Cloning, expression and chromosome localization of porcine adiponectin and adiponectin receptors genes

Adiponectin is a cytokine secreted specifically by adipocytes that has been proposed to enhance insulin sensitivity and prevent atherosclerosis. Adiponectin receptors (adipoR1 and adipoR2) are recently found in mice which act as receptors for globular and full-length adiponectin to mediate the fatty-acid oxidation and glucose uptake in muscle and liver. The primary goal of this study was to examine chromosome localization of porcine adiponectin and adiponectin receptors and the gene expression pattern in various tissues of pigs of the three genes. Radiation hybrid mapping demonstrated that porcine adiponectin, adipoR1 and adipoR2 were located to chromosome13q36-41, 10p11 and 5q25, in the regions that were syntenic to the homologs of human genes, respectively. Semi-quantitative RT-PCR showed that porcine adiponectin mRNA was specifically expressed in adipose tissue and porcine adipoR1 and adipoR2 mRNA were ubiquitously expressed in many tissues except brain. Comparison to adipoR2 mRNA which was highly expressed in liver, heart, kidney, adipose tissues and lung, adipoR1 mRNA was expressed at relatively high levels in porcine muscle, leukocytes and epididymis. Our data provide basic molecular information useful for the further investigation on the function of the three genes.