研究揭示尼安德特人基因滲入的本質
作者:
小柯機器人發布時間:2020/4/25 13:05:36
近日,冰島大學Kari Stefansson、丹麥奧爾胡斯大學Mikkel Heide Schierup和Laurits Skov小組合作,通過研究27,566個冰島人基因組揭示了尼安德特人基因滲入的本質。這一研究成果在線發表在2020年4月22日的《自然》上。
研究人員通過對來自27,566個冰島人的全階段全基因組序列中檢測到的1,440萬個假定古染色體片段的研究,檢測了尼安德特人基因滲入的影響;這些數據對應範圍為56,388–112,709獨特古染色體片段,覆蓋了可調用基因組的38.0–48.2%。
基於與已知古基因組的相似性,研究人員將84.5%的片段與阿爾泰山脈或迪亞尼安德特人來源的基因相匹配,將3.3%的片段與丹尼索瓦人相匹配,未知來源的片段佔12.2%。
研究發現,冰島人有比預期更多的丹尼索瓦人樣基因碎片。丹尼索瓦人基因流可以最好地解釋這一點,它可以滲入尼安德特人的祖先,也可以直接流入人類。個體片段與同形非片段個體的內部配對比較顯示,儘管在人類和尼安德特人世系分離的50萬年中,雖然總體突變率相似,但相對頻率不同突變類型可能是由於男性和女性世代間隔不同造成的。
最後,研究人員評估了271個表型,報告了5個由古老片段變體驅動的關聯,並揭示大多數先前報導的關聯可以由非古老變體解釋。
研究人員表示,人類進化史隨著不同群體的交融而豐富。除非洲之外的大多數人中約有2%的基因組是與尼安德特人基因的混合物,而尼安德特人的歷史發生在5萬至6萬年前。
附:英文原文
Title: The nature of Neanderthal introgression revealed by 27,566 Icelandic genomes
Author: Laurits Skov, Moiss Coll Maci, Garar Sveinbjrnsson, Fabrizio Mafessoni, Elise A. Lucotte, Margret S. Einarsdttir, Hakon Jonsson, Bjarni Halldorsson, Daniel F. Gudbjartsson, Agnar Helgason, Mikkel Heide Schierup, Kari Stefansson
Issue&Volume: 2020-04-22
Abstract: Human evolutionary history is rich with the interbreeding of divergent populations. Most humans outside of Africa trace about 2% of their genomes to admixture from Neanderthals, which occurred 50–60 thousand years ago1. Here we examine the effect of this event using 14.4 million putative archaic chromosome fragments that were detected in fully phased whole-genome sequences from 27,566 Icelanders, corresponding to a range of 56,388–112,709 unique archaic fragments that cover 38.0–48.2% of the callable genome. On the basis of the similarity with known archaic genomes, we assign 84.5% of fragments to an Altai or Vindija Neanderthal origin and 3.3% to Denisovan origin; 12.2% of fragments are of unknown origin. We find that Icelanders have more Denisovan-like fragments than expected through incomplete lineage sorting. This is best explained by Denisovan gene flow, either into ancestors of the introgressing Neanderthals or directly into humans. A within-individual, paired comparison of archaic fragments with syntenic non-archaic fragments revealed that, although the overall rate of mutation was similar in humans and Neanderthals during the 500 thousand years that their lineages were separate, there were differences in the relative frequencies of mutation types—perhaps due to different generation intervals for males and females. Finally, we assessed 271 phenotypes, report 5 associations driven by variants in archaic fragments and show that the majority of previously reported associations are better explained by non-archaic variants.
DOI: 10.1038/s41586-020-2225-9
Source: https://www.nature.com/articles/s41586-020-2225-9