Laboratory of Small Ruminant Genetics, Breeding and Reproduction, Huazhong Agricultural University, Wuhan 430070, China.
Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of the Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China.
Int J Mol Sci. 2019 Jan 9;20(2):240. doi: 10.3390/ijms20020240.
The () gene is expressed in the appetite-regulating areas of the brain and is engaged in the leptin signaling pathway. Although previous studies have identified variants in the coding region of the sheep gene showing significant associations with birth weight, weaning weight, and backfat thickness, no such associations have been reported for the promoter region. Besides, the essential promoter region of the sheep MC4R has not been delineated. In this study, to better understand the transcriptional regulation of and to elucidate the association between regulatory variants and haplotypes with body measurement traits in sheep, we cloned and characterized the promoter. We found that the minimal promoter of the gene is located within the region -1207/-880 bp upstream of the first exon. Real-time quantitative PCR (RT-qPCR) data revealed the mRNA expression of the gene had a significant difference between sex and age. In the association analysis, eight single nucleotide polymorphisms (SNPs) had a significant association with one or more traits ( < 0.05); of these, two SNPs were novel. Notably, individuals with haplotype H1H2 (CT-GA-GT-GA-GT-GA-GA-CG) were heavier in body weight than other haplotypes. Altogether, variations in the gene promoter, most notably haplotype H1H2, may greatly benefit marker-assisted selection in sheep.
（）基因在调节食欲的大脑区域表达，并参与瘦素信号通路。尽管先前的研究已经确定了绵羊基因编码区域的变异与出生体重、断奶体重和背膘厚显著相关，但在启动子区域没有发现这种关联。此外，绵羊 MC4R 的必需启动子区域尚未确定。在这项研究中，为了更好地理解和阐明与身体测量性状相关的调控变异和单倍型之间的关系，我们克隆并表征了的启动子。我们发现该基因的最小启动子位于外显子 1 上游的-1207/-880bp 区域内。实时定量 PCR（RT-qPCR）数据显示基因的 mRNA 表达在性别和年龄之间存在显著差异。在关联分析中，有 8 个单核苷酸多态性（SNPs）与一个或多个性状显著相关（<0.05）；其中 2 个 SNP 是新的。值得注意的是，与其他单倍型相比，具有单倍型 H1H2（CT-GA-GT-GA-GT-GA-GA-CG）的个体体重更重。总之，基因启动子的变异，尤其是单倍型 H1H2，可能极大地有益于绵羊的标记辅助选择。
