Improving our understanding of the mechanisms that govern cell motility and invasion is crucial for understanding development and how these processes go awry in metastasis. Border cell migration during Drosophila oogenesis is a well-studied model of invasive and directed migration, which has now been analysed by Abdelilah-Seyfried et al. in flies mutant for bazooka andDaPKC (components of an epithelial polarity- and adhesion-regulating complex) and for the tumour suppressor genes, dlg1 and lgl. Their findings on show that the aberrant invasion of germ cells by dlg1- follicle epithelial cells surprisingly requires wild-type Bazooka function, possibly because Bazooka stabilizes adhesion between the invading somatic cells and their germ-cell substratum. By contrast, Bazooka function is dispensable for border cell invasion and motility, perhaps because it mediates cell adhesion within the migrating border cell cluster. These findings reveal distinct functions for Bazooka during different types of epithelial cell invasion.
