基于微卫星的欧亚水獭个体识别和遗传多样性  

Individual identification and genetic diversity of Eurasian otters based on microsatellite markers

作　　者：郑凯丹 汪巧云 范朋飞[1,2] 韩雪松 肖梅 谌利民 董正一[3] 张璐 ZHENG Kaidan;WANG Qiaoyun;FAN Pengfei;HAN Xuesong;XIAO Mei;SHEN Limin;DONG Zhengyi;ZHANG Lu(School of Life Sciences,Sun Yat-sen University,Guangzhou 510275,China;State Key Laboratory of Biological Control,Sun Yat-sen University,Guangzhou 510275,China;Shan Shui Conservation Center,Beijing 100871,China;Center for Nature and Society,College of Life Sciences,Peking University,Beijing 100871,China;Tangjiahe National Nature Reserve Adiministration Bureau,Guangyuan 628109,China;School of Ecology,Sun Yat-sen University,Shenzhen 518107,China)

机构地区：[1]中山大学生命科学学院,广州510275 [2]中山大学水产动物疫病防控与健康养殖全国重点实验室,广州510275 [3]山水自然保护中心,北京100871 [4]北京大学生命科学学院自然保护与社会发展研究中心,北京100871 [5]四川省唐家河国家级自然保护区管理处,广元628109 [6]中山大学生态学院,深圳518107

出　　处：《兽类学报》2024年第2期146-158,共13页Acta Theriologica Sinica

基　　金：国家自然科学基金青年基金项目(31900372)。

摘　　要：种群数量和遗传多样性是保护濒危物种所需的基础信息。欧亚水獭(Lutra lutra)属于国家二级保护动物,曾经在我国分布广泛,但在20世纪经历了大规模的种群数量下降和分布区缩减。欧亚水獭相关研究十分缺乏,种群数量调查和遗传多样性等基础研究亟待开展。本研究采用非损伤性取样法,于2019—2020年在青海省玉树藏族自治州玉树市和四川省广元市青川县的主要河流共采集270个欧亚水獭粪便样品并进行DNA提取,基于9个微卫星位点和SRY基因分子标记进行个体识别和性别鉴定,进而使用非损伤性标志重捕法Capwire估计两地水獭的种群数量,并基于微卫星分型数据评估两个种群的遗传多样性。最终共有67个粪便样品(24.8%)成功分型7~9个微卫星位点并用于个体识别,共识别出玉树市10个个体、青川县30个个体,雌雄性比分别为4:5、15:14,两地各有1个个体未成功鉴定性别。估计研究区域内玉树的水獭种群数量为13只(95%置信区间:7~21只)、青川县的水獭种群数量为75只(95%置信区间:59~133只)。玉树、青川种群的平均观测杂合度H_(O)分别为0.680、0.664,平均期望杂合度HE分别为0.611、0.658,表明两个水獭种群均具有中等的微卫星遗传多样性。玉树、青川种群的平均F_(ST)为0.238,平均近亲繁殖系数F_(IS)分别为-0.121、-0.010,表明两个水獭种群之间分化显著,且种群内近交程度低。本研究是我国大陆地区基于粪便DNA对欧亚水獭进行种群数量估计和遗传多样性评估,可为我国水獭的保护提供重要的基础信息。Population size and genetic diversity are important basic information for threatened species conservation.As a Class II protected animal,Eurasian otter(Lutra lutra)was once widely distributed in China,but has experienced severe population decline and range shrinkage over the 20th century.However,only a few studies have been conducted on Eurasian otters in China.Basic research such as population surveys and genetic diversity studies are urgently needed.We collected 270 otter spraints for DNA extraction during 2019‒2020 in Yushu City,Qinghai Province and Qingchuan County,Guangyuan City,Sichuan Province.We used 9 microsatellite loci and the SRY gene to genotype individuals and iden‐tify sex.Then we estimated the sizes of the two populations based on individual identification and noninvasive capture-recapture method(Capwire).We also assessed their genetic diversity based on the nine microsatellite markers.We suc‐cessfully genotyped 67 spraints(24.8%)with 7-9 microsatellites and identified 40 otter individuals.Among them,10 were from Yushu and 30 were from Qingchuan,with a sex ratio of 4F/5M and 15F/14M respectively.Sex identification failed for two individuals.The estimated population of otters within our study area was 13(95%CI:7-21)in Yushu City and 75(95%CI:59-133)in Qingchuan County.The average observed heterozygosity(H_(O))and expected heterozy‐gosity(H_(E))of the Yushu population were 0.680 and 0.611,while those of the Qingchuan population were 0.664 and 0.658,revealing a moderate genetic diversity.Otters in Yushu and Qingchuan have been differentiated significantly(F_(ST)=0.238)and no significant inbreeding was found in both populations(F_(IS):Yushu−0.121,Qingchuan−0.010).As the first study estimating population size and genetic diversity of Eurasian otters based on fecal DNA in Chinese main‐land,our work provides important basic information for otter conservation in China.

关 键 词：欧亚水獭 粪便DNA 微卫星 种群数量 遗传多样性 

分 类 号：Q346[生物学—遗传学]