Morphological Alterations of the Fission Yeast Schizosaccharomyces pombe in the Presence of Aculeacin A: Spherical Wall Formation

Abstract

The fission yeast Schizosaccharomyces pombe, grown in the presence of aculeacin A (Acu), an antifungal antibiotic, forms spherical rather than cylindrical walls. This aberrant morphogenesis was studied in the presence of Acu at 1 μg ml–1 under conditions in which over 90% of the cells continued to grow but with altered morphology. Microscopic observations and chemical analyses revealed that the spherical walls had a looser structure than the cylindrical wall and that their syntheses of alkali-insoluble glucan and mannan were reduced whereas the synthesis of alkali-soluble glucan was enhanced. Spherical walls of glutaraldehyde-fixed cells were hardly digested by Zymolyase 60000 [a (1→3)-β-glucanase] but were digested by Novozym 234 [a (1→3)-α-glucanase]. From these results the components and morphology of the spherical walls are discussed in comparison with the cylindrical walls.