Identification of mutants with increased chitin content. Depicted histograms correspond to flow cytometry analysis of yeast cells after treatment with the chitin-binding fluorescent dye, Calcofluor white (5 μg/ml for 10 min). Representative experiments of mutants are shown in which chitin content was found to be higher compared to the wild-type strain. For each mutant (blue line), a histogram corresponding to the wild-type strain (filled area) handled in parallel is included in each representation. The name of genes functionally related to cell wall integrity and morphogenesis is underlined. "RM" refers to the ratio of means of fluorescence intensity for each cell population (mutant/wt).