Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-9-4
pubmed:abstractText
We report herein that a pentadactyl developmental pattern is evident in early wing morphogenesis of Gallus (chicken) and Struthio (ostrich). Five avascular zones (spatially predestined locations of contiguous metacarpal and phalangeal aggregation) and four interdigital vascular spaces are established by the regression patterns of autopodial vasculature. Transient vestiges of the first and fifth metacarpals are confirmed histologically and histochemically. They lie within the preaxial-most and postaxial-most avascular zones, respectively. These observations reveal conservative patterning of the avian hand and corroborate a II-III-IV metacarpal interpretation, argue for II-III-IV identity of ossified digits in birds, and favour a simple reduction rather than a homeotic shift in terms of the phenotype expressed by Hox genes in the phylogeny of the avian manus. We suggest that gradual, bilateral reduction of phalanges and metacarpals, via apoptosis mediated by BMP, occurred during the evolution of birds (Pyramid Reduction Hypothesis). This is congruent with the establishment of a central wing axis that became co-opted for coordinated movements. On the basis of evidence presented here, the direct avian ancestor is predicted to have been five-fingered with dominant digits (+ metacarpals) as follow: II, III, IV.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-104X
pubmed:author
pubmed:copyrightInfo
Copyright 2002 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
294
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
152-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Pentadactyl pattern of the avian wing autopodium and pyramid reduction hypothesis.
pubmed:affiliation
Department of Zoology, Natural Science Faculty, Charles University, Prague 2, CZ 128 44, Czech Republic. mkundrat@email.cz
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't