- Host-pathogen co-evolution
- Virus evolution
- MHC and sexual selection
- Evolutionary genetics of invasive species
- Evolution of host disease resistance and virulence
- Population genetics
Pathogens like viruses are important selective agents shaping the evolution and genomic structure of their hosts. But also hosts influence the evolution of their viruses, and host population structure and genetic diversity, for example shaped through habitat fragmentation or anthropogenic disturbances may influence the adaptive processes of viruses. About 100 years ago the Panama Canal was built and large areas of forest were flooded, leading to the separation of formally connected animal populations on smaller islands. Using the example of a small mammal, the Tome’s spiny rat (Proechimys semispinosus) and genome-wide SNPs I am investigating how the population structure, genetic diversity and anthropogenic disturbance influences the host and it’s virus diversity in wild animals.
I further study molecular genetic adaptive processes and natural co-evolution between European rabbits (Oryctolagus cuniculus) and the rabbit haemorrhagic disease virus (RHDV) in Australia. The project is based at the University of Adelaide, where I am also holding an affiliate position with the Invasion Ecology Group with Phill Cassey. After their introduction in the mid-19th century, rabbits quickly spread and developed huge populations causing extensive ecological and economical damage. RHDV is highly virulent for rabbits and after its introduction to Australia in 1995 it reduced invasive rabbit populations strongly. I am interested in the epidemiological and genetic adaptations of the virus as well as in the genetic adaptations that occurred in rabbits since introducing RHDV to Australia.
On the host side, pathogen susceptibility is to a large extant determined by the diversity of the genes of the Major Histocompatibility Complex (MHC), encoding important components triggering immune reactions, and suitable markers for studying pathogen-driven selection. In bottlenecked populations such as invasive rabbits in Australia but also in endangered species, MHC variability may be reduced. The African Cheetah (Acinonyx jubatus) is a textbook example of how reduced MHC variability can lead to the absence of immune reactions after skin graft experiments. Wild Namibian Cheetahs, however, do not seem to have strongly compromised immune responses despite low MHC diversity. In a collaborative project with the Institute for Zoo and Wildlife Research (IZW, Berlin) we are investigating the effects of MHC diversity on the expression level in wild Cheetahs. This approach will help us to understand whether the evolutionary role of MHC diversity goes beyond allelic variability which would offer an explanation as to how wild cat species might have avoided an impaired immunocompetence, despite showing low MHC diversity.
My research is funded by DFG Priority Program ‘Host-Parasite Coevolution – Rapid reciprocal adaptation and its genetic basis’ (SPP 1399, DFG Sommer SO 428/7-1) and by the DFG Priority Program SPP 1596/2 Ecology and species barriers in emerging infectious diseases (SO 428/ 9-1, 9-2).
Iannella, A., Peacock, D., Cassey, P., Schwensow, N. (2018). Genetic perspectives on the historical introduction of the European rabbit (Oryctolagus cuniculus) to Australia. Biological Invasions. doi:10.1007/s10530-018-1849-2
Wells, K., Fordham, D. A., Brook, B. W., Cassey, P., Cox, T., O'Hara, R. B., Schwensow, N. I. (2018). Disentangling synergistic disease dynamics: Implications for the viral biocontrol of rabbits. Journal of Animal Ecology, 00, 1-11. doi:https://doi.org/10.1111/1365-2656.12871
Schwensow N, Castro-Prieto A, Wachter B, Sommer S (2019) Immunological MHC supertypes and allelic expression: how low is the functional MHC variability in wild endangered Namibian cheetahs? Conservation Genetics. In press (08.01.2019).
Schwensow, N., C. J. Mazzoni, E. Marmesat, J. Fickel, D. Peacock, J. Kovaliski, R. Sinclair, P. Cassey, B. Cooke & S. Sommer (2017) High adaptive variability and virus-driven selection on major histocompatibility complex (MHC) genes in invasive wild rabbits in Australia. Biological Invasions, 19, 1255-1271.
Schwensow, N., H. Detering, S. Pederson, C. Mazzoni, R. Sinclair, D. Peacock, J. Kovaliski, B. Cooke, J. Fickel & S. Sommer (2017) Resistance to RHD virus in wild Australian rabbits: comparison of susceptible and resistant individuals using a genome-wide approach. Molecular Ecology, 26: 4551-4561.
Pearson, S. K., S. S. Godfrey, N. Schwensow, C. M. Bull & M. G. Gardner; (2017) Genes and group membership predict gidgee skink (Egernia stokesii) reproductive pairs. Journal of Heredity, 108: 369-378.
Wells, K., B. W. Brook, R. C. Lacy, G. J. Mutze, D. E. Peacock, R. G. Sinclair, N. Schwensow, P. Cassey, R. B. O'Hara & D. A. Fordham (2015) Timing and severity of immunizing diseases in rabbits is controlled by seasonal matching of host and pathogen dynamics. Journal of the Royal Society Interface, 12.
Schwensow, N., B. Cooke, J. Kovaliski, R. Sinclair, D. Peacock, J. Fickel & S. Sommer (2014) Rabbit haemorrhagic disease: virus persistence and adaptation in Australia. Evolutionary Applications, 7, 1056-1067.
Schwensow, N., B. Cooke, J. Fickel, W. Lutz & S. Sommer (2012) Changes in liver gene expression indicate genetic pathways associated with rabbit haemorrhagic disease infection in wild rabbits. The Open Immunology Journal, 5, 20-26.
Schwensow, N., J. Axtner & S. Sommer (2011) Are associations of immune gene expression, body condition and parasite burden detectable in nature? A case study in an endemic rodent from the Brazilian Atlantic Forest. Infection, Genetics and Evolution, 11, 23-30.
Schwensow, N., K. Dausmann, M. Eberle, J. Fietz & S. Sommer (2010) Functional associations of similar MHC alleles and shared parasite species in two sympatric lemurs. Infection, Genetics and Evolution, 10, 662-668.
Schwensow, N., M. Eberle & S. Sommer (2010) Are there Ubiquitous Parasite-driven Major Histocompatibility Complex Selection Mechanisms in Gray Mouse Lemurs? International Journal of Primatology, 31, 519-537.
Schwensow, N., M. Eberle & S. Sommer (2008) Compatibility counts: MHC-associated mate choice in a wild promiscuous primate. Proceedings of the Royal Society B: Biological Sciences, 275, 555- 564.
Schwensow, N., J. Fietz, K. Dausmann & S. Sommer (2008) MHC-associated mating strategies and the importance of overall genetic diversity in an obligate pair-living primate. Evolutionary Ecology, 22, 617-363.
Schwensow, N., J. Fietz, K. Dausmann & S. Sommer (2007) Neutral versus adaptive variation in parasite resistance: importance of MHC-supertypes in a free-ranging primate. Heredity, 99, 265-277.
- Dr. Nina Schwensow
Institute of Evolutionary Ecology
and Conservation Genomics
University of Ulm
Email: nina.schwensow () uni-ulm.de