Molecular and genome biology of dinoflagellate protists

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Dinoflagellates are single-celled microbes notorious for their important ecological roles in aquatic habitats. In addition to their roles as primary producers and nutrient recyclers, they are involved in phenomena of global scale such as toxic algal blooms (e.g. red tides), reef-forming coral symbioses and crustacean and fish diseases. The biology of dinoflagellates is extraordinary in many ways. Perhaps the most conspicuous aspects found in the literature is their extremely large genome size, which in certain species can reach a hundred times the human genome, and the enigmatic nature of their cell nucleus which is in some ways very different from the standard eukaryotic nucleus. It is still unclear how these particularities originated and evolved. This research program is addressing aspects of the enigmatic biology of dinoflagellates. For this, we are conducting genome sequencing of the cosmopolitan dinoflagellate Oxyrrhis marina. With this information we will conduct an encompassing analysis of mobile genetic elements (a.k.a transposable elements) across several species of dinoflagellates. These elements are pieces of DNA with the ability to replicate and `jump' to other parts of the genome. Such elements exist in many organisms including animals and plants and can, through their activity, affect gene function and cause evolutionary change. We found that dinoflagellate genomes are rich in certain types of mobile elements and we hypothesize that they could help explain the large genomes size in dinoflagellates. Our analysis will reveal in what ways and how much do mobile elements affect genome function and evolution. In addition to mobile elements we will be exploring other aspects of the genome and nucleus. One of the most conserved features among eukaryotes is the way in which DNA organizes in 3D structures by associating with a type of proteins known as histones. This highly structured mix of DNA and proteins, known as chromatin, is remarkably different in dinoflagellates but the details are poorly known. We will investigate in detail the molecular organization of chromatin and chromosomes in dinoflagellates looking to understand how proteins and DNA interact during the different phases of the cell cycle, and how this determines anc controls essential processes such as cell division and gene expression. Completion of this project will generate positive impact for Canada in various levels. It will help strengthen Canada's reputation of a leader in genomics and molecular biology of microbial eukaryotes. Advancement of research on marine microorganisms aligns with Ocean Research, one of the top priorities for my institution, Nova Scotia and the Federal Government. Finally, the work involved in this proposal contains ample opportunities for basic and advanced training in cutting edge research in bioinformatics, genomics and molecular biology, contributing to a stronger and highly skilled workforce that feed both industry and academia.