Isolation and propagation of a virus from a spontaneous mammary carcinoma of a rhesus monkey.

Virus particles morphologically similar to the known oncogenic RNA-type viruses have been isolated and cultured from a spontaneous mammary carcinoma of a rhesus monkey. The virus was initially isolated by cocultivation of tumor tis sues with monkey embryonic cell cultures but was later found to be transmissible as a cell-free filtrate. The virus is approximately 110 m^t in diameter and has a buoyant density between 1.14 and 1.16. Preliminary hostrange studies thus far have shown the virus to replicate in rhesus monkey mixed embryo, embryonic lung, chimpanzee lung, and human mixed embryo cell cultures, and in an estab lished human leukocyte culture, NC-37. Virus did not replicate in hamster kidney, mouse bone marrow, rhesus or African green monkey kidney cells, or baboon or chimpanzee leuko cyte cultures.