Repeated losses of PRDM9-directed recombination despite the conservation of PRDM9 across vertebrates
Repeated losses of PRDM9-directed recombination despite the conservation of PRDM9 across vertebrates
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DOI：
10.7554/elife.24133
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发表时间：
2017-06-06
期刊：
影响因子：
7.7
通讯作者：
Przeworski, Molly
中科院分区：
文献类型：
--
作者：
Baker, Zachary;Schumer, Molly;Przeworski, Molly
对高度分化物种的研究揭示了两种机制，通过这两种机制，减数分裂重组通过PRDM9结合或通过靶向启动子样特征被定向到基因组，这导致热点的显著不同的进化动力学。在这里，我们从225个物种的基因组和转录组数据中鉴定了PRDM9直系同源物。我们在远亲脊椎动物中发现了完整的PRDM9直系同源物，但是，尽管这种广泛的保守性，推断至少有六个部分和三个完全丢失。引人注目的是，携带PRDM9的完整直系同源物的分类群恰恰是其预测的结合亲和力快速进化的那些，这表明所有结构域都是指导重组所必需的。事实上，正如我们所展示的，剑尾鱼携带只有部分但保守的直系同源物与PRDM9敲除共享重组特性。
Studies of highly diverged species have revealed two mechanisms by which meiotic recombination is directed to the genome through PRDM9 binding or by targeting promoter-like features that lead to dramatically different evolutionary dynamics of hotspots. Here, we identify PRDM9 orthologs from genome and transcriptome data in 225 species. We find the complete PRDM9 ortholog across distantly related vertebrates but, despite this broad conservation, infer a minimum of six partial and three complete losses. Strikingly, taxa carrying the complete ortholog of PRDM9 are precisely those with rapid evolution of its predicted binding affinity, suggesting that all domains are necessary for directing recombination. Indeed, as we show, swordtail fish carrying only a partial but conserved ortholog share recombination properties with PRDM9 knock-outs.