Production of Wnt4b by floor plate cells is essential for the segmental patterning of the vertebral column in medaka.
The floor plate is a key organizer that controls the specification of neurons in the central nervous system. Here, we show a new role of the floor plate: segmental pattern formation of the vertebral column. Analysis of a spontaneous medaka mutant, fused centrum (fsc), which exhibits fused centra and the absence of the intervertebral ligaments, revealed that fsc encodes wnt4b, which was expressed exclusively in the floor plate. In fsc mutants, we found that wnt4b expression was completely lost in the floor plate and that abnormal conversion of the intervertebral ligament cells into osteoblasts appeared to cause a defect of the intervertebral ligaments. The establishment of the transgenic rescue lines and mosaic analyses allowed the conclusion to be drawn that production of wnt4b by floor plate cells is essential for the segmental patterning of the vertebral column. Our findings provide a novel perspective on the mechanism of vertebrate development.
Inohaya
Keiji
K
Department of Biological Information, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8501, Japan.
Takano
Yoshiro
Y
Kudo
Akira
A
D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D019521:Body Patterning / Q000235:genetics / Q000502:physiology; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D029941:Fish Proteins / Q000096:biosynthesis* / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D054259:Neural Tube / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D009990:Oryzias / Q000196:embryology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D010641:Phenotype; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013131:Spine / Q000196:embryology* / Q000254:growth & development / Q000378:metabolism*; D051153:Wnt Proteins / Q000096:biosynthesis* / Q000235:genetics
D017931:DNA Primers; D029941:Fish Proteins; D011993:Recombinant Fusion Proteins; D051153:Wnt Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins