Molecular Cloning Of Mel-1c Gene And The Concentration Of Melatonin In Goose

The hormone melatonin is secreted primarily from the pineal gland. It appears to be involved in the regulation of various neural and endocrine processes that are cued by the daily change in photoperiod. Melatonin displayed higher levels occurring during the dark period of a circadian cycle. The concentration of melatonin and its receptor shows seasonal variation, with higher levels in summer and autumn. In mammals, melatonin also influences the reproductive function via activation of receptor sites within the hypothalamic-pituitary-gonadal axis. In birds, melatonin regulates circadian rhythm, hibernation, feeding pattern, thermoregulation, and neuroendocrine function. Melatonin receptors are expressed in neural and peripheral tissues and mediate melatonin actions on the and circannual rhythms. Three types of melatonin receptor have been cloned. The Mel-la、Mel-lb receptor subtypes are present in humans and other mammals, while an additional melatonin receptor subtype Mel-lc has been identified in the amphibian, fish and birds, not in the mammals. The aim of this paper is to clone the full-length coding sequence of Mel-lc in the goose, Identification of characteristics single nucleotide polymorphisms (SNPs) existing in coding region of Mel-lc in goose. Detecting the content of melatonin and analyze its relationship with the breeds and seasonal changes, providing a basis of improving reproductive performance through regulating secretion of melatonin.The cDNA of Mel-lc full coding sequence in goose was cloned by using SMARTer RACE strategy. The total RNA extracted from the brain of goose was transcript into cDNA. Primers were designed according to the chicken Mel-lc conserved domain sequence to amplify goose Mel-lc. NCBI blast result indicated that Mel-lc share91%nucleotides identity and97%amino acids identity with Gallus gallus Mel-lc (U31821).Genomic DNA was extracted from blood cells of goose, the coding regions were amplified by PCR, After sequenced, the information wan aligned and summarized. Four SNP sites in Mel-lc were identified, in which there are three sites in coding region, including G486A、G501A and T699A. but did not cause amino substitute. And G1116A and G1119A were in3’uncoding region.ELISA and RIA was applied to detect the concentration of melatonin in serum in different breeds of goose and in different months. The result shows that the content of melatonin in the Wanxi White Goose is higher than the White Roman Goose, The average concentration of melatonin in August is higher than in June. Conclusion:the concentration of melatonin in goose correlated significantly with breeds and seasonal change.