S-antigens and isozymes in strains of Plasmodium falciparum.

Evidence was found for the independent reassortment of parasite genes for S-antigens and isozymes. The Lagos and Palo Alto strains of Plasmodium falciparum had the same isozyme forms of PGD and LDH but different S-antigens. In contrast, the BW (Gambia) and Palo Alto strains had different isozyme forms of GDH but shared some S-antigens. From artificial mixtures of parasites with different isozymes of GDH and different S-antigens, clones were derived in vitro which had a single isozyme type of GDH and a single type of S-antigen.