Molecular genetic ecology of the diversity in sika deer populations.

1. 目的：通过对日本梅花鹿种群间和种群内遗传变异水平的DNA分析，研究日本梅花鹿种群遗传多样性现状，探讨栖息地破碎化对遗传分化的影响。利用遗传资料评价各居群间的遗传分化水平和各居群间的遗传多样性水平。方法：在日本北海道、岩手、金山山、兵库县、山口、岛根、对马岛和长崎等10个地区采集梅花鹿DNA样本。基因扫描DNA片段分析检测了8个微卫星位点的遗传变异。结果与讨论：多重比较检验表明，除长崎种群外，金山山种群观察到的平均杂合度（Ho）与其他种群无显著差异；长崎人群的Ho极显著（p<0.01）低于金山山、兵库、岛根、对马岛和山口人群。各群体的期望杂合度（Ho）与平均期望杂合度（He）差异不显著。因此，我们得出结论，与大群体相比，小群体的杂合性不一定降低。杂合度的降低不能简单地用岛屿效应或当前的种群规模来解释。我们在Kinkazan人群中发现了相当大的遗传变异。强迫模拟研究表明，在种群规模一定的情况下，Kinkazan种群的杂合度在20代内会迅速下降。然而，实际的遗传多样性比模拟中预期的要大。这表明群体内的基因流动可以抵消孤立群体中基因漂变的影响。首先分析表明，尽管南北mtDNA单倍型群体之间没有明显的分离，但地方群体之间的遗传分化是明显的。因此，本研究所测试的微卫星标记被证明是解剖梅花鹿种群结构的有力工具。少

1. Object : To study current genetic diversity of local populations of Japanese sika deer, and to investigate the effect of habitat fragmentation over genetic differentiation, we measured the level of genetic variations among and within populations by DNA analyses. Genetic data were used to assess the level of genetic differentiation among populations and the level of genetic diversity in each population.2. Methods : We collected DNA samples of sika deer at ten localities in Japan : three from Hokkaido, Iwate, Kinkazan, Hyogo, Yamaguchi, Shimane, Tsushima, and Nagasaki. Genetic variations at eight microsatellite loci were detected by GeneScan DNA fragment analysis.3. Results and Discussion : Multiple comparison test revealed that average observed heterozygosity (Ho) in Kinkazan population did not differ from the others except Nagasaki ; Ho in Nagasaki population was significantly (p<0.01) lower than those in Kinkazan, Hyogo, Shimane, Tsushima, and Yamaguchi populations. We also found n … More o significant difference between Ho and average expected heterozygosity (He) in each population. We, therefore, concluded that heterozygosity in small population is not necessarily reduced in comparison with larger populations. The reduction in heterozygosity can not be explained simply by the island effect nor current population size. We detected considerable genetic variations in Kinkazan population. Compulter simulation study demonstrated that heterozygosity in Kinkazan population will decrease rapidly within 20 generation if the population size is constant. However, actual genetic diversity is greater than what expected from the simulation. This suggests that a gene flow within a population would conter the effect of genetic drift in an isolated population. Fst analysis showed that the genetic differentiation among local populations is evident although there are no clear separation between northern and southern mtDNA haplotype groups. The microsatellite markers tested in our study were, therefore, proved to be powerful tools in dissecting population structure of sika deer. Less