PT  - JOURNAL ARTICLE
AU  - Reuben W. Nowell
AU  - Christopher G. Wilson
AU  - Pedro Almeida
AU  - Philipp H. Schiffer
AU  - Diego Fontaneto
AU  - Lutz Becks
AU  - Fernando Rodriguez
AU  - Irina R. Arkhipova
AU  - Timothy G. Barraclough
TI  - Evolutionary dynamics of transposable elements in bdelloid rotifers
AID  - 10.1101/2020.09.15.297952
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.09.15.297952
4099  - http://biorxiv.org/content/early/2020/09/16/2020.09.15.297952.1.short
4100  - http://biorxiv.org/content/early/2020/09/16/2020.09.15.297952.1.full
AB  - Transposable elements (TEs) are selfish genomic parasites whose ability to spread autonomously is facilitated by sexual reproduction in their hosts. If hosts become obligately asexual, TE frequencies and dynamics are predicted to change dramatically, but the long-term outcome is unclear. Here, we test current theory using whole-genome sequence data from eight species of bdelloid rotifers, a class of invertebrates where males are thus far unknown. Contrary to expectations, we find a diverse range of active TEs in bdelloid genomes, at an overall frequency within the range seen in sexual species. We find no evidence that TEs are spread by cryptic recombination or restrained by unusual DNA repair mechanisms, but we report that bdelloids share a large and unusual expansion of genes involved in RNAi-mediated TE suppression. This suggests that enhanced cellular defence mechanisms might mitigate the deleterious effects of active TEs and compensate for the consequences of long-term asexuality.Competing Interest StatementThe authors have declared no competing interest.