中国荷斯坦牛CXCR1基因遗传多态性与体细胞评分的关联分析

【目的】研究中国荷斯坦奶牛CXCR1基因的多态性及其与体细胞评分(Somaticcellscore,SCS)的关系,寻找与中国荷斯坦牛SCS相关的分子遗传标记,加快抗病育种进程。【方法】采用PCR-SSCP技术对来自30个公牛家系的610头中国荷斯坦牛CXCR1基因进行多态性检测,利用最小二乘均数法对CRCR1基因的多态位点与SCS进行相关分析,利用PHASE软件对4个多态位点进行单倍型分析。【结果】检测到4个SNPs,在5侧翼区发现了3个SNPs(-1830(A/G)、-1768(T/A)、-344(T/C)),在编码区783(C/A)位点为新发现的SNP。-1830(A/G)位点AA基因型个体SCS极显著低于AG基因型个体(P0.01),-1768(T/A)位点TT基因型个体SCS极显著低于TA基因型个体(P0.01),-344(T/C)位点TT基因型个体SCS极显著低于TC、CC个体(P0.01)。783(C/A)位点基因型个体的SCS差异不显著。单倍型Haplo2(ATTA)纯合基因型的SCS极显著低于Haplo1(ATCA)、Haplo3(GACA)和Haplo4(GATA)单倍型纯合基因型(P0.01)。【结论】-1830(A/G)位点AA基因型、-1768(T/A)位点TT基因型和-344(T/C)位点TT基因型以及单倍型Haplo2(ATTA)纯合体对中国荷斯坦牛的SCS具有较大的遗传效应,可作为分子标记应用于奶牛乳房炎抗性的筛选。

Genetic Polymorphism of CXCR1 Gene and Its Associations with Somatic Cell Score in Chinese Holstein

【Objective】 The polymorphism of CXCR1 gene and their correlation with somatic cell score(SCS) in Chinese Holstein cattle was analyzed for the purpose of providing molecular markers in the marker-assisted selections (MAS) to accelerate the disease-resistant breeding progress in Chinese Holstein cattle. 【Method】 The polymorphism of CXCR1 gene was detected by polymerase chain reaction-single strand comformation polymorphism (PCR-SSCP) technique in 610 Chinese Holstein cattle from 30 bull families.The association between polymorphic sites of CXCR1 gene and SCS was analyzed by the least square mean analysis, and the PHASE software was used as haplotype analysis 【Result】 Four SNPs were found, three SNPs (-1830(A/G), -1768(T/A), -344(T/C))were found in 5ˊflanking region, SNP 783(C/A) was reported in the coding region for the first time. At -1830(A/G) site, AA genotype had greatly significantly lower SCS than AG genotype (P＜0.01), at -1768(T/A) site, TT genotype had greatly significantly lower SCS than TA genotype (P＜0.01), at -340(T/C) site, TT genotype had greatly significantly lower SCS than TC and CC genotypes (P＜0.01). There were no significant differences in SCS among two genotypes at 783(C/A) site. The SCS of Haplo2(ATTA) haplotype homozygous genotype was significantly lower than that of Haplo1(ATCA), Haplo3(GACA) and Haplo4(GATA) haplotype homozygous genotypes (P＜0.01). 【Conclusion】 AA genotype at -1830(A/G) site, TT genotype at -1768(T/A) site, TT genotype at -344(T/C) site and Haplo2(ATTA) haplotype homozygous individuals had a great genetic effect on SCS in Chinese Holstein cattle, which can be used as candidate markers for mastitis resistance selection in dairy cattle.