Abstract
The marine diatom Phaeodactylum tricornutum is expected to be a source of hydrocarbons and carotenoids that are synthesized via isoprenoid precursor biosynthesis pathways such as the mevalonate (MVA) and the 2-C-methyl-D-erythritol phosphate (MEP) pathways, because the molecular biotechnological techniques for metabolic engineering have been established. In this study, we investigated the expression profiles of the genes, including those in the MVA and MEP pathways, under various culture conditions using RNA-seq analysis to obtain information useful for the metabolic engineering and development of endogenous promoters that can highly drive the expression of transgenes in P. tricornutum. The expression levels of the genes in the MVA pathway, except for the 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) gene, were low under all the conditions tested, and the expression levels of the 4-diphosphocytidyl-2-C-methyl-D-erythritol kinase (CMK) and 2-C-methyl-D-erythritol 2,4-cyclodiphosphate synthase (MDS) genes in the MEP pathway were relatively low. Eleven genes with high expression levels, including the V-type proton ATPase subunit C-like gene, which are potential sources of endogenous promoters in P. tricornutum, were selected. These results are expected to provide useful information for the metabolic engineering of P. tricornutum.
