CLONING AND EXPRESSION OF THE AXOLOTL PROTOONCOGENE SKI

In vitro and in vivo overexpression studies have demonstrated that the c-ski proto-oncogene can influence proliferation, morphological transformation and myogenic differentiation. We report the isolation and expression of an axolotl (Ambystoma mexicanum) c-ski (aski) gene. Sequence analysis revealed a high degree of nucleotide and predicted amino acid (AA) homology with mammalian and anuran c-ski, showing the highest conservation to Xenopus laevis c-ski (74% nucleotide and 87% AA). Northern analysis showed that axolotl c-ski is expressed in unfertilized eggs and at increasing levels in embryos from blastula to tadpole stage. c-ski expression was also detected in larval limb muscle and in several stages of regenerating limb blastemas. These data indicate that axolotl c-ski is highly conserved among amphibians and mammals and suggests that it plays a role in urodele embryogenesis and limb regeneration.