Fig. 4. Effects of CSN5 mutations on the AP axis. (A-H) CSN5 is required for proper localization of bcd and osk RNAs. (A,B) In CSN5-mutant oocytes, bcd RNA is often present diffusely throughout the oocyte. In addition, the amount of bcd RNA at the anterior end of the oocyte may be reduced and there may be central bcd RNA concentrations. (E,F) In embryos the effects of CSN5 mutations on bcd RNA localization are less extreme. Some embryos do show dorsally displaced bcd RNA. (C,D) In CSN5-mutant oocytes, little osk RNA is localized at the posterior pole. Instead it is often present throughout the oocyte cytoplasm or in central concentrations. (G,H) In some mutant embryos, osk RNA is posteriorly localized, but is strongly reduced and sometimes shifted dorsally. (I-K) CSN5 may affect localization and number of pole cells. In agreement with the osk RNA results, anti-Vasa staining often shows a reduced number of pole cells (J). In some cases the pole cells were not tightly clustered (K).