Izsvák Zsuzsanna, Wang Jichang, Singh Manvendra, Mager Dixie L, Hurst Laurence D
Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.
Department of Medical Genetics and British Columbia Cancer Agency, Terry Fox Laboratory, University of British Columbia, Vancouver, BC, Canada.
Bioessays. 2016 Jan;38(1):109-17. doi: 10.1002/bies.201500096.
Remnants of ancient retroviral infections during evolution litter all mammalian genomes. In modern humans, such endogenous retroviral (ERV) sequences comprise at least 8% of the genome. While ERVs and other types of transposable elements undoubtedly contribute to the genomic "junk yard", functions for some ERV sequences have been demonstrated, with growing evidence that ERVs can be important players in gene regulatory processes. Here we focus on one particular large family of human ERVs, termed HERVH, which several recent studies suggest has a key regulatory role in human pluripotent stem cells. Remarkably, this is not the first instance of an ERV controlling pluripotency. We speculate as to why this convergent evolution might have come about, suggesting that it may reflect selection on the virus to extend the time available for transposition. Alternatively it may reflect serendipity alone.
进化过程中古代逆转录病毒感染的残余物遍布所有哺乳动物基因组。在现代人类中，这类内源性逆转录病毒（ERV）序列至少占基因组的8%。虽然ERV和其他类型的转座元件无疑构成了基因组的“垃圾场”，但一些ERV序列的功能已得到证实，越来越多的证据表明ERV可能是基因调控过程中的重要参与者。在这里，我们聚焦于一个特定的人类ERV大家族，称为HERVH，最近的几项研究表明它在人类多能干细胞中具有关键调控作用。值得注意的是，这并非ERV控制多能性的首个实例。我们推测这种趋同进化为何会出现，认为这可能反映了病毒为延长转座可用时间而受到的选择。或者，这可能仅仅是出于偶然。
