Analysis of Cellular Adhesion in Cultured Cells

Many cell adhesion molecules have been identified and characterized from Drosophila. This chapter describes a cell culture assay that adds a new tool for the analysis of cellular adhesion in Drosophila. Cell adhesion interactions can be classified as either hemophilic—that is, an adhesive interaction between two molecules of the same species, or heterophilic—that is, an interaction between different protein species. The chapter discusses the procedures developed for the analysis of cellular adhesion in cultured Drosophila cells. The procedures are described as if homophilic adhesion molecules are being assayed. The assays for heterophilic interactions require separate cell lines expressing both molecular components of the interaction. A distinction should be drawn between cell adhesion and the possible secondary effects of cell adhesion. Cell adhesion is a simple strengthening of the physical association between two cells. Some studies suggest that the binding of cell adhesion molecules may be accompanied by the generation of intracellular signals that can initiate changes in the participant cells.