Comparative Phylogeography Of Chinese Rhinolophus Macrotis Complcx Based On NDNA

Big-eared horseshoe bat (Rhinolophus macrotis) is widely distributed in SouthAsia, Southeast Asia and the south of China. In2008, two cryptic species were found(large form and small form) in this species complex in Jiangxi Province, China. Thisprovides an important model to study the speciation and differentiation of siblingspecies. MtDNA analysis described a new cryptic lineage in this species complex inour prior study, but the existence of reproductive isolation between lineages or a newcrptic species in this new cryptic lineage is still unknown. Here we used two nDNAmarkers (microsatellite and RAG2) to study the population genetic differentiationwithin this species complex. We also compared our result to that of mtDNA to revealthe genetic differentiation and evolutionary history of large form and small form in R.macrotis complex, and provide important scientific basis for speciation and protectionof this species complex.A total of82individuals from16populations in10Chinese provinces werecollected. We analysed the genetic characteristics of big-eared horseshoe bats usingeight microsatellite and RAG2markers. Based on microsatellite data, we found thatboth of the two sibling species showed low alleleic richness but high observedheterozygosity. The RAG2gene also showed low genetic diversity for them.Furthermore, the results showed a significant genetic differentiation between the twoforms, and the small form in big-eared horseshoe bat had a higher population geneticdifferentiation compared to the large form. We inferred that geographical distances,terrain and special climate might be the key factors of the genetic differentiation.Phylogenetic analysis indicated historical introgression between the two forms andmale-mediated gene flow between the two large form lineages which were describedby mtDNA. Bayesian clustering analysis and assignment test indicated the existenceof hidden population genetic structure.Hence, compared the results of mtDNA and nDNA, the two forms of Chinesebig-eared horseshoe bat are two sibling species, but no cryptic species was found inlarge form by nDNA. Moreover, we estimated population expansion and divergence time estimates for the big-eared horshshoe bat complex with mitochondrial data. Wesuggested that several glacial refugia in the south of China problely existed for them.So the current distribution patterns of big-eard horseshoe bat might be contributed tothe expansion of populations from different refugia and second contact.