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Fig. 3. Nuage particle movement in nurse cells. All panels show GFPAub except E, where ExuGFP particles are detected. The dashed lines in B, C, F, and G delineate the oocyte-nurse cell boundaries. (A) Representative movements of GFPAub particles in a nurse cell of a stage-9 egg chamber. A time projection of ten images (each taken 6 seconds apart) is shown, with the arrows aligned next to moving particles to indicate the direction and distance of migration. A ring canal connecting to the oocyte is out of the field to the top right of the image. (B) Nuage particles concentrated near the ring canals of a stage-9 egg chamber. The ring canals (rc; large gaps in dashed line) connect the nurse cells to the oocyte. The particle movements in this field are shown in the time projection in C, which represents 15 images captured at 6 second intervals. The small arrows indicate particles that are traversing the ring canals into the oocyte, the arrowheads indicate relatively immobile particles near the ring canals, and the large arrows indicate rapidly moving particles in other cytoplasmic regions. (D) Exclusion of GFPAub from regions of the cytoplasm. Structures appearing circular in cross section lack cytoplasmic GFPAub (arrows) and are sometimes clustered near ring canals along with nuage particles (arrowheads). (E) Clustering of relatively immobile ExuGFP structures near ring canals. This field was imaged for 10 minutes and showed very little movement of the particles (data not shown). (F,G) Onset of nurse-cell to oocyte transport at stage 8. For the stage-8 egg chamber in F, a much smaller data set was collected by imaging a single focal plane at one-minute intervals for four repetitions. In this and other experiments, particles were easily detected in passage through ring canals (arrow). For the stage-7 egg chamber in G, a large fraction of all possible particle movements were tracked by imaging at multiple focal planes and repeating the imaging at one-minute intervals for 20 repetitions. The data are presented as a z-series and time projection, and reveal no transport of particles into the oocyte. Scale bars, 5 µm (A,D), 8 µm (C), 10 µm (B,F,G), and 20 µm (E).
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t=1 minute) in multiple z-planes, with the data shown as a combined z-axis and time series projection. The arrows are positioned next to a subset of the moving particles and show the direction and path of movements. (B-D) GFPAub in different regions of a single egg chamber, images were taken from a series of scans performed at one-minute intervals. B and C are the first and last scans of the series and show that the movement of nuage particles follow general cytoplasmic movements. The arrows show the direction of and the distance covered by a nuage particle (small arrow) and a yolk platelet/vesicle (large arrow) in this time interval. The yolk platelet/vesicles (which appear black because they lack cytoplasmic GFPAub fluorescence) provide a simple means of tracking general cytoplasmic movements. D shows that particle movements near the posterior pole of the oocyte particle movements are restricted. The arrow shows the rapid movement of a nuage particle at the anterior (the same particle whose movement is shown by the small arrows in B and C), whereas a particle close to the posterior (arrowhead) is relatively immobile. These results are typical of those obtained in multiple additional experiments. The dashed line in A delineates the oocyte nurse-cell boundary. Scale bars, 7 µm (B-D) and 10 µm (A).
