Fig. 5. Differential sensitivity of the three pacemakers to cytoskeletal inhibitors. Patterns of [Ca²⁺]c oscillations triggered by fertilization (A,C-E) or after photorelease of cgPtdIns(4,5)P₂ (B,C,F) in ascidians eggs perfused with nocodazole (A,B) or cytochalasin B (C-F) or both (B). The green arrowheads indicate the time of perfusion of the cytoskeletal inhibitors nocodazole (noc) or cytochalasinB (cytoB). Interruptions in the graphs are due to the fact that no measurements could be made during the time of perfusion. The black arrowheads mark the time of fertilization (f), while the red arrowheads indicate the time at which a UV flash is applied to uncage cgPtdIns(4,5)P₂.