Duox is the primary NADPH oxidase responsible for ROS production during adult caudal fin regeneration in zebrafish.

Sustained elevated levels of reactive oxygen species (ROS) have been shown to be essential for regeneration in many organisms. This has been shown primarily via the use of pharmacological inhibitors targeting the family of NADPH oxidases (NOXes). To identify the specific NOXes involved in ROS production during adult caudal fin regeneration in zebrafish, we generated mutants for , and (a key subunit of NOXes 1-4) and crossed these lines with a transgenic line ubiquitously expressing , which permits the measurement of ROS levels. Homozygous mutants had the greatest effect on ROS levels and rate of fin regeneration among the single mutants. However, : double mutants showed a greater effect on fin regeneration than the single mutants, suggesting that Nox1-4 also play a role during regeneration. This work also serendipitously found that ROS levels in amputated adult zebrafish fins oscillate with a circadian rhythm.