Cloning and starvation response of mc5r gene in Spinibarbus hollandi

In this study, melanocortin receptor-5 (mc5r) gene of Spinibarbus hollandi was cloned by homology cloning and genome walking method. Bioinformatics methods were used to analyze the gene sequence and deduced amino acid sequence of mc5r. The tissue distribution, diurnal change and starvation response of mRNA expression were detected by real-time PCR. The full length of mc5r gene was 1 947 bp with one exon of 987 bp encoding 329 amino acids. According to multiple sequences alignment and phylogeny evolution analysis, the homology of S. hollandi mc5r amino acid sequence with Cyprinus carpio and Sinocyclocheilus rhinocerous reached 98%. S. hollandi mc5r had significant expression in brain, followed by diencephalon and heart, relatively less in mesencephalon and cerebellum, and weak in kidneys, stomach, muscles, spleen, intestines, gonadal, liver, medulla oblongata and eye. The diurnal periodicity expression of mc5r mRNA changed with day and night regularly. In the starvation refeeding experiment, the expression of refeeding fish increased significantly after starvation, but then decreased. It is indicated that mc5r may have some effects on food intake regulation.