Microsatellite Genetic Diversity and Population Structure of the Endangered Reeves’ Turtles (Mauremys reevesii) in South Korea

To understand the genetic diversity and population structure this study were examined using microsatellite (MS) genotypes in two Reeves’ turtle populations in South Korea. Mean observed and expected heterozygosities and polymorphic information content were 0.555, 0.595 and 0.564 in Geumgok population and 0.550, 0.633 and 0.591 in Gangjin-Yeongam population, respectively. Genetic diversity levels of Korean turtles showed higher than those of Chinese and Taiwanese captive breeding populations but lower than those of two Chinese populations collected from broad geographic range. Among nine MS loci tested, six loci in Geumgok population and two loci in Gangjin-Yeongam population showed significantly departed from Hardy-Weinberg equilibrium (PHW<0.05). Positive inbreeding coefficient (FIS) values were found, estimating that inbreeding occurred. On the other hand, negative FIS estimated to be introgression of exotic gene pools at the past. The genetic structure exhibited a fitting constant K=2, along with separation between both populations. The results from FCA, structure and phylogenetic analyses showed that these populations shared almost alleles except for several individuals but clustered into different branches on the phylogenetic tree, indicating that both populations had the similar ancestral origins but current populations formed by different reproduction processes. Our findings suggest that the two populations have experienced severe genetic bottlenecks in the past and have been growing their populations through a breeding process including inbreeding since the introgression of exotic gene pools. This study will provide important information for developing management programs for enhancing the genetic diversity and the population stability of the endangered Reeves’ turtle in South Korea.