Sustainable genetic civersity in populations of the sika deer

为了研究自然种群遗传多样性水平的控制机制，我们对日本梅花鹿进行了种群遗传分析。首先，我们进行了基于人口的分析。对奈良美县吉野熊野地方人口的种群结构进行了分析。线粒体和微卫星DNA分析表明，该种群保持了较高的遗传多样性水平。还发现Sizuoka种群保留了较高水平的遗传多样性。M比分析表明，两个种群都没有经历瓶颈，种群内的基因流动不受片断化的限制。相反，我们研究了两个地方种群的空间结构，Shoudosima和长崎种群降低了遗传多样性水平。大约三分之一的微卫星座位在长崎人群中是固定的。有人认为，Shoudosima种群由两个亚群组成，即北部和南部。…为了进一步检验亚群是否真的存在，我们利用微卫星数据进行了聚类分析。利用个体间的Cavalli-Sforza Edwards距离进行聚类。我们的结果清楚地表明，Shoudosima种群被细分为两个区域亚种群，它们之间的基因流动受到限制。第二，在金卡赞岛人群中开展了以个体为基础的研究。前期研究表明，金卡赞种群具有较高的遗传多样性，不能简单地用遗传漂移和突变平衡来解释。我们对-1997年出生在岛上的小牛进行了亲子鉴定，发现并不是所有的小牛都是研究地点的领地雄性繁殖的。显然，在研究种群中发生了群外交配。这就解释了为什么我们在金卡赞种群中观察到了高水平的遗传多样性。这种划分将有助于维持小种群中的遗传多样性。较少

To study the mechanism that controls the level of genetic diversity in natural population, we carried out population-genetic analyses of the sika deer in Japan. First, we conducted population-based analyses. Population structure was analyzed for Yoshino-Kumano local population in Nara-Mie prefectures. Both mitochondrial and microsatellite DNA analyses showed that this population keeps relatively high level of genetic diversity. Sizuoka population was also found to retain high level of genetic diversity. M ratio analysis revealed that both populations have not experienced bottlenecking and gene flow within a population is not restricted by fragmentation. In contrast, we study the spatial structuring of two local population, Shoudosima and Nagasaki populations that have reduced level of genetic diversity. About one-third of microsatellite loci was fixed in Nagasaki population. It has been suggested that Shoudosima population consists of two subpopulations, namely, northern and southern. … More To test whether the subpopulations really exist, we conducted cluster analysis by using microsatellite data. Clustering was made possible by taking Cavalli-Sforza Edwards distance between individual. Our results clearly indicate that Shoudosima population is subdivided in two regional subpopulation and gene flow between them was restricted. Second, we carried out individual-based study in Kinkazan island population. It has been shown by our previous study that Kinkazan population retain high level of genetic diversity, whish can not be explained simply by genetic drift and mutation equilibrium. We determined paternity of the calves born on the island between 1989-1997, and found that not all of the carves were sired by territorial males in the study site. It is obvious that extra-group mating took place in the study population. This would explain why we observed high level of genetic diversity in Kinkazan population. Such partitioning would contribute to the maintenance of genetic diversity in a small population. Less