Population Genetic Study on Breeding Structure and Local Differentiation of Japanese Macaques

为了检验日本猕猴种群结构模型和评价日本猕猴的局部分化，对线粒体DNA(MtDNA)分子变异和染色体结构变化进行了研究。用31种内切酶将35个地区的109份样本分成15种mtDNA单倍型。这些单倍型可以分为两类，在单倍型的地理分布上，(1)东北地区群体高度同质性，(2)东北地区群体表现出独特的单倍型，(3)地方群体对mtDNA变异的变异较小，当存在多态时，成年雄性个体也参与其中。这些结果不仅可能是群体结构、母系群体分裂、女性婚恋等社会生态或人口学特征的结果，也可能与过去群体分裂的历史，特别是日本东部冰川后的扩张有关。这些结果表明，以前建立的日本猕猴群体结构模型所假设的基因频率分布和群体内遗传变异性的平衡，至少对最近可能发生随机遗传漂移的一些地方群体是不支持的。对20个群体的75个样本的C-显带带型的细胞遗传学研究发现，除了已知的9号染色体着丝粒周围区域的数量变异外，还有新的染色体变异。它们是：9号染色体上核仁组织者区域的串联复制和染色体上姐妹染色单体的横向不对称C带。这些新的染色体变异是在志贺高地人群中发现的。为今后日本猕猴种群的研究奠定了基础。

Molecular variations in mitochondrial DNA (mtDNA) and structural changes in chromosomes were examined for testing the model of population structure and for evaluation of local differentiation of Japanese macaques. A total of 109 samples from 35 localities were types into 15 mtDNA haplotypes by 31 endonucleases. Those haplotypes could be grouped into two clusters, then, in geographic distribution of the haplotypes, (1) populations in northeastern part were highly homogeneous, (2) Goyosan population showed unique haplotypes among the northeastern populations, (3) local populations are generally less variable with respect to mtDNA variations, then, when polymorphism existed, adult males were involved. Those results may result not only from socioecological or demographic features, such as group structure, matrilineal group fission, female philopatry, but also from history of group division in the past, especially postglacial expansion in east Japan. The present results suggest that the equilibrium of gene frequency distribution and genetic variability within populations assumed in previous modeling of population structure of Japanese macaques could not be supported at least for some local populations where random genetic drift might take place in recent.Cytogenetical study of C-banding patterns for 75 samples from 20 populations revealed new chromosomal variations apart from a quantitative variation at pericentric region of chromosome 9 known previously. They are ; tandem duplication of nucleolar organizer region in chromosome 9 and lateral asymmetric C-band of sister chromatids in a chromosome. These new chromosomal variants were found in Shiga-Highland population. They are applicable in future for the population study of Japanese macaques.