Endocrine-disrupting chemicals, global warming and reproductive health in fishes

Abstract

Environmental stressors such as endocrine-disrupting chemicals (EDCs) and globally rising temperatures can impact gonadal sex or gamete production in vertebrates. While data from our laboratories and others suggest that the action of these stressors in teleost fishes can be mediated by disruption of thyroid hormone, stress hormone and melatonin production patterns, the physiological-molecular mechanisms of these actions and their interaction with the classical hypothalamus-pituitary-gonad (HPG) axis are not well understood. In this study, the effects of EDCs and thermal stress on thyroid and melatonin signaling will be examined in the biomedical animal modal, Zebrafish and the aquaculture species, Rainbow Trout. The expression of key genes involved in I-IPG, thyroid hormone, melatonin, and thermal stress signaling will be determined to characterize mechanisms. The information generated will be relevant to an assessment of the impacts of EDCs and global warming on the reproductive health of wild fishes. In addition, a better understanding of sex differentiation and gametogenesis may bring new options for improving current aquaculture technologies. (AU)