圈养大熊猫冷冻精液对其种群遗传多样性的作用

The effect of frozen semen of captive giant pandas on their population genetic diversity

在过去34年的圈养大熊猫种群保护工作中,我们成功建立了全球最大的大熊猫精子库,目前已保存50只大熊猫个体总计7000余支细管冷冻精液(冻精)。冷冻精液一方面可以使物种的遗传资源得到长久保存,另一方面可以通过人工授精的方式促进种群繁育。但是,圈养大熊猫冷冻精液对其种群遗传多样性的作用尚未有明确报道。本研究首先根据成都大熊猫繁育研究基地2000—2014年冷冻精液人工授精数据,对比分析了冻精人工授精个体和圈养种群的遗传多样性。结果显示,冻精人工授精个体遗传多样性均高于同年圈养种群的平均遗传多样性,表明在繁殖年份中冻精人工授精可以显著提高圈养大熊猫种群的遗传多样性。统计精子库中所有冻精个体的平均血缘系数并与圈养种群进行对比分析,探究冷冻精液对圈养种群遗传多样性的潜在作用。结果显示,精子库中有21只已死亡个体的精液,其中有66.67%的个体平均血缘系数低于圈养种群;有14只20岁以上个体的精液,其中有50.00%的个体平均血缘系数低于圈养种群;另有15只20岁以下个体的精液,其中有53.33%的个体平均血缘系数低于圈养种群,表明冷冻精液对圈养种群遗传多样性的保护具有重要价值。综上所述,冷冻精液不但有效保存了大熊猫遗传资源,而且在保护圈养种群遗传多样性方面具有积极的促进作用。

In the past 34 years of captive giant panda population protection,we have successfully established the world’s largest giant panda sperm bank,which has preserved a total of 50 giant panda individuals with more than 7000 straws of from zen semen.On one hand,frozen semen can preserve the genetic resources of the species for a long time.On the other hand,it can promote population reproduction through artificial insemination(AI).However,the role of frozen semen of captive giant pandas in their population genetic diversity has not been clearly reported.This study firstly analyzed the frozen semen AI data from 2000 to 2014 in Chengdu Research Base of Giant Panda Breeding,and compared the genetic diversities of frozen semen individuals and the captive population.The results showed that the genetic diversities of frozen semen individuals were higher than the captive population in the same breeding year,indicating that frozen semen AI can significantly improve the genetic diversity of the captive giant panda population in the breeding year.Secondly,the mean kinship(mK)of all frozen semen individuals in the sperm bank were calculated and compared with the captive population to explore the potential effect of frozen semen on the genetic diversity of the captive population.The results showed that the sperm bank conserved 21 dead individuals,of which 66.67%individuals had a lower mK than the captive population.There were 14 semen from surviving individuals over 20 years old,of which 50.00%individuals had a lower mK than the captive population.There were 15 surviving individuals under 20 years old,of which 53.33%individuals had a lower mK than the captive population.This result indicated that frozen semen has a great value in protecting the genetic diversity of the captive population.In conclusion,frozen semen not only effectively preserved the genetic resources of giant pandas but also played a positive role in protecting the genetic diversity of the captive population.