Re-examining jaw regeneration in urodeles: what have we learnt?

Urodele amphibians can regenerate not only their limbs and tails, but also their upper and lower jaws rather faithfully. However, relatively few studies of jaw regeneration in amphibians have been carried out, especially in recent years. It is therefore important to reexamine thoroughly this regenerating system, since the advent of sophisticated morphological techniques and the development of molecular approaches offer the promise of renewed and rapid progress in our understanding of complex developmental problems such as this. This paper briefly reviews some of the early research on jaw regeneration, some of the fundamental questions which have been asked and have yet to be answered, and the work we have carried out in order to understand the molecular mechanisms underlying jaw regeneration in the newt, Notophthalmus viridescens. In addition, some aspects of jaw regeneration will be discussed in relation to regeneration of the adult limb.