Biochemical and bioinformatics approach to the study of lipids and their biosynthetic pathways in Chromera velia and Vitrella brassicaformis

dc.contributor.advisor Leblond, Jeffrey en_US Khadka, Manoj en_US
dc.contributor.committeemember Farone, Anthony en_US
dc.contributor.committeemember Robertson, James en_US
dc.contributor.committeemember Walck, Jeffrey en_US
dc.contributor.committeemember Seipelt-Thiemann, Rebecca en_US
dc.contributor.department Biology en_US 2014-08-28T18:42:54Z 2014-08-28T18:42:54Z 2014-07-11 en_US
dc.description.abstract Vitrella brassicaformis and Chromera velia are marine microalgae that photosynthetic plastids of red algal origin, are closely related to non-photosynthetic apicomplexan parasites and are classified as the phylum Chromerida and familes Vitrellaceae and Chromeraceae, respectively. To dates, only one study has been performed on the galactolipid of Chromera velia and few other studies have been based on the ultrastructural and phylogenetic studies in Chromerida. We used a combination of mass spectrometry techniques and RNA-seq data to elucidate the sterol and galactolipid composition of the Chromerida, and to identify their biosynthetic genes, respectively. The identified genes were further utilized to perform the gene phylogenies of the Chromerida with red algae, dinoflagellates and apicomplexans. en_US
dc.description.abstract Sterols are amphipathic, ringed lipids that are synthesized mostly by eukaryotes and few prokaryotes via mevalonate and/or non-mevalonate pathways. Some of the major functions of sterols include regulating membrane dynamics, hormonal activity, and acting a secondary messengers in developmental signaling. C velia produces two primary sterols 24-ethylcholesta-5,22-dien-3β-ol, and 24-ethylcholest-5-en-3β-ol, not common to dinoflagellates, but commonly found in other groups of algae and plants. Three sterol biosynthetic genes- sterol-24C-methyltransferase (smt1), farnesyl diphosphate farnesyl transferase (fdft1), and isopentenyl diphosphate isomerase (idi1) were identified after expressed sequence tag (EST) analysis in C. velia. V. brassicaformis produces two sterols 24-ethylcholest-5-en-3β-ol and an unknown C26:2 sterol along with several biosynthetic genes related to the non-mevalonate pathway for sterol biosynthesis. en_US
dc.description.abstract The galactolipids, MGDG and DGDG, are the major plastid structural lipids in all photosynthetic organisms that play a role in the organization of thylakoid membrane providing stability to the photosystem I and II complexes in chloroplast. V. brassicaformis produces a diversity of galactolipids that primarily contained C20/C14, C20/C16, and C20/C18 (sn-1/sn-2 regiochemistry) fatty acid components attached to the glycerol moieties of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacyl glycerol(DGDG). These forms of MGDG and DGDG are different and structurally more diverse than the previously identified C20/C20 forms that compose nearly the entirety of C. velia's MGDG and DGDG. en_US
dc.description.abstract The sterol and galactolipid diversity between these chromerids indicates possible differences in their biosynthesis. I also also present hypotheses for how other aspects of the galactolipid biosynthesis pathways, namely fatty acid elongation and desaturation, in the Chromerida must differ prior to the addition of galactose to MGDG and DGDG. en_US Ph.D. en_US
dc.publisher Middle Tennessee State University en_US
dc.subject Apicomplexan en_US
dc.subject Chromera velia en_US
dc.subject Chromerida en_US
dc.subject Galactolipid en_US
dc.subject Sterol en_US
dc.subject Vitrella brassicaformis en_US
dc.subject.umi Molecular biology en_US
dc.subject.umi Microbiology en_US
dc.subject.umi Biochemistry en_US
dc.thesis.degreegrantor Middle Tennessee State University en_US
dc.thesis.degreelevel Doctoral en_US
dc.title Biochemical and bioinformatics approach to the study of lipids and their biosynthetic pathways in Chromera velia and Vitrella brassicaformis en_US
dc.type Dissertation en_US
Original bundle
Now showing 1 - 1 of 1
No Thumbnail Available
3.07 MB
Adobe Portable Document Format