A large-scale sonication assay for cell wall mutant analysis in yeast

The complete yeast genome contains a large number of genes of unknown biolo gical function. Simple, rapid and reliable specific screens are valuable to ols in exploring gene function via systematic phenotypic analysis of large mutant collections. This report provides a new approach for monitoring chan ges in cell wall strength, based on the deleterious effects caused by ultra sound on the yeast cell surface. Sonication can thus be used for the screen ing of mutants affected in the architecture or stability of the cell wall, since such mutants are expected to have an altered sensitivity to this trea tment compared to that of a wild-type. The experimental procedure, consisti ng in the quantification of damaged cells after a mild sonication treatment , by means of flow cytometry, can be applied on a large scale. The usefulne ss of the sonication assay as a primary screen for cell wall-related mutant s is evaluated on the collection of calcofluor white-hypersensitive and -re sistant mutants obtained by Lussier et al. (1997). A further phenotypic cha racterization of the sonication-hypersensitive mutants within the calcofluo r white collection is also presented. Copyright (C) 1999 John Wiley & Sons, Ltd.