Fig. 1. Experimental scheme of the functional screening approach used to identify a drug-resistance gene from a single drug-resistant P. falciparum strain.

High-coverage genomic libraries were generated in drug-sensitive parasites (blue) from drug-resistant strains (yellow) using the centromere plasmid pFCENv1. The recipient parasite acquired drug resistance due to the introduction of the drug-resistance gene; thus, it survived during drug screening. The DNA fragment inserted in pFCENv1 was recovered from the surviving parasites, and its sequence was determined using genome-walking analysis.