Evolutionary dynamics of transposable elements in bdelloid rotifers

Citation

Nowell RW, Wilson CG, Almeida P, Schiffer PH, Fontaneto D, Becks L, Rodriguez F, Arkhipova IR & Barraclough TG (2021) Evolutionary dynamics of transposable elements in bdelloid rotifers. eLife, 10, Art. No.: e63194. https://doi.org/10.7554/elife.63194

Abstract
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 in which males are thus far unknown. Contrary to expectations, we find a variety 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. Instead, we find that that TE content evolves relatively slowly in bdelloids and that gene families involved in RNAi-mediated TE suppression have undergone significant expansion, which might mitigate the deleterious effects of active TEs and compensate for the consequences of long-term asexuality.

Keywords
General Immunology and Microbiology; General Biochemistry, Genetics and Molecular Biology; General Medicine; General Neuroscience

Journal
eLife: Volume 10

People

Dr Reuben Nowell

Lecturer in Animal Evolutionary Biology, Biological and Environmental Sciences