Infectivity to mosquitoes of Plasmodium falciparum clones grown in vitro from the same isolate.

In an attempt to produce a line of cultured Plasmodium falciparum parasites consistently infective to mosquites, a Brazilian isolate, IMTM 22, was cloned by the limiting dilution method. Five of the resulting clones were examined in detail. The clones were found to differ in their ability to produce micro- and macrogametocytes, to exflagellate and to infect Anopheles freeborni mosquitoes. The stability of one clone in producing microgametocytes and in its ability to produce oocysts and sporozoites in mosquitoes has been documented through 15 subcultures. This clone should provide a reliable source of infectious gametocytes for genetic studies and vaccine development.