The prevalence of C-type RNA tumor-virus gs antigen and infectious virion expression was determined at various ages throughout the life span of the BALBIcCr mouse.

Strain BALB/c mice harbor at least two host range variants of marine leukemia virus. One variant, which is host-cell tropic, is the predominant isolate from neoplastic tissues and produced lymphoreticular neoplasms when injected into BALB/c newborn mice. A second variant, whicht is isolated throughout life, grows poorly in host embryonic cells in culture and was not associated with lymphoreticular neoplasm induction when injected into newborn BALB/c mice.

No abstract

No abstract

No abstract