Figure 2.

Growth and susceptibility curves of L. major lineages exposed to ionizing radiation. The graphs display how the L. major cell population of the three lineages evolved after the exposure to ionizing radiation (IR) and the effects of the addition of 5 mM caffeine over that evolution. WT lineage, not treated with caffeine (WT CAF-): empty circles; episome vector control lineage, not treated with caffeine (“pXG1 CAF-”): empty triangles; LmjEXO1 overexpressor lineage, not treated with caffeine (“EXO1 CAF-”): empty squares; wild type lineage, treated with caffeine (WT CAF+): full circles; episome vector control lineage, treated with caffeine (“pXG1 CAF+”): full triangles; LmjEXO1 overexpressor lineage, treated with caffeine (“EXO1 CAF+”): full squares. The parasites were exposed to 500 Gy of gamma radiation and counted daily with hemocytometer. The data were normalized and presented as mean ± standard error for two independent experiments, each one performed in triplicate. The point 0% represented the initial parasite population, right before the irradiation (the dashed line along the graphs). Under that line (negative values), the data points represent the percentage of cell death from the initial starting point, i.e., 100% of the lower part of the graph means the complete death of initial parasite population. The superior part of the graph (positive values) represent parasite population growth, so that 100% means maximum growth, defined as the maximum quantity of parasites reached by each lineage not exposed to IR (0 Gy).