Ethanol Affects Endocytosis and Proliferation of Tetrahymena pyriformis GL and Promotes Encystment

Jytte R. Nilsson

《Acta Protozoologica》 44卷4期 (2005/12) Pp. 293-299

並列摘要

Exponentially multiplying cells were exposed to 0.25-2.5% ethanol (v/v) in the growth (PP) medium. Acute exposure was studied during a 6-h period, i.e. two normal cell generations, whereas chronic exposure was determined after 24 h, or more, in ethanol. The effects of low ethanol concentrations (0.25-1.0%) were modest as the rate of endocytosis was almost normal and the rate of cell proliferation only slightly decreased. In high concentrations (＞1.0%) the acute effects of ethanol were dose- and time-dependent with respect to a lag period before proliferation resumed at a decreased rate and to the capacity of cells to form food vacuoles. After 24 h in the low ethanol concentrations the cells appeared to have adapted. In the high concentrations, however, chronic effects of ethanol were a much decreased rate of endocytosis and a distinct separation of the cells into two populations: normal sized cells and small mostly round cells. The small round cells were lying at the bottom af the culture dish, motionless or slowly moving with no visible oral structure but with somatic cilia, some cells lacked cilia and had a refractive outline or layered wall structure. These cells looked like precystic stages among which a few resting cysts were seen with pores in the cyst wall. Promotion of encystment in Tetrahymena pyriformis is surprising as the phenomenon is not considered a feature of this organism.

並列關鍵字

encystment ； ethanol ； growth ； phagocytosis ； Tetrahymena pyriformis GL-C