Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, Japan.
Gene. 2011 Feb 1;472(1-2):42-9. doi: 10.1016/j.gene.2010.10.007. Epub 2010 Oct 19.
In cattle, bovine leukocyte antigens (BoLAs) have been extensively used as markers for bovine diseases and immunological traits. In this study, we sequenced alleles of the BoLA class II loci, BoLA-DRB3 and BoLA-DQA1, from 650 Japanese cattle from six herds [three herds (507 animals) of Japanese Black cattle and three herds (143 animals) of Holstein cattle] using polymerase chain reaction-sequence-based typing (PCR-SBT) methods. We identified 26 previously reported distinct DRB3 alleles in the two populations: 22 in Japanese Black and 17 in Holstein. The number of DRB3 alleles detected in each herd ranged from 9 to 20. Next, we identified 15 previously reported distinct DQA1 alleles: 13 in Japanese Black and 10 in Holstein. The number of alleles in each herd ranged from 6 to 10. Thus, allelic divergence is significantly greater for DRB3 than for DQA1. A population tree on the basis of the frequencies of the DRB3 and DQA1 alleles showed that, although the genetic distance differed significantly between the two cattle breeds, it was closely related within the three herds of each breed. In addition, Wu-Kabat variability analysis indicated that the DRB3 gene was more polymorphic than the DQA1 gene in both breeds and in all herds, and that the majority of the hypervariable positions within both loci corresponded to pocket-forming residues. The DRB3 and DQA1 heterozygosity for both breeds within each herd were calculated based on the Hardy-Weinberg equilibrium. Only one Japanese Black herd showed a significant difference between the expected and observed heterozygosity at both loci. This is the first report presenting a detailed study of the allelic distribution of BoLA-DRB3 and -DQA1 genes in Japanese Black and Holstein cattle from different farms in Japan. These results may help to develop improved livestock breeding strategies in the future.
在牛中，牛白细胞抗原（BoLA）已被广泛用作牛疾病和免疫性状的标记物。在这项研究中，我们使用聚合酶链反应-序列基 因分型（PCR-SBT）方法对来自六个牛群（三个日本黑牛群[507 只动物]和三个荷斯坦牛群[143 只动物]）的 650 头日本牛的 BoLA 类 II 基因座 BoLA-DRB3 和 BoLA-DQA1 的等位基因进行了测序。我们在两个群体中鉴定了 26 个先前报道的不同 DRB3 等位基因：22 个在日本黑牛中，17 个在荷斯坦牛中。每个牛群检测到的 DRB3 等位基因数量从 9 到 20 不等。接下来，我们鉴定了 15 个先前报道的不同 DQA1 等位基因：13 个在日本黑牛中，10 个在荷斯坦牛中。每个牛群的等位基因数量从 6 到 10 不等。因此，DRB3 的等位基因分化明显大于 DQA1。基于 DRB3 和 DQA1 等位基因频率的种群树表明，尽管两个牛品种之间的遗传距离有显著差异，但在每个品种的三个牛群内，它们密切相关。此外，Wu-Kabat 变异性分析表明，在两个品种和所有牛群中，DRB3 基因比 DQA1 基因更具多态性，并且两个基因座中的大多数高变位置都对应于口袋形成残基。根据 Hardy-Weinberg 平衡，计算了每个牛群中两个品种的 DRB3 和 DQA1 杂合性。只有一个日本黑牛群在两个基因座上的预期和观察杂合性之间存在显著差异。这是首次报道日本不同农场的日本黑牛和荷斯坦牛 BoLA-DRB3 和-DQA1 基因的等位基因分布的详细研究。这些结果可能有助于未来制定更好的家畜育种策略。
