Pichaud 2011 Am J Physiol Regul Integr Comp Physiol: Difference between revisions
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|journal=Am J Physiol Regul Integr Comp Physiol | |journal=Am J Physiol Regul Integr Comp Physiol | ||
|abstract=In ectotherms, the external temperature is experienced by the mitochondria, and the mitochondrial respiration of different genotypes is likely to change as a result. Using high-resolution respirometry with permeabilized fibers (an in situ | |abstract=In ectotherms, the external temperature is experienced by the mitochondria, and the mitochondrial respiration of different genotypes is likely to change as a result. Using high-resolution respirometry with permeabilized fibers (an in situ | ||
approach), we tried to identify differences in mitochondrial performance and thermal sensitivity of two ''Drosophila simulans'' populations with two different mitochondrial types (siII and siIII) and geographical distributions. Maximal State 3 respiration rates obtained with electrons converging at the [[Q junction]] of the electron transport system ([[ | approach), we tried to identify differences in mitochondrial performance and thermal sensitivity of two ''Drosophila simulans'' populations with two different mitochondrial types (siII and siIII) and geographical distributions. Maximal State 3 respiration rates obtained with electrons converging at the [[Q junction]] of the electron transport system ([[ETS]]) differed between the mitotypes at 24 ยฐC. Catalytic capacities were higher in flies harboring siII than in those harboring siIII mitochondrial DNA (2,129 vs. 1,390 pmol O2ยทs<sup>-1</sup>ยทmg protein<sup>-1</sup>). | ||
The cytochrome ''c'' oxidase activity was also higher in siII than siIII | The cytochrome ''c'' oxidase activity was also higher in siII than siIII | ||
flies (3,712 vs. 2,688 pmol O2ยทs<sup>-1</sup>ยทmg protein<sup>-1</sup>). The higher catalytic capacity detected in the siII mitotype could provide an advantage in terms of intensity of aerobic activity, endurance, or both, if the | flies (3,712 vs. 2,688 pmol O2ยทs<sup>-1</sup>ยทmg protein<sup>-1</sup>). The higher catalytic capacity detected in the siII mitotype could provide an advantage in terms of intensity of aerobic activity, endurance, or both, if the | ||
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dictated by the aerobic capacity of the tissue. Moreover, thermal | dictated by the aerobic capacity of the tissue. Moreover, thermal | ||
sensitivity results showed that even if temperature affects the catalytic | sensitivity results showed that even if temperature affects the catalytic | ||
capacity of the different enzymes of the | capacity of the different enzymes of the ETS, both mitotypes revealed | ||
high tolerance to temperature variation. Previous ''in vitro'' study failed | high tolerance to temperature variation. Previous ''in vitro'' study failed | ||
to detect any consistent functional mitochondrial differences between | to detect any consistent functional mitochondrial differences between | ||
the same mitotypes. We conclude that the in situ approach is more | the same mitotypes. We conclude that the in situ approach is more | ||
sensitive and that the | sensitive and that the ETS is a robust system in terms of functional | ||
and regulatory properties across a wide range of temperatures. | and regulatory properties across a wide range of temperatures. | ||
|keywords=Metabolism; Mitochondrial DNA; Mitochondrial respiration; Temperature; ''Drosophila simulans'' | |keywords=Metabolism; Mitochondrial DNA; Mitochondrial respiration; Temperature; ''Drosophila simulans'' |
Revision as of 11:12, 8 June 2020
Pichaud N, Ballard JW, Tanguay RM, Blier PU (2011) Thermal sensitivity of mitochondrial functions in permeabilized muscle fibers from two populations of Drosophila simulans with divergent mitotypes. Am J Physiol Regul Integr Comp Physiol 301:R48-59. |
Pichaud N, Ballard JWO, Tanguay RM, Blier PU (2011) Am J Physiol Regul Integr Comp Physiol
Abstract: In ectotherms, the external temperature is experienced by the mitochondria, and the mitochondrial respiration of different genotypes is likely to change as a result. Using high-resolution respirometry with permeabilized fibers (an in situ approach), we tried to identify differences in mitochondrial performance and thermal sensitivity of two Drosophila simulans populations with two different mitochondrial types (siII and siIII) and geographical distributions. Maximal State 3 respiration rates obtained with electrons converging at the Q junction of the electron transport system (ETS) differed between the mitotypes at 24 ยฐC. Catalytic capacities were higher in flies harboring siII than in those harboring siIII mitochondrial DNA (2,129 vs. 1,390 pmol O2ยทs-1ยทmg protein-1). The cytochrome c oxidase activity was also higher in siII than siIII flies (3,712 vs. 2,688 pmol O2ยทs-1ยทmg protein-1). The higher catalytic capacity detected in the siII mitotype could provide an advantage in terms of intensity of aerobic activity, endurance, or both, if the intensity of exercise that can be aerobically performed is partly dictated by the aerobic capacity of the tissue. Moreover, thermal sensitivity results showed that even if temperature affects the catalytic capacity of the different enzymes of the ETS, both mitotypes revealed high tolerance to temperature variation. Previous in vitro study failed to detect any consistent functional mitochondrial differences between the same mitotypes. We conclude that the in situ approach is more sensitive and that the ETS is a robust system in terms of functional and regulatory properties across a wide range of temperatures. โข Keywords: Metabolism; Mitochondrial DNA; Mitochondrial respiration; Temperature; Drosophila simulans
โข O2k-Network Lab: CA Rimouski Blier PU, AU Sydney Ballard JW
Labels:
Organism: Drosophila
Tissue;cell: Skeletal muscle
Preparation: Permeabilized tissue
Regulation: Temperature
HRR: Oxygraph-2k