Figure 3. Role of thymidine kinase (LinJ21.1450) in methotrexate susceptibility.

Growth curves in the presence of methotrexate were determined for L. infantum wild-type cells (lines with circles) and the Lin5FU500.3 mutant (lines with squares), each transfected either with an empty vector (pSP72αHYGα) (black circles and black squares respectively) or with a thymidine kinase expression construct (pSP72αHYGα-LinJ.21.1450) (white circles and white squares respectively). Average of three independent biological replicates. Transfection of TK in the mutant led to MTX susceptibility that was statistically different than the mock control (p<0.05).