Data from: Evaluating the reintroduction project of Przewalski’s horse in China using genetic and pedigree data

Przewalski's horse went extinct in the wild in the mid 1960’s. Starting in 1985, individuals were brought from western zoos to two centers in China and breeding programs were initiated. With the increasing size of captive populations, two reintroduction projects were launched in the northwestern China in 2001 and 2010. Knowledge on genetic diversity in China’s horse populations is limited, but would help improve the genetic management and assess the success of the reintroduction. Accordingly, one reintroduced and two captive populations were examined with 10 microsatellite loci together with pedigree data. The results showed higher level of diversity within the captive populations than the reintroduced population, indicating some alleles may have been lost during reintroduction. Genetic differentiation was detected among populations (FST=0.09±0.05, RhoST=0.05±0.02) and Bayesian clustering supported the presence of three subpopulations. The highest genetic differentiation was observed between the captive and reintroduced populations, and inbreeding coefficients were generally higher in the reintroduced population. Temporal estimates of both pedigree and microsatellite data showed a high, but decreasing level inbreeding. Through simulations, we estimated that the reintroduced population needs more than 100 individuals to retain approximately 90% of its current, already depauperate, genetic diversity. We have provided recommendations for the management program concerning introgressed genes from domestic horse and the number and origin of individuals for future reintroductions.

普氏野马（Przewalski's horse）于20世纪60年代中期在野外灭绝。1985年起，研究人员从西方动物园引入普氏野马个体至中国的两个繁育中心，并启动了繁育计划。随着圈养种群规模不断扩大，中国西北分别于2001年和2010年启动了两个普氏野马野化放归项目。目前针对中国境内普氏野马种群的遗传多样性研究仍较为有限，但相关成果可用于优化遗传管理工作，并评估野化放归项目的实施成效。据此，研究团队利用10个微卫星（microsatellite）位点，结合系谱数据，对1个放归种群与2个圈养种群开展了检测分析。研究结果显示，圈养种群的遗传多样性水平高于放归种群，提示在野化放归过程中可能丢失了部分等位基因。种群间检测到显著的遗传分化（FST=0.09±0.05，RhoST=0.05±0.02），贝叶斯聚类分析支持存在三个亚种群。圈养种群与放归种群间的遗传分化程度最高，且放归种群的近交系数普遍更高。基于系谱数据与微卫星数据的时间跨度近交水平估计结果均显示，近交水平曾处于较高水平但呈下降趋势。通过模拟实验，研究团队估算得出：若要保留当前已较为匮乏的遗传多样性中的约90%，放归种群的个体数量需超过100只。最后，研究团队针对家马（domestic horse）的渐渗基因（introgressed genes）管理方案，以及未来野化放归项目所需个体的数量与来源提出了针对性建议。