Expression Profiles of delta 6 and delta 12-Fatty Acid Desaturase Encoding Genes Cunninghamella bainieri during Gamma-Linoleneic Acid Biosynthesis

Delta 6-fatty acid desaturase and delta12-fatty acid desaturase are enzymes required for the desaturation steps during gamma-linolenic acid (GLA) biosynthesis in oleaginous fungi. The objectives of this study were to analyse the expression profiles of genes which encode for the delta 6-fatty acid desaturase (des6) and delta 12-fatty acid desaturase (des12) from an oleaginous fungus, Cunninghamella bainieri, during GLA production. Partial gene sequences with the size of 1372 bp for des6 and 1008 bp for des12, were isolated from C. Bainieri. Gene expression analyses via real-time quantitative PCR (RT-qPCR) indicate that the changes in the expression profile of des6 is higher during GLA production as compared to the expression profile of des12. The expression of des6 is the highest after 24 h of growth in the GLA-inducing medium. However, its expression showed a decreasing pattern until 96 h of growth but increased at 120 h. The expression profile of des12 is more consistent with the highest expression levels detected at 120 h of growth. GLA production analysis showed that the amount of GLA in the cell is correlated with the expression of des6. The results of this study suggested that the expression of des6 plays an important role in determining GLA production in C. bainieri.