Chromosome spreading and immunofluorescence methods in Saccharomyes cerevisiae.

Visualization of meiotic chromosomes in the model organism S. cerevisiae has become an integral part of the study of wild-type meiosis and the characterization of mutant phenotypes. This chapter describes a simple method for chromosome spreading, which is a variation on a protocol originally developed by Dresser and Giroux. This method uses osmotic pressure to spread the nuclear contents of spheroplasted meiotic cells over a glass slide enabling unobstructed inspection of the chromosomal morphology. Chromosomes from all meiotic stages can be analyzed using indirect immunofluorescence to visualize meiotic proteins involved in different processes of meiosis, including recombination, synapsis, sister chromatid cohesion, and chromosome disjunction.