Mechanical detachment of PFCs from the oocyte causes posterior accumulation of Bazooka. (A) Schematic showing experimental assay to mechanically detach PFCs from the oocyte. A holding micropipette is used to aspirate and pull on the PFCs. (B) Time-lapse images of an egg chamber expressing Baz::GFP (yellow) and the microtubule reporter Jupiter::mCherry (magenta) following detachment of PFCs from the oocyte. Top: merged channels, middle: Baz::GFP, bottom: Jupiter::mCherry. Formation of the intercellular space and accumulation of Bazooka are detected at the posterior (arrowheads). Scale bar, 20 μm (C) The average intensity profile of Baz::GFP signal at the posterior of the oocyte, measured along the oocyte cortex as represented by the white line in the inset image. The blue curve is the intensity measured before the PFCs were pulled and the orange curve is the intensity after 60 min of continuous pulling. The shaded region designates the SD. The x-axis origin represents the position of the polar cells. n is the number of experiments. (D) Intensity profile of Baz::GFP (yellow) and Jupiter::mCherry (magenta) along the line crossing cell boundaries from the oocyte to posterior follicle cells, as shown in the inset. The x-axis origin and vertical line represent the local minimum of the Jupiter::mCherry signal, which we interpret as intercellular space between the oocyte and the follicle cells.