Polycyclic aromatic hydrocarbons and small related molecules: Effects on Schizosaccharomyces pombe morphology measured by imaging flow cytometry

Effects of polycyclic aromatic hydrocarbons and small related molecules on the morphology of fission yeast (Schizosaccharomyces pombe) are described. Polycyclic aromatic hydrocarbons are important environmental pollutants that act as carcinogens via several mechanisms of action. Fission yeast is a useful model organism for revealing the mechanisms by which these molecules affect the cell. None of the molecules studied affected cell length of wildtype or a rad26D mutant yeast relative to control, indicating that none of these operate like known genotoxins that lengthen the cell. Five compounds are shown to decrease cell width in wildtype fission yeast, but not in the rad26D strain. These results indicate that machinery controlling the cell’s width is affected by these molecules, and that this change is not detected when the rad26 protein is absent. These observations were made using imaging flow cytometry, which captures tens of thousands of two-dimensional cell images in a short time and provides statistically rigorous data on large cell populations.   Key words: Fission yeast, Schizosaccharomyces pombe, hydrocarbon, polycyclic aromatic hydrocarbon (PAH), morphology, imaging flow cytometry.