Patched 1 is a crucial determinant of asymmetry and digit number in the vertebrate limb

Natalie Butterfield, Vicki Metzis, Edwina McGlinn, Stephen Bruce, Brandon J Wainwright, Carol Wicking

Research output: Contribution to journalArticleResearchpeer-review

41 Citations (Scopus)

Abstract

The vertebrate hedgehog receptor patched 1 (Ptc1) is crucial for negative regulation of the sonic hedgehog (Shh) pathway during anterior-posterior patterning of the limb. We have conditionally inactivated Ptc1 in the mesenchyme of the mouse limb using Prx1-Cre. This results in constitutive activation of hedgehog (Hh) signalling during the early stages of limb budding. Our data suggest that variations in the timing and efficiency of Cre-mediated excision result in differential forelimb and hindlimb phenotypes. Hindlimbs display polydactyly (gain of digits) and a molecular profile similar to the Gli3 mutant extra-toes. Strikingly, forelimbs are predominantly oligodactylous (displaying a loss of digits), with a symmetrical, mirror-image molecular profile that is consistent with re-specification of the anterior forelimb to a posterior identity. Our data suggest that this is related to very early inactivation of Ptc1 in the forelimb perturbing the gene regulatory networks responsible for both the pre-patterning and the subsequent patterning stages of limb development. These results establish the importance of the downstream consequences of Hh pathway repression, and identify Ptc1 as a key player in limb patterning even prior to the onset of Shh expression.
Original languageEnglish
Pages (from-to)3515 - 3524
Number of pages10
JournalDevelopment
Volume136
Issue number20
DOIs
Publication statusPublished - 2009
Externally publishedYes

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