title: Visualization of ecdysteroid activity using a reporter gene in the crustacean, Daphnia.
abstract: Ecdysone is a hormone known to play a pivotal role in crustaceans and insects. In order to evaluate the ecdysone activities in the environment and within the organism, we have developed a biomonitoring Daphnia strain by introducing a reporter gene. In this study, the ecdysone response element was inserted in the upstream region of a reporter gene, and the DNA construct was injected into Daphnia eggs. The expression of the reporter gene was detected during the early embryonic development stage. In addition, when the eggs expressing the reporter gene were exposed to ecdysone, there was enhanced expression of the reporter gene at detectable levels, while the presence of an antagonist led to its downregulation. These results suggested that this system could be potentially developed for monitoring ecdysone activities in media.
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. Electronic address: miki_asada@bio.eng.osaka-u.ac.jp.
authors.forename: Miki
authors.initials: M
authors.lastname: Asada
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. Electronic address: kato_yasuhiko@bio.eng.osaka-u.ac.jp.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. Electronic address: matsuura_tomoaki@bio.eng.osaka-u.ac.jp.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Matsuura
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. Electronic address: watanabe@bio.eng.osaka-u.ac.jp.
authors.forename: Hajime
authors.initials: H
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D003621:Daphnia / Q000196:embryology / Q000235:genetics*; D004625:Embryo, Nonmammalian; D004784:Environmental Monitoring; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D011987:Receptors, Steroid / Q000235:genetics* / Q000378:metabolism*; D020218:Response Elements / Q000235:genetics; D015053:Zygote
chemical_list: D011987:Receptors, Steroid; C055469:ecdysone receptor; D049452:Green Fluorescent Proteins
keywords: Biomonitoring; Daphnia; Ecdysone; Environmental impact; Genetics; Hormone