A schematic representation of the method for the identification of drug-resistance genes from the PAC library. The genomic DNA isolated from drug-resistant parasites is partially digested with a restriction enzyme, and the DNA fragments ranging from 10–50 kb are then incorporated into the PAC. Subsequently, the PAC that includes the DNA fragments is linearized by digestion with PmeI, and the constructed PAC library is directly introduced into drug-sensitive parasites by electroporation. Parasites that acquire resistance via the PAC (including the drug-resistance gene) are selected by drug screening in vivo. Finally, the drug-resistance genes are identified by analyzing the DNA fragments in the PAC from the selected parasites.
