Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published January 10, 1996 | public
Journal Article

Digit Induction by Hensen's Node and Notochord Involves the Expression of shh but Not RAR-β2

Abstract

It is well established that Hensen's nodes can induce the formation of supernumerary digits after grafting into the anterior margin of the developing limb bud. The recent finding that distinct mesodermal cell populations are segregated within the node has made it possible to isolate different prospective cell types in an attempt to correlate digit-inducing ability with cell fate. We find that the prospective notochord cells contained within Hensen's node are able to induce supernumerary digits, whereas presumptive somite cells cannot. This early difference in inducing ability persists into later stages of development: epithelial somites are unable to induce while notochord from all lengths of the neuraxis continues to induce. Using probes to retinoic acid receptor-β2 and sonic hedgehog (shh) we find no evidence to support the idea that inducing tissues generate extra digits by releasing retinoic acid into adjacent limb tissue but find that the inducing ability of a tissue correlates with its expression of shh.

Additional Information

© 1996 Academic Press, Inc. Received 14 June 1995, Accepted 31 October 1995, Available online 7 May 2002. We are grateful to Drs. David Gardiner and Mary Dickinson and the anonymous reviewers for helpful comments on the manuscript. We thank Bruce Blumberg and Kaz Umesono for the RAR-β2 probe and Juan Carlos Izpisua-Belmonte for the ssh probe. M.A.J.S. was supported by a Muscular Dystrophy Association research fellowship. Research was supported by HD25138 and a grant from March of Dimes Birth Defects Foundation to M.B.-F and HD25620 to S.V.B.

Additional details

Created:
August 20, 2023
Modified:
October 18, 2023