Wound-induced Ca²⁺ signaling is important for late regeneration. (A) Kymograph in the rectangular box in B. The rectangular box was summed into a 1D line, and the kymograph was made. (B) Time-lapse imaging of GCaMP3 in a 2-dpf larva immediately after wounding (see Video 1). (C) GCaMP3 images in DMSO- or thapsigargin-treated 2-dpf larvae (Video 2). (D) H₂O₂ imaging with HyPer in DMSO- or thapsigargin-treated 2-dpf larvae. Thapsigargin does not inhibit H₂O₂ burst at wounds. (E) Immunofluorescence of pSFK and pErk in DMSO- or thapsigargin-treated 2-dpf larvae. Thapsigargin did not inhibit pSFK or pErk at wounds. (F) Quantification of tail fin length at 3 d after treatment (+wound/DMSO: 23 larvae; +wound/thapsigargin: 32 larvae; +wound/U73122: 32 larvae; −wound/DMSO: 21 larvae; −wound/thapsigargin: 32 larvae; −wound/U73122: 30 larvae). Horizontal lines indicate means. (G) Representative pictures at 3 d after treatment. 2-dpf larvae were treated and wounded as described in Fig. 2 A. Dotted lines indicate tail transection. *, P < 0.05; one-way ANOVA with Dunnett’s posttest. Ex, excitation. Bars, 50 µm.