Identification of a proviral genome associated with avian myeloblastic leukemia

Abstract

We have identified and isolated a presumptive leukemogenic provirus from myeloblasts of a chicken in which leukemia had been induced by avian myeloblastosis virus (AMV). Leukemic myeloblasts isolated from peripheral blood or from converted yolk sac cultures of various strains of chickens, regardless of the endogenous proviral content or AMV pseudotype used for infection, contain an EcoRI 2.2-megadalton (MDaI) and a HindIII 2.6-MDal proviral fragment. A proviral genome flanked by chicken DNA sequences on either side and containing both the EcoRI 2.2-MDal and the HindIII 2.6-MDal fragments was inserted by molecular recombination into lambda phage Charon 4A and then cloned. This presumptive AMV proviral genome has a mass of approximately 4.9 MDal and contains terminal redundancies with respect to 3' viral RNA sequences.