Queensland University of Technology, Brisbane, QLD, 4001, Australia.
University of Queensland, St Lucia, QLD, 4072, Australia.
Sci Rep. 2017 Oct 27;7(1):14263. doi: 10.1038/s41598-017-14736-8.
Understanding the molecular mechanisms of organismal response to human-derived ecosystem change is recognised as a critical tool in monitoring and managing impacts, especially in freshwater systems. Fundamental to this approach is to determine the genes involved in responding to ecosystem change and detect modifications to their expression and activity in natural populations. Potential targets for this approach include well-known detoxification genes that are upregulated in response to stress. Here, we tested whether expression of such genes varied in association with differences in ecosystem health and could be detected in the field. We sampled populations of the freshwater midge, Cricotopus draysoni, from two geographically proximate sites in southeast Queensland, Australia, which differed in their ecosystem health, at multiple time points. We assessed transcriptome-level differential gene expression and predicted greatest differential expression between sites, associated with organismal responses to local physico-chemical factors. In contrast, we observed a clear and dramatic difference in gene expression - including of known detoxification genes - between time points, specifically between periods at the start and end of the austral summer rainfall when in-stream water levels are most different. These data suggest that these waterways experience greatest pollution load when water levels are high following rainfall events.
了解生物体对人类引起的生态系统变化的反应的分子机制，被认为是监测和管理影响的关键工具，特别是在淡水系统中。这种方法的基础是确定参与响应生态系统变化的基因，并检测其在自然种群中的表达和活性的变化。这种方法的潜在目标包括对压力有反应而上调的众所周知的解毒基因。在这里，我们测试了这些基因的表达是否与生态系统健康的差异有关，并且是否可以在野外检测到。我们从澳大利亚昆士兰州东南部两个地理位置相近的地点采集了淡水摇蚊 Cricotopus draysoni 的种群样本，这些地点的生态系统健康状况在多个时间点存在差异。我们评估了转录组水平的差异基因表达，并预测了与生物体对当地理化因素的反应相关的最大差异表达。相比之下，我们观察到基因表达之间存在明显而显著的差异，包括已知的解毒基因，特别是在澳大利亚夏季降雨开始和结束时，溪流中的水位差异最大时。这些数据表明，这些水道在降雨事件后水位升高时经历了最大的污染负荷。
