[Induction phenomena during vertebrate limb development and homeo box gene expression].
In tetrapod vertebrates, limbs are formed as a result of inductive interactions between ectoderm and mesoderm. The mesoderm from the limb field induces the formation, in the ectoderm, of a pseudo-stratified epithelium, the apical ectodermal ridge, which in turn is required for limb mesoderm outgrowth and patterning. Homeobox genes from the msh family are expressed in the apical region of limb bud mesoderm. Using the potential of chick experimental embryology, we have demonstrated that these genes respond to ecto-mesodermal induction at this site and may be implicated in the response of the mesoderm to the ectodermal inductive activity. This property appears to be more general for the sites in the embryo which grow and are patterned as a result of interactions between ectoderm and subjacent mesoderm, since many of them are places for the expression of the msh-related genes (e.g. fronto-nasal and maxillary processes, tooth germ, genital tubercle). These genes might be implicated in patterning events at these sites through the activation of other genes directly involved in the definition of positional information, such as Hox genes.
Robert
B
B
Institut Pasteur, Paris, France.
Lyons
G
G
Krabbenhoft
K
K
Simandl
B K
BK
Houzelstein
D
D
Fallon
J
J
Buckingham
M
M
D000595:Amino Acid Sequence; D000818:Animals; D051943:Antennapedia Homeodomain Protein; D002645:Chickens / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000502:physiology; D004330:Drosophila / Q000196:embryology / Q000235:genetics; D029721:Drosophila Proteins; D004475:Ectoderm / Q000502:physiology / Q000637:transplantation; D004627:Embryonic Induction / Q000235:genetics*; D005121:Extremities / Q000196:embryology*; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D018398:Homeodomain Proteins; D008648:Mesoderm / Q000502:physiology; D051379:Mice / Q000196:embryology / Q000235:genetics; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics; D009687:Nuclear Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors; D014714:Vertebrates / Q000196:embryology* / Q000235:genetics
D051943:Antennapedia Homeodomain Protein; C497974:Antp protein, Drosophila; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors
Phénomènes d'induction dans la formation des membres chez les vertébrés et expression de gènes à homéoboîte.