Fig. 2. csul activity contributes to nuage and pole plasm assembly during oogenesis. Distribution of Osk (A,B), GFP-Vas (C,D,G,H), Tud (E,F,I,J), and Mael (K,L) proteins in stage 10 egg chambers (A-F) and previtellogenic egg chambers (G-L). Left and right columns show wild-type and csul^P egg chambers, respectively. (A,B) Osk immunostaining (red) and DNA (green). Osk is correctly synthesized and positioned at the posterior pole of csul^P oocytes. (C,D,G,H) GFP-Vas (green) and DNA staining (red). GFP-Vas is only detected in the nuage of previtellogenic csul^P egg chambers and disappears in later stages of egg chamber development. In comparison with wild type, the amount of GFP-Vas is markedly reduced in the pole plasm of csul^P stage 10 oocytes. (E,F,I,J) Tud immunostaining (red) and DNA (green). Although Tud is synthesized in csul^P egg chambers, it is absent both from nuage and pole plasm. (K,L) Mael immunostaining. Mael localization in the nuage is abolished in csul^P egg chambers. o, oocyte; n, nurse cell nucleus.