G9a is bound at MERVL and H3K9me2 enrichment at MERVL elements is dependent on G9a. (A-B) ChIP and qPCR of G9a in TT2 wt and G9a KO mESCs at LTR of MERVL and MERVL internal region and LTRs of IAPEz and MMERVK10C. IgG, negative control IP. Data are mean enrichment from three technical replicates as a percentage of the input chromatin and error bars represent SD. (C-E) N-ChIP and qPCR was performed for H3K9me1 (me1), H3K9me2 (me2), H3K9me3 (me3) and IgG as a negative control in TT2 wt and G9a KO mESCs at the LTRs of MERVL, IAPEz and MMERVK10C. Data are mean enrichment (+/-SD) for three technical replicates normalized to input. IgG, immunoglobulin G; IP, immunoprecipitation; SD, standard deviation.