Walawski Krzysztof, Czarnik Urszula
Department of Animal Genetics, University of Warmia and Mazury in Olsztyn, ul. M.Oczapowskiego 5, 10-957 Olsztyn, Poland.
J Appl Genet. 2003;44(2):191-5.
The study was carried out in a Polish Black-and-White cattle population, represented by 167 AI sires, 200 young tested bulls, 190 bull-dams, and 606 randomly chosen cows from commercial herds. The fragment of the bovine prion protein gene (PRNP) coding the octapeptide-repeat sequence, was identified by PCR analysis. Two different gene variants of 349 bp and 373 bp in size, produced three genotypes: PRNP 6/6, PRNP 6/5 and PRNP 5/5, respectively. Allele frequency in all examined populations, on average 0.894 for PRNP 6 and 0.106 for PRNP 5, shows a significant difference between the group of cows from commercial herds, characterised by high frequency of PRNP 5 (q = 0.137) in comparison to AI sires (q = 0.077), young tested bulls (q = 0.052) and bull-dams (q = 0.084). Moreover, both analysed female groups of bull-dams and cows from commercial herds are distinguished by the presence of PRNP 5/5 homozygous animals, which were not recorded in the AI sires and young tested bulls, and had never been recognised in earlier examined Holstein-Friesian populations. Analysis of the genetic equilibrium indicates a very high conformity between observed and expected number of animals in the separate PRNP genotype groups. However, some tendency of difference is observed in highly selected cows, qualified as bull-dams on the basis of very high level of milk performance traits.
该研究在波兰黑白花牛群体中进行，该群体由167头人工授精公牛、200头青年测试公牛、190头公牛的母亲以及606头从商业牛群中随机挑选的母牛组成。通过聚合酶链反应（PCR）分析鉴定了牛朊病毒蛋白基因（PRNP）编码八肽重复序列的片段。两种大小分别为349 bp和373 bp的不同基因变体产生了三种基因型：分别为PRNP 6/6、PRNP 6/5和PRNP 5/5。在所有检测群体中，PRNP 6的等位基因频率平均为0.894，PRNP 5的等位基因频率为0.106，结果显示，与人工授精公牛（q = 0.077）、青年测试公牛（q = 0.052）和公牛的母亲（q = 0.084）相比，商业牛群中的母牛群体以PRNP 5的高频率（q = 0.137）为特征。此外，所分析的公牛的母亲和商业牛群中的母牛这两个雌性群体的特点是存在PRNP 5/5纯合动物，而在人工授精公牛和青年测试公牛中未记录到这种情况，并且在早期检测的荷斯坦 - 弗里生群体中也从未发现过。遗传平衡分析表明，在单独的PRNP基因型组中，观察到的动物数量与预期数量非常吻合。然而，在根据非常高的产奶性能特征被认定为公牛的母亲的高度选育母牛中，观察到了一些差异趋势。
