Figure 6.

22A1 is essential for L. major promastigotes in culture. (A) Promastigotes were continuously cultivated in the presence or absence of GCV or nourseothricin (SAT) and percentages of GFP-high cells were determined by flow cytometry for each passage. Error bars represent standard deviations from three biological replicates. (B–D) After 6 passages, single clones were isolated from 22A1^−/− +pXNG4-22A1 cells grown in the presence of GCV by serial dilution and allowed to proliferate. Flow cytometry analyses were performed on the original 22A1^−/− +pXNG4-22A1 GCV population (B) and two representative clones ((C) from GFP-low and (D) from GFP-high). In (B–D), percentages of GFP-high cells were indicated as R3. (E) Promastigotes were inoculated at 1.0 × 10⁵ cells/mL in the presence or absence of GCV or SAT and culture densities were determined daily (***: p < 0.001).