An environmentally relevant concentration of estrogen induces arrest of male gonad development in zebrafish, Danio rerio

The aim of the present study was to elucidate how full life-cycle exposure to estrogens impacts zebrafish development and reproduction, compared to partial life-cycle exposure only, and whether the estrogen-induced effects in zebrafish are reversible or irreversible. Zebrafish were exposed in a flow-through system to an environmentally relevant concentration (3 ng/L) of the synthetic estrogen 17alpha-ethinylestradiol (EE2) either from fertilization until the all-ovary stage of gonad development (i.e., 42 d postfertilization [DPF] in our experiment) or from fertilization until the reproductive stage (i.e., 118 DPF). Reversibility of the estrogen-induced effects was assessed after 58 d of depuration in EE2-free water until 176 DPE Early life exposure led to a lasting induction of plasma vitellogenin (VTG) in adult females but altered neither the sex ratio nor the reproductive capabilities. Full life-cycle exposure resulted in elevated VTG concentrations and caused gonadal feminization in 100% of exposed fish and thus inhibited reproduction. Two types of ovaries were observed in continuously exposed adult fish, immature ovaries with primary growth stage oocytes only and mature ovaries containing the full range of all oocyte maturation stages. Fish with immature ovaries had plasma VTG levels like control males, while fish with mature ovaries had female-like VTG levels. The effects of full life cycle exposure were at least partly reversible, and 26% of fish of the previous all-female cohort developed fully differentiated testes. These findings suggest that continuous estrogen exposure had arrested the developmental transition of the gonads of genetic males from the early all-ovary stage to functional testes. After the exposure had ceased, however, these males apparently were able to accomplish testicular differentiation.

[1]  Andrew A. Rooney,et al.  Organization versus activation: the role of endocrine-disrupting contaminants (EDCs) during embryonic development in wildlife. , 1995, Environmental health perspectives.

[2]  D. Tillitt,et al.  An in vivo model fish system to test chemical effects on sexual differentiation and development: exposure to ethinyl estradiol , 2000 .

[3]  Hiroya Takahashi.  Juvenile Hermaphroditism in the Zebrafish, Brachydanio rerio , 1977 .

[4]  R. Zoeller,et al.  Evaluating the effects of endocrine disruptors on endocrine function during development. , 1999, Environmental health perspectives.

[5]  A. Goksøyr,et al.  Development and validation of an enzyme‐linked immunosorbent assay to measure vitellogenin in the zebrafish (Danio rerio) , 2002, Environmental toxicology and chemistry.

[6]  R. Wallace,et al.  Stages of oocyte development in the zebrafish, Brachydanio rerio , 1993, Journal of morphology.

[7]  Masanori Seki,et al.  Effect of ethinylestradiol on the reproduction and induction of vitellogenin and testis‐ova in medaka (Oryzias latipes) , 2002, Environmental toxicology and chemistry.

[8]  R. Hill,et al.  Developmental estrogenic exposure in zebrafish (Danio rerio): II. Histological evaluation of gametogenesis and organ toxicity. , 2003, Aquatic toxicology.

[9]  K. Hanaoka.  [Sex differentiation]. , 1968, Horumon to rinsho. Clinical endocrinology.

[10]  H. Segner,et al.  Aromatase modulation alters gonadal differentiation in developing zebrafish (Danio rerio). , 2004, Aquatic toxicology.

[11]  A Wenzel,et al.  Identification of endocrine-disrupting effects in aquatic vertebrates and invertebrates: report from the European IDEA project. , 2003, Ecotoxicology and environmental safety.

[12]  H. Holbech,et al.  Effects of exposure to 17α-ethinylestradiol during early development on sexual differentiation and induction of vitellogenin in zebrafish (Danio rerio) , 2003 .

[13]  T. Runnalls,et al.  Ontogeny of gonadal sex development relative to growth in fathead minnow , 2004 .

[14]  R. Verheyen,et al.  Effects of 17alpha-ethynylestradiol in a partial life-cycle test with zebrafish (Danio rerio): effects on growth, gonads and female reproductive success. , 2003, The Science of the total environment.

[15]  M. Scholze,et al.  Assessing the biological potency of binary mixtures of environmental estrogens using vitellogenin induction in juvenile rainbow trout (Oncorhynchus mykiss). , 2001, Environmental science & technology.

[16]  T. Iguchi,et al.  Oocyte apoptosis during the transition from ovary-like tissue to testes during sex differentiation of juvenile zebrafish. , 2002, The Journal of experimental biology.

[17]  S. Hamaguchi,et al.  Evidence for the sexual bipotentiality of spermatogonia in the fish, Oryzias latipes. , 1988, The Journal of experimental zoology.

[18]  Erin M. Snyder,et al.  Effects of 4‐nonylphenol on fecundity and biomarkers of estrogenicity in fathead minnows (Pimephales promelas) , 2000 .

[19]  J. Sumpter,et al.  Effects of the synthetic estrogen 17α‐ethinylestradiol on the life‐cycle of the fathead minnow (Pimephales promelas) , 2001 .

[20]  Henrik Holbech,et al.  Gonad development and vitellogenin production in zebrafish (Danio rerio) exposed to ethinylestradiol and methyltestosterone. , 2003, Aquatic toxicology.

[21]  R. Hill,et al.  Developmental estrogenic exposure in zebrafish (Danio rerio): I. Effects on sex ratio and breeding success. , 2003, Aquatic toxicology.

[22]  C. Tyler,et al.  Impacts of 17β-estradiol, including environmentally relevant concentrations, on reproduction after exposure during embryo-larval-, juvenile- and adult-life stages in zebrafish (Danio rerio) , 2004 .

[23]  T. Ternes,et al.  Nachweis von natürlichen und synthetischen Östrogenen in Kläranlagen und Fliessgewässern , 1996 .

[24]  R. Verheyen,et al.  Effects of ethynylestradiol on the reproductive physiology in zebrafish (Danio rerio): Time dependency and reversibility , 2002, Environmental toxicology and chemistry.

[25]  C. Tyler,et al.  Impacts of 17beta-estradiol, including environmentally relevant concentrations, on reproduction after exposure during embryo-larval-, juvenile- and adult-life stages in zebrafish (Danio rerio). , 2004, Aquatic toxicology.

[26]  G. Aherne,et al.  The relevance of the presence of certain synthetic steroids in the aquatic environment , 1989, The Journal of pharmacy and pharmacology.

[27]  G. Ankley,et al.  Description and evaluation of a short‐term reproduction test with the fathead minnow (Pimephales promelas) , 2001, Environmental toxicology and chemistry.

[28]  M. Servos,et al.  Behavior and occurrence of estrogens in municipal sewage treatment plants--I. Investigations in Germany, Canada and Brazil. , 1999, The Science of the total environment.

[29]  S. Teh,et al.  Determining the sensitive developmental stages of intersex induction in medaka (Oryzias latipes) exposed to 17 beta-estradiol or testosterone. , 2000, Marine environmental research.

[30]  Scholz,et al.  17-alpha-ethinylestradiol affects reproduction, sexual differentiation and aromatase gene expression of the medaka (Oryzias latipes). , 2000, Aquatic toxicology.

[31]  Ronny van Aerle,et al.  Window of Sensitivity for the Estrogenic Effects of Ethinylestradiol in Early Life-Stages of Fathead Minnow, Pimephales promelas , 2002, Ecotoxicology.

[32]  Richard J. Williams,et al.  Steroid estrogens profiles along river stretches arising from sewage treatment works discharges. , 2003, Environmental science & technology.

[33]  H Segner,et al.  Development and validation of a homologous zebrafish (Danio rerio Hamilton-Buchanan) vitellogenin enzyme-linked immunosorbent assay (ELISA) and its application for studies on estrogenic chemicals. , 2001, Comparative biochemistry and physiology. Toxicology & pharmacology : CBP.

[34]  W. Benson,et al.  Reproduction and development of Japanese medaka following an early life stage exposure to xenoestrogens , 1998 .

[35]  Edwin J. Routledge,et al.  Identification of Estrogenic Chemicals in STW Effluent. 2. In Vivo Responses in Trout and Roach , 1998 .

[36]  P. Bjerregaard,et al.  Vitellogenin induction by 17β-estradiol and 17α-ethinylestradiol in male zebrafish (Danio rerio) , 2002 .

[37]  C. Tyler,et al.  An in vivo testing system for endocrine disruptors in fish early life stages using induction of vitellogenin , 1999 .

[38]  A. D. Vethaak,et al.  Analysis and occurrence of estrogenic hormones and their glucuronides in surface water and waste water in The Netherlands. , 1999, The Science of the total environment.

[39]  Helmut Segner,et al.  Morphological development of the gonads in zebrafish , 2003 .

[40]  S. Abe,et al.  Aromatase inhibitor and 17α‐methyltestosterone cause sex‐reversal from genetical females to phenotypic males and suppression of P450 aromatase gene expression in Japanese flounder (Paralichthys olivaceus) , 2000, Molecular reproduction and development.

[41]  Edwin J. Routledge,et al.  Identification of Estrogenic Chemicals in STW Effluent. 1. Chemical Fractionation and in Vitro Biological Screening , 1998 .

[42]  R. Devlin,et al.  Brief treatment with an aromatase inhibitor during sex differentiation causes chromosomally female salmon to develop as normal, functional males , 1994 .