Chakraborty Debapriyo, Ramakrishnan Uma, Sinha Anindya
Nature Conservation Foundation, Mysore, India; National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India.
Am J Primatol. 2015 Mar;77(3):271-84. doi: 10.1002/ajp.22343. Epub 2014 Oct 5.
Multiple factors, including climate change, dispersal barriers, and social behavior influence the genetic structure of natural populations. While the effects of extrinsic factors such as historical climatic change and habitat topography have been well studied, mostly in temperate habitats, the simultaneous effects of intrinsic factors such as social behavior on genetic structure have rarely been explored. Such simultaneous effect, however, may particularly be common in social mammals such as many primates. Consequently, we studied the population structure of a rare and endangered social primate, the Arunachal macaque Macaca munzala, endemic to the northeastern Indian state of Arunachal Pradesh, located on the subtropical southern edge of the Tibetan Plateau and forming part of the Eastern Himalayan biodiversity hotspot. We studied a 534 bp-long mitochondrial DNA sequence and 22 autosomal microsatellite loci in individuals from three populations, Tawang, Upper Subansiri, and West Siang. The mtDNA data revealed three major divergence events: that between the Arunachal and bonnet macaques (ca. 1.61 mya), the founding of the West Siang population and the ancestral population of the present-day bonnet macaques (ca. 1.32 mya), and the divergence between the Tawang and Upper Subansiri populations (ca. 0.80 mya) that coincided with the major glacial events in the region. Comparing mitochondrial DNA with autosomal microsatellites, we also found evidence for female philopatry and male-driven long-distance gene flow. Arunachal macaques thus appear to be characterized by groups of philopatric females separated by geographical barriers and harsh climate but with dispersing males exerting a homogenizing effect on the nuclear gene pool. Given that severe population differentiation is of major concern in species conservation, we suggest that our study populations represent significant conservation units of this rare, endangered primate but, more importantly, emphasize the complex interplay of extrinsic and intrinsic factors in shaping the population structure of a social mammalian species.
多种因素，包括气候变化、扩散障碍和社会行为，都会影响自然种群的遗传结构。虽然诸如历史气候变化和栖息地地形等外在因素的影响已得到充分研究，且大多是在温带栖息地进行的研究，但社会行为等内在因素对遗传结构的同时影响却很少被探讨。然而，这种同时影响在许多灵长类等社会性哺乳动物中可能尤为常见。因此，我们研究了一种珍稀濒危的社会性灵长类——阿鲁纳恰尔猕猴（Macaca munzala）的种群结构，该猕猴是印度东北部阿鲁纳恰尔邦特有的物种，位于青藏高原亚热带南缘，是东喜马拉雅生物多样性热点地区的一部分。我们研究了来自三个种群（达旺、上苏班西里和西桑朗）个体的一段534 bp长的线粒体DNA序列和22个常染色体微卫星位点。线粒体DNA数据揭示了三个主要的分化事件：阿鲁纳恰尔猕猴和邦帽猕猴之间的分化（约161万年前）、西桑朗种群的形成以及当今邦帽猕猴祖先种群的形成（约132万年前），以及达旺和上苏班西里种群之间的分化（约80万年前），这与该地区的主要冰川事件相吻合。通过将线粒体DNA与常染色体微卫星进行比较，我们还发现了雌性留居和雄性驱动的长距离基因流动的证据。因此，阿鲁纳恰尔猕猴的特征似乎是由地理障碍和恶劣气候分隔开的留居雌性群体，但扩散的雄性对核基因库产生了均质化作用。鉴于严重的种群分化是物种保护中的主要问题，我们认为我们的研究种群代表了这种珍稀濒危灵长类的重要保护单元，但更重要的是，强调了外在和内在因素在塑造社会性哺乳动物物种种群结构中的复杂相互作用。
