Fig. 6. Rbsn-5 is required for Osk-mediated F-actin reorganization and the anchoring of pole plasm components in Drosophila. (A-D) Wild-type (A,B) or rbsn-5^- (C,D) oocytes, without (A,C) or with expression of osk-bcd 3' UTR (B,D), were stained for Osk and F-actin. Enlargements of the bracketed regions are shown in the right panels. Aberrant F-actin aggregates (magenta) that contained Osk (green) were observed around the anterior region in the rbsn-5^- oocyte when the osk-bcd 3' UTR transgene was expressed (arrowheads in D). (E-H) Tud protein localization in wild-type (E,F) or rbsn-5^- (G,H) oocytes without (E,G) or with expression of osk-bcd 3' UTR (F,H). Arrowheads in H indicate aberrant aggregates containing F-actin and Tud. (I-N) Rab5 (I,J), Rab11 (K,L) and Rab7 (M,N) localization to the oocyte anterior without (I,K,M) or with expression of osk-bcd 3' UTR (J,L,N) in rbsn-5^- GLCs. Arrowheads point to the accumulation of endosomal proteins in areas of ectopic Osk expression. DNA was counterstained with DAPI (cyan). Scale bars: 20 µm.