Changes in the respiratory chain complexes activities and in the mitochondrial DNA content during ageing in D. subobscura.
The time course (age 0-8 weeks) of the enzyme activities of respiratory chain complexes I, III and IV and of citrate synthase, and the cell mitochondrial/nuclear DNA content ratio were studied in Drosophila subobscura. The activities of the three respiratory complexes decreased with age, but with different kinetics. The activities of complexes I and III remained nearly stable between weeks 0 and 3 (falling by 6% and 15%, respectively), and then gradually decreased; after 8 weeks residual activities were about 50% of the initial value for complexes I and III. The activity of complex IV fell in the first week, decreasing continually to week 8, where residual activity was 30% of the initial value. No significant age-related change in citrate synthase activity was observed. Mitochondrial DNA (measured by mitDNA/nucDNA) increased linearly up to week 5 (2.6-fold) and then dropped by 40% in week 6 though it remained higher than initial values.
Morel
F
F
Equipe Génome mitochondrial, Université Blaise Pascal-Clermont II, Aubière, France.
Mazet
F
F
Touraille
S
S
Alziari
S
S
D000375:Aging / Q000378:metabolism*; D000818:Animals; D002950:Citrate (si)-Synthase / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000378:metabolism*; D004330:Drosophila / Q000378:metabolism*; D004579:Electron Transport / Q000502:physiology*; D042967:Electron Transport Complex I; D014450:Electron Transport Complex III / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism; D005069:Evaluation Studies as Topic; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism
D004272:DNA, Mitochondrial; D009247:NADH, NADPH Oxidoreductases; D003576:Electron Transport Complex IV; D002950:Citrate (si)-Synthase; D042967:Electron Transport Complex I; D014450:Electron Transport Complex III