CONSERVATION OF THE HEDGEHOG PATCHED SIGNALING PATHWAY FROM FLIES TO MICE - INDUCTION OF A MOUSE PATCHED GENE BY HEDGEHOG/

The signaling protein Hedgehog (Hh) controls cell fate and polarizes t issues in both flies and vertebrates. In flies, Hh exerts its effects by opposing the function of a novel transmembrane protein, Patched, wh ile also locally inducing patched (ptc) transcription. We have identif ied a mouse homolog of ptc which in many tissues is transcribed near c ells making either Sonic or Indian hedgehog. In addition, ectopic Soni c hedgehog expression in the mouse central nervous system induces ptc transcription. As in flies, mouse ptc transcription appears to be indi cative of Hedgehog signal reception. The results support the existence of a conserved signaling pathway used for pattern formation in insect s and mammals.