A central role for P48/45 in malaria parasite male gamete fertility

Fertilization and zygote development are obligate features of the malaria p arasite life cycle and occur during parasite transmission to mosquitoes. Th e surface protein PFS48/45 is expressed by male and female gametes of Plasm odium falciparum and PFS48/45 antibodies prevent zygote development and tra nsmission. Here, gene disruption was used to show that Pfs48/45 and the ort holog Pbs48/45 from a rodent malaria parasite P. berghei play a conserved a nd important role in fertilization. p48/45(-) parasites had a reduced capac ity to produce oocysts in mosquitoes due to greatly reduced zygote formatio n. Unexpectedly, only male gamete fertility of p48/45(-) parasites was affe cted, failing to penetrate otherwise fertile female gametes. P48/45 is show n to be a surface protein of malaria parasites with a demonstrable role in fertilization.