Fig. 4. Restriction of GFP-Nos to the posterior requires the nos 3'UTR. All images are confocal projections of fixed oocytes. The muscular sheath that encases the ovary is still attached in these preparations as revealed by staining with rhodamine-phalloidin (red). (A) Control oocyte lacking GFP-Nos. (B) Stage 13 6 x gfp-nos oocyte with GFP-Nos gradient emanating from the posterior pole. (C) Stage 13 gfp-nos:tub3'UTR oocyte displaying a uniform distribution of GFP-Nos.