ObjectiveIn order to provide scientific data for understanding the adaptive mechanism of Schizopygopsis pylzovi to seasonal cold environment at Qinghai-Tibetan Plateau, the obese gene (ob) of Schizopygopsis pylzovi was cloned and its encoding protein leptin was analyzed. Then the expression pattern of the ob mRNA in tissues and the relative expression level of the ob mRNA in hepatopancreas and white muscle of Schizopygopsis pylzovi from habitats of different temperatures were assessed. Methods The full-length cDNA of ob gene was cloned by RT-PCT, 5′-RACE and 3′-RACE methods. The expression pattern and relative expression level were determined by RT-PCR and real-time PCR. ResultsThe full-length cDNA of ob gene was 1 337 bp, including a 513 bp complete ORF encoding a 170 amino acid peptide. The ob gene was expressed in the nine examined organs, including heart, kidney, fat, intestine, spermary, hepatopancreas, gill, brain and muscle, while strongly expressed in heart and weakly expressed in muscle. The ob gene expression in the hepatopancreas and white muscle of Schizopygopsis pylzovi was suppressed by low temperature. ConclusionsThe tissue expression pattern of ob gene in Schizopygopsis pylzovi may be related to energy metabolism and biological functions in specific tissues. The encoding protein leptin plays an important role in the regulation of energy metabolism of Schizopygopsis pylzovi, as well as its adaptation to the seasonal cold environment at Qinghai-Tibetan Plateau.