Figure 3

Aversion to PTC in taster mice develops over several days. Preference ratios (mean ± SE) for BALB/cBy (BALB), C3HeB/Fe (C3), and BALB × C3 F₁ (n = 10/strain) to 0.03 mM PTC over six consecutive 48-h tests. The dotted line represents a preference score of 0.5, which indicates equivalent consumption from solution and water tubes. Preference ratios for BALB and F₁ mice decreased following the initial test period; by the final test period these mice were strongly avoiding PTC. C3 mice remained indifferent to the taste of PTC across the entire test period. Strain differences in "developed aversion" to PTC have a genetic basis, with complete dominance of the avoider phenotype. However, the avoidance phenotype does not necessarily reflect increased bitter taste sensitivity. Figure from Boughter (unpublished).