Synergistic interactions of biotic and abiotic environmental stressors on gene expression
Synergistic interactions of biotic and abiotic environmental stressors on gene expression
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DOI：
10.1139/gen-2015-0045
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发表时间：
2015-03-01
期刊：
影响因子：
3.1
通讯作者：
Cristescu, Melania E.
中科院分区：
文献类型：
--
作者：
Altshuler, Ianina;McLeod, Anne M.;Cristescu, Melania E.
了解生物体对多种压力源的反应对于预测种群是否能够适应快速的环境变化至关重要。自然和人为的压力往往相互作用，使一般的预测复杂化。在这项研究中，我们研究了两种常见的环境压力，降低钙浓度，人为的压力，和捕食者的存在，自然的压力，水蚤蚤状的相互作用和累积效应。我们分析了五个基因的表达变化参与钙稳态角质层蛋白（Cutie，Icp 2），钙结合蛋白（Calb），钙泵和通道（Serca和Ip 3R）-使用实时定量PCR（RT-qPCR）在全因子实验。我们观察到低钙浓度和捕食者的存在之间的强协同作用。虽然Ip 3R基因不受压力的影响，其他四个基因的影响，在其转录水平的组合的压力。编码角质层蛋白（Cutie和Icp 2）和肌浆钙泵（Serca）的基因的转录模式只对压力源的组合做出反应，在协同反应中改变它们的相对表达水平，而钙结合蛋白（Calb）对低钙压力和两种压力源的组合做出反应。这些基因（Cutie，Icp 2和Serca）的表达模式是非线性的，但它们在钙梯度上具有剂量依赖性。多种压力源可能对生态系统产生复杂的、往往是意想不到的影响。这项研究表明，测试基因组的主导相互作用似乎是协同作用。我们认为，基因表达模式可以用来理解和预测生物体同时暴露于自然和人为压力时预期的相互作用的类型。
Understanding the response of organisms to multiple stressors is critical for predicting if populations can adapt to rapid environmental change. Natural and anthropogenic stressors often interact, complicating general predictions. In this study, we examined the interactive and cumulative effects of two common environmental stressors, lowered calcium concentration, an anthropogenic stressor, and predator presence, a natural stressor, on the water flea Daphnia pulex. We analyzed expression changes of five genes involved in calcium homeostasis-cuticle proteins (Cutie, Icp2), calbindin (Calb), and calcium pump and channel (Serca and Ip3R)-using real-time quantitative PCR (RT-qPCR) in a full factorial experiment. We observed strong synergistic interactions between low calcium concentration and predator presence. While the Ip3R gene was not affected by the stressors, the other four genes were affected in their transcriptional levels by the combination of the stressors. Transcriptional patterns of genes that code for cuticle proteins (Cutie and Icp2) and a sarcoplasmic calcium pump (Serca) only responded to the combination of stressors, changing their relative expression levels in a synergistic response, while a calcium-binding protein (Calb) responded to low calcium stress and the combination of both stressors. The expression pattern of these genes (Cutie, Icp2, and Serca) were nonlinear, yet they were dose dependent across the calcium gradient. Multiple stressors can have complex, often unexpected effects on ecosystems. This study demonstrates that the dominant interaction for the set of tested genes appears to be synergism. We argue that gene expression patterns can be used to understand and predict the type of interaction expected when organisms are exposed simultaneously to natural and anthropogenic stressors.