牛SCD1基因C878T位点遗传多态性与中国西门塔尔牛部分脂肪相关性状的效应分析

Genetic Variation at C878T in Bovine SCD1 Gene and Its Association with Some Fat Traits in Chinese Simmetal Cattle

为探索8个中国牛群SCD1基因多态性与屠宰和肉质性状的相关性,选取中国西门塔尔牛、雷琼牛、云南高峰牛、BMY牛、闽南黄牛、鲁西黄牛、渤海黑牛和中国南方荷斯坦牛等8个群体共682头个体为研究对象,采用PCR-SSCP法分析SCD1基因遗传多态性。结果表明,在878bp处发现1个碱基C→T的突变(C878T),导致蛋白质肽链中丙氨酸(alanine)突变为缬氨酸(valine)。C878T位点在所研究群体中表现为CC、CT和TT3种基因型,其中,中国西门塔尔牛中TT基因型频率较高(0.114),鲁西黄牛和渤海黑牛中较低(0.050/0.063),4个热带群体中未发现TT基因型。采用GLM对SCD1基因C878T位点与132头中国西门塔尔屠宰牛的部分脂肪相关性状进行关联分析。结果,CC基因型个体肌间脂肪含量和肠系膜油质量显著高于TT型个体(P<0.05),背膘厚极显著低于TT型个体(P<0.01),其他性状间差异不显著(P>0.05)。结果表明,SCD1基因C878T位点突变对中国西门塔尔牛脂肪相关性状有较大的遗传效应,可用于其部分屠宰与肉质性状的分子标记辅助选择。

This experiment was conducted to study the effect of SCD1 gene.To explore the effect of genetic variance in SCD1 gene on carcass and meat traits,682 cattle were selected randomly,including Chinese Simmetal cattle（Simme）,Leiqiong cattle（LQ）,Yunnan Gaofeng cattle（GF）,BMY cattle（BMY）,Minnan cattle（MN）,Luxi cattle（LX）,Bohai Black cattle（BH） and Holstein of South Chinese（Hols.）,the polymorphism of specific fragment of SCD1 gene was analyzed by PCR-SSCP technique.A nucleotide mutation had been found at site 878,leading to an amino acid change（Glycine to Valine） at site 293,it was C878T.Three genotypes（CC,CT and TT） had been found at this site,and the frequency of genotype TT was highest in Chinese Simmetal population with the value of 0.114,and lower in Luxi cattle,Bohai Black cattle and Holstein with the value of 0.050,0.063 and 0.040,respectively.But genotype TT had not been found in the four tropic populations including Leiqiong cattle,Yunnan Gaofeng cattle,BMY cattle and Minnan cattle.The individuals with CC genotype of SCD1 showed a higher content of IMF and Mesentery fat weight traits（P0.05）,but lower value of backfat thickness trait（P0.01）,compared to the individuals with TT genotype.There was no significant difference among different genotypes with other traits.The results indicate that the C878T mutation of SCD1 gene has a great genetic effect on carcass and meat traits and could be a useful genetic marker for Chinese beef breeding.