From genotype to phenotype: physiological assessment of mitochondrial metabolism in divergent lineages
Currently working in Blier's Lab in the University of Québec in Rimouski, I have broaden my skills to eco-physiology, officially joining the gang of mitochondriacs! Among the environmental parameters that may influence mitonuclear coadaptation in ectotherms is temperature, probably due to the thermo-sensitivity of mitochondrial bioenergetic activities. Complex enzymatic pathways interact synergetically in the mitochondria, and their catalytic capacity are known to be highly sensitive to thermal variations. Mitochondrial function is therefore key to thermal adaptation in populations and influences biogeographic distribution of species. I am working on documenting the mitochondrial phenotypes of divergent lineages of Macoma sp. distributed in contrasted temperature regimes and within hybrids where milo-nuclear incompatibilities might occur.
Mito-nuclear interaction in species with DUI
The ANR project DRIVE (PI E.Pante) focuses on the unique mitochondria inheritance system in Macoma balthica (Fig1), the double uniparental inheritance (DUI). This sytem could cause mito-nuclear genetic incompatibilities (MNI) which have recently gained recognition as an important cause of hybrid breakdown and reproductive isolation. we combine a functional investigation of mitonuclear interactions (OXPHOS genes) to the analyses of hybrid zones among biogeographic regions to test whether DUI can play a significant role in maintaining barriers to gene flow among divergent populations by the way of MNIs
Genomic tools to better estimate skates population size
I used RADseq to document the fine scale distribution of the genetic diversity in the skate Raja clavata. From that, a subset of informative SNPs was selected to carry out large scale parentage assignations (bay of biscay) as an innovative method to evaluate census population size for long-lived, scarce species such as most skates (close-kin mark-recapture abundance estimation).
Metabarcoding applied to the study of seasonal variations of the diversity of the meroplankton
The meroplankton, a group of organism present in the plankton only for a limited period, is mainly composed of larvae of marine invertebrates. Because of its small size and and the lock of morphological diagnostic traits, I developed NGS metabarcoding methods to study the diversity in the meroplankton and its temporal variations. We were also able to accurately trace the occurence of larvae from non-indigenous species.
Invasion genomics in a poorly diverse macro algae
Sargassum muticum is a selfing brown algae native from Est Asia that has invaded most of the temperate rocky shore across the globe. Its genetic diversity was so low that microsatellite makers were useless to investigate its invasion history and it took genome-wide screening of polymorphism through RADsequencing to be able to be resolutive enough. We showed that this species has invaded Europe as a secondary invasion process from the East pacific coast where it had been introduced along with shellfish culture...and all that with barely detectable genetic diversity.
Conservation genetics of the Atlantic salmon
A combined approach of population and quantitative genetics was used to investigate the genetic and phenotypic impact of past and present management measures of wild populations of salmo salar such as stocking from distant rivers and supplementation through pisciculture. I compared neutral and adaptive genetic diversity in one river between 1970 and 2005 and showed that despite a drastic decline of the population, genetic diversity at a gene involved in immune response increased. Also I documented the evolution of genetic introgression in a stocked population with non-native fish and showed the long-term genetic and phenotypic effect of such operations. We also investigated the adaptive divergence in thermal plasticity in embryonic life stages of Atlantic salmon suggesting that salmon populations may differentially respond to temperature variations induced by climate change. Also differential response of divergent populations to hypoxic stress could lead to outbreeding depression under stressful environmental conditions.
Evolution of the reproductive systems
I was first interested in the study of reproductive systems and their effects on the evolution of populations and species in Masters when I studied the self-incompatible Arabidopsis thaliana. I compared the distribution of the genetic diversity at neutral marker and the S-locus. During my PhD, I studied a highly successful invasive gastropod Crepidula fornicata and focused on how its reproductive system (protandry: sex-change from male to female) combined to another of its specific trait (gregarity) could play a role in its invading success (reproductive insurance). I documented how individuals reproduced within a gregarious groups (multiple parternity) and its effect on larval growth rate, and how population dynamics through larval recruitment could trigger sex-change at the scale of a population to maintain a balanced sex-ratio.