Population Genetics Study On The Japanese Pipistrelle, Pipistrellus Abramus (Chiroptera: Vespertilionidae)

Compared to Europe and North America, the influence of climatic oscillations during the Pleistocene in shaping the distribution and genetic structure of biota in Asia is not well known. The influence of geographical barriers in promoting or restricting the dispersal ability of a species during post-glacial expansions will also have a large impact on its population genetic structure. The Japanese pipistrelle bat, Pipistrellus abramus, is found over a wide range in China, including Hainan Island and the Zhoushan Archipelago. Recently, in some areas, the number individuals of some bat species have dramatically been in decline due to seriously destructive ecological environment and fast development of towns. Genetic diversity is the basis of population long-term survival and resisting the diseases. Demographic history analysis is vital to population protection. In order to comprehensively understand survival status and demographic history and establish accurate protection steps for Pipistrellus abramus, it plays an important role in estimation of genetic diversity and gene flow between populations.We applied both mitochondrial (cytochrome b) and microsatellite markers to examine population genetic structure and demographic history in this species. The main results are as follows:1. We describe the first set of ten microsatellite markers isolated in Pipistrellus abramus. The number of alleles per locus ranged from 7 to 13. The observed and expected heterozygosities values ranged from 0.486 to 0.971 and from 0.752 to 0.876, respectively. Three loci (WW6,PA133 andl-20) revealed significant departure from Hardy-Weinberg equilibrium and no linkage disequilibrium was found between loci pairs. These informative microsatellite markers will be a powerful molecular tool for studying the population genetic structure of P. abramus, as well as other species of this genus.2. Both results of mtDNA and microsatellite DNA (8 loci) revealed Pipistrellus abramus contain relatively high genetic diversities among different geographic populations. For the mitochondrial DNA (mtDNA) data, the haplotype diversity ranged from 0.286 to 0.9, and nucleotide diversity ranged from 0.00025 to 0.01878. For the microsatellite data, the observed heterozygosity (HO) and expected (HE) heterozygosity ranged from 0.58 to 0.89 and from 0.67 to 0.82, respectively. The allelic richness (RS) ranged from 4.13 to 10.36 among sampled populations.3. Our results suggest that geographical features have had a clear impact on population connectivity in P. abramus. Specifically, both markers indicate that the Qiongzhou Strait, which separates Hainan Island from the China mainland, acts as a significant barrier to gene flow. Likewise, both genetic distance of mtDNA and microsatellite DNA were significant with natural geography distance (mtDNA, R2=0.27, P<0.001; microsatellite DNA, R2=0.31, P<0.001).4. Mismatch distributions show that populations from China mainland/Zhoushan Archipelago and Hainan Island appear to have undergone expansions since the Pleistocene, with evidence of a star-like topology in the former. Mt DNA reveals evidence of common ancestry between the colonies sampled on the Zhoushan Archipelago and those on the mainland, which are thought to have been isolated approximately 7000-9000 years ago. Although the Qiongzhou Strait seperates the Hainan Island and mainland for over 10000 years, no haplotype was found to share among individuals sampled from the island and mainland, and it revealed that the bats sampled from the Hainan Island may colony into the island via recent population expansion since the Pleistocene.5. Microsatellite data did not fully support the mitochondrial data and instead detected some differentiation between the two groups, highlighting the importance of using different markers at different spatial scales.In summary, we were explicit that the thesis data were combined with mitochondrial (cytochrome b) and microsatellite molecular markers for comparison of different geographical populations and geography distribution. Further more, the results were the basic study of phylogeography of the Japanese pipistrelle bat, Pipistrellus abramus.