(A) Western blotting for the indicated proteins performed 48 hours after adenoviral transduction in primary IMCs isolated from 1-week-old Hdac3fl/fl;Cre− pups, plated in micromass cultures, and transduced with Ad-GFP or Ad-Cre on day 3 of culture. (B) Micromasses described in (A) were fixed 48 hours after adenoviral transduction and stained with Alcian blue. (C and D) qPCR to validate RNA-seq results from Hdac3-depleted IMCs described in (A). Differential expression of representative genes with decreased (C) or increased (D) expression in HDAC3-deficient micromasses (Ad-Cre) is shown relative to control (Ad-GFP) IMCs, which was set to 1 (n = 3). (E to I) ChIP-seq was performed for H3K27ac in HDAC3-deficient micromasses described in (A). Average binding profiles of H3K27ac 5 kb upstream or downstream of the transcriptional start site (TSS) in control (blue) or HDAC3-deficient (green) micromasses: all genes (E), genes with increased expression after Hdac3 depletion (F), and genes with decreased expression after Hdac3 depletion (H). Representative distribution of H3K27ac in select genes with corresponding increased (G) or decreased (I) expression. *P = 0.05, Student’s t test.