[The types of virus-specific structures in cells of human origin producing oncornaviruses].

In the cell cytoplasm of human tissue cultures Detroit-6 and AO which produce B type oncorna-virus, two types of virus-specific structures were revealed. Structures of type I were aggregated fibrils of 3 and 6 nm diametre. Structures of type II were nucleoids of A-particles of 70-80 nm diametre. They were rather well separated from cell components by centrifugation sucrose density gradient and repeated centrifugation in the sucrose concentration gradient. Fibrils were found in the density regions of the equilibrium gradient of 1.26 and 1.19 g/cm3, whereas A-particles were detected in the sones of the density of 1.29 and 1.23-124 g/cm3. Their sedimentation coefficients in the sucrose concentration gradients were about 150S and 250S, respectively. From both structure types similar RNA classes were extracted sedimenting in 60S, 45S and 35S regions (sucrose concentration gradient). In addition, 20S RNA was found within the 150S structures. Both structures sa. However, hydridization degree of RNA isolated from both structures with DNA synthesized enzymatically on extracellular various (DNA I) and A-particles (DNA II) was different. With DNA-I, 50-80% of RNA isolated from the type I structures and less than 20% of RNA extracted from the type II structures were hybridized. At the same time, strictly opposite situation (50-80% of RNA II and 20% of RNA I) was observed for DNA-II. These data show lack of genetic connection between these types of cytoplasmic structures and possible role of type I structures in reproduction of oncorna-virus type B.