中国荷斯坦奶牛IL-8基因SNP-180A/G显著影响体细胞评分

摘要

[目的]通过研究IL-8基因5'侧翼区多态性与体细胞评分(somatic cell score,SCS)的相关性,获得与低体细胞计数(somatic cell counts,scc)性状相关的遗传标记,为低SCC性状的选育提供借鉴.[方法]采用PCR-SSCP技术检测来自30个公牛家系的610头中国荷斯坦奶牛的IL-8基因5'侧翼区的多态性,并采用混合动物模型分析多态位点与主要泌乳性状及SCS的相关性.[结果]IL-8基因5'侧翼区存在1个SNP位点,即-180 A/G;定义了3种基因型,即GG、GA和AA,频率分别为0.41、0.43和0.16.该SNP位点对SCS具有显著效应,对SCS指标来说,GG极显著低于GA或AA(P＜0.01),而该SNP位点对测定日产奶量、测定日乳脂率、测定日乳蛋白率和305 d校正产奶量的影响不显著(P＞0.05).[结论]IL-8基因5侧翼区SNP-180 A/G显著影响体细胞评分.%[Objective] Bovine interleukin-8 (IL-8) is one of the major factors recruiting neutrophils during cow mastitis and causing rapid increase of somatic cell counts (SCC). Knowledge of IL-8 polymorphisms would be helpful to genetic selection of low SCC. [Method] The SNPs in the 5' upstream of bovine IL-8 gene were investigated in 610 Chinese Holstein cows from 30 bull families in a dairy farm in Shanghai using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique, and milking traits and somatic cell score (SCS) were measured and their relationship was analyzed using a mixed animal model. [Result] The results showed that one SNP, A(-180)G, was detected, determining three genotypes, GG, GA and AA with frequencies of 0.41, 0.43 and 0.16, respectively. The SNP showed significant effect on SCS, with GG having a significantly lower SCS than GA or AA (P<0.01), while this SNP had no effect on test-day milk yield, test-day milk fat content, test-day milk protein content, and 305 d corrected milk yield. [Conclusion]The findings demonstrated that the SNP -180A/G exerted significant effect on SCS.