大熊猫（Ailuropoda melanoleuca）是我国特有的珍稀动物，现被IUCN红色名录列为易危物种。迁地保护和人工繁育对大熊猫种群恢复发挥了重要作用。在圈养大熊猫的人工繁殖中，目前通用的方法是依据雌雄个体对种群的遗传贡献大小，计算交配适宜度指数（mate suitability index, MSI）并以此制定配对计划。然而，目前尚无任何证据证明该计划是否符合大熊猫的择偶偏好。

对于大熊猫择偶偏好的遗传学机制，以往有两项研究分别从野外采样和圈养谱系入手分析了大熊猫基于主要组织相容性复合体（major histocompatibility complex, MHC）基因的择偶偏好，但所得到的结果互相矛盾，且两项研究均未能从行为层面进行实验。因此，通过验证MSI指数与大熊猫嗅觉介导的择偶偏好的关系，并从行为层面和遗传学层面相结合的角度探究大熊猫的择偶机制，具有重要理论和实践意义。

本论文以中国大熊猫保护研究中心的圈养大熊猫作为研究对象，在观察其配偶选择行为的基础上，完成了以下工作：1）研究雌性大熊猫对雄性大熊猫气味的选择偏好是否能够被MSI指数所预测；2）选择MHC II基因的DQA1、DQA2、DQB1和DRB3位点，探究雌性大熊猫在行为实验中表现出偏好的雄性气味供体MHC II基因多态性、杂合度以及互补程度对配偶选择的影响。主要研究结果如下：

（1）对14只雌性大熊猫进行气味选择偏好的two-choice实验发现，雌性大熊猫对不同MSI指数的雄性大熊猫气味源的探究总时长、总探究次数、嗅闻次数和接触探究次数与雄性的MSI指数均无显著相关关系；进一步通过Wilcoxon检验，发现雌性个体对高和低MSI组来源的雄性大熊猫气味，在探究总时长、探究总次数、嗅闻次数和接触探究次数均无显著差异。

（2）通过对雌雄大熊猫个体MHC II基因测序结果进行比对分析，获得了各个体在MHC II基因上的等位基因频率、杂合度、雌雄个体间共享的等位基因数、雌雄个体间的氨基酸进化距离和氨基酸功能距离等各项参数。通过蒙特卡洛方法进行随机抽样模拟，发现雌性大熊猫未表现出对MHC II基因上具有较高等位基因频率和较高杂合度雄性的偏好，结果不支持“好基因”假说和杂合子优势假说；但模拟结果显示，雌性大熊猫表现出了对具有更少MHC II共享等位基因、较大氨基酸进化距离和氨基酸功能距离的雄性个体的选择偏好，表明雌性大熊猫的择偶行为支持非选型交配假说。

The giant panda (Ailuropoda melanoleuca) is an endemic species to China and is currently listed as a vulnerable species on the IUCN Red List. Ex-situ conservation and artificial breeding are crucial to the recovery of giant panda population. In the artificial insemination of captive giant pandas, the current method is to calculate the MSI index according to the genetic contribution of the mating pandas, and to guide mate pre-selection according by MSI index. However, there’s no evidence prove that the MSI can match the panda’s mating preference at the behavioral level.

As for the genetic basis of giant panda's mate choice, there have been a few studies to analyze MHC gene dependence of mate selection preference from field sampling and captive pedigree, but the results obtained are conflicting and have not been verified from the behavioral level. Therefore, it is of great significance to protect this species by verifying if the MSI index can predict the giant panda's mating preference and exploring the mate selection mechanism of giant pandas by combining behavioral and genetic evidence.

This paper researched on the captive giant panda of China Conservation and Research Center for Giant Panda (CCRCGP), and the following work is completed based on observing its behavior: 1) studying whether female giant panda's preference for male giant panda odor can be predicted  by MSI index; 2) selecting DQA1, DQA2, DQB1 and DRB3 sites of MHC II gene, and exploring the influence of MHC II gene polymorphism, heterozygosity and compatibility of male odor donor preferred by female giant panda on mate selection in behavioral experiments.

The role of the MSI index in spouse selection behavior was verified and the mechanism of giant panda's spouse selection behavior was revealed. The main results are as follows:

(1) 14 female giant pandas were tested by two-choice experiments on odor selection preference. The results are that the Spearman test of female giant pandas there’s no significant correlation between the total duration, the total frequency of exploration, the frequency of sniffs and the frequency of contact exploration and the male pandas’ MSI index; The Wilcoxon test of female giant pandas there’s no significant correlation between the total duration, the total frequency of exploration, the frequency of sniffs and the frequency of contact exploration on male giant pandas in different MSI groups showed that there was no significant difference in all parameters between the two groups.

(2) By analyzing the MHC II gene of the giant panda, allele frequency, heterozygosity, number of sharing allele between male and female individuals, evolutionary amino acid distance, and functional amino acid distance between male and female individuals are obtained. The Monte Carlo method was used to carry out random resampling simulations. It was found that female giant pandas did not show preference for males with higher MHC II allele frequency and higher heterozygosity, which did not support the "good gene" hypothesis and heterozygosity hypothesis. However, female giant pandas show preference for males with fewer MHC II shared alleles, larger evolutionary amino acid distance, and larger functional amino acid distance, indicating that female giant pandas' mate selection behavior supports the disassortative hypothesis.