Aquatic Toxicology ( IF 4.5 ) Pub Date : 2018-10-02 , DOI: 10.1016/j.aquatox.2018.09.015 Pauline Cribiu , Arnaud Chaumot , Olivier Geffard , Jean-Luc Ravanat , Thérèse Bastide , Nicolas Delorme , Hervé Quéau , Sylvain Caillat , Alain Devaux , Sylvie Bony
To improve the assessment of aquatic organism responses to environmental stressors, there is an interest in studying epigenetic marks in addition to other validated biomarkers. Indeed, the epigenetic marks may be influenced by the surrounding environment. Non-model invertebrates such as gammarids are sentinel organisms representative of the diversity of natural stream communities. Despite their ecologically relevance, the epigenetic responses have been to date poorly documented in these species. The present study explores the measurement of the global cytosine methylation level in the genome of the freshwater crustacean Gammarus fossarum. In a first step, natural variability of global cytosine methylation level (basal level) was assessed by studying the effect of sex, age and sampling site of organisms. Results showed a significant effect of age and sampling site. In a second step, effects of water temperature and food starvation were studied. For both factors, a hypermethylation was observed after 1 month of exposure. In a third step, gammarids were exposed to a range of environmentally relevant cadmium concentrations (0.05–5 μg/L) in order to assess the effect of a chemical stress. Whatever the cadmium concentration used, a significant hypomethylation was observed after 14 days followed by a trend for hypermethylation after 1 month of exposure. These results are the first ones dealing with the 5C-methylation status in gammarids. The results constitute potential markers of environmental stresses in relevant sentinel species widely used in ecotoxicological studies.
中文翻译:
环境变量对淡水甲壳类动物Gammarus fossarum中全球基因组胞嘧啶甲基化水平的自然变异和调控
为了改善对水生生物对环境压力的反应的评估,除其他经过验证的生物标记外,还有兴趣研究表观遗传标记。实际上,表观遗传标记可能会受到周围环境的影响。非模型无脊椎动物(如伽马龙)是前哨生物,代表自然河流群落的多样性。尽管它们在生态上具有相关性,但迄今为止在这些物种中尚无文献记载表观遗传反应。本研究探索了淡水甲壳类Gammarus fossarum基因组中全球胞嘧啶甲基化水平的测量。第一步,通过研究性别,年龄和生物取样部位的影响,评估总体胞嘧啶甲基化水平(基础水平)的自然变异性。结果显示年龄和采样地点有显着影响。第二步,研究了水温和食物饥饿的影响。对于这两个因素,在暴露1个月后均观察到甲基化过高。第三步,将γ-内酰胺类暴露于一系列与环境有关的镉浓度(0.05-5μg/ L)中,以评估化学胁迫的影响。无论使用哪种镉浓度,在14天后都会观察到明显的低甲基化,然后在暴露1个月后出现高甲基化的趋势。这些结果是处理γ-内酰胺基中5C-甲基化状态的第一批结果。