Fig. 3: ASPP2^EpiΔE4/ΔE4 and ASPP2^RAKA/RAKA embryos phenocopy ASPP2^ΔE4/ΔE4 embryos.

a The expression of ASPP2 was conditionally ablated in the epiblast to test for its epiblast-specific requirement (ASPP2^EpiΔE4/ΔE4 embryos). The ASPP2 expression pattern was analysed by indirect immunofluorescence in ASPP2^EpiWT/ΔE4 (representative images from four embryos) and ASPP2^EpiΔE4/ΔE4 (representative images from four embryos) embryos. ASPP2 proteins were completely absent at the apical junction of epiblast cells in ASPP2^EpiΔE4/ΔE4 embryos. Note that the ASPP2 antibody results in a nonspecific nuclear signal (also seen in Fig. 1c when depleting ASPP2 by siRNA). The dashed area highlights the ectopic accumulation of cells in the epiblast. b Immunofluorescence of wild type (representative images from seven embryos) and ASPP2^RAKA/RAKA (representative images from three embryos) E6.5 embryos using an anti-Par6 antibody. The green dashed line highlights the ectopic accumulation of cells in the epiblast of ASPP2^RAKA/RAKA embryos. c Magnification of the corresponding dashed regions in b. Note the reduced amount of Par6 along the apical domain of epiblast cells in ASPP2^RAKA/RAKA embryos (orange arrowhead). Nuclei and the F-actin cytoskeleton were visualised with DAPI and Phalloidin, respectively. Scale bars: 20 μm.