cyclops Encodes a Nodal-Related Factor Involved in Midline Signaling

• Published in: Proceedings of the National Academy of Sciences - PNAS 1998-08, Vol.95 (17), p.9932-9937
• Main Authors: Rebagliati, Michael R., Toyama, Reiko, Haffter, Pascal, Dawid, Igor B.
• Format: Article
• Language: English
• Subjects: Alleles; Amino Acid Sequence; Animals; Base Sequence; Biological Sciences; Body Patterning - genetics; Central nervous system; Central Nervous System - embryology; Cyclopes; Danio rerio; DNA; DNA Primers - genetics; DNA, Complementary - genetics; Embryonic structures; Embryos; Eye Abnormalities - embryology; Eye Abnormalities - genetics; Fish; Freshwater; Gene Expression Regulation, Developmental; Genetic mutation; Molecular Sequence Data; Mutation; Nervous system; Nodal Signaling Ligands; Phenotype; Phenotypes; Polymerase chain reaction; Prenatal development; Proteins; RNA; Signal Transduction - physiology; Transforming Growth Factor beta - genetics; Transforming Growth Factor beta - physiology; Zebrafish - embryology; Zebrafish - genetics; Zebrafish - physiology; Zebrafish Proteins
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.95.17.9932

Ventral structures in the central nervous system are patterned by signals emanating from the underlying mesoderm as well as originating within the neuroectoderm. Mutations in the zebrafish, Danio rerio, are proving instrumental in dissecting these midline signals. The cyclops mutation leads to a loss of medial floor plate and to severe deficits in ventral forebrain development, leading to cyclopia. Here, we report that the cyclops locus encodes the nodal-related protein Ndr2, a member of the transforming growth factor type β superfamily of factors. The evidence includes identification of a missense mutation in the initiation codon and rescue of the cyclops phenotype by expression of ndr2 RNA, here renamed ``cyclops.'' Thus, in interaction with other molecules implicated in these processes such as sonic hedgehog and one-eyed-pinhead, cyclops is required for ventral midline patterning of the embryonic central nervous system.