Unit of Human Biology and Genetics, Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
Am J Phys Anthropol. 2018 Sep;167(1):61-71. doi: 10.1002/ajpa.23603. Epub 2018 May 8.
It has long been recognized that in gibbons both sexes disperse from the natal group. However, the fate of dispersed individuals was rarely documented. Here we provide the first detailed information on sex differences in dispersal patterns by analyzing the spatial genetic structure of a well-known white-handed gibbon (Hylobates lar) population.
Mitochondrial DNA (mtDNA) and Y-chromosomal haplotypes, and autosomal microsatellite genotypes were determined for individuals of the Mo Singto study site, Khao Yai National Park, Thailand. Mantel tests for the three genetic marker types were performed for 17 gibbon groups comprising 23 adult males and 18 adult females.
Significant positive Mantel correlations were observed for spatial distance and both autosomal microsatellite-based as well as Y-chromosomal haplotype-based genetic distance among adult males. Neighboring adult males tended to be genetically related and share Y-chromosomal haplotypes. Conversely, no significant Mantel correlations were observed either in autosomal microsatellites or mtDNA among adult females.
Our results confirm, at a genetic level, hypotheses from long-term demographic observations that white-handed gibbon males of the Mo Singto population primarily disperse into adjacent groups. Instead, females disperse more opportunistically either to adjacent or more distant groups. This sex-specific difference reflects an apparent greater tolerance between males than between females. The higher tolerance of adult males allows the formation of stable multimale groups and facilitates male dispersal into an adjacent group. Stable multifemale groups have never been documented for white-handed gibbons probably due to feeding competition between females.
长期以来，人们一直认为在长臂猿中，雌雄两性都从出生地群体中分散开。然而，分散个体的命运很少被记录下来。在这里，我们通过分析一个著名的白掌长臂猿（Hylobates lar）种群的空间遗传结构，提供了关于雌雄两性在分散模式上存在差异的第一个详细信息。
对泰国考艾国家公园 Mo Singto 研究点的个体进行了线粒体 DNA（mtDNA）和 Y 染色体单倍型以及常染色体微卫星基因型的测定。对包含 23 只成年雄性和 18 只成年雌性的 17 个长臂猿群体的三种遗传标记类型进行了 Mantel 检验。
在成年雄性中，空间距离与基于常染色体微卫星和 Y 染色体单倍型的遗传距离之间存在显著的正 Mantel 相关性。相邻的成年雄性往往具有遗传关系，并共享 Y 染色体单倍型。相反，在成年雌性中，无论是在常染色体微卫星还是 mtDNA 中，都没有观察到显著的 Mantel 相关性。
我们的结果从遗传水平上证实了 Mo Singto 种群白掌长臂猿雄性主要分散到相邻群体的长期人口统计观察假说。相反，雌性更随机地分散到相邻或更远的群体中。这种雌雄两性之间的差异反映了雄性之间明显比雌性之间更大的容忍度。成年雄性的较高容忍度允许形成稳定的多雄性群体，并促进雄性向相邻群体的扩散。稳定的多雌性群体从未在白掌长臂猿中记录过，可能是由于雌性之间存在食物竞争。
