FIGURE 3. Separation and analysis of PGCs undergoing distinct phases of the reprogramming process.

a, Transient appearance of two populations of GFP-expressing PGCs at E11.5. The x and y axis represent the FSC (forward scatter) and GFP intensity values, respectively. The lower panels show the profiles of the GFP (germ-cell specific) signal. Note the appearance of two distinct peaks at E11.5. b, Separation and analysis of the chromatin configuration of the two populations of PGCs, denoted A and B, at E11.5. Population B is more advanced and shows loss of histone H1 and H2A.Z. Top images, population A; bottom images, population B. Note the cytoplasmic localization of CAF-1 in these populations and the relocalization of NAP-1 from the cytoplasm to the nucleus in population B (for details see the text). Cells shown here are representative of the populations. Between 50 and 100 PGCs were examined for each population. Scale bar, 10 m. c, Analysis of DNA methylation of Peg3 and lit1 (Kcnqtot1) DMRs in distinct populations of E11.5 PGCs using bisulphite genomic sequencing. Each line represents an independent clone. Open and closed circles represent non-methylated and methylated CpGs, respectively. The numbers represent the number of sequenced clones with identical methylation profile.