Knockdown of factors in the repressive Atf7ip module that link the DNA methylation and H3K9methylation pathways also reactivates Xi-reporters. (A) Female Xi-luciferase reporter MEFs (XiCAG-LuciferaseXaΔXist MEFs) were treated indicated siRNAs and combinations thereof in the presence of 0.2 uM 5-aza-2’-dC, and luciferase activity was measured 72 h later. The Graph depicts the measured raw ALU values and error bars indicate the standard deviation of values from three individual wells with the same treatment in one experiment. * = P <0.05 relative to siControl (siGFP) by Student’s T-test. (B) As in (A), except that the 5-aza-2’-dC treatment was omitted. (C) As in (A), but Xi-luciferase reporter MEFs were treated with siRNAs targeting various regulators of H3K9methylation, without concomitant inhibition of DNA methylation (untreated), in the presence of 0.2 uM 5-aza-2’-dC, or with depletion of Dnmt1 (siDnmt1), and luciferase activity was measured 72 h later.