FIG. 2.

Viral glycoprotein detection in thymic lymphocytes. Western blot analysis of protein extracts from preleukemic thymic lymphocytes at different times after virus inoculation (A) or from thymic tumors and a tumor-derived cell line (B). C1 to C7, age-matched control mice that were inoculated with medium. M1 to M9, mice inoculated with virus at 2 to 4 days of age. Mink, protein extracts from productively infected mink epithelial cells used as markers for the mobility of the Env precursor polyprotein gPr80^env and SU gp70. The ratio of these proteins in productively infected cells is different from that in acutely infected cells, in which gPr80^env predominates (14). T1 to T7, thymic lymphomas induced by inoculation of MCF13 MLV. T8 to T11, spontaneous tumors arising in uninoculated mice. 92316, T-cell line derived from a thymic lymphoma induced by MCF247 MLV. MCF MLV Env was detected with the MAb 83A25 (5). α-Tubulin was detected as a control for loading.