title: Regulatory mechanisms of ecdysone-inducible Blimp-1 encoding a transcriptional repressor that is important for the prepupal development in Drosophila.
abstract: Blimp-1 is an ecdysone-inducible transcription factor that is expressed in the early stage of the prepupal period. The timing of its disappearance determines expression timing of the FTZ-F1 gene, whose temporally restricted expression is essential for the prepupal development. To elucidate the termination mechanism of Blimp-1 gene expression, we examined the regulation of the Blimp-1 gene using an organ culture system. The results showed that the Blimp-1 gene is transcribed in cultured organs taken from a low ecdysteroid period even after extended exposure to 20-hydroxyecdysone, while well-known early genes such as E75A are repressed under the same conditions. Similar selective transcription was observed in the cultured organs obtained from a high ecdysteroid period. We further showed that Blimp-1 transcripts quickly disappeared in the presence of actinomycin D. From these results, we concluded that the Blimp-1 gene is transcribed when the ecdysteroid titer is high, but the expressed mRNA degrades rapidly; these unique regulations limit its expression to the high ecdysteroid stage.
authors.affiliation: The Graduate School of Natural Science and Technology and Department of Biology, Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Okayama 700-8530, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Akagi
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ueda
mesh_terms: D000818:Animals; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D003609:Dactinomycin; D004330:Drosophila / Q000254:growth & development*; D029721:Drosophila Proteins / Q000378:metabolism*; D004440:Ecdysone / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D007814:Larva / Q000254:growth & development; D012097:Repressor Proteins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000378:metabolism
chemical_list: C525044:Blimp-1 protein, Drosophila; D017931:DNA Primers; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C499712:nuclear hormone receptor FTZ-F1, Drosophila; D003609:Dactinomycin; D004440:Ecdysone