Isolation And Characterization Of Microsatellite DNA Markers From White-headed Langur And Genetic Diversity Study

The white-headed langur (Trachypithecus leucocephalus), is one of the numerous critically endangered species. It is distributed only in Karst hills in four counties in the southern Guangxi province of China. Because populations are highly fragmented and isolated, the total extant population was estimated to be less than 700 individuals. Therefore it was listed as one of the top 25 most endangered primate species in the world during 2002-2006. Proper knowledge of the genetic diversity of Trachypithecus leucocephalus will contribute to appropriate conservation management. However, little remains known about its genetic status and currently no molecular markers are available about this species.Microsatellite DNA is co-dominate genetic marker, which can reflect genetic information of individuals and parentage relationship. Thus it has been widely used in the study of population genetics in the last decade. In order to better understand of its genetic diversity and kinships, Population strueture and evolutionary history, as a powerful tool, we report the first isolation and characterization of 10 microsatellite loci in the white-headed langur.. The preliminary results are as follows:1. Microsatellites were isolated as the enrichment by magnetic beads. with slight modifications as follows. Whole genome DNA was extracted from a blood sample of white-headed langur using Animal Genomic DNA Extraction Kit (PUEX). Ten polymorphic loci were tested in 64 individuals from the Guangxi population at South China.2. The PIC values ranged from 0.590 to 0.874 with average value of 0.724 among these loci. 24 primer pairs succeeded in PCR amplification but only 10 primer dyads were polymorphic and consistently yielded their specific PCR products for each sample. These loci with both unknown parents and with only unknown sirewere 0.9935 and 0.9997, respectively, and both of them showed a total exclusionary power.3. A total of 78 distinct alleles were observed. The 10 loci were highly polymorphic with numbers of alleles per locus ranging from 4 to 14 with an average of 7.8. The mean expected heterozygosity (HE) and observed heterozygosity (HO) of these microsatellites were 0.778 and 0.562, respectively.4. All loci except for WHL-04 and WHL-05 locus followed Hardy–Weinberg expectations. No significant linkage association was found among all these loci. The 10 novel polymorphic microsatellite loci will be useful for conservation genetic study in this species.5. All the 10 microsatellite loci showed a total power in the study of the exclusionary analysis and the population genetic structure, which indicated that the microsatellite will play an important role in the study of the population genetics and conservation genetics in Trachypithecus leucocephalus. It also proved that the enrichment by magnetic beads is an availability and efficient method for microsatellite isolation in Trachypithecus leucocephalus.