During environmental stress, the vegetative cells of the facultative pathogenic amoeba Acanthamoeba castellanii reversibly differentiate into resistant dormant stages, namely, cysts or pseudocysts. The type of resistant stage depends on the nature and duration of the stressor. Cell differentiation is accompanied by changes in morphology and cellular metabolism. Moreover, cell differentiation is also expected to be closely linked to the regulation of the cell cycle and, thus, to cellular DNA content. While the existence of the resistant stages in A. castellanii is well known, there is no consensus regarding the relationship between differentiation and cell cycle progression. In the present work, we used flow cytometry analysis to explore the changes in the DNA content during Acanthamoeba encystation and pseudocyst formation. Our results strongly indicate that A. castellanii enters encystation from the G2 phase of the cell cycle. In contrast, differentiation into pseudocysts can begin in the G1 and G2 phases. In addition, we present a phylogenetic analysis and classification of the main cell cycle regulators, namely, cyclin-dependent kinases and cyclins that are found in the genome of A. castellanii.

在环境压力下，兼性致病性变形虫变形虫阿米巴虫的营养细胞可逆地分化为抗性休眠阶段，即囊肿或假囊肿。抗性阶段的类型取决于应激源的性质和持续时间。细胞分化伴随着形态和细胞代谢的变化。此外，还预期细胞分化与细胞周期的调节并因此与细胞DNA含量密切相关。尽管众所周知，卡斯特氏菌中存在抗性阶段，但关于分化与细胞周期进程之间的关系尚无共识。在目前的工作中，我们使用流式细胞仪分析来探索DNA含量的变化。棘阿米巴侵入和假性囊肿形成。我们的结果有力地表明，Castellanii从细胞周期的G2期进入整合。相反，分化成假性囊肿可以在G1和G2期开始。另外，我们介绍了主要细胞周期调节剂的系统发育分析和分类，即在卡斯特氏菌基因组中发现的细胞周期蛋白依赖性激酶和细胞周期蛋白。