The vertebrate segmentation clock
- Giudicelli, F., and Lewis, J.
- Current opinion in genetics & development 14(4): 407-414 (Review)
- Registered Authors
- Lewis, Julian
- bHLH, basic helix-loop-helix; E(spl), Enhancer of split; her, hairy/E(spl)-related gene; Hes, hairy/E(spl) gene homologue, Lfng, Lunatic fringe, PSM, presomitic mesoderm
- MeSH Terms
- Axin Protein
- Basic Helix-Loop-Helix Transcription Factors
- Biological Clocks/physiology*
- Body Patterning/physiology*
- Cytoskeletal Proteins/metabolism
- Embryonic Development/physiology*
- Gene Expression Regulation, Developmental*
- Intercellular Signaling Peptides and Proteins/metabolism
- Membrane Proteins/metabolism
- Models, Biological*
- Receptors, Notch
- Time Factors
- Transcription Factors/metabolism
- Wnt Proteins
- 15261657 Full text @ Curr. Opin. Genet. Dev.
Giudicelli, F., and Lewis, J. (2004) The vertebrate segmentation clock. Current opinion in genetics & development. 14(4):407-414.
In vertebrate embryos, somite segmentation is controlled by a molecular clock, in the form of a transcriptional oscillator that operates in the presomitic mesoderm. Most of the genes implicated in the oscillator belong to the Notch pathway; a recently discovered exception is the Wnt pathway gene Axin2. Experiments have revealed several negative feedback loops that might generate oscillations, leading to at least four different theories. The simplest of these is based on direct autoinhibition of certain members of the hairy/E(spl) family of Notch target genes - Hes7 in the mouse, and her1 and her7 in the zebrafish. A mathematical account of this mechanism explains some surprising observations and suggests that the period of oscillation is chiefly determined by the transcriptional and translational delays - the times required to make a molecule of the mRNA and a molecule of the protein.
Genes / Markers
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Engineered Foreign Genes