东佛里生羊MSTN基因多态性及其与生长性状的关联分析

试验旨在研究肌肉生长抑制素(myostatin,MSTN)基因多态性及其对东佛里生羊生长性状的影响。从324只东佛里生羊全血中提取DNA,对MSTN基因外显子序列和非翻译区(untranslated region,UTR)序列进行PCR扩增,采用一代测序技术鉴定单核苷酸多态性(single nucleotide polymorphism,SNP)位点,分析不同位点的遗传多态性,并将不同基因型与东佛里生羊的生长性状进行关联分析。结果显示,在东佛里生羊MSTN基因外显子中未检测到突变;在3'-UTR区的272 bp处存在G→A单碱基突变,该位点只检测到AG和AA基因型,且AA基因型频率高于AG基因型;在5'-UTR区的176 bp处存在C→A突变,该位点只检测到CC和AC基因型,且CC基因型频率高于AC基因型。遗传多样性参数分析结果表明,东佛里生羊群体MSTN基因3'-UTR-272和5'-UTR-176位点的纯合度分别为0.827和0.887,杂合度分别为0.173和0.113,2个位点的多态性均较低(PIC<0.25),其群体基因型分布均符合哈代-温伯格平衡(P>0.05)。关联分析发现,3'-UTR-272位点AG基因型体斜长显著高于AA基因型(P<0.05),5'-UTR-176位点CC基因型胸围显著高于AC基因型(P<0.05),其余指标均无显著差异(P>0.05)。综上,东佛里生羊MSTN基因3'-UTR和5'-UTR突变位点可作为其目标性状选育的分子标记。

Polymorphism of MSTN Gene and Its Association with Growth Traits in East Friensian Sheep

This study was aimed to explore the polymorphism of myostatin (MSTN) gene and its effect on the growth traits in East Friensian sheep.DNA was extracted from a total of 324 East Friensian sheep, PCR amplification was performed on the exon sequence and UTR of MSTN gene.SNP were identified by the first-generation sequencing technology and its genetic diversity parameters were analyzed.At the same time, the association analysis between genotypes and growth traits at different loci was carried out.The results showed that no mutation was detected in exon of MSTN gene in East Friensian sheep, but there was a G→A single-base mutation at 272 bp in 3'-UTR region, which contained AG and AA genotypes.The frequency of AA genotype was higher than that of AG genotype.A mutation of C→A was detected at 176 bp of 5'-UTR, which contained CC and AC genotypes, and the frequency of CC genotype was higher than that of AC genotype.The results of genetic diversity parameter analysis showed that the homozygosity of 3'-UTR-272 and 5'-UTR-176 of MSTN gene in East Friensian sheep were 0.827 and 0.887, and the heterozygosity were 0.173 and 0.113, respectively.The polymorphisms of the two loci were low (PIC<0.25), and the genotype distribution accorded with Hardy-Weinberg equilibrium (P>0.05).Through association analysis, the body oblique length of AG genotype was significantly higher than that of AA genotype at 3'-UTR-272 (P<0.05), the chest circumference of CC genotype was significantly higher than AC genotype at 5'-UTR-176 (P<0.05), and there was no significant difference in other traits (P>0.05).This results suggested that the 3'-UTR and 5'-UTR mutation of MSTN gene in East Friensian sheep could be considered as molecular markers for the selection of target traits.