Phenotypic analysis of null mutants for DE‐cadherin and Armadillo in Drosophila ovaries reveals distinct aspects of their functions in cell adhesion and cytoskeletal organization

Abstract

Background: DE-cadherin is an epithelial cadherin in Drosophila, and forms adherens junctions by associating with Armadillo (b-catenin). To investigate its role in oogenesis, we generated germ-line clones homozygous for a null mutation in shotgun (shg) encoding this molecule, and examined their phenotypes, comparing with those of armadillo (arm) mutants.

Ras signaling modulates activity of the ecdysone receptor EcR during cell migration in the drosophila ovary

“…Border cell phenotypes resemble mutant clones of usp and tai (Bai et al, 2000), consistent with the notion that EcR works together with these genes to modulate DE-CAD levels in migratory cells. EcR-DN leads to increased DE-CAD and precocious centripetal migration, a phenotype that appears to be opposite of the weak allelic combinations of shotgun (shg; encoding DE-CAD) that result in centripetal migration failure or inappropriate migration between nurse cellnurse cell contacts (Oda et al, 1997;Niewiadomska et al, 1999). EcR-DN dorsal appendage defects resemble usp mutant egg chambers, consistent with a common role for EcR and USP in dorsal appendage formation .…”

“…From stages 10 -14, EcR activity remains low in the dorsal appendage FC, which are associated with increased DE-CAD levels relative to the main body FC (not shown). In the egg chamber, DE-CAD is required for proper migration of the centripetal FC and border cells (Oda et al, 1997;Niewiadomska et al, 1999). Similarly, the apical accumulation of the cadherin complex component Armadillo (ARM, Riggleman et al, 1990) is increased in centripetal FC and dorsal anterior FC, which show low levels of EcR activity (Fig.…”

Hsp60C is required in follicle as well as germline cells during oogenesis in Drosophila melanogaster

“…Mutations in genes encoding cell adhesion molecules such as Armadillo, DE-cadherin, Merlin, ␣-Spectrin, etc. affect follicle cell remodeling (Oda et al, 1997;Muller, 2000;MacDougall et al, 2001;Hudson and Cooley, 2002;Steinhauer and Kalderon, 2006), and the resulting phenotypes are in several ways similar to those seen in the Hsp60C 1 mutant egg chambers. In addition to the posterior group of follicle cells, Hsp60C is also essential for generating and maintaining a patterned monolayer of all other follicle cells as evidenced by the irregular arrangement of Hsp60C 1 /Hsp60C 1 follicle cells in mitotic clones, irrespective of their location and size (Fig.…”

“…The antibodies used for immunostaining were: anti-Fas-III (1:10; Patel et al, 1987), anti-Gurken (1:30; Queenan et al, 1999), anti-Dlg (1:20;Goode and Perrimon, 1997), antiHts-RC (1:1; Robinson et al, 1994), anti-␣-spectrin (1:50;Dubreuil et al, 1987), anti-DE-Cadherin (1:20;Oda et al, 1997), all obtained from Developmental Studies Hybridoma Bank (USA); the other antibodies were Mouse monoclonal Anti-Phosphotyrosine (1:100, Santa Cruz, CA), monoclonal anti-␣-tubulin-FITC Conjugate (DM1A, 1:250, SIGMA), and rabbit polyclonal anti-Hsp60 (SPA 805, 1:100, Stressgen, Canada).…”

The Garz Sec7 domain guanine nucleotide exchange factor for Arf regulates salivary gland development in Drosophila

“…DE-cadherin has been shown to be critically important for epithelium formation and to facilitate cell migration and sorting processes that sculpt epithelial organs. 60,61 Similarly, the atypical cadherin Flamingo has been shown to have a key role in epithelial morphogenesis. [62][63][64] Based on the observed inhibition in DE-cadherin and Flamingo trafficking in Garz-depleted cells, we expected changes in salivary gland morphology.…”