"PfDPY19 gene disruption was not associated with a growth phenotype, not even under endoplasmic reticulum (ER)-stressing conditions that could impair protein folding. The data presented in this work strongly suggests that PfDPY19 is unlikely to play a critical role in the asexual blood stages of the parasite, at least under in vitro conditions. "

\'We further show that genetic disruption of DPY19 in P. falciparum is necessary and sufficient to prevent C-mannosylation in the parasite, impair egress following gametocyte activation and abrogate ookinete infection of the mosquito midgut. Complementation of DPY19 restored the transmission defect and re-instated C-mannosylation activity, definitively validating tryptophan C-mannosylation as essential for P. falciparum infection of the mosquito, which is critical for onward transmission of the parasite.\'