Figure 4.

Effect of feeding PBA on acetylation of histones H3 and H4. w¹¹¹⁸ flies were raised for 10 days at 29°C on medium containing various concentrations of PBA. Histones prepared from whole flies were probed on Western blots with antibodies specific for acetylated or nonacetylated forms of the tails of histones H3 and H4. Ten micrograms of histone were used per lane. In flies treated with PBA, the acetylated forms of both H3 and H4 were increased, whereas the nonacetylated forms decreased. (a) Histone H3 in w¹¹¹⁸ flies. Abundance of the acetylated form increases with concentration of PBA added to the food. The nonacetylated form decreases (mixed males and virgin females). (b) Similar result for histone H4 in w¹¹¹⁸ flies (mixed males and virgin females). (c) w¹¹¹⁸ males and virgin females assayed separately. The effect of PBA is similar in both sexes. (d) Increase of acetylation of histone H3 in wild-type strain Canton-S (mixed males and virgin females).