Laboratory of Animal Nutrition, Department of Animal Science, Faculty of Agriculture, Tokyo University of Agriculture, Atsugi, Japan.
Anim Sci J. 2021 Jan-Dec;92(1):e13644. doi: 10.1111/asj.13644.
The aim of this study was to investigate beta-casein polymorphism among 320 Japanese cows sampled from eight dairy farms. We used a newly-developed genotyping method that involved collecting DNA from hairs and a Cycleave polymerase chain reaction (PCR) assay to detect the A1, A2, and B variants. Results revealed the presence of five genotypes (A1A1, A2A2, A1A2, A1B, and A2B). We found that the most common genotype was A2A2 (0.42), followed by A1A2 (0.39) and A1A1 (0.11). The A1B and A2B genotypes were less frequent (<0.05). The frequencies of alleles A1, A2, and B were calculated to be 0.32, 0.64, and 0.04, respectively. Our study is the first to show the current status of beta-casein polymorphisms in Japanese dairy farms. Given the adverse effects of A1 beta-casein on human health, attempts have been made to develop herds consisting solely of A2A2 cows. Our study provides a reference for improving cow populations in Japanese dairy farms. The Cycleave PCR-based assay we developed here can be used for rapid and reliable genotyping of bovine beta-casein.
本研究旨在调查从 8 个奶牛场采集的 320 头日本奶牛的β-酪蛋白多态性。我们使用了一种新开发的基因分型方法，该方法涉及从毛发中收集 DNA 并进行 Cycleave 聚合酶链反应（PCR）检测来检测 A1、A2 和 B 变体。结果显示存在五种基因型（A1A1、A2A2、A1A2、A1B 和 A2B）。我们发现最常见的基因型是 A2A2（0.42），其次是 A1A2（0.39）和 A1A1（0.11）。A1B 和 A2B 基因型较少（<0.05）。等位基因 A1、A2 和 B 的频率分别计算为 0.32、0.64 和 0.04。本研究首次展示了日本奶牛场β-酪蛋白多态性的现状。鉴于 A1β-酪蛋白对人类健康的不利影响，人们试图开发仅由 A2A2 奶牛组成的牛群。本研究为改善日本奶牛场的牛群提供了参考。我们在这里开发的基于 Cycleave PCR 的检测方法可用于快速可靠地对牛β-酪蛋白进行基因分型。
