Fig. 4

Morphological evaluation of metacyclogenesis of WT parent and derived counterparts that were repeatedly exposed to MIL either in vitro (a–c) or in vivo (d–f). Repeated exposure to MIL in vitro resulted in significantly lower flagellum/cell body length ratios in 192 h-old and 216 h-old cultures. However, the cut-off value for metacyclogenesis was reached in 168 h-old cultures for both the WT and MIL-exposed strain. Repeated MIL exposure in vivo resulted in significantly higher flagellum/cell body length ratios in 168 h-old cultures with cut-off values for metacyclogenesisonly being reached in 192 h-old cultures. Results are expressed as the mean ratio ± SE and are based on the measurement of at least 50 promastigotes. *P < 0.05, ***P < 0.001