Comparative studies on the cellular response to chemical loading in unicellular eucaryote, Euglena gracilis, strains Z and SMZ

抄録

Euglena gracilis, a single cell organism with plant and animal characteristics is useful tool in studying cellular response to various chemical stresses. E. gracilis strains Z and achlorophyllous mutant SMZ were used in this study. In elucidation of the mechanism of the cellular response to the chemical loading in E. gracilis, we hypothesized that G-protein and phosphatidylinositol biphosphate mediated signal transduction pathway participates in the cellular response of E. gracilis. Then, changes of their morphology, deflagellation and the intracellular calcium level by tributyltin chloride (TBTCl) were compared concerning several calcium agonists and antagonists. By 50μM of TBTCl loading on Z strain, a lost of cell motility, morphological change, deflagellation and increase of intracellular calcium level were observed, however, halt of cell motility without distinctive morphological change and a behavior of intracellular calcium level were observed in SMZ strain. Interestingly, the response to a concentration jump of inositol 1, 4, 5-trisphosphate (10 nM) loading in Z and SMZ strain was not the same, suggesting some difference in inositol 1, 4, 5-trisphosphate mediated signal transduction system.