Data from: Diversity of MHC DQB and DRB genes in the endangered Australian sea lion (Neophoca cinerea)

Major histocompatibility complex (MHC) class II molecules have an important role in vertebrate adaptive immunity, being responsible for recognizing, binding, and presenting specific antigenic peptides to T lymphocytes. Here, we study the MHC class II DQB and DRB exon 2 genes of the Australian sea lion (Neophoca cinerea), an endangered pinniped species that experiences high pup mortality. Following characterization of N. cinerea DQB and DRB by molecular cloning, and evaluation of diversity in pups across 2 colonies using variant screening (n = 47), 3 DQB alleles and 10 DRB variants (including 1 pseudogene allele) were identified. The higher diversity at DRB relative to DQB is consistent with other studies in marine mammals. Despite overall lower MHC class II allelic diversity relative to some other pinniped species, we observed similar levels of nucleotide diversity and selection in N. cinerea. In addition, we provide support for recent divergence of MHC class II alleles. The characterization of MHC class II diversity in the Australian sea lion establishes a baseline for further investigation of associations with disease, including endemic hookworm infection, and contributes to the conservation management of this species.

主要组织相容性复合体（Major histocompatibility complex, MHC）II类分子在脊椎动物适应性免疫中发挥核心作用，负责识别、结合并将特异性抗原肽呈递给T淋巴细胞。本研究以幼崽死亡率极高的濒危鳍足类物种澳洲海狮（Neophoca cinerea）的MHC II类DQB与DRB外显子2基因展开探究。研究团队通过分子克隆技术鉴定澳洲海狮的DQB与DRB基因，并采用变异筛查法对2个种群的47份幼崽样本的基因多样性进行评估，最终共鉴定出3个DQB等位基因与10个DRB变异体（含1个假基因等位基因）。相较于DQB基因座，DRB基因座的多样性水平更高，这与其他海洋哺乳动物的相关研究结论一致。尽管相较于部分其他鳍足类物种，澳洲海狮的MHC II类等位基因整体多样性偏低，但本研究仍在该物种中观测到相似水平的核苷酸多样性与选择压力。此外，本研究为MHC II类等位基因的近期分化提供了实证支持。对澳洲海狮MHC II类多样性的系统性鉴定，为后续探究其与包括地方性钩虫感染在内的多种疾病的关联奠定了研究基线，并为该物种的保护管理工作提供了重要依据。