Fig. 2. Glucose-derived ¹³C incorporation into essential amino acid precursor metabolites.

a Schematic representation of central carbon metabolism. Essential amino acids are shown in black boxes and essential amino acid precursors monitored in this study are shown in gray boxes. Kinetic incorporation of glucose-derived ¹³C into b–f glycolytic, g pentose-phosphate, h–j TCA cycle metabolites. Kinetic incorporation of glucose-derived ¹³C into nonessential amino acid precursors, glutamate (k) and aspartate (l). Box-plots show the percentage of the spittlebug intracellular metabolite pool that has accumulated ¹³C-labeled fraction.