Comparison of sensitivity profiles from environmental to genetic perturbations. High dimensional sensitivity information for mutants in threonine biosynthetic pathway (circled in red) were obtained from SGA experiments . These profiles correlate with the sensitivity profile obtained in this study when strains are grown on galactose:urea. This suggests a correspondence between the internal states of the cells when grown in a specific environment, and when subjected to a specific genetic perturbation. For example, hom2Δ, hom3Δ, hom6Δ, and thr4Δ mutants would all be expected to accumulate aspartate because these mutants shut down a major metabolic shunt for aspartate. The phenotypic similarity in genetic interaction space between these mutants and growth on galactose:urea suggests that growth on galactose:urea may cause the internal accumulation of aspartate or some other metabolic intermediate unique to the hom2Δ, hom3Δ, hom6Δ, and thr4Δ mutants.