Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany.
Heredity (Edinb). 2011 Aug;107(2):115-26. doi: 10.1038/hdy.2010.173. Epub 2011 Jan 19.
Genes of the major histocompatibility complex (MHC) have a crucial role in the immune response of vertebrates, alter the individual odour and are involved in shaping mating preferences. Pathogen-mediated selection, sexual selection and maternal-fetal interactions have been proposed as the main drivers of frequently observed high levels of polymorphism in functionally important parts of the MHC. Bats constitute the second largest mammalian order and have recently emerged as important vectors of infectious diseases. In addition, Chiroptera are interesting study subjects in evolutionary ecology in the context of olfactory communication, mate choice and associated fitness benefits. Thus, it is surprising that they belong to the least studied mammalian taxa in terms of their MHC diversity. In this study, we investigated the variability in the functionally important MHC class II gene DRB, evidence for selection and population structure in the group-living lesser bulldog bat, Noctilio albiventris, in Panama. We found a single expressed, polymorphic Noal-DRB gene. The substitution pattern of the nucleotide sequences of the 18 detected alleles provided evidence for positive selection acting above the evolutionary history of the species in shaping MHC diversity. Roosting colonies were not genetically differentiated but females showed lower levels of heterozygosity than males, which might be a sign that the sexes differ in the selection pressures acting on the MHC. This study provides the prerequisites for further investigations of the role of the individual MHC constitution in parasite resistance, olfactory communication and mate choice in N. albiventris and other bats.
主要组织相容性复合体 (MHC) 的基因在脊椎动物的免疫反应中起着至关重要的作用，改变个体气味，并参与塑造交配偏好。病原体介导的选择、性选择和母婴相互作用被认为是 MHC 功能重要部分频繁观察到的高水平多态性的主要驱动因素。蝙蝠构成了第二大哺乳动物目，最近已成为传染病的重要载体。此外，在嗅觉通讯、配偶选择和相关适应度利益方面，翼手目是进化生态学中有趣的研究对象。因此，令人惊讶的是，就 MHC 多样性而言，它们属于研究最少的哺乳动物类群。在这项研究中，我们研究了巴拿马群体生活的小褐蝠 Noctilio albiventris 中功能重要的 MHC 类 II 基因 DRB 的变异性、选择证据和种群结构。我们发现了一个单一表达的、多态的 Noal-DRB 基因。检测到的 18 个等位基因的核苷酸序列取代模式为 MHC 多样性塑造的物种进化历史之上的正选择提供了证据。栖息的殖民地在遗传上没有分化，但雌性的杂合度低于雄性，这可能表明在 MHC 上作用的选择压力在两性之间存在差异。这项研究为进一步研究 N. albiventris 和其他蝙蝠个体 MHC 构成在寄生虫抗性、嗅觉通讯和配偶选择中的作用提供了前提条件。
