Abstract: | Electron microscope studies of spherical intranuclear inclusions (II) of Entamoeba histolytica trophozoites of two strains, which were maintained in polyxenous culture for different periods of time, were carried out. Data on the number of II in different individuals and in different strains are given. The structure of II whose external layer consists of electron dense material and resembles morphologically peripheral chromatin of the ameba's nucleus, an analogy of nucleolus chromatin of cells of other eucariots, is considered. Inside this layer some II have annular filaments about 9 nm thick rolled up spherically around the central zone of II. Comparison of results obtained and literary data suggests that the dynamic structure of II in question reflects a number of biosynthetic processes on the basis of annular extrachromosomal DNA of exogenic origin. |