Exposure to diethylstilbestrol during embryonic and larval stages of medaka fish (Oryzias latipes) leads to sex reversal in genetic males and reduced gonad weight in genetic females.

Molecular and cellular mechanisms involved in artificially induced ovarian differentiation were analyzed by exposing embryos of medaka (Oryzias latipes) to a potent nonsteroidal estrogen, diethylstilbestrol (DES). Embryos were exposed for short-exposure (SE) [from 0 to 8 d postfertilization (dpf)] and long-exposure (LE) periods (from 0 to 18/28 dpf) to 1 ng/ml of DES, and status of sexual differentiation in somatic and germ cells of these gonads was analyzed at 8, 18, and 28 dpf by histology, cell proliferation assays, TUNEL assay, and in situ hybridization using sex-specific somatic and germ cell markers. Additionally, gonads of exposed fry were examined after withdrawal of DES to see whether effects of DES in exposed fish were reversible or not. DES induced germ cell proliferation and meiosis in XY fry of SE and LE groups. However, SE induced only a partial reduction in expression of gonadal soma-derived factor, the male-dominant somatic cell marker, and was not sufficient to induce ovarian development after withdrawal of DES. On the contrary, LE resulted in complete loss of such male-specific gene expression in somatic cells of XY gonads, and these gonads underwent sustained ovarian development even after withdrawal of DES. Importantly, LE to DES affected germ cell proliferation in XX gonads adversely during early stages of sexual differentiation, leading to reduced gonad weight in adulthood. Interestingly, apoptosis was not the cause for reduction in germ cell number. Taken together, these results indicated that DES exposure has long-lasting effects on the gonadal development in genetic males (sex reversal) and females (reduced gonad weight) of medaka.

[1]  Masaru Nakamura,et al.  Sex Determination in Fishes , 2011 .

[2]  T. Usami,et al.  Expression of gonadal soma derived factor (GSDF) is spatially and temporally correlated with early testicular differentiation in medaka. , 2010, Gene expression patterns : GEP.

[3]  P. Zhang,et al.  Histopathological and gene expression analysis of mice exposed to diethylstilbestrol , 2010, Toxicology mechanisms and methods.

[4]  F. Piferrer,et al.  Ovarian aromatase and estrogens: a pivotal role for gonadal sex differentiation and sex change in fish. , 2010, General and comparative endocrinology.

[5]  N. Shimizu,et al.  Two distinct types of theca cells in the medaka gonad: Germ cell‐dependent maintenance of cyp19a1‐expressing theca cells , 2009, Developmental dynamics : an official publication of the American Association of Anatomists.

[6]  B. Brunström,et al.  Effects of estrogens on sex differentiation in Japanese quail and chicken. , 2009, General and comparative endocrinology.

[7]  D. Saito,et al.  Comparative Aspects of Gonadal Sex Differentiation in Medaka: A Conserved Role of Developing Oocytes in Sexual Canalization , 2009, Sexual Development.

[8]  J. Giesy,et al.  In situ hybridization to detect spatial gene expression in medaka. , 2009, Ecotoxicology and environmental safety.

[9]  F. Piferrer,et al.  Masculinization of the European sea bass (Dicentrarchus labrax) by treatment with an androgen or aromatase inhibitor involves different gene expression and has distinct lasting effects on maturation. , 2009, General and comparative endocrinology.

[10]  D. Baron,et al.  Estrogen treatment up-regulates female genes but does not suppress all early testicular markers during rainbow trout male-to-female gonadal transdifferentiation. , 2008, Journal of molecular endocrinology.

[11]  J. Toppari.  Environmental Endocrine Disrupters , 2008, Sexual Development.

[12]  Paul D. Jones,et al.  Fluorescence in situ hybridization techniques (FISH) to detect changes in CYP19a gene expression of Japanese medaka (Oryzias latipes). , 2008, Toxicology and applied pharmacology.

[13]  S. Weng,et al.  Sexually disrupting effects of nonylphenol and diethylstilbestrol on male silver carp (Carassius auratus) in aquatic microcosms. , 2008, Ecotoxicology and environmental safety.

[14]  M. Esaki,et al.  Effects of gestational diethylstilbestrol treatment on male and female gonads during early embryonic development. , 2008, Endocrinology.

[15]  D. Saito,et al.  Germ cells are essential for sexual dimorphism in the medaka gonad , 2007, Proceedings of the National Academy of Sciences.

[16]  G. Yoshizaki,et al.  A novel transforming growth factor-beta superfamily member expressed in gonadal somatic cells enhances primordial germ cell and spermatogonial proliferation in rainbow trout (Oncorhynchus mykiss). , 2007, Developmental biology.

[17]  Tohru Kobayashi,et al.  Knock-down of DMY initiates female pathway in the genetic male medaka, Oryzias latipes. , 2006, Biochemical and biophysical research communications.

[18]  R. Newbold,et al.  Adverse effects of the model environmental estrogen diethylstilbestrol are transmitted to subsequent generations. , 2006, Endocrinology.

[19]  Daniel L Villeneuve,et al.  Relationship between brain and ovary aromatase activity and isoform-specific aromatase mRNA expression in the fathead minnow (Pimephales promelas). , 2006, Aquatic toxicology.

[20]  Y. Kato,et al.  Effects of Estradiol-17β on Germ Cell Proliferation and DMY Expression during Early Sexual Differentiation of the Medaka Oryzias latipes , 2005 .

[21]  Ying Xu,et al.  The Chinese rare minnow (Gobiocypris rarus) as an in vivo model for endocrine disruption in freshwater teleosts: a full life-cycle test with diethylstilbestrol. , 2005, Aquatic toxicology.

[22]  K. Korach,et al.  Estrogen receptor-alpha mediates the detrimental effects of neonatal diethylstilbestrol (DES) exposure in the murine reproductive tract. , 2004, Toxicology.

[23]  Tohru Kobayashi,et al.  Two DM domain genes, DMY and DMRT1, involved in testicular differentiation and development in the medaka, Oryzias latipes , 2004, Developmental dynamics : an official publication of the American Association of Anatomists.

[24]  Minoru Tanaka,et al.  Expression of aromatase mRNA and effects of aromatase inhibitor during ovarian development in the medaka, Oryzias latipes. , 2004, Journal of experimental zoology. Part A, Comparative experimental biology.

[25]  Y. Nagahama,et al.  Induction of XY sex reversal by estrogen involves altered gene expression in a teleost, tilapia , 2003, Cytogenetic and Genome Research.

[26]  M. Schartl,et al.  A duplicated copy of DMRT1 in the sex-determining region of the Y chromosome of the medaka, Oryzias latipes , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[27]  M. Sakaizumi,et al.  Sex reversal of genetic females (XX) induced by the transplantation of XY somatic cells in the medaka, Oryzias latipes. , 2002, The International journal of developmental biology.

[28]  R. Devlin,et al.  Sex determination and sex differentiation in fish: an overview of genetic, physiological, and environmental influences , 2002 .

[29]  Shuichi Asakawa,et al.  DMY is a Y-specific DM-domain gene required for male development in the medaka fish , 2002, Nature.

[30]  J. Verloop,et al.  Hypospadias in sons of women exposed to diethylstilbestrol in utero: a cohort study , 2002, The Lancet.

[31]  A. Kanamori.  Systematic identification of genes expressed during early oogenesis in medaka , 2000, Molecular reproduction and development.

[32]  R. Sharpe,et al.  Abnormalities in functional development of the Sertoli cells in rats treated neonatally with diethylstilbestrol: a possible role for estrogens in Sertoli cell development. , 1998, Biology of reproduction.

[33]  A. Shimada,et al.  Sex-Linked Inheritance of the lf Locus in the Medaka Fish (Oryzias latipes) , 1998, Zoological science.

[34]  Y. Uesugi,et al.  Polyovular follicles in mouse ovaries exposed neonatally to diethylstilbestrol in vivo and in vitro. , 1990, Biology of reproduction.