ELUCIDATION OF THE DNA SYNTHETIC CYCLE OF ENTAMOEBA HISTOLYTICA

我们开发了一种方法来研究溶组织内阿米巴和侵袭内阿米巴的DNA合成周期的流式细胞术（FCM）的基础上的制备程序，以减少高水平的天然荧光和非特异性吸附的荧光染料。我们将G_1、S和G_2相位建模为一系列重叠的高斯曲线。溶组织肠杆菌和侵袭肠杆菌均表现出G_1、S和G_2期比例，这与处于指数稳定生长期的真核细胞群一致。指数期溶组织肠球菌群体包含亚二倍体亚群，其质量比我们通过FCM估计的二倍体值（24 × 10^ gDNA/细胞）低约20%<-14>。指数期侵袭肠球菌群体包含亚二倍体亚群，其质量比通过FCM估计的二倍体值（30 × 10^ gDNA/细胞）低约6%<-14>。我们还建立了一种非致病性阿米巴--用1%的过氧化氢在4 ℃下处理24小时进行灭菌。检测并表征了在该培养体系中生长的阿米巴的DNA聚合酶活性。溶组织艾美耳球虫和舞毒蛾滋养体核提取物的DNA聚合酶活性在pH 2 ~ pH 6范围内较高，而在pH 8和pH 10范围内活性很低。

We developed a method to study the DNA synthetic cycles of Entamoeba histolytica and Entamoeba invadens by flow cytometry (FCM) based on a preparative procedure to reduce both high levels of natural fluorescence and non-specific adsorption of flurochromes. We modeled G_1, S,and G_2 phases as a series of overlapping Gaussian curves. Both E.histolytica and E,invadens displayd G_1, S,and G_2 proportions that are consistent with eukaryotic cell populations in exponential of stationary growth phase. Exponetial phase E.histolytica populations contained a hypodiploid subset with a mass of about 20% less than the diploid value which we estimate by FCM to be 24 x 10^<-14>gDNA/cell.Exponential phase E.invadens populations contained a hypodiploid subset with a mass of about 6% less than the diploid value which estimate by FCM to be 30 x 10^<-14>gDNA/cell.We developed also an axnic cultivation system for Entamoeba dispar which was nonpathogenic amoeba, by using newly developed BCSI-S medium in the presence of Crithidia fasciculata. sterilized by treating with 1% hydrogen peroxide for 24 hours at 4ﾟC.DNA polymerase activity of the ameba which was grown in this culture system, was detected and characterized. DNA polymerase activity was high at pH 2 to pH 6, but at pH 8 and 10 the activity was very low in nuclear extracts from both trophozoites of E.histolytica and E.dispar which were grown axnically.