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Difference between revisions of "Pichaud 2011 Am J Physiol Regul Integr Comp Physiol"

From Bioblast
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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 ([[ET-pathway]]) differed between the mitotypes at 24 °C. Catalytic capacities were higher in flies harboring siII than in those harboring siIII mitochondrial DNA (2,129 vs. 1,390 pmol O2·s<sup>-1</sup>·mg protein<sup>-1</sup>).
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 ([[Electron transfer pathway]]) differed between the mitotypes at 24 °C. Catalytic capacities were higher in flies harboring siII than in those harboring siIII mitochondrial DNA (2,129 vs. 1,390 pmol O2·s<sup>-1</sup>·mg 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 O2·s<sup>-1</sup>·mg 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 O2·s<sup>-1</sup>·mg 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
Line 12: Line 12:
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 ET-pathway, both mitotypes revealed
capacity of the different enzymes of the ET pathway, 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 ET-pathway is a robust system in terms of functional
sensitive and that the ET pathway 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 09:35, 3 June 2020

Publications in the MiPMap
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.

» PMID: 21451139 Open Access

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 (Electron transfer pathway) differed between the mitotypes at 24 °C. Catalytic capacities were higher in flies harboring siII than in those harboring siIII mitochondrial DNA (2,129 vs. 1,390 pmol O2·s-1·mg protein-1). The cytochrome c oxidase activity was also higher in siII than siIII flies (3,712 vs. 2,688 pmol O2·s-1·mg 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 ET pathway, 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 ET pathway is a robust system in terms of functional and regulatory properties across a wide range of temperatures. Keywords: Metabolism; Mitochondrial DNA; Mitochondrial respiration; Temperature; Drosophila simulans

O2k-Network Lab: CA Rimouski Blier PU, AU Sydney Ballard JW


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Organism: Drosophila  Tissue;cell: Skeletal muscle  Preparation: Permeabilized tissue 

Regulation: Temperature 


HRR: Oxygraph-2k