Figure 2.Flies overexpressing Ldh have increased mRNA levels, LDH activity, elevated lactate, and shortened lifespan. (A) Ldh mRNA levels were significantly increased in the heads of young and old tim>Ldh compared to age-matched tim>w control flies. Values are reported as a percentage of expression relative to age-matched tim>w set to 100% (n=4). (B) LDH enzyme activity was significantly increased for the pyruvate to lactate reaction in the heads of 55-day old tim>Ldh flies compared to tim>w controls (n=4). (C) Lactate concentrations were significantly higher in the heads of tim>Ldh flies compared to age-matched tim>w controls (n=4). Error bars in A-C indicate SEM. Statistical significance was determined by Unpaired t-test with Welch’s correction (***p<0.001; **p<0.01; *p<0.05). (D) Survival curves of tim>Ldh (n=193) and tim>w (n=170) males. Median lifespan was significantly reduced in tim>Ldh flies compared to control (Gehan-Breslow-Wilcoxon test; p<0.0001).
