动物如何有效的识别病原体以抵御疾病的发生是其生存过程中面临的重要挑战。主要组织相容性复合体（Major Histocompatibility Complex, MHC）是广为知晓的与抗原识别、激活免疫系统密切相关的重要基因家族，因其在动物存活与繁殖过程中的关键性作用直接关系到个体的适合度，MHC基因多样性的产生与维持机制已成为近年来动物适应性进化与分子生态学研究关注的热点问题。本项目拟利用二代测序技术，以基因组SNPs作为中性分子标记重建灰眉岩鹀不同地理种群的历史动态，并在控制环境异质性的基础上，检验血液寄生虫选择压力下，平衡选择、波动选择和遗传漂变效应如何驱动灰眉岩鹀MHC-IIB基因多样性的产生与维持？从而更为全面地了解和认知鸟类MHC基因多样性与寄生虫感染的关系，揭示鸟类MHC-II类基因多样性产生与维持的适应性进化机制。

Pathogen recognition is a big challenge to the animals for survival. The Major Histocompatibility Complex (MHC) comprises a family of genes that play a crucial role in the adaptive immune system to recognize pathogens and trigger the adaptive immune response. Due to its importance for animals in survival and breeding, the polymorphism level of MHC is stronly related the fitness of animals. Thus, how the diversity of MHC is produced and maintained has became a hotspot recently in adaptive evolutionary research. This project attend to utilize the next generation sequencing tecniques to identify genomic neutral SNPs to reconstruct the demographic history of widespread geographic populations in Godlewski's Bunting, in order to test the relative importance of parasite-mediated selection (balancing selection or fluctuation selection) and neutral genetic drift in shaping the diversity of MHC-IIB genes.