Developing and regenerating neurons induce genes whose products are necessary for axonal growth, such as that encoding alpha1 tubulin. To determine whether alpha1 tubulin gene induction uses similar mechanisms during CNS development and regeneration, we compared wild-type and mutant alpha1 tubulin promoter activity in the developing and regenerating CNS of transgenic zebrafish. Wild-type alpha1 tubulin promoter activity increased dramatically in the developing and regenerating CNS. In contrast, we generated a mutation in the alpha1 tubulin promoter that prevented its increase during development but retained regeneration-dependent induction in the adult. These results suggest that at least some of the signaling mechanisms used to activate alpha1 tubulin promoter activity during CNS regeneration are different from those used to activate this promoter during development.