Genetic background determines resistance and tolerance of polyQ aggregation. (a,b) Relative ranking of indicated polyQ-carrying strains in aggregation and two toxicity correlates: (a) abnormally short lifespan and (b) muscle dysfunction. Aggregation ranking is as described in supplementary materials (see Additional file 2: Figure S2b). Strains that are paired share aggregation rank, and RIL 16 is unpaired. Placement above or below the diagonal indicates decreased or increased tolerance, respectively. (c) Variation in polyQ aggregation tolerance measured by shortening of lifespan could be separated from that measured by muscle dysfunction. DR1350 is indicated as an example of decreased tolerance in terms of muscle dysfunction relative to lifespan.