Figure 2

Design of microarray experiment. A) Timeline showing the treatments used to generate tissue for arrays. hs = heat shock, 30 minutes at 34°C. B) Stage 52 hindlimb buds were bilaterally amputated at the level of the future ankle (dotted line), defined by the anterior indentation, to remove the autopod. Knee level is marked by black arrowhead for orientation. Heat shocks were applied to both WT and N1 tadpoles as depicted in (A). After 3 days the blastemas were removed from the WT limbs and pseudoblastemas from the N1 limbs. BMP signalling is inhibited in the N1 limb buds, due to expression of Noggin from an inducible transgene, preventing successful regeneration. Pools of 20 blastemas or pseudoblastemas were used to extract RNA to generate microarray probes.