Figure 1.

A comparison of forward genetic, and forward chemical genetic screening. Forward genetic screens (left) typically involve chemical- or radiation-induced mutagenesis of a wild-type strain, followed by screening mutants for a phenotype of interest, and then identifying the affected gene by complementation. In this example, and as previously described [17], mutants that fail to grow on media containing glucose (green), but not ethanol (blue), identify genes required for glycolysis. In the analogous forward chemical genetic screen (right), chemicals that specifically inhibit growth in glucose, but not ethanol, are predicted to identify chemical inhibitors of enzymes in the glycolysis pathway (represented by the wells circled in red).