Within, Between, and Across: The Genomic Structure and Stability of the Domesticated Fungal Cultivar of Leafcutter Ants, Leucoagaricus gongylophorus

PhD defence by Asta Rødsgaard-Jørgensen

Assessment Committee

Professor Michael Poulsen, Biology, University of Copenhagen (Chairperson)
Full Professor at Laboratory of Genetics Duur Kornelis Aanen, Wageningen, The Netherlands
Professor Hanna Sofia Johannesson, The Royal Swedish Academy of Sciences

Supervisors

Associate Professor Jonathan Z. Shik

Department

Department of Biology

Place

The defence is conducted as a hybrid defence.

To attend the defence in person:
Building: Niels Bohr building, Room: NBB 001-0-EF.000 - Margrethe Bohr,
Jagtvej 155 A, 2200 København N

To attend the defence online:
Please follow the link to attend the defence online: https://ucph-ku.zoom.us/j/65934018063?pwd=NUNoanplVW4wV21ISzh6NGVKS2dEdz09
MeetingID, if relevant: 659 3401 8063
Password, if relevant: 274819

Email address to gain access to the thesis: asta.roedsgaard@bio.ku.dk.
You will either receive a copy of the thesis or be informed where you can read a physical copy.
Recipients of copies of the thesis are not allowed to share or distribute it due to copyright compliance.

Short description of the thesis

Fungus-farming attine ants have cultivated fungal crops for ~60 million years, evolving increasingly sophisticated farming systems. The most advanced farmers, the leafcutter ants, cultivate the highly domesticated fungus Leucoagaricus gongylophorus, which contains multiple genetically distinct nuclei. Although this unusual genome structure is expected to be unstable over evolutionary time, it has persisted for millions of years. In my PhD research, I investigate how this fungal cultivar maintains genetic stability within the mycelium, between nuclei, and across colonies. My results show that genetic diversity is preserved through ant-mediated processes, nuclear-level regulation, and mycelial organization. These findings provide insights into how the genomic structure of a highly domesticated fungal crop has been maintained over millions of years of symbiosis with leafcutter ants.