Live-cell epifluorescence microscopy of P. falciparum transfected using pGlux.1 vector for episomal expression of GFP fused to the two Pf CysRS mRNA isoforms: Pf CysRS-A1–153GFP (A) and Pf CysRS-B1–70GFP (B) in live cells. In (A), both parasites are early trophozoite stage, and localization of GFP is to a single punctum, consistent with the size and position of the apicoplast. The red blood cell (RBC) and the parasite (P) are indicated. (B) An early trophozoite (top panels) and late trophozoite (bottom panels) with GFP dispersed throughout the cytosol. (C) Immunofluorescence assays of the parasites indicated, Pf CysRS-A1–153GFP (top panels) and Pf CysRS-B1–70GFP (bottom panels), using antibodies against GFP and ACP, an apicoplast marker. The Pf CysRS-A1–153GFP signal specifically co-localizes with the apicoplast marker, whereas the Pf CysRS-B1–70GFP signal is distributed throughout the cytosol. For (A)–(C), all scale bars indicate 5 μm.

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