Fig. 5. Differential effects of stau and vas mutants on GFP-Aub localization. (A) Posterior portion of a stage 10 stau mutant oocyte. GFP-Aub localization at the posterior pole is virtually eliminated. (B) stau mutant nurse cell. The appearance of GFP-Aub in perinuclear particles is unaffected. (C) vas mutant nurse cell. The perinuclear clustering of GFP-Aub particles is largely abolished. Occasionally, one or two particles may be seen. (D-E) vas heterozygous stage 10 oocyte. Both GFP-Aub (D) and Osk (E) are concentrated at the posterior pole as in wild-type. (F-G) vas mutant late stage 10 oocyte. GFP-Aub (F) localization to the posterior pole is dramatically reduced, while the level of posteriorly localized Osk (G) remains essentially normal. Although this result differs from published reports of a substantial decrease in the level of Osk protein in vas mutant ovaries, the earlier studies compared average protein levels throughout the ovary and did not differentiate between different stages of oogenesis (see text).