Developmental basis of limblessness and axial patterning in snakes

Martin J .Cohn () and Cheryll Tickle
Additional contact information
Martin J .Cohn: School of Animal and Microbial Sciences, University of Reading
Cheryll Tickle: Wellcome Trust Building, University of Dundee

Nature, 1999, vol. 399, issue 6735, 474-479

Abstract: Abstract The evolution of snakes involved major changes in vertebrate body plan organization, but the developmental basis of those changes is unknown. The python axial skeleton consists of hundreds of similar vertebrae, forelimbs are absent and hindlimbs are severely reduced. Combined limb loss and trunk elongation is found in many vertebrate taxa1, suggesting that these changes may be linked by a common developmental mechanism. Here we show that Hox gene expression domains are expanded along the body axis in python embryos, and that this can account for both the absence of forelimbs and the expansion of thoracic identity in the axial skeleton. Hindlimb buds are initiated, but apical-ridge and polarizing-region signalling pathways that are normally required for limb development are not activated. Leg bud outgrowth and signalling by Sonic hedgehog in pythons can be rescued by application of fibroblast growth factor or by recombination with chick apical ridge. The failure to activate these signalling pathways during normal python development may also stem from changes in Hox gene expression that occurred early in snake evolution.

Date: 1999
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/20944 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:399:y:1999:i:6735:d:10.1038_20944

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/20944

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().