Ghrelin is a novel growth hormone (GH)-releasing peptide,which has been identified as an endogenous ligand for GH-secretagogue receptor.The sequence of ghrelin has been determined in many species from fish to mammals.In this study,to reveal the production and characteristic of ghrelin in the reindeer (Rangifer tarandus),the full-length cDNA encoding ghrelin were cloned from reindeer stomach using reverse transcription PCR(RT-PCR) and rapid amplification of complementary deoxyribonucleic acid ends (RACE).Results of cDNA cloning and sequence analysis revealed that the full-length of reindeer ghrelin cDNA was composed of 604 bases that included a 5′-untranslated region (57 bp),an open reading frame (ORF) (405 bp) encoding a prepro-ghrelin of 134 amino acids,and a 3′-untranslated region (142 bp).The predicted prepro-ghrelin of 134 amino acids included N-terminal signal peptide of 41 amino acids that was longer than any other animals ghrelin,the predicted mature ghrelin peptide of 27 amino acids which showed high homology to goat (100％),sheep (100％) and cattle (96.3％) mature ghrelin peptide,and C-terminal peptide of 66 amino acids.Thus,the present study indicates a structural divergence of peptide length in reindeer ghrelin.In conclusion,we have identified a noval ghrelin from reindeer,and found that it is highly conserved with other ruminants ghrelin sequences.