title: Autoregulatory loop and retinoic acid repression regulate pou2/pou5f1 gene expression in the zebrafish embryonic brain.
abstract: Zebrafish pou5f1, also known as pou2, encodes a POU-family transcription factor that is transiently expressed in the prospective midbrain and anterior hindbrain during gastrulation, governing brain development. In the present study, we found that the main regulatory elements reside in the proximal upstream DNA sequence from -2.2 to -0.12 kb (the -2.2/-0.1 region). The electrophoretic gel mobility shift assay (EMSA) revealed four functional octamer sequences that can associate with zebrafish Pou2/Pou5f1. The expression of mutated reporter constructs, as well as EMSA, suggested that these four octamer sequences operate in a cooperative manner to drive expression in the mid/hindbrain. We also identified a retinoic acid (RA)-responsive element in this proximal region, which was required to repress transcription in the posterior part of the embryo. These data provide a scheme wherein pou2/pou5f1 expression in zebrafish embryos is regulated by both an autoregulatory loop and repression by RA emanating from the posterior mesoderm.
authors.affiliation: Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
authors.forename: Mst Shahnaj
authors.initials: MS
authors.lastname: Parvin
authors.forename: Noriko
authors.initials: N
authors.lastname: Okuyama
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Inoue
authors.forename: Md Ekramul
authors.initials: ME
authors.lastname: Islam
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawakami
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takeda
authors.forename: Kyo
authors.initials: K
authors.lastname: Yamasu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D008648:Mesoderm / Q000166:cytology / Q000502:physiology; D008969:Molecular Sequence Data; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism*; D012045:Regulatory Sequences, Nucleic Acid; D016415:Sequence Alignment; D014158:Transcription, Genetic; D014212:Tretinoin / Q000378:metabolism*; D015027:Zebrafish / Q000033:anatomy & histology / Q000196:embryology* / Q000235:genetics; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D050814:Octamer Transcription Factor-3; C085437:Pou5f3 protein, zebrafish; D029961:Zebrafish Proteins; D014212:Tretinoin