The role of Otx and Otp genes in brain development.
Over the last ten years, many genes involved in the induction, specification and regionalization of the brain have been identified and characterized at the functional level through a series of animal models. Among these genes, both Otx1 and Otx2, two murine homologues of the Drosophila orthodenticle (otd) gene which encode transcription factors, play a pivotal role in the morphogenesis of the rostral brain. Classical knock-out studies have revealed that Otx2 is fundamental for the early specification and subsequent maintenance of the anterior neural plate, whereas Otx1 is mainly necessary for both normal corticogenesis and sense organ development. A minimal threshold of both gene products is required for correct patterning of the fore-midbrain and positioning of the isthmic organizer. A third gene, Orthopedia (Otp) is a key element of the genetic pathway controlling development of the neuroendocrine hypothalamus. This review deals with a comprehensive analysis of the Otx1, Otx2 and Otp functions, and with the possible evolutionary implications suggested by the models in which the Otx genes are reciprocally replaced or substituted by the Drosophila homologue, otd.
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International Institute of Genetics and Biophysics, Naples, Italy.
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Avantaggiato
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Di Bonito
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Simeone
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D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D001921:Brain / Q000196:embryology* / Q000378:metabolism*; D002490:Central Nervous System / Q000196:embryology; D004330:Drosophila / Q000196:embryology; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D051379:Mice; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D008957:Models, Genetic; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000502:physiology*; D051857:Otx Transcription Factors; D050809:POU Domain Factors; D010641:Phenotype; D012097:Repressor Proteins / Q000096:biosynthesis / Q000502:physiology; D012679:Sense Organs / Q000196:embryology; D015534:Trans-Activators / Q000096:biosynthesis* / Q000502:physiology*; D014157:Transcription Factors / Q000096:biosynthesis
D051792:Basic Helix-Loop-Helix Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D051857:Otx Transcription Factors; D050809:POU Domain Factors; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C088624:Otp protein, mouse; C497656:Otx1 protein, mouse; C497660:Otx2 protein, mouse; C101750:Sim1 protein, mouse; C490260:otp protein, Drosophila; C085076:transcription factor Brn-2