Priority Research Paper Volume 12, Issue 11 pp 10041—10058

Lactate dehydrogenase expression modulates longevity and neurodegeneration in Drosophila melanogaster

Figure 4. Flies with neuronal overexpression of Ldh show increased neurodegeneration and accelerated decline in locomotor activity rhythms. (A, B) Representative brain section images of 55-day old control elavts>w (A) and elavts>Ldh flies (B) in 25°C (arrows indicate vacuoles). (C, D) Graphs show the average area (C) and number (D) of vacuoles per brain in the brains of elavts>Ldh flies and age-matched controls. Both area and the number of vacuoles were significantly increased in elavts>Ldh (n=36) flies compared to elavts>w (n=38). ****p<0.0001; unpaired t-test with Welch’s correction. (E, F) There was no significant difference in the average area (E) and number (F) of vacuoles in 55-day old repots>Ldh (n=19) brains compared to age-matched repots>w control (n=18). Error bars indicate SEM. (G) Percent of rhythmic elavts>Ldh flies was markedly reduced with age compared to elavts>w controls. (H) Representative actrograms of individual 50-day old elavts>w (rhythmic) and elavts>Ldh (arrhythmic) flies. Gray areas indicate lights off. (I) Percentage of rhythmic repots>Ldh flies were similar to repots>w controls across lifespan. At least 30 flies were tested for each age group and each genotype. (J) Representative actograms of rhythmic 50-day old repots>w and repots>Ldh flies. (K) Total daily activity of 35-day old elavts>Ldh (n=31) flies averaged over six days in constant darkness was significantly reduced relative to control elavts>w (n=30) flies. (L) Total daily activity of 35 days-old repots>Ldh (n=30) flies was also significantly lower than in controls (n=31). Statistical significance by unpaired t-test with Welch’s correction (****p<0.0001). Error bars indicate SEM.