| Golden snub-nosed monkey is a rare and endangered species endemic to China. Due to the disturbance of human beings, they are suffering from habitat loss and fragmenta-tion, and are confined to very limited areas in Qinling, Minshan and Shennongjia Moun-tains:This will cause loss in their genetic diversity, then they will be more sensitive to the natural disasters, environmental changes and population demographic effect. Un-derstanding the historical and current situation of R. roxellana can help designating the conservation strategy.I collect genetic samples of R. roxellana mainly from Qinling Mts., and use mi-crosatellite genotype data and mitochondrial D-Loop sequence to survey the genetic di-versity, population structure, dispersal model, demographic and evolution history of this species. The results are as follows:Genetic diversityTo conduct the survey,450noninvasive samples are amplified at20microsatellites loci, and428unique individuals and118alleles are segregated. The mean observed heterozygosity of R. r. qinlingensis is0.62, and the mean expected heterozygosity across troops is0.544. The genetic diversity is lower than the former studies, but is still relatively higher compare to the other endangered animals. Fifteen D-Loop haplotypes are detected in121noninvasive and specimen samples collected from24locations in Qinling Mts., the haplotype diversity h=0.838and nucleotide diversity π=1.053%. The mitochondrial diversity of R. r. qinlingensis is a bit lower than R. bieti.Population structureThe differentiation between troops is serious, AMOVA analyses indicating that the variation of microsatellites is mainly between individuals, while the variation of D-Loop is mainly between troops and reserves. Fortunately, the monkeys are able to dispersal be-tween bands within a same reserve, but isolation between reserves is strong. Bayesian clus-tering assigning3clusters, and the monkeys from Taibaishan, Guanyinshan and Huang-guan reserves are classified into a same cluster; the other two clusters consist of the bands from a same natural reserve. The migration of R. roxellana revealed by microsatellites accord with the isolation by barrier and landscape model, the main isolation factors are high-elevation, slope and land cover. The main ridge of Qinling Mts. is a barrier to the monkeys in short term, however, they can still cross it within thousands of years.Demographic historyI use five methods to detect the bottle-neck effect by microsatellite data, the results show there are three bands may suffer recent bottle-neck effect, but the majority of monkey troops has not significant signals of bottle-neck effect. The neutral tests are performed for both clades, except Fu’s Fs are significant negative, other tests are all insignificant and negative. Suggesting they may have experienced demographic expansion. Mismatch distributions and BSP analysis show both clades expanded in30to60kya BP. The restricted gene flow, allopatric fragmentation and contiguous range expansion are the main origin of the haplotypes of R. r. qinlingensis.Evolution historyBy sequencing the D-Loop gene for samples from Qinling Mts., Minshan Mts. and zoos, and combining the published sequences, five clades are defined. Their TMRCA was in920kya BP. Clade D in Minshan Mts. was divergent first, the TMRCA of other clades were in490kya BP. Clade C and E are originated from clade B, and entered Minshan and Shennongjia Mt. at260and320kya BP, respectively. Because no intermediate haplotype is found, more evidence is required. |
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