title: p,p'-DDE Induces Gonadal Intersex in Japanese Medaka (Oryzias latipes) at Environmentally Relevant Concentrations: Comparison with o,p'-DDT.
abstract: Previous studies have reported high body burdens of dichlorodiphenyltrichloroethane (DDT) and its metabolites in wild fishes worldwide. This study evaluated the adverse effects of 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) and o,p'-DDT on gonadal development and reproduction by exposing transgenic Japanese medaka (Oryzias latipes) from hatch for 100 days. While both p,p'-DDE and o,p'-DDT induced intersex in male medaka, the lowest observable effective concentration (LOEC) of o,p'-DDT was 57.7 ng/g ww, about 5-fold lower than that (272 ng/g ww) of p,p'-DDE. Since LOECs of both chemicals were comparable to the body concentrations in wild fish, DDT contamination would likely contribute to the occurrence of intersex observed in wild fish. Exposure to o,p'-DDT resulted in much higher expression of vitellogenin in liver of males than p,p'-DDE, accordant with the higher potency of o,p'-DDT than p,p'-DDE to induce intersex. This phenomenon could be partly explained by the significantly elevated levels of 17β-estradiol in plasma of males exposed to o,p'-DDT, in addition to its estrogenic activity via the estrogen receptor. Significantly lower fertilization (p = 0.006) and hatchability (p = 0.019) were observed in the 13 intersex males. This study for the first time demonstrated the induction of intersex and reproductive effects of p,p'-DDE and o,p'-DDT at environmentally relevant concentrations.
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Jianxian
authors.initials: J
authors.lastname: Sun
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Peng
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Guomao
authors.initials: G
authors.lastname: Zheng
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Shiyi
authors.initials: S
authors.lastname: Zhang
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Jianying
authors.initials: J
authors.lastname: Hu
mesh_terms: D000818:Animals; D003634:DDT / Q000633:toxicity*; D003633:Dichlorodiphenyl Dichloroethylene / Q000633:toxicity*; D012734:Disorders of Sex Development / Q000139:chemically induced*; D004958:Estradiol / Q000032:analysis / Q000378:metabolism; D006066:Gonads / Q000187:drug effects*; D008297:Male; D009990:Oryzias; D014819:Vitellogenins / Q000032:analysis / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014819:Vitellogenins; D014874:Water Pollutants, Chemical; D003633:Dichlorodiphenyl Dichloroethylene; D004958:Estradiol; D003634:DDT; C016340:o,p'-DDT