The cdc18(+) gene of the fission yeast Schizosaccharomyces pombe is involved in the initiation of DNA replication as well as in coupling the S phase to mitosis. In this work, we show that the Saccharomyces cerevisiae CDC6 gene complements cdc18-K46 ts and cdc18 deletion mutant S. pombe strains. The budding yeast gene suppresses both the initiation and the checkpoint defects associated with the ...