The α-Cat M region supports the enrichment of Cno at TCJs. (A) Stills of lateral ectoderm at stage 8 of α-Cat-RNAi α-CatX live embryos expressing Cno::YFP. In close-ups at right, orange arrowheads point to TCJs and FI displayed as in color map; maximum FI (4,095), white. Scale bar, 10 μm. (B) Cortical levels of Cno FI in α-Cat-RNAi α-CatX embryos. (C) Levels of Cno measured at intact TCJs in α-Cat-RNAi α-CatX embryos. For B and C, significance is determined by Kruskal–Wallis test with Dunn’s multiple comparisons test; bold line, median; dotted lines, interquartile ranges; and n = a pooled number of cells (c) or vertices (v) for a number of embryos (e). (D) Ratio of the mean FI Cno at TCJs vs. BCJs is plotted per embryo. Significance is given by ordinary one-way ANOVA with Tukey’s multiple comparisons test. (E) Ratio of mean Cno FI in horizontal and vertical BCJs and TCJs per embryo. Significance determined by ordinary two-way ANOVA with Tukey’s multiple comparisons test. (F–H) Ratio of mean FI of Cno (F), Jub (G), and Ecad (H) at vertices joining three, four, or five cell junctions as compared to mean FI at BCJs within the same embryo (schematic at right; red arrows indicate contractile actomyosin). For plots in D–H, bar height represents mean, error bars represent SD, and n = number of embryos analyzed (e). For E–H, significance determined by ordinary two-way ANOVA with Tukey’s multiple comparisons test. Comparisons between vertices linking three, four, and five junctions performed as pairwise within embryos by using two-way ANOVA as a mixed effects model with Geisser-Greenhouse correction and Tukey’s multiple comparisons test (**** = P < 0.0001, *** = P < 0.001, ** = P < 0.01, * = P < 0.05). (I) Schematic summary: While Cno is recruited to BCJs through an alternate pathway, M2/3 supports the enrichment of a pool of Cno at vertices, as well as enrichment of Jub and Ecad.