[Ultrastructure of the retrovirus of human myeloma cells]

Extracellular population of oncovirus of continuous human myeloma RPM18226 cells contains type D virions in addition to morphological types of A and C particles. Nucleoids of type D oncoviruses are encapsulated. Peculiar contacts morphologically similar to slit-like links between eucaryots were found between adjacent extracellular RPM18226V virions. Viral type A cores are formed both in any part of the cell hyaloplasm and on its surface. Comparative study of the ultrastructure of RPM18226V and some other retroviruses showed RPM18226V to be structurally and morphogenetically identical with squirrel monkey virus and, accordingly, should be classified in the group of type D oncoviruses (Retroviridae family, Oncoviridae subfamily, genus Oncovirus D).