Data from: Characterization of class I- and II-like major histocompatibility complex loci in pedigrees of North Atlantic right whales

North Atlantic right whales have one of the lowest levels of genetic variation at minisatellite loci, microsatellite loci, and mitochondrial control region haplotypes among mammals. Here, adaptive variation at the peptide binding region of class I and class II DRB-like genes of the major histocompatibility complex was assessed. Amplification of a duplicated region in 222 individuals revealed at least 11 class II alleles. Six alleles were assigned to the locus Eugl-DRB1 and 5 alleles were assigned to the locus Eugl-DRB2 by assessing segregation patterns of alleles from 81 parent/offspring pedigrees. Pedigree analysis indicated that these alleles segregated into 12 distinct haplotypes. Genotyping a smaller subset of unrelated individuals (n = 5 and 10, respectively) using different primer sets revealed at least 2 class II pseudogenes (with ≥ 4 alleles) and at least 3 class I loci (with ≥ 6 alleles). Class II sequences were significantly different from neutrality at peptide binding sites suggesting loci may be under the influence of balancing selection. Trans-species sharing of alleles was apparent for class I and class II sequences. Characterization of class II loci represents the first step in determining the relationship between major histocompatibility complex variability and factors affecting health and reproduction in this species.

北大西洋露脊鲸（North Atlantic right whales）是哺乳动物中，小卫星位点（minisatellite loci）、微卫星位点（microsatellite loci）以及线粒体控制区单倍型（mitochondrial control region haplotypes）遗传变异水平最低的类群之一。本研究对主要组织相容性复合体（major histocompatibility complex, MHC）I类与II类DRB样基因的肽结合区（peptide binding region）的适应性变异进行了评估。通过对222个个体的重复区域进行扩增，共检出至少11个II类等位基因。通过分析81个亲子代谱系的等位基因分离模式，将其中6个等位基因归属于Eugl-DRB1位点，剩余5个归属于Eugl-DRB2位点。谱系分析结果显示，这些等位基因可划分为12种不同的单倍型。使用不同引物组对两组较小的无关个体亚群（样本量分别为n=5和n=10）进行基因分型，结果检出至少2个II类假基因（pseudogenes，每个假基因包含≥4个等位基因）以及至少3个I类位点（每个位点包含≥6个等位基因）。II类序列在肽结合位点上显著偏离中性进化模式，提示相关位点可能受到平衡选择（balancing selection）的作用。I类与II类序列均呈现出明显的跨物种等位基因共享现象。对该物种II类位点的表征，是明确主要组织相容性复合体变异与该物种健康及繁殖相关影响因素之间关联的第一步。