Lau Quintin, Chow Natalie, Gray Rachael, Gongora Jaime, Higgins Damien P
From the Faculty of Veterinary Science, The University of Sydney, B14 McMaster Building, Camperdown, New South Wales 2006, Australia.
J Hered. 2015 Jul-Aug;106(4):395-402. doi: 10.1093/jhered/esv022. Epub 2015 Apr 23.
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（MHC）II类分子在脊椎动物适应性免疫中发挥着重要作用，负责识别、结合并向T淋巴细胞呈递特定的抗原肽。在此，我们研究了澳大利亚海狮（Neophoca cinerea）的MHC II类DQB和DRB外显子2基因，这是一种濒危的鳍足类动物，幼崽死亡率很高。通过分子克隆对澳大利亚海狮的DQB和DRB进行特征分析，并使用变异筛选（n = 47）评估了两个群体幼崽的多样性，共鉴定出3个DQB等位基因和10个DRB变异体（包括1个假基因等位基因）。相对于DQB，DRB具有更高的多样性，这与其他海洋哺乳动物的研究结果一致。尽管相对于其他一些鳍足类物种，MHC II类等位基因的总体多样性较低，但我们在澳大利亚海狮中观察到了相似水平的核苷酸多样性和选择。此外，我们为MHC II类等位基因的近期分化提供了支持。澳大利亚海狮MHC II类多样性的特征分析为进一步研究其与疾病（包括地方性钩虫感染）的关联奠定了基础，并有助于该物种的保护管理。
