Histone acetylation in differentiating chick myoblast cultures

Histone acetyltransferase activity in cell extracts from chick myoblast cultures increases up to 24h of cell culture and then decreases steadily to about 30-40% of the 24h value after 6 to 7 days. The decrease in specific activity is independent of the initial cell density. Histone acetylation in intact cells has also been studied by tritiated-acetate labelling. Most of the radioactivity is found in histones H2b, H3 and H4 when separated on acid-urea gels, and is not prevented by puromycin.