Forsøksdyr: EPISIP-WP3

Godkjenningsdato 28.06.2018

The aim of this zebrafish experiment is to investigate if parental supplementation of nutrients involved in the one carbon (1C) cycle, also known as methyl donor nutrients, can ameliorate the effects of contaminants through influencing DNA methylation. Research has shown that the levels of micronutrients such as vitamins in parents can affect the long-term health of their offspring. 1C-cycle nutrients including folate, methionine and the cofactors vitamin B6 and B12 are central factors in nutrient-induced changes to epigenetic gene regulation and play also important roles in energy metabolism and transamination reactions. In mammals, deficiencies in 1C-related substrates around the conception period may lead to epigenetic alterations in DNA and histone methylation in genes encoding proteins that regulate essential developmental processes in the embryo. In Atlantic salmon farming, novel feeds with high levels of plant-based ingredients have lower levels of many B-vitamins and indispensable amino acids compared to fish ingredient-based diets. At the same time, plant-based diets may also contain elevated levels of pesticides of which some act as endocrine disruptors. To counteract the potential negative impact of these contaminants, novel salmon feed might need higher supplementation of certain 1C-nutrients. In this project, we use zebrafish as a model to study the role of parental 1C status on the potential negative impact of selected environmental stressors on the offspring. The chosen contaminants (bisphenol A (BPA), hexabromobenzene (HBB), dichlorodiphenyldichloroethylene (DDE)) are a concern for fish health. The transgenerational design involves 1080 zebrafish (F0: 120; F1: 960). F1 embryos will be exposed to the selected contaminants from 2-5 days post fertilization (DPF) and they will grow into adulthood in order to follow up development, morphology, behavior and reproductive performance. Exposure to the low concentrated stressors at embryonic stage can be considered as mild distress.
Results from this study will clarify if 1C-nutrient supplementation in fish feed can ameliorate effects of contaminants in order to improve fish health and welfare. Furthermore, the results will elucidate if epigenetic mechanisms need to be considered when examining toxicity of fish feed contaminants.