Real-time imaging of meiotic chromosomes in Saccharomyces cerevisiae.

Important information on cellular physiology can be obtained by directly observing living cells. The nucleus, and the chromatin within, is of particular interest to many researchers. Monitoring the behavior of specific DNA loci in the living cell is now commonly achieved through the insertion of binding sites for fluorescently tagged proteins at the sequence of interest (e.g. Ref 1). However, visualizing the behavior of full length chromosomes can only be achieved when they constitute discrete, relatively well individualized units. During meiotic mid-prophase, chromosomes of budding yeast are well-organized structures that present such characteristics, making them remarkably suited for visualization. Here we describe the optimized protocols and techniques that allow monitoring of chromosome behavior during meiotic prophase in budding yeast.