Tracking the past: Interspersed repeats in an extinct Afrotherian mammal, Mammuthus primigenius
Tracking the past: Interspersed repeats in an extinct Afrotherian mammal, Mammuthus primigenius
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DOI：
10.1101/gr.091363.109
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发表时间：
2009-08-01
期刊：
影响因子：
7
通讯作者：
Schuster, Stephan C.
中科院分区：
文献类型：
--
作者：
Zhao, Fangqing;Qi, Ji;Schuster, Stephan C.
长毛猛犸象（Mammuthus primigenius）大约在几千年前灭绝，然而最近的古基因组学研究已经成功地从这个灭绝物种的线粒体和核基因组中恢复了遗传信息。猛犸象属于非洲兽目，这是一组表现出极端形态多样性和大基因组大小的哺乳动物。在这项研究中，我们发现猛犸象基因组包含比迄今为止报道的任何其他哺乳动物基因组更大比例的分散重复序列，其中RTE逆转录转座子家族的增殖（覆盖基因组的12%）可能是基因组大小增加的主要原因。系统发育分析表明，猛犸RTE与BovB/RTE家族亲缘关系密切。重建的RTE系统发育的不一致性表明猛犸象RTE可能是通过古代的侧面基因转移事件获得的。最近在原鲸谱系中也发现了鼻窦的增殖，而猛犸象的非猿人范围的鼻窦则经历了相当平缓和逐步的扩张。比较猛犸象和其他哺乳动物的转座因子（TEs），有助于揭示不同哺乳动物谱系中te的进化史。
The woolly mammoth (Mammuthus primigenius) died out about several thousand years ago, yet recent paleogenomic studies have successfully recovered genetic information from both the mitochondrial and nuclear genomes of this extinct species. Mammoths belong to Afrotheria, a group of mammals exhibiting extreme morphological diversity and large genome sizes. In this study, we found that the mammoth genome contains a larger proportion of interspersed repeats than any other mammalian genome reported so far, in which the proliferation of the RTE family of retrotransposons (covering 12% of the genome) may be the main reason for an increased genome size. Phylogenetic analysis showed that RTEs in mammoth are closely related to the family BovB/RTE. The incongruence of the reconstructed RTE phylogeny indicates that RTEs in mammoth may be acquired through an ancient lateral gene transfer event. A recent proliferation of SINEs was also found in the probocidean lineage, whereas the Afrotherian-wide SINEs in mammoth have undergone a rather flat and stepwise expansion. Comparisons of the transposable elements (TEs) between mammoth and other mammals may shed light on the evolutionary history of TEs in various mammalian lineages.