Figure 1. Study design.

A. Yeast cells were collected following each of four hydrogen peroxide treatment conditions (pretreated, adapted, acute, and untreated, labeled 1–4). Competitive growth experiments were performed between gene deletion pools grown in adapted versus acute conditions (to identify genes required specifically for adaptation) and between pools grown in acute versus untreated conditions (to identify genes required for the acute response). Gene expression profiling was performed in either adapted or acute conditions versus untreated cells. B. Profiling of wild type growth reveals that pretreatment with mild hydrogen peroxide (green) leads to improved recovery to an OD₆₀₀ threshold (dashed line) compared to no pretreatment (red) following a high dose of hydrogen peroxide. An enlarged version of panel B is available as Figure S1. C. For an individual gene deletion, the acute sensitivity is defined as the difference between the acute and untreated viability. The adapted sensitivity is the fraction of that difference that is recovered by mild pretreatment with hydrogen peroxide.