Study On The Differential Gene Expression Of Mortierella IsabellinaM6-22 At Low Temperature By MRNA Differential Display Technique

Mortierella is a genus of filamentous fungi with important economic value in the order Mucorales,the species in this genus produce a series of polyunsaturated fatty acids,and some species including Mortierella isabellina,have been used for the production of these polyunsaturated fatty acids by microbiological fermentation.Our previous studies have showed that Mortierellaisabellina M6-22 was characterized by cold adaptation.Thus the technique of mRNA differential display was used to analyze,the differentially expressed genes responding to low temperature in M6-22.Total RNAs of M6-22 cultured at15? and 30?,respectively,were extracted and subjected to RT-PCR using random combination between 9 anchored primers and 10 arbitrary primers,and the PCR products were seperated by denatured polyacrylamide gel electrophoresis.48 differentially displayed fragments ranging from 250bp to 1600bp were isolated and sequenced.After analyzed with GenBank to eliminate the redundant sequences,35 sequences were identified.A further Real time fluorescent quantitative PCR was uesed to verify the differentially expressed genes,and finally 21 genes were conformed.Among them,16 genes were up-regulated and 5 were down-regulated at 15?.BLAST analysis of these sequences showed that the coding proteins of thisdifferentially expressed genes include hydrolase,transferase,ligase,ATP binding protein,GTPbinding protein transporter,unknown and hypothetical protein;locating in cell membrane,organelles,cytoplasm,nuclei and cytoskeleton.Geneontology analysis indicated that these coding proteins were involved in synthesisof cell components,carbohydrate metabolism,nucleic acid metabolism,protein metabolism organic acid metabolism,modification and translation of proteins,transcriptional,regulation,translocation and others.This is study explored the mechanisms by which the genes expression were regulated in M.isabellina at low temperature,which will be helpful for further understanding of the response mechanism of M.isabellinaat low temperature and for further industrial application of M.isabellina M6-22 to produce useful products.