Identification of the avian myeloblastosis virus genome. I. Identification of restriction endonuclease fragments associated with acute myeloblastic leukemia.

The proviral DNA of chicken peripheral blood leukemic myeloblasts was analyzed by restriction endonuclease digestion and Southern blotting. Two restriction endonuclease-generated fragments, an EcoRI 2.2-megadalton (Md) and a HindIII 2.6-Md fragment, were present upon enzyme cleavage of all leukemic myeloblast DNA preparations in addition to endogenous or helper-specific fragments. Neither of these fragments was derived from viral DNA of the two known myeloblastosis-associated viruses (MAV-1 and MAV-2). In contrast, DNA similarly treated from the erythrocytes of leukemic chickens showed only small amounts of the two avian myeloblastosis virus-specific fragments, whereas the helper virus-specific fragments were present in the amount seen in MAV-producing chicken embryo fibroblasts. The appearance of the EcoRI 2.2-Md and HindIII 2.6-Md specific fragments in all leukemic myeloblast DNA preparations indicates they are presumably part of the leukemogenic genome that must be present to induce acute myeloblastic leukemia.