title: Conversion of a mesodermalizing molecule, the Xenopus Brachyury gene, into a neuralizing factor.
abstract: It has been shown previously that a Xenopus homolog of the mouse gene Brachyury, Xbra, can initiate mesodermal differentiation. Here, I report that a Xbra mutant truncated at the carboxyl terminus, B304, has lost the mesodermalizing activity and can block the activity of the wild-type Xbra. Injection of B304 mRNA led to formation of neural structures in animal cap explants. Examination of molecular markers in B304-injected explants shows expression of anterior neural markers in the absence of mesodermal markers, indicating that B304 can cause neuralization without the mediation of mesoderm. Implications of these findings on intracellular mechanisms underlying the initiation of neural differentiation in the ectodermal cells are discussed.
authors.affiliation: Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.
authors.forename: Y
authors.initials: Y
authors.lastname: Rao
mesh_terms: D028341:Activins; D000818:Animals; D001483:Base Sequence; D015415:Biomarkers; D015816:Cell Adhesion Molecules, Neuronal / Q000096:biosynthesis; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005326:Fetal Proteins / Q000235:genetics / Q000378:metabolism*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D038681:Follistatin; D051858:Forkhead Transcription Factors; D006023:Glycoproteins / Q000096:biosynthesis; D007265:Inhibins / Q000494:pharmacology; D008648:Mesoderm / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D009420:Nervous System / Q000196:embryology*; D009687:Nuclear Proteins / Q000096:biosynthesis; D017384:Sequence Deletion; D013329:Structure-Activity Relationship; D020825:T-Box Domain Proteins; D014157:Transcription Factors / Q000096:biosynthesis; D014981:Xenopus / Q000196:embryology* / Q000235:genetics*; D000098908:Brachyury Protein
chemical_list: D028341:Activins; D015415:Biomarkers; D015816:Cell Adhesion Molecules, Neuronal; D004268:DNA-Binding Proteins; D005326:Fetal Proteins; D016222:Fibroblast Growth Factor 2; D038681:Follistatin; D051858:Forkhead Transcription Factors; D006023:Glycoproteins; D007265:Inhibins; D009687:Nuclear Proteins; D020825:T-Box Domain Proteins; D014157:Transcription Factors; D000098908:Brachyury Protein