SPP 1819:  Rapid evolutionary adaptation: Potential and constraints

• Subject Area: Biology ; Medicine
• Term: from 2015 to 2023
• Website: Homepage
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 255619725

Several scenarios of rapid evolution are described, but one of the most prominent is the adaptation of species in parasitic or pathogenic interactions. Many biotrophic pathogens are highly host specific, which is often discussed with respect to trench warfare or arms race dynamics in the interacting populations. Several virulence factors have been identified in the last years in various plant-pathogen systems, but the genetic mechanism of host specificity and its evolution remains unclear up to date. Traditionally, gene-for-gene models have been served to explain host specificity and coevolution, but only few model systems seem to rely on such a reciprocal interaction of avirulence and resistance genes. Thus, the mechanisms of host specificity and rapid adaption to new hosts as needed for host jumps are unknown in most model systems. In recent years the relevance of hybridization to overcome an evolutionary dead-end situation of host specificity became popular and several populations studies focused on introgressive hybridization to explain host jumps or host switches. However, these studies used an approach based on population genetics and did not analyse the mechanisms of hybridization so far.Here we propose to use experimental evolution in the model system Microbotryum–Silene to produce hybrids of related species and select for strains after host jumps on new hosts. Preliminary studies showed, that hybrid infections occur at reasonable frequencies and even backcrosses with the parental strains result in positive infections and gained pathogenicity with respect to new hosts. Comparative genomics of the offspring reveals frequent recombination events on most chromosomes. We propose to extend the experimental evolution using hybrids into F3 backcrosses and to sequence a relevant number of representative strains of each generation to compare the genome content and organisation in parents, hybrids and backcrosses. This will allow identifying candidate loci relevant for host specificity. In addition, we plan to analyse the transcriptome of compatible and incompatible host-pathogen interactions, to validate the candidate genes and to analyse their role during host specific infection. The transcriptome approach would also allow differentiating between dosage effects gained through recombination in regulatory elements and fitness effects governed by individual genes. Thus, our project aims for a better understanding of the rapid evolution of host jumps through hybridization.

• DFG Programme: Priority Programmes
• International Connection: Austria, Norway, Sweden, Switzerland, United Kingdom, USA

Projects

• Adaptive evolution of immune gene families: origin, diversification and diversity of the NLR genes in zebrafish (Applicants Leptin, Ph.D., Maria ;  Wiehe, Thomas )
• Alien gene introgression promotes rapid adaptation: an unconscious experiment on Fire-bellied toad (Bombina bombina) at the northern edge of its distribution range (Applicant Tiedemann, Ph.D., Ralph )
• Coevolution in action in host and parasite genomes (Applicant Tellier, Aurélien )
• Comparative mechanistic elucidation of adaptation of Sporisorium reilianum to its host plants maize and sorghum (Applicant Schirawski, Jan )
• Constraints on Rapid Adaptation in Sticklebacks: availability & maintenance of genetic variation used in adaptation to freshwater environments. (Applicant Jones, Felicity )
• Coordination Funds (Applicant Schmid, Karl )
• Coordination project of the Priority Program SPP1819 - Rapid evolutionary adaptation (Applicants Schmid, Karl ;  Tellier, Aurélien )
• Experimental evolution of the co-adaptation of mais and its pathogen Exserohilum turcicum (Applicant Schmid, Karl )
• Exploring the molecular mechanisms that drive rapid evolutionary adaptations in the “one-speed" genome of the phytopathogenic barley powdery mildew fungus (Applicant Panstruga, Ralph )
• Genetic and epigenetic mechanisms of rapid host adaptation in the aphid parasitoid Aphidius ervi (Applicants Gadau, Jürgen ;  Schrader, Lukas )
• Genetic basis of metabolic and phenotypic plasticity and its relation to plant fitness (Applicants Laitinen, Roosa ;  Nikoloski, Ph.D., Zoran )
• Host virus coevolution – demography versus selection in the face of multiple stressors (Applicant Becks, Lutz )
• Interplay of pathogens, microRNAs, and regulation of resistance gene transcript abundance for rapid evolutionary responses in plants. (Applicant Rose, Laura )
• Modeling and inference of genomic signatures of polygenic selection driving fast adaptation (Applicant Stephan, Wolfgang )
• Population genomics of antibiotic resistance evolution (Applicant Schulenburg, Hinrich )
• Rapid adaptation of signaling networks in the fungal Pathogen Magnaporthe oryzae (Applicants Jacob, Stefan ;  Tenzer, Stefan )
• Rapid adaptive change through high recombination rates in eusocial insects (Applicants Oettler, Jan ;  Schrader, Lukas )
• Rapid evolution of gene regulation (Applicant Parsch, John )
• Rapid evolutionary adaptation to heavy metal-polluted soils in plant species of the genus Arabidopsis (Applicant Krämer, Ute )
• Rapid seasonal thermal adaptation in Chironomus riparius (Applicant Pfenninger, Markus )
• The contribution of vesicle-mediated DNA transfer to rapid adaptation (Applicant Dagan, Tal )
• The effects of ancestral plasticity and genetic assimilation on convergence and the diversification of East African cichlid fishes (Applicant Meyer, Axel )
• The molecular basis of phenotypic plasticity and genetic assimilation in rapidly evolving lineages of East African cichlid fishes (Applicant Meyer, Axel )
• The role of epigenetic inheritance in rapid evolutionary adaptation of invasive plants (Applicants Joshi, Jasmin ;  van Kleunen, Mark )
• The role of phenotypic plasticity for rapid evolutionary adaptation: theoretical and experimental approaches using Tribolium castaneum and Bacillus thuringiensis. (Applicant Kurtz, Joachim )
• The role of recombination in rapid adaptive evolution of fungal plant pathogens: Integrating demographic models, inferences of natural selection and population recombination maps (Applicant Holtgrewe-Stukenbrock, Ph.D., Eva )
• Unravelling tripartite species co-evolution under environmental change: can prophages accelerate bacterial virulence evolution? (Applicant Roth, Olivia )

• Spokesperson: Professor Dr. Karl Schmid