Figure 6

Midgut-directed overexpression of MEK alleles with D-site polymorphisms decreased P. berghei oocyst numbers in A. gambiae females in vivo. We allowed 3–5 d old female mosquitoes transformed to overexpress wtMEK, pMEK2 or pMEK5 to feed on P. berghei-infected mice. Twelve days after infection, mosquito midguts were dissected and P. berghei oocysts were counted. The experiment was replicated three times. There were no significant differences in NT mean oocyst counts among replicates (one-way ANOVA), so replicates were combined for analysis. Midgut-specific overexpression of catalytically active MEK (pMEK2) resulted in a significant increase in the number of oocysts per midgut compared to mosquitoes overexpressing wtMEK (P = 0.03). Mutation of the key residues in the D-site (pMEK5), however, resulted in oocyst development that was not significantly different from NT females (P = 0.48) and females transformed with wtMEK (P = 0.11).