Mitochondrial uncoupling as a regulator of life-history trajectories in birds: an experimental study in the zebra finch.

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State: Serval
Version: Final published version
Serval ID
serval:BIB_83041A451A4A
Type
Article: article from journal or magazin.
Collection
Publications
Title
Mitochondrial uncoupling as a regulator of life-history trajectories in birds: an experimental study in the zebra finch.
Journal
Journal of Experimental Biology
Author(s)
Stier A., Bize P., Roussel D., Schull Q., Massemin S., Criscuolo F.
ISSN
1477-9145 (Electronic)
ISSN-L
0022-0949
Publication state
Published
Issued date
2014
Volume
217
Number
Pt 19
Pages
3579-3589
Language
english
Abstract
Mitochondria have a fundamental role in the transduction of energy from food into ATP. The coupling between food oxidation and ATP production is never perfect, but may nevertheless be of evolutionary significance. The 'uncoupling to survive' hypothesis suggests that 'mild' mitochondrial uncoupling evolved as a protective mechanism against the excessive production of damaging reactive oxygen species (ROS). Because resource allocation and ROS production are thought to shape animal life histories, alternative life-history trajectories might be driven by individual variation in the degree of mitochondrial uncoupling. We tested this hypothesis in a small bird species, the zebra finch (Taeniopygia guttata), by treating adults with the artificial mitochondrial uncoupler 2,4-dinitrophenol (DNP) over a 32-month period. In agreement with our expectations, the uncoupling treatment increased metabolic rate. However, we found no evidence that treated birds enjoyed lower oxidative stress levels or greater survival rates, in contrast to previous results in other taxa. In vitro experiments revealed lower sensitivity of ROS production to DNP in mitochondria isolated from skeletal muscles of zebra finch than mouse. In addition, we found significant reductions in the number of eggs laid and in the inflammatory immune response in treated birds. Altogether, our data suggest that the 'uncoupling to survive' hypothesis may not be applicable for zebra finches, presumably because of lower effects of mitochondrial uncoupling on mitochondrial ROS production in birds than in mammals. Nevertheless, mitochondrial uncoupling appeared to be a potential life-history regulator of traits such as fecundity and immunity at adulthood, even with food supplied ad libitum.
Keywords
Mitochondria, Uncoupling, Free radical theory of ageing, Oxidative stress, Reactive oxygen species, Life-history trade-off, Bird
Pubmed
Web of science
Open Access
Yes
Create date
30/10/2014 11:17
Last modification date
08/05/2019 21:15
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