Homeotic transformation of the occipital bones of the skull by ectopic expression of a homeobox gene.
Murine Hox genes have been postulated to play a role in patterning of the embryonic body plan. Gene disruption studies have suggested that for a given Hox complex, patterning of cell identity along the antero-posterior axis is directed by the more 'posterior' (having a more posterior rostral boundary of expression) Hox proteins expressed in a given cell. This supports the 'posterior prevalence' model, which also predicts that ectopic expression of a given Hox gene would result in altered structure only in regions anterior to its normal domain of expression. To test this model further, we have expressed the Hox-4.2 gene more rostrally than its normal mesoderm anterior boundary of expression, which is at the level of the first cervical somites. This ectopic expression results in a homeotic transformation of the occipital bones towards a more posterior phenotype into structures that resemble cervical vertebrae, whereas it has no effect in regions that normally express Hox-4.2. These results are similar to the homeotic posteriorization phenomenon generated in Drosophila by ectopic expression of genes of the homeotic complex HOM-C (refs 7-10; reviewed in ref. 3).
Laboratoire de Génétique Moléculaire des Eucaryotes du CNRS, Institut de Chimie Biologique, Faculté de Medecine, Strasbourg, France.
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Lufkin
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Mark
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Hart
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Dollé
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LeMeur
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Chambon
D000818:Animals; D000831:Animals, Newborn; D016375:Antisense Elements (Genetics); D001483:Base Sequence; D001921:Brain / Q000033:anatomy & histology / Q000196:embryology*; D003001:Cloning, Molecular; D000013:Congenital Abnormalities; D004247:DNA / Q000235:genetics; D004622:Embryo, Mammalian; D005801:Genes, Homeobox; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D011401:Promoter Regions, Genetic; D012886:Skull / Q000033:anatomy & histology* / Q000196:embryology; D014158:Transcription, Genetic; D014162:Transfection; D014170:Transformation, Genetic
D016375:Antisense Elements (Genetics); D009838:Oligodeoxyribonucleotides; D004247:DNA