title: Identification of the 187 bp EphA7 Genomic DNA as the Dorsal Midline-Specific Enhancer of the Diencephalon and Mesencephalon.
abstract: EphA7 is a key molecule in regulating the development of the dien- and mesencephalon. To get insight into the mechanism of how EphA7 gene expression is regulated during the dorsal specification of the dien- and mesencephalon, we investigated the cis-acting regulatory sequence driving EphA7 to the dorsal midline of the dien- and mesencephalon. Transgenic LacZ reporter analysis, using overlapping EphA7 BACs, was used to narrow down the dorsal midline-specific enhancer, revealing the 25.3 kb genomic region as the enhancer candidate. Strikingly, this genomic DNA was located far downstream of the EphA7 transcription start site, +302.6 kb to +327.9 kb. Further enhancer mapping, using comparative genomic analysis and transgenic methods, showed that the 187 bp genomic DNA alone, approximately 305 kb downstream of the EphA7 transcription start site, was sufficient to act as the dorsal midline-specific enhancer of EphA7. Importantly, our results indicate that the 187 bp dorsal midline-specific enhancer is critically regulated by homeobox transcription factors during the development of the dien- and mesencephalon.
authors.affiliation: Department of Biological Science, Sookmyung Women's University, Seoul 140-742, Korea.
authors.forename: Yujin
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Biological Science, Sookmyung Women's University, Seoul 140-742, Korea.
authors.forename: Eunjeong
authors.initials: E
authors.lastname: Park
authors.affiliation: Department of Biological Science, Sookmyung Women's University, Seoul 140-742, Korea.
authors.forename: Soochul
authors.initials: S
authors.lastname: Park
mesh_terms: D000818:Animals; D001483:Base Sequence; D002642:Chick Embryo; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D017124:Conserved Sequence; D004247:DNA / Q000235:genetics; D004027:Diencephalon / Q000196:embryology*; D004742:Enhancer Elements, Genetic / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D018398:Homeodomain Proteins / Q000378:metabolism; D008636:Mesencephalon / Q000196:embryology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D036141:Receptor, EphA7 / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000378:metabolism; D024363:Transcription Initiation Site
chemical_list: D018398:Homeodomain Proteins; D014157:Transcription Factors; D004247:DNA; D036141:Receptor, EphA7
keywords: EphA7; dorsal midline; enhancer