PT  - JOURNAL ARTICLE
AU  - Kamil S. Jaron
AU  - Jens Bast
AU  - Reuben W. Nowell
AU  - T. Rhyker Ranallo-Benavidez
AU  - Marc Robinson-Rechavi
AU  - Tanja Schwander
TI  - Genomic features of asexual animals
AID  - 10.1101/497495
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 497495
4099  - http://biorxiv.org/content/early/2019/11/27/497495.short
4100  - http://biorxiv.org/content/early/2019/11/27/497495.full
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.