Hagfish and lancelet fibrillar collagens reveal that type II collagen-based cartilage evolved in stem vertebrates.

ABSTRACT: The origin of vertebrates was defined by evolution of a skeleton; however, little is known about the developmental mechanisms responsible for this landmark evolutionary innovation. In jawed vertebrates, cartilage matrix consists predominantly of type II collagen (Col2alpha1), whereas that of jawless fishes has long been thought to be noncollagenous. We recently showed that Col2alpha1 is present in lamprey cartilage, indicating that type II collagen-based cartilage evolved earlier than previously recognized. Here, we investigate the origin of vertebrate cartilage, and we report that hagfishes, the sister group to lampreys, also have Col2alpha1-based cartilage, suggesting its presence in the common ancestor of crown-group vertebrates. We go on to show that lancelets, a sister group to verteb

SUBMITTER: Zhang G 

PROVIDER: S-EPMC1636540 | biostudies-literature | 2006 Nov

REPOSITORIES: biostudies-literature