Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA.
State Key Laboratory of Genetic Engineering, Human Phenome Institute, Zhangjiang Fudan International Innovation Center, School of Life Science, Fudan University, Shanghai 200438, China.
Curr Biol. 2023 Nov 20;33(22):4905-4916.e5. doi: 10.1016/j.cub.2023.09.066. Epub 2023 Oct 13.
Comparisons of Neanderthal genomes to anatomically modern human (AMH) genomes show a history of Neanderthal-to-AMH introgression stemming from interbreeding after the migration of AMHs from Africa to Eurasia. All non-sub-Saharan African AMHs have genomic regions genetically similar to Neanderthals that descend from this introgression. Regions of the genome with Neanderthal similarities have also been identified in sub-Saharan African populations, but their origins have been unclear. To better understand how these regions are distributed across sub-Saharan Africa, the source of their origin, and what their distribution within the genome tells us about early AMH and Neanderthal evolution, we analyzed a dataset of high-coverage, whole-genome sequences from 180 individuals from 12 diverse sub-Saharan African populations. In sub-Saharan African populations with non-sub-Saharan African ancestry, as much as 1% of their genomes can be attributed to Neanderthal sequence introduced by recent migration, and subsequent admixture, of AMH populations originating from the Levant and North Africa. However, most Neanderthal homologous regions in sub-Saharan African populations originate from migration of AMH populations from Africa to Eurasia ∼250 kya, and subsequent admixture with Neanderthals, resulting in ∼6% AMH ancestry in Neanderthals. These results indicate that there have been multiple migration events of AMHs out of Africa and that Neanderthal and AMH gene flow has been bi-directional. Observing that genomic regions where AMHs show a depletion of Neanderthal introgression are also regions where Neanderthal genomes show a depletion of AMH introgression points to deleterious interactions between introgressed variants and background genomes in both groups-a hallmark of incipient speciation.
尼安德特人基因组与解剖学上现代人类（AMH）基因组的比较表明，尼安德特人与 AMH 之间存在杂交的历史，这是 AMH 从非洲迁徙到欧亚大陆后发生的。所有非撒哈拉以南非洲的 AMH 都有与尼安德特人相似的基因组区域，这些区域是由这种杂交产生的。在撒哈拉以南非洲人群中也发现了与尼安德特人相似的基因组区域，但它们的起源尚不清楚。为了更好地了解这些区域在撒哈拉以南非洲的分布情况、它们的起源以及它们在基因组中的分布情况对早期 AMH 和尼安德特人进化的启示，我们分析了来自 12 个不同撒哈拉以南非洲人群的 180 个人的高覆盖率全基因组序列数据集。在具有非撒哈拉以南非洲血统的撒哈拉以南非洲人群中，多达 1%的基因组可以归因于最近由来自黎凡特和北非的 AMH 群体迁徙和随后的混合所引入的尼安德特人序列。然而，撒哈拉以南非洲人群中的大多数尼安德特人同源区域起源于大约 250 万年前 AMH 人群从非洲迁徙到欧亚大陆，并与尼安德特人发生混合，导致尼安德特人中大约有 6%的 AMH 血统。这些结果表明，AMH 已经多次从非洲迁徙，并且尼安德特人和 AMH 之间的基因流动是双向的。观察到 AMH 显示尼安德特人基因渗入减少的基因组区域也是尼安德特人基因组显示 AMH 基因渗入减少的区域，这表明在两组背景基因组中，渗入变体之间存在有害相互作用——这是新物种形成的标志。
