| Abstract: | A correlation has been found between histone acetylation and gene activation at the time of gastrulation in the sea urchin, Arbacia punctulata. Between the blastula and gastrula stages, there is a 2.5-fold increase in the rate of acetylation of a histone fraction consisting of slightly lysine-rich and argininerich components, with a marked decrease in the fully differentiated pluteus stage. This pre-gastrular increase in histone acetylation is not correlated with (1) a decrease in the rate of histone deacetylation; (2) a decrease in acetyl coenzyme A pool size; (3) an increase in acetate uptake; (4) histone synthesis. The results thus suggest that increased histone acetylation may be at least one preparative factor for the activation of new genes at gastrulation. |
