Noce A, Pazzola M, Dettori M L, Amills M, Castelló A, Cecchinato A, Bittante G, Vacca G M
Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100, Sassari, Italy.
Department of Animal Genetics, Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Campus Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain.
Anim Genet. 2016 Dec;47(6):717-726. doi: 10.1111/age.12474. Epub 2016 Jul 20.
Regulatory variation at the ovine casein genes could have important effects on the composition and coagulation properties of milk. Herewith, we have partially resequenced the promoters and the 3'-UTR of the four casein genes in 25 Sarda sheep. Alignment of these sequences allowed us to identify a total of 29 SNPs. This level of polymorphism (one SNP every 250 bp) is remarkably high if compared with SNP densities estimated in human genic regions (approximately one SNP per bp). The 29 SNPs identified in our resequencing experiment, plus three previously reported SNPs mapping to the lactalbumin, alpha (LALBA) and β-lactoglobulin (BLG, also known as progestagen-associated endometrial protein, PAEP) genes, were genotyped with a multiplex TaqMan Open Array Real-Time PCR assay in 760 Sarda sheep with records for milk composition and coagulation properties. Association analysis revealed the existence of significant associations of CSN1S2 and CSN3 genotypes with milk protein and casein contents. Moreover, genotypes at CSN1S1 were significantly associated with rennet coagulation time, curd firming time and curd firmness, whereas CSN2 was associated with curd firming time. These results suggest that SNPs mapping to the promoters and 3'-UTRs of ovine casein genes may exert regulatory effects on gene expression and that they could be used for improving sheep milk quality and technological traits at the population level through marker assisted selection.
绵羊酪蛋白基因的调控变异可能对牛奶的成分和凝固特性产生重要影响。在此，我们对25只撒丁岛绵羊的4个酪蛋白基因的启动子和3'-UTR进行了部分重测序。这些序列的比对使我们总共鉴定出29个单核苷酸多态性（SNP）。与人类基因区域估计的SNP密度（每bp约一个SNP）相比，这种多态性水平（每250 bp一个SNP）非常高。在我们的重测序实验中鉴定出的29个SNP，加上之前报道的3个映射到乳白蛋白α（LALBA）和β-乳球蛋白（BLG，也称为孕激素相关子宫内膜蛋白，PAEP）基因的SNP，在760只具有牛奶成分和凝固特性记录的撒丁岛绵羊中，通过多重TaqMan开放式阵列实时PCR分析进行基因分型。关联分析揭示了CSN1S2和CSN3基因型与乳蛋白和酪蛋白含量之间存在显著关联。此外，CSN1S1的基因型与凝乳酶凝固时间、凝乳形成时间和凝乳硬度显著相关，而CSN2与凝乳形成时间相关。这些结果表明，映射到绵羊酪蛋白基因启动子和3'-UTR的SNP可能对基因表达产生调控作用，并且它们可用于通过标记辅助选择在群体水平上改善绵羊奶质量和技术特性。
