Table 1. P_i uptake by parental, ΔTgPiT and ΔTgPiT::PiT parasites Intracellular parasites were cultivated for 24 h in P_i-depleted DMEM with 1% FBS prior to the phosphate uptake assay, which was performed as described in legend of Fig 1, in a P_i-depleted reaction medium at pH 7.4 containing 100 μM ³²P_i in the presence of 140 mM NaCl or choline chloride (ChCl) for energized and unenergized phosphate uptake conditions, respectively, at the indicated times.

Conditions	Pi uptake (fmol Pi x (106 cells)-1 (mean ± SEM, n = 3)
2 min, NaCl a. Parental b. ΔTgPiT c. ΔTgPiT::PiT	79.2 ± 40.5 6.3 ± 2.7 79.9 ± 48.3
2 min, ChCl a’. Parental b’. ΔTgPiT c’. ΔTgPiT::PiT	24.9 ± 14.2 4.0 ± 1.6 6.2 ± 2.4
10 min, NaCl d. Parental e. ΔTgPiT f. ΔTgPiT::PiT	525.6 ± 123.6 86.9 ± 36.9 274.0 ± 57.9
10 min, ChCl d’. Parental e’. ΔTgPiT f’. ΔTgPiT::PiT	118.7 ± 58.6 62.0 ± 27.6 171.2 ± 21.9

The p values are p<0.015 for conditions f versus f’; p<0.004 for conditions a versus a’ and c versus c’; p<0.0001 for conditions a versus b, d versus e and d versus d’. The p values are not significant for conditions b versus b’ and e versus e’ (unpaired Student’s t-test).