NSF Award
2122072
The overall goal of this project is to study how cells maintain the stability of their genomic DNA. Mutations can arise in genomes due to natural failures during DNA replication or can be induced by environmental factors such as radiation and certain chemicals; mutations promote cancer, aging, neurodegenerative and other diseases, hence it is important to understand their genesis and processing. Some frequent “hotspot” mutations arise during stalled replication, when the nascent DNA strand wanders and finds a wrong strand to copy. This “template-switch” event is the main subject of this project. The aims are to determine what genes influence the frequency of such mutation events and what chemicals or other environmental factors might promote them. A broader impact goal is to train students from diverse backgrounds on how to conduct scientific research, using a simple organism, budding yeast, that can be easily grown and genetically manipulated in the laboratory. A project lab will be developed to introduce students with no prior experience to research practice and techniques, in a supportive and mentored environment. <br/><br/>Genetic assays for template-switch mutations at imperfect inverted repeats in DNA have been engineered in yeast and will be used to identify genes that influence mutagenesis. Preliminary evidence suggests that double-strand DNA breaks frequently undergo template-switching during repair. The HO endonuclease-induced mating-type switching system will be used to study template-switching during DNA replication events that accompany double-strand break repair. Template-switching during normal replication will also be examined for comparison. Finally, potential mutagens will be screened using the template-switch reporter system. The outcomes will increase knowledge about the mechanisms of mutagenesis and its avoidance, and provide valuable information about DNA processing associated with replication difficulties and how replication is coordinated with repair.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
