Fig. 7. Basal localization of E-Cad is disrupted in a Ras clone on the dorsal midline. Basal confocal projections of E-Cad fluorescence in (A) wild-type and (B-E) Ras mosaic egg chambers reveal a novel, Ras-dependent pattern of basal E-Cad localization. Anterior is to the left in all panels. DM, dorsal midline (confirmed by position of oocyte nucleus, not shown). (A) During dorsal appendage morphogenesis, E-Cad is localized basally in an anterior patch of dorsal midline follicle cells as well as several rows of anterior follicle cells encircling the egg chamber. Note that all cells exhibit some degree of basal E-Cad fluorescence, but the level of basal localization in midline and anterior cells is much higher. (B) This stage 10B mosaic egg chamber bears two Ras clones, marked by lack of myc. The anterior clone resides in the dorsal midline region that normally displays basal E-Cad. (C,D) Basal E-Cad is greatly reduced in the Ras mutant cells. (E) An enlargement of the boxed region in C reveals the cell non-autonomous effect of the Ras mutant clone on basal E-Cad protein in neighboring wild-type cells, which have lost basal E-Cad on cell surfaces abutting the Ras clone (arrowhead).
