BLV-LB virus-specific sequences in cattle with spontaneous and experimentally induced leukemia

Poly(A)-containing RNAs were extracted directly from the culture fluid of BLV-producing continuous and short-term lymphocyte cultures. The abovesaid poly(A)-RNAs were used as a template to synthesize complementary [3H]DNA (BLV cDNA). BLV cDNA possessed a high degree of homology to poly(A)-RNA isolated directly from the blood plasma of a leukemic animal. In contrast of leukemic cattle BLV-related sequences in white blood cells of normal animals were absent. Leukemic cells of cattle with both, spontaneous and experimentally induced leukemia contained bovine leukemia virus sequences in their genomes.