众所周知,恒河猴(Macaca mulatta)是最重要的灵长类实验动物之一,也是灵长类中最广布的类群,从西面的阿富汗到东面的中国沿海,从喜马拉雅山的南麓到印度中部,从中国的广大中南部到印支半岛中部的广阔区域都有分布。因而,恒河猴可能是研究高原形成与非人灵长类遗传结构相关影响的最佳模式生物。
昆明动物研究所张亚平院士课题组与四川大学岳碧松教授课题组合作,运用系统地理学的方法,对中国多个地点的野生恒河猴群体的遗传结构和进化史进行了系统研究。我们同时选取母系遗传的线粒体基因和核基因遗传的微卫星基因两种不同的分子标记,运用一系列的系统地理学的分析工具,对两组数据进行了全面的分析。研究结果表明两种分子标记所反映的遗传结构显著不同:线粒体数数据表明恒河猴大约形成在2.31个百万年前,在中国境内大约在1.15个百万年前形成了东部和西部两大单倍型组。相对于东部单倍型组呈现出的更大的单倍型多样度,西部单倍型组呈现出了更多的地理遗传结构,这一遗传结构的形成可能与发生在更新世晚期的青藏高原的隆升和第四纪冰川两大地质事件有关。微卫星数据的分析结果支持东部和西部两大单倍型组之间没有明显的分化,从西部到东部方向具有更大的基因流动。由雄性个体在不同群体之间的迁移所形成的基因流动,可能导致了母系遗传的线粒体相对于两性遗传的微卫星具有更大的分化。此外,我们也从保护生物学的角度提出了相应的意见:在东部和西部两大群体分开保护的同时,特别注重遗传多样性较低的海南、河南等群体的保护。基于前人对猕猴群体的研究主要是针对实验圈养的个体,本次研究主要是对野生群体进行了研究,这对实验圈养的个体下一步确定单倍型类型提供了重要参考。由四川大学的武善金博士和云南大学的罗静副研究员作为共同第一作者。本次发表的受到编辑和审稿人的一致好评,认为是猕猴野生群体遗传学方面重要的研究。(生物谷Bioon.com)
doi:10.1371/journal.pone.0055315
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Ecological Genetics of Chinese Rhesus Macaque in Response to Mountain Building: All Things Are Not Equal
Shan-Jin Wu equal contributor,Jing Luo equal contributor,Qing-Qing Li,Yan-Qin Wang,Robert W. Murphy,Christopher Blair,Shi-Fang Wu,Bi-Song Yue ,Ya-Ping Zhang
Background
Pliocene uplifting of the Qinghai-Tibetan Plateau (QTP) and Quaternary glaciation may have impacted the Asian biota more than any other events. Little is documented with respect to how the geological and climatological events influenced speciation as well as spatial and genetic structuring, especially in vertebrate endotherms. Macaca mulatta is the most widely distributed non-human primate. It may be the most suitable model to test hypotheses regarding the genetic consequences of orogenesis on an endotherm.
Methodology and Principal Findings
Using a large dataset of maternally inherited mitochondrial DNA gene sequences and nuclear microsatellite DNA data, we discovered two maternal super-haplogroups exist, one in western China and the other in eastern China. M. mulatta formed around 2.31 Ma (1.51–3.15, 95%), and divergence of the two major matrilines was estimated at 1.15 Ma (0.78–1.55, 95%). The western super-haplogroup exhibits significant geographic structure. In contrast, the eastern super-haplogroup has far greater haplotypic variability with little structure based on analyses of six variable microsatellite loci using Structure and Geneland. Analysis using Migrate detected greater gene flow from WEST to EAST than vice versa. We did not detect signals of bottlenecking in most populations.
Conclusions
Analyses of the nuclear and mitochondrial datasets obtained large differences in genetic patterns for M. mulatta. The difference likely reflects inheritance mechanisms of the maternally inherited mtDNA genome versus nuclear biparentally inherited STRs and male-mediated gene flow. Dramatic environmental changes may be responsible for shaping the matrilineal history of macaques. The timing of events, the formation of M. mulatta, and the divergence of the super-haplogroups, corresponds to both the uplifting of the QTP and Quaternary climatic oscillations. Orogenesis likely drove divergence of western populations in China, and Pleistocene glaciations are likely responsible for genetic structuring in the eastern super-haplogroup via geographic isolation and secondary contact.