Bioactivity of Male (Sperm Transmitted) Mouse Mammary Tumor Virus as Influenced by Donor,Recipient and Age at Treatment 1

Abstract

The sperm collected from mammary tumor virus (MTV)-carrying mice (C3H, BALB/cfC3H, BALB/cfRIII and RIII) was separately tested for mammary tumor-inducing activity in (BALB/c × C3Hf)F₁, (BALB/c × RIIIf)F₁, and BALB/c female recipients by i.p. injection of 0.1 ml of the sperm at 1–2 weeks or at 3 months of age. A total of 551 recipients was observed, including control mice. The results may be summarized as follows: 1) mammary tumor incidence in experiments with or without histocompatibility between sperm donor and recipient is the same; 2) bioactivity is related to the type of MTV (C3H, RIII) and to the type of recipient, not to the sperm donor; 3) the activity of RIII MTV released in the sperm appears to be less influenced by the age of recipients than is that of C3H MTV; 4) BALB/c recipients are more susceptible to C3H than to RIII sperm-released MTV; 5) (BALB/c × RIIIf)F₁ hybrids are resistant to sperm-released MTV, especially to C3H MTV infection, and show a 34% incidence of late spontaneous lymphomas inherited by the RIIIf male parent; 6) (BALB/c × C3Hf)F₁ hybrids are susceptible to both C3H and RIII sperm-released MTV and show a 30% incidence of late spontaneous mammary tumors due to genetic transmission of MTV by the C3Hf male parent.