SDS polyacrylamide gel electrophoresis of chromatin proteins from yeast during vegetative growth and sporulation

Abstract

Chromatin was isolated from yeast during vegetative growth and sporulation by differential centrifugation after breaking the cells with glass beads. The preparations were analysed by SDS polyacrylamide gel electrophoresis. Three prominent stained polypeptide bands, molecular weights 51,000, 49,000 and 48,000 were observed in chromatin from a sporulating culture with the majority of cells in meiotic prophase. The bands were absent or very faint in chromatin from cells growing exponentially in glucose medium and from stationary cells. The 51,000 molecular weight band was also found in chromatin from cells growing exponentially in acetate growth medium. The 49,000 and 48,000 polypeptides can be extracted from chromatin with 0.25m-hydrochloric acid and with 0.6m-sodium chloride. They seem to increase in concentration between 0 and 6 hours in sporulation medium, and were found with similar intensities in chromatin from sporulating and non-sporulating diploids in sporulation medium. No other polypeptide differences in chromatin between sporulating and non-sporulating cells were observed.