Comparative transcriptome analysis of yeast expressing the fungal desaturases

To study how the presence of PUFAs influences central cellular processes, and in order to perform lipidome, transcriptome and molecular studies we decided to use yeast as a model organism. We therefore co-expressed Δ12-desaturase and Δ6- desaturase genes from Mucor rouxii in S. cerevisiae with the objective to obtain a yeast strain that contains PUFAs, especially linoleic acid (LA, C18:2Δ9,12) and γ-linolenic acid (GLA, C18:3Δ6,9,12), in its membranes. The resulting yeast strain was analyzed in details in order to quantify the fluxes through the fatty acid biosynthetic pathways and the genome-wide transcriptional response to production of LA and GLA. Three recombinant yeasts were constructed and grown in glucose-limited condition. Steady-state cultures were harvested for RNA extraction and hybridization on Affymetrix microarrays. Comparative transcriptome analysis between S. cerevisiae recombinants expressing M. rouxii D12-desaturase (D12) and co-expressing D12-desaturase and D6-desaturase genes (D126) and the reference strain (REF) was implemented.