Voltage-gated calcium channels generate blastema Ca fluxes restraining zebrafish fin regenerative outgrowth.

Adult zebrafish fins regenerate to their original size regardless of damage extent, providing a tractable model of organ size and scale control. Gain-of-function of voltage-gated K channels expressed in fibroblast-lineage blastema cells promotes excessive fin outgrowth, leading to a long-finned phenotype. Similarly, inhibition of the Ca -dependent phosphatase calcineurin during regeneration causes dramatic fin overgrowth.