Emergence of young human genes after a burst of retroposition in primates.
Emergence of young human genes after a burst of retroposition in primates.
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DOI：
10.1371/journal.pbio.0030357
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发表时间：
2005-11
期刊：
影响因子：
9.8
通讯作者：
Kaessmann, Henrik
中科院分区：
文献类型：
--
作者：
Marques, Ana Claudia;Dupanloup, Isabelle;Vinckenbosch, Nicolas;Reymond, Alexandre;Kaessmann, Henrik
通过基因复制产生的新基因是谱系或物种特异性表型性状进化的基础。在这份报告中，我们估计了灵长类动物中高比率的逆转录（逆转录复制）所产生的导致人类的谱系上的功能性逆转录基因的数量。广泛的比较测序和表达研究，再加上进化分析和模拟表明，最近的逆转录代表真正的人类基因的显着比例。我们估计，在过去的1.63亿年灵长类进化中，每百万年至少有一个新的逆转录基因出现在人类谱系中。一个子集的数据的详细分析表明，大多数的逆转录基因特异性表达在睾丸，而他们的父母的基因显示广泛的表达模式。因此，大多数逆转录基因在精子发生中发挥功能作用。由X染色体衍生的逆转录基因编码的蛋白质在重复事件后通过纯化选择而被强烈保留，支持了它们可能在晚期精子发生基因的X失活期间充当功能性常染色体替代物的观点。此外，一些逆转录基因获得了新的或更适应的功能，由正选择驱动。我们的结论是，逆转录复制显着促进了最近的人类基因的形成，大多数新的逆转录基因在灵长类动物进化过程中逐步招募自然和/或性选择，以提高男性生殖系功能。在人类中，逆转录-从mRNA逆转录的DNA整合到基因组中-有助于形成最近的功能基因，以增强男性生殖系功能。
The origin of new genes through gene duplication is fundamental to the evolution of lineage- or species-specific phenotypic traits. In this report, we estimate the number of functional retrogenes on the lineage leading to humans generated by the high rate of retroposition (retroduplication) in primates. Extensive comparative sequencing and expression studies coupled with evolutionary analyses and simulations suggest that a significant proportion of recent retrocopies represent bona fide human genes. We estimate that at least one new retrogene per million years emerged on the human lineage during the past ∼63 million years of primate evolution. Detailed analysis of a subset of the data shows that the majority of retrogenes are specifically expressed in testis, whereas their parental genes show broad expression patterns. Consistently, most retrogenes evolved functional roles in spermatogenesis. Proteins encoded by X chromosome−derived retrogenes were strongly preserved by purifying selection following the duplication event, supporting the view that they may act as functional autosomal substitutes during X-inactivation of late spermatogenesis genes. Also, some retrogenes acquired a new or more adapted function driven by positive selection. We conclude that retroduplication significantly contributed to the formation of recent human genes and that most new retrogenes were progressively recruited during primate evolution by natural and/or sexual selection to enhance male germline function. In humans, retroposition--integration into the genome of DNA reverse transcribed from mRNA--has contributed to the formation of recent functional genes selected to enhance male germline function.