E-cadherin is required for gastrulation cell movements in zebrafish

Abstract

E-cadherin is a member of the classical cadherin family and is known to be involved in cell-cell adhesion and the adhesion-dependent morphogenesis of various tissues. We isolated a zebrafish mutant (cdh1(rk3)) that has a mutation in the e-cadherin/cdh1 gene. The mutation rk3 is a hypomorphic allele, and the homozygous mutant embryos displayed variable phenotypes in gastrulation and tissue morphogenesis. The most severely affected embryos displayed epiboly delay, decreased convergence and extension movements, and the dissociation of cells from the embryos, resulting in early embryonic lethality. The less severely affected embryos survived through the pharyngula stage and showed flattened anterior neural tissue, abnormal positioning and morphology of the hatching gland, scattered trigeminal ganglia, and aberrant axon bundles from the trigeminal ganglia. Maternal-zygotic cdh1(rk3) embryos displayed epiboly arrest during gastrulation, in which the enveloping layer (EVL) and the yolk syncytial layer but not the deep cells (DC) completed epiboly. A similar phenotype was observed in embryos that received antisense morpholino oligonucleotides (cdh1MO) against E-cadherin, and in zebrafish epiboly mutants. Complementation analysis with the zebrafish epiboly mutant weg suggested that cdh1(rk3) is allelic to half baked/weg. Immunohistochemistry with an anti-beta-catenin antibody and electron microscopy revealed that adhesion between the DCs and the EVL was mostly disrupted but the adhesion between DCs was relatively unaffected in the MZcdh1(rk3) mutant and cdh1 morphant embryos. These data suggest that E-cadherin-mediated cell adhesion between the DC and EVL plays a role in the epiboly movement in zebrafish.

Cadherins in development: cell adhesion, sorting, and tissue morphogenesis

“…When E-cadherin adhesion is disrupted during Zebrafish epiboly, epiblasts still intercalate but are not stabilized in the external layer and often deintercalate (Kane et al 2005;Shimizu et al 2005). Intercalation during gastrulation involves remodeling of AJs to expand cell-cell adhesions in one plane of the epithelium and contract them in the perpendicular plane (Bertet et al 2004).…”

Quantitative differences in tissue surface tension influence zebrafish germ layer positioning

“…These studies showed that merely changing the expression level of a single adhesion system can result in markedly altered sorting behavior (Duguay et al, 2003;Foty and Steinberg, 2005). In zebrafish E-cadherin mutant and morphant embryos, mesendodermal germ layer morphogenesis is initially largely unaffected (Babb and Marrs, 2004;Kane et al, 2005;Montero et al, 2005;Shimizu et al, 2005), indicating that E-cadherin activity is not critical for mesendodermal progenitor cell ingression and early migration. The key difference between our in vitro experiments and the situation in E-cadherin mutant and morphant embryos is that we specifically down-regulated E-cadherin expression in one of the two germ layer tissues, whereas in the mutant and morphant embryos E-cadherin expression of both germ layers was equally affected.…”

Cadherin 6B induces BMP signaling and de-epithelialization during the epithelial mesenchymal transition of the neural crest

“…The roles of cadherins in morphogenetic processes that entail enhanced cell motility are much more varied and complex, and can mediate dynamic behaviors of cells as well as stable interactions (Brieher and Gumbiner, 1994;Chihara et al, 2003;Geisbrecht and Montell, 2002;Matsunaga et al, 1988;Medioni et al, 2008;Pollack et al, 1998;Shimizu et al, 2005). Moreover, a loss of the expression of one cadherin during an EMT or similar morphogenetic process is often associated with the increased expression of a different cadherin.…”