FIG 4.

Analysis of sulfur metabolism in E. huxleyi CCMP3266. (a) A sulfate ion permease gene exhibited high transcript abundance in dividing cells (day 06) and decreased as cultures aged. (b and c) Genes involved in reductive sulfate assimilation (b) and DMSP synthesis (c) exhibited the highest expression at stationary phase (day 9). Gene G28044 was identified as DSYB (methylthiohydroxybutryate methyltransferase), which catalyzes the last step of DMSP synthesis (99.7% amino acid identity), with the E. huxleyi CCMP1516 DSYB sequence reported by Curson et al (103). Information provided above the graphs include strain CCMP3266 gene annotations (bold), GeneID (red), and locus tag names of CCMP1516 homologues genes (gray). CCMP3266 GeneID, transcript IDs, and functional annotations are listed in Data Set S2; nucleotide sequences can be retrieved from Data Set S1, using the respective GeneID and/or transcript IDs.