dmim-null flies display abnormal cell migration. (A) Immunohistochemistry of Drosophila embryos at different developmental stages stained with anti-VASA antibody to highlight the progress of germ cell migration. dmim mutants display retained germ cells outside of the embryo at stage 9 and mislocalized germ cells in the mesoderm at stage 15. Red arrowheads indicate the position of the primordial germ cells throughout each stage. Bar = 50 µm. (B) Quantification of germ cell migration from two different developmental stages where dmim mutants display an aberrant migration pattern. (C) dmim mutants are delayed in migration of the border cells in stage 10 egg chambers. The egg chambers are stained with phalloidin (F-actin, red). Bar = 50 µm. (D) Expression of a UAS-DMIM-Myc transgene under the 306-Gal4 driver shows expression of the construct in the border cells in both the dmim mutant and wild-type backgrounds. White arrowheads indicate the border cell cluster. Bar = 50 µm. (E) Quantification of border cell migration using the scale described in F; more than 100 egg chambers were examined per genotype. (F) Schematic of a stage 10 egg chamber and scale used to score border cell migration defects. Anterior is to the left. (G) Border cell stained for pTyr (green) and F-actin (red) indicating the portion of the cell membrane where active signaling is occurring. Bar = 5 µm. (H) Quantification of the ratio of posterior to anterior pixel staining with the pTyr antibody. Initial polarized pTyr has been shown to be crucial for proper border cell migration (Jékely et al., 2005).