Fig. 6. Balbiani body-derived mitochondria associate with the germ plasm prior to nurse cell dumping. (A) Mitochondria labeled with anti-ATP synthase (green) congregate on the posterior side of the GV (arrowhead) in stage 6-7 egg chambers. Green, ATP synthase; red, germ cells (Vasa); blue, ring canals (anti-Phosphotyrosine). (B) By contrast, mitochondria (green) in the nurse cells adjacent to the oocyte accumulate (arrowheads) at the ring canals (blue), but fail to enter the oocyte until nurse cell dumping (see Table 2). Green, ATPsynthase; red, Vasa; blue, phosphotyrosine. (C) At stage 9, a few mitochondria (green) associate with the germ plasm, which has begun to coalesce at the oocyte posterior as revealed by Vasa staining (red). Green, ATPsynthase; blue, Phosphotyrosine. (D,D'). By stage 10A, mito-GFP-labeled mitochondria (green) are abundant in the germ plasm (arrowheads in D'). D' shows a higher magnification. Green, mito-GFP; red, Vasa; blue, actin-rich membranes (phalloidin). (E) A summary of the structure and assembly of the Drosophila Balbiani body. Green arrows indicate direction of movement along the fusome (red) towards the oocyte. Scale bars: in C, 10 µm for A-D; in D', 5 µm for D'.