Evolutionary dynamics of transposable elements in bdelloid rotifers.
Evolutionary dynamics of transposable elements in bdelloid rotifers.
复制标题
蛭形轮虫转座因子的进化动力学。
DOI：
10.7554/elife.63194
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发表时间：
2021-02-05
期刊：
影响因子：
7.7
通讯作者：
Barraclough TG
中科院分区：
文献类型：
--
作者：
Nowell RW;Wilson CG;Almeida P;Schiffer PH;Fontaneto D;Becks L;Rodriguez F;Arkhipova IR;Barraclough TG
转座因子是一种自私的基因组寄生虫，其自主传播的能力是通过其宿主的有性繁殖来促进的。如果宿主变成专性无性，TE频率和动态预计将发生显着变化，但长期结果尚不清楚。在这里，我们测试目前的理论使用全基因组序列数据从8种蛭形轮虫，一类无脊椎动物，其中男性是迄今为止未知的。与预期相反，我们在蛭形虫基因组中发现了各种活跃的TE，其总体频率在有性物种中所见的范围内。我们没有发现任何证据表明，TE是通过隐蔽重组或不寻常的DNA修复机制的限制。相反，我们发现TE含量在蛭形类中相对缓慢地演变，并且参与RNAi介导的TE抑制的基因家族经历了显著的扩展，这可能减轻活性TE的有害影响并补偿长期无性的后果。
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.