Distinct expression of two types of Xenopus Patched genes during early embryogenesis and hindlimb development

Patched (Ptc) is a putative twelve transmembrane domain protein that is bot h a Hedgehog (Hh) receptor and transcriptional target of Hh. In this study, we isolated Xenopus Pre cDNAs, Ptc-1 and Ptc-2, and carried out comparativ e analyses on their expression patterns. The putative Ptc-2 protein has a l ong C-terminal extension that has similarities in both length and sequence to those of Ptc-1 proteins in mouse, chick and human. In both early embryog enesis and hindlimb development, Ptc-2 expression is restricted to cells th at receive a Hh signal, a pattern similar to that of Gli-1. Ptc-1, however, shows a broader distribution, mainly non-overlapping with that of Ptc-2. D espite the difference in their expression patterns, both are induced in ani mal cap explants synergistically by Shh and Noggin, showing a conserved reg ulation in their activation mechanisms. (C) 2000 Elsevier Science Ireland L td. All rights reserved.