Grant: DRA: Canada Impact+ Research Training Awards - Doctoral

Complex genetic interactions occur when a combination of mutations in two or more genes results in an unexpected phenotype given the effect of individual mutations or lower-order combinations. Complex genetic interactions are prevalent and thus are thought to play a key role in the biology of inheritance. Mitochondrial carriers are nuclearly encoded, localize in the inner mitochondrial membrane and regulate the import and export of metabolites across the cytosol and mitochondrial matrix. Due to their function mitochondrial carriers play a key role in cellular metabolism and are associated with metabolic, cardiovascular and neurological diseases as well as cancer. However, their functional redundancy is poorly understood. Thus, I propose to use an integrative approach to systematically map the complex genetic interactions of the conserved eukaryotic gene family of mitochondrial carriers. First, I will use the budding yeast model organism to construct 249 double and 1206 triple mutant strains of all possible combinations of 23 yeast orthologs using trigenic-Synthetic Genetic Array (t-SGA). Second, I will use the in4mer CRISPR-enCas12a multiplex screening strategy in human cells to map the digenic and trigenic interactions of all possible pairwise (1,378) and triple (23,426) combinations of loss-of-function mutations of the 53 human orthologs. Third, I will leverage the UK biobank data to identify cases where multiple genetic variants of mitochondrial carriers in an individual’s genome increase their disease risk by establishing a systematic collection of high-confidence genetic interactions associated with metabolic indicators and circulating biomarkers. This study will illuminate the role of complex genetic interactions in the genotype-to-phenotype relationship.