秦川肉牛FGF2基因多态性与其生长和肉质性状的关联分析

Association of FGF2 gene polymorphism with growth and meat quality traits of Qinchuan beef cattle

【目的】研究秦川肉牛FGF2基因的多态性及其与肉牛生长和肉质性状的关联性。【方法】选取18~24月龄的健康秦川肉牛384头,测定其生长和肉质性状指标,采集血样,采用DNA技术检测FGF2基因全部外显子中的单核苷酸突变位点,对突变位点进行基因型分型,研究其单核苷酸基因多态性(SNP),并以一般线性模型(GLM)分析该SNP位点与秦川肉牛生长和肉质性状的关联性。【结果】在第1、2外显子上未发现突变位点,在第3外显子上存在4个SNP突变位点:SV1(g.A54740>T),SV2(g.A54758>C),SV3(g.T56809>C)和SV4(g.C59443>T)。其中,SV1有AA、AT和TT 3种基因型,SV2有AA、AC和CC 3种基因型,SV3有TT、TC和CC 3种基因型,SV4有CC、CT和TT 3种基因型。相比其野生基因型,SV1位点突变会降低体斜长、体高、腰高、胸深、胸围、腰角宽、尻长和体质量性状(P<0.05);SV2、SV3和SV4位点突变会改善这些性状(P<0.05);SV1位点突变会降低坐骨端宽性状(P<0.05),但SV3和SV4位点突变会改善坐骨端宽性状(P<0.05);SV4位点突变会改善背膘厚性状(P<0.05);SV2和SV4位点突变会改善眼肌面积性状(P<0.05);SV1突变会改善肌间脂肪性状(P<0.05)。【结论】FGF2基因对秦川肉牛生长性状和肉质性状有一定影响,可作为秦川肉牛现代分子选育的候选参考基因。

[Objective] This study investigated the correlation between gene FGF2 polymorphism and growth traits of Qinchuan beef cattle. [Method] A total of 384 healthy Qinchuan beef cattle with the age of 18 to 24 months were selected. The growth and meat quality traits were determined, and blood samples were collected for testing all mutational sites of mononucleotide in all exon of FGF2 gene with DNA testing technique. Then,the gene single nucleotide polymorphism （SNP） was studied,and the correlation between SNPs and growth and meat quality traits was determined with general linear model （GLM）. [Result] There was no SNP in the first and second exons,and there were four SNPs in the third exon including SV1 （g. A54740〉T） ,SV2（g. A54758〉C） ,SV3（g. T56809〉C） ,and SV4（g. C59443〉T）. SV1 had three geno- types,AA,AT and TT,SV2 had AA,AC and CC,SV3 had TT,TC and CC,and SV4 had CC,CT and TT, respectively. The averages of growth traits in SV1 mutant group including body length,withers height,hip height, chest depth, heart girth, hip width, rump length and body height were lower than those in wild type group（P〈0. 05）. On the contrary, these growth traits in SV2, SV3 and SV4 groups were greater than those in wild type group,indicating that the mutations at SV2,SV3 and SV4 improved growth traits （P〈 0.05）. Similarly,the mutation at SV1 decreased the pin bone width trait,while the mutations at SV3 and SV4 loci increased it （P〈0.05）. The mutation at SV4 also improved the back fat thickness trait （P〈 0.05） ,the mutations at SV2 and SV4 increased the eye muscle area trait （P〈0.05） ,while the mutation at SV1 enhanced the intramuscular fat trait （P〈0.05）. [Conclusion] FGF2 had influences on growth traits of Qinchuan beef cattle,and can be taken as reference for modern molecular breeding.