Abstract:Melanoeortin receptor-4 gene (MC4R) belongs to the super family of G protein-coupled receptors that is implicated in the control of feeding behavior and energy homeostasis in mammals. This study aimed to explore the association of single nucleotide polymorphism (SNP) of MC4R gene with Tibetan sheep (Ovis aries) growth traits, so as to search for molecular markers related with growth traits, DNA sequencing method was applied to detect and genotype polymorphisms within MC4R gene in Tibetan sheep populations, and analyzed the associations of polymorphisms and combined genotypes with growth traits of Tibetan sheep. Results showed that 4 SNPs in MC4R gene were detected, including g.1803G>A in exon 1, g.1261T>C in intron 2 and two mutants (g.1803G>A and g.1918C>T) in 3'-untranslated region (3'UTR). Association analysis in 555 Tibetan sheep population indicated that, at g.880G>A locus, individuals with genotype AA had larger higher body weight, body height, body length and chest circumference compared with the genotype GG (P<0.01 or P<0.05). At g.1261T>C locus, the body weight of animals with TC genotype was significantly higher (P<0.05) than that of animals with TT genotype. Moreover, the g.1803G>A locus was significantly affected body weight (P<0.01), and GG was the preferable genotype. The optical combined genotype of MC4R was diplotype H13H7 (GTGC-ATAC), which was more effective on growth traits than other combined genotypes (P<0.05). These results suggested that the single nucleotide polymorphisms and combined genotypes of MC4R gene affected the growth traits of Tibetan sheep, and they could be used as candidate genes for breeding Tibetan sheep with better growth traits.
[1] Xin G S, Long R J, Guo X S, et al. 2011. Blood mineral status of grazing Tibetan sheep in the Northeast of the Qinghai–Tibetan Plateau[J]. Livestock Science, 136(2–3): 102-107.[2] Zhou J W, Mi J D, Titgemeyer E C, et al. 2015. A comparison of nitrogen utilization and urea metabolism between Tibetan and fine-wool sheep[J]. Journal of Animal Science, 93(6): 3006-3017.[3] 向泽宇, 王长庭. 2011. 青藏高原藏羊遗传资源的现状、存在问题及对策[J]. 中国畜牧兽医文摘, 27(2): 1-4. ( Xiang Z Y, Wang C T. The qinghai-tibet plateau Tibetan sheep genetic resources present situation, problems and countermeasures[J]. ZHONGGUO XUMU SHOUYI WENZHAI, 27(2): 1-4. )[4] Wang C, Mao D, Cao S, et al. 2014. CRS-PCR polymorphism of MC4R gene in six sheep herds and its relationship to growth traits in Hu sheep and East Friesian × Hu crossbred sheep[J]. Journal of Nanjing Agricultural University, 37(1): 121-126.[5] Yeo G S, Farooqi I S, Challis B G, et al. 2000. The role of melanocortin signalling in the control of body weight: evidence from human and murine genetic models[J]. Qjm Monthly Journal of the Association of Physicians, 93(1): 7-14.[6] Tao Y X. 2010. The melanocortin-4 receptor: physiology, pharmacology, and pathophysiology[J]. Endocrine Reviews, 31(4): 506-543.[7] Mul J D, Van B R, Bergen D J, et al. 2012. Melanocortin Receptor 4 Deficiency Affects Body Weight Regulation, Grooming Behavior, and Substrate Preference in the Rat[J]. Obesity, 20(3): 612–621.[8] Huszar D, Lynch C A, Fairchildhuntress V, et al. 1997. Targeted disruption of the melanocortin-4 receptor results in obesity in mice[J]. Cell, 88(1): 131–141.[9] Obici S, Feng Z, Tan J, et al. 2001. Central melanocortin receptors regulate insulin action[J]. Journal of Clinical Investigation, 108(7): 1079-1085.[10] Wang G, Zhang S, Wei S, et al. 2014. Novel polymorphisms of SIX4 gene and their association with body measurement traits in Qinchuan cattle[J]. Gene, 539(1): 107-110.[11] 孙俊枝, 解雅英, 褚海辰,等. 2016.慢性坐骨神经损伤大鼠中脑导水管周围灰质MC4R的表达及HS014对热痛觉过敏的影响[J]. 现代中西医结合杂志, 25(35): 3892-3895. (Sun J Z, Jie Y Y, Chu S J, et al. 2016. Change of MC4R expression in periaqueductal gray in rats with CCI and effect of selective antagonist HS014 on their thermal hyperalgesia[J]. Modern Journal of Integrated Chinese Traditional and Western Medicine, 25(35): 3892-3895. )[12] 李徽徽, 仇大鹏, 高琴,等. 2016.选择性激动黑皮质素4型受体(MC4R)通过HMGB1/TLR4/NF-κB信号途径对抗大鼠脓毒症致急性肝损伤[J]. 细胞与分子免疫学杂志, 32(8): 1055-1059. (Li H H, Qiu D P, Gao Q, et al. 2016. Selectively activating melanocortin 4 receptor acts against rat sepsis-induced acute liver injury via HMGB1 / TLR4 / NF-κB signaling pathway[J]. Chinese Journal of Cellular and Molecular Immunology, 32(8): 1055-1059. )[13] Hong J, Kim D, Cho K, et al. 2015. Effects of genetic variants for the swine FABP3, HMGA1, MC4R, IGF2, and FABP4 genes on fatty acid composition[J]. Meat Science, 110: 46-51.[14] 李星润, 兰国湘, 王孝义,等. 2016. 猪MC4R基因Asp298Asn位点多态性及其与生长性状的关联[J]. 畜牧与兽医, 48(2): 23-27. ( Li X R, Lan G X, Wang X Y, et al. 2016. Polymorphism of Asp298Asn site in the porcine MC4R gene and its association with growth traits[J]. Animal Husbandry and Veterinary Medicine,48(2): 23-27. )[15] Wyatt L A, Mapp P I, Wilson D, et al. 2016. Gene expression patterns in the synovium and their association with symptomatic knee osteoarthritis[J]. Osteoarthritis and Cartilage, 24: S28-S29.[16] Kathrani A, House A, Werling D, et al. 2010. Overdominant single nucleotide polymorphisms in the nucleotide oligomerisation domain two (nod2) gene are significantly associated with canine inflammatory bowel disease[J]. Journal of Veterinary Internal Medicine, 24(3): 725-725.[17] 张俊, 钱勇, 钟声,等. 2014. 波尔山羊MC4R胞内3环基因片段单核苷酸多态性对体重的影响[J]. 江苏农业科学, 42(3):13-15.(Zhang J, Qian Y, Zhong S, et al. 2014. Polymorphisms of hird intracellular loop of MC4R gene in Boer goat and its effects on body weight traits[J]. Jiangsu Arricultural Sciences, 42(3): 13-15. )[18] 张子军, 程箫, 刘洪瑜,等. 2012. 山羊MC4R基因cDNA的克隆和序列分析及组织表达研究[J]. 西北农林科技大学学报自然科学版, 40 (12): 20-26. (Zhang Z J, Cheng X, Liu H Y, et al. 2012. cDNA cloning, sequence analysis and tissue expression of goat MC4R gene[J]. Journal of Northwest A&F University (Nat. SCi. ED), 40(12): 20-26. )[19] Zhang Y R, Gui L S, Li Y K, et al. 2015. Molecular Characterization of Bovine SMO Gene and Effects of Its Genetic Variations on Body Size Traits in Qinchuan Cattle (Bos taurus)[J]. International Journal of Molecular Sciences, 16(8): 16966-16980.[20] 桂林生, 昝林森, 王洪宝, 等. 2015. SIRT1和SIRT2基因多态性及合并基因型与秦川牛肉用性状的关联分析[J]. 畜牧兽医学报, 46(10): 1741-1749. (Gui L S, Zan L S, Wang H B, et al. 2015. Effects of Single and Combined Genotypes of SIRT1 and SIRT2 Genes on Meat Quality Traits in Qinchuan Cattle[J]. Acta Veterinaria et Zootechnica Sinica, 46(10): 1741-1749. )[21] Hoggard N, HUNTER L, DUNCAN J S, et al. 2004. Regulation of adipose tissue leptin secretion by alpha-melanocyte-stimulating hormone and agouti-related protein: further evidence of an interaction between leptin and the melanocortin signalling system[J]. Journal of Molecular Endocrinology, 2004, 32(1): 145-153.[22] Almundarij T I, Smyers M E, Spriggs A, et al. 2016. Physical Activity, Energy Expenditure, and Defense of Body Weight in Melanocortin 4 Receptor-Deficient Male Rats[J]. Scientific Reports, 6:37435.[23] 李庆岗, 陶立, 季香, 等. 2009. MC4R基因在淮猪中的多态性及其与生长性状和背膘厚的相关性[J]. 安徽农业科学, 37(3): 999-1000. (Li Q G, Tao L, Ji X, et al. 2009. Studies on Polymorphisms of the MC4R Gene in New-strain Huai Pig Breed and Its Effects on Growth and Back-fat Traits abstract[J]. Journal of Anhui Agricultral, 37(3): 999-1000. )[24] 王春玲, 茆达干, 曹少先,等. 2014. 6个绵羊群体MC4R基因CRS.PCR多态性及其与湖羊、东湖杂交羊生长性状的关联分析[J]. 南京农业大学学报, 37(1): 121-126. (Wang C L, Mao D, Cao S X, et al. 2014. CRS-PCR polymorphism of MC4R gene in six sheep herds and its relationship to growth traits in Hu sheep and East Friesian × Hu crossbred sheep[J]. Journal of Nanjing Agricultural University, 37(1): 121-126. )[25] 刘洪瑜, 王恒, 任春环, 等. 2012. 牛MC4R基因多态性与体尺性状的相关分析[J]. 中国兽医学报, 32(9): 1309-1311. (Liu H Y, Wang H, Ren C H, et al. 2012. Polymorphism of MC4R gene and correlation analysis with body size traits in cattle[J]. Chinese Journal of Veterinary Science, 32(9): 1309-1311. )[26] Li M, Sun X, Hua L, et al. 2013. SIRT1 gene polymorphisms are associated with growth traits in Nanyang cattle[J]. Molecular and Cellular Probes, 27(5): 215-220. [27] Cao F, Zhang H, Feng J, et al. 2013. Association study of three microsatellite polymorphisms located in introns 1, 8, and 9 of DISC1 with schizophrenia in the Chinese Han population[J]. Genetic testing and molecular biomarkers, 17(5): 407-411.[28] Yie S, Li L, Xiao R, et al. 2008. A single base-pair mutation in the 3'-untranslated region of HLA-G mRNA is associated with pre-eclampsia[J]. Molecular Human Reproduction, 14(11): 649-653.[29] 徐晨希, 王梦琦, 朱小瑞,等. 2016. 中国荷斯坦牛FADS2基因3'端SNP突变对乳中脂肪酸组成的影响[J]. 中国农业科学, 49(11): 2194-2202. (Xu C X, Wang M Q, Zhu X R, et al. 2016. Effects of SNP in the 3’Untranslated Regions of FADS2 on the Composition of Fatty Acids in Milk of Chinese Holstein[J]. Scientia Agricultura Sinica, 49(11): 2194-2202. )[30] Ren G, Chen H, Zhang L Z, et al. 2010. A coding SNP of LHX4 gene is associated with body weight and body length in bovine[J]. Molecular Biology Reports, 37(1): 417-422.