The Action Mechanism of Omomyc Figure 7. Omomyc influences – in an opposite way to c-Myc – the pattern of histone H3 lysine 9 acetylation and methylation, leading to decreased active and increased repressive chromatin marks. Immunofluorescence staining (in green) of ER (top), H3acK9 (middle) and H3diMeK9 (bottom panels) in parental (w.t.), Omomer, and c-Myc + Omomer expressing Rat1 fibroblasts [12] grown for 48 h with or without 4-OHT. DAPI staining (blue) was used for visualizing cell nuclei. The graphs below the immunofluorescence pictures display the quantitative PLoS ONE | www.plosone.org 10 July 2011 | Volume 6 | Issue 7 | e22284