxic environments have extremely low concentrations of free iron. Therefore, many prokaryotic species evolved siderophores, i.e., small organic molecules that complex Fe3+ with very high affinity. Siderophores of bacteria are intensely studied, in contrast to those of archaea. The haloarchaeon Haloferax volcanii contains a gene cluster that putatively encodes siderophore biosynthesis genes, including four iron uptake chelate (iuc) genes. Underscoring this hypothesis, Northern blot analyses revealed that a hexacistronic transcript is generated that is highly induced under iron starvation. A quadruple iuc deletion mutant was generated, which had a growth defect solely at very low concentrations of Fe3+, not Fe2+. Two experimental approaches showed that the wild type produced and exported an Fe3+-specific siderophore under low iron concentrations, in contrast to the iuc deletion mutant. Bioinformatic analyses revealed that haloarchaea obtained the gene cluster by lateral transfer from bacteria and enabled the prediction of enzymatic functions of all six gene products. Notably, a biosynthetic pathway is proposed that starts with aspartic acid, uses several group donors and citrate, and leads to the hydroxamate siderophore Schizokinen.
Microthlaspi erraticum is widely distributed in temperate Eurasia, but restricted to Ca2+-rich habitats, predominantly on white Jurassic limestone, which is made up by calcium carbonate, with little other minerals. Thus, naturally occurring Microthlaspi erraticum individuals are confronted with a high concentration of Ca2+ ions while Mg2+ ion concentration is relatively low. As there is a competitive uptake between these two ions, adaptation to the soil condition can be expected. In this study, it was the aim to explore the genomic consequences of this adaptation by sequencing and analysing the genome of Microthlaspi erraticum. Its genome size is comparable with other diploid Brassicaceae, while more genes were predicted. Two Mg2+ transporters known to be expressed in roots were duplicated and one showed a significant degree of positive selection. It is speculated that this evolved due to the pressure to take up Mg2+ ions efficiently in the presence of an overwhelming amount of Ca2+ ions. Future studies on plants specialized on similar soils and affinity tests of the transporters are needed to provide unequivocal evidence for this hypothesis. If verified, the transporters found in this study might be useful for breeding Brassicaceae crops for higher yield on Ca2+-rich and Mg2+ -poor soils.
Tsetse flies are the transmitting vector of trypanosomes causing human sleeping sickness and animal trypanosomiasis in sub-saharan Africa. 3-alkylphenols are used as attractants in tsetse fly traps to reduce the spread of the disease. Here we present an inexpensive production method for 3-ethylphenol (3-EP) and 3-propylphenol (3-PP) by microbial fermentation of sugars. Heterologous expression in the yeast Saccharomyces cerevisiae of phosphopantetheinyltransferase-activated 6-methylsalicylic acid (6-MSA) synthase (MSAS) and 6-MSA decarboxylase converted acetyl-CoA as a priming unit via 6-MSA into 3-methylphenol (3-MP). We exploited the substrate promiscuity of MSAS to utilize propionyl-CoA and butyryl-CoA as alternative priming units and the substrate promiscuity of 6-MSA decarboxylase to produce 3-EP and 3-PP in yeast fermentations. Increasing the formation of propionyl-CoA by expression of a bacterial propionyl-CoA synthetase, feeding of propionate and blocking propionyl-CoA degradation led to the production of up to 12.5 mg/L 3-EP. Introduction of a heterologous ‘reverse ß-oxidation’ pathway provided enough butyryl-CoA for the production of 3-PP, reaching titers of up to 2.6 mg/L. As the concentrations of 3-alkylphenols are close to the range of the concentrations deployed in tsetse fly traps, the yeast broths might become promising and inexpensive sources for attractants, producible on site by rural communities in Africa.
Transcriptional basis for differential thermosensitivity of seedlings of various tomato genotypes
(2020)
Transcriptional reprograming after the exposure of plants to elevated temperatures is a hallmark of stress response which is required for the manifestation of thermotolerance. Central transcription factors regulate the stress survival and recovery mechanisms and many of the core responses controlled by these factors are well described. In turn, pathways and specific genes contributing to variations in the thermotolerance capacity even among closely related plant genotypes are not well defined. A seedling-based assay was developed to directly compare the growth and transcriptome response to heat stress in four tomato genotypes with contrasting thermotolerance. The conserved and the genotype-specific alterations of mRNA abundance in response to heat stress were monitored after exposure to three different temperatures. The transcripts of the majority of genes behave similarly in all genotypes, including the majority of heat stress transcription factors and heat shock proteins, but also genes involved in photosynthesis and mitochondrial ATP production. In turn, genes involved in hormone and RNA-based regulation, such as auxin- and ethylene-related genes, or transcription factors like HsfA6b, show a differential regulation that associates with the thermotolerance pattern. Our results provide an inventory of genes likely involved in core and genotype-dependent heat stress response mechanisms with putative role in thermotolerance in tomato seedlings.
The UN's sustainable development goals (SDGs), which aim to solve important economic, social, and environmental problems of humanity, are to be supported by education for sustainable development (ESD). Empirical studies on the success of the implementation of the SDGs in the field of education are still pending. For this reason, using the loss of global biodiversity as an example, this study examined the extent to which high school students, teacher trainees in biology, and biology bachelor students can identify the causes of the global biodiversity loss. A new questioning tool was developed and tested on 889 participants. In addition, the relationship between connection to nature and the personal assessment about biodiversity threats was examined. The factor analysis of the scale used showed that 11 out of 16 items were assigned to the intended factor. The comparison between high school students, teacher trainees in biology, and biology bachelor students showed no significant difference in overall assessment of the reasons for global biodiversity loss. When comparing the three risk levels in which the risk factors for biodiversity could be divided, across the three student groups, only minor differences were found. Therefore, a specific education of prospective teachers is necessary, as they have to pass on the competence as multipliers to their students. No significant difference could be found when examining the relationship between connection to nature and the overall scores of the assessment scale for the reasons of biodiversity loss. However, it was found that people who felt more connected to nature were more capable of assessing the main causes of risk for global biodiversity, while people who felt less connected to nature achieved better scores for the medium factors
Risk evaluations for agricultural chemicals are necessary to preserve healthy populations of honey bee colonies. Field studies on whole colonies are limited in behavioural research, while results from lab studies allow only restricted conclusions on whole colony impacts. Methods for automated long-term investigations of behaviours within comb cells, such as brood care, were hitherto missing. In the present study, we demonstrate an innovative video method that enables within-cell analysis in honey bee (Apis mellifera) observation hives to detect chronic sublethal neonicotinoid effects of clothianidin (1 and 10 ppb) and thiacloprid (200 ppb) on worker behaviour and development. In May and June, colonies which were fed 10 ppb clothianidin and 200 ppb thiacloprid in syrup over three weeks showed reduced feeding visits and duration throughout various larval development days (LDDs). On LDD 6 (capping day) total feeding duration did not differ between treatments. Behavioural adaptation was exhibited by nurses in the treatment groups in response to retarded larval development by increasing the overall feeding timespan. Using our machine learning algorithm, we demonstrate a novel method for detecting behaviours in an intact hive that can be applied in a versatile manner to conduct impact analyses of chemicals, pests and other stressors.
The transition from local to global patterns governs the differentiation of mouse blastocysts
(2020)
During mammalian blastocyst development, inner cell mass (ICM) cells differentiate into epiblast (Epi) or primitive endoderm (PrE). These two fates are characterized by the expression of the transcription factors NANOG and GATA6, respectively. Here, we investigate the spatio-temporal distribution of NANOG and GATA6 expressing cells in the ICM of the mouse blastocysts with quantitative three-dimensional single cell-based neighbourhood analyses. We define the cell neighbourhood by local features, which include the expression levels of both fate markers expressed in each cell and its neighbours, and the number of neighbouring cells. We further include the position of a cell relative to the centre of the ICM as a global positional feature. Our analyses reveal a local three-dimensional pattern that is already present in early blastocysts: 1) Cells expressing the highest NANOG levels are surrounded by approximately nine neighbours, while 2) cells expressing GATA6 cluster according to their GATA6 levels. This local pattern evolves into a global pattern in the ICM that starts to emerge in mid blastocysts. We show that FGF/MAPK signalling is involved in the three-dimensional distribution of the cells and, using a mutant background, we further show that the GATA6 neighbourhood is regulated by NANOG. Our quantitative study suggests that the three-dimensional cell neighbourhood plays a role in Epi and PrE precursor specification. Our results highlight the importance of analysing the three-dimensional cell neighbourhood while investigating cell fate decisions during early mouse embryonic development.
Wolves (Canis lupus) are currently showing a remarkable comeback in the highly frag-mented cultural landscapes of Germany. We here show that wolf numbers increasedexponentially between 2000 and 2015 with an annual increase of about 36%. Wedemonstrate that the first territories in each newly colonized region were establishedover long distances from the nearest known reproducing pack on active militarytraining areas (MTAs). We show that MTAs, rather than protected areas, served asstepping-stones for the recolonization of Germany facilitating subsequent spreadingof wolf territories in the surrounding landscape. We did not find any significant differ-ence between MTAs and protected areas with regard to habitat. One possible reasonfor the importance of MTAs may be their lower anthropogenic mortality rates com-pared to protected and other areas. To our knowledge, this is the first documented casewhere MTAs facilitate the recolonization of an endangered species across large areas.
Most mammals rely on the extraction of acoustic information from the environment in order to survive. However, the mechanisms that support sound representation in auditory neural networks involving sensory and association brain areas remain underexplored. In this study, we address the functional connectivity between an auditory region in frontal cortex (the frontal auditory field, FAF) and the auditory cortex (AC) in the bat Carollia perspicillata. The AC is a classic sensory area central for the processing of acoustic information. On the other hand, the FAF belongs to the frontal lobe, a brain region involved in the integration of sensory inputs, modulation of cognitive states, and in the coordination of behavioral outputs. The FAF-AC network was examined in terms of oscillatory coherence (local-field potentials, LFPs), and within an information theoretical framework linking FAF and AC spiking activity. We show that in the absence of acoustic stimulation, simultaneously recorded LFPs from FAF and AC are coherent in low frequencies (1–12 Hz). This “default” coupling was strongest in deep AC layers and was unaltered by acoustic stimulation. However, presenting auditory stimuli did trigger the emergence of coherent auditory-evoked gamma-band activity (>25 Hz) between the FAF and AC. In terms of spiking, our results suggest that FAF and AC engage in distinct coding strategies for representing artificial and natural sounds. Taken together, our findings shed light onto the neuronal coding strategies and functional coupling mechanisms that enable sound representation at the network level in the mammalian brain.
In recent environmental research, relational values (RVs) have emerged as a new group of values to explain environmental behavior. Although this new concept is attracting attention, empirical studies on the subject are still rare. On this basis, we have conducted three studies to analyze an existing measurement tool for RVs and compared the construct with the concept of connection to nature. In study 1, we confirmed convergent and discriminant validity of the RV scale by comparing it with the Two Factor Model of Environmental Values (2-MEV) model using a sample of n = 350 university students. Additionally, study 1 verified reliability using test–retest reliability on three different groups of students (n1 = 53; n2 = 37; n3 = 48). In study 2, principal component analyses were performed to examine the structure of RVs and to compare it to the concept of connection to nature by reusing the sample 350 university students from study 1. The results show that RVs and connection to nature are not fundamentally distinct constructs, but overlap. However, if the structure of the RV measurement is forced to a single factor, no perfect fit is found, making a multidimensional solution more likely. A third study was conducted to review the results from study 2 using confirmatory factor analysis on a new sample of 878 university and high school students. Study 3 confirmed RVs as a multidimensional construct with three factors: care, community, and connection. It also proved the overlap of the connection to nature and RV concepts to some extent.
Acetylcholine (ACh) is the major excitatory neurotransmitter in the insect central nervous system (CNS). However, besides the neuronal expression of ACh receptors (AChR), the existence of non-neuronal AChR in honeybees is plausible. The cholinergic system is a popular target of insecticides because the pharmacology of insect nicotinic acetylcholine receptors (nAChRs) differs substantially from their vertebrate counterparts. Neonicotinoids are agonists of the nAChR and are largely used in crop protection. In contrast to their relatively high safety for humans and livestock, neonicotinoids pose a threat to pollinating insects such as bees. In addition to its effects on behavior, it becomes increasingly evident that neonicotinoids affect developmental processes in bees that appear to be independent of neuronal AChRs. Brood food (royal jelly, worker jelly, or drone jelly) produced in the hypopharyngeal glands of nurse bees contains millimolar concentrations of ACh, which is required for proper larval development. Neonicotinoids reduce the secreted ACh-content in brood food, reduce hypopharyngeal gland size, and lead to developmental impairments within the colony. We assume that potential hazards of neonicotinoids on pollinating bees occur neuronally causing behavioral impairments on adult individuals, and non-neuronally causing developmental disturbances as well as destroying gland functioning.
Background: Developmental biology relies to a large extent on the observation and comparison of phenotypic traits through time using high resolution microscopes. In this context, transparent model organisms such as the zebrafish Danio rerio in which developing tissues and organs can be easily observed and imaged using fluorescent proteins have become very popular. One limiting factor however is the acquisition of a sufficient amount of data, in standardized and reproducible conditions, to allow robust quantitative analysis. One way to improve this is by developing mounting methods to increase the number of embryos that can be imaged simultaneously in near-to-identical orientation.
Results: Here we present an improved mounting method allowing semi-automated and high-content imaging of zebrafish embryos. It is based on a 3D-printed stamp which is used to create a 2D coordinate system of multiple μ-wells in an agarose cast. Each μ-well models a negative of the average zebrafish embryo morphology between 22 and 96 h-post-fertilization. Due to this standardized and reproducible arrangement, it is possible to define a custom well plate in the respective imaging software that allows for a semi-automated imaging process. Furthermore, the improvement in Z-orientation significantly reduces post-processing and improves comparability of volumetric data while reducing light exposure and thus photo-bleaching and photo-toxicity, and improving signal-to-noise ratio (SNR).
Conclusions: We present here a new method that allows to standardize and improve mounting and imaging of embryos. The 3D-printed stamp creates a 2D coordinate system of μ-wells in an agarose cast thus standardizing specimen mounting and allowing high-content imaging of up to 44 live or mounted zebrafish embryos simultaneously in a semi-automated, well-plate like manner on inverted confocal microscopes. In summary, image data quality and acquisition efficiency (amount of data per time) are significantly improved. The latter might also be crucial when using the services of a microscopy facility.