EKLF knockdown increases RNA polymerase II occupancy and acetylation of histone H3 at the Gp1b and GpIIIa megakaryocytic gene promoters. 4D7 cells were treated for 2 days with (■) or without doxycycline (□) to knock down EKLF followed by 2 days in presence of HMBA to induce their differentiation as described in Figure 1. Chromatin immunoprecipitation analyses were then performed using either control anti-HA antibody or specific antibodies directed against RNA-polymerase II (A) or acetylated histone H3 (B). Immunoprecipitated DNA was quantified by real-time PCR using specific primers corresponding to the promoters or an internal position of GpIX and Gp1b megakaryocytic genes as well as to the silent myoD gene. Results are expressed as relative proportions of immunoprecipitated DNA (ratios of immunoprecipitated versus input DNA) standardized to the ratio obtained for the GpIX promoter in untreated cells (means and standard deviations from 3 independent cultures). Significant (P < .05; paired Student test) doxycycline effects are indicated by asterisks.