Abstract: Tibetan antelope (Pantholops hodgsonii), an endemic species of the Qinghai-Tibet Plateau, exhibits group living and sexual segregation behaviors. Outside the rutting season, male and female Tibetan antelope live separately. In this study, a total of 188 fresh fecal samples were collected from 32 groups of Tibetan antelope in the Kekexili region of the Sanjiangyuan National Park in late December 2021. Genetic diversity analysis and parentage testing were conducted using ten highly polymorphic microsatellite loci. The findings revealed that out of the 188 fresh fecal samples, genetic identification confirmed the presence of 145 individual Tibetan antelope. Among them, ten Tibetan antelope individuals (eight females and two males) sequentially appeared in different groups over time. Field observations indicated three mechanisms for recombination among mating groups including group dissolution, male departures or arrivals to/from existing groups, and female departures or arrivals to/from existing groups. Notably, there was considerable genetic differentiation between individuals that changed groups compared to those remaining within their original group composition. Male Tibetan antelopes moved to groups with a higher proportion of females than their previous ones, thereby increasing their potential for acquiring more mates and enhancing opportunities for gene inheritance. The average number of alleles across the ten microsatellite loci was 16. 1, with an average polymorphic information content of 0. 766. Observed heterozygosity (Ho) ranged from 0. 607 to 0. 993 with a mean value of 0. 819. Expected heterozygosity (He) ranged from 0. 575 to 0. 930 with a mean value of 0. 798. These results indicated a high level of genetic diversity within the Tibetan antelope population. At the group level, out of the total parent-child relationships observed (n = 32), fourteen (43. 75%) occurred within the same group, predominantly in mother-daughter relationships (71. 43 %), while only four (28. 57%) involved males (mother-son/father-daughter/father-son). By comparing the average coefficients of relatedness between groups with or without males, our findings suggested that the presence or absence of males had minimal impact on genetic relatedness among group members, indicating that closest genetic relationships within mating groups were primarily among females. Our findings demonstrated that low levels of inbreeding in Tibetan antelope populations and highlight female-female associations as key drivers for forming stable groups and facilitating communication and transmission of migration information due to their higher relatedness compared to males. These results provided scientific evidence supporting further validation of the collective memory conjecture regarding Tibetan antelope migration.

Key words: Tibetan antelope, Fecal DNA, Mating group, Parentage testing, Genetic diversity

摘要： 藏羚 (Pantholops hodgsonii) 是青藏高原特有物种，多集群生活且具有典型的性别分离现象。除交配季节外，雌雄两性个体组成的同性集群分开活动。本研究于 2021 年 12 月下旬在三江源国家公园可可西里片区以藏羚集群为单元采集了 32 个集群共 188 份新鲜粪便样品，利用多态性较高的 10 个微卫星位点进行亲缘关系鉴定与遗传多样性分析。结果表明：(1) 188 份新鲜粪便样品来自 145 只藏羚个体，其中 10 只藏羚个体 (8 只雌羚，2 只雄羚) 出现更换集群现象，导致前后集群发生变化。结合野外实地记录，推测藏羚交配群的变化存在 3 种方式：集群解散，雄性个体离开 (加入)，雌性个体离开 (加入)。新加入的藏羚个体与原集群成员间的亲缘关系较远。雄性藏羚更换的集群中雌性个体均多于之前的集群，能够获得更多交配机会。(2) 10 个微卫星位点的平均等位基因数为 16. 1，平均多态信息含量为 0. 766。观测杂合度(Ho) 0. 607 ~ 0. 993，平均值为 0. 819；期望杂合度 (He) 0. 575 ~0. 930，平均值为 0. 798，表明藏羚种群遗传多样性丰富。(3) 经过亲缘关系鉴定，种群内所有亲子关系中 14 对(43. 75%) 发生在集群内并且以母女 (71. 43%)为主，与雄性个体相关的亲子对 (母子/父女/父子) 有 4 对 (28. 57%)。对比集群内及集群间藏羚的平均亲缘系数，结果表明雄性个体对集群内成员间的亲缘关系影响不大。针对集群间藏羚亲缘关系的研究结果也表明，藏羚种群的近交比例处于较低水平。由于藏羚雌性比雄性个体有更多时间和机会组成含有多个雌性成员的集群，因此，集群内雌性个体的亲缘关系较高不仅有利于提高集群的稳定性，还有利于迁徙信息的交流和传递，从而为进一步验证藏羚迁徙的集体记忆猜想提供科学佐证。

关键词: 藏羚, 粪便DNA, 交配群, 亲缘关系, 遗传多样性