PROOF OF INTRAGENIC RECOMBINATION IN PLASMODIUM-FALCIPARUM

Intragenic recombination in the merozoite surface protein MSP-1 of Pla smodium falciparum has been demonstrated in a cross between two cloned lines (3D7 and HB3) of this species. Following passage of a mixture o f the clones through mosquitoes, uncloned progeny were examined by PCR for molecules containing sequences of both parent MSP-1-alleles. A re combinant molecule possessing both 3D7 and HB3 sequences has been obta ined. Such molecules were not obtained from artificial mixtures of the blood forms of each clone. It is concluded that the novel allele was formed by a recombination event during meiosis of a hybrid 3D7/HB3 zyg ote.