Grant: Operating Grant

Our genetic make-up consists of two equal sets of chromosomes inherited from our mother and father, such that most genes are present as two equivalent copies in our cells. However, some unusual genes in our genome behave differently: for these genes, only one of the two copies is used by our cells, depending on its parental origin. Why or how these particular genes are not active from both copies is not fully understood. This phenomenon, called genomic imprinting, is essential for normal development of the mammalian embryo and is linked to several human diseases, with more than 200 newborns affected each year in Canada, and cancers. Our research program tries to understand how this imprinting works and what might be its function in mammalian biology. To this end, we are studying new models of imprinting defects, using the mouse as a model system. We recently established the first mouse line expressing the green florescent protein under the regulation of imprinting: the fluorescent gene is silenced upon transmission through the paternal germline. We have also developed a new technique allowing us to study maternal and paternal copies of an imprinted domain independently, in the hope of identifying the molecular marks used by our cells to distinguish paternal and maternal copies of these genes in the genome. We are using these unique tools to study the mechanism of imprinting in a mammalian model organism. Through our work we will gain a better understanding of how some of our genome is utilized during development and how we might help patients where imprinting abnormalities have occurred. By contributing to further knowledge on the epigenetic mechanisms regulating our genome, this research also has important implications for area such as reproductive technologies and stem cell research.