FIG. 2.

Evolution of lymphocyte counts in BLV-infected sheep. Sheep were infected with the pBLVTax106+293 recombinant (TAX) (animals 103, 104, 296, and 480) or with viruses exhibiting wild-type (WT) behavior during pathogenesis (plasmid pBLVIX in sheep 8, 11, 247, 292, and 293; pBLV344 in 235; and pBLVgag150 in 175). Blood samples were extracted at regular intervals (routinely every month), and the number of leukocytes per microliter was determined by using a Coulter counter ZN. The lymphocyte counts (in parentheses) were deduced from these numbers after microscopic determination of the blood formula.