TY  - JOUR
A1  - Sharma, Rahul
A1  - Mishra, Bagdevi
A1  - Runge, Fabian
A1  - Thines, Marco
T1  - Gene loss rather than gene gain is associated with a host jump from monocots to dicots in the smut fungus Melanopsichium pennsylvanicum
T2  - Genome biology and evolution
N2  - Smut fungi are well-suited to investigate the ecology and evolution of plant pathogens, as they are strictly biotrophic, yet cultivable on media. Here we report the genome sequence of Melanopsichium pennsylvanicum, closely related to Ustilago maydis and other Poaceae-infecting smuts, but parasitic to a dicot plant. To explore the evolutionary patterns resulting from host adaptation after this huge host jump, the genome of M. pennsylvanicum was sequenced and compared to the genomes of Ustilago maydis, Sporisorium reilianum, and Ustilago hordei. While all four genomes had a similar completeness in CEGMA analyses, gene absence was highest in M. pennsylvanicum, and most pronounced in putative secreted proteins, which are often considered as effector candidates. In contrast, the amount of private genes was similar among the species, highlighting that gene loss rather than gene gain is the hallmark of adaptation after the host jump to the dicot host. Our analyses revealed a trend of putative effectors to be next to another putative effector, but the majority of these are not in clusters and thus the focus on pathogenicity clusters might not be appropriate for all smut genomes. Positive selection studies revealed that M. pennsylvanicum has the highest number and proportion of genes under positive selection. In general, putative effectors showed a higher proportion of positively selected genes than non-effector candidates. The 248 putative secreted effectors found in all four smut genomes might constitute a core set needed for pathogenicity, while those 92 that are found in all grass-parasitic smuts, but have no ortholog in M. pennsylvanicum might constitute a set of effectors important for successful colonization of grass hosts.
KW  - Comparative Genomics
KW  - Effector Genes
KW  - Evolutionary Biology
KW  - Genome Assembly
KW  - Host Jump
KW  - Positive Selection
KW  - Smut Fungi
Y1  - 2014
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/34203
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-342038
N1  - © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com
VL  - 6
IS  - 8
SP  - 2034
EP  - 2049
PB  - Oxford Univ. Press
CY  - Oxford
ER  -