QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online September 18, 2007
doi: 10.1242/10.1242/jcs.010850

This Article Summary Full Text Full Text (PDF) Supplementary Material Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gorfinkiel, N. Articles by Arias, A. M. Search for Related Content PubMed PubMed Citation Articles by Gorfinkiel, N. Articles by Arias, A. M.

Requirements for adherens junction components in the interaction between epithelial tissues during dorsal closure in Drosophila

Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK

View larger version (115K): [in this window] [in a new window]   Fig. 1. AJ components in the AS and epidermis during DC. Stage-13 (Ai) and stage-15 (Bi) embryos stained for actin (Aii, Bii, phalloidin-TxR), E-cadherin (ECad; Aiii, Biii, green), Armadillo (Arm; Aiv, Biv, white) and -catenin (-cat; Av, Bv, green) showing the dynamic localization of these proteins at the LE (arrowheads) as DC progresses. as, amnioserosa; ep, epidermis. (C) Time-lapse images of enGal4/UAS-ECadGFP;UAS-ActinRFP embryos (supplementary material, Movies S1 and S2) showing the localization of ECad at the filopodia (arrowheads).

View larger version (102K): [in this window] [in a new window]   Fig. 2. Septate junction components and lateral markers in the AS and epidermis during DC. Stage-13 (A) and stage-15 (B) embryos stained for the basolateral marker Dlg (Aii, Bii, red) and NrxIV (Aiii, Biii, green) showing that AS cells do not show SJ proteins at the membrane. Dlg (arrowhead in Aii), but not NrxIV (arrowhead in Aiii, Biii), is present at the LE. (Ci,Di) Thick sections of a stage-13 (Ci) and stage-14 (Di) embryo stained for the basolateral marker Scrib (Cii, Dii, red), E-cadherin (ECad; Ciii, Diii, green) and FasIII or Dlg (Cvi, Dvi, white), confirming that basolateral markers (Cii, Dii, Dvi, arrowheads) are localized at the LE but that SJ-associated components (Cvi, arrowhead) are absent from the LE. (Cv, Dv) Schematic representation of the image in Ci. pAS, marginal AS cell; m, mesoderm; e, endoderm. (Ei) Stage-13 embryo expressing NrxIV with the daGal4 driver, stained for FasIII (Eii, red) and Nrx (Eiii, green). Notice the localization of Nrx at the membrane of AS cells (arrow) and at the LE (arrowheads).

View larger version (124K): [in this window] [in a new window]   Fig. 3. Roles of AJ during DC. (Ai) shgR64 embryos stained for actin (Aii, phalloidin-TxR), E-cadherin (ECad; Aiii, green), Armadillo (Arm; Aiv, white) and -catenin (-cat; Av, green). Aii-Aiv are single-channel images of the boxed area in Ai; Av is a different embryo. Note the disruption of the actin cable (Aii, arrowhead) and the reduction of ECad and Arm specially at the LE (Aiii, Aiv, arrowheads). (D) shgR64 embryo overexpressing ActinGFP in the engrailed domain. Note the presence of mismatches (arrowhead). The inset shows the filopodia formed by DME cells in these mutant embryos (arrowhead). (Bi) shgg317 embryos stained as in Ai, showing the dislodgement of the AS from the epidermis. The actin cable (Bii, arrowhead) is absent and the levels of membrane ECad (Biii, the arrowhead points at the LE), Arm (Biv), and -catenin (Bv) are very much reduced in the epidermis. (Bii, Biii) Single-channel images of the boxed area in Bi; (Biv and Bv) single-channel images from a different embryo. (E) shgg317 embryo over-expressing ActinGFP in the engrailed domain showing the dorsal hole characteristic of these embryos. The inset shows the very small filopodia formed in these mutants (arrowhead). (Ci) armYD35 embryos stained as in Ai, showing the detachment of the AS from the epidermis. In contrast to shg mutants, these embryos form an actin cable (Cii, arrowhead) and the levels of ECad (Ciii) remain high in the AS and epidermis. Arm levels are lower in both tissues (Civ) and -catenin is mainly cytoplasmic (Cv). F, armYD35 embryo overexpressing ActinGFP in the engrailed domain showing a dorsal hole. The inset shows that normal filopodia are formed in these mutant embryos (arrowhead).

View larger version (96K): [in this window] [in a new window]   Fig. 4. Rescue of the integrity of the LE. (A-C) Schematic representation of (A) full-length E-cadherin (ECad), (B) an ECad mutant protein that lacks the Arm binding domain encoded by the shgg317 allele and (C) a fusion protein where -catenin is fused to the C-terminus of full-length ECad (ECadFL–-catenin). The ability of this chimera to recruit Arm (Hii) is schematized. (D) Cuticle of shgg317 embryos showing a dorsal hole (see Table 1 for percentages of phenotypes). (E) Cuticle of a shgg317 embryo expressing ECadFL–-catenin in the engrailed domain, showing a complete rescue of the dorsal hole characteristic of shgg317 embryos. Mismatches can be observed (arrowhead). (F) Cuticle of a shgg317 embryo expressing ECadFL–-catenin in the AS, showing a complete rescue of the dorsal hole. (G-J) embryos stained for actin (phalloidin-TxR), ECad (green) and Arm (white, shown as a separate channel in Hii and Iii). (G) shgg317 embryo showing the loss of adhesion between AS and epidermis. (Hi) embryo of the same genotype as in E, showing the rescue of the adhesion between AS and epidermis. Note the elongation of DME cells. (Ii) Embryo of the same genotype as in F, showing that the expression of ECadFL–-catenin in the AS rescues the adhesion between the AS and the epidermis. (J) shgg317 embryo expressing a wild-type form of ECad fused to GFP (UAS-ECadGFP) in the engrailed domain, showing local rescue of the adhesion between the AS and the epidermis.

View larger version (58K): [in this window] [in a new window]   Fig. 5. Interactions between E-cadherin (ECad) and Arm are required during DC. (A) Schematic representation of a fusion protein, in whih -catenin is fused to a form of ECad that lacks the Armadillo (Arm)-binding domain (ECad–-catenin) and thus is not able to recruit Arm (Cii). (B) Cuticle of a shgg317 embryo expressing ECad–-catenin in the engrailed domain showing the lack of rescue of the dorsal open phenotype. (Ci) Embryo of the same genotype as in B, stained for actin (phalloidin-TxR), ECad (green) and Arm (blue, shown as a separate channel in Cii. Notice the lack of recruitment of Arm in the engrailed stripes) showing that the expression of the ECad–-catenin is not able to rescue the adhesion between the AS and the epidermis. (D) Schematic representation of the ECadFL–-catenin chimera in an Arm-mutant background. (E) Cuticle of an armYD35 embryo showing the dorsal open phenotype. (F) Cuticle of an armYD35 embryo expressing ECadFL–-catenin in the engrailed domain. No rescue of the dorsal hole is observed. (G) Embryo of the same genotype as in E, stained for actin (phalloidin-Txr) and ECad (blue). No rescue of the adhesion between the AS and the epidermis is observed (arrowhead).