Abstract：Peroxisome proliferator activated receptor γ(PPARγ) plays an important role in the metabolism process of fat and glucose. In order to explore the function of PPARγ gene during lacation in dairy goat(Capra hircus), the experiments were designed to clone the whole cDNA of PPARγ gene by RT-PCR and RACE from Xinong Saanen dairy goat mammary gland, to analyze its expression in ten tissues and mammary tissue in different lactation periods and to detect the expressions of fatty acid metabolism related genes in mammary epithelial cell treated with rosiglitazone(ROSI) by qRT-PCR. The whole cDNA sequence of PPARγ gene was isolated from the dairy goat (GenBank accession NO.HQ589347). Homology alignments revealed that PPARγ gene was conservative among the mammalian. Structure prediction showed that there were two zinc finger structures and a ligand binding domain in the dairy goat PPARγ protein. Tissue spectral analysis showed that PPARγ gene had the most abundant expression in adipose tissue, followed by the rumen and the minimal expression was detected in muscle. Expression analysis in the two different lactation periods of mammary tissue revealed that the PPARγ mRNA level during lactation peak was about twice than that of dry period. After treatment with rosiglitazone， a specific agonist， in goat mammary epithelial cells, some fatty acid related genes such as LPL(lipoprotein lipase ), FABP3(fatty acid binding protein), ADRP(adipose differentiation related protein) and TIP47(tail-interacting protein 47) were up-regulated significantly. These results indicate that the PPARγ gene may play an important role in fatty acid metabolism during the dairy goat lactation process, and provide the basic data for further research in regulating milk fat, improving the quality of milk and developing mammary gland bioreactor in the individual level.
