PUBLICATION
Hypomorphic Mesp allele distinguishes establishment of rostrocaudal polarity and segment border formation in somitogenesis
- Authors
- Nomura-Kitabayashi, A., Takahashi, Y., Kitajima, S., Inoue, T., Takeda, H., and Saga, Y.
- ID
- ZDB-PUB-020514-9
- Date
- 2002
- Source
- Development (Cambridge, England) 129(10): 2473-2481 (Journal)
- Registered Authors
- Takeda, Hiroyuki
- Keywords
- somitogenesis; Mesp2; mespb; rostrocaudal polarity; segment border; resegmentation; mouse; zebrafish
- MeSH Terms
-
- Fetal Proteins/genetics
- Somites*
- Spinal Cord/abnormalities
- Glycosyltransferases/genetics
- Sequence Homology, Amino Acid
- Gene Expression Regulation, Developmental*
- Gene Dosage
- Receptor Protein-Tyrosine Kinases/genetics
- Intracellular Signaling Peptides and Proteins
- Homeodomain Proteins/genetics
- Molecular Sequence Data
- Amino Acid Sequence
- Membrane Proteins/genetics
- Zebrafish Proteins*
- Animals
- Mice, Mutant Strains
- Cadherins/genetics
- Body Patterning/genetics*
- Transcription Factors/genetics*
- Transcription Factors/metabolism
- Basic Helix-Loop-Helix Transcription Factors
- Female
- Genetic Complementation Test
- Mice
- Receptor, EphA4
- Zebrafish/genetics
- PubMed
- 11973278 Full text @ Development
Citation
Nomura-Kitabayashi, A., Takahashi, Y., Kitajima, S., Inoue, T., Takeda, H., and Saga, Y. (2002) Hypomorphic Mesp allele distinguishes establishment of rostrocaudal polarity and segment border formation in somitogenesis. Development (Cambridge, England). 129(10):2473-2481.
Abstract
A bHLH-type transcription factor, Mesp2, plays an essential role in somite segmentation in mice. Zebrafish mespb (mesp-b), a putative homologue of mouse Mesp2, is transiently expressed in the rostral presomitic mesoderm similarly to Mesp2. To determine whether zebrafish mespb is a functional homologue of mouse Mesp2, zebrafish mespb was introduced into the mouse Mesp2 locus by homologous recombination. Introduced mespb almost rescued the Mesp2 deficiency in the homozygous mespb knockin mouse, indicating that mespb is a functional homologue of mouse Mesp2. Segmented somites were clearly observed although the partial fusion of the vertebral columns still occurred. Interestingly, however, the nature and dosage of the mespb gene affected the rescue event. A mouse line, which has a hypomorphic Mesp2 allele generated by the introduction of neo-mespb, gave rise to an epithelial somite without normal rostrocaudal (RC) polarity. RC polarity was also lacking in the presomitic mesoderm. The defects in RC polarity were determined by the altered expressions of Uncx4.1 and Dll1 in the segmented somites and presomitic mesoderm, respectively. In contrast, the expression of EphA4 (Epha4), lunatic fringe or protocadherin, thought to be involved in segment border formation, was fairly normal in hypomorphic mutant embryos. These results suggest that the Mesp family of transcription factors is involved in both segment border formation and establishment of RC polarity through different genetic cascades.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping