Zebrafish gcmb is required for pharyngeal cartilage formation.
The glial cells missing (gcm) gene in Drosophila encodes a GCM-motif transcription factor that functions as a binary switch to select between glial and neuronal cell fates. To understand the function of gcm in vertebrates, we isolated the zebrafish gcmb and analyzed the function of this gene using antisense morpholino oligonucleotides against gcmb mRNA (gcmb-MO) and transgenic overexpression. Zebrafish gcmb is expressed in the pharyngeal arch epithelium and in cells of the macrophage lineage. gcmb-MO-injected larvae show significantly reduced branchial arch cartilages. fgf3-MO-injected larvae display a similar phenotype to that of gcmb-MO-injected larvae with respect to the lack of pharyngeal cartilage formation. In addition, gcmb expression in the pharyngeal arches is down-regulated in fgf3-MO-injected larvae. The gcmb transgenic larvae show a protrusion of the lower jaw and abnormal spatial arrangement of the pharyngeal cartilage elements. These results suggest that gcmb is required for normal pharyngeal cartilage formation in zebrafish and that its expression is dependent on fgf3 activity.
Laboratory for Developmental Gene Regulation, The Institute of Physical and Chemical Research, RIKEN Brain Science Institute, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan.
Ryuki
R
Hanaoka
Yasuhiro
Y
Ohmori
Keiichi
K
Uyemura
Toshihiko
T
Hosoya
Yoshiki
Y
Hotta
Tomoaki
T
Shirao
Hitoshi
H
Okamoto
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D001934:Branchial Region / Q000254:growth & development*; D002356:Cartilage / Q000254:growth & development*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins; D051518:Fibroblast Growth Factor 3; D005346:Fibroblast Growth Factors / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D008954:Models, Biological; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000235:genetics*; D020319:Oligodeoxyribonucleotides, Antisense / Q000235:genetics / Q000494:pharmacology; D010641:Phenotype; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000235:genetics*; D014157:Transcription Factors; D015027:Zebrafish / Q000235:genetics* / Q000254:growth & development*; D029961:Zebrafish Proteins / Q000235:genetics*
D004268:DNA-Binding Proteins; D051518:Fibroblast Growth Factor 3; D009479:Neuropeptides; D020319:Oligodeoxyribonucleotides, Antisense; D015534:Trans-Activators; D014157:Transcription Factors; D029961:Zebrafish Proteins; C489200:fgf3 protein, zebrafish; C501172:gcm2 protein, zebrafish; D005346:Fibroblast Growth Factors