FIG. 1.

Characteristics of TS expression in L. major. (A) Specific TS activity in lysates of three promastigote clones of L. major transfected with the TS gene of T. cruzi (L1, L2, and L3) and in one clone transfected with empty vector (Lv). The specific activity of TS in T. cruzi trypomastigotes (Tc) is shown for comparison. (B) Specific activity in medium conditioned by 5 days of growth of the clones in panel A. Error bars represent standard deviations. (C) Western blot analysis of TS in conditioned medium and lysates of L1 and Lv promastigotes and conditioned medium of T. cruzi trypomastigotes (Tc). TS was detected with MAb TCN-2. (D) Immunofluorescence analysis of TS in paraformaldehyde-fixed L1 and Lv promastigotes, using MAb TCN-2 as the primary antibody and a fluorescein isothiocyanate-labeled second antibody. A control IgG1 MAb (anti-p-azophenylarsonate) did not react with L1 promastigotes (not shown).