Zebrafish wnt8 Encodes Two Wnt8 Proteins on a Bicistronic Transcript and Is Required for Mesoderm and Neurectoderm Patterning

• Published in: Developmental cell 2001-07, Vol.1 (1), p.103-114
• Main Authors: Lekven, Arne C., Thorpe, Christopher J., Waxman, Joshua S., Moon, Randall T.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Body Patterning - physiology; Cytoskeletal Proteins; Danio rerio; Ectoderm - physiology; Fetal Proteins; Gene Expression Regulation, Developmental; Head - embryology; Mesoderm - physiology; Molecular Sequence Data; Mutagenesis - physiology; ntl gene; Oligonucleotides, Antisense; Open Reading Frames; Phenotype; Proteins - genetics; RNA, Messenger - genetics; spt gene; T-Box Domain Proteins - genetics; Tail - embryology; Transcription, Genetic - physiology; Wnt Proteins; wnt8 gene; Zebrafish - embryology; Zebrafish Proteins - genetics
• ISSN: 1534-5807; 1878-1551
• DOI: 10.1016/S1534-5807(01)00007-7

In vertebrates, wnt8 has been implicated in the early patterning of the mesoderm. To determine directly the embryonic requirements for wnt8, we generated a chromosomal deficiency in zebrafish that removes the bicistronic wnt8 locus. We report that homozygous mutants exhibit pronounced defects in dorso-ventral mesoderm patterning and in the antero-posterior neural pattern. Despite differences in their signaling activities, either coding region of the bicistronic RNA can rescue the deficiency phenotype. Specific interference of wnt8 translation by morpholino antisense oligomers phenocopies the deficiency, and interference with wnt8 translation in ntl and spt mutants produces embryos lacking trunk and tail. These data demonstrate that the zebrafish wnt8 locus is required during gastrulation to pattern both the mesoderm and the neural ectoderm properly.