title: Dynamic changes in the gene expression of zebrafish Reelin receptors during embryogenesis and hatching period.
abstract: The brain morphology of vertebrates exhibits huge evolutionary diversity, but one of the shared morphological features unique to vertebrate brain is laminar organization of neurons. Because the Reelin signal plays important roles in the development of the laminar structures in mammalian brain, investigation of Reelin signal in lower vertebrates will give some insights into evolution of vertebrate brain morphogenesis. Although zebrafish homologues of Reelin, the ligand, and Dab1, a cytoplasmic component of the signaling pathway, have been reported, the Reelin receptor molecules of zebrafish are not reported yet. Here, we sought cDNA sequence of zebrafish homologue of the receptors, vldlr and apoer2, and examined their expression patterns by in situ hybridization. Developmental gene expression pattern of reelin, dab1, vldlr, and apoer2 in the central nervous system of zebrafish was compared, and their remarkable expression was detected in the developing laminar structures, such as the tectum and the cerebellum, and also non-laminated structures, such as the pallium. The Reelin receptors exhibited different spatial and temporal gene expression. These results suggest a possibility that duplication and subsequent functional diversity of Reelin receptors contributed to the morphological and functional evolution of vertebrate brain.
authors.affiliation: Division of Anatomy and Neurobiology, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Imai
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Oomiya
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kikkawa
authors.forename: Wataru
authors.initials: W
authors.lastname: Shoji
authors.forename: Masahiko
authors.initials: M
authors.lastname: Hibi
authors.forename: Toshio
authors.initials: T
authors.lastname: Terashima
authors.forename: Yu
authors.initials: Y
authors.lastname: Katsuyama
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000196:embryology / Q000378:metabolism; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology* / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D011956:Receptors, Cell Surface; D029961:Zebrafish Proteins; C548798:dab1a protein, zebrafish; C469363:reelin receptor