Experimental infection of sheep and goat with bovine leukemia virus: localization of proviral information on the target cells.

Bovine leukemia virus (BLV) proviral integration was studied in the DNA from circulating leucocytes or tumor cells of sheep and goats experimentally infected with BLV. Southern blot analysis of infected cell DNA for BLV proviral sequences indicate that: (1) the provirus may be found as unintegrated molecules in the circulating leucocytes of infected sheep; (2) the provirus is integrated at many sites in the genome of the leucocytes of infected goats and occasionally in infected sheep; (3) the provirus is present at only a few sites in the DNA of sheep or goat tumor cell clones. A second case of goat lymphosarcoma is also reported.