基于微卫星DNA的神农架川金丝猴遗传结构研究

Genetic structure of the golden snub-nosed monkey in Shennongjia National Natural Reserve based on microsatellite DNA markers

川金丝猴(Rhinopithecus roxellana)是我国特有珍稀濒危物种,了解其种群遗传结构和关键影响因素,对该物种的保护具有重要意义。以我国分布最东端的湖北神农架川金丝猴种群为研究对象,基于非损伤性DNA技术和微卫星DNA遗传标记等分子生物学方法及景观遗传参数,探讨了神农架川金丝猴的遗传多样性和遗传结构,旨在为川金丝猴的研究及川金丝猴种群的可持续发展提供理论基础。利用12个多态性微卫星位点,在455份川金丝猴粪便样品中,共检测到62个微卫星等位基因;共鉴定出316个不同川金丝猴个体;种群的平均期望杂合度、平均观察杂合度和多态性信息含量分别为0.626、0.559和0.650;群体间的Nei's遗传距离为0.046—0.139,分化系数为0.015—0.046。结果表明与其他地区川金丝猴种群相比,神农架川金丝猴种群具有较低的遗传多样性水平,种群内部存在遗传分化趋势;结合景观参数分析表明地理距离不是影响神农架川金丝猴群体间遗传距离的主要因素,而生境中的灌丛和草地以及人类活动干扰可能是影响川金丝猴遗传交流的主要因素。

The golden snub-nosed monkey （Rhinopithecus roxellana） is an endemic and extremely endangered species in China. Understanding the population genetic structure of the golden snub-nosed monkey and the key factors affecting, it is very important for the protection of this species. The golden snub-nosed monkey population in the Shennongjia National Nature Reserve is an isolated population in the easternmost part of China. It is reported that out of three populations （Qinglin, Sichuan-Gansu, and Shennongjia）, the Shennongjia population is the smallest, and has the lowest genetic diversity. However, studies have shown that this population plays an important role in the genetic evolution of the species. Therefore, protection of the golden snub-nosed monkey in the Shennongjia National Nature Reserve is very important. In this study, genetic structure and genetic diversity of the golden snub-nosed monkey population in the Shennongjia National Nature Reserve were studied using molecular biology techniques and landscape genetics methods. These findings would provide a foundation for the sustainable development of populations and further research on the golden snub-nosed monkey. Twelve selected polymorphic microsatellite loci were used. A total of 455 fecal samples were collected from 11 sites where the monkeys often appear in four main distribution areas in the Shennongjia National Nature Reserve. There were 62 alleles detected, and the number of alleles identified per locus ranged from four to seven. The collected fecal samples belonged to 316 individual golden snub-nosed monkey. The distribution of high-frequency alleles in each locus followed similar trends among different golden snub-nosed monkey groups and study sites; however, the distribution of low-frequency alleles was different. The frequency of alleles less than 0.1 accounted for 21.53%--43.56% in different groups and different sites. The mean observed heterozygosity （Ho ）, mean expected heterozygosity （HE ） , and mean polymorphism information content （PIC） of the population in Shennongjia were 0.626, 0.559, and 0.650; the range of Ho, HE, and PIC among four groups in the Shennongjia National Nature Reserve were 0. 578--0. 639, 0. 515--0. 610, and 0. 600--0. 641, respectively. Differences in genetic diversity values among groups and sites were not significant. Compared with the Qinglin and Sichuan- Gansu populations, genetic diversity of the Shennongjia golden snub-nosed monkey was low. Nei＇s genetic distance of four populations ranged from 0.046 to 0.139, and their FST value ranged from 0.015 to 0.046. Genetic difference between the Dalongtan and Jinhouling groups was the greatest, and that between the Jinhouling and Qianjiaping groups was the lowest. The isolation-by-distance model showed that the genetic distance at different study sites was not significantly associated with geographic distance. Information from GIS （Geographic Information System） indicates that the main factors influencing the genetic distribution of the golden snub-nosed monkey in the Shenongjia National Nature Reserve were the interference from human activities and their fragmented habitats such as shrubs, grassland and road in the habitat, not their geographical distances.