Admixture and natural selection shaped genomes of an Austronesian-speaking population in the Solomon Islands
Admixture and natural selection shaped genomes of an Austronesian-speaking population in the Solomon Islands
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DOI：
10.1038/s41598-020-62866-3
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发表时间：
2020-04-23
影响因子：
4.6
通讯作者：
Ohashi, Jun
中科院分区：
文献类型：
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作者：
Isshiki, Mariko;Naka, Izumi;Ohashi, Jun
今天所罗门群岛上的人们被认为是亚洲和巴布亚人的祖先。巴布亚人的祖先大约在47000年前在大洋洲附近定居，而亚洲人的祖先是大约3500年前从东南亚迁移过来的南岛人（AN），称为拉皮塔人。在拉皮塔人扩展到遥远的大洋洲之前，这两个祖先种群在近大洋洲混在一起。为了了解这种混合对近大洋洲讲an的美拉尼西亚人适应的影响，我们对所罗门群岛西部新乔治亚群岛主要城镇Munda的21个个体进行了全基因组单核苷酸多态性（SNP）分析。蒙达的人口样本在基因上与所罗门群岛其他人口样本相似。两种不同祖先对Munda基因组的遗传贡献分析显示，在含有膜联蛋白A1 （ANXA1）基因的区域（亚洲成分> 82.6%）和人类白细胞抗原（HLA） II类区域（巴布亚成分> 85.4%）中，亚洲和巴布亚相关祖先的比例分别显著较高。这些地区被怀疑自混合时代起就经历了自然选择。我们的研究结果表明，这种混合影响了所罗门群岛上说安语的美拉尼西亚人的适应。
People in the Solomon Islands today are considered to have derived from Asian- and Papuan-related ancestors. Papuan-related ancestors colonized Near Oceania about 47,000 years ago, and Asian-related ancestors were Austronesian (AN)-speaking population, called Lapita, who migrated from Southeast Asia about 3,500 years ago. These two ancestral populations admixed in Near Oceania before the expansion of Lapita people into Remote Oceania. To understand the impact of the admixture on the adaptation of AN-speaking Melanesians in Near Oceania, we performed the genome-wide single nucleotide polymorphism (SNP) analysis of 21 individuals from Munda, the main town of the New Georgia Islands in the western Solomon Islands. Population samples from Munda were genetically similar to other Solomon Island population samples. The analysis of genetic contribution from the two different ancestries to the Munda genome revealed significantly higher proportions of Asian- and Papuan-related ancestries in the region containing the annexin A1 (ANXA1) gene (Asian component > 82.6%) and in the human leukocyte antigen (HLA) class II region (Papuan component > 85.4%), respectively. These regions were suspected to have undergone natural selection since the time of admixture. Our results suggest that admixture had affected adaptation of AN-speaking Melanesians in the Solomon Islands.