Biodiversität und Klima Forschungszentrum (BiK-F)
Refine
Year of publication
Document Type
- Article (270)
- Preprint (8)
- Part of Periodical (4)
- Book (3)
- Contribution to a Periodical (3)
- Doctoral Thesis (3)
- Conference Proceeding (1)
- Review (1)
Language
- English (279)
- German (11)
- Multiple languages (3)
Has Fulltext
- yes (293)
Is part of the Bibliography
- no (293)
Keywords
- climate change (9)
- Invasive species (7)
- Phylogeny (6)
- Biodiversity (5)
- Biogeography (5)
- phylogeny (5)
- taxonomy (5)
- Climate change (4)
- Ecological modelling (4)
- West Africa (4)
Institute
- Biodiversität und Klima Forschungszentrum (BiK-F) (293)
- Senckenbergische Naturforschende Gesellschaft (189)
- Institut für Ökologie, Evolution und Diversität (130)
- Biowissenschaften (113)
- Geowissenschaften (45)
- Medizin (13)
- Geographie (12)
- Institut für sozial-ökologische Forschung (ISOE) (7)
- Präsidium (5)
- LOEWE-Schwerpunkt für Integrative Pilzforschung (4)
- Zentrum für Interdisziplinäre Afrikaforschung (ZIAF) (3)
- Buchmann Institut für Molekulare Lebenswissenschaften (BMLS) (2)
- Geowissenschaften / Geographie (2)
- Gesellschaftswissenschaften (2)
- Informatik (2)
- Biochemie und Chemie (1)
- Exzellenzcluster Makromolekulare Komplexe (1)
- Frankfurt Institute for Advanced Studies (FIAS) (1)
- Kulturwissenschaften (1)
- Universitätsbibliothek (1)
Ceraceosorus bombacis is an early-diverging lineage of smut fungi and a pathogen of cotton trees (Bombax ceiba). To study the evolutionary genomics of smut fungi in comparison with other fungal and oomycete pathogens, the genome of C. bombacis was sequenced and comparative genomic analyses were performed. The genome of 26.09 Mb encodes for 8,024 proteins, of which 576 are putative-secreted effector proteins (PSEPs). Orthology analysis revealed 30 ortholog PSEPs among six Ustilaginomycotina genomes, the largest groups of which are lytic enzymes, such as aspartic peptidase and glycoside hydrolase. Positive selection analyses revealed the highest percentage of positively selected PSEPs in C. bombacis compared with other Ustilaginomycotina genomes. Metabolic pathway analyses revealed the absence of genes encoding for nitrite and nitrate reductase in the genome of the human skin pathogen Malassezia globosa, but these enzymes are present in the sequenced plant pathogens in smut fungi. Interestingly, these genes are also absent in cultivable oomycete animal pathogens, while nitrate reductase has been lost in cultivable oomycete plant pathogens. Similar patterns were also observed for obligate biotrophic and hemi-biotrophic fungal and oomycete pathogens. Furthermore, it was found that both fungal and oomycete animal pathogen genomes are lacking cutinases and pectinesterases. Overall, these findings highlight the parallel evolution of certain genomic traits, revealing potential common evolutionary trajectories among fungal and oomycete pathogens, shaping the pathogen genomes according to their lifestyle.
The use of parasites as biological tags for discrimination of fish stocks has become a commonly used approach in fisheries management. Metazoan parasite community analysis and anisakid nematode population genetics based on a mitochondrial cytochrome marker were applied in order to assess the usefulness of the two parasitological methods for stock discrimination of beaked redfish Sebastes mentella of three fishing grounds in the North East Atlantic. Multivariate, model-based approaches demonstrated that the metazoan parasite fauna of beaked redfish from East Greenland differed from Tampen, northern North Sea, and Bear Island, Barents Sea. A joint model (latent variable model) was used to estimate the effects of covariates on parasite species and identified four parasite species as main source of differences among fishing grounds; namely Chondracanthus nodosus, Anisakis simplex s.s., Hysterothylacium aduncum, and Bothriocephalus scorpii. Due to its high abundance and differences between fishing grounds, Anisakis simplex s.s. was considered as a major biological tag for host stock differentiation. Whilst the sole examination of Anisakis simplex s.s. on a population genetic level is only of limited use, anisakid nematodes (in particular, A. simplex s.s.) can serve as biological tags on a parasite community level. This study confirmed the use of multivariate analyses as a tool to evaluate parasite infra-communities and to identify parasite species that might serve as biological tags. The present study suggests that S. mentella in the northern North Sea and Barents Sea is not sub-structured.
Deciduous plants avoid the costs of maintaining leaves in the unfavourable season, but carry the costs of constructing new leaves every year. Deciduousness is therefore expected in ecological situations with pronounced seasonality and low costs of leaf construction. In our study system, a seasonally dry tropical savanna, many trees are deciduous, suggesting that leaf construction costs must be low. Previous studies have, however, shown that nitrogen is limiting in this system, suggesting that leaf construction costs are high. Here we examine this conundrum using a time series of soil moisture availability, leaf phenology and nitrogen distribution in the tree canopy to illustrate how trees resorb nitrogen before leaf abscission and use stored reserves of nitrogen and carbon to construct new leaves at the onset of the growing season. Our results show that trees deployed leaves shortly before and in anticipation of the first rains with its associated pulse of nitrogen mineralisation. Our results also show that trees rapidly constructed a full canopy of leaves within two weeks of the first rains. We detected an increase in leaf nitrogen content that corresponded with the first rains and with the movement of nitrogen to more distal branches, suggesting that stored nitrogen reserves are used to construct leaves. Furthermore the stable carbon isotope ratios (δ13C) of these leaves suggest the use of stored carbon for leaf construction. Our findings suggest that the early deployment of leaves using stored nitrogen and carbon reserves is a strategy that is integrally linked with the onset of the first rains. This strategy may confer a competitive advantage over species that deploy leaves at or after the onset of the rains.
The Asian tiger mosquito Aedes albopictus, native to South East Asia, is listed as one of the worst invasive vector species worldwide. In Europe the species is currently restricted to Southern Europe, but due to the ongoing climate change, Ae. albopictus is expected to expand its potential range further northwards. In addition to modelling the habitat suitability for Ae. albopictus under current and future climatic conditions in Europe by means of the maximum entropy approach, we here focused on the drivers of the habitat suitability prediction. We explored the most limiting factors for Aedes albopictus in Europe under current and future climatic conditions, a method which has been neglected in species distribution modelling so far. Ae. albopictus is one of the best-studied mosquito species, which allowed us to evaluate the applied Maxent approach for most limiting factor mapping. We identified three key limiting factors for Ae. albopictus in Europe under current climatic conditions: winter temperature in Eastern Europe, summer temperature in Southern Europe. Model findings were in good accordance with commonly known establishment thresholds in Europe based on climate chamber experiments and derived from the geographical distribution of the species. Under future climatic conditions low winter temperature were modelled to remain the most limiting factor in Eastern Europe, whereas in Central Europe annual mean temperature and summer temperatures were modelled to be replaced by summer precipitation, respectively, as most limiting factors. Changes in the climatic conditions in terms of the identified key limiting factors will be of great relevance regarding the invasive potential of the Ae. albopictus. Thus, our results may help to understand the key drivers of the suggested range expansion under climate change and may help to improve monitoring programmes. The applied approach of investigating limiting factors has proven to yield valuable results and may also provide valuable insights into the drivers of the prediction of current and future distribution of other species. This might be particularly interesting for other vector species that are of increasing public health concerns.
The caddisfly subfamily Drusinae BANKS comprises roughly 100 species inhabiting mountain ranges in Europe, Asia Minor and the Caucasus. A 3-gene phylogeny of the subfamily previously identified three major clades that were corroborated by larval morphology and feeding ecologies: scraping grazers, omnivorous shredders and filtering carnivores. Larvae of filtering carnivores exhibit unique head capsule complexities, unknown from other caddisfly larvae. Here we assess the species-level relationships within filtering carnivores, hypothesizing that head capsule complexity is derived from simple shapes observed in the other feeding groups. We summarize the current systematics and taxonomy of the group, clarify the systematic position of Cryptothrix nebulicola, and present a larval key to filtering carnivorous Drusinae. We infer relationships of all known filtering carnivorous Drusinae and 34 additional Drusinae species using Bayesian species tree analysis and concatenated Bayesian phylogenetic analysis of 3805bp of sequence data from six gene regions (mtCOI5-P, mtCOI3-P, 16S mrDNA, CADH, WG, 28S nrDNA), morphological cladistics from 308 characters, and a total evidence analysis. All analyses support monophyly of the three feeding ecology groups but fail to fully resolve internal relationships. Within filtering carnivores, variation in head setation and frontoclypeus structure may be associated with progressive niche adaptation, with less complex species recovered at a basal position. We propose that diversification of complex setation and frontoclypeus shape represents a recent evolutionary development, hypothetically enforcing speciation and niche specificity within filtering carnivorous Drusinae.
The genus Thlaspi has been variously subdivided since its description by Linnaeus in 1753, but due to similarities in fruit shape several segregates have still not gained broad recognition, despite the fact that they are not directly related to Thlaspi. This applies especially to segregates now considered to belong to the tribe Coluteocarpeae, which includes several well-studied taxa, e.g., Noccaea caerulescens (syn. Thlaspi caerulescens), and the widespread Microthlaspi perfoliatum (syn. Thlaspi perfoliatum). The taxonomy of this tribe is still debated, as a series of detailed monographs on Coluteocarpeae was not published in English and a lack of phylogenetic resolution within this tribe was found in previous studies. The current study presents detailed phylogenetic investigations and a critical review of morphological features, with focus on taxa previously placed in Microthlaspi. Based on one nuclear (ITS) and two chloroplast (matK, trnL-F) loci, four strongly supported major groups were recovered among the Coluteocarpeae genera included, corresponding to Ihsanalshehbazia gen. nov., Friedrichkarlmeyeria gen. nov., Microthlaspi s.str., and Noccaea s.l. In addition, two new species of Microthlaspi, M. sylvarum-cedri sp. nov. and M. mediterraneo-orientale sp. nov., were discovered, which are well supported by both morphological and molecular data. Furthermore, M. erraticum comb. nov. (diploid) and M. perfoliatum s.str. (polyploid) were shown to be distinct species, phylogenetically widely separate, but with some overlap in several morphological characters. Detailed descriptions, notes on taxonomy, geographical distribution, and line drawings for the new species and each species previously included in Microthlaspi are provided. In addition, the current taxonomic state of the tribe Coluteocarpeae is briefly discussed and it is concluded that while several annual taxa are clearly distinct from Noccaea, many perennial taxa, after thorough phylogenetic and morphological investigations, may have to be merged with this genus.
Abstract:
Snakebite is an important medical emergency in rural Nepal. Correct identification of the biting species is crucial for clinicians to choose appropriate treatment and anticipate complications. This is particularly important for neurotoxic envenoming which, depending on the snake species involved, may not respond to available antivenoms. Adequate species identification tools are lacking. This study used a combination of morphological and molecular approaches (PCR-aided DNA sequencing from swabs of bite sites) to determine the contribution of venomous and non-venomous species to the snakebite burden in southern Nepal. Out of 749 patients admitted with a history of snakebite to one of three study centres, the biting species could be identified in 194 (25.9%). Out of these, 87 had been bitten by a venomous snake, most commonly the Indian spectacled cobra (Naja naja; n = 42) and the common krait (Bungarus caeruleus; n = 22). When both morphological identification and PCR/sequencing results were available, a 100% agreement was noted. The probability of a positive PCR result was significantly lower among patients who had used inadequate “first aid” measures (e.g. tourniquets or local application of remedies). This study is the first to report the use of forensic genetics methods for snake species identification in a prospective clinical study. If high diagnostic accuracy is confirmed in larger cohorts, this method will be a very useful reference diagnostic tool for epidemiological investigations and clinical studies.
Author Summary:
Snakebite is an important medical problem in sub-tropical and tropical regions, including Nepal where tens of thousands of people are bitten every year. Snakebite can result in life-threatening envenoming, and correct identification of the biting species is crucial for care providers to choose appropriate treatment and anticipate complications. This paper explores a number of methods, including molecular techniques, to assist care providers in identifying the species responsible for bites in rural Nepal. Out of 749 patients with a history of snakebite, the biting species could be identified in 194 (25.9%). Out of these, 87 had been bitten by a venomous snake, most commonly cobras (n = 42) and kraits (n = 22). This study is the first to report the use of molecular techniques for snake species identification. The diagnostic accuracy of this method appears high but needs to be confirmed in larger studies.
Background: The impact of climate change on public health may occur through a number of main pathways including increased temperature, ground-level ozone levels and ultra-violet radiation, which have a range of consequences for human health. One strategy for adaptation to the predicted effects of climate change on health that has been proposed, is to ‘green’ urban areas, essentially by increasing the abundance and cover of vegetation. This protocol is for an update of a systematic review which aimed to address the question: How effective is ‘greening’ of urban areas in reducing human exposure to ground-level ozone concentrations, UV exposure and the ‘urban heat island effect’?
Methods: A sensitive search of multiple databases and relevant journals for relevant published articles will be conducted. A search for relevant unpublished articles will be undertaken through an internet search and of websites of relevant organisations. Inclusion criteria will be applied at title, abstract and full-text. Repeatability checks of this screening process will be undertaken. Articles included at full-text will be critically appraised using a standardised checklist. A repeatability check will be made of this process. Pre-defined data items will be extracted from included articles. If appropriate, quantitative synthesis will be undertaken through meta-analysis and/or a narrative synthesis will be undertaken.
Network graphs have become a popular tool to represent complex systems composed of many interacting subunits; especially in neuroscience, network graphs are increasingly used to represent and analyze functional interactions between multiple neural sources. Interactions are often reconstructed using pairwise bivariate analyses, overlooking the multivariate nature of interactions: it is neglected that investigating the effect of one source on a target necessitates to take all other sources as potential nuisance variables into account; also combinations of sources may act jointly on a given target. Bivariate analyses produce networks that may contain spurious interactions, which reduce the interpretability of the network and its graph metrics. A truly multivariate reconstruction, however, is computationally intractable because of the combinatorial explosion in the number of potential interactions. Thus, we have to resort to approximative methods to handle the intractability of multivariate interaction reconstruction, and thereby enable the use of networks in neuroscience. Here, we suggest such an approximative approach in the form of an algorithm that extends fast bivariate interaction reconstruction by identifying potentially spurious interactions post-hoc: the algorithm uses interaction delays reconstructed for directed bivariate interactions to tag potentially spurious edges on the basis of their timing signatures in the context of the surrounding network. Such tagged interactions may then be pruned, which produces a statistically conservative network approximation that is guaranteed to contain non-spurious interactions only. We describe the algorithm and present a reference implementation in MATLAB to test the algorithm’s performance on simulated networks as well as networks derived from magnetoencephalographic data. We discuss the algorithm in relation to other approximative multivariate methods and highlight suitable application scenarios. Our approach is a tractable and data-efficient way of reconstructing approximative networks of multivariate interactions. It is preferable if available data are limited or if fully multivariate approaches are computationally infeasible.
The bug Gyaclavator kohlsi Wappler, Guilbert, Wedmann et Labandeira, gen. et sp. nov., represents a new extinct genus of lace bugs (Insecta: Heteroptera: Tingidae) occurring in latest early Eocene deposits of the Green River Formation, from the southern Piceance Basin of Northwestern Colorado, in North America. Gyaclavator can be placed within the Tingidae with certainty, perhaps it is sistergroup to Cantacaderinae. If it belongs to Cantacaderinae, it is the first fossil record of this group for North America. Gyaclavator has unique, conspicuous antennae bearing a specialized, highly dilated distiflagellomere, likely important for intra- or intersex reproductive competition and attraction. This character parallels similar antennae in leaf-footed bugs (Coreidae), and probably is associated with a behavioral convergence as well.
An individual's choices are shaped by its experience, a fundamental property of behavior important to understanding complex processes. Learning and memory are observed across many taxa and can drive behaviors, including foraging behavior. To explore the conditions under which memory provides an advantage, we present a continuous-space, continuous-time model of animal movement that incorporates learning and memory. Using simulation models, we evaluate the benefit memory provides across several types of landscapes with variable-quality resources and compare the memory model within a nested hierarchy of simpler models (behavioral switching and random walk). We find that memory almost always leads to improved foraging success, but that this effect is most marked in landscapes containing sparse, contiguous patches of high-value resources that regenerate relatively fast and are located in an otherwise devoid landscape. In these cases, there is a large payoff for finding a resource patch, due to size, value, or locational difficulty. While memory-informed search is difficult to differentiate from other factors using solely movement data, our results suggest that disproportionate spatial use of higher value areas, higher consumption rates, and consumption variability all point to memory influencing the movement direction of animals in certain ecosystems.
In the last decades, natural products from lichens have gained more interest for pharmaceutical application due to the broad range of their biological activity. However, isolation of the compounds of interest directly from the lichen is neither feasible nor sustainable due to slow growth of many lichens. In order to develop a pipeline for heterologous expression of lichen biosynthesis gene clusters and thus the sustainable production of their bioactive compounds we have identified and characterized the phosphopantheteinyl transferase (PPTase) EppA from the lichen Evernia prunastri. The Sfp-type PPTase EppA was functionally characterized through heterologous expression in E. coli using the production of the blue pigment indigoidine as readout and by complementation of a lys5 deletion in S. cerevisiae.
In most habitats, vegetation provides the main structure of the environment. This complexity can facilitate biodiversity and ecosystem services. Therefore, measures of vegetation structure can serve as indicators in ecosystem management. However, many structural measures are laborious and require expert knowledge. Here, we used consistent and convenient measures to assess vegetation structure over an exceptionally broad elevation gradient of 866–4550m above sea level at Mount Kilimanjaro, Tanzania. Additionally, we compared (human)-modified habitats, including maize fields, traditionally managed home gardens, grasslands, commercial coffee farms and logged and burned forests with natural habitats along this elevation gradient. We distinguished vertical and horizontal vegetation structure to account for habitat complexity and heterogeneity. Vertical vegetation structure (assessed as number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover) displayed a unimodal elevation pattern, peaking at intermediate elevations in montane forests, whereas horizontal structure (assessed as coefficient of variation of number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover) was lowest at intermediate altitudes. Overall, vertical structure was consistently lower in modified than in natural habitat types, whereas horizontal structure was inconsistently different in modified than in natural habitat types, depending on the specific structural measure and habitat type. Our study shows how vertical and horizontal vegetation structure can be assessed efficiently in various habitat types in tropical mountain regions, and we suggest to apply this as a tool for informing future biodiversity and ecosystem service studies.
Although there is an increasing need for data in ecological studies, many datasets are still lost or not sufficiently visible due to a lack of appropriate data archives. With the West African Data and Metadata Repository, we present a secure long-term archive for a data-poor region allowing detailed documentation by metadata following the EML standard and giving data holders the opportunity to define levels of data access and conditions of use. This article gives an overview of structure, functions and content. The repository is online at the URL http://westafricandata.senckenberg.de.
Background: The invasive eel parasite Anguillicoloides crassus (syn. Anguillicola crassus) is considered one of the major causes for the decline of the European eel (Anguilla anguilla) panmictic population. It impairs the swim bladder function and reduces swimming performance of its host. The life cycle of this parasite involves different intermediate and paratenic hosts. Despite an efficient immune system of the paratenic fish hosts acting against infections with A. crassus, levels of parasitized eels remain high in European river systems. Recently, the round goby Neogobius melanostomus (Gobiidae) has become dominant in many rivers in Europe and is still spreading at a rapid pace. This highly invasive species might potentially act as an important, so far neglected paratenic fish host for A. crassus.
Methods: Based on own observations and earlier single sightings of A. crassus in N. melanostomus, 60 fresh individuals of N. melanostomus were caught in the Rhine River and examined to assess the infection levels with metazoan parasites, especially A. crassus. Glycerin preparations were used for parasite identification.
Results: The parasite most frequently found in N. melanostomus was the acanthocephalan Pomphorhynchus sp. (subadult stage) which occurred mainly encysted in the mesenteries and liver. Every third gobiid (P = 31.7%) was infected by A. crassus larvae (L3) which exclusively occurred inside the acanthocephalan cysts. No intact or degenerated larvae of A. crassus were detected elsewhere in the goby, neither in the body cavity and mesenteries nor in other organs. Affected cysts contained the acanthocephalan larvae and 1-12 (mI =3) living A. crassus larvae. Additionally, encysted larvae of the nematode Raphidascaris acus were detected in the gobies, but only in the body cavity and not inside the acanthocephalan cysts.
Conclusions: Based on our observations, we suggest that A. crassus might actively bypass the immune response of N. melanostomus by invading the cysts of acanthocephalan parasites of the genus Pomphorhynchus using them as "Trojan horses". Providing that eels prey on the highly abundant round goby and that the latter transfers viable infective larvae of A. crassus, the new paratenic host might have a strong impact on the epidemiology of A. crassus.
Stechmücken (Dipteren: Culicidae) sind weltweit mit über 3500 Arten und mit Ausnahme der arktischen Regionen ubiquitär vertreten. Die medizinische Relevanz dieser Tiergruppe, begründet durch die hämatophage Lebensweise der Weibchen, erschloss sich bereits Ende des 19. Jh. und hat bis heute Bestand. Jedes Jahr sterben rund 600.000 Menschen an den Folgen der Malaria und fast 100 Mio. Menschen infizieren sich mit dem Denguefieber. Zwar beziehen sich diese Zahlen fast ausschließlich auf die Entwicklungsländer, aber im Zuge des Klimawandels und des immer stärkeren Welthandels kommt es auch in Europa und den USA immer wieder zu Ausbrüchen vorher nicht relevanter Krankheiten. So hat sich das West-Nil- Virus seit 1999 in Nordamerika rasant verbreitet. Im Jahr 2013 gab es dort rund 2500 Fälle, von denen 119 zum Tod führten. In Europa traten hingegen Krankheiten wie das Chikungunyafieber (Italien 2007) oder das Denguefieber (Frankreich 2010/2013) auf. Die Gründe für diese Ausbrüche sind vor allem in der Einschleppung neuer Vektorspezies und Krankheitserreger sowie in den veränderten Wirtspräferenzen einheimischer Stechmückenarten zu suchen. Das Wissen um das Vektorpotential der in Deutschland heimischen Stechmücken konnte vor allem durch die seit 2009 initiierten Monitoring-Programme stetig erweitert werden. Auch die Veränderung der heimischen Fauna durch invasive Arten wie Ochlerotatus japonicus japonicus oder Aedes albopictus wird intensiv erforscht. Dennoch ist hinsichtlich der Biologie, Ökologie sowie Genetik vieler Arten noch immer wenig bekannt.
Die vorliegende Dissertation, welche auf Basis von vier (ISI-) Einzelpublikationen kumulativ angefertigt wurde, beschäftigte sich mit der Analyse der genetischen Variabilität sowie der Zoogeographie der untersuchten Arten und der Etablierung einer schnellen und kostengünstigen Methode zur Artdiagnostik. Besonderes Augenmerk wurde bei den Analysen auf die beiden heimischen Arten Culex pipiens und Culex torrentium sowie die invasive Art Ochlerotatus japonicus japonicus gelegt. Ziel war es, die noch bestehenden Wissenslücken zu füllen, um zukünftige Monitoring-Programme besser koordinieren sowie Analysen zur Vektorkompetenz und Genetik dieser Arten gezielter durchführen zu können.
Es konnte gezeigt werden, dass Cx. pipiens und Cx. torrentium deutliche Unterschiede in ihren Populationsstrukturen aufwiesen welche auf verschiedene evolutive Prozesse hindeuten. Die geringere genetische Variabilität in Cx. pipiens lässt auf positive Selektion durch z.B. Insektizidresistenz im Zuge durchgeführter Bekämpfungsmaßnahmen oder die Infektion mit Wolbachien schließen. Die analysierte Populationsstruktur von Cx. torrentium spricht hingegen für eine geringe Ausbreitung, wodurch der genetische Austausch reduziert wurde und so die untersuchten Populationen genetisch stärker voneinander abwichen. Des Weiteren ließen die Analysen des Cytochrom c Oxidase Untereinheit 1-Fragmentes (cox1) Rückschlüsse auf die Zoogeographie dieser Arten in Deutschland zu - wobei beide Arten über das Untersuchungsgebiet verteilt waren, Cx. torrentium jedoch in den neuen Bundesländern weniger häufig nachgewiesen wurde als in den alten und eine geringere gefangene Individuenzahl aufwies. Basierend auf der ökologischen Nischenmodellierung konnten potentiell neue Verbreitungsgebiete für die Art Ochlerotatus japonicus japonicus identifiziert werden. Als klimatisch besonders günstig zeigten sich dabei Südhessen, das Saarland sowie nördliche Teile Nordrhein-Westfalens. Mit Hilfe der etablierten Methode der direct-PCR wird in Zukunft eine schnellere und kostengünstigere Identifizierung von Stechmücken erfolgen können, welche aufgrund bestimmungsrelevanter Merkmale nicht mehr morphologisch zu identifizieren sind.
Um das Wissen über die Stechmücken in Deutschland fortlaufend zu intensivieren, ist sowohl das Weiterführen der Monitoring-Programme als auch die molekularbiologische Aufarbeitung der Proben nötig. Durch die Anwendung neuer Techniken und weiterer molekularer Marker wird es möglich sein, weitere Krankheitserreger sowie genetische Besonderheiten der heimischen Stechmückenfauna nachzuweisen. Aber auch die Überwachung invasiver Stechmückenarten durch die Modellierung potentieller Verbreitungsgebiete und die Anwendung molekularbiologischer Analysemethoden zum Detektieren der Arten und möglicher Krankheitserreger wird ein wichtiger Bestandteil der weiteren Forschung sein.
Since few decades there is a broad debate about the so called ecological crisis. The debate had its highlight at the Rio-Conference in 1992. This conference was also the starting point for a wide range of political efforts concerned with a broad spectrum of biodiversity issues. Insofar, the term ‘biodiversity’ is not one of the natural sciences, but one which is inherently connected with questions of good human life. This article argues that the question for the good life predominantly fulfills a heuristic function and is to be answered in light of certain societal relations to nature. Furthermore, in light of these societal relations to nature it is argued for a virtue ethical approach with respect to the individual good life, whereas concerning the scale of societal aspects transdisciplinarity is identified as the appropriate research mode, which addresses both societal and scientific issues.
Background: Despite its largely mountainous terrain for which this Himalayan country is a popular tourist destination, Nepal is now endemic for five major vector-borne diseases (VBDs), namely malaria, lymphatic filariasis, Japanese encephalitis, visceral leishmaniasis and dengue fever. There is increasing evidence about the impacts of climate change on VBDs especially in tropical highlands and temperate regions. Our aim is to explore whether the observed spatiotemporal distributions of VBDs in Nepal can be related to climate change.
Methodology: A systematic literature search was performed and summarized information on climate change and the spatiotemporal distribution of VBDs in Nepal from the published literature until December 2014 following providing items for systematic review and meta-analysis (PRISMA) guidelines.
Principal findings: We found 12 studies that analysed the trend of climatic data and are relevant for the study of VBDs, 38 studies that dealt with the spatial and temporal distribution of disease vectors and disease transmission. Among 38 studies, only eight studies assessed the association of VBDs with climatic variables. Our review highlights a pronounced warming in the mountains and an expansion of autochthonous cases of VBDs to non-endemic areas including mountain regions (i.e., at least 2,000 m above sea level). Furthermore, significant relationships between climatic variables and VBDs and their vectors are found in short-term studies.
Conclusion: Taking into account the weak health care systems and difficult geographic terrain of Nepal, increasing trade and movements of people, a lack of vector control interventions, observed relationships between climatic variables and VBDs and their vectors and the establishment of relevant disease vectors already at least 2,000 m above sea level, we conclude that climate change can intensify the risk of VBD epidemics in the mountain regions of Nepal if other non-climatic drivers of VBDs remain constant.
Australia has experienced dramatic declines and extinctions of its native rodent species over the last 200 years, particularly in southern Australia. In the tropical savanna of northern Australia significant declines have occurred only in recent decades. The later onset of these declines suggests that the causes may differ from earlier declines in the south. We examine potential regional effects (northern versus southern Australia) on biological and ecological correlates of range decline in Australian rodents. We demonstrate that rodent declines have been greater in the south than in the tropical north, are strongly influenced by phylogeny, and are consistently greater for species inhabiting relatively open or sparsely vegetated habitat. Unlike in marsupials, where some species have much larger body size than rodents, body mass was not an important predictor of decline in rodents. All Australian rodent species are within the prey-size range of cats (throughout the continent) and red foxes (in the south). Contrary to the hypothesis that mammal declines are related directly to ecosystem productivity (annual rainfall), our results are consistent with the hypothesis that disturbances such as fire and grazing, which occur in non-rainforest habitats and remove cover used by rodents for shelter, nesting and foraging, increase predation risk. We agree with calls to introduce conservation management that limits the size and intensity of fires, increases fire patchiness and reduces grazing impacts at ecological scales appropriate for rodents. Controlling feral predators, even creating predator-free reserves in relatively sparsely-vegetated habitats, is urgently required to ensure the survival of rodent species, particularly in northern Australia where declines are not yet as severe as those in the south.
Genetic signatures of adaptation revealed from transcriptome sequencing of Arctic and red foxes
(2015)
Background: The genus Vulpes (true foxes) comprises numerous species that inhabit a wide range of habitats and climatic conditions, including one species, the Arctic fox (Vulpes lagopus) which is adapted to the arctic region. A close relative to the Arctic fox, the red fox (Vulpes vulpes), occurs in subarctic to subtropical habitats. To study the genetic basis of their adaptations to different environments, transcriptome sequences from two Arctic foxes and one red fox individual were generated and analyzed for signatures of positive selection. In addition, the data allowed for a phylogenetic analysis and divergence time estimate between the two fox species.
Results: The de novo assembly of reads resulted in more than 160,000 contigs/transcripts per individual. Approximately 17,000 homologous genes were identified using human and the non-redundant databases. Positive selection analyses revealed several genes involved in various metabolic and molecular processes such as energy metabolism, cardiac gene regulation, apoptosis and blood coagulation to be under positive selection in foxes. Branch site tests identified four genes to be under positive selection in the Arctic fox transcriptome, two of which are fat metabolism genes. In the red fox transcriptome eight genes are under positive selection, including molecular process genes, notably genes involved in ATP metabolism. Analysis of the three transcriptomes and five Sanger re-sequenced genes in additional individuals identified a lower genetic variability within Arctic foxes compared to red foxes, which is consistent with distribution range differences and demographic responses to past climatic fluctuations. A phylogenomic analysis estimated that the Arctic and red fox lineages diverged about three million years ago.
Conclusions: Transcriptome data are an economic way to generate genomic resources for evolutionary studies. Despite not representing an entire genome, this transcriptome analysis identified numerous genes that are relevant to arctic adaptation in foxes. Similar to polar bears, fat metabolism seems to play a central role in adaptation of Arctic foxes to the cold climate, as has been identified in the polar bear, another arctic specialist.