The genetic program for cartilage development has deep homology within Bilateria.
The evolution of novel cell types led to the emergence of new tissues and organs during the diversification of animals. The origin of the chondrocyte, the cell type that synthesizes cartilage matrix, was central to the evolution of the vertebrate endoskeleton. Cartilage-like tissues also exist outside the vertebrates, although their relationship to vertebrate cartilage is enigmatic. Here we show that protostome and deuterostome cartilage share structural and chemical properties, and that the mechanisms of cartilage development are extensively conserved--from induction of chondroprogenitor cells by Hedgehog and β-catenin signalling, to chondrocyte differentiation and matrix synthesis by SoxE and SoxD regulation of clade A fibrillar collagen (ColA) genes--suggesting that the chondrogenic gene regulatory network evolved in the common ancestor of Bilateria. These results reveal deep homology of the genetic program for cartilage development in Bilateria and suggest that activation of this ancient core chondrogenic network underlies the parallel evolution of cartilage tissues in Ecdysozoa, Lophotrochozoa and Deuterostomia.
Howard Hughes Medical Institute, UF Genetics Institute, University of Florida, PO Box 103610, Gainesville, Florida 32610, USA.|Department of Biology, University of Florida, PO Box 103610, Gainesville, Florida 32610, USA.
Oscar A
OA
Tarazona
Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, PO Box 103610, Gainesville, Florida 32610, USA.
Leslie A
LA
Slota
Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, PO Box 103610, Gainesville, Florida 32610, USA.
Davys H
DH
Lopez
Department of Biology, University of Florida, PO Box 103610, Gainesville, Florida 32610, USA.
GuangJun
G
Zhang
Howard Hughes Medical Institute, UF Genetics Institute, University of Florida, PO Box 103610, Gainesville, Florida 32610, USA.|Department of Biology, University of Florida, PO Box 103610, Gainesville, Florida 32610, USA.|Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, PO Box 103610, Gainesville, Florida 32610, USA.
Martin J
MJ
Cohn
D000818:Animals; D002356:Cartilage / Q000033:anatomy & histology / Q000196:embryology / Q000378:metabolism; D019902:Chondrocytes / Q000166:cytology; D020219:Chondrogenesis / Q000235:genetics*; D017124:Conserved Sequence / Q000235:genetics*; D049832:Decapodiformes / Q000166:cytology / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D024022:Fibrillar Collagens / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D053263:Gene Regulatory Networks; D053823:Hedgehog Proteins / Q000378:metabolism; D007448:Invertebrates / Q000166:cytology / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology; D014714:Vertebrates / Q000033:anatomy & histology / Q000235:genetics; D051176:beta Catenin / Q000378:metabolism
D024022:Fibrillar Collagens; D053823:Hedgehog Proteins; D051176:beta Catenin