Loss of dcortactin or cindr rescues dmim border cell migration defects. (A) GST cosedimentation assay using candidate GST proteins and S2 cell-derived DMIM protein. DMIM binds to itself, human MIM, and DCortactin. (B) Immunoprecipitation assay using an antibody to endogenous DCortactin and lysates from Myc-tagged DMIM constructs. FL (full length DMIM); ΔI-BAR (lacking the IBAR domain); ΔPRD (lacking the polyproline-rich domain). (C) MIM or Cortactin knockdown alters EGF-induced directional cell migration. Transwell migration assays showing alterations in the migration of ptc^−/− MEFs through a permeable membrane in response to an EGF or PDGF gradient over the course of 8 h. Data are represented as the mean ± SEM from three separate experiments (*, P < 0.01; **, P < 0.001; t test). (D) Schematic of a stage 10 egg chamber and scale used to score border cell migration defects. Anterior is to the left. (E) Confocal immunofluorescence images of egg chambers from wild-type, dmim, dcortactin, dmim; dcortactin, cindr RNAi, and dmim/cindr RNAi double-mutant egg chambers stained with phalloidin (F-actin, red). White arrowheads indicate the border cell cluster. Bar = 50 µm. (F and H) Quantification of stage 10 border cell migration for the indicated genotypes; more than 100 egg chambers were examined per genotype. (G and I) Quantification of the amount of FM4-64 dye uptake over time for each indicated genotype. Data are represented as the mean ± SEM from three separate time series for each genotype. Knockdown of dmim in combination with either dcortactin or cindr is able to partially rescue the increase in dye uptake seen in the dmim mutant border cells.