Abstract: |
This chapter discusses the murine mammary tumor virus (MuMTV), a complex enveloped RNA virus, which is the only virus known to be the etiological agent of spontaneous mammary tumors in mice. MuMTV can be transmitted by two key routes: (1) congenital infection of suckling mice by milk-borne exogenous virus and (2 ) genetically as an endogenous provirus. Exogenous MuMTV causes mammary adenocarcinomas in infected females at a high incidence between 7 and 9 months of age, and large quantities of MuMTV produced early in the mammary glands of these mice are expressed in their milk. Their mammary tumor cells also produce large quantities of MuMTV. Understanding of the synthesis and processing of the structural polypeptides of MuMTV is fairly comprehensive. Studies on the existence of pits on the viral surface and the organization of the viral core may lead to a greater understanding of the intriguing structural features of MuMTV. © 1987, Elsevier B.V. All rights reserved. |