Co-supervised by:

Alexander Culley (Regular member)

Research project description

Microbiota of Arctic char (Salvelinus alpinus) in the Arctic: Identification of the biotic and abiotic factors that control the microbial functions beneficial to the energetic performance of Arctic Charr

IntroductionArctic char (Salvelinus alpinus) is a key species in the north because it is widespread in the Canadian Arctic and it is the main source of protein and polyunsaturated fat acids for the Inuit people. Nowadays, this species is facing multiple stressors such as water chemistry modifications, the bioaccumulation of pollutants and the migration of pathogen populations which affect their health and productivity. The microbiota (e.g. microbial community living in the body surface of its host) is known to play an important physiological role and constitutes the first immune barrier to the host. ObjectivesThe main objective of my PhD is to study the diversity of host-microbial interactions in gills (including viruses) in arctic and subarctic populations of Salvelinus alpinus. As the commensal bacteria of the microbiota seem to contribute to the health of the host by providing protection against infection by pathogens, we want to study the consequences of disturbances in natural environments on the complex relationships existing between Arctic char and its gill microbiota. Then, because it also appears that the host has an influence on the structure of its microbiota, we want to determine if the genotype of Salvelinus alpinus influences the recruitment of microbial communities. Study sitesThanks to the collaboration with the teams of Milla Rautio (Université de Chicoutimi), Jean-Sébastien Moore (Université Laval) and Julien Mainguy (Ministère des forêts, de la faune et des parcs) I was able to get samples from Cambridge Bay in Nunavut, Hudson Bay, Ungava Bay and Deception Bay in Nunavik. Material and methodsThe gills were collected in the field with NAP buffer. The analysis of the bacterial communities was done by sequencing the transcrits 16s RNA genes by Miseq Illumina. We will perform a metatranscriptomic RNA-seq analysis to look at all the genes and functions expressed by the different microorganisms (including viruses) and to compare the expression profiles between the different lakes. The adipose fins of the fish were used for DNA extraction and were sequenced by GBS with IonTorrent at the IBIS sequencing platform. A Genome Wide Association Studies (GWAS) study will be done to see if the Canadian Arctic genotype of Salvelinus alpinus influences the recruitment of microbial communities. Expected resultsWe expect to observe a divergence in gene expression in the different populations of Arctic char sampled according to gradients in temperature, mercury concentration and latitudes. We also expect that SNP markers in the Arctic char genome will be correlated with variability in the composition and functionality of the microbiota.

Research Site Coordinates