Wnt-3a is expressed in the blastema of both froglets and tadpoles.

(A) RT-PCR of the total RNA from tadpole blastemas at 5 dpa or froglet blastemas at 9 dpa showed that_wnt-3a was expressed in both the tadpole and froglet blastemas. (B) In situ hybridization of froglet blastemas at 9 dpa with a wnt-3a antisense probe revealed expression of wnt-3a in the epidermal layer of the blastema, while no specific signal was detected with the wnt-3a sense probe. Each section was hybridized with the antisense or sense probe, at the same time and by the same procedure, and the development of the staining reaction was stopped at exactly the same time. The lines indicate the estimated amputation plane. Scale bar = 100 µm.