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Thermal sensitivity of mitochondrial functions in permeabilized muscle fibers from two populations of Drosophila simulans with divergent mitotypes
Author(s) -
Pichaud Nicolas,
Ballard John William,
Tanguay Robert M,
Blier Pierre Ulrich
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.1048.5
Subject(s) - mitochondrial dna , biology , mitochondrion , electron transport chain , drosophila (subgenus) , biophysics , genetics , microbiology and biotechnology , biochemistry , gene
The aim of this study was to use high‐resolution respirometry with permeabilized fibers of thorax muscles of Drosophila simulans to identify differences in mitochondrial performance and thermal sensitivity associated with populations possessing different mitochondrial haplotypes and geographical distributions. We measured the impact of temperature on mitochondrial respiration in two mitotypes of D. simulans using multiple substrate‐uncoupler‐inhibitor titration experiments to investigate the functional consequences of convergent mitochondrial pathways at the Q‐junction of the electron transport system (ETS) from three different branches at four different temperatures. We also measured the excess capacity of complex IV (COX) at the same temperatures during high convergent pathway flux. Differences between mitotypes were detected at 24°C and these differences were proposed to be driven by efficiency of downstream complexes to deplete electrons. The apparent COX excess capacity detected at 12°C may be related to dehydrogenases process since they drive the electron input into the ETS. However, we cannot confirm that the difference in the capacity to fuel the ETS in electrons comes from the divergences in the mitochondrial DNA (mtDNA), it may be related to nuclear‐encoded and mitochondrial‐encoded protein interactions. Supported by the Natural Sciences and Engineering Research Council (NSERC).