transfection;
dihydrofolate reductase thymidylate synthase;
episomes;
drug resistance;
D O I:
10.1073/pnas.93.3.1130
中图分类号:
O [数理科学和化学];
P [天文学、地球科学];
Q [生物科学];
N [自然科学总论];
学科分类号:
07 ;
0710 ;
09 ;
摘要:
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.