INVESTIGADORES
SOMOZA Gustavo Manuel
artículos
Título:
Feminization and altered gonadal gene expression profile by ethynylestradiol exposure to pejerrey, Odontesthes bonariensis, a South American teleost fish.
Autor/es:
MARÍA R. PÉREZ; JUAN IGNACIO FERNANDINO; PEDRO CARRIQUIRIBORDE; GUSTAVO M. SOMOZA
Revista:
ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
Editorial:
SETAC PRESS
Referencias:
Año: 2012 p. 941 - 946
ISSN:
0730-7268
Resumen:
In pejerrey, ovarian differentiation has been associated with gonadal aromatase expression. It is also known that exposure of pejerrey larvae to estradiol (E2) produces all female populations. During the last years the presence of ethynylestradiol (EE2), a synthetic E2 analogue, has been reported in water reservoirs of different parts of the world. In the present work, the effects of EE2 were assessed on sex ratio bias and gene expression levels of gonadal aromatase (cyp19a1a), 11β-hydroxysteroid deshydrogenase type 2 (hsd11b2), estrogens (erα, erβ1) and androgens receptors (arα, arβ). Pejerrey larvae were fed with commercial food containing EE2 (0.1 µg/g and 1 µg/g), and E2 (50 µg/g) as a positive control for six weeks after hatching. The gonadal histological analysis showed that 42 to 46% of the fish had clearly differentiated ovaries both, in the EE2 and E2 treated groups, compared to 27 % in the control group. Moreover, in the EE2 (1 µg/g) and E2 treated groups, no fish presented signs of testicular development compared to controls. In addition, the expression of cyp19a1a and hsd11b2 were significantly up- and down-regulated respectively by EE2 and E2. Our results suggested that the feminization process driven by EE2 depends on the positive balance of cyp19a1a in relation to hsd11b2. These genes can then be used as early indicators of exposure to xenoestrogens in this species.