RT Journal
A1 Satoh, Akira
A1 James, Michelle A.
A1 Gardiner, David M.
T1 The Role of Nerve Signaling in Limb Genesis and Agenesis During Axolotl Limb Regeneration
JF The Journal of Bone & Joint Surgery
JO The Journal of Bone & Joint Surgery
YR 2009
FD July 1
VO 91
IS Supplement_4
SP 90
OP 98
DO 10.2106/JBJS.I.00159
UL http://dx.doi.org/10.2106/JBJS.I.00159
AB 
Vertebrate appendages such as limbs and fins share evolutionarily conserved mechanisms for development and regeneration, implying that they evolved from an appendage that arose on a common ancestor1. This conservation of developmental mechanisms is one of the fundamental discoveries of molecular genetics and is the basis for our emerging understanding of the evolution of animal genomes. The molecules involved in the signaling pathways that regulate limb development are not only conserved at the level of nucleotides and/or amino acids but also at the functional level, so that experimentally substituting homologous genes between species as divergent as humans and Drosophila can rescue the function of a mutant gene2. The fact that this remarkable degree of conservation has been maintained over the course of evolution implies that the mechanisms for appendage development have evolved once. Similarly, the mechanisms regulating limb regeneration are largely the same as those regulating limb development3,4, and thus evolution appears to have selected for a conserved set of signaling pathways that regulate both vertebrate limb development and regeneration.