Rab11 determines the localization and assembly of AJs. (A-F) The distribution of β-catenin in WT (A), rab11a (B), rab11ba (C), rab11a/rab11ba dKO (D), eGFP-2A-Rab11a overexpressed (E) and eGFP-2A-Rab11a S25N overexpressed (F) embryos at 36 hpf. a (anterior) and p (posterior) in A show the lens orientation. Arrows (E,F) show that eGFP-2A-Rab11a S25N, but not eGFP-2A-Rab11a, impeded the apical enrichment of β-catenin. (G) Scheme showing locations of apical and basal spots for relative fluorescence intensity measurements. (H) Quantification of apical/basal relative intensity of β-catenin shown in A-F (n=20 lenses from 10 embryos). (I,J) Both dKO of rab11a/rab11ba (I) and overexpression of Rab11a S25N (J) disrupted the AJs_EE zonula adherens at 36 hpf. Arrow shows AJs_EF punctum adherens. a (apical) and b (basal) show the orientation of lens epithelial cells. (K) Overexpression of Rab11a S25N or rab11a/rab11ba dKO significantly impeded the formation of AJs_EE. The number of AJs_EF also significantly decreased in rab11a/rab11ba dKO mutants (n=56 epithelial cells for rab11a/rab11ba dKO mutants, and 73 for Rab11a S25N overexpressed embryos). (L) The length of AJs_EE in Rab11a S25N overexpressed or rab11a/rab11ba dKO mutant lens (0.19±0.02 μm) was comparable with that in nok mutants and significantly shorter than that in WT. (M) Although the number of LJs_EE significantly increased in Rab11a S25N overexpressed or rab11a/rab11ba dKO mutant lens (0.15±0.01 μm), the length of LJs_EE was comparable with that in WT and nok mutants. Ep, epithelium; FC, fiber cells. Scale bars: 10 μm (A-F), 400 nm (I,J). *P<0.05, **P<0.01, ***P<0.001, n.s>0.05.
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