Nosenko, Tetyana , Bhattacharya, Debashish .
Horizontal gene transfer in chromalveolate algae.
Horizontal gene transfer (HGT), the non-genealogical transfer of genetic material between different organisms, is considered a potentially important mechanism of genome evolution in eukaryotes. Using a high throughput phylogenomic analyses of expressed sequence tag (EST) data generated from a clonal cell line of the “Florida red tide” dinoflagellate alga Karenia brevis, we investigated the impact of HGT on genome evolution in chromalveolates. We identified 16 proteins that have originated in chromalveolates through ancient HGTs before the divergence of the dinoflagellate genera Karenia and Karlodinium and one protein that was derived through a more recent HGT. The identified proteins are involved in cell wall biogenesis, secondary metabolite biosynthesis, energy metabolism, substrate transport, and translation. Detailed analysis of the protein phylogenies and distribution demonstrates that nine have resulted from independent HGTs in several lineages of photosynthetic and heterotrophic protists. The results of this study suggest that recurring intra- and interdomain gene exchange provides an important source of genetic novelty in free-living eukaryotes. In niches where parasitism and phagotrophy are common, prokaryotic and eukaryotic microorganisms can be thought of as an interactive community meta-genome. Beneficial genes may spread rapidly among different components of this pool and provide a molecular basis for niche-specific adaptations. The contribution of HGT in chromalveolates is enhanced by multiple duplications of these foreign genes. Investigating the tempo and mode of evolution of horizontally transferred genes will advance our understanding of mechanisms of adaptation in algae.
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1 - University of Iowa, Biology, Roy J. Carver Center for Comparative Genomics, 460 Biology Building, Iowa City, Iowa, 52242, USA
2 - University of Iowa, Biology, Roy J. Carver Center for Comparative Genomics, 446 Biology Building, Iowa City, Iowa, 52242, USA
horizontal gene transfer
Presentation Type: Oral Paper:Papers for Sections
Location: Lake Michigan/Hilton
Date: Tuesday, July 10th, 2007
Time: 4:30 PM