During late oogenesis, Drosophila oocyte cytoplasm undergoes circular movement called ooplasmic streaming. Posterior determinants containing the fluorescently labeled marker Staufen move with the cytoplasmic flow, but dramatically slow down near the posterior pole in a wild-type oocyte (right) but not in an oocyte expressing a dominant-negative form of myosin V (left). Spectrum-colored tracks represent the movement of Staufen-containing particles within a 10-min period of time.

Microtubules are connecting the nurse cells with the oocyte through the actin-rich channels (ring canals). Microtubules are labeled the GFP-tagged Patronin and F-actin is stained with Rhodamine-conjugated Phalloidin.

Stable immotile microtubules are closely associated with cortical actin in a streaming oocyte. Microtubules are labeled with the K560Rigor-SunTag system (MT-SunTag) and F-actin is stained with Rhodamine-conjugated phalloidin.

During late oogenesis, Drosophila oocyte cytoplasm undergoes circular movement called ooplasmic streaming. Posterior determinants containing the fluorescently labeled marker Staufen move with the cytoplasmic flow, but dramatically slow down near the posterior pole in a wild-type oocyte (left), but not in an oocyte expressing a dominant-negative form of myosin V (right) . Scale bar, 50 µm.