INVESTIGATING THE GENOMIC COMPOSITION OF OXYRRHIS MARINA, AN EARLY DIVERGING DINOFLAGELLATE

Abstract

Dinoflagellates are microbial eukaryotes with unique nuclear and mitochondrial genome organization. Their nuclear genomes are large and rich in repetitive elements and redundant gene copies, including retrogenes derived from mRNA retrotransposition. Conversely, their mitochondrial genomes are fragmented and gene-poor. Limited genome sequencing for this group of protists impedes a full understanding of both genome organization. This thesis focused on exploring both the nuclear and mitochondrial organization of Oxyrrhis marina, an early diverging dinoflagellate. Approximately 22% completeness was achieved, revealing 40% repeat content, and LTR retrotransposons were highly abundant. Tandem gene arrays and unidirectional gene orientation were observed alongside endogenized viral elements. O. marina's mitochondrial genome comprises three chromosomes with multiple gene copies and novel gene arrangements. On the other hand, retrogenes’ functional diversity reflected common dinoflagellate cellular processes.