{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,7]],"date-time":"2026-09-07T10:46:04Z","timestamp":1788777964021,"version":"build-2803163510"},"reference-count":40,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2022,7,5]],"date-time":"2022-07-05T00:00:00Z","timestamp":1656979200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100009619","name":"Japan Agency for Medical Research and Development","doi-asserted-by":"publisher","award":["20jm0210061"],"award-info":[{"award-number":["20jm0210061"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["18K07084"],"award-info":[{"award-number":["18K07084"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005865","name":"Mochida Memorial Foundation for Medical and Pharmaceutical Research","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100005865","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100008667","name":"SENSHIN Medical Research Foundation","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100008667","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cell. Infect. Microbiol."],"abstract":"<jats:p>The emergence and spread of drug-resistant <jats:italic>Plasmodium falciparum<\/jats:italic> have compromised antimalarial efficacy and threatened the global malaria elimination campaign using artemisinin combination therapies. The impacts of amino acid substitutions in antimalarial drug resistance-associated genes on drug susceptibility have been investigated; however, the effects of amplification of those genes remain unexplored due to the lack of robust genetic approaches. Here, we generated transgenic <jats:italic>P. falciparum<\/jats:italic> parasites with an additional copy of a drug resistance-associated gene using the highly efficient CRISPR\/Cas9 system and investigated their drug response. Insertion of a drug resistance-associated gene expression cassette in the genome resulted in a roughly twofold increase of mRNA levels of the target gene <jats:italic>mdr1<\/jats:italic>, which encodes multidrug resistance protein 1. The gene duplication event contributed to resistance to mefloquine, lumefantrine, and dihydroartemisinin, while the duplication of a genomic region encoding plasmepsin 2 and plasmepsin 3 did not affect resistance to antimalarial drugs, including piperaquine. We further demonstrated that <jats:italic>mdr1<\/jats:italic> mRNA expression levels are strongly associated with mefloquine resistance in several field-derived <jats:italic>P. falciparum<\/jats:italic> lines with various genetic backgrounds. This study provides compelling evidence that <jats:italic>mdr1<\/jats:italic> could serve as a molecular marker for the surveillance of mefloquine-resistant parasites. Long DNA integration into parasite genomes using the CRISPR\/Cas9 system provides a useful tool for the evaluation of the effect of copy number variation on drug response.<\/jats:p>","DOI":"10.3389\/fcimb.2022.915656","type":"journal-article","created":{"date-parts":[[2022,7,5]],"date-time":"2022-07-05T08:12:51Z","timestamp":1657008771000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":17,"title":["Evaluation of the Effect of Gene Duplication by Genome Editing on Drug Resistance in Plasmodium falciparum"],"prefix":"10.3389","volume":"12","author":[{"given":"Rie","family":"Kubota","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tomoko","family":"Ishino","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shiroh","family":"Iwanaga","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Naoaki","family":"Shinzawa","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2022,7,5]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"468","DOI":"10.1093\/infdis\/jix334","article-title":"Association of a Novel Mutation in the Plasmodium falciparum Chloroquine Resistance Transporter With Decreased Piperaquine Sensitivity","volume":"216","author":"Agrawal","year":"2017","journal-title":"J. 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