Fig. 4.
Contributions of parts of stem-loop 2b to transport of osk mRNA to the oocyte. (A) Effects of small deletions in SL2b on osk mRNA transport to the oocyte. Each transgene was tested as a single copy in the osk RNA null background, with the transgene RNA detected by in situ hybridization. The upper and lower panels are identical, except that the signal intensity was increased in images shown in the upper panel in order to always display the entire egg chamber (this also resulted in saturation of signal intensities for some samples; lower panel provides a better display of the efficiency of RNA transport). See Fig. S1 for transgene RNA levels. All egg chambers in A and B are previtellogenic stages. (B) Effect of deleting the entire SL2b on osk mRNA transport to the oocyte. The panels are as in A. (C) Quantification of RNA distributions as in Fig. 1. The gray line at the ratio of 1 indicates the value for equal RNA levels in oocyte and nurse cells. P values from t-tests are indicated above the plot. Where multiple P values are shown above a single horizontal line, the comparisons are all relative to the sample indicated by the longest vertical line. The lower set of pairwise comparisons of means indicates that the RNA transport defect of mutant Δ706-723 is intermediate between those of mutants Δ636-652, Δ665-685 and Δ688-705 (all with stronger transport) and mutant Δ634-742 (with weaker transport). (D) Proposed structure of SL2b (Jambor et al., 2011) with the positions of deletions indicated. The Δ61 mutant is GFP-oskΔ61, which is largely defective in oocyte transport (Kim et al., 2014). All scale bars: 25 µm; all images in panel A are at the same magnification. Likewise, all images in panel B are at the same magnification.