| |
Fig. 3. Asymmetries in stomach epithelial polarity are regulated by left-right signaling. Stomach sections immunostained for α-tubulin (αtub, red) and
β-catenin (β-cat, green) in the E11.5 mouse (A-I), or Par3 (red) and E-cadherin (Ecad, green) in the stage 39 frog (J-O), reveal left-right differences in endoderm
morphogenesis. In the posterior stomach of Foxj1+/− mice, right endoderm is irregular, whereas left endoderm is more organized (D) and highly polarized,
as indicated by tight apical concentration of α-tubulin (αtub, red; arrowhead, G). Both walls of Foxj1−/− mutant embryo [Foxj1−/−(1), B,E,H], comprise polarized
cells with tight apical concentration of αtub (arrowheads, H); both sides resemble control left epithelium. In another mutant [Foxj1−/−(2), C,F,I] both sides are
irregular and resemble control right epithelium, although sub-regions exhibit greater organization and polarity (arrowhead, I). In control (DMSO) frog embryos
(J,L,N), left endoderm is more polarized than right, as indicated by enrichment of E-cadherin (Ecad; green) at apical adherens junctions (arrows, L), and
the concentration of the apical polarity marker Par3 at the lumenal surface (red; arrowheads, N). By contrast, SB505124 (K,M,O) results in right isomerism, with
left endoderm resembling right endoderm, as indicated by absence of apical enrichment of E-cadherin (M) and Par3 (O). L, left; R, right. Scale bars: 100 μmin
A-C; 50 μm in D-K; 25 μm in L-O. (See Fig. S4 for higher magnification images.) |
