Several alleles of the multidrug-resistance gene are closely linked to chloroquine resistance in Plasmodium falciparum

Abstract

THE lethal form of human malaria caused by Plasmodium falciparum is virtually uncontrollable in many areas because of the development of drug resistance, in particular chloroquine resistance (CQR). CQR is biologically similar to the multiple drug resistance phenotype (MDR) of mammalian tumour cells, as both involve expulsion of drug from the cell and both can be reversed by calcium channel antagonists1. A homologue (pfmdr1) of the mammalian multidrug resistance gene has been implicated in CQR because it is amplified in some CQR isolates of P. falciparum2,3 as is an mdr gene in MDR tumour cells4. We show here that the complete sequences of pfmdr1 genes from 2 CQ sensitive (CQS) P. falciparum ..