CiteULike CiteULike
Delicious Delicious
Connotea Connotea

Citation for Study 1475

About Citation title: "Evolution and Development of the Chordates: Collagen and Pharyngeal Cartilage".
About This study was previously identified under the legacy study ID S1419 (Status: Published).

Citation

Rychel A., Smith S., Shimamoto H., & Swalla B. 2005. Evolution and Development of the Chordates: Collagen and Pharyngeal Cartilage. Molecular Biology and Evolution, 23: 1-9.

Authors

  • Rychel A.
  • Smith S.
  • Shimamoto H.
  • Swalla B.

Abstract

Chordates evolved a unique body plan within deuterostomes and are considered to share five morphological characters,a muscular postanal tail, a notochord, a dorsal neural tube, an endostyle, and pharyngeal gill slits. The phylum Chordata typically includes three subphyla, Cephalochordata, Vertebrata, and Tunicata, the last showing a chordate body plan only as a larva. Hemichordates, in contrast, have pharyngeal gill slits, an endostyle, and a postanal tail but appear to lack a notochord and dorsal neural tube. Because hemichordates are the sister group of echinoderms, the morphological features shared with the chordates must have been present in the deuterostome ancestor. No extant echinoderms share any of the chordate features, so presumably they have lost these structures evolutionarily. We review the development of chordate characters in hemichordates and present new data characterizing the pharyngeal gill slits and their cartilaginous gill bars. We show that hemichordate gill bars contain collagen and proteoglycans but are acellular. Hemichordates and cephalochordates, or lancelets, show strong similarities in their gill bars, suggesting that an acellular cartilage may have preceded cellular cartilage in deuterostomes. Our evidence suggests that the deuterostome ancestor was a benthic worm with gill slits and acellular gill cartilages.

External links

About this resource

  • Canonical resource URI: http://purl.org/phylo/treebase/phylows/study/TB2:S1475
  • Other versions: Download Reconstructed NEXUS File Nexus Download NeXML File NeXML
  • Show BibTeX reference
  • Show RIS reference