Grant: Discovery Grants Program - Individual

The ciliate protozoan <em>Tetrahymena thermophila</em> undergoes novel large-scale programmed DNA rearrangements during the course of its sexual development. The underlying mechanism of these genome rearrangements is largely unknown except for the requirement of specific chromatin configurations whose assembly is directed by small RNAs (sRNAs) processed from meiotic, nucleus-wide transcription of non-coding RNAs (ncRNAs). The <strong>long-term objective</strong> of my research is to completely understand the mechanism and function of these large-scale DNA rearrangements. Because the connections between sRNAs, ncRNAs and chromatin related proteins are widespread in eukaryotic biology, I expect that acquiring knowledge concerning their mechanism and regulation in <em>Tetrahymena</em> will yield novel information on proteins and molecular pathways that are fundamental to all eukaryotes, including humans. In <strong>the short-term </strong><span style=""line-height: 1.5em;"">we will identify the underlying mechanism of transcription of ncRNAs from the meiotic nucleus of </span><em>Tetrahymena</em><span style=""line-height: 1.5em;"">. Because the mechanisms and proteins involved in the transcription of any DNA sequence in <em>Tetrahymena</em> is poorly understood, we have adopted a targeted proteomic approach to identify the set of protein complexes that function in transcription. Next we will identify the mode(s) of regulation of RNA polymerase II (RNAPII), the engine of transcription, at protein coding genes in growing <em>Tetrahymena</em>. Finally, we will determine how RNAPII is regulated at the unique DNA sequences that are transcribed into ncRNAs during <em>Tetrahymena</em> meiosis. In the longer term we will leverage our acquired knowledge in order to understand connections between newly transcribed ncRNAs, the cell's RNAi machinery, and chromatin assembly/remodeling pathways.</span><em><br /> </em><strong>Significance</strong>: Genome instability is often associated with random chromosome rearrangements. <em>Tetrahymena</em> is an experimental model that has the unusual property of undergoing developmentally regulated reproducible DNA rearrangements on a genome-wide scale. Understanding how <em>Tetrahymena</em> rearranges its chromosomes will increase general knowledge concerning DNA rearrangements and therefore this research is of fundamental importance and could lead to the identification of new marker proteins relevant to human cancer. For this reason, this research is potentially of long-term benefit to Canada's pharmacological and biotechnology industries.<br /> <strong>Training</strong>: The proposed research program will train four graduate students and multiple undergraduate researchers in fundamental molecular biology and molecular genetic methods as well as powerful new technologies such as Next Generation Sequencing. Collectively these methods compose the expertise required by the next generation of basic researchers and, increasingly, researchers in clinical and diagnostic laboratories and therefore this research will benefit to Canada's healthcare system