Kleptoplast Regulation by an Antarctic Dinoflagellate

We are studying the evolutionary history and expression of plastid- targeted genes in an Antarctic dinoflagellate that steals chloroplasts from the haptophyte, Phaeocystis. Our project seeks to determine whether the kleptoplastidic dinoflagellate utilizes ancestral plastid proteins to regulate its stolen plastid, and how their transcription is related to environmental factors that are relevant to the Southern Ocean environment (temperature and light). To accomplish our goals, we have utilized high throughput transciptome analysis and RNA-Seq experiments of the dinoflagellate and Phaeocystis. Analysis of the dinoflagellate transcriptome has revealed complete mevalonic acid-independent and heme plastid-associated pathways as well as petF and petH transcripts with peridinin-plastid targeting sequences. In contrast, the proteins psaE, petJ, petC show similarity to non-Phaeocystis haptophyte homologs in their respective trees, and potentially carry haptophyte transit peptides. Anaylsis of RNA-Seq temperature and light experiments for the dinoflagellate indicate that there are significant differences in gene expression under the different environmental conditions, and we are in the process of identifying the genes associated with these changes. This work will help us to understand the environmental success of this alternative nutritional strategy.