Abstract: The mRNA differential display PCR is widely used to investigate the differential gene expression in response to different environments in plants,animals and microorganisms.In this study,the technique was used to analyze the differential gene expression in Mortierella isabellina strain M6-22 which was cultured at 15 ℃ and 30 ℃,respectively.The results showed that 7 fragments whose mRNA levels were increased by 2 times or more at 15 ℃ were obtained from 21 candidate fragments after verification by real-time quantitative PCR.They showed high amino acid sequence similarity to glucose-6-phosphate isomerase,sugar-nucleotide transporter,ras1 guanine nucleotide exchange factor,NAD dependent malate dehydrogenase,Δ12-fatty acid desaturase and CLK4-associating serine/arginine rich protein,being potentially involved in the life processes of glycolysis,protein modification,signal transduction,fatty acid biosynthesis and mRNA processing,et al.These results indicate that the adaptation of M. isabellina M6-22 to low temperature is a coordinate regulation of multiple pathways.