MC4R基因多态性与鸡生长和体组成性状的相关研究

黑素皮质素受体4(melanocortin4receptor,MC4R)是G蛋白偶联受体(GProteincoupledreceptors,GPCRs)超家族的一个成员,在人和鼠的体重、能量稳态和采食量的调控中具有重要作用。实验以东北农业大学建立的高低脂双向选择肉鸡品系为研究材料,采用PCR-SSCP和测序方法检测MC4R基因编码区的SNPs,结果在编码区发现1个G315T的突变。最小二乘分析表明,该位点基因型在高低脂系6世代中与7周龄体重、屠体重呈显著相关(P<0.05),多重比较显示,AA型个体的7周龄体重、屠体重显著高于AB型的个体(P<0.05);在高低脂系8世代中基因型与1、5、7周龄体重、屠体重、胸肌重、胸肌率显著相关(P<0.05),多重比较结果表明,AA型个体的5、7周龄体重、屠体重、胸肌重显著高于AB型和BB型个体(P<0.05)。由结果可初步推测MC4R基因可能是影响鸡早期生长和肌肉性状的主效基因或与主效基因相连锁。

Study on the correlation between SNP of MC4R and body weight and fat traits in chicken

Melanocortin-4 receptor(MC4R) is a member of the superfamily of G protein coupled receptors(GPCRs),and can affect body weight,energy homeostasis and food intake in human and mouse.The objectives of the present study were to identify polymorphisms of MC4R gene and develop PCR-SSCP and to use DNA sequencing methods to detect those DNA polymorphisms in population of NEAU broiler lines for divergent selection on abdominal fat.A G/T mutation at base position 315 was found in coding sequence region of chicken MC4R gene.The least square analysis showed that the genotype of mutation had significant association with body weight,carcass weight at 7 weeks in population of sixth generation(P < 0.05).Results of multiple comparison evealed that AA birds had significant higher(P < 0.05) body weight,carcass weight than AB birds.There was a significant association between the genotype and body weight at 1,5,7 weeks,and carcass weight,breast muscle weight and percentage of breast muscle at 7 weeks,and results of multiple comparition revealed that AA birds had significant higher(P < 0.05) body weight at 5 and 7 weeks,and carcass weight and breast muscle weight than AB and BB birds at 7 weeks.We can putatively draw the conclusion that MC4R gene was the major gene affecting the body weight,muscle traits in chicken,or linked to the certain major gene.