The effect of dAda2b transgenes on histone acetylation. A: Immunostaining of polytene chromosomes of wild type (w1118), dAda2b null (dAda2bd842), and dAda2b transgene-carriers (null mutant for endogenous dAda2b) with anti-histone H3K9ac and H3K14ac antibodies. Images of the same polytene chromosomes stained with a Pol II large subunit specific antibody 7G5 are shown as staining controls. Genotypes are indicated on the top. Transgenes carrying EGFP-fused dADA2b isoform were expressed from the native dAda2b promoter, while the expression of UAS-dAda2bS transgene was driven by da-GAL4 driver, as indicated. Primary antibodies were as indicated on the left. B: Comparison of histone H3K9ac and histone H3 levels in larval extracts of the same genotypes shown in A. The same filter used for detection of H3K9ac was re-probed with H3- specific antibodies.