Balancing selection maintains hyper-divergent haplotypes in Caenorhabditis elegans.
Balancing selection maintains hyper-divergent haplotypes in Caenorhabditis elegans.
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DOI：
10.1038/s41559-021-01435-x
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发表时间：
2021-06
影响因子：
16.8
通讯作者：
Andersen EC
中科院分区：
文献类型：
--
作者：
Lee D;Zdraljevic S;Stevens L;Wang Y;Tanny RE;Crombie TA;Cook DE;Webster AK;Chirakar R;Baugh LR;Sterken MG;Braendle C;Félix MA;Rockman MV;Andersen EC
在不同的分类群中，自交物种已经从异交物种独立进化了数千次。从异交到自交的过渡显著降低了有效群体大小、有效重组率和物种内的杂合性。这些变化通过加强随机遗传漂变和连锁选择的影响，导致遗传多样性减少，从而降低适应潜力。在线虫属小杆线虫中，自交至少进化了三次，所有三个物种，包括模式生物秀丽小杆线虫，相对于异交物种显示出显著减少的遗传多样性。自交和异交的小杆线虫经常在同一生态位中发现，但我们仍然不知道遗传多样性有限的自交物种如何适应这些环境。在这里，我们研究了609个野生C。elegans菌株在世界范围内分离，并显示遗传变异集中在间断的超发散区域，覆盖了20%的C。线虫参考基因组。这些区域富含环境反应基因，介导感官知觉，病原体反应和异生物质应激反应。种群基因组证据表明，这些地区的遗传多样性是通过长期平衡选择维持的。使用15个野生菌株的长读段基因组组装，我们表明超趋异单倍型包含独特的基因组，并显示出与数百万年前趋异的小杆线虫物种之间的水平相当的趋异水平。这些结果为物种如何避免与自交相关的进化“死胡同”提供了一个例子。
Across diverse taxa, selfing species have evolved independently from outcrossing species thousands of times. The transition from outcrossing to selfing significantly decreases the effective population size, effective recombination rate, and heterozygosity within a species. These changes lead to a reduction in genetic diversity, and therefore adaptive potential, by intensifying the effects of random genetic drift and linked selection. Within the nematode genus Caenorhabditis, selfing has evolved at least three times and all three species, including in the model organism Caenorhabditis elegans, show substantially reduced genetic diversity relative to outcrossing species. Selfing and outcrossing Caenorhabditis species are often found in the same niches, but we still do not know how selfing species with limited genetic diversity can adapt to these environments. Here, we examine the whole-genome sequences from 609 wild C. elegans strains isolated worldwide and show that genetic variation is concentrated in punctuated hyper-divergent regions that cover 20% of the C. elegans reference genome. These regions are enriched in environmental response genes that mediate sensory perception, pathogen response, and xenobiotic stress response. Population genomic evidence suggests that genetic diversity in these regions has been maintained by long-term balancing selection. Using long- read genome assemblies for 15 wild strains, we show that hyper-divergent haplotypes contain unique sets of genes and show levels of divergence comparable to levels found between Caenorhabditis species that diverged millions of years ago. These results provide an example for how species can avoid the evolutionary “dead end” associated with selfing.
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影响因子：
30.8
作者：
Andersen, Erik C.;Gerke, Justin P.;Shapiro, Joshua A.;Crissman, Jonathan R.;Ghosh, Rajarshi;Bloom, Joshua S.;Felix, Marie-Anne;Kruglyak, Leonid
通讯作者：
Kruglyak, Leonid
影响因子：
4.5
作者：
Brandvain Y;Slotte T;Hazzouri KM;Wright SI;Coop G
通讯作者：
Coop G
影响因子：
4.9
作者：
Bao W;Kojima KK;Kohany O
通讯作者：
Kohany O
影响因子：
64.8
作者：
Chang, Howard C.;Paek, Jennifer;Kim, Dennis H.
通讯作者：
Kim, Dennis H.
Caenorhabdision秀丽隐杆线虫中的删除多态性RIG-I同源物可以禁用病毒RNA DICING和抗病毒免疫。
影响因子：
7.7
作者：
Ashe A;Bélicard T;Le Pen J;Sarkies P;Frézal L;Lehrbach NJ;Félix MA;Miska EA
通讯作者：
Miska EA