Goat milk casein proteins (αS1, αS2, β and κ) are encoded by four loci (CSN1S1, CSN1S2, CSN2 and CSN3, respectively) clustered within 250 kb in chromosome 6. In this study, 159 Murciano-Granadina goats were genotyped for 48 SNPs within the entire casein region. Phenotypes on milk yield and components were obtained from 2,594 dairy registries. Additive and dominance effects on milk composition and quality were studied using non-parametric tests and principal component analysis to prevent SNPs multicollinearity. Two deletions in exon 4 (CSN1S1 and CSN3), one in exon 7 (CSN2) and one in exon 15 (CSN1S2) have been found at frequencies ranging from 0.12 to 0.50. Bonferroni-corrected significant SNP additive and dominance effects were found for milk yield, fat, protein, dry matter and lactose, and somatic cells. Exons 15 and 7 were significantly associated with milk yield and components except for lactose and somatic cells, while exon 4 was significantly associated with milk yield and components except for protein and dry matter. SNPs' associations with somatic cells were less frequent and weaker than those with milk yield and components. As caseins increase, somatic cells decrease, reducing milk enzymatic activity and consumption suitability. Hence, including molecular information in breeding schemes may promote production efficiency, as selecting against undesirable alleles could prevent the compromises derived from their dominance effects.

中文翻译：

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酪蛋白复合 SNP 对 Murciano-Granadina 山羊牛奶含量和质量的加性和显性影响的非参数关联分析

山羊奶酪蛋白（αS1、αS2、β 和 κ）由聚集在 6 号染色体 250 kb 内的四个基因座（分别为 CSN1S1、CSN1S2、CSN2 和 CSN3）编码。在这项研究中，对 48 只 Murciano-Granadina 山羊进行了基因分型整个酪蛋白区域内的 SNP。从 2,594 个乳制品登记处获得产奶量和成分的表型。使用非参数检验和主成分分析来研究添加剂和显性效应对牛奶成分和质量的影响，以防止 SNP 多重共线性。外显子 4（CSN1S1 和 CSN3）中的两个缺失，外显子 7（CSN2）中的一个和外显子 15（CSN1S2）中的一个，频率范围为 0.12 到 0.50。在产奶量、脂肪、蛋白质、干物质和乳糖以及体细胞方面发现了经 Bonferroni 校正的显着 SNP 加性和优势效应。外显子 15 和 7 与牛奶产量和除乳糖和体细胞外的成分显着相关，而外显子 4 与除蛋白质和干物质外的牛奶产量和成分显着相关。SNP 与体细胞的关联比与产奶量和成分的关联更少且更弱。随着酪蛋白的增加，体细胞减少，从而降低牛奶酶活性和食用适宜性。因此，在育种计划中包括分子信息可能会提高生产效率，因为选择不受欢迎的等位基因可以防止由于其优势效应而产生的妥协。与体细胞的关联比与产奶量和成分的关联更不频繁，也更弱。随着酪蛋白的增加，体细胞减少，从而降低牛奶酶活性和食用适宜性。因此，在育种计划中包括分子信息可能会提高生产效率，因为选择不受欢迎的等位基因可以防止由于其优势效应而产生的妥协。与体细胞的关联比与产奶量和成分的关联更不频繁，也更弱。随着酪蛋白的增加，体细胞减少，从而降低牛奶酶活性和食用适宜性。因此，在育种计划中包括分子信息可能会提高生产效率，因为选择不受欢迎的等位基因可以防止由于其优势效应而产生的妥协。