DISSERTATION RESEARCH: Immunogene Mediated Mate Choice in Populations of Peromyscus spp. Rodents with Different Mating Systems

几个世纪以来，动物如何选择配偶这个基本问题一直吸引着生物学家。今天，科技的发展使我们在择偶方面的知识突破了极限。最近的研究支持了一组特殊的基因，即主要组织相容性复合体（MHC）基因，在择偶过程中起着关键作用。MHC基因在脊椎动物中普遍存在，在适应性免疫系统中起着重要作用。在哺乳动物中，mhc基因型或“谱”通过尿液传播。这使得同种异体能够根据其免疫基因组成来识别和选择个体。理论预测，如果一个人根据MHC选择伴侣，他们应该更喜欢那些与自己MHC互补的人。这样，他们的后代将有更高的MHC多样性和/或免疫能力的提高。本项目探讨了被认为影响病原体暴露的两个因素的差异——交配行为（例如，一夫一妻制与滥交）和种群密度——如何影响动物在择偶过程中如何使用MHC。MHC和配偶选择的研究在保护和圈养繁殖计划中有重要的应用，它们可以帮助确定保持多样性和提高存活率的最佳策略。提高对MHC变异的功能和进化的理解也对人类健康具有重要意义，因为这些基因是我们对病原体适应性反应的基础。传统上，基于mhc的配偶选择研究使用了近亲繁殖的实验室动物，虽然有少数研究调查了野生种群，但它们仅限于对少数mhc位点的研究。这些限制在很大程度上是由于MHC的复杂性和以前可用的分子技术。因此，对不同位点和/或物种的研究得出了相互矛盾的结果。本项目旨在通过使用Next Generation Sequencing技术研究不同交配制度下自由生活的peromyscine啮齿动物中所有转录的MHC和非MHC免疫基因，从而全面了解免疫遗传变异与生殖行为模式之间的关系。特别强调的是理解免疫遗传变异和免疫基因的选择在不同的交配系统中是如何不同的。此外，该项目将探索生态变化，特别是密度变化如何影响基于免疫基因的配偶选择决策。了解个人层面的决定如何与群体层面的动态相互作用，将有助于理解自然环境中作用于免疫系统的选择压力。提出的分子方法是新颖的，可以应用于对最小化侵入性采样感兴趣的广泛研究。实地记录、行为观察、诱捕数据、摄影和GPS数据以及生物样本将提供给MVZ的收集，从而在一个在线数据库中可供感兴趣的研究人员使用。该项目产生的所有DNA序列数据将在通过GenBank发布后公开提供。

The fundamental question of how animals choose mates has fascinated and intrigued biologists for centuries. Today, technological and scientific developments make it possible to push the limits of our knowledge in the field of mate choice. Recent research has generated support for a particular group of genes, the Major Histocompatibility Complex, or MHC genes, as key players during mate selection. MHC genes are ubiquitous in vertebrates and play a major role in the adaptive immune system. In mammals, MHC-genotypes, or "profiles," are communicated via urine. This allows conspecifics to identify and choose individuals based on their immunogenetic makeup. Theory predicts that if individuals are selecting mates based on MHC, they should prefer those who complement their own MHC profile. In this way, their offspring will have higher MHC diversity and/or improved immunocompetence. This project explores how differences in two factors thought to affect exposure to pathogens -- mating behavior (e.g., monogamy versus promiscuity) and population density -- influence how animals use MHC during mate choice. Studies on MHC and mate choice have important applications to conservation and captive breeding programs, where they may help determine the best strategies for maintaining diversity and improving survival. Improved understanding of the function and evolution of MHC variation also has important implications for human health, since these are the genes that underlie our adaptive response to pathogens. Traditionally, MHC-based mate choice studies have used inbred lab animals, and while a few have examined wild populations, they have been limited to the study of only a few MHC-loci. These constraints are in large part due to MHC complexity and previously available molecular techniques. As a consequence, studies on different loci and/or species have yielded contradictory results. This project aims to generate a comprehensive understanding of the relationships between immunogenetic variation and patterns of reproductive behavior by using Next Generation Sequencing techniques to study all transcribed MHC and non-MHC immunogenes in free-living peromyscine rodents with different mating systems. Special emphasis is directed towards understanding how immunogenetic variation and selection on immunogenes differ with mating system. Further, this project will explore how changes in ecology, particularly density, influence mate choice decisions based on immunogenes. Understanding how individual-level decisions interact with population level dynamics should facilitate understanding of the selective pressures acting on the immune system in natural settings. The molecular methods proposed are novel and can be applied to a wide range of studies interested in minimizing invasive sampling. Field notes, behavioral observations, trapping data, photographic and GPS data, and biological samples will be contributed to the MVZ collections, thus accessible in an online database and available to interested researchers. All DNA sequence data resulting from this project will be made publicly available after publication through GenBank.