中国荷斯坦牛STAT5A基因遗传多态性与泌乳性状的相关分析

 【目的】研究STAT5A基因多态性与中国荷斯坦牛泌乳性状的相关性，为进一步加快育种进程提供参考依据。【方法】利用PCR-SSCP技术对279头中国荷斯坦牛的STAT5A基因的P1和P2两个位点进行群体遗传学检测；计算其基因频率和基因型频率，并对多态性与泌乳性状进行相关性分析。【结果】发现在STAT5AP1和STAT5AP2两个位点上分别存在3种多态以及7种单倍型组合。STAT5AP1位点的AA、GG和AG的基因型频率分别为0.2401、0.1470和0.6129，A和G的基因频率分别为0.5466和0.4534，不同基因型对第1胎产奶量、乳蛋白率和第2胎乳蛋白率存在显著影响；STAT5AP2位点的CC、TT和CT的基因型频率分别为0.7527、0.0036和0.2437，C和T的基因频率分别为0.8746和0.1254，不同基因型对第2胎乳蛋白率有显著影响；7种单倍型组合AACC、AGCC、AACT、AGCT、GGCT、GGCC和AATT的频率分别为0.1864、0.4624、0.0502、0.1505、0.0430、0.1039和0.0036，不同单倍型与第1和2胎产奶量以及乳蛋白率存在相关性。【结论】STAT5A基因不同基因型和单倍型组合与中国荷斯坦牛产奶量和乳蛋白率存在相关性，但与乳脂率不相关。

Polymorphisms of STAT5A Gene and Its Association with Milk Performance Traits in Chinese Holstein Cattle

PCR-SSCP was applied to analyze the polymorphisms of two locus in STAT5A gene in 279 Chinese Holstein cattle. Three genotypes were found at two locus and 7 haplotype combinations were present. The frequencies of genotype AA/BB/AB were 0.2401/0.1470/0.6129 and that of allele A/B in the population were 0.5466/0.4534 at locus P1. The result showed that the genotypes had significant effect on milk yield in the first lactations as also as protein rate in the second lactations. Genotype frequency of CC/DD/CD were 0.2401/0.1470/0.6129 and the frequencies of allele C/D in the population were 0.5466/0.4534 at locus P2. Different genotypes had remarkable influence on protein rate in the second lactations. In addition ,the frequencies of 7 haplotype combinations were 0.1864,0.4624,0.0502,0.1505,0.0430,0.1039 and 0.0036, different haplotype combinations affected milk yield, protein rate in the first and second lactations. No significant differences between individuals with different genotypes and haplotype combinations for milk fat rate in the first and second lactations at these two locus.