Constructing a Robust Multi-Gene Phylogeny and Studying Host and Plastid Evolution in the Alveolate Protist Dinoflagellata

University Of Connecticut, Storrs CT

Investigators

Abstract

0344186 Lin Dinoflagellata are microscopic organisms that are critical to the marine ecosystem. While they are food for fish and other animals, some of them are life support of coral reefs, and many of them cause environmental problems by forming red tides. Due to the ecological and economical significance, understanding the evolution and diversification of these organisms is of high interest. Research by Senjie Lin and Huan Zhang at the University of Connecticut is focused on studying phylogenetic relationships among these organisms using nuclear (ribosomal DNA) and mitochondrial gene sequences for a wide span of dinoflagellate species. Sequences of these genes will be determined using PCR-based cloning and automated sequencing, and phylogenetic trees will be constructed using various methods to study dinoflagellate evolution. Specific objectives of this project include 1) identifying early-diverging lineages of dinoflagellates and reconstructing the radiation pattern for dinoflagellates; 2) assessing when the coral reef symbiont life-style emerged during dinoflagellate evolution; 3) studying how dinoflagellates diversified their trophic pathways; and 4) assessing how toxic species evolved. Results from this proposed project will constitute the first broadly based sampling of multiple genomes for many species of dinoflagellates and will provide a robust phylogenetic framework for this important group of organisms. Insights will be obtained from this project regarding dinoflagellate relationships with closely related organisms like the malaria parasite Plasmodium. Furthermore, novel information valuable for policy making in coastal environment management and conservation is expected. This project will also broaden graduate student training and enrich the curriculum for courses through integration of the discoveries into the curriculum. In particular, the results from this study will help students to appreciate how diverse and complex these seemingly simple microorganisms can be and how powerful molecular tools can be used in answering basic evolutionary questions. Finally, this grant will enable the PIs to continue with their commitment to encourage minority and female students to participate in scientific research.