Loss of fra results in Rho1-mediated basement membrane degradation and invasion. GFP expression marks mutant cells in B,C,D,E, and mutant cells are marked by lack of GFP expression in A. The basement membrane (marked by Perlecan staining, red in all panels) is degraded in regions where fra3mutant clones (circled GFP-negative clone, A; nuclear stain is shown in blue) or P35-rescued fra4mutant clones (green, C) are generated (compare to green control clones expressing P35 alone which do not disrupt the basement membrane in B). fra3(A) and P35-rescued fra4mutant cells (C) invade the basement membrane (compare to control in B). Neither invasion nor degradation of the basement membrane is blocked by coexpression of dominant negative-JNK in fra4mutant cells (green, D). Coexpression of DN-Rho1 in fra4mutant clone cells (green, E) partially rescues basement membrane degradation and cell invasion. Clones were generated with the eyFLP driver in all panels except B, in which clones were generated with hsFLP. Orthogonal sections through the posterior dorsal edge of eye discs are oriented apical up in all panels.