中文摘要：

旨在探讨CRTC3基因作为秦川牛生长性状候选基因的可能性,寻找与秦川牛生长相关的分子标记。本研究采用PCR-RFLP方法检测395头健康秦川牛CRTC3基因的多态性,分析其多态位点不同基因型及组合基因型与秦川牛生长性状的关联性。结果发现,CRTC3基因扩增序列区间存在2个SNPs位点（位于外显子区域的G66478C和位于内含子区域的C91297T）。关联性分析表明,在本试验所选取的395头秦川牛群体中,G66478C位点GC基因型个体在体斜长方面极显著高于CC型个体均值（P〈0.01）,且在胸深方面显著高于CC型个体均值（P〈0.05）。在C91297T位点,CT基因型个体均值在体斜长、腰高、尻长和胸深方面显著高于TT基因型个体均值（P〈0.01）。CRTC3基因的优势基因型组合CC-TT的个体在腰高、尻长上极显著高于CC-CT基因型组合的个体均值（P〈0.01）,且基因型组合CC-TT的个体在胸深、胸围显著高于CC-CT组合的个体均值（P〈0.05）。综上,可以尝试将CRTC3基因作为影响秦川牛生长性状的候选基因用于标记辅助选择,为秦川牛选育工作提供科学依据。

英文摘要：

The aim of this study was to investigate the possibility of CRTC3 gene as candidate gene for growth performance in Qinchuan cattle,and search the molecular markers related to Qinchuan cattle growth traits.PCR-RFLP method was applied to detect the polymorphisms of CRTC3 in 395healthy Qinchuan cattle,and the association of its polymorphisms and genotype combination with growth traits of Qinchuan cattle was also analyzed.The result showed that 2SNPs were identified,including G66478 Cin exon and C91297 Tin intron.At the G66478 Clocus,the cattle with genotype GC had greater body length and chest depth values than those with genotype CC（P〈0.01 and P〈0.05,respectively）.At the C91297 Tlocus,animals with genotype CT had greater body length,hip height,rump length and chest depth values than those with genotype TT（P〈 0.01）.Animals with CC-TT had significantly greater hip height and rump length values than those with CC-CT（P〈 0.01）,and chest depth and chest circumference values for CC-TT were greater than CCCT（P〈0.05）.Therefore,variations in the CRTC3 gene and the genotype combination CC-CT may beuseful as molecular markers for growth traits in Qinchuan cattle breeding.