Fig. 1. Epigenetic reprogramming proceeds progressively in migrating PGCs in mice. (A) H3K9me2 (red, left column) in migrating PGCs (green, middle) at E7.25, E7.75, E8.25 and E8.75 as indicated. The white bent arrow indicates a line used for the line-scan plot in C. (B) H3K27me3 (red, left column) in migrating PGCs (green, middle) at E7.25, E8.5, E8.75 and E9.5 as indicated. Images merged with Hoechst staining (blue) are shown on the right (A,B). The white bent arrow indicates a line used for the line-scan plot analysis in D. (C) Line-scan plot of relative intensity of H3K9me2 (red) and Hoechst (blue). E7.75 (top) and E8.75 (bottom) cells shown in A. (D) Line-scan plot of relative intensity of H3K27me3 (red) and Hoechst (blue). E8.75 (top) and E9.5 (bottom) cells shown in B. The areas in C and D shaded in green and pink represent PGC and somatic cell nuclei, respectively. (E) Ratio of PGCs strongly positive for H3K9me2 (top) and for H3K27me3 (bottom) during the course of development. All PGCs from each embryo were analyzed. Scale bars: 10 µm in A,B.