title: Parental exposure to natural mixtures of persistent organic pollutants (POP) induced changes in transcription of apoptosis-related genes in offspring zebrafish embryos.
abstract: Apoptosis is an integral element of development that may also be initiated by environmental contaminants. The aim of the present study was to assess potential changes in the regulation of apoptotic genes in zebrafish embryos following parental exposure to two natural mixtures of persistent organic pollutants (POP). The mixture from Lake Mjøsa contained exceptionally high concentrations of polybrominated diphenyl ethers (PBDE), as well as relatively high levels of polychlorinated biphenyls (PCB) and dichlorodiphenyltrichloroethane (DDT). The mixture from Lake Losna contained background concentrations of POP. Genes involved in the apoptotic machinery were screened for their expression profile at four time points during embryonic development. Thirteen and 15 genes involved in apoptosis were found to be significantly upregulated in the high-exposure and background exposure groups, respectively, compared with controls. Modulation of apoptotic genes was restricted only to the first time point, which corresponds with the blastula stage. Although there were substantial differences in POP concentrations between mixtures, genes underlying the apoptosis process showed almost similar responses to the two mixtures. In both exposure groups the main executors of apoptosis p53, casp 2, casp 6, cassp 8, and BAX displayed upregulation compared to controls, suggesting that these POP induce apoptosis via a p53-dependent mechanism. Upregulation of genes that play a critical role in apoptosis suggests that disturbance of normal apoptotic signaling during gametogenesis and embryogenesis may be one of the central mechanisms involved in adverse reproductive effects produced by POP in zebrafish.
authors.affiliation: a Department of Food Safety and Infection Biology , Norwegian University of Life Science , Oslo , Norway.
authors.forename: Jan L
authors.initials: JL
authors.lastname: Lyche
authors.affiliation: b Institute of Environmental Sciences , Jagiellonian Uniwersity , Kraków , Poland.|c Department of Zoology and Ecology , University of Agriculture , Kraków , Poland.
authors.forename: Irena M
authors.initials: IM
authors.lastname: Grześ
authors.affiliation: d Department of Production Animal Clinical Science , Norwegian University of Life Science , Oslo , Norway.
authors.forename: Camilla
authors.initials: C
authors.lastname: Karlsson
authors.affiliation: e Department of Basic Sciences and Aquatic Medicine , Norwegian School of Veterinary Science , Oslo , Norway.
authors.forename: Rasoul
authors.initials: R
authors.lastname: Nourizadeh-Lillabadi
authors.affiliation: e Department of Basic Sciences and Aquatic Medicine , Norwegian School of Veterinary Science , Oslo , Norway.
authors.forename: Peter
authors.initials: P
authors.lastname: Aleström
authors.affiliation: d Department of Production Animal Clinical Science , Norwegian University of Life Science , Oslo , Norway.
authors.forename: Erik
authors.initials: E
authors.lastname: Ropstad
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000196:embryology / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015027:Zebrafish / Q000196:embryology / Q000235:genetics* / Q000378:metabolism*
chemical_list: D014874:Water Pollutants, Chemical