Fig. 2: cDNA library screening.

a Experimental scheme depicting the four screening conditions. b Flow cytometry analysis of EOS-tagBFP and DPPA2-mKO2 expression in 27 NaiveRep_KF cell lines. c Genomic PCR analysis showing proviral integrations in the 27 NaiveRep_KF cell lines. d Flow cytometry analysis of EOS-tagBFP and DPPA2-mKO2 expression in 14 NaiveRep_FCS + LIF cell lines. e Flow cytometry analysis of EOS-tagBFP and DPPA2-mKO2 expression in 3 NaiveRep_KOSR + LIF cell lines. f Genomic PCR analysis identifying the cDNAs integrated in the 14 NaiveRep_FCS + LIF cell lines and 3 NaiveRep_KOSR + LIF cell lines. g Flow cytometry analysis of EOS-tagBFP and DPPA2-mKO2 expression in 32 NaiveRep_VALGöX cell lines. h Genomic PCR analysis identifying cDNAs in 21 of the 32 NaiveRep_VALGöX cell lines. i Immunostaining for H2AK119Ub and H3K27me3 in four NaiveRep_VALGöX cell lines (from two independent experiments). Scale bars: 20 µm. j Histograms showing the percentage of cells with H2AK119Ub and H3K27me3 nuclear foci in four NaiveRep_VALGöX cell lines and in NaiveRep_VAL control cells. All cells were quantified individually (exact n indicated) from two independent experiments, except for H2AK119Ub analysis in lines #16 and # 25, which were analyzed in three independent experiments. Each dot represents the mean percentage of cells with nuclear foci per replicate; error bars indicate mean ± SEM. Statistical comparisons to NaiveRep_VAL controls were performed using a two-sided Welch’s t-test for unequal variances. For H2AK119Ub, a reduced percentage of cells with nuclear foci was observed in all NaiveRep_VALGöX cell lines (#1, #14, #16, and #25; p = 0.17, 0.01, 0.00006, and 0.00003, respectively). For H3K27me3, Line #1 was not significantly different from controls (p = 0.30), while lines #14, #16, and #25 showed reduced percentage of cells with nuclear foci (p = 0.09, 0.001, and 0.002, respectively). Source data are provided in the Source Data file.