Fig 5.  Immunofluorescence labeling of T. gondii shows that PFUS I-2 antibody is specific for PRP1 and indicates that PRP1 is associated with secretory organelles.

A-F Micrographs of isolated tachyzoites labeled with I-2 peptide antibody before and after competition with specific peptides (A, C, E).  Immunofluorescent images (A) I-2 antibody labeling.  (C) I-2 antibody competed with PFUS I-2 peptide (0.1 mM) from Paramecium and (E) competed with I-2 PRP1 peptide (4 nM) from T. gondii.  (B, D, F), Nomarski of (A, C, E).

G-N Co-localization of organelle-specific antibodies and PRP1 to the apical end of tachyzoites (I, N).  (G) ROP2,3,4 antibody (content of rhoptry).  (H) I-2 antibody (PRP1).  (I) Overlap indicated in yellow in the superimposed image.  (J) Nomarski image of the cell shown in (G-I).  (K)  MIC3 antibody (content of microneme).  (L) I-2 antibody (PRP1).  (N) Overlap indicated in yellow in the superimposed image.  (M) Nomarski image of the cell shown in (K-N).

Scale bars in (A-F) represent 5 mm and 2 mm in (G-M).