RT Journal Article SR Electronic(1) A1 Ignjatovic, JagodinaYR 1988 T1 Isolation of a Variant Endogenous Avian Leukosis Virus: Non-productive Exogenous Infection with Endogenous Viruses Containing p27 and p27° JF Journal of General Virology, VO 69 IS 3 SP 641 OP 649 DO https://doi.org/10.1099/0022-1317-69-3-641 PB Microbiology Society, SN 1465-2099, AB Summary Ten replication-competent endogenous avian leukosis viruses (ALVs) with subgroup E specificity were isolated from six commercial chicken lines of mixed breed. All the ALVs isolated belonged to a variant class of endogenous viruses with a major group-specific antigen, p27, identical in size to that of exogenous viruses and different from the p27° of endogenous viruses isolated from White Leghorn chickens. It was possible to infect chickens exogenously with endogenous viruses (containing p27) and with Rous-associated virus type 0 (containing p27°) but infection was non-productive. Congenital transmission and shedding did not occur in chickens infected with endogenous viruses containing p27° or in chickens infected with endogenous viruses containing p27. Restriction of endogenous virus replication in some tissues (heart, spleen and meconia) of viraemic chickens was observed suggesting that exogenous infection of chickens with endogenous viruses differs from an infection with exogenous ALVs., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-69-3-641