Elucidation of Functional Genes Associated with Long Chain-Polyunsaturated Fatty Acids (LC-PUFAs) Metabolism in Oleaginous Diatom Phaeodactylum tricornutum

Abstract

Phaeodactylum tricornutum is a marine diatom rich in omega-3 fatty acids, a nutraceutical-relevant product. Long chain-polyunsaturated fatty acids (LC-PUFAs) are crucial dietary components for human development and growth. With the availability of genome information and genetic engineering tools, the productivities of OMEGAs have improved, but the functional and organizational relationship of such protein-encoding genes associated with LC-PUFAs biosynthesis is still not clear. Henceforth, our study highlights the conservation pattern, functionality and interaction of LC-PUFAs protein-encoding genes via in silico analysis. The transcriptome and quantitative PCR analysis demonstrates downregulation of ACS4, ELO6b, PTD5a, and MYB106 genes associated with LC-PUFAs synthesis and upregulation of ECoAH and ACAT1 genes associated with β-oxidation in nitrogen-depleted conditions in P. tricornutum. Phylogenomics studies of LC-PUFAs protein-encoding genes show a highly conserved evolutionary pattern in various microalgal lineages. Further, for elucidating the interaction of LC-PUFA metabolic genes, subcellular networks were predicted and pathway enrichment analysis was performed, providing new insights on the crosstalk between LC-PUFA protein-encoding genes (ELO6, PTD5, ACS, and ACL1), regulatory elements (LEC2, MYB, WIN) and transporters (ABCD1). In conclusion, such extensive functional enrichment analysis will undoubtedly aid in the development of genetically engineered algal strains with enhanced production of biomolecules i.e., LC-PUFAs.