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

Abstract

SUMMARYChick embryos from the inbred Reaseheath I line of chickens contained a complement-fixing antigen which reacted in the COFAL test, whereas embryos from the inbred Reaseheath C line lacked the antigen. In cross-bred embryos between the I and C lines the antigen segregated in accordance with the hypothesis that the presence of the antigen was controlled by a single autosomal dominant gene. The antigen appeared to be identical to the groupspecific antigen of the avian leukosis-sarcoma group of viruses. No infectious virus was detected in I-line embryos, and the presence of the antigen was not correlated with response to the A and B subgroups of avian leukosis-sarcoma viruses. The possible relationship between the I-line antigen and viral groupspecific antigen is discussed.

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).…”

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

“…Expression of this genome could be controlled in such a way that gs antigen could be synthesized in the absence of full particles (8). Clear evidence of this exists in the chicken and mouse, where inheritance of expression of gs antigen in the absence of particles, as well as in their presence, is under control of a dominant gene (40,41).…”

Exogenous and endogenous leukosis virus genes ‐ A review

“…Partial expression of endogenous viruses has been found, and four major positive viral phenotypes have been seen as outlined in Table 1 (Robinson, 1978 Payne and Chubb (1968). Table 2 shows that when they mated an inbred line of the gs + chf + phenotype (Reaseheath line I) with one not expressing viral antigen (Reaseheath line C) and then made F t , backcross and second backcross matings to the line with the negative phenotype, segregation of phenotypes was clearly compatible with inheritance as a single-dominant gene.…”

“…Results in preliminary studies with several enzymes showed that the enzyme Sst I gave the simplest pattern, apparently cutting the viral genome only once very close to the left end so that one major band was visualised for each viral integration site. The size of the visualised fragment largely depends on the distance a Pi = Reaseheath line I; P 2 = Reaseheath line C (Payne and Chubb, 1968). b P] = RPRL line 7 2 ; P 2 = RPRL line 15 B (Crittenden etal, 1977).…”