Figure 1. Planar polarized localization of Prickle2 and Vangl2 in the neural plate.

(A) Neural epithelium mosaically labeled with GFP-Vangl2, RFP-Pk2, and membraneBFP showing the overlapping localizations of Pk2 and Vangl2. Anterior is up, and scale = 10 µm. (B) Graph plotting GFP-Pk2 intensity along V-junctions (0–45° relative to mediolateral axis) and T-junctions (46–90° relative to mediolateral axis) normalized as a ratio to the mean cytoplasmic intensity in control cells and cells expressing Xdd1 and Pk2-ΔPΔL. Error bars represent standard deviation. Ctrl V vs. T, p<0.0001***; Xdd1 V vs. T, p=0.5799; Pk2-ΔPΔL V vs. T, p=0.173; Ctrl V vs. Xdd1 T, p=0.5770; Ctrl T vs. Pk2-ΔPΔL V, p=0.0268 (Mann Whitney test for significance). n = 101 V and 71 T from three experiments, seven embryos (Ctrl); n = n = 171 V and 199 T from four experiments, five embryos (Xdd1); n = 128 V and 142 T from three experiments, seven embryos (Pk2-ΔPΔL). (C) Distributions of data shown in (B) plotted against the angle of the junction at which the intensity was measured. Correlation coefficients for Xdd1 and Pk2-ΔPΔL were significantly different from controls using the Fischer R-to-Z transformation. n = 172 junctions (Control), n = 263 junctions (Xdd1) and n = 245 junctions (Pk2-ΔPΔL) (D-E) Confocal images of Xenopus neural epithelia labeled evenly with GFP-Pk2 and membraneBFP and mosaically with H2B-RFP, serving as a tracer for either Xdd1 (C) or Pk2-ΔPΔL (D) expression. Scale = 10 µm.

Figure 1—figure supplement 1. GFP-Pk2 localizes to anterior apicolateral regions of cells in the Xenopus neural plate.

Pseudo 3D render of neural epithelium mosaically labeled with GFP-Pk2 and membraneRFP showing Pk2 restricted to the apicolateral anterior regions.

Figure 1—figure supplement 2. Pk2 knockdown results in embryonic convergent extension phenotypes.

(A) Dorsal view: stereoscope images of a representative Stage 20 control embryo, an embryo that has been injected dorsally with 25 ng Pk2 morpholino, an embryo that received morpholino plus a 400 pg GFP-Pk2 mRNA rescue dose, and an embryo that received only the 400 pg Pk2 mRNA. Anterior is up. (B) Graph of the distance between the neural folds at stage 20. n = 8 (Control), 14 (Pk2 KD), 8 (Rescue), 9 (RNA/OE). Control vs. KD, p<0.0001; vs. Rescue, p=0.0019; vs. OE, p=0.0079. (Mann-Whitney Test for significance). Error bars represent standard deviation. (C) Images of Dorsal marginal zone (DMZ) explants dissected from stage 11.5 embryos of the treated under the same conditions as in (A). (D) Graph of DMZ explant length at a time when embryos that had not been dissected had reached Stage 20. n = 19 (Control), 19 (Pk2 KD), 16 (Rescue), 4 (RNA/OE). Control vs. KD, p<0.0001; vs. Rescue, p=0.0010; vs. OE, p=0.0041. (Mann-Whitney Test for significance). Error bars represent standard deviation. (E) Representative images of Stage 30 embryos that received 30 ng Pk2 morpholino, morpholino plus 400 pg rescue GFP-Pk2 mRNA, or controls that received neither. Anterior is left and dorsal is up. (F) Graph of the length of the dorsal embryonic length of embryos represented by those shown in (E). n = 35 (Control), n = 37 (Pk2 KD), n = 44 (Rescue). Control vs. KD, p<0.0001; vs. Rescue, p<0.0001. (Mann-Whitney Test for significance). Error bars represent standard deviation.

Figure 1—figure supplement 3. A dominant negative Pk2 disrupts convergent extension.

(A–B) Stereo images of a stage 30 control embryo (A) and clutchmate dorsally expressing Pk2-ΔPΔL (B) which failed to properly extend the body axis.