Study of Life-cycle of Schizosaccharomyces octosporus by means of Ultra-thin Sectioning and Electron Microscopy

Abstract

CYTOLOGICAL studies of the yeast of the genus Schizosaccharomyces have been few and limited primarily to observations by means of light microscopy^1–3. Although these studies reveal the nature of some of the general cytological changes which occur during various phases of the life-cycle of these yeasts, detailed studies are lacking. Some of the conflicting views and limited observations of these investigators may be attributed at least in part to the resolution limit of the light microscope. A study of the nature and sequence of the cytological changes which occur during cell division, conjugation, ascosporogenesis, and germination was therefore carried out by means of ultra-thin sectioning and electron microscopy in order to obtain a more detailed and accurate description of the cytological changes which occur. Various cytochemical methods were also employed in order to correlate structures observed in electron micrographs with structures observable with the light microscope. Schizosaccharomyces octosporus, N.R.R.L. Y-854, obtained from Dr. L. J. Wickerham, was selected for study. The techniques used for specimen preparation have been described previously⁴.