News & jobs

Here you can read news, announcements and job positions related to our group.

Sexual selection predicts the persistence of populations within altered environments

posted Aug 6, 2019, 3:18 AM by Mateusz Konczal   [ updated Aug 6, 2019, 4:01 AM ]

The effect of sexual selection on species persistence remains unclear. A fascinating article, recently published in Ecology Letters, suggests that dung beetle species with more competition among males for mating are less likely go extinct (Parrett et al. 2019). The team followed 34 different species of tunneller dung beetle in the tropical rainforest of Sabah in Malaysian Borneo. The results showed that species with horns were more likely to persist in the disturbed environments than were those without horns, and in the most disturbed environment, oil palm plantation, all of the 11 species that remained had horns. Furthermore, the researchers found that among the species with horns, those with relatively large horns for their body size were more likely to persist and had larger population sizes. This study represents the first evidence from a field system of population-level befit from pre-copulatory sexual selection.

The first author of this article, Jonathan Parrett, recently joined our group to investigate effect of sexual selection genome-wide patterns of genetic variation in the bulb mite. Congratulations Jon!



PhD position: Genomics of invasion in Trinidadian guppies

posted Jun 21, 2019, 5:00 AM by Mateusz Konczal   [ updated Jun 23, 2019, 11:39 PM ]

The Evolutionary Biology Group is recruiting a PhD student for an NCN-funded project that will investigate genomic consequences of artificial introduction, population expansion and population replacement in the Trinidadian guppy. The successful candidate will take part in all parts of the project including sampling fish on Trinidad and Tobago and analyzing population genomic data.  

Background: A major aim in evolutionary biology is to quantify the effects that demographic history has had and can have on the patterns and dynamics of deleterious and adaptive variation. The project aims at validating theoretical predictions recently developed in this field, especially those related to population expansion and gene flow between species. To address these questions, we will perform large-scale genomic analyses of a population of guppies recently introduced into an area previously occupied only by its sister species. We will study how deleterious and adaptive variation shape the genomic landscape of introgression.

Job description: The PhD student will work in close collaboration with project leader (Mateusz Konczal) and a bioinformatician. There will be considerable flexibility in the scope of the student’s work within the overall main goals of the project. The student will learn simple molecular laboratory techniques, analyze population genomic data, perform population genomic simulations and will have the opportunity to go to Trinidad and Tobago to help local collaborators in sampling fish. S/he will be integrated in the vibrant, highly motivated international research team based at Adam Mickiewicz University in Poznan, Poland.

Requirements: The candidate should hold an MSc degree in biological sciences or computer sciences and should have a general interest in evolutionary biology. Experience with molecular lab techniques (specifically DNA extraction), programming and big data analyses are desirable though not required.

Financing: The position, starting from October 2019 (negotiable), is planned for three years with a stipend of PLN 4,500 (about 1,050 euro) per month. Extending this contract for extra two years will be possible with financing from local grant agencies.

How to apply: Applications should include a letter with a short description of your research interests, CV, summary of MSc work and/or other relevant projects. Future information about the project and application procedure can be obtained from the project leader via email: matusz.konczal(a)amu.edu.pl.

Please apply before 20.08.2019

Magdalena Migalska defends her thesis!

posted Jun 19, 2019, 6:18 AM by Mateusz Konczal   [ updated Jun 19, 2019, 6:24 AM ]

Magdalena Migalska defended her PhD entitled “MHC genes copy number and TCR repertoire size in the bank vole: diversity, selection and the optimal hypothesis”. The thesis was submitted as a collection of three peer-reviewed articles published in Heredity (link), Scientific Reports (link) and PNAS (link). She will next come back to her beloved Krakow, to continue work on MHC genes at the Jagiellonian University. We feel that Krakow is so lucky to have her and we will certainly miss her in the lab. Congratulations Magda! 



Major histocompatibility complex class I diversity limits the repertoire of T cell receptors

posted Feb 26, 2019, 6:17 AM by Jacek Radwan

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 expansion of the MHC gene family.

Postdoc on sexual selection: evolve and resequence approach

posted Jan 31, 2019, 7:15 AM by Jacek Radwan

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 

 

Brief summary of the project:

Genetic variation is a fuel of evolution, therefore assessing the role of sexual selection in maintaining this variation is fundamental to our understanding of evolutionary processes occurring in sexual species.  The rate and extent of adaptation depend on available genetic variation, which sexual selection has long been thought to deplete. However, recent theory predicts that, contrary to the traditional view, sexual selection may actually increase genetic variation due to sexual antagonism and other trade-offs associated with evolution of costly sexually-selected traits. Yet, the effect of sexual selection on the amount of genetic variation segregating in populations has not been investigated empirically. The aim of the proposed project is to investigate effect of sexual selection on genome-wide genetic variation using a powerful approach of experimental evolution coupled with genome re-sequencing.

The project will use a species very well suited for this purpose, the bulb mite Rhizoglyphus robini, a well-established model in sexual selection research. The project will benefit from the fact that the genome of this species has recently been assembled and annotated.

Replicate populations will be allowed to evolve for about 20 generations under treatments differing in (i) sex ratio, and thus intensity of sexual selection and (ii) the frequency of males bearing an elaborated sexually-selected trait: thickened legs used for intrasexual contests. Previous research demonstrated that the trait is associated with increased ontogenetic  intersexual conflict and life history trade-offs. Genomes of mites from replicated experimental evolution lines will then be sequenced and used for testing whether evolution of costly, condition-dependent sexually selected traits depletes (as predicted by traditional theory) or helps to maintain genetic polymorphism in functional parts of the genome (amino-acid substitutions in protein coding genes, and nucleotide substitutions in cis-regulatory sequences). The results will be interpreted in the context of intragenomic variation in recombination rate, a major determinant of genetic variation. The variation in recombination rate will be estimated in the proposed project.

Do MHC supertypes promote trans-species polymorphism?

posted Oct 22, 2018, 4:30 AM by Jacek Radwan   [ updated Oct 22, 2018, 4:40 AM ]

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 as coordinates in paratope space. In our recent paper (https://www.nature.com/articles/s41467-018-06821-x ), we argue that the empirical patterns do not support a major role of supertypes in the maintenance of TSP, and that the theoretical arguments provided by Lighten et al. are based on disputable assumptions.

T-cell receptor (TCR) repertoire profiling in non-model species using high-throughput sequencing

posted Aug 21, 2018, 4:10 AM by Magdalena Migalska   [ updated Oct 22, 2018, 4:35 AM by Jacek Radwan ]

High-throughput sequencing (HTS) prompted development of novel, refined methods of analyzing immunological repertoires (e.g. immunoglobulins, TCRs). So far, despite a decade of progress, these techniques were mainly used in research involving model species and humans.

Recently, our group published an article in Scientific Reports describing first use of HTS in TCR repertoire sequencing in a non-model mammal (the bank vole, Myodes glareolusI). The article also presents our newly developed software: AmpliTCR and AmpliCDR3. Programs allow detailed quantitative and qualitative description of TCR repertoires without reference sequences. These tools should become particularly useful in the fields of comparative immunology, ecology and evolutionary biology, which often focus on non-model species.

PhD position starting 1st October 2018

posted May 22, 2018, 4:00 AM by Jacek Radwan   [ updated May 22, 2018, 4:01 AM ]

PhD position in evolutionary biology is available for four years starting from 1st October 2018 in NCN-funded project aiming to investigate the effect of sexual selection on genome-wide genetic variation using a powerful approach of experimental evolution coupled with genome re-sequencing.  The student will receive stipend of 4500 PLN/month and, in addition to carrying our research, will have opportunity to attend specialized courses for PhD students in English. The candidate should hold MSc degree in biological sciences or bioinformatics.

Further information about the project and application procedure can be obtained from the project leader via email: jradwan@amu.edu.pl

 

Brief summary of the project:

Genetic variation is a fuel of evolution, therefore assessing the role of sexual selection in maintaining this variation is fundamental to our understanding of evolutionary processes occurring in sexual species.  The rate and extent of adaptation depend on available genetic variation, which sexual selection has long been thought to deplete. However, recent theory predicts that, contrary to the traditional view, sexual selection may actually increase genetic variation due to sexual antagonism and other trade-offs associated with evolution of costly sexually-selected traits. Yet, the effect of sexual selection on the amount of genetic variation segregating in populations has not been investigated empirically. The aim of the proposed project is to investigate effect of sexual selection on genome-wide genetic variation using a powerful approach of experimental evolution coupled with genome re-sequencing.

The project will use a species very well suited for this purpose, the bulb mite Rhizoglyphus robini, a well-established model in sexual selection research. The project will benefit from the fact that the genome of this species has recently been assembled and annotated.

Replicate populations will be allowed to evolve for about 20 generations under treatments differing in (i) sex ratio, and thus intensity of sexual selection and (ii) the frequency of males bearing an elaborated sexually-selected trait: thickened legs used for intrasexual contests. Previous research demonstrated that the trait is associated with increased ontogenetic  intersexual conflict and life history trade-offs. Genomes of mites from replicated experimental evolution lines will then be sequenced and used for testing whether evolution of costly, condition-dependent sexually selected traits depletes (as predicted by traditional theory) or helps to maintain genetic polymorphism in functional parts of the genome (amino-acid substitutions in protein coding genes, and nucleotide substitutions in cis-regulatory sequences). The results will be interpreted in the context of intragenomic variation in recombination rate, a major determinant of genetic variation. The variation in recombination rate will be estimated in the proposed project.

Novel MHC alleles give their guppy hosts advantage in dealing with ectoparasites

posted Jan 18, 2018, 2:36 AM by Jacek Radwan   [ updated Jun 15, 2018, 5:33 AM ]

In our recent article "Immunogenetic novelty confers a selective advantage in host–pathogen coevolution" published in PNAS (read informal story behind the paper here), we demonstrate that MHC alleles to which Gyrodactylus flukes had no opportunity to adapt are associated with less severe infection in hosts. The major histocompatibility complex (MHC) is one of the most polymorphic gene families in the vertebrate genome, with natural selection actively promoting and maintaining variability. The exact mechanism/mechanisms responsible for these characteristics remain unclear, but identifying them is fundamental to our understanding of host–pathogen dynamics. Using targeted crosses of the model Trinidadian guppy, a tractable parasite, and exposure-controlled infection trials, we show that novel MHC variants are associated with less severe infections. Uniquely, our experimental design separates novel variant advantage from other modes of selection and confounding variables, such as individual MHC variability and genomic background. We thus demonstrated a fundamental process driving evolution of the vertebrate immune system, which helps explain the unique features of MHC genes. Reprints available on request from jraadwan[at]amu.edu.pl

New grants and stipends for our team members!

posted May 16, 2017, 6:40 AM by Mateusz Konczal   [ updated May 16, 2017, 7:06 AM by Piotr Bentkowski ]

Recently we received some grants and stipends!

PRELUDIUM is a National Science Center’s opportunity intended for pre-doctoral researchers about to embark on their scientific career. We are happy to announce that Aleksandra Łukasiewicz from our team received this grant for the project entitled Environmental quality and intensity of sexual conflict. The project aim to test the assumption that the low-quality food during development should reduce intensity of sexual conflict. Ola with her project was first in the ranking in the environmental biology & evolution panel (NZ8)! Congratulations Ola! Here you can find out more about the project.

START is a stipend from Foundation for Polish Sciences that is dedicated to young researchers, at the outset of their career, who have already achieved some success in their field.  This year foundation awarded 100 young researchers; 3 people with most highly rated research accomplishments received distinctions. One of them is Mateusz Konczal. Mateusz received this award for his work in evolve & resequence research. More about his work is published byPolish Press Agency (in polish).

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