The study of regenerative biology aims to understand the mechanisms and limitations of endogenous regenerative capacity. Although terrestrial vertebrates are able to heal wounds and regrow many tissues such as skin and muscle, the regeneration of complex structures is limited to the liver, kidney and digit tip. Aquatic vertebrates on the other hand, are able to regenerate large portions of organs including limb, tail, spinal cord, retina and heart. When comparable damage occurs in mammals, tissue fails to regrow and scarring occurs. Organ regeneration requires many of the same signalling pathways that are deployed during initial development indicating that reinitiation of developmental signalling plays an important role. One possible explanation for the poor regenerative potential observed in mammals is that damage does not reinitiate developmental signalling. Thus, the elucidation of the mechanism by which tissue damage triggers developmental signalling pathways is crucial to further our understanding how successful regeneration takes place.
A second reason for poor mammalian regeneration may be a failure to recruit competent cells to the site of injury in sufficient numbers to restore the missing tissue. Studies of organ regeneration in aquatic species indicate that regenerative cells originate from a diverse array of sources. Current studies suggest that mature cells can restore missing tissue, but that stem cells may provide an alternative source of regenerative cells. The robustness of highly regenerative species suggests that mammalian organ regeneration may be enhanced if large enough numbers of regenerative cells were recruited to the damaged site. Therefore, the identification of the mechanisms that recruit cells to contribute to regeneration may help to facilitate regeneration in mammals.
The Roehl Laboratory uses zebrafish as a model to study how regeneration takes place in a simple aquatic vertebrate. Our studies are focused upon addressing the two key questions outlined above. We hope that our results may one day provide information that may enhance clinical approaches to the treatment of injury and disease.