Biology

Dr. Anjana Badrinarayanan
Massachusetts Institute of Technology, Cambridge, USA

DNA double-strand breaks (DSBs) are a threat to genome stability and unrepaired or incorrectly repaired DSBs can lead to loss of genetic information and cell death. Hence, cells in all domains of life have evolved conserved mechanisms to repair DSBs via homologous recombination. While the process of recombination has been well-studied biochemically, its spatial organization and regulation inside cells is less understood. In this study site-specific DSBs were introduced at various locations across the chromosome of the bacterium, Caulobacter, and DSB processing and repair were probed using time-lapse microscopy and deep-sequencing techniques. I will first describe the spatial organization of the repair process and how it is coordinated with chromosome replication, organization and segregation. I will then discuss a novel assay to measure DSB processing in vivo and the mechanisms by which this processing is regulated. Together, these studies provide important insight into the effect of DSBs on chromosome organization and segregation as well as the mechanisms used by cells to ensure that genomic integrity is maintained during the repair process.