Time-lapse videos of examples of a centrifuged control (left) and six GV-reversed oocytes (right). Oocytes were oriented so that the eventual GV position is upward. The original GV position that was stained in blue is up in the centrifuged control, while it is down in the six GV-reversed oocytes. Thus, cortical flow is downward in every movie. Movies were recorded for 2 h and played at 30 frames per second. In the oocyte shown in the bottom middle panel, note that the MA quickly reached the cortex (the trajectory is traced by the green line) but the cortical flow continues long after the MA movement. There are many small test cells between the oocyte surface and vitelline membrane. Test cells, which are clearly visible in centrifuged control, are maternal accessory cells specifically present in ascidian eggs.