Back to Search Start Over

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

Authors :
Butterfield NC
Metzis V
McGlinn E
Bruce SJ
Wainwright BJ
Wicking C
Source :
Development (Cambridge, England) [Development] 2009 Oct; Vol. 136 (20), pp. 3515-24.
Publication Year :
2009

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.

Details

Language :
English
ISSN :
1477-9129
Volume :
136
Issue :
20
Database :
MEDLINE
Journal :
Development (Cambridge, England)
Publication Type :
Academic Journal
Accession number :
19783740
Full Text :
https://doi.org/10.1242/dev.037507