The role of reactive oxygen species in zebrafish caudal fin regeneration

Abstract

A sustained increase in ROS is essential for regeneration to occur in various models systems ranging from the fin in zebrafish, to the tail in frogs, salamanders and geckos. This effect of ROS has been, so far, demonstrated using pharmacological inhibition to target various sources of ROS including the transmembrane NADPH oxidases (NOXes). To focus on the role of NOXes in regeneration, we generated nox mutants by targeting duox, nox5 and cyba (a key subunit of NOXes 1-4). We confirmed that mutations led to Aspergillus susceptibility in cyba mutants, congenital hypothyroidism in duox mutants, and anaesthesia tolerance in nox5 mutants. These individual commentaries on the various Noxes, while not immediately related to regeneration, authenticate the strains as functional mutants. To estimate their individual contribution to ROS production these mutants were generated in a transgenic background, HyPer, which specifically helps visualise H2O2 flux. We found that ROS levels remain elevated for up to two weeks post-amputation in wild type animals, but only a week among nox mutants. A consequence of this reduced ROS flux was a significantly reduced rate of caudal fin regeneration among cyba and duox mutants. We also provide clues into the possible temporal distribution of Nox activity post-amputation. Finally, we show that ROS levels, both in the amputated and unamputated state, oscillate during the day.

Date of Award	1 Aug 2020
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Enrique Amaya (Supervisor) & Ralf Paus (Supervisor)