MBE Advance Access originally published online on February 27, 2008
Molecular Biology and Evolution 2008 25(5):912-928; doi:10.1093/molbev/msn038
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Research Articles |
Conserved Features and Evolutionary Shifts of the EDA Signaling Pathway Involved in Vertebrate Skin Appendage Development
* Molecular Zoology Team, Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Institut Fédératif Biosciences 128 Gerland Lyon Sud, CNRS, INRA, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon cedex 07, France
Cemagref, Laboratoire d'écotoxicologie, 3bis quai Chauveau, CP 220, Lyon, France
Institut des Sciences de l'Evolution de Montpellier, Unité Mixte de Recherche 5554 du Centre National pour la Recherche Scientifique, Paléontologie, Paléobiologie, and Phylogénie, cc064, Université Montpellier II, Place E. Bataillon, Montpellier, France
E-mail: vincent.laudet{at}ens-lyon.fr; sophie.pantalacci{at}ens-lyon.fr.
Accepted for publication January 31, 2008.
It is widely accepted that evolutionary changes in conserved developmental signaling pathways play an important role in morphological evolution. However, few in silico studies were interested in tracking such changes in a signaling pathway. The Ectodysplasin (EDA) pathway provides an opportunity to fill this gap because it is involved in vertebrate skin appendage development such as scales, teeth, hair, and feathers that take an obvious part in the adaptation of species to their environment. We benefited from the large amount of genomic data now available to explore the evolution of the upstream genes of the EDA pathway. In mammals, these genes are eda (encoding 2 ligands, EDA-A1 and EDA-A2), edar (EDA-A1 receptor), edaradd (EDA receptor [EDAR] adapter), xedar (EDA-A2 receptor), and troy (a XEDAR-related receptor). We show that the evolution of EDA pathway genes combines both strongly conserved features and evolutionary shifts. These shifts are found at different signaling levels (from the ligand to intracellular signaling) and at different taxonomic levels (class, suborder, and genera). Although conserved features likely participate to the similarities found in the early development of vertebrate skin appendages, these shifts might account for innovations and specializations. Moreover, our study demonstrates that we can now benefit from the large number of sequenced vertebrate genomes to explore the evolution of specific signaling pathways and thereby to open new perspectives for developmental biology and evolutionary developmental biology.
Key Words: signaling pathway • comparative genomics • EDA • Ectodysplasin • evolutionary developmental biology • skin appendages
William Jeffery, Associate Editor