Transcriptome analysis of Chlamydomonas reinhardtii during the process of lipid accumulation.

Algae are potential candidates for biodiesel production; thus, it is important to gain insight into the molecular mechanism of their lipid metabolism. Time-course transcriptome analyses were carried out during the lipid biosynthesis and accumulation processes of the model green alga Chlamydomonas reinhardtii using the Illumina RNA-seq platform. Transcriptome results indicated that over 2500 genes are upregulated or during lipid accumulation compared to log phase growth. As a proof of principle, two of the enzymes required for lipid metabolism that were significantly up-regulated during lipid accumulation, Lyso-Phosphatidic Acid Acyltransferase (LPAAT), diacylglycerol acyltransferase (DAGAT) were knocked down using artificial microRNAs. Neutral lipid production decreased in strains knocked down in expression of the lpaat and dagat genes. In addition, forty-one transcription factors were up- or down-regulated during the lipid accumulation process. This transcriptome data will be useful for engineering economic algae species aimed at biodiesel production.