Studies On The Cloning,Expression And Localization Of Reindeer Ghrelin Gene In Various Organs

Ghrelin, a peptide predominantly produced in the stomach exhibits numerous physiological functions, including stimulation of growth hormone release, food intake and gastric empting, and regulation of energy expenditure. This peptide exhibits also some protective and healing-promoting effects. But the function of Ghrelin in reindeer, a semi-wild animals, is not known. In the present study cloning was used to study the full-length of Ghrelin Genomic DNA, RT-PCR, RT-qPCR and Immunohistochemistry were used to examine the expression and localization of Ghrelin in the reindeer organs.The results showed that, the 4076 bp amplicon of Ghrelin genomic DNA consisting of 4 exons and 3 introns was cloned from Reindeer. RT-PCR and RT-qPCR results showed that, Ghrelin was expressed in hypothalamus, hypophysis, tongue, esophagus, rumen, reticulum, omasum, abomasum, duodenum, jejunum, ileum, colon, heart, lung, liver, spleen, kidney, bladder, ureter, testis, epididymis, ductus defrens, lymphatic node, thyroid gland, pancreas, adrenal gland, thymus, seminal vesicle gland, and skeletal muscle, where the expression in the abomasum was highest, and followed by pancreas, duodenal, testis and esophagus. The expression of Ghrelin in the hypothalamus, hypophysis and tongue was remarkably higher than the expression in other organs. Immunohistochemical results showed that, Ghrelin-positive cells in the esophagus and abomasum mainly distributed in the tunica mucosa, tunica submucosa and tunica muscularis and also detected in the tunica mucosa, tunica submucosa of rumen, reticulum, omasum. In the intestine, Ghrelin-positive cells were mainly localized in the tunica mucosa, tunica submucosa and tunica muscularis of duodenum, jejunum, ileum, colon.especially more cells were found in the epithelium of intestinal villi and the tunica submucosa. Ghrelin-positive cells also were observed in the liver, pancreas, lung, spleen, kidney, testis, anterior pituitary, thyroid gland.Ghrelin genomic DNA sequences was first successfully cloned to fill the Ghrelin gaps in wild ruminants and enrich the entire ruminants biology data. The expression and localization results indicate that Ghrelin have a wide range of physiological effects. This study results will have important significance for feeding reindeer artificially.