Identification and Structure Analysis of Endogenous Proviral Sequences in a Brown Leghorn Chicken Strain

In a Brown Leghorn chicken strain, four endogenous proviral loci have been identified. The DNA mapping data show strong homology between their structures and that of the Rous-associated virus O (RAV-O) genome. Two of them seem similar to ev3 and ev6 loci previously described in White Leghorn chickens; the two others are unknown in White Leghorns. Using DNA amplification methods, envelope genes of these endogenous viral structures have been partially sequenced. The results demonstrate that subgroup-specific sequences of the endogenous loci were largely homologous with those of RAV-O.