Fig. 3: Re-organization of anterior-posterior and dorsal-ventral axes in halved embryos.

a PCA analysis in halved embryos (triangles) and control (circles). Centroids of each stage were connected by line. b–f in situ hybridization chain reaction of intact embryos and halved embryos with foxQ2 as anterior marker and alx1 or foxA as posterior marker. b” and d”-f” show the schematic image of positional relationship between anterior and posterior region. d”, lateral view; e”, cup rim view; f”, lateral view. A-P, anterior-posterior axis. Representative images from at least three independent experiments with similar results are shown. g–i Animal pole cell was labeled with DiI (g), then the labeled cell position was observed at gastrula stage (h). Same experiment was performed with ∆cadherin mRNA injected halves (i). Percentages in (h, i) indicate the ratio of individuals whose labeled cell observed at the same position with picture [N = 8 in (h) and N = 6 in (i)]. Detail results of analysis is written in Supplementary Fig. 7. White arrowheads, position of anterior pole; White dashed line, outline of the archenteron. j–l Live-imaging of ß-catenin-Venus mRNA and membrane-TagRFP mRNA injected halves. Representative images from at least three independent experiments with similar results are shown. White dashed lines, border of animal and vegetal half; asterisks, ß-catenin positive nuclei in animal half. m, n in situ hybridization chain reaction with foxQ2 and foxA in control halved and Wnt/ßcatenin inhibited halves with C59. Percentage in (m’, n’) indicate the ratio of individuals that showed the same positional relationship between foxQ2 and foxA expression site with pictures (N = 2). o–x Gene expression patterns of nodal and lefty in intact and halved embryos. Both lateral view (q, v) and cup rim view (inserted images in q, v) were observed at cup shape. Images shown are representative of ten independent experiments performed with similar results. V-D, ventral-dorsal axis. Developmental stages are written in the upper right in each image. Bl blastula, MG mid gastrula, hpf hours post fertilization. Scale bars, 50 µm. Source data are provided as a Source Data file.