Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.cca.2004.09.004
Title (Primary) Life-stage-dependent sensitivity of zebrafish (Danio rerio) to estrogen exposure
Author Maack, G.; Segner, H.
Journal Comparative Biochemistry and Physiology C-Toxicology & Pharmacology
Year 2004
Department OEC; COE
Volume 139
Issue 1-3
Page From 47
Page To 55
Language englisch
Keywords Zebrafish; Danio rerio; 17a-ethynylestradiol; Gonadal development; Gonad histology; Reproduction; Sexual differentiation; Stage-specific exposure
Abstract The aim of this study was to identify periods in zebrafish (Danio rerio) development when estrogen exposure has long-term consequences on reproductive capabilities at the adult stage. To this end, zebrafish were exposed to 10 ng/L ethynylestradiol (EE2) during three stages of gonadal differentiation: (i) the juvenile hermaphroditic stage when gonads display the morphology of an immature ovary (in our zebrafish colony this lasted from 15 to 42 days post-fertilization [dpf]), (ii) the gonad transition stage when the hermaphroditic gonad differentiates into either testes or ovary (from 43 to day 71 dpf), and (iii) the premature stage of testicular and ovarian development (from 72 to 99 dpf). The consequences of stage-specific exposure to EE2 were assessed by determining time to first spawning, fecundity (number of eggs per female per day), fertilization success (percentage of fertilized eggs) and sex ratio of the adults. Exposure during the gonad transition period induced a delay in the onset of spawning and a significant reduction of fecundity and fertilization success, whereas exposure during the hermaphroditic stage or during the premature stage had no significant impact on the reproductive parameters of adult fish. The results from this experiment pointed to the gonad transition stage as being most susceptible to persistent effects of developmental estrogen exposure. In a second experiment, the concentration dependency of the EE2effects was evaluated by exposing zebrafish during the gonad transition stage (43-71 dpf) to 1.67, 3 or 10 ng EE2/L. Significant effects of EE2 on adult reproduction were found with 3 and 10 ng EE2/L, but not with 1.67 ng/L. Histological examination of the gonads revealed that at termination of EE2 exposure (71 dpf), all individuals in the 3 and 10 ng EE2/L treatment possessed ovaries. However, this feminising effect appeared to be reversible since at the adult stage (190 dpf), both fish with ovaries and with testes were found. Thus, EE2 exposure during the gonad transition stage seems to have no persistent effect on gonad histology but on reproductive capabilities.
Persistent UFZ Identifier
Maack, G., Segner, H. (2004):
Life-stage-dependent sensitivity of zebrafish (Danio rerio) to estrogen exposure
Comp. Biochem. Physiol. C-Toxicol. Pharmacol. 139 (1-3), 47 - 55