This cell had an active lamellipodium but remained stationary during the period of observation. The bleached spot, created at the very edge of the cell, moves toward the cell center, suggesting that actin monomers are adding continuously at the leading edge and pushing the filaments backwards. In addition the other end of the filament must undergo disassembly or fragmentation to maintain a constant width of lamellipodia. Large number indicates the time in seconds after photobleaching. Recording time, 5 min. |