Male fecundity and optimal gametocyte sex ratios for Plasmodium falciparum during incomplete fertilization.
A mathematical model of the within-vector dynamics of Plasmodium falciparum in an Anopheles mosquito with unbiased random mating and incomplete fertilization is used to investigate the effects of varying fecundity and population size on the gametocyte sex ratio when strains maximize their individual fitnesses. Previous studies considered either the effects of variable fecundity or the effects of incomplete fertilization. Here we investigate the simultaneous effects of variable fecundity, incomplete fertilization, and variable number of ingested gametocytes per strain on the optimal gametocyte sex ratio. Our model results agree with others in the case of two identically sized populations in that large differences in fecundities lead to female-biased total population sex ratios. When the assumption of identically sized populations is relaxed in our model, population sex ratios vary from highly female-biased to slightly male-biased, depending on relative strain fecundities and population sizes. Our results provide a plausible explanation for the high variation in gametocyte sex ratios of P. falciparum observed in nature.
Department of Mathematics, Lafayette College, Easton, PA 18042, USA. tebohewm@lafayette.edu
Miranda I
MI
Teboh-Ewungkem
Miao
M
Wang
D000818:Animals; D005260:Female; D005298:Fertility; D005306:Fertilization / Q000502:physiology*; D008297:Male; D010963:Plasmodium falciparum / Q000166:cytology* / Q000502:physiology*; D012744:Sex Ratio