Ca~(2+)在粟酒裂殖酵母细胞周期时相中的作用

以粟酒裂殖酵母(Schizosaccharomyces pombe)为研究材料，研究了Ca~(2+)在细胞周期时相中的作用。当外源Ca~(2+)浓度在0.5-20 mmol/L范围内，随Ca~(2+)浓度增加，细胞增殖速度加快，延滞期逐渐缩短。但SD-Ca（CaCl2省略）并不能终止Sch. pombe的细胞周期。采用缺氮对群体细胞进行同步化，并以EGTA 螯合培养介质中低浓度的Ca~(2+)，Sch. pombe 细胞增殖被完全抑制，细胞流式法测定结果表明：细胞周期被终止在G1期。分析认为Ca~(2+) 对Sch. pombe 细胞增殖是必不可少的，外源Ca~(2+)在G1期向S期转化过程中起着关键性的作用。

THE ROLE OF CALCIUM IN CELL CYCLE AND ITS PROGRESS IN SCHIZOSACCHAROMYCES POMBE

The roles of Ca~(2+) in cell cycle of Schizosaccharomyces pombe were studied. Exogenous Ca~(2+) in 0.5~20 mmol/L stimulated the proliferation of Sch. pombe mainly by increasing the growth rate and shortening the lag phase. The cell cycle could not be arrested by using SD-Ca which omitted CaCl2 and still contained contaminating calcium at a concentration of 0.022mmol/L. In addition, after Sch. pombe was cultured for 18h in medium that NH4+was omitted, most of cells were synchronous. When added NH4+,cell cycle was resumed. If NH4Cl and EGTA were added simultaneously, the cell cycle was arrested at G1 which determined by flow cytometry. This suggests that Ca~(2+) was necessary and important from G1 to S during cell cycle of Sch. pombe.