Institute of Evolutionary Biology (UPF-CSIC), PRBB, c/ del Dr. Aiguader 88, 08003 Barcelona, Spain.
Center for Evolutionary Hologenomics, The Globe Institute, University of Copenhagen, Øster Farimagsgade 5A, 1352 Copenhagen, Denmark.
Genes (Basel). 2023 Mar 18;14(3):743. doi: 10.3390/genes14030743.
The critically endangered western gorillas () are divided into two subspecies: the western lowland () and the Cross River () gorilla. Given the difficulty in sampling wild great ape populations and the small estimated size of the Cross River gorilla population, only one whole genome of a Cross River gorilla has been sequenced to date, hindering the study of this subspecies at the population level. In this study, we expand the number of whole genomes available for wild western gorillas, generating 41 new genomes (25 belonging to Cross River gorillas) using single shed hairs collected from gorilla nests. By combining these genomes with publicly available wild gorilla genomes, we confirm that Cross River gorillas form three population clusters. We also found little variation in genome-wide heterozygosity among them. Our analyses reveal long runs of homozygosity (>10 Mb), indicating recent inbreeding in Cross River gorillas. This is similar to that seen in mountain gorillas but with a much more recent bottleneck. We also detect past gene flow between two Cross River sites, Afi Mountain Wildlife Sanctuary and the Mbe Mountains. Furthermore, we observe past allele sharing between Cross River gorillas and the northern western lowland gorilla sites, as well as with the eastern gorilla species. This is the first study using single shed hairs from a wild species for whole genome sequencing to date. Taken together, our results highlight the importance of implementing conservation measures to increase connectivity among Cross River gorilla sites.
极度濒危的西部低地大猩猩（）分为两个亚种：西部低地（）和克罗斯河（）大猩猩。鉴于在野生大型猿类种群中取样的难度以及对克罗斯河大猩猩种群规模的估计较小，迄今为止，仅对一只克罗斯河大猩猩进行了全基因组测序，这阻碍了对该亚种的群体水平研究。在这项研究中，我们使用从大猩猩巢中收集的单个脱落毛发，增加了可供野生西部大猩猩使用的全基因组数量，生成了 41 个新基因组（其中 25 个属于克罗斯河大猩猩）。通过将这些基因组与公开的野生大猩猩基因组相结合，我们证实克罗斯河大猩猩形成了三个种群聚类。我们还发现它们之间在全基因组杂合度方面几乎没有变化。我们的分析揭示了长的纯合性区域（>10 Mb），表明克罗斯河大猩猩最近存在近亲繁殖。这与山地大猩猩相似，但瓶颈期要近得多。我们还检测到两个克罗斯河地点（阿菲山野生动物保护区和姆贝山脉）之间过去的基因流动。此外，我们观察到克罗斯河大猩猩与北部西部低地大猩猩地点以及东部大猩猩物种之间过去的等位基因共享。这是迄今为止首次使用野生物种的单个脱落毛发进行全基因组测序的研究。总之，我们的研究结果强调了实施保护措施以增加克罗斯河大猩猩地点之间连通性的重要性。
