Synchronization procedures

Abstract

Budding yeast is an ideal model system to study the regulatory mechanisms governing cell cycle progression. The ability to generate cell populations progressing through the cell cycle in a synchronous manner (synchronous cultures) has contributed significantly to the rapid progress in the understanding of cell cycle control in this organism. Cell populations progressing through the cell cycle in a synchronous manner are generated by arresting cells at a certain stage of the cell cycle (block) followed by removing the cell cycle block, allowing cells to resume cell division (release). Cell cycle arrests can be imposed by compounds and released from the block by removal thereof. Alternatively, cells can be arrested at a certain cell cycle stage by depleting or inactivating a gene product critical for a certain cell cycle transition and released by reactivation or resynthesis of this gene product. Finally, centrifugal elutriation can be used to obtain cells of uniform cell size. Because cell size correlates with cell cycle stage, cells obtained by centrifugal elutriation are synchronized with respect to their position in the cell cycle. This chapter discusses the advantages and disadvantages of these methods and indicates the degree of synchrony obtained with the various block-release methods.