2023 36 B2

Characteristics and Kinetics of Chromosome Breakage in Fission Yeast S. pombe

By: Jiayu Luo

Department: Biology

Faculty Advisor: Dr. Sally Pasion

Chromosome breakage often leads to cell death or increased susceptibility of cancer development. In our study, we present the cdc24 mutants in fission yeast (S. pombe) showed chromosome breakage and loss of cell viability at the restrictive temperature (34°C). The phenotype of chromosome breakage is also observed in other conserved DNA replication genes, such as cdc17 (encoded DNA ligase I) and dna2 (encoded endonuclease Dna2). At the permissive temperature, FACS (fluorescence-activated cell sorting) analysis showed both cdc24 and cdc17 mutants had more cells delayed in S phase. However, our PFGE (pulsed-field gel electrophoresis) analysis showed that cdc24 mutant cells that were enriched in S phase (45%) did not show chromosome breakage phenotype at the restrictive temperature. These results reveal the possible roles of cdc24 in DNA replication and chromosome integrity. Studying chromosome integrity during DNA synthesis opens up possibility of new cancer diagnosis and treatment.