RT Journal Article
SR Electronic
T1 Genomic features of asexual animals
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 497495
DO 10.1101/497495
A1 Kamil S. Jaron
A1 Jens Bast
A1 Reuben W. Nowell
A1 T. Rhyker Ranallo-Benavidez
A1 Marc Robinson-Rechavi
A1 Tanja Schwander
YR 2019
UL http://biorxiv.org/content/early/2019/11/27/497495.abstract
AB Evolution under asexuality is predicted to impact genomes in numerous ways, but empirical evidence remains unclear. Case studies of individual asexual animals have reported peculiar genomic features which were suggested to be caused by asexuality, including high heterozygosity, a high abundance of horizontally acquired genes, a low transposable element load, or the presence of palindromes. We systematically characterized these genomic features in published genomes of 26 asexual animals representing at least 18 independent transitions to asexuality. Surprisingly, not a single feature is systematically replicated across a majority of these transitions, suggesting that no genomic feature is characteristic of asexuality and that previously reported patterns were lineage specific rather than caused by asexuality. We found that only asexuals of hybrid origin were characterized by high heterozygosity levels. Asexuals that were not of hybrid origin appeared to be largely homozygous, independently of the cellular mechanism underlying asexuality. Overall, despite the importance of recombination rate variation for the evolution of sexual animal genomes, the genome-wide absence of recombination does not appear to have had the dramatic effects which are expected from classical theoretical models. The reasons for this are probably a combination of lineage-specific patterns, impact of the origin of asexuality, and a survivorship bias of asexual lineages.