Baskaev K K, Buzdin A A
Zh Obshch Biol. 2012 Jan-Feb;73(1):3-20.
Mobile elements are DNA fragments that are able to self-replicate within the genome of a host organism. Usually, mobile elements comprise about 40-50% of mammalian genome. In the present review, evolutionary recent insertions of mobile elements are considered which have occurred after divergence of human and chimpanzee ancestral forms, i.e. later than about 6 million years. Human-specific transposable elements are represented by relatively small number of copies that can be subdivided into four groups: HERV-K (HML-2), L1, Alu, and SVA. The number of human-specific copies of HERV-K (HML-2), L1, Alu, and SVA representatives amounts roughly to 150, 1200, 5500, and 860 copies per genome respectively. Furthermore, we succeeded in describing a new family of human-specific mobile elements that are present only in human genome and are absent in other primates. Insertions of human-specific mobile elements can be regarded as important candidates for the role of molecular-genetic agents of anthropogenesis--each new insertion of such a mobile element supplies the acceptor gene locus with the set of new functional sites for binding transcription factors that can make significant alterations to adjacent genes functioning. On the basis of known evidences confirming the influence of human-specific mobile elements on adjacent genes expression, total number of human genes regulated by them can be estimated like hundreds.
移动元件是能够在宿主生物基因组内自我复制的DNA片段。通常,移动元件约占哺乳动物基因组的40 - 50%。在本综述中,我们考虑了人类和黑猩猩祖先形式分化之后,即大约600万年后发生的移动元件的近期进化插入。人类特有的转座元件由相对较少数量的拷贝代表,可分为四组:HERV-K(HML-2)、L1、Alu和SVA。HERV-K(HML-2)、L1、Alu和SVA代表的人类特有的拷贝数分别约为每个基因组150、1200、5500和860个拷贝。此外,我们成功描述了一个仅存在于人类基因组中而在其他灵长类动物中不存在的人类特有的移动元件新家族。人类特有的移动元件的插入可被视为人类起源分子遗传因素作用的重要候选者——此类移动元件的每一次新插入都会为受体基因座提供一组新的功能位点,用于结合转录因子,这可能会对相邻基因的功能产生重大改变。基于证实人类特有的移动元件对相邻基因表达有影响的已知证据,可以估计受它们调控的人类基因总数有数百个。