Recruitment and dynamics of DNA repair proteins at sites of complex DNA damage within the Caenorhabditis Elegans germline
Year: 2021
Type: dissertation
Abstract: DNA double-strand breaks (DSBs) are one of the most complex and toxic forms of DNA damage in which both strands of DNA are broken at the same time. Improper repair of DSBs can lead to the formation of mutations. This is particularly important for the germline since mutations in germ cells are passed on to the next generation. The choice between different repair mechanisms is an important point in dictating whether a mutation will be formed and how deleterious it is. Therefore, understanding the regulation of different repair mechanisms and the choice between them is important in determining how mutations are formed in the germline. This thesis in particular investigates how DSBs induced by irradiation are dealt with in this meiotic context in a way that produces viable gametes. Our lab uses the model organism Caenorhabditis elegans, a small, transparent nematode. We developed a method of inducing DSBs in a localized position in the nucleus of the cell by laser microirradiation. We induce DSBs in the germline of whole, live worms, and through the use of fluorescent protein tags, we are able to examine the recruitment of DSB repair proteins from time of damage induction within a live organism. By employing this methodology, we gain insight as to how recruitment of repair proteins is modulated throughout the germline, and how this recruitment may be influenced by other repair factors. In this thesis I present evidence for recruitment of repair factors in the two main DNA repair pathways to microirradiation-induced DSBs in a way that is specific to different regions of the germline. Our work indicates that regulation of DNA repair at sites of microirradiation-induced DSBs is unique from the type of regulation which occurs at DSBs induced by internal cellular processes. This thesis also presents evidence for the increased movement of DNA following damage induction, and the localization of DSB sites to the nuclear periphery over time. The research presented here provides valuable insight into the differences in regulation of DNA repair that occurs at differing forms of DSBs within a meiotic context.
DOI: 10.17077/etd.005775
Authors: Kailey Elizabeth Cash, Sarit Smolikove, Anna Malkova, Bryan Phillips, Maria Spies, Marc Wold
Language: English
Topic: DNA Repair Mechanisms
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W4231491764