Transformation of Plasmodium falciparum malaria parasites by homologous integration of plasmids that confer resistance to pyrimethamine Academic Article Article uri icon


MeSH Major

  • Antigenic Variation
  • Antigens, Protozoan
  • Malaria, Falciparum
  • Plasmodium falciparum
  • Protozoan Proteins


  • Plasmodium falciparum malaria parasites were transformed with plasmids containing P. falciparum or Toxoplasma gondii dihydrofolate reductase-thymidylate synthase (dhfr-ts) coding sequences that confer resistance to pyrimethamine. Under pyrimethamine pressure, transformed parasites were obtained that maintained the transfected plasmids as unrearranged episomes for several weeks. These parasite populations were replaced after 2 to 3 months by parasites that had incorporated the transfected DNA into nuclear chromosomes. Depending upon the particular construct used for transformation, homologous integration was detected in the P. falciparum dhfr-ts locus (chromosome 4) or in hrp3 and hrp2 sequences that were used in the plasmid constructs as gene control regions (chromosomes 13 and 8, respectively). Transformation by homologous integration sets the stage for targeted gene alterations and knock-outs that will advance understanding of P. falciparum.

publication date

  • February 6, 1996



  • Academic Article


Digital Object Identifier (DOI)

  • 10.1073/pnas.93.3.1130

PubMed ID

  • 8577727

Additional Document Info

start page

  • 1130

end page

  • 4


  • 93


  • 3