ADHERENS JUNCTIONS IN THE DROSOPHILA EMBRYO - THE ROLE OF E-CADHERIN IN THEIR ESTABLISHMENT AND MORPHOGENETIC FUNCTION

The integrity of epithelia depends largely on specialised adhesive str uctures, the adherens junctions. Several of the components required fo r building these structures are highly conserved between vertebrates a nd insects (e.g. E-cadherin and alpha- and beta-catenin), while others have so far been found only in invertebrates (e.g. crumbs). Two recen t papers((1,2)) show that the Drosophila E-cadherin is encoded by the gene shotgun. Phenotypic analyses of shotgun as well as armadillo (bet a-catenin) and crumbs mutants provide new insights into the mechanisms by which adherens junctions are built and, further, show that the req uirement for E-cadherin largely depends on the morphogenetic activity of an epithelium.