Fig. 4

Ductin and Inx3 are partly colocalized in plasma membranes of follicle cells and germ-line cells, but often in different plaques. a to c: Ductin; a’ to c’: Inx3; a” to c”: merged images, ductin (red), Inx3 (green) and colocalization of both (yellow), WFM. Nuclei were stained with DAPI. No specific staining was obtained with NIS (inset in b). In previtellogenic and early vitellogenic follicles (a to a”, stage 6, left, and stage 9, right), ductin and Inx3 co-occur in follicle-cell membranes (FCM). While ductin is found to be enriched in nurse-cell membranes (NCM), in the oolemma (Ool), in polar cells (PC), in stalk cells (SC) and in the cytoplasm of NC and oocyte (Ooc), Inx3 is enriched especially in lateral membranes of the prospective centripetally migrating FC (cFC) and around NC nuclei (NCN). In later stages (b to b”, surface view, and c to c”, optical median section, stage 10b), ductin and Inx3 co-occur in lateral FCM (FCN, FC nucleus) and in NCM. While Inx3 exhibits prominent membrane plaques (b’), ductin is enriched in apical FCM (aFCM) and in the Ool c. Both proteins are concentrated in lateral FCM, but they often localize in different plaques (cf. arrowheads in c and c’ and arrows in c”). Scale bars, 10 μm