Rise and fate of genetic variation
This project deals with fundamental evolutionary questions such as how genetic variation is introduced into individuals and populations. In addition, we aim to answer more general questions about basidiomycete biology, such as the moment of germline definition, the prevalence of monokaryons and dikaryons in nature, among other things.
Previously, we have primarily used fairy rings of the basidiomycete Marasmius oreades to investigate the rise and fate of new genetic variation in the fungal life cycle. Fairy rings are caused by a fungal mycelium growing beneath the soil surface in a circular pattern. They are useful because it is easy to determine where a fungal individual starts and ends. By comparing the genome sequences of different fruiting bodies of a fairy ring, new mutations can be identified. We trace how mutations are distributed spatially, in large scale across the ring, and small scale within different fruiting body tissues, as well as temporally over the years.
As of 2026, we are expanding this project to the whole of Marasmius, as well as the related genera Gymnopus, Collybiopsis, Mycetinis, and others. The primary objectives are to investigate if relatives to Marasmius oreades have a similar germline-sequestration system, and to investigate a potential link between the mutation rate and lifespan of mushroom species. For this we are isolating fungi into pure culture, growing them, and sequening their genomes and transcriptomes.
Group members involved in the Marasmius project: Boel Olsson, Jesper Svedberg, Markus Hiltunen Thorén, Matilde Fonseca, Peter Jan Vonk, Shalya Moodley