Virus particles and viral antigens in chicken tissues free of infectious avian leukosis virus.

Studies on the Nature and Genetic Control of an Antigen in Normal Chick Embryos which Reacts in the COFAL Test

“…In this study we found no difference between the natural antigen, virusinduced antigen, and gs antigen derived from fractionated avian myeloblastosis virus. This is in agreement with Dougherty et al (1967), who stated that their natural antigen appeared to be identical to virus antigen in immunodiffusion tests in agar gel. In contrast, Furminger & Beale (I968) reported that an antigen in chick embryos which reacted in the COFAL test differed from gs antigen in immunodiffusion tests.…”

“…The four main possibilities raised by Dougherty & Di Stefano (1966) and Dougherty et al (1967) warrant further consideration in the light of our findings.…”

Group-Specific Antigens of RNA Tumor Viruses as Markers for Subinfectious Expression of the RNA Virus Genome

“…The presence of gs antigen in embryonic tissues was not dependent on the presence of infectious virus, although it was always present when infectious virus was detected. Similar findings of gs antigen have been made in chickens and hamsters by the same techniques (6,23,27), by use of specific antisera to gs antigen.…”

Widespread Presence, in Chickens, of DNA Complementary to the RNA Genome of Avian Leukosis Viruses

“…(i) The presence of an antigen that crossreacts with antibody against the ALV group-specific antigen (13); (ii) the synthesis of a small number of apparently noninfectious C-type virions in the pancreas and liver of leukosis-free embryos (15) and in the pancreas and ovary of healthy adult hens (16); (iii) the helper function without which RSV(0) cannot replicate (13); (iv) the production of RAV (Rous-associated virus)-60 that is induced by infection with RSV (17), and probably by the same mechanism, the often noted. contamination of pure ALV stocks by other leukosis viruses; (v) by Dr. R. Friis (0 = no gs-antigen detected).…”