基于亲权鉴定的千岛湖社鼠家群遗传结构与亲缘关系特征研究

Genetic structure and relatedness based on parentage analysis in family groups of Chinese white-bellied rats( Niviventer confucianus) in Thousand Island Lake

于2009年7月至2010年11月,对浙江千岛湖两个岛屿上的社鼠(Niviventer confucianus)种群进行标志重捕,并采用8个高多态性的微卫星位点,对两个岛屿的社鼠种群进行家群分析和亲权鉴定,探讨了社鼠家群的亲缘关系特征。结果显示,8个微卫星位点能可靠地对两个岛屿社鼠种群进行亲权鉴定,A岛已确定亲缘关系的71只社鼠分为12个家群,家群中的个体数最多达到19个,B岛已确定的49只社鼠个体共分为11个家群,家群中的个体数最多达到14个。家群内部成员之间的亲缘关系表现为配对繁殖的个体对间亲缘系数最小,揭示了社鼠倾向于选择亲缘关系较远的异性作为配偶。家群中雄性后代个体之间与雌性个体之间的亲缘关系相比,两岛表现情况相反,该结果暗示两岛屿上社鼠扩散行为可能有所不同。通过计算与同一雄性(或同一雌性)交配的个体间的亲缘系数,发现两个岛屿上的社鼠在与不同异性交配时也存在选择性,即避免选择亲缘关系较近的异性作为混交的对象。

We analyzed the parentage of Chinese white-bellied rats （Niviventer confucianus） that were mark-recaptured from July 2009 to November 2010 on two islands in Thousand Island Lake, Zhejiang Province, by using eight highly polymorphic microsatellite loci, and explored the characteristics of the relatedness between family groups. These eight loci can indicate the parentage of Chinese white-bellied rat populations on the two islands reliably. According to the results, 71 individuals from island A were divided into 12 family groups, the largest of which contained 19 members. The 49 individuals from island B were divided into 11 family groups, the largest of which contained 14 members. The relatedness of male-female pairs for reproduction （M-F pair） was lowest compared with other pairwise comparison, suggesting that the Chinese white-bellied rats could avoid inbreeding. Relatedness of male-male （M-M） and female-female （F-F） among offspring showed inconsistent performances between island A and island B, suggesting different dispersal particularities. Relatedness of the individual pairwise mating with the same male or female provided some information regarding mate choices. We considered that Chinese white-bellied rats preferred to choose the mates with low relatedness.