Frame-shifts of digit identity in bird evolution and Cyclopamine-treated wings

Vargas A.O.; Wagner G.P.

Keywords: evolution, proteins, alkaloids, cartilage, mouse, birds, animals, expression, biology, protein, gene, morphology, histology, physiology, mice, mutation, metabolism, bird, embryo, phenotype, genetics, morphogenesis, regulation, time, steroid, body, molecular, article, analysis, aves, evolutionary, animal, homeodomain, developmental, patterning, alkaloid, factors, frameshift, forelimb, cyclopamine, alligator, and, Evolution,, Regulation,, spatiotemporal, wing, Veratrum, Amniota, Alligators, Crocodiles, Archaeopteryx

Abstract

A highly conserved spatio-temporal pattern of cartilage formation reveals that the digits of the bird wing develop from positions that become digits 2, 3, and 4 in other amniotes. However, the morphology of the digits of early birds like Archaeopteryx corresponds to that of digits 1, 2, and 3 of other archosaurs. A hypothesis is that a homeotic "frame-shift" occurred, such that in the bird wing, digits 1, 2, and 3 develop from the embryological positions of digits 2, 3, and 4. Experimental homeotic transformations of single digits are well-documented, but frame-shifts of more than one digit are not. We investigated the pattern of cartilage formation in the development of Cyclopamine-treated wings. When Cyclopamine was applied between stages 18 and 21, morphologies that normally develop from positions 2 and 3 developed from positions 3 and 4. The serial shift of digit identity toward posterior confirms a mechanistic possibility that was previously inferred from the evolutionary history of birds. © 2009 The Author(s).

Más información

Título según SCOPUS: Frame-shifts of digit identity in bird evolution and Cyclopamine-treated wings
Título de la Revista: EVOLUTION & DEVELOPMENT
Volumen: 11
Número: 2
Editorial: Wiley
Fecha de publicación: 2009
Página de inicio: 163
Página final: 169
Idioma: eng
URL: http://www.scopus.com/inward/record.url?eid=2-s2.0-60849087074&partnerID=q2rCbXpz
DOI:

10.1111/j.1525-142X.2009.00317.x

Notas: SCOPUS