Natural mixtures of persistent organic pollutants (POP) increase weight gain, advance puberty, and induce changes in gene expression associated with steroid hormones and obesity in female zebrafish.
In the present study, developmental and reproductive effects of lifelong exposure to environmental relevant concentrations of two natural mixtures of persistent organic pollutants (POP) were investigated using classical and molecular methods in a controlled zebrafish model. The mixtures used were extracted from burbot (Lota lota) liver originating from freshwater systems in Norway: one mixture with high levels and one mixture with background levels of polybrominated diphenyl ethers (PBDE), polychlorinated biphenyls (PCB), and dichlorodiphenyltrichloroethane metabolites (DDT). The concentration of POP measured in the zebrafish ranged from levels detected in wild fish from Lake Mjøsa to concentrations reported in human and wildlife populations, indicating that the experimental fish were exposed to concentrations comparable with wild fish. Phenotypic effects observed in both exposure groups included earlier onset of puberty, increased male/female sex ratio, and differences in body weight at 5 mo of age. Interestingly, genome-wide transcription profiling showed changes in regulation of genes involved in endocrine signaling and growth. The transcriptomics changes include key regulator genes for steroid hormone functions (ncoa3), and growth (c/ebp, ncoa3). The effects observed in the experimental zebrafish model raise the question whether chemical pollution represents a risk to reproductive health of wild fish inhabitating the freshwater system.
Department of Production Animal Clinical Science, Norwegian School of Veterinary Science, POB 8146 Dep., N-0033 Oslo, Norway. jan.l.lyche@veths.no
Jan L
JL
Lyche
Rasoul
R
Nourizadeh-Lillabadi
Camilla
C
Almaas
Benedicte
B
Stavik
Vidar
V
Berg
Janneche Utne
JU
Skåre
Peter
P
Alestrøm
Erik
E
Ropstad
D000818:Animals; D001156:Artemia / Q000737:chemistry; D045424:Complex Mixtures / Q000032:analysis / Q000633:toxicity*; D003634:DDT / Q000032:analysis / Q000633:toxicity; D005260:Female; D005618:Fresh Water; D015870:Gene Expression / Q000187:drug effects*; D020869:Gene Expression Profiling; D055768:Halogenated Diphenyl Ethers / Q000032:analysis / Q000633:toxicity; D017403:In Situ Hybridization; D008099:Liver / Q000737:chemistry / Q000378:metabolism; D009765:Obesity / Q000139:chemically induced*; D020411:Oligonucleotide Array Sequence Analysis; D009930:Organic Chemicals / Q000032:analysis / Q000633:toxicity*; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000633:toxicity; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012744:Sex Ratio; D012741:Sexual Maturation / Q000187:drug effects*; D013256:Steroids / Q000096:biosynthesis*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D015430:Weight Gain / Q000187:drug effects*; D015027:Zebrafish
D045424:Complex Mixtures; D055768:Halogenated Diphenyl Ethers; D009930:Organic Chemicals; D013256:Steroids; D014874:Water Pollutants, Chemical; D012313:RNA; C086401:pentabromodiphenyl ether; D003634:DDT; D011078:Polychlorinated Biphenyls