Back to Search
Start Over
Six1 and Six4 homeoproteins are required for Pax3 and Mrf expression during myogenesis in the mouse embryo.
- Source :
-
Development (Cambridge, England) [Development] 2005 May; Vol. 132 (9), pp. 2235-49. Date of Electronic Publication: 2005 Mar 23. - Publication Year :
- 2005
-
Abstract
- In mammals, Six5, Six4 and Six1 genes are co-expressed during mouse myogenesis. Six4 and Six5 single knockout (KO) mice have no developmental defects, while Six1 KO mice die at birth and show multiple organ developmental defects. We have generated Six1Six4 double KO mice and show an aggravation of the phenotype previously reported for the single Six1 KO. Six1Six4 double KO mice are characterized by severe craniofacial and rib defects, and general muscle hypoplasia. At the limb bud level, Six1 and Six4 homeogenes control early steps of myogenic cell delamination and migration from the somite through the control of Pax3 gene expression. Impaired in their migratory pathway, cells of the somitic ventrolateral dermomyotome are rerouted, lose their identity and die by apoptosis. At the interlimb level, epaxial Met expression is abolished, while it is preserved in Pax3-deficient embryos. Within the myotome, absence of Six1 and Six4 impairs the expression of the myogenic regulatory factors myogenin and Myod1, and Mrf4 expression becomes undetectable. Myf5 expression is correctly initiated but becomes restricted to the caudal region of each somite. Early syndetomal expression of scleraxis is reduced in the Six1Six4 embryo, while the myotomal expression of Fgfr4 and Fgf8 but not Fgf4 and Fgf6 is maintained. These results highlight the different roles played by Six proteins during skeletal myogenesis.
- Subjects :
- Animals
Apoptosis physiology
Bone and Bones abnormalities
DNA-Binding Proteins metabolism
Homeodomain Proteins genetics
Mice
Muscle Proteins metabolism
Muscles abnormalities
Muscles embryology
Myogenic Regulatory Factor 5
Myogenic Regulatory Factors metabolism
Myogenin
PAX3 Transcription Factor
Paired Box Transcription Factors
Trans-Activators deficiency
Transcription Factors metabolism
DNA-Binding Proteins genetics
Homeodomain Proteins metabolism
Muscle Development physiology
Muscle Proteins genetics
Myogenic Regulatory Factors genetics
Trans-Activators genetics
Trans-Activators metabolism
Transcription Factors genetics
Subjects
Details
- Language :
- English
- ISSN :
- 0950-1991
- Volume :
- 132
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- Development (Cambridge, England)
- Publication Type :
- Academic Journal
- Accession number :
- 15788460
- Full Text :
- https://doi.org/10.1242/dev.01773