Jann Oliver C, Ibeagha-Awemu Eveline M, Ozbeyaz Ceyhan, Zaragoza Pilar, Williams John L, Ajmone-Marsan Paolo, Lenstra Johannes A, Moazami-Goudarzi Katy, Erhardt Georg
Department for Animal Breeding and Genetics, Justus-Liebig University of Giessen, Germany.
Genet Sel Evol. 2004 Mar-Apr;36(2):243-57. doi: 10.1186/1297-9686-36-2-243.
The genetic diversity of the casein locus in cattle was studied on the basis of haplotype analysis. Consideration of recently described genetic variants of the casein genes which to date have not been the subject of diversity studies, allowed the identification of new haplotypes. Genotyping of 30 cattle breeds from four continents revealed a geographically associated distribution of haplotypes, mainly defined by frequencies of alleles at CSN1S1 and CSN3. The genetic diversity within taurine breeds in Europe was found to decrease significantly from the south to the north and from the east to the west. Such geographic patterns of cattle genetic variation at the casein locus may be a result of the domestication process of modern cattle as well as geographically differentiated natural or artificial selection. The comparison of African Bos taurus and Bos indicus breeds allowed the identification of several Bos indicus specific haplotypes (CSN1S1C-CSN2A2-CSN3AI / CSN3H) that are not found in pure taurine breeds. The occurrence of such haplotypes in southern European breeds also suggests that an introgression of indicine genes into taurine breeds could have contributed to the distribution of the genetic variation observed.
基于单倍型分析研究了牛酪蛋白基因座的遗传多样性。考虑到酪蛋白基因最近描述的遗传变异（迄今为止尚未成为多样性研究的主题），得以鉴定出新的单倍型。对来自四大洲的30个牛品种进行基因分型，揭示了单倍型的地理相关分布，主要由CSN1S1和CSN3等位基因频率决定。发现欧洲牛品种内部的遗传多样性从南到北、从东到西显著降低。酪蛋白基因座处牛遗传变异的这种地理模式可能是现代牛驯化过程以及地理差异的自然或人工选择的结果。对非洲瘤牛和印度瘤牛品种的比较，鉴定出了几种纯牛品种中未发现的印度瘤牛特异性单倍型（CSN1S1C-CSN2A2-CSN3AI / CSN3H）。这种单倍型在欧洲南部品种中的出现也表明，印度瘤牛基因渗入牛品种可能促成了所观察到的遗传变异分布。
