Global change and evolutionary genetics of pathogen resistance in estuarine ecosystems

How global change and increasing physical stress interact with emerging marine diseases is largely unexplored in coastal ecosystems. Evolutionary consequences for such altered interactions between hosts and bacterial pathogens are even less known. Therefore, I will focus on ubiquitous bacterial pathogens (genus Vibrio) that can infect several host species from different key groups (bivalves and fish) within the Wadden sea ecosystem. Established model species, Pacific oysters and marine sticklebacks, will be studied in closer detail because their projected selective responses to rising temperatures point in opposite directions. By exploring the effects and evolutionary trajectories of bacterial pathogens and the genetic architecture of resistance in corresponding hosts, potential consequences of global change and bacterial disease for the ecosystem as a whole can be derived. The goals of the proposed research are to: (i) characterize the symbiont fauna of both host species/groups and identify pathogenic bacteria shared by both hosts, (ii) determine changes in their pathogenicity under global change scenarios, (iii) assess the impact of environmental change on quantitative genetic parameters (G matrices of immune and life history traits) as well as selection on candidate immune genes to quantify genotype x environment (GxE) interactions, and (iv) monitor the evolutionary trajectory of bacterial pathogenicity experimentally evolved on different hosts and different environmental conditions (GxGxE interactions). The fundamental aspect of extending single species GxE interaction to multiple species (GxGxE) explores the evolutionary consequences of parasitism in an ecosystem currently facing global change.

DFG Programme Independent Junior Research Groups