Immunological Relationships of OMC-1, an Endogenous Virus of Owl Monkeys, with Mammalian and Avian Type C Viruses

The relationships between OMC-1, an endogenous oncovirus of owl monkey, and representatives of the three oncoviral genera have been investigated by radioimmunological techniques. The major structural protein of OMC-1 was shown to share antigenic determinants with the corresponding proteins of certain type C viruses of rodent, feline, and cervine origin. It was not possible to demonstrate antigenic cross-reactivity between OMC-1 and endogenous type C viruses of baboons. These findings argue that OMC-1 and baboon endogenous viruses do not represent direct descendants of an ancestor virus that became integrated within primates prior to the divergence of New and Old World species. A close antigenic relationship was established between the major structural proteins of OMC-1, an endogenous virus of deer (deer kidney virus), and avian reticuloendotheliosis viruses. These findings establish OMC-1 and deer kidney virus in the evolutionary lineage that may have led to the generation of avian reticuloendotheliosis virus, a group of oncogenic viruses capable of crossing the interclass barrier between mammals and birds.