Award: PLR-1341362

Intellectual merit Kleptoplasty is the temporary acquisition of functional chloroplasts by a normally heterotrophic cell. Previously, we identified a novel kleptoplastidic dinoflagellate that is very abundant in the Antarctic marine environment. Unlike most other kleptoplastidic associations, it is stable for up to 5 months without reacquisition of new chloroplasts. Algae play an important role in the fixation of CO2 in the Southern Ocean, and because of the abundance of this particular organism, we wanted to better understand how the dinoflagellate might control the kleptoplast. We used high throughput sequencing of RNA isolated from cells under different conditions of temperature and light to identify the genes involved in kleptoplast regulation, as well as the evolutionary history of those genes. We determined that the dinoflagellate hosts a non-photosynthetic peridinin plastid in addition to the kleptoplast, and that it expresses and targets plastid related genes to both organelles. While transcripts related to cell metabolism, DNA replication and growth show differential expression under different environmental conditions, the plastid-associated transcripts do not. We also discovered that the kleptoplast showed a substantial decrease in photosystem II activity, suggesting reliance on photosystem I. This was supported by our observation of dinoflagellate expressed nuclear-encoded, plastid-targeted photosystem I associated transcripts. We propose that the reduction in oxidative damage by decreasing PSII activity, along with the support of PSI by the dinoflagellate, may help to prolong the life of the kleptoplasts. Broad impacts In addition to publishing papers and presenting at meetings, I have participated in several outreach activities. I collaborated with a graphic arts teacher at Falmouth High School to incorporate Antarctic science images into their artwork. In the classroom I gave a short presentation on Antarctica and what research I have been doing regarding microbes in general, followed by questions from the students. The students were then allowed to choose images of plankton for a watercolor project and images of Antarctic scenery for a linoleum cut printing project. The students were not only to learn techniques, but to reflect the scientific work and incorporate characteristics of the polar region such as the dramatic lighting and frozen environment. Completed art was exhibited at the Falmouth High School Science Fair in February 2016, and as an exhibit in the WHOI Exhibit Center in May 2016. I also talked to several third grade classes about Antarctica during their study of penguins. In addition to lots of penguin images, I showed pictures of how scientists travel to Antarctica and how research is conducted onboard the RVIB NB Palmer. Most recently, I interacted with local Girl Scout Troops in their pursuit of Oceanography Badges. I gave a 20 minute 'Introduction to Oceanography' presentation that described the different fields studied by oceanographers and briefly introduces the first oceanographic expeditions. This was followed by a 15-20 minute presentation my own research experiences in Antarctica and questions from the scouts (another 30 minutes). Last Modified: 02/01/2018 Submitted by: Rebecca J Gast