title: Identification and Characterization of a cis-Regulatory Element for Zygotic Gene Expression in Chlamydomonas reinhardtii.
abstract: Upon fertilization Chlamydomonas reinhardtii zygotes undergo a program of differentiation into a diploid zygospore that is accompanied by transcription of hundreds of zygote-specific genes. We identified a distinct sequence motif we term a zygotic response element (ZYRE) that is highly enriched in promoter regions of C reinhardtii early zygotic genes. A luciferase reporter assay was used to show that native ZYRE motifs within the promoter of zygotic gene ZYS3 or intron of zygotic gene DMT4 are necessary for zygotic induction. A synthetic luciferase reporter with a minimal promoter was used to show that ZYRE motifs introduced upstream are sufficient to confer zygotic upregulation, and that ZYRE-controlled zygotic transcription is dependent on the homeodomain transcription factor GSP1. We predict that ZYRE motifs will correspond to binding sites for the homeodomain proteins GSP1-GSM1 that heterodimerize and activate zygotic gene expression in early zygotes.
authors.affiliation: Donald Danforth Plant Science Center, St. Louis, Missouri 63132.
authors.forename: Takashi
authors.identifier: 0000-0002-2801-2148
authors.initials: T
authors.lastname: Hamaji
authors.affiliation: Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095.
authors.forename: David
authors.identifier: 0000-0001-9363-9329
authors.initials: D
authors.lastname: Lopez
authors.affiliation: Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095.
authors.forename: Matteo
authors.identifier: 0000-0001-9355-9564
authors.initials: M
authors.lastname: Pellegrini
authors.affiliation: Donald Danforth Plant Science Center, St. Louis, Missouri 63132 JUmen@danforthcenter.org.
authors.forename: James
authors.identifier: 0000-0003-4094-9045
authors.initials: J
authors.lastname: Umen
mesh_terms: D001483:Base Sequence; D016825:Chlamydomonas reinhardtii / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D059372:Nucleotide Motifs; D056510:Position-Specific Scoring Matrices; D011401:Promoter Regions, Genetic; D055503:Protein Multimerization; D012045:Regulatory Sequences, Nucleic Acid; D015053:Zygote / Q000378:metabolism*
chemical_list: D018398:Homeodomain Proteins
keywords: Chlamydomonas; cis-regulatory element; fertilization; homeodomain protein; zygote