Abstract：G protein-coupled receptor 43(GPR43) is the member of G protein-coupled receptors(GPCRs) family and has a potential role of regulating lipid metabolism. The aim of this study was to clone GPR43 and analyze its mRNA expression level in different tissues and lactation periods of diary goats(Capra hircus). Based on the published nucleotide sequence of bovine(Bos taurus) GPR43 gene(NM_001163784) in GenBank, a pair of specificity primers was designed. Coding sequence(CDS) of GPR43 was amplified (GenBank accession number: HM623658) by RT-PCR. The results showed that the CDS length of GPR43 gene was 987 bp, coding 329 amino acids. The homology analysis of dairy goat GPR43 gene indicated that the nucleotides and amino acids had high similarity with bovine, human(Homo sapiens) and mice (Mus musculus) and reached up to more than 90% with bovine. The protein structure analysis showed that GPR43 protein had 7 transmembrane helices and the C-terminal was high hydrophobic but the N-terminal showed high hydrophilism. Real-time quantitative PCR was used to detect the expression of GPR43 gene in different tissues. The results suggested that GPR43 mRNA expressed in all 10 tissues examined. GPR43 mRNA expressed abundantly in spleen, followed by the small intestine, liver, adipose tissues but the lowest in lung, muscle and kidney, and the relative low expression was also detected in mammary gland tissue. Two lactation stages expression analysis showed that expression of GPR43 gene was significantly higher in the lactation stage than that of dry stage (P＜0.05). Taken together, these results demonstrated that GPR43 had a different range of tissue-speci?c expression, and might play an important role during lactation stages in dairy goat. In conclusion, this work serves as the basis for further study on GPR43 in the dairy goat mammary gland.
