Modeling spatial evolution of multi-drug resistance under drug environmental gradients
Fig 4
The basis for the atlas of multi-drug resistance evolution patterns over space.
A. The four canonical mutant types for resistance phenotypes to two drugs, distributed in the (α, β) space of rescaling parameters: blue—fully resistant to drug 1 and sensitive to drug 2; red—fully resistant to drug 2 and sensitive to drug 1; purple—intermediate resistance to both drugs; brown—wild-type, sensitive to both drugs. The 3 drug fitness landscapes used are: B. synergistic, C. independent and D. antagonistic, as specified in Eq 16 for q = 1. These drug landscapes will be used to give rise to gi(z) = G(αix(z), βiy(z)) as a function of two drug variation over space x(z) and y(z). The relative fitnesses of the strains are hence dependent both on drug variation over space and on the details of the underlying growth landscape G.