Figure 4.

Evaluation of RA responsive DNA element on Zscan4 promoter. (A) Flow cytometry analysis of ESC^Zscan4_GFP lines expressing GFP under Zscan4 promoter regions of: S_288 (short), ML_480 (Mid-length) and L_2400 (Long) starting from Transcription Start Site (TSS). ESC^Zscan4_GFP lines were cultured for 5 days in media with or without RA. (B) Schematic representation of genetic constructs of ML_480 Zscan4 promoter that contains either wild type Dux Binding Motif (DBM^WT) or mutant (DBM^mut) at about −330 bp from the transcription start site (TSS) (left). ESCs^DBM−WT and ESCs^DBM−mut were cultured in RA for 5 days, and the percentage of Zscan4⁺ cells were analyzed by cytofluorimetry assay. The average and SEM of three independent biological experiments are shown: *p < 0.05, **p < 0.01 in a Student's t-test.