LAUSR

It has recently been shown that tail regeneration in Xenopus tadpoles require a sustained increase in the production of reactive oxygen species (ROS). We have also found that embryos are associated with sustained high levels of ROS, which are also needed for tissue development to proceed. It is not entirely clear what is the source of ROS during embryogenesis and following injury, and whether it is identical for both processes. Furthermore, it is unclear what specific type(s) of ROS are required for either process. One of the primary aims of this project is to identify the source of ROS and their nature, during embryogenesis and following injury. In both cases, particular focus is made on hydrogen peroxide (H2O2) and its precursor superoxide (O2-). A second primary aim is to determine the downstream targets of O2and H2O2, particularly during tissue formation, repair and regeneration. To address these aims a model with high regenerative capacity has been chosen, namely frog embryos and tadpoles. Characterisation of specific ROS involved is made possible through the use of the electron paramagnetic resonance (EPR) spectroscopy and fluorescent imaging. Ultimately, we are investigating: to what extent developmental processes are reactivated during regeneration, in the context of ROS; and whether manipulating specific ROS levels might provide a mechanism by which we may induce and sustain a better, more complete regenerative response in humans, following injury.