Calcium ion influx during sporulation in the yeastSaccharomyces cerevisiae

Abstract

The changes in intra- and (or) extra-cellular concentrations of Ca2+, Mg2+, K+, and Na+during sporulation of a MATa/MATα diploid yeast of Saccharomyces cerevisiae were examined in a nutrition-deprived medium with potassium acetate. Among these, Ca2+in external medium was preferentially incorporated into cells, and sporulation was induced when the magnitude of free Ca2+gradient between cytosol [Ca2+]iand external medium [Ca2+]oreached more than 3 × 103([Ca2+]i/[Ca2+]o = 3.5 × 103). The result indicated that the meiosis and (or) sporulation signal of the yeast S. cerevisiae was generated through elevated Ca2+influx rather than release from the internal Ca2+stores.Key words: Saccharomyces cerevisiae, calcium signalling, Ca2+influx, meiosis, sporulation.