Muscle development involves a series of morphogenetic events including cell fusion, migration and epidermal attachment. At various points in this complex developmental program, regulation of muscle-muscle and muscle-epidermal adhesion is crucial. One of the best-characterised adhesion events is the formation of stable, integrin-based adhesions at the attachment sites formed between the ends of muscles and epidermal cells, but other adhesion mechanisms are involved in earlier stages. Here we review recent work from Drosophila on the role of adhesion during muscle development, situating integrin function within the wider developmental program.

Table 1 | A selection of key experimental methods for construction of cell atlases at different levels of biological organization 1. Clinical data Clinical-trial data; health records; disease registries; patient registries Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Vinculin is a highly conserved protein involved in cell adhesion and mechanotransduction, and both gain and loss of its activity causes defective cell behaviour. Here, we examine how altering vinculin activity perturbs integrin function within the context of Drosophila development. Whereas loss of vinculin produced relatively minor phenotypes, gain of vinculin activity, through a loss of head–tail autoinhibition, caused lethality. The minimal domain capable of inducing lethality is the talin-binding D1 domain, and this appears to require talin-binding activity, as lethality was suppressed by competition with single vinculin-binding sites from talin. Activated Drosophila vinculin triggered the formation of cytoplasmic adhesion complexes through the rod of talin, but independently of integrin. These complexes contain a subset of adhesion proteins but no longer link the membrane to actin. The negative effects of hyperactive vinculin were segregated into morphogenetic defects caused by its whole head domain and lethality caused by its D1 domain. These findings demonstrate the crucial importance of the tight control of the activity of vinculin.