Our research focuses on two inter-related areas: sexual selection and the nature of genetic variance in natural populations. Sexual preferences for elaborate sexual displays and ornaments are thought to evolve because they benefit the choosing sex (usually females) genetically. For the genetic benefits to be possible there must be additive genetic variation (VA) for sexual ornaments, such that highly ornamented individuals can pass fitter genes on to the progeny of choosy individuals.
Mutations and genes interacting with parasites, such as genes of the major histocompatibility complex (MHC) are important sources of genetic variation for fitness, and are therefore an important focus of our research.
Sexual selection can also affect the amount of genetic variance in natural populations, for example by purging deleterious mutations from populations, which can decrease the cost of sexual reproduction and decrease the risk of population extinction. However, sexual selection also leads to divergent selection on sexes, which can increase sexually antagonistic genetic variation within populations.
Sexual selection often leads to the maintenance of alternative reproductive phenotypes (ARPs) within sexes. Evolution of ARPs, including its genetic aspects, is another area of our research.
Currently, our main study species include acarid mites, guppies and bank voles. See our current projects for more details.
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News & jobs
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Major histocompatibility complex class I diversity limits the repertoire of T cell receptors
The major histocompatibility complex (MHC) is central for self-/non–self-recognition and acquired immunity. The extreme polymorphism of MHC genes, promoted by parasite-mediated selection, contrasts with limited within-individual diversity. The prevailing explanation is a trade-off between increased pathogen recognition and the anti-autoimmune T cell receptor (TCR) depletion mechanism. However, the predicted inverse relationship between individual MHC diversity and TCR repertoire size has not yet been shown. Using a rodent species with a variable number of MHC genes, we detected such an effect for MHC class I, but not class II. Our results, reported in PNAS (Migalska et al. 2019), partially support the TCR depletion hypothesis, but also suggest additional, unexplored mechanisms that might be constraining ...
Posted Feb 26, 2019, 6:17 AM by Jacek Radwan
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Postdoc on sexual selection: evolve and resequence approach
Postdoc position in evolutionary biology is available for four years starting from 1st April 2018 in NCN-funded project aiming to investigate effect of sexual selection on genome-wide genetic variation using a powerful approach of experimental evolution coupled with genome re-sequencing. The candidate should hold PhD degree in biological sciences or computer sciences and should have significant achievements in the area of evolutionary biology, molecular genetics or bioinformatics, published in international scientific journals. The employment is offered for three years, starting ideally in April 2019, but it is negotiable. Please apply before 1 March 2019. Further information about the project and application procedure can be obtained from the project leader via email: jradwan@amu.edu.pl ...
Posted Jan 31, 2019, 7:15 AM by Jacek Radwan
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Do MHC supertypes promote trans-species polymorphism?
Trans-species polymorphism (TSP) arises when multiple allelic lineages that originated in an ancestral species
are maintained in descendant species. TSP is usually a transient phenomenon,
but at the MHC, TSP is common and seemingly long-term, leading to profound
discordance between genealogies of MHC alleles and species phylogenies. In
a recent paper, Lighten et al. offered a scenario in which TSP is maintained by
balancing selection acting on several functionally divergent MHC ‘supertypes’
(clusters of MHC alleles with similar physicochemical properties at their
antigen-binding sites, rather than on MHC alleles. The scenario is based on an empirical finding
that population-genetic structure by supertypes is significantly lower than
allele-based null expectations, and on simulations modelling MHC alleles ...
Posted Oct 22, 2018, 4:40 AM by Jacek Radwan
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