Intra-host interactions of Bacillus thuringiensis strains and their impact on experimental coevolution with Caenorhabditis elegans

CLUSTER: „Experimental evolution and natural variation of Bacillus-invertebrate interactions“

Dr. Rebecca Schulte

Host-parasite coevolution is expected to have fundamental consequences for the evolution of organisms. While extensively studied in theory, experimental evidence is still scarce. Most studies focus however on the interaction between the two antagonists ignoring that within one host, different parasite genotypes may interact and may thus feed-back on the coevolution between host and parasite. The interaction between parasite genotypes may range from competition between genotypes for limited host resources to cooperation for more efficient host exploitation. The aim of this project is to characterise the spectrum of interactions between parasites and to test for the effect the coevolution with a host has on the interaction between parasites. During the last funding period we characterised combinations of different Bacillus thuringiensis strains infecting the nematode Caenorhabditis elegans and ran an evolution experiment to study parasite interactions over a longer time period and to evaluate the role host evolution has on the interactions and vice versa. While the focus of the first funding period was the phenotypic characterisation, during the proposed period we aim at understanding the genetic basis of the interaction between the three parties, i.e. parasiteparasite- host. We will use a combination of population genomic analysis, functional manipulation of candidate genes and testing their effect in experimental evolution and theoretical modelling. This project is proposed as part of the Bacillus-Invertebrate Cluster within the priority programme on Host –Parasite Coevolution (SPP 1399).