FIG 1.

The increased msp2 allelic diversity in high-infection-prevalence populations may arise from superinfection by strains on the same or distinct genomic backgrounds. The gray box represents either an individual or population infected with a predominant strain, A; arrows represent the introduction of either a closely related strain, A′, or a strain B on a distinct genomic background. The multiple chromosomal msp2 alleles are represented by colored segments; each color represents an allele encoding a structurally and antigenically unique Msp2 variant. Strain A′ shares the same genomic background (indicated by the black segments) as strain A but differs in msp2 alleles generated by locus duplication and mutation (*). In contrast, strain B differs in genomic background, indicated by the hatched segments, as well as containing unique msp2 alleles (x).