Salin 2013 Abstract MiP2013
| Salin K, Luquet E, Rey B, Roussel D, Voituron Y (2013) Mitochondrial functioning, a proximate mechanism underlying the pace-of-
life? Mitochondr Physiol Network 18.08.
Life histories describe how organisms grow, mature, reproduce and senesce, and evidence is accumulating that most of the variation in the pace of life of animals can be arranged along a slow-fast continuum. Natural variation in life history traits has largely been studied from an evolutionary viewpoint, highlighting their links to ecological factors and their fitness consequences . It is only recently that researchers have focused their interest on the physiological mechanisms underlying variation in the pace of life . In this context, we proposed that mitochondrial function, the main generator of both energy (adenosine triphosphate, ATP) and reactive oxygen species (ROS), may act as the keystone between the optimization of energy availability for life-history traits and the resulting oxidative cost.
Using both descriptive and experimental approaches, we investigated the relationship between energy flow, oxidative stress and growth in an amphibian anuran model, the common frog Rana temporaria. We hypothesized that mitochondrial uncoupling (resulting in less ATP but also reduced ROS production) induces a slow pace of life (slow growth and slow ageing).
Chronic exposure to an uncoupler (2,4-dinitrophenol) during tadpole development induced a lower growth rate associated with a decreased mitochondrial efficiency of energy transduction and an improved oxidative status (lower ROS production and low oxidative damage despite low antioxidant defenses). In addition, a comparison of physiological parameters of wild frogs exhibiting dissimilar body size showed a higher energy efficiency transduction in frogs exhibiting high growth rate.
Our results suggest that (i) the mitochondrial efficiency of energy transduction could drive the amount of energy available for animal growth, and (ii) studying both facets of mitochondrial function (ATP and ROS production) allows a better understanding of the proximate mechanisms underlying life history trade-offs. Mitochondrial function under the regulation of numerous metabolites and endocrine factors, might represent the physiological link between environmental condition (temperature, resource, stressor events…) and energy allocated to animal performance. This approach is opening new avenues within an evolutionary ecological framework that aims at explaining the diversification of paces-of-life in response to environmental conditions.
• Keywords: Frog
Labels: MiParea: Respiration, Comparative MiP;environmental MiP Pathology: Aging;senescence Stress:Oxidative stress;RONS Organism: Other mammals, Amphibians Tissue;cell: Liver Preparation: Isolated mitochondria, Enzyme, Oxidase;biochemical oxidation
Regulation: ADP, ATP, Coupling efficiency;uncoupling, Inhibitor, Oxygen kinetics, Phosphate, Uncoupler Coupling state: LEAK, OXPHOS, ETS Pathway: S, CIV
1 - Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, UK;
2 - Centre d’Ecologie Fonctionnelle et Evolutive (UMR 5175), Montpellier, France;
3 - Laboratoire de Biométrie et Biologie Evolutive (UMR 5558), France;
4 - Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (UMR 5023), France.
- Stearns S C (1992) The evolution of life histories. Oxford Univ Press.
- Zera AJ, Harshman LG (2001) The physiology of life history trade-offs in animals. Annu Rev Ecol Systematics 32: 95-126.