Melwani A R, Thompson E L, Raftos D A
Department of Biological Sciences, Macquarie University, NSW 2109, Australia; Sydney Institute of Marine Science, NSW 2088, Australia.
Department of Biological Sciences, Macquarie University, NSW 2109, Australia; Sydney Institute of Marine Science, NSW 2088, Australia.
Aquat Toxicol. 2016 Apr;173:53-62. doi: 10.1016/j.aquatox.2016.01.003. Epub 2016 Jan 23.
Exposure to prolonged environmental stress can have impacts on the cellular homeostasis of aquatic organisms. The current study employed two-dimensional electrophoresis (2-DE) to test whether exposure to impaired water quality conditions in the Sydney Harbour estuary has significantly altered the proteomes of the resident Sydney rock oyster (Saccostrea glomerata). Adult S. glomerata were sampled from four bays in the estuary. Each bay consisted of a "high-impact" site adjacent to point sources of chemical contamination (e.g., storm drains/canals or legacy hotspots) and a "low-impact" site located ∼5km away from point sources. A mixture of environmental stressors differed significantly between high- and low-impact sites. Specifically, PAHs, PCBs, tributyltin, Pb, and Zn were significantly elevated in oyster tissues from high-impact sites, together with depleted dissolved oxygen and low pH in the water column. A 2-DE proteomics analysis subsequently identified 238 protein spots across 24 2-DE gels, of which 27-50 spots differed significantly in relative intensity between high- and low-impact sites per bay. Twenty-five percent of the differential spots were identified in more than one bay. The identities of 80 protein spots were determined by mass spectrometry. HSP 70, PPIB, and radixin were the three most highly expressed differential proteins. Despite the largely unique proteomes evident in each bay, functional annotations revealed that half of the differentially expressed proteins fell into just two subcellular functional categories-energy metabolism and the cytoskeleton. These findings provide a framework to further investigate adaptation of cellular mechanisms to prolonged stress in S. glomerata.
长期暴露于环境压力下会对水生生物的细胞稳态产生影响。本研究采用二维电泳（2-DE）来测试悉尼港河口水质受损条件下的暴露是否显著改变了当地悉尼岩牡蛎（Saccostrea glomerata）的蛋白质组。成年S. glomerata取自河口的四个海湾。每个海湾都包括一个靠近化学污染源（如雨水排放口/运河或遗留热点）的“高影响”位点和一个距离污染源约5公里的“低影响”位点。高影响位点和低影响位点之间的环境压力源混合物存在显著差异。具体而言，高影响位点的牡蛎组织中多环芳烃、多氯联苯、三丁基锡、铅和锌显著升高，同时水柱中的溶解氧减少且pH值较低。随后的二维电泳蛋白质组学分析在24块二维电泳凝胶上共鉴定出238个蛋白质斑点，其中每个海湾的高影响位点和低影响位点之间有27 - 50个斑点的相对强度存在显著差异。25%的差异斑点在多个海湾中被鉴定出来。通过质谱法确定了80个蛋白质斑点的身份。热休克蛋白70、亲环蛋白B和根蛋白是三种表达量最高的差异蛋白。尽管每个海湾的蛋白质组在很大程度上是独特的，但功能注释显示，一半的差异表达蛋白仅属于两个亚细胞功能类别——能量代谢和细胞骨架。这些发现为进一步研究S. glomerata细胞机制对长期压力的适应性提供了框架。
