Presenter(s): Alina Salagean—Biology
Faculty Mentor(s): Erik Toraason, Diana Libuda
Session 6: Interact & React
Most organisms utilize meiosis, a specialized form of cell division, to produce reproductive cells such as sperm and eggs . Failure to maintain genomic integrity during meiosis can result in serious diseases, including infertility and cancer . The Structural Maintenance of Chromosomes 5/6 complex (SMC-5/6), its E3 SUMO ligase subunit NSE-2, and the BRCA1/BARD1 heterodimer are conserved protein complexes implicated in ensuring accurate meiotic DNA repair and are known to genetically interact . However, the specific mechanisms by which these proteins interact to preserve genome integrity is unknown . To determine the NSE-2 specific and NSE-2 independent meiotic functions of the SMC- 5/6 complex in meiotic DSB repair, we utilized immunofluorescence imaging and a mortal germline phenotype assay to assess smc-5 and nse-2 C . elegans mutants . Our findings suggest a separation of function within the SMC-5/6 complex, which performs NSE-2 dependent functions promoting efficient meiotic DSB repair and NSE-2 independent functions in preservation of germline immortality . Finally, to define epistatic relationships between BRC-1/BRD-1, SMC-5/6, and NSE-2 in DNA repair, we assessed the germline sensitivity to exogenous DNA damage by scoring the brood viability of pairwise brc-1, smc-5, and nse-2 double mutants . These data reveal that exogenous DNA damage repair is differentially regulated within meiotic prophase I and implicate SMC-5/6 as a central regulator of both NSE-2 and BRC-1 dependent DSB repair . Taken together, our research defines fundamental genetic mechanisms and interactions preserving genomic integrity .