Is the reproductive success and lifespan of wild animals rooted in their mitochondrial function?

Supervisors: Dr Pierre Bize, Dr Julien Martin

Project Description:

Mitochondria are organelles present in almost all animal cells that have as main responsibility to convert food into cellular energy usable for growth, reproduction and maintenance. Remarkably, just like industrial plants, mitochondria also generate ‘waste’ through the production of reactive oxygen species (ROS). Oxidative stress occurs when ROS production exceeds the antioxidant defences, generating oxidative damage to biomolecules that can ultimately alter organismal reproduction and survival.

Nowadays there is fast growing evidence from medical research on the influence of mitochondria on energy balance and oxidative stress and, ultimately, on reproduction and survival of cell cultures, laboratory animal and humans. By contrast, there is almost no information on how important mitochondria are in shaping the reproduction and survival of wild animals. The main reason of such knowledge gap is that classical approaches to study mitochondrial function rely on liver and muscle samples, which are too invasive to be collected from most wild animals.

To overcome this issue, in this PhD project you will use an innovative approach developed by the PI and partners that consists in studying mitochondrial functioning in bird red blood cells. We have recently demonstrated that birds possess functional mitochondria within their red blood cells and that a minimally invasive blood sample can be used to obtain meaningful information (reflecting other tissues) on mitochondria [1]. You will apply this innovative approach to measure mitochondrial traits (respiration, ROS production and density) in red blood cells from an extremely well characterised wild population of Alpine swifts [2,3] and use state-of-the-art statistics with the aim to shed new light on selection and evolutionary potential of mitochondrial traits in natural populations. You will investigate natural selection on mitochondrial traits by testing which mitochondrial traits promote higher reproductive success and/or survival, and you will address the evolvability of mitochondrial traits by using a quantitative genetic approach on long-term data from a wild population of alpine swift, in Switzerland. The existence of a detailed pedigree built over more than 20 years for a large number of related individuals allows to make useful statistical inference about the influence of genetics and environment on mitochondrial traits. Hence, this PhD project will allow you to generate new knowledge on the importance of mitochondrial traits in influencing wild animal life histories by using a cross-disciplinary approach borrowing laboratory tools from cell biology and animal physiology and statistical tools from evolutionary biology and quantitative genetics.

The PhD project will offer a unique opportunity for the student to learn a variety of important methods in animal physiology and evolutionary biology and to participate in the field work. We will provide a thorough training in laboratory skills, experimental design, basic and advanced statistical analyses, animal eco-physiology and evolutionary biology. The project will be based at the University of Aberdeen where the student will benefit from interaction with a thriving community of postgraduate students, postdocs, and faculty in animal physiology and evolutionary biology.

References:

Bize, P., Criscuolo, F., Metcalfe, N.B., Nasir, L. & Monaghan, P. 2009. Telomere dynamics rather than age predict life expectancy in the wild. Proceedings of The Royal Society B-Biological Sciences 276: 1679-1683.
Bize, P., Daniel, G., Viblanc, V.A., Martin, J.G.A. & Doligez, B. 2017. Negative phenotypic and genetic correlation between natal dispersal propensity and nest-defence behaviour in a wild bird. Biology Letters 13: 20170236.
Stier, A., Romestaing, C., Schull, Q., Lefol, E., Robin, J.-P., Roussel, D. & Bize, P. 2017. How to measure mitochondrial function in birds using red blood cells: a case study in the king penguin and perspectives in ecology and evolution. Methods in Ecology and Evolution 8: 1172–1182.

If you want to apply for this project, please go to this link.

 

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