People of Johannesson Lab

Principal Investigator

Hanna Johannesson

I am Professor in Evolutionary genetics. I established my own research group at Uppsala University in 2005, after a PhD at the Swedish Agricultural University and a postdoc at University of California at Berkeley. I achieved an Associate Professorship (docentur) in 2006 and between 2007 and 2013 I held a senior research position (rådsforskartjänst) funded by the Swedish Research Council (VR). Since December 2013 I am a full professor. My research interest lies in the interface between mycology and evolutionary biology. In particular I am interested in using fungi as models to explore general evolutionary questions such as natural selection operating at multiple levels in the biological hierarchy, the causes and consequences of symbioses and switches in reproductive mode. Having obtained funding from VR and the European Research Council (ERC) has recently given me the opportunity to dive into the evolutionary consequences of meiotic drive.

Graduate Students

Sandra Lorena Ament Velásquez

I joined Hanna’s group as a PhD-student in the fall of 2015. I am interested in the population dynamics of fungal meiotic drive elements (the Spore killers), in particular under which circumstances they may invade a population or go to fixation, and what changes cause birth and death of new killers over evolutionary time. I am currently addressing the Spore killers from a comparative and population genomics perspective. I am also greatly interested in molecular systematics, population genetics, speciation, and mating dynamics of lichenized fungal and marine invertebrates.

Markus Hiltunen

I started my PhD studies in September 2016 and work on the fairy ring forming mushroom Marasmius oreades. The main topics of my PhD project are intraorganismal variation and nuclear interactions in this fungus. I am interested in the processes that generate new variation outside of the sexual cycle, the consequences of having two autonomous nuclei in each cell, and also fungal biology, genomics and evolution in general.

Post Docs

Ivain Martinossi-Allibert

I am a theoretician interested in genetic conflicts related to sexual reproduction and the evolution of sex. I joined the group early in 2019 to build a population genetics model of the spore killing genes found in the Podospora and Neurospora genus. Spore killers are a category of meiotic drivers, selfish genetic elements that can spread in a population even though they impose a fitness cost to their hosts. Understanding how meiotic drivers behave in natural population will be an important step in our understanding of the living world, with many potential applications. The Johannesson group is working on this question with a comprehensive set of methods including field studies and genomics analyses, and my current project is to complement these with a theoretical framework.

Sara Hosseini

I joined the Johannesson group in September 2015. In my research I study the interactions of nuclei in Neurospora tetrasperma that is a heterokaryotic fungus. A heterokaryon is a tissue type composed of cells containing genetically different nuclei. Recent findings from the Johannesson research group suggest that nuclei in a fungal heterokaryon interact at the gene expression level to optimize the life cycle. We hypothesize that the interaction is mediated at the epigenetic level. I test this hypothesis by analyzing smallRNAs, DNA methylation and histone modification of the two nuclear types during vegetative and sexual life stages.

Diem Nguyen

I joined the Johannesson group in July 2016 and work on transposable elements, which are mobile genetic sequences that contribute to host genome architecture, gene expression and evolution. As a response, Ascomycete fungi have evolved genome defense systems such as repeat-induced point mutation (RIP), which is a gene-silencing mechanism that mutates repetitive sequences including transposable elements. I am currently characterizing transposable elements in Neurospora species to study the evolution of RIP along Neurospora phylogeny.

Aaron Vogan

I joined the Johannesson group in June 2016. I am broadly interested in fungal evolution with regards to speciation. Currently, I am studying meiotic drive in the both Neurospora and Podospora species of filamentous fungi. The goal of which is to understand the impact of meiotic drive on the population structure of these species.

Former members of the group