Application of a ciliate, Paramecium, as a sensor for a chemical substances

纤毛虫具有独特的细胞功能，如纤毛反转、胞体收缩、胞吐等，这些细胞功能是由化学物质等多种刺激物的接触引起的。本文以尾草履虫（Paramecium caudatum）细胞为研究对象，研究了细胞内钙离子浓度与细胞功能之间的关系，并利用苦味酸对尾草履虫细胞表面进行处理，结果表明，尾草履虫通过长时间的钙瞬变（> 3s）释放出胞囊。在应用乙醇的情况下，草履虫排出囊泡。在这种情况下，钙瞬变很短（<1 s）。这些结果表明，细胞内钙的行为依赖于化学刺激。接下来，我们将钙荧光指示剂钙绿色注射到纤毛Didiniunnasutum中，观察纤毛自发性纤毛逆转过程中纤毛内钙的水平。In D.鼻骨，钙上升整个长度的纤毛伴随着纤毛逆转。这些结果有力地表明，纤毛逆转的钙内流网站分布在整个纤毛。

Ciliate have characteristic cell functions, such as ciliary reversal, contraction of cell body, exocytosis and so on. These cell functions are induced by a contact of several stimuli such as chemical substances. It is known that these cell functions are controlled by intracellular calcium level.In this study, we investigate the relationship between the cell functions and intracellular calcium level in order to apply ciliates as a sensor for chemical substances.In response to the application of picric acid to the cell surface of a Paramecium caudatum cell, the Paramecium discharged trichocysts through the long term calcium transient (>3 s). In the case when ethanol was applied, the Paramecium discharged trichocysts. In this case, the calcium transient was short (<1 s). These results demonstrate that the intracellular calcium behavior is depending on the chemical stimuli.Next, we injected the fluorescent calcium indicator Calcium Green into a ciliate Didiniun nasutum and observed the intra-ciliary calcium level during spontaneous ciliary reversal of the cirri. In D. nasutum, calcium rose throughout the length of the cilia accompanied by ciliary reversal. These results strongly suggest that calcium influx sites for ciliary reversal are distributed throughout the cilium.