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

研究了日本猕猴线粒体DNA （mtDNA）的分子变异和染色体的结构变化，以检验种群结构模型和评价日本猕猴的局部分化。来自35个地区的109份样品被31个内切酶分型为15个mtDNA单倍型。这些单倍型可分为两类，在地理分布上：(1)东北地区群体具有高度的同质性；(2)Goyosan群体在东北地区群体中表现出独特的单倍型；(3)当地群体mtDNA变异普遍较小，多态性存在时以成年雄性为主。这些结果可能不仅来自社会生态或人口特征，如群体结构、母系群体裂变、女性哲学，而且还来自过去的群体划分历史，特别是日本东部冰川后的扩张。目前的研究结果表明，日本猕猴种群结构模型中假设的种群内基因频率分布和遗传变异的平衡，至少在近期可能发生随机遗传漂变的局部种群中是不成立的。对来自20个群体的75个样本的c带模式进行细胞遗传学研究，发现除了已知的9号染色体周围中心区域的定量变异外，还有新的染色体变异。他们是；9号染色体核仁组织区串联重复和染色体姐妹染色单体的侧不对称c带。这些新的染色体变异是在志贺高原人群中发现的。它们可用于今后日本猕猴的种群研究。

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.