中国荷斯坦牛转铁蛋白基因SNPs的检测及其与产奶性能的关系

 【目的】筛查转铁蛋白（transferrin，Tf）基因的多态性并分析其与中国荷斯坦牛产奶和健康性状的关联性，为未来培育高产优质健康奶牛提供可用的分子标记。【方法】采用DNA测序、PCR-RFLP和CRS-PCR技术，对576头中国荷斯坦牛转铁蛋白基因的多态性进行研究，运用SAS 软件分析其与乳品质和乳腺炎性状的关联性。【结果】在Tf基因5´调控区、外显子8和内含子8处发现了g.-1748G＞A、g.13942T＞C和g.14037A＞G共3个新的SNPs；关联分析表明，g.-1748 G＞A位点与305 d产奶量的相关性达到显著水平（P＜0.05）；g.13942T＞C位点与体细胞评分显著相关，CC基因型个体体细胞评分显著高于TT和 TC个体（P＜0.05）；g.14037A＞G位点AA基因型个体305 d产奶量显著高于AG个体（P＜0.05），AG基因型个体乳蛋白率显著高于GG个体（P＜0.05）。共构建出8种单倍型，发现了19种单倍型组合；H4H4单倍型组合个体的乳脂率和乳蛋白率均最高；H2H5单倍型组合个体305 d产奶量最高；H3H4单倍型组合个体体细胞评分最低。【结论】Tf基因不同基因型和单倍型组合与中国荷斯坦牛产奶量、乳蛋白率和体细胞评分存在显著相关性，但与乳脂率不相关。

SNPs Detection in Chinese Holstein Cattle Transferrin Gene and Its Associations with Milk Performance

【Objective】The polymorphisms of transferrin gene and their correlation to milk performance and healthy traits in Chinese Holstein cattle were investigated, which may help to breed high milk yield and healthy cows.【Method】DNA sequencing, PCR-RFLP and CRS-PCR were applied to analyze the polymorphisms of transferrin gene in 576 Chinese Holstein cattle and its associations with production performance were investigated by SAS software.【Result】Three novel SNPs (g.-1748G＞A, g.13942T＞C and g.14037A＞G) in the 5′flanking region, exon 8 and intron 8 of Tf gene were found, respectively. The locus g.-1748G＞A was significantly associated with 305 d milk yield (P＜0.05). The locus g.13942T＞C was significantly associated with somatic cell score. The cows with genotype CC was significantly higher than TT and TC genotype (P＜0.05). At locus g.14037A＞G , the cows with genotype AA showed higher 305 d milk yield than those with genotypes AG (P＜0.05), with genotype AG showed higher protein rate than those with genotypes GG (P＜0.05). Eight haplotype and 19 haplotype combinations were found in 576 Chinese Holstein cattle. The cows with haplotype combinations H4H4 had the highest milk fat and milk protein percentage. The cows with haplotype combinations H2H5 had the highest 305 d milk yield and the cows with haplotype combinations H3H4 had the lowest somatic cell score.【Conclusion】The correlation was detected between different genotypes and haplotype combinations of Tf gene and milk yield, protein rate and somatic cell score, but there was no correlation between the polymorphisms and milk fat rate.