Ann Morris from the University of Kentucky studies the zebrafish (Danio rerio). In particular, she studies the ability of zebrafish retinas to regenerate following retinal injury or damage. Retinal regeneration is an interesting phenomenon that mammalians seem to lack and yet zebrafish manage to do this despite having a retina that in many ways is far more complex than the mammalian retina.
Ann talks about her work in the following video from the University of Kentucky:
There are a number of possibilities of why zebrafish can regenerate their retinas while human cannot… As Ann notes:
“One is that everybody had the ability to regenerate, and that ability in certain lineages was eventually lost,… So as mammals evolved, somehow they lost the ability to regenerate neurons, but perhaps the mechanism is still there, in their genome, so we need to find those switches and turn it back on… The other possibility though is that certain vertebrates evolved that ability whereas others didn’t. And so it’s possible that mammals can’t regenerate neurons because they just don’t have that mechanism. I happen to believe it’s probably more of the former, that some of those abilities are there and they’re latent and we have to discover how to reactivate them.”
Image Credit: Bryan William Jones, Ph.D.