| Project Detail |
In Eukaryotes mitochondria are fuelling almost all biological processes, and therefore mitochondrial traits are expected to be under strong selection and to play a major role in shaping adaptation to the environment and the diversity of animal life histories. Yet, how variable are mitochondrial traits across individuals, whether this variation is influenced by genetics and environment, including disruption of mitochondrial traits by pollutants, and what consequence has this variation on growth, reproduction and survival, and through which pathways, remain virtually unexplored questions in wild vertebrates. To gain new knowledge on these fundamental questions we will apply minimally invasive protocols recently developed by the PI to measure mitochondrial traits in avian red blood cells in two different natural bird populations that are well suited to achieve the general objectives and specific questions of the proposed project. Research is organised in two PhDs with complementary knowledge gains.PhD A | Selection and evolvability of mitochondrial traits in a natural population of Alpine swifts(A.1) What is the genetic architecture of mitochondrial traits in this natural bird population? Using quantitative genetic models (animal models), we will investigate for the first time the heritability and genetic correlations between mitochondrial traits in outbred individuals under realistic environmental conditions.(A.2) What is the strength and direction of selection on mitochondrial traits, and does this change over the life course from nestling to adult? Using fitness regression models, this will be the first study measuring the strength and shape of selection on mitochondrial traits in natural populations from nestlings to adults.(A.3) What are the causal cascading effects of changes in mitochondrial function on reproduction or survival? Using structural equation models, this study will provide unprecedented amount of information on the pathways linking changes in mitochondrial traits to changes in growth, reproduction and survival in the wild.PhD B | Effects of chemical pollutants on mitochondrial traits, individual fitness, and traits’ heritability in wild birds: development of generic tools and implementation of a case study of mercury effects in a natural population of European dippers(B.1) What are the known effects of pollutants on mitochondrial traits and health in birds? Using a systematic review of the literature in birds and meta-analysis for traits with enough data, we will generate detailed information on how pollutants affect the health of birds and highlight the main pathways identified so far.(B.2) Can high-throughput in-vitro assays of mitochondrial traits in bird red blood cells provide a new platform to screen for the toxicity of new chemicals in birds? By carrying out dose-depend experiments using blood cells as a matrix, we will test for toxic effects on mitochondrial traits of mercury and other chemical pollutants identified in B1. This original in vitro approach may help improve chemical safety guidelines for wild birds.(B.3) Bridging the gap between in vitro and in vivo findings: using mercury in the dipper as working example. Using both long-term data (> 6 years) and a cross-fostering experiment between territories with low and high exposure to mercury, we will generate unprecedented amount of information on the effects of mercury from the mitochondrion level to the whole organism in natural bird populations, and by comparing findings between B2 and B3 we aim to bridge the gap between in vitro and in vivo approaches.(B.4) Effects of exposure to mercury on traits’ heritability. Using the long-term monitoring and the cross-fostering experiment, we will test whether traits’s heritability (nestling mitochondrial traits and biometry) is reduced in territories with high exposure to mercury, and thus whether chemical pollution may reduce the potential for evolutionary adaption in wild birds. |
