Leucine-rich repeat (LRR) proteins can control a binary switch for establishment of P. falciparum infection.

A. LRR proteins APL1A, LRR7059 and LRIM1 influence permissiveness for initial infection, regardless of subsequent parasite intensity, reflected as increased P. falciparum oocyst infection prevalence after loss of gene function. B. APL1A, LRR7059 and LRR7037 do not influence oocyst infection intensity (for clarity only APL1A is shown, data for all genes available in S2 Table). However, LRIM1 function also limits the efficiency of parasite development in established infections, reflected as increased intensity of P. falciparum oocysts after LRIM1 silencing. Graph labels and statistical tests for this and subsequent figures: tests of infection prevalence indicate mean infection prevalence within histogram bars, error bars indicate standard error. For tests of infection intensity, the y-axis is logarithmic to depict both low and high intensity phenotypes, boxplots delineate the first and third quartile, median is indicated within the box, and error bars are 1.5 times the interquartile range. Sample sizes (N) indicate the number of independent replicate experiments, (n) the total number of mosquitoes dissected across replicates. All statistical differences were first tested independently within replicates (individual p-values, S2 Table), and only if individual replicates showed a consistent direction of change, individual p-values were combined using the meta-analytical approach of Fisher. (Significance levels of Fisher-combined p-values: n.s., not significant; * p-value