title: Identification of a prosencephalic-specific enhancer of SALL1: comparative genomic approach using the chick embryo.
abstract: Comparative genomics is a promising approach for identifying regulatory elements governing the unique spatio-temporal expression patterns of morphogenetic genes. Conserved noncoding genomic sequences are candidate regulatory elements. Here we performed a survey for conserved noncoding elements (CNE) nested within the SALL1 gene; mutations in this gene result in the Townes-Brocks syndrome. A comparison of the genomic sequence between humans and chicken revealed five CNE. Genomic fragments corresponding to each CNE were inserted into reporter cassettes consisting of eGFP cDNA and a minimal promoter. These constructs were electroporated into chick embryos during gastrula, neurula, and pharyngula stages. Among the five CNE that were examined, one 443 bp CNE exhibited tissue-specific enhancer activity. At the neurula stage, the eGFP signal was visualized in the prosencephalon. At the pharyngula stage, the eGFP signal was confined within the anterior neural ridge, which represents one of the morphogenetic centers regulating the patterning of the anterior neural plate. This report identifies, for the first time, an enhancer element of SALL1.
authors.affiliation: Department of Pediatrics, Keio University School of Medicine, Tokyo 160-8582, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Izumi
authors.forename: Michihiko
authors.initials: M
authors.lastname: Aramaki
authors.forename: Tokuhiro
authors.initials: T
authors.lastname: Kimura
authors.forename: Yoko
authors.initials: Y
authors.lastname: Naito
authors.forename: Toru
authors.initials: T
authors.lastname: Udaka
authors.forename: Masanori
authors.initials: M
authors.lastname: Uchikawa
authors.forename: Hisato
authors.initials: H
authors.lastname: Kondoh
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Suzuki
authors.forename: Ginam
authors.initials: G
authors.lastname: Cho
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Okada
authors.forename: Takao
authors.initials: T
authors.lastname: Takahashi
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Golden
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Kosaki
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002642:Chick Embryo; D017124:Conserved Sequence; D047108:Embryonic Development / Q000235:genetics; D004742:Enhancer Elements, Genetic; D017930:Genes, Reporter; D023281:Genomics / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D006801:Humans; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D017384:Sequence Deletion; D014157:Transcription Factors / Q000235:genetics*
chemical_list: C104146:SALL1 protein, human; D014157:Transcription Factors; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins