The transcription factor Pitx2 mediates situs-specific morphogenesis in response to left-right asymmetric signals.
The mechanism by which asymmetric signals induce left-right-specific morphogenesis has been elusive. Pitx2 encodes a transcription factor expressed throughout the left lateral plate mesoderm and subsequently on the left side of asymmetric organs such as the heart and gut during organogenesis in the chick embryo. Pitx2 is induced by the asymmetric signals encoded by Nodal and Sonic hedgehog, and its expression is blocked by prior treatment with an antibody against Sonic hedgehog. Misexpression of Pitx2 on the right side of the embryo is sufficient to produce reversed heart looping and heart isomerisms, reversed body rotation, and reversed gut situs.
Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
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Logan
S M
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Pagán-Westphal
D M
DM
Smith
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L
Paganessi
C J
CJ
Tabin
D000595:Amino Acid Sequence; D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D002642:Chick Embryo; D004064:Digestive System / Q000196:embryology; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox / Q000502:physiology; D006321:Heart / Q000196:embryology; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000502:physiology*; D006801:Humans; D008648:Mesoderm / Q000378:metabolism / Q000502:physiology; D051379:Mice; D008969:Molecular Sequence Data; D055457:Nodal Protein; D009687:Nuclear Proteins; D051761:Paired Box Transcription Factors; D011506:Proteins / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics*; D015534:Trans-Activators; D014157:Transcription Factors / Q000096:biosynthesis / Q000502:physiology*; D016212:Transforming Growth Factor beta; D000097577:Homeobox Protein PITX2
D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D055457:Nodal Protein; D009687:Nuclear Proteins; D051761:Paired Box Transcription Factors; D011506:Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D000097577:Homeobox Protein PITX2; C526007:NODAL protein, human; C526008:Nodal protein, mouse; C509239:SHH protein, human; C101485:homeobox protein PITX1; C433629:homeobox protein PITX3