Figure 3.

Thermal death time curves and test of injury additivity between two temperatures. (A) Flies were exposed to a static stressful temperature until coma onset (t_coma). Each point is the median t_coma of a group (n = 2–10) and TDT curves are made for each sex by linear regressions of median log₁₀(t_coma) vs. assay temperature. (B) Groups of flies (n = 5–6 per sex) were exposed to a high temperature (~ 39.5 °C) and then, after different durations, transferred to a lower temperature (~ 36.5 °C) where median t_coma was recorded. The exposures are shown as fractions of injury resulting in coma at T₁ (x-axis) and T₂ (y-axis), where small and large fractions indicate brief and long exposures, respectively (i.e. brief exposure results in small accumulation of injury relative to the critical amount of injury). If injury acquired at two different temperatures is additive, the two fractions should sum to 1, i.e. follow the (full) line of additivity. (C) A similar experiment as (B), but with initial exposure to ~ 36.5 °C and the subsequent exposure to ~ 39.5 °C.