Meiotic recombination, cross-reactivity, and persistence in Plasmodium falciparum.
We incorporate a representation of Plasmodium falciparum recombination within a discrete-event model of malaria transmission. We simulate the introduction of a new parasite genotype into a human population in which another genotype has reached equilibrium prevalence and compare the emergence and persistence of the novel recombinant forms under differing cross-reactivity relationships between the genotypes. Cross-reactivity between the parental (initial and introduced) genotypes reduces the frequency of appearance of recombinants within three years of introduction from 100% to 14%, and delays their appearance by more than a year, on average. Cross-reactivity between parental and recombinant genotypes reduces the frequency of appearance to 36% and increases the probability of recombinant extinction following appearance from 0% to 83%. When a recombinant is cross-reactive with its parental types, its probability of extinction is influenced by cross-reactivity between the parental types in the opposite manner; that is, its probability of extinction after appearance decreases. Frequencies of P. falciparum outcrossing are mediated by frequencies of mixed-genotype infections in the host population, which are in turn mediated by the structure of cross-reactivity between parasite genotypes. The three leading hypotheses about how meiosis relates to oocyst production lead to quantitative, but no qualitative, differences in these results.
McKenzie
F E
FE
Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Ferreira
M U
MU
Baird
J K
JK
Snounou
G
G
Bossert
W H
WH
D000483:Alleles; D000818:Animals; D003429:Cross Reactions; D009033:Culicidae / Q000469:parasitology; D019143:Evolution, Molecular; D005260:Female; D005838:Genotype; D006801:Humans; D016778:Malaria, Falciparum / Q000276:immunology* / Q000469:parasitology* / Q000635:transmission; D008540:Meiosis / Q000235:genetics*; D008954:Models, Biological; D010963:Plasmodium falciparum / Q000235:genetics* / Q000276:immunology* / Q000472:pathogenicity / Q000502:physiology; D011995:Recombination, Genetic; D014774:Virulence