PhD student in the School of Marine & Atmospheric Sciences
'Horizontal gene transfer in the carotenoid production pathway of a non-photosynthetic marine protist'
Synopsis: In photosynthetic organisms, carotenoid pigments have functions for light-adapted lifestyles: light absorption and photoprotection. However, carotenoids are also produced in non-photosynthetic organisms, where both the function and evolution of these pigments is more mysterious. To gain insight into the function of carotenoids in non-photosynthetic organisms, I am studying the evolution of a gene involved in the first step of carotenoid biosynthesis in single-celled marine eukaryotes known as thraustochytrids. My phylogenetic analyses suggest that this gene, which encodes a phytoene synthase domain and is involved in condensing two geranylgeranyl pyrophosphate molecules to make phytoene, was acquired via horizontal gene transfer from bacteria. Having co-opted carotenogenesis via horizontal gene transfer suggests a significant fitness implication and potentially unique function pertaining to thraustochytrids, and potentially extending to other non-photosynthetic eukaryotes as well.
Biography: Mariana Rius fell in love with marine science when her parents encouraged her to (not-so-willingly)
attend a John’s Hopkins University Center for Talented Youth (CTY) summer program
after eighth grade which focused entirely on the Chesapeake Bay oyster. She became
a marine conservation volunteer for Projects Abroad in Thailand following high school
graduation. Mariana completed her BS at the College of Charleston, SC. Her summers
were filled with diverse research internship projects at the NIH, where she continued
to do a two-year post-baccalaureate intramural research training award (IRTA) fellowship
in the National Eye Institute. She began her PhD in the School of Marine and Atmospheric
Sciences in August 2014 working on a very understudied
but critical protist found all over the world’s oceans.
Monday, October 16, 2017 at 12:30 PM