PDF(Pubmed)
Abstract：
Tardigrades are renowned for their ability to survive a wide array of environmental stressors. In particular, tardigrades can curl in on themselves while losing a significant proportion of their internal water content to form a structure referred to as a tun. In surviving varying conditions, tardigrades undergo distinct morphological transformations that could indicate different mechanisms of stress sensing and tolerance specific to the stress condition. Methods to effectively distinguish between morphological transformations, including between tuns induced by different stress conditions, are lacking. Herein, an approach for discriminating between tardigrade morphological states is developed and utilized to compare sucrose- and CaCl2-induced tuns, using the model species Hypsibius exemplaris. A novel approach of shadow imaging with confocal laser scanning microscopy enabled production of three-dimensional renderings of Hys. exemplaris in various physiological states resulting in volume measurements. Combining these measurements with qualitative morphological analysis using scanning electron microscopy revealed that sucrose- and CaCl2-induced tuns have distinct morphologies, including differences in the amount of water expelled during tun formation. Further, varying the concentration of the applied stressor did not affect the amount of water lost, pointing towards water expulsion by Hys. exemplaris being a controlled process that is adapted to the specific stressors.
摘要：
缓步以其在各种环境压力下生存的能力而闻名。特别是,缓流可以在自身上卷曲，同时失去其内部水分的很大一部分，以形成称为tun的结构。在不同的条件下生存，缓行经历不同的形态转变，这可能表明特定于应力条件的应力感应和耐受性的不同机制。有效区分形态变换的方法，包括由不同压力条件引起的金枪鱼之间，缺乏。在这里，开发了一种区分缓行形态状态的方法，并用于比较蔗糖和CaCl2诱导的tuns，使用模型物种Hypsibius示例。使用共聚焦激光扫描显微镜进行阴影成像的新颖方法使Hys的三维渲染得以产生。在各种生理状态下进行体积测量。将这些测量与使用扫描电子显微镜进行的定性形态分析相结合，表明蔗糖和CaCl2诱导的tuns具有不同的形态，包括tun形成过程中排出的水量的差异。Further,改变施加的应激源的浓度不会影响损失的水量，指向Hys的水驱逐。示例是适应特定压力源的受控过程。
