Some biological properties of two new avian sarcoma viruses

P C Balduzzi, M F Notter, H R Morgan, M Shibuya
1981 Journal of Virology  
The new avian retroviruses UR1 and UR2 were isolated from spontaneous tumors of chickens by cocultivation of tumor material with susceptible chicken embryo fibroblasts. In vitro, UR1 induced formation of small foci of round and fusiform cells. On the other hand, cells infected by UR2 assumed an extremely elongated morphology. In vivo, both viruses induced fibrosarcomas and myxosarcomas with short latencies. Infectivity assays with and without mitomycin C showed that both viruses were defective
more » ... ses were defective for replication, but transformed nonproducing cell clones were obtained only with URL. URl-infected transformed nonproducing clones did not release particles detectable by reverse transcriptase assays, and fusion of transformed nonproducing cells with quail cells chronically infected with Rous sarcoma virus (a Bryan strain) failed to rescue infectious virus. This suggested that UR1 does not code for functional envelope glycoproteins. In this regard, UR1 appeared to be similar to Fujinami, PRCII, and Y73 viruses. The helper viruses of partially purified stocks of UR1 and UR2 appeared to belong to subgroup A, but these helper viruses were distinguishable from each other, as shown by host range experiments and neutralization tests. Hybridization studies with DNA complementary to the src gene of Rous sarcoma virus and RNAs extracted from both UR1 and UR2 showed no homology between the genomes of the new isolates and the transforming gene of Rous sarcoma virus. ens in the United States in 1963 and 1969. These viruses, designated UR1 and UR2, are defective in replication and appear to contain transforming insertions unrelated to src. MATERIALS AND METHODS Viruses. The origin and preparation of URI and UR2 are described below. Other viruses used in this investigation were Rous-associated virus-i and RAV-3, two subgroup A leukosis viruses (originally from P. K. Vogt), RAV-6 (subgroup B; kindly provided by R. Dougherty), RAV-7 (subgroup C; a gift 268 on May 10, 2020 by guest
doi:10.1128/jvi.40.1.268-275.1981 fatcat:cpf4mmvaazc7lcuehtt6c5ezty