Goss and Toomre show that during cytokinesis both daughter cells pitch in to supply new membrane.
Researchers suspect that during cytokinesis, fresh membrane shuttles to the junction between the two daughter cells. Where the membrane comes from has puzzled researchers. A previous study using spinning disc confocal microscopy suggested that only one daughter cell provides it. However, that study didn't track individual membrane vesicles.
Goss and Toomre were able to do just that by capturing images 60 times faster. They found that vesicles from both daughter cells leave the Golgi apparatus and cruise to the cleavage furrow, accumulating there. Although other potential sources of membrane, including endosomes, also collect near the furrow, they remain aloof from the Golgi-derived vesicles that will ultimately fuse with the cell membrane.
With total internal reflection fluorescence microscopy, the team observed individual vesicles from both daughter cells merging with the plasma membrane at the cleavage furrow. However, the results don't necessarily conflict with the previous study, the researchers say. They note that they also observed an asymmetric stage in which only one cell appears to direct vesicles to the cleavage furrow.