Endogenous virus expression in chicken lines maintained at the Regional Poultry Research Laboratory

Abstract

Lines of chickens maintained at the Regional Poultry Research Laboratory (RPRL) and free of exogenous lymphoid leukosis virus (LLV) infection were assayed for expression of endogenous LLV. Embryos were assayed for the expression of infectious subgroup E LLVs, particulate RNA-directed DNA polymerase, antigens which could serve as envelope antigens for the envelope defective Bryan Rous sarcoma virus (chf), and the group-specific antigens of the leukosis-sarcoma virus group (gs). RPRL inbred lines 6 1, 6 3, 7 2, 100, and 15 B were similar in endogenous virus expression to the previously characterized Beltsville Agricultural Research Center inbred lines 6, 7 2, 100, and 15. The expression of endogenous LLV was characterized for the first time in three sublines of RPRL line 15 chickens. Line 15 1, was gs + chf +; line 15I 4, gs − chf +; and line 15I 5, gs − chf +. Some 15 1, and 15I 5 embryos produced infectious subgroup E, but all 15I 4 embryos produced infectious subgroup E virus. Two RPRL noninbred lines were also characterized Line P was segregating for subgroup E virus production and the gs + chf + phenotype. Line N was segregating for subgroup E virus production, the gs + chf + and gs − chf + phenotypes.