Preparation of the Fission Yeast Schizosaccharomyces pombe for Ultrastructural and Immunocytochemical Study

The fission yeast Schizosaccharomyces pombe serves as a model system for investigating a wide variety of problems in eukaryotic cellular and molecular biology. Although probably most widely studied in relation to the control of the eukaryotic cell cycle (1 ) and the events of cell division (2 ,3 ), S. pombe has also received significant attention in studies of protein trafficking and secretion (4 ), cell wall biosynthesis (5 ), cellular and molecular aspects of meiosis, genetic recombination, and spore formation (6 ), signal transduction pathways and control of gene expression (7 -10 ) and cell growth (11 ,12 ), cell morphology (13 ,14 ) and the cytoskeleton (15 ,16 ). In many ways we can think of S. pombe as essentially a typical eukaryote trapped inside a cell wall, and the resulting constraints on cell morphology confer on it a stereotyped cellular architecture, well suited to ultrastructural analysis. The details of this architecture at both the light- and electron-microscopic level can be found in reference (17 ); here we will only highlight certain features.