Duplication of Spindle Plaques and Integration of the Yeast Cell Cycle

Abstract

Throughout the history of cell biology, the eukaryotic cell cycle has been subject to investigation by a wide variety of techniques. Hartwell et al. (1970) have recently introduced the use of conditional mutants to the analysis of cell-cycle events in the budding yeast Saccharomyces cerevisiae. This species is admirably suited not only to the genetic manipulation required for this approach but also to the application of molecular techniques to the characterization of its DNA (see Cryer et al., this volume; Petes et al., this volume). From the cytological view, however, the yeast cell cycle may seem superficially to lack homology with the cell cycle of higher eukaryotes. As in the basidiomycetes and other ascomycetes, yeast lacks the highly ordered centriole found in many higher eukaryotes. Furthermore, mitosis does not occur freely in the cytoplasm but proceeds within an intact nuclear envelope, the poles of the intranuclear spindles lying within the...