Pichaud 2013 J Bioenerg Biomembr
Pichaud N, Ballard JWO, Tanguay RM, Blier PU (2013) Mitochondrial haplotype divergences affect specific temperature sensitivity of mitochondrial respiration. J Bioenerg Biomembr 45:25-35. |
Pichaud N, Ballard JWO, Tanguay RM, Blier PU (2013) J Bioenerg Biomembr
Abstract: The aim of this study was to investigate the effect of temperature changes on the functional properties of mitochondria from two sets of D. simulans fly lines harboring the siII and siIII haplotypes in a common nuclear genetic background. We studied four introgressed isofemale lines possessing the mtDNA of siII and the nuclear background of siIII (siII-introgressed) and four lines possessing siIII mitochondria with its native nuclear genome (siIII-controls). We assessed the catalytic capacities of electron transport system (ET-pathway) at four different temperatures (12, 18, 24 and 28 ΒΊC). The impact of temperature on the pyruvate dehydrogenase (PDH) activity, the mitochondrial respiration (coupled and uncoupled respiration), cytochrome c oxidase activity, as well as the excess capacity of complex IV (COX) were evaluated in these two sets of flies. Our results showed that the temperature coefficient values (Q(10)) measured for mitochondrial respiration in the lower range of temperatures (12 to 18 ΒΊC) showed a 2 to 3 fold increase in siII-introgressed when compared to siIII-controls. This result shows that the impact of temperature on mitochondrial function is different between the two mitotypes studied. The Q(10) results seem to be linked to the apparent COX excess capacity of 193% for siIII-controls that is inexistent for siII-introgressed at 12 ΒΊC. One explanation for these results is that the mitochondria can compensate for the disruption of mito-nuclear interactions at 24 ΒΊC but not at lower temperatures. An alternate explanation would be that siII haplotype confer divergent kinetic properties to the ET-pathway that translate to different temperature sensitivities β’ Keywords: Mitochondrial DNA . Introgression . Electron transport system . Temperature
β’ O2k-Network Lab: CA Rimouski Blier PU, AU Sydney Ballard JW, CA Moncton Pichaud N
Labels: MiParea: Respiration
Organism: Hexapods
Tissue;cell: Skeletal muscle
Preparation: Permeabilized tissue
Regulation: Temperature Coupling state: LEAK, OXPHOS, ET Pathway: N, NS, ROX HRR: Oxygraph-2k