Environmetal Cues Influence EDCs-Mediated Endocrine Disruption Effects In Model Fish

In recent years, the potential adverse effects of endocrine disrupting chemicals (EDCs) in wildlife and human have become a major research issue, and this chemicals would bring about increasing in cancers, reducing reproductive function and disrupting development of immune and nervous systems, however, it is little known whether or not the ambient conditions such as temperature and photoperiod can affect on endocrine disruption induced by EDCs in fish. Moreover, the established experimental systems always ignore the effects of the conditions of exposure on the environmental risk assessment of chemicals.In the research of the effects of the conditions of photoperiod and temperature on the endocrine disrupting in zebrafish, we found that zebrafish hepatic estrogen-responsive gene transcription levels were greatly affected by temperature and photoperiod after two days exposure. Estrogen-responsive gene transcription levels at lower temperatures and with shorter photoperiods were significantly lower than those at higher temperatures and with longer photoperiods upon exposure to nonylphenol (NP) or17(3-estradiol (E2). Two-way analysis of variance revealed a significant interaction between temperature and photoperiod in hepatic Vtgl and ERα gene transcription in both high and low concentration treatment groups upon exposure to E2. However, no significant interactions groups upon exposure to NP in the experiment at long-term. We also found that temperature and photoperiod significantly influence the transcription of the estrogen-responsive genes after a21-day exposure to environmentally relevant concentrations of17a-ethynyl-estradiol (EE2), NP and EE2plus NP (EE2+NP). In the present study, we obtained clearly elucidate that temperature and photoperiod greatly influence the effect of EDCs.In order to better resolve environmental factors mediated endocrine disruptors on fish at different developmental stages. In the study of different developmental stages of Japanese medaka exposure to environmentally relevant concentrations of E2and NP for7days, the results suggest that juveniles of both sexes and adult males were more sensitive to temperature and photoperiod changes than larval and adult female medaka. Specifically, two-way analysis indicated that both NP and E2-mediated induction of Vtgl mRNA expression interacted with environmental cues (temperature and photoperiod) and exposure concentrations in a developmental sex-and stage-specific manner.In conclusion, temperature and photoperiod significantly influence the transcription of the estrogen-responsive genes, and could confound the risk assessment of estrogenic chemicals. Thus, to assess the endocrine disrupting effects of environmental chemicals should take seasonal and/or climate changes into account, and the changes of temperature and photoperiod have potential implications for future environmental monitoring studies.