Both female and male gametocytes of omg1(-) appeared normal and were able to fertilize. However, ookinete maturation was delayed in omg1(-) compared to PbCas9 parasites. In omg1(-), the ratio of banana-shaped ookinetes to all fertilized cells was less than 10% at 16 hours of culture (hoc), whereas more than half of fertilized cells had become banana-shaped ookinetes in control cultures at the same time point. Nonetheless, disruption of omg1 did not completely impair ookinete development as most fertilized cells became banana-shaped ookinetes prior to 30 hoc.

At 14 days post-infection, the number of oocysts in the midgut of infected mosquitoes was significantly reduced in both clones of omg1(-) compared to controls.