Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University , Gent, Belgium.
Environ Sci Technol. 2014 Mar 18;48(6):3513-22. doi: 10.1021/es4053363. Epub 2014 Feb 26.
The present study investigated the possibilities and limitations of implementing a genome-wide transcription-based approach that takes into account genetic and environmental variation to better understand the response of natural populations to stressors. When exposing two different Daphnia pulex genotypes (a cadmium-sensitive and a cadmium-tolerant one) to cadmium, the toxic cyanobacteria Microcystis aeruginosa, and their mixture, we found that observations at the transcriptomic level do not always explain observations at a higher level (growth, reproduction). For example, although cadmium elicited an adverse effect at the organismal level, almost no genes were differentially expressed after cadmium exposure. In addition, we identified oxidative stress and polyunsaturated fatty acid metabolism-related pathways, as well as trypsin and neurexin IV gene-families as candidates for the underlying causes of genotypic differences in tolerance to Microcystis. Furthermore, the whole-genome transcriptomic data of a stressor mixture allowed a better understanding of mixture responses by evaluating interactions between two stressors at the gene-expression level against the independent action baseline model. This approach has indicated that ubiquinone pathway and the MAPK serine-threonine protein kinase and collagens gene-families were enriched with genes showing an interactive effect in expression response to exposure to the mixture of the stressors, while transcription and translation-related pathways and gene-families were mostly related with genotypic differences in interactive responses to this mixture. Collectively, our results indicate that the methods we employed may improve further characterization of the possibilities and limitations of transcriptomics approaches in the adverse outcome pathway framework and in predictions of multistressor effects on natural populations.
本研究探讨了实施基于全基因组转录组的方法的可能性和局限性，该方法考虑了遗传和环境变异，以更好地理解自然种群对胁迫的反应。当将两种不同的溞属（一种对镉敏感，一种对镉耐受）暴露于镉、有毒蓝藻铜绿微囊藻及其混合物中时，我们发现转录组水平的观察结果并不总是能解释更高水平（生长、繁殖）的观察结果。例如，尽管镉在机体水平上产生了不利影响，但镉暴露后几乎没有基因表达差异。此外，我们确定了氧化应激和多不饱和脂肪酸代谢相关途径，以及胰蛋白酶和神经连接蛋白 IV 基因家族，作为耐受微囊藻的基因型差异的潜在原因的候选者。此外，应激混合物的全基因组转录组数据通过在基因表达水平上评估两种应激物之间的相互作用对独立作用基线模型，从而更好地理解混合物的反应。这种方法表明，在混合物暴露的表达反应中，泛醌途径和丝裂原激活蛋白激酶丝氨酸-苏氨酸蛋白激酶和胶原基因家族的基因富集了表现出相互作用效应的基因，而转录和翻译相关途径和基因家族主要与对这种混合物的相互作用的基因型差异有关。总的来说，我们的研究结果表明，我们采用的方法可能会进一步提高对全基因组转录组方法在不利结局途径框架中的可能性和局限性的描述，并能更好地预测多应激物对自然种群的影响。
Zotero 插件
