Understanding how genetic factors affect host-pathogen dynamics is essential to assess the risk of disease outbreaks, mortality, and transmission among species. Many wildlife and human pathogens frequently switch host species and vary remarkably in pathogenicity, showing little or no effects in some species, but causing dramatic mass mortalities in others. However, despite having important implications both for conservation of wild animals and for human public health, drivers of pathogen susceptibility, transmission, and evolution in the wild are poorly understood.

I am currently a postdoc in the Marine Mammal Group at GLOBE Institute, University of Copenhagen, where I study how variation in key immune system genes affects susceptibility to viral diseases in wild mammals, using Northern European seal populations as a model system. My studies also investigate whether historic bottleneck events have purged vital genetic variation and increased the susceptibility of certain populations to viral epidemics.

During my PhD, I studied natural selection on the molecular level in a closely monitored wild population of great reed warblers Acrocephalus arundinaceus in Kvismaren in south Central Sweden. Previous results from this study system have shown that the condition and health of individual birds may be important for social mate choice and thus fitness. My primary focus was on immune system genes of the major histocompatibility complex (MHC), as these are good candidates to both influence health and provide genetic advantages, because of their central role in the function of adaptive immunity. I compared MHC diversity to individual fitness (and a number of fitness related life-history parameters), with particular focus on sexually antagonistic effects (Roved et al., 2017, 2018). Future studies in this system will include associations between within-individual MHC variation and telomere attrition and susceptibility to avian malaria.

As a side project, I study the mate attraction song of male great reed warblers. Previous analyses of recordings from this population have revealed a correlation between the size of the song repertoire and the relative offspring survival, which implies that the song might be an indicator of genetic quality and that females may select males with a large song repertoire to achieve indirect benefits to their offspring (e.g. Hasselquist et al., 1996). I am interested in trying to identify the specific benefits related to song quality, as these may be related to intra-specific variation in immune function (the ‘immunocompetence handicap hypothesis’ – Hamilton & Zuk, 1982).


References
Hamilton & Zuk, 1982. Heritable true fitness and bright birds - a role for parasites. Science.
Hasselquist, Bensch & von Schantz, 1996. Correlation between male song repertoire, extra-pair paternity and offspring survival in the great reed warbler. Nature.
Roved, Hansson, Tarka, Hasselquist & Westerdahl, 2018. Evidence for sexual conflict over MHC diversity in a wild songbird. Proceedings of the Royal Society B.
Roved, Westerdahl & Hasselquist, 2017. Sex differences in immune responses: Hormonal effects, antagonistic selection, and evolutionary consequences. Hormones and Behavior.