Research Paper Advance Articles

Figure 1. Protein restriction increases mitochondrial mass, mitochondrial DNA copy number and promotes mitochondrial respiration in aging fly brains. (A, B) Gene ontology analysis of iTRAQ global proteomics. Upregulated (red) and downregulated (blue) protein semantic groups in 15-day-old 12% yeast- and 2% yeast fed fly brains. Numbers indicate the numbers of proteins found in the individual semantic groups. (C) PPI network clustering analysis for the selected semantic groups of interest. Diagrams were created using DAVID software (version Dec. 2021). False discovery rate FDR p-values were reported here. (D) qPCR of mitochondrial DNA copy number relative to nuclear DNA in 15-day-old 12% yeast or 2% yeast fed fly brains (n= 9 biological samples. Each biological sample contains at least 3 fly brains). (E) Basal respiration of 15-day-old 12% yeast or 2% yeast fed fly brains. (F) Maximal respiratory of 15-day-old 12% yeast or 2% yeast fed fly brains. (G) Basal respiration of 15-day-old 12% yeast or 12% yeast + Spd fed fly brains. (H) Maximal respiration of 15-day-old 12% yeast or 12% yeast + Spd fed fly brains. (I) Basal respiration of 15-day-old 2% yeast or 2% yeast + Spd fed fly brains. (J) Maximal respiration of 15-day-old 2% yeast or 2% yeast + Spd fed fly brains. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. ns, not significant. Data are mean ± SEM. P-values were determined by two-tailed paired t-test (D), or by two-tailed Mann-Whitney U test (E–H), or two-tailed unpaired t-test (I, J).