Fig. 7. RhoC and ROCK are involved in epiblast differentiation. (A) Results of DNA microarray analysis reveals that Rac1 and Cdc42 are expressed throughout EB differentiation and may not be dependent on FGF signalling. However, expression of RhoC is higher in the wild type than in the dnFgfr mutant and has its maximum at day 4, when epiblast differentiation is at its peak. (B-F) Transcription electronmicroscopy. (B-D) Wild type. (B) Overview; (C) adhesion structure in endoderm; (D) adhesion structure in the epiblast. (E,F) Y-27632 treatment of wild type. (E) Overview; (F) adhesion structure in endoderm. Abbreviations: end, endoderm; ect, ectoderm or epiblast. Scale bars: in E, 10 µm for B,E; in F, 0.5 µm for C,D,F. Arrows in C,D,F indicate adhesion structures. White square in B indicates the position of the adhesion structure in D.