Fig. 4. Loss of pxt and COX inhibitors disrupt actin bundles required for nurse cell dumping. (A-F') Actin bundles in wild-type nurse cells in cytoplasmic (A,A') and subcortical regions (D,D') are greatly reduced in pxt^-/- mutants (B,B' and E,E', respectively), and restored by expression of MCOX1 under the control of HS GAL4 (C,C' and F,F'). (G-I) Actin bundles in stage 10B egg chambers developed in vitro until stage 11 in the absence (G) or presence (H) of 1.5 mM aspirin, or with aspirin and 60 µM PGH₂ (I). The presence of aspirin disrupts subcortical actin and causes actin aggregation in dumping nurse cells (H), which is partially reversed by PG addition (I). A-F are projections of several confocal sections. A'-F' are zoomed images of one nurse cell from the adjacent image. Red is phalloidin and blue is DAPI. (E-G) Epifluorescent images. Scale bars: 50 µM.