Asselman Jana, De Coninck Dieter I M, Vandegehuchte Michiel B, Jansen Mieke, Decaestecker Ellen, De Meester Luc, Vanden Bussche Julie, Vanhaecke Lynn, Janssen Colin R, De Schamphelaere Karel A C
Laboratory for Environmental Toxicology and Aquatic Ecology (GhEnToxLab), Ghent University, Ghent, Belgium.
Environ Toxicol Chem. 2015 May;34(5):1056-61. doi: 10.1002/etc.2887. Epub 2015 Mar 19.
The authors characterized global cytosine methylation levels in 2 different genotypes of the ecotoxicological model organism Daphnia magna after exposure to a wide array of biotic and abiotic environmental stressors. The present study aimed to improve the authors' understanding of the role of cytosine methylation in the organism's response to environmental conditions. The authors observed a significant genotype effect, an environment effect, and a genotype × environment effect. In particular, global cytosine methylation levels were significantly altered after exposure to Triops predation cues, Microcystis, and sodium chloride compared with control conditions. Significant differences between the 2 genotypes were observed when animals were exposed to Triops predation cues, Microcystis, Cryptomonas, and sodium chloride. Despite the low global methylation rate under control conditions (0.49-0.52%), global cytosine methylation levels upon exposure to Triops demonstrated a 5-fold difference between the genotypes (0.21% vs 1.02%). No effects were found in response to arsenic, cadmium, fish, lead, pH of 5.5, pH of 8, temperature, hypoxia, and white fat cell disease. The authors' results point to the potential role of epigenetic effects under changing environmental conditions such as predation (i.e., Triops), diet (i.e., Cryptomonas and Microcystis), and salinity. The results of the present study indicate that, despite global cytosine methylation levels being low, epigenetic effects may be important in environmental studies on Daphnia.
作者对生态毒理学模式生物大型溞的两种不同基因型在暴露于一系列生物和非生物环境应激源后的全基因组胞嘧啶甲基化水平进行了表征。本研究旨在增进作者对胞嘧啶甲基化在生物体对环境条件反应中的作用的理解。作者观察到显著的基因型效应、环境效应以及基因型×环境效应。特别是，与对照条件相比，暴露于鲎虫捕食线索、微囊藻和氯化钠后，全基因组胞嘧啶甲基化水平发生了显著变化。当动物暴露于鲎虫捕食线索、微囊藻、隐滴虫和氯化钠时，观察到两种基因型之间存在显著差异。尽管在对照条件下全基因组甲基化率较低（0.49 - 0.52%），但暴露于鲎虫后，两种基因型的全基因组胞嘧啶甲基化水平相差5倍（0.21%对1.02%）。未发现对砷、镉、鱼类、铅、pH值5.5、pH值8、温度、缺氧和白色脂肪细胞病有反应。作者的结果表明，在诸如捕食（即鲎虫）、饮食（即隐滴虫和微囊藻）和盐度等不断变化的环境条件下，表观遗传效应可能发挥潜在作用。本研究结果表明，尽管全基因组胞嘧啶甲基化水平较低，但表观遗传效应在大型溞的环境研究中可能很重要。
