{HEAD ~ The present invention} concerns the discovery that proteins encoded by a family of vertebrate genes, termed here hedgehog related genes, comprise morphogenic signals produced by {TAIL ~ embryonic patterning centers}, and are involved in the formation of ordered spatial arrangements of differentiated tissues in vertebrates 
{ HEAD ~ The present invention } concerns the discovery that proteins encoded by a family of vertebrate genes , termed here hedgehog related genes , comprise morphogenic signals produced by { TAIL ~ embryonic patterning centers } , and are involved in the formation of ordered spatial arrangements of differentiated tissues in vertebrates
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH