Project Summary/Abstract Plasmodium falciparum is the major global cause of malaria morbidity and mortality and is especially devastating in pregnant women and children in sub–Saharan Africa. Anopheline mosquitoes are essential for the spread of new infections, requiring ingestion of mature sexual stages from an infected person and then a second blood meal once infectious sporozoites are in the mosquito salivary glands. Development of sexual stages in an infected person’s blood cells requires a complex ~14-day development phase. Even with a lot of recent progress, many processes essential for sexual stage development remain poorly understood. Our group has developed a functional genomics approach using random piggyBac mutagenesis, which can be applied at genome scale to identify the P. falciparum genes essential for gametocyte development. We used this approach to complete the first saturation mutagenesis screen of P. falciparum to functionally annotate genes essential and dispensable for asexual blood-stage development. We estimate many genes in the cryopreserved saturation mutagenesis library are likely to be sexual-stage genes and this mutant library can be used for a forward phenotypic screen to identify most genes needed for sexual stage development. Advanced ‘omics analyses of selected mutants will be used to validate phenotypes and elucidate the broader cellular events that underlie the phenotypes during sexual stage development in infected human blood cells. The project combines expertise in gametocyte biology, advanced computational genomics, and phenotype comparisons with clinical isolates.