ABSTRACT
OBJECTIVE: To determine whether cell cycle changes can be detected in myosin II-deficient cells using flow cytometry techniques. BACKGROUND: Although the primary role of myosin II (Myo1p) in the yeast Saccharomyces cerevisiae is in cytokinesis we have reported that this conventional myosin also appears to inuence the regulation of cell wall metabolism as indicated by increases in the expression of chitin metabolizing enzymes in a null mutant of the MYO1 gene. The expression of these enzymes is known to be regulated in the cell cycle suggesting that cell cycle changes may alter their expression. METHODS: Flow cytometry was employed to assess the nuclear DNA content of logarithmic yeast cell cultures as a means of determining changes in the cell cycle of Myo1p-deficient cells. RESULTS: Significant changes were observed in the Myo1p-deficient strain suggesting that these cells are arrested in G2/M-phase of the cell cycle. CONCLUSIONS: Based on the results of this preliminary study, we propose a model in which the increased activity of chitin metabolizing enzymes may be explained by a mitotic arrest in these cells.