The genetics of drug resistance in malaria parasites.

The available experimental data on the genetics of drug resistance in malaria parasites are reviewed. Seven possible mechanisms for the origin of drug resistance are considered, and it is pointed out that spontaneous gene mutation is probably the most important. Experiments on the production of pyrimethamine-resistant and chloroquine-resistant strains of rodent Plasmodium species, and on the inheritance of such drug resistance, are reviewed. Relevant biochemical data are also considered in relation to the genetics of drug resistance. Studies on competition between drug-sensitive and drug-resistant parasites in mixed populations of rodent plasmodia are described. The implications of these findings for drug resistance in P. falciparum are discussed.