In utero tumor induction by murine sarcoma virus (moloney) in the rat. I. Biological characteristics

Abstract

Female R rats mated with an R male and inoculated in utero, after fetectomy, with murine sarcoma virus (Moloney), developed tumors. These tumors originated in the uterus and were of fetal origin. Intravenous or intraperitoneal injection of the virus induced similar tumors. Infectious virus could not be isolated from the tumor cells kept as transplantable lines or cultured in vitro. However, the presence of the MSV genome could be demonstrated by a direct rescue test. In non‐pregnant rats treated in the same way no neoplasms were recorded. The results are discussed in the light of current theories on the special immunological fetal‐maternal relationship.