Arginine pathway mutants lack arginine and build up pathway intermediates. (A) Three data traces of arg mutants are displayed, as collected via the high-throughput data pipeline, and compared with the parental strain trace. Numbers above the peaks indicate percentage area. The arg1, arg3, and arg4 mutants show depletion of arginine compared with the levels in the parental strain trace. As expected from the arginine synthetic pathway, the arg1 and arg4 mutants accumulate citrulline and the arg3 mutant accumulates ornithine. All three mutants accumulate lysine. (B) Metabolite conversions in the arginine pathway of yeast. The gene names above the arrows correspond to the enzyme catalyzing the reaction indicated.