FIG 3.

Functional rescue of type II Toxoplasma gondii uracil auxotrophs. Approximately 100 tachyzoites of the Pru Δku80 Δompdc::HXGPRT (A and C) or Pru Δku80 Δompdc Δup::HXGPRT (B and D) strain were inoculated into a PFU assay in the absence of pyrimidine supplementation (A and B), in the presence of uracil supplementation (200 μM) (A and B), in the presence of uridine supplementation (200 μM) (C and D), or in the presence of cytidine supplementation (200 μM) (C and D) of the growth medium. The culture monolayer was stained 8 days later to reveal PFU and HFF monolayers.