雌性秦岭川金丝猴配偶选择偏好的研究

Mate choice, often known as intersexual selection, is a behavioral process in which selection is dependent on the attractiveness of one or more phenotypic traits in one sex to individuals of the opposite sex. Mate choice is an important factor in the life history of individuals, and is an important research topic in behavioral ecology. In mammals, high costs of reproduction makes females the more choosy sex. The social structure of the golden snub-nosed monkey is a multi-level society centred on a large breeding band that is comprised of multiple one-male units. Males can obtain mates by attracting females rather than by competing with other males. In this process, the female has many opportunities to choose preferred mates. However, the overall significance of proactive female choice, and the criteria by which females choose males, remain unclear in this species. This project will use established methods based on individual recognization and long-term behavior observation, to define the behavior strategy of individuals using in determining the male-female relationship. We will then measure the major histocompatibility complex (MHC) genotype of each individual and the relatedness coefficient between males-females in already determined relationships. Furthermore, by integrating data on MHC genotype, relatedness and male-female relationships, to reveal the relationship between MHC genotype, relatedness coefficient and female mate choice behavior; then investigate the effects of MHC-based mate choice by females on maintaining genetic diversity in this species. The results will further our understanding of female mate choice in golden snub-nosed monkeys and other polygynous mammals, and will add to the biological knowledge of this endangered species thus helping promote its conservation.

配偶选择指动物通过评估异性的繁殖特征，选择最优配偶，共同传递基因，提高适合度的过程，是个体生活史中的关键环节；个体间围绕于此展开的繁殖竞争，也是物种在漫长的进化中获得新属性的主要动力之一。川金丝猴的社群，以类似家庭的一雄多雌社会单元为基础，雄性吸引异性组建后宫，并获得繁殖机会。在此过程中，雌性拥有选择配偶的主导权，但其配偶关系确立的具体行为学机制，基因传递及其影响因素仍不甚清楚。本项目以秦岭川金丝猴为研究对象，在长期行为学观察和个体识别的基础上，通过明确雌雄个体在确定配偶关系中的行为策略；结合亲子鉴定和MHC基因分型，分析亲缘关系以及MHC基因对雌性配偶选择倾向的影响，阐明雌性川金丝猴在配偶选择过程中的择偶机制，揭示雌性选择好基因配偶对维持种群遗传多样性的贡献，促进灵长类动物社会行为学相关理论的发展，为更好的保育川金丝猴这一濒危物种提供科学的指导。

配偶选择是择偶者通过评估异性的表型和行为，选择最优交配对象，并通过特定的择偶策略，提高自身适合度的繁殖机制。本项目以生活在一雄多雌制重层社会中的川金丝猴为研究对象，基于个体识别和长期的野外行为学观察，积累了大量研究群内个体间交配关系、生育记录，单元结构以及配偶变化的数据，结合实验室的MHC基因分型和微卫星基因分型，围绕雌性配偶选择的偏好开展研究，得到了以下研究成果。1. 在川金丝猴配偶选择的基因偏好方面，发现雌性在选择子代的生父时偏好MHC多样性更高且与自身MHC基因中度相异的雄性；此外，与随机雄性相比，雌性在选择社会配偶及子代的生父时，更偏好拥有等位基因Rhro-DQA1*05和Rhro-DQB1*08的雄性，支持了配偶选择的好基因假说。2. 在川金丝猴配偶选择的年龄偏好方面，发现与其他年龄段雄性相比，壮年雄性（10-15岁）更有可能成为OMU主雄。雄性7-8岁时逐渐开始拥有后宫，12岁左右时雌性数量达到顶峰，此后则呈现出下降的趋势。并且，雌性选择社会配偶和单元外交配对象时采取不同的选择策略，即雌性在进行单元外交配时倾向于选择高等级壮年雄性，却偏好迁移到低等级却年轻的雄性。3. 在川金丝猴的适应性变异方面，发现尽管经历了严重的瓶颈效应和种群衰退，该物种依然保留了较高的适应性遗传变异（MHC-DRB：average HE = 0.626, PIC = 0.583）。基因多样性和种群分化模式，正选择和跨物种进化均证实了病原体介导的平衡选择维持了MHC-DRB基因的适应性变异现状。本项目在探索机制研究的过程中，还开发了重复位点的基因分型方法，为利用重复位点进行种群遗传学分析提供了实用的计算工具。这些成果促进了灵长类动物社会行为学相关理论的发展，为更好的保育川金丝猴这一濒危物种提供了科学的指导。