A Screen for Schizosaccharomyces pombe Mutants Defective in Rereplication Identifies New Alleles of rad4+, cut9+ and psf2+

Abstract

Fission yeast mutants defective in DNA replication have widely varying morphological phenotypes. We designed a screen for temperature-sensitive mutants defective in the process of replication regardless of morphology by isolating strains unable to rereplicate their DNA in the absence of cyclin B (Cdc13). Of the 42 rereplication-defective mutants analyzed, we were able to clone complementing plasmids for 10. This screen identified new alleles of the APC subunit cut9+, the initiation/checkpoint factor rad4+/cut5+, and the first mutant allele of psf2+, a subunit of the novel GINS replication complex. Other genes identified are likely to play general roles in gene expression and protein localization.