P. chabaudi clones in the AS lineage and their chloroquine responses. A. The AS lineage of drug resistant mutants [35, 55, 56]. Each arrow represents various regimes of selection using drugs (PYR, pyrimethamine; CQ, chloroquine; ATN, artesunate; MF, mefloquine). All strains except AS-15CQ were cloned. B-D. The growth of AS-sens (B), AS-3CQ (C) and AS-30CQ (D) at 0 (red), 3 (yellow) or 10 (blue) mg CQ kg-1 day-1.