Using the GAL Locus as a Model System to Study Chromosome Dynamics

The spatial organization of the eukaryotic genome within the nucleus remains poorly understood. Studying chromosomal organization allows us to gain a more holistic understanding of transcription and other nuclear processes. Studies have shown that the spatial organization of chromosomes inside the nucleus is constantly changing as a response to external stimuli. A well-studied example is the migration of the GAL gene locus from the center of the nucleus to the nuclear periphery upon activation in Saccharomyces cerevisiae. Because the GAL gene locus is localized in chromosome II, the anchoring of the GAL gene locus to the nuclear periphery also displaces chromosome II. My project aims to identify how single genes move and how such genes' movement affects overall chromosomal organization. I will use the GAL gene locus as a model system to address these questions. The Weis Lab has generated a library of eighteen yeast strains with LacO copies that are spatially separated across chromosome II. This library along with green fluorescent proteins fused to LacI will be used to visualize chromosome II's mobility. To study the role of the GAL gene locus, I plan to remove it through homologous recombination in all eighteen yeast strains. Currently the first GAL gene locus knockouts are being generated. If the GAL gene locus fails to play a critical role in the movement of chromosome II, additional studies would be needed to determine what regulates chromosome II's movement. Our results will reveal novel insight in the organization and dynamics of individual chromosomes.