The effective rate of influenza reassortment is limited during human infection (original) (raw)
Fig 1
Patterns of allele frequency change are altered by the presence or absence of reassortment.
A. Representation of a three-locus system with large population size, and in which rapid reassortment wipes out linkage disequilibrium between alleles at different loci. The ‘A’ variant (red) is under mild negative selection, the ‘G’ variant (green) is under strong positive selection, while the ‘C’ variant is under weak positive selection. B. Given the rapid rate of reassortment, alleles at each locus evolve deterministically over time in accordance with the selection acting upon them. C. Representation of the same system, now with no reassortment. Alleles now evolve according the changes in the frequencies of full sequences in the population; each horizontal row indicates a set of sequences with one of four distinct three-locus genotypes. D. While the initial state of the system, and magnitudes of selection are unchanged, the fates of the red and blue variants are reversed. The AGT genotype is the fittest of the four genotypes; in a process known as genetic hitchhiking, the deleterious red variant is carried by the green to fixation. In a process known as clonal interference, the beneficial blue variant is wiped out in the competition. E. Representation of the same system in which there is finite, but limited reassortment between the variants. F. Given limited reassortment, the association between the red and green variants is gradually eroded so that the red variant is lost over time. After an initial decline, formation of the maximally fit TGC haplotype leads to the blue variant increasing in frequency over time.