20 MAI 2016 - 13H

Séminaire externe IBPS - Evaluating genetic adaptation and epigenetic response to pathogen pressures

Lluis Quintana Murci, Institut Pasteur, Paris.

Lieu : Amphithéâtre Charpak, LPNHE | Campus Jussieu

Résumé :
Infectious diseases have been a major cause of human mortality, so natural selection is expected to act strongly on host defence genes. This is particularly expected for innate immunity genes, as they represent the first line of host defence against pathogens. I will present different cases of how some of these genes and the pathways they trigger have been targeted by natural selection, helping to delineate genes that fulfil essential functions in host defence, with respect to those exhibiting higher immunological redundancy. 

I will also discuss how population-specific genetic variation can profoundly impact immune-related molecular phenotypes, such mRNA and miRNA expression upon infection (expression quantitative trait loci – eQTL - mapping), and how these studies increase our understanding of immunological mechanisms under genetic control that have been crucial for our past and present survival against infection. 

Finally, I will discuss how the differences in lifestyle and habitat of human populations affect the epigenetic landscape of the human genome. Specifically, our studies show that methylation variation associated with recent changes in habitat mostly involves immune functions, whereas that associated with historical lifestyle primarily affects developmental processes. Our work increases our understanding of whether and how populations are able to respond/adapt to environmental changes, including those related to pathogen pressures, over different time scales.