Abstract：
Environmental pollutants are recognized as one of the major concerns for public health. The free-living nematode Caenorhabditis elegans are widely used to evaluate the toxicity of environmental contaminants in biomonitoring researches. In the present study, a new transgenic strain, rps-30-/- ;RFP-RPS-30UbL was generated, with constitutively active rps-30 promoter used to control the expression of RFP-RPS-30UbL fusion protein. We found RFP-RPS-30UbL would accumulate to form \'rod-like\' structures, when worms were exposed to environmental contaminants, including Cd, Hg, Pb, As, Paraquat and Dichlorvos. The number of the \'rod-like\' structures was induced by environmental contaminants in a concentration- and time-dependent manner. The \'rod-like\' structure formation could be detectable in response to the concentration of each contaminant as low as 24-h LC50 × 10-7 , and the detectable time could be within 2 h. Detecting the transcription and expression levels of RFP-RPS-30UbL in worms exposed to different kinds of environmental contaminants showed that the expression level of RFP-RPS-30UbL was not regulated by environmental contaminants, and the number differences of \'rod-like\' structures were just due to the morphological change of RFP-RPS-30UbL from dispersion to accumulation induced by environmental contaminants. In addition, this transgenic strain was developed in rps-30-/- homozygous worm, which was a longevity strain. Detection of lifespan and brood size showed that rps-30-/- ;RFP-RPS-30UbL transgenic worm was more suitable to be cultured and used further than N2;GFP-RPS-30UbL , for expressing RPS-30UbL in wild type N2 worms shortened the lifespan and deceased the brood size. Therefore, rps-30-/- ;RFP-RPS-30UbL transgenic worm might play a potential role in versatile environmental biomonitoring, with the advantage of not only the convenient and quick fluorescence-based reporter assay, but also the quantificational evaluation of the toxicities of environmental contaminants using \'rod-like\' structures with high sensitivity, off-limited the expression level of the reporter protein.
摘要：
环境污染物被认为是公共卫生的主要问题之一。在生物监测研究中，秀丽隐杆线虫被广泛用于评估环境污染物的毒性。在本研究中,一种新的转基因菌株，rps-30-/-;生成RFP-RPS-30ubL,具有组成型活性的rps-30启动子用于控制RFP-RPS-30UbL融合蛋白的表达。我们发现RFP-RPS-30UbL会积聚形成“杆状”结构，当蠕虫暴露于环境污染物时，包括Cd,Hg,Pb,As,百草枯和敌敌畏。“杆状”结构的数量是由环境污染物以浓度和时间依赖性方式引起的。响应于每种污染物的浓度低至24小时LC50×10-7，检测时间可在2h内。检测暴露于不同环境污染物的蠕虫中RFP-RPS-30UbL的转录和表达水平表明，RFP-RPS-30UbL的表达水平不受环境污染物的调节，棒状结构的数量差异仅是由于环境污染物引起的RFP-RPS-30UbL从分散到积累的形态变化。此外,该转基因菌株是在rps-30-/-纯合蠕虫中开发的，这是长寿的压力。寿命和幼虫大小的检测表明，rps-30-/-;RFP-RPS-30UbL转基因蠕虫比N2更适合培养和进一步使用;GFP-RPS-30UbL，在野生型N2蠕虫中表达RPS-30UbL缩短了寿命并减少了育苗的大小。因此,rps-30-/-;RFP-RPS-30UbL转基因蠕虫可能在多功能环境生物监测中发挥潜在作用，不仅具有方便快捷的基于荧光的报告测定的优点，而且还使用高灵敏度的“杆状”结构对环境污染物的毒性进行定量评估，限制报告蛋白的表达水平。
