Figure 1. Changes of pyruvate content, TCA activity, and expression patterns of PK, PEPCK, and PGAM during developmental pupal brain. (A) Changes of pyruvate levels in brains of diapause- and nondiapause-destined pupae. (B) Changes of TCA cycle activity in brains of diapause- and nondiapause-destined pupae. (C) Changes in TCA cycle activity by injection of pyruvate. Day-1 diapause-destined pupae were injected with pyruvate and pupal brains were dissected 48 h after injection. Proteins from pupal were extracted and TCA activity was measured and normalized against total protein levels. (D) Termination of pupal diapause in response to pyruvate injection. Day-1 diapause-destined pupae were injected with pyruvate. No treatment, n=58; H2O, n=58; 200 μg, n=54; 400 μg, n=52. Pupae development was determined by examining the location of the pupal stemmata. Developmental expression of PK (E), PEPCK (F), and PGAM (G) by western blotting. Proteins from pupal brains were extracted and detected with corresponding antibodies. The bands were quantified using Image software (ImageJ) and normalized to the levels of H. armigera actin (5 μg). (H) PGAM activity in pupal brains. Enzyme activity was measured and normalized against total protein levels. DP, diapause-destined pupae; NP, nondiapause-destined pupae. Each point represents the means±S.D. of three independent replicates. *, p<0.05; **, p<0.01 (determined by independent t-test).