Expression of brain-type fatty acid-binding protein (fabp7) in medaka during development.
Fatty acid-binding proteins (FABPs) belong to a multigene family of small intracellular proteins that bind hydrophobic ligands. Recent studies have indicated that FABP7 plays important roles in neurogenesis or neuronal migration in vertebrates. In this study, we isolated cDNA and the genomic fragment containing the fabp7 gene for medaka fish and examined the expression of the medaka fabp7 gene through the development of their central nervous system (CNS). The medaka fabp7 gene consists of four exons in approximately 1 kb of the genomic region. Its deduced amino acid sequence exhibits over 80% identity with those of other higher vertebrates. In situ hybridization analysis demonstrated that fabp7-positive cells first appear at stage 22 in a small dorsal domain of the retina, dorsal diencephalon, and rhombencephalon, then expand to the entire CNS including the retina and the spinal cord. In addition, we generated two lines of transgenic medaka with 1.7 kb upstream of the fabp7 gene combined with the enhanced-green fluorescence protein (EGFP) gene. The spatio-temporal expression patterns of EGFP in these animals were consistent with the results of in situ hybridization analysis. The result of our reporter assays with a series of truncated fabp7 promoters suggested that POU elements play a role in fabp7 expression in medaka as well as in other vertebrates. Our transgenic animal will contribute to clarifying the role of FABP7 in the development of CNS.
Environmental Radiation Effects Research Group, Research Center for Radiation Protection, Japan.
Kouichi
K
Maruyama
Ayako
A
Kojima
Takako
T
Yasuda
Katsutoshi
K
Suetomi
Yoshihisa
Y
Kubota
Sentaro
S
Takahashi
Yuji
Y
Ishikawa
Akira
A
Fujimori
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D002490:Central Nervous System / Q000196:embryology; D003001:Cloning, Molecular; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism; D050556:Fatty Acid-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D023061:Gene Order; D049452:Green Fluorescent Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D009990:Oryzias / Q000196:embryology* / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D016415:Sequence Alignment
D050556:Fatty Acid-Binding Proteins; D049452:Green Fluorescent Proteins