Prymnesium parvum strain:Texas Transcriptome or Gene expression
Few high-thoroughput RNA sequencing (RNA-seq) studies investigating the osmoregulation of euryhaline algae exist in the literature to date. A number of these marine algae are used for the production of biodiesel and polyunsaturated fatty acids (PUFAs), which have not yet been well studied in Prymnesium parvum (P. parvum). We report here the first RNA-seq analysis of the transcriptome of P. parvum, which is a euryhaline haptophyte that forms toxic blooms that are of global significance. Sequence assembly using the Trinity software generated 47,297 transcripts, of which 35.3% were identified with BLAST, and 31.5% and 16.8% were classified into gene ontology (GO) categories and KEGG pathways, respectively. Transcripts involving osmoregulation, transport and fatty acid metabolism (in relation to the synthesis of triacylglycerols (TAGs), PUFAs and ichthyotoxins) were particularly focused on. The comparative analysis revealed the differential expression of 2,507 transcripts (6%); 1,507 up- and 1,000 downregulated at 30 versus 5 psu. GO terms involving transport and membranes were downregulated at 30 psu, and those involving cell stress were upregulated. Sequence level assessments indicated the differential expression of several participants in the glyoxylate cycle, fatty acid synthesis, TAG synthesis, ion and vesicular transport and osmolyte production. Additionally, a number of parallels were made with other studies in the literature involving the osmoregulation of eukaryotic algae at the transcript level. These data provide the most comprehensive characterization of the P. parvum transcriptome to date and shed light on the transcriptional responses that occur following alterations in salinity.