Micromorphology of cytoplasmic nucleoprotein complexes harboring an extrachromosomal DNA closely related to avian myeloblastosis virus core-bound DNA

AbstractNucleoprotein (NP) complexes constituting the three basic components (A, B, C) of the postmicrosomal sediment (POMS) of chicken leukemic myeloblasts (CHLMs) which contain extrachromosomal DNA closely related to avian myeloblastosis virus DNA were analyzed electron microscopically. It was shown that these NP complexes resemble micromorphologically, depending on the origin of their POMS components, NP structures involved in three successive stages of early DNA synthesis. Nucleic acids harbored in these NP complexes exhibited micromorphological features typical for replicative structures. It was confirmed electron microscopically that the extrachromosomal DNA of CHLMs replicative in nature and of three length classes is organized into special NP complexes, each of which, as demonstrated, represents a unique reaction machinery of early DNA synthesis