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Embryonic origin of the gnathostome vertebral skeleton.

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Criswell, Katharine E  ORCID logo  https://orcid.org/0000-0002-4004-0192
Gillis, J Andrew 

Abstract

The vertebral column is a key component of the jawed vertebrate (gnathostome) body plan, but the primitive embryonic origin of this skeleton remains unclear. In tetrapods, all vertebral components (neural arches, haemal arches and centra) derive from paraxial mesoderm (somites). However, in teleost fishes, vertebrae have a dual embryonic origin, with arches derived from somites, but centra formed, in part, by secretion of bone matrix from the notochord. Here, we test the embryonic origin of the vertebral skeleton in a cartilaginous fish (the skate, Leucoraja erinacea) which serves as an outgroup to tetrapods and teleosts. We demonstrate, by cell lineage tracing, that both arches and centra are somite-derived. We find no evidence of cellular or matrix contribution from the notochord to the skate vertebral skeleton. These findings indicate that the earliest gnathostome vertebral skeleton was exclusively of somitic origin, with a notochord contribution arising secondarily in teleosts.

Description

Keywords

evolution, notochord, skate, somite, vertebrae, vertebral skeleton, Animals, Body Patterning, Notochord, Skates, Fish, Spine

Journal Title

Proc Biol Sci

Conference Name

Journal ISSN

0962-8452
1471-2954

Volume Title

284

Publisher

The Royal Society
Sponsorship
The Royal Society (uf130182)
Isaac Newton Trust (1423(z))
Royal Society (NF160762)