PUBLICATION
The midline, oral ectoderm, and the arch-0 problem
- Authors
- Kimmel, C.B., and Eberhart, J.K.
- ID
- ZDB-PUB-080825-8
- Date
- 2008
- Source
- Integrative and Comparative Biology 48(5): 668-680 (Journal)
- Registered Authors
- Eberhart, Johann, Kimmel, Charles B.
- Keywords
- none
- MeSH Terms
- none
- PubMed
- none Full text @ Integr. Comp. Biol.
Citation
Kimmel, C.B., and Eberhart, J.K. (2008) The midline, oral ectoderm, and the arch-0 problem. Integrative and Comparative Biology. 48(5):668-680.
Abstract
In most versions of theories of the segmentation of the vertebrate head, a premandibular segment is present rostral to the jaw-forming mandibular segment. These theories posit that in ancient fishes this segment included a gill and a gill-supporting skeleton, which then was modified to support the anterior brain. However, we find no recent evidence for existence of such a premandibular segment. Rather, new findings from studies of fate mapping and gene expression show that the "premandibular" territory is in fact the maxillary region of the mandibular arch. A signaling cascade, beginning with dorsal midline mesoderm in the gastrula and relayed through neural ectoderm and then oral ectoderm, greatly expands the skeletal derivatives of maxillary neural crest in a manner fully consistent with the Gans–Northcutt theory of the vertebrate new head.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping