Fig. 8. Rtnl1GFP colocalizes with components of RNP complexes on both the fusome-ER and the oocyte-ER. (A-A'") The DEAD-box protein Me31b, which is involved in translational silencing of mRNAs and a component of RNP complexes, colocalizes with Rtnl1-GFP and Orb on the central portion of the fusome in germaria. Shown is a z-stack projection of a germarium. Rtnl1GFP is green, Me31 is red, and Orb is blue in A, with the respective single channels shown in A'-A'". Arrowheads in A point to the colocalization on the central portion of the fusome. (B-B'") Sec61
-GFP shows strongest labeling of the fusome in region 2a, where neither Orb nor Me31b are concentrated yet, and no further colocalization within the germarium is observed. Sec61
-GFP is green, Me31 is red, and Orb is blue in B, with the respective single channels shown in B'-B'". (C-F) Rtnl1-GFP, Me31b and also Trailer Hitch (Tral), another component of RNP complexes, colocalize in punctate structures in the oocyte (C-C'" for Rtnl1GFP versus Me31b and Trailer Hitch, and E-E" for Rtnl1GFP versus Me31b alone) and nurse cells (D-D'" for Rtnl1GFP versus Me31b and Trailer Hitch, and F-F" for Rtnl1GFP versus Me31b alone). Shown are single confocal sections of a stage 6-7 egg chamber. In all composites Rtnl1GFP is in green, Me31b is in red and Tral is in blue. Arrowheads in C and D point to some of the colocalizing foci of Rtnl1GFP, Me31b and Tral. (G-K) Comparison of the localization of Me31b and Sec61
-GFP and Me31b and PDI-GFP. Both Sec61
-GFP and PDI-GFP are strongly concentrated in the entire oocyte and do not show foci of stronger labeling where Me31b is concentrated into foci (G for Sec61
-GFP and I for PDI-GFP). Within the nurse cells, Me31b foci colocalize with labeling for Sec61
-GFP and PDI-GFP (H for Sec61
-GFP and K for PDI-GFP). In all composites Sec61
-GFP and PDI-GFP are in green, Me31b is in red. Bars, 10 µm.