Leafcutter Ant Farmers Prevent Loss of Edible Symbiotic Structures by Maintaining Allelic Diversity in Their Multinucleate Fungal Crop.

Authors

Asta Rødsgaard-Jørgensen, Caio Leal-Dutra, Vasilis Kokkoris, Jonathan Z Shik

Published in

Molecular ecology. Volume 35. Issue 13. Pages e70458.

Abstract

Leafcutter ants farm the domesticated fungal cultivar Leucoagaricus gongylophorus in subterranean nests containing up to hundreds of discrete garden chambers. The fungal cultivar produces edible symbiotic structures called gongylidia (nutritious swollen hyphal cells consumed by the ants) and expresses a form of polyploidy (multiple, genetically distinct nuclei per fungal cellular compartment). Yet, the fungus is also thought to lack the typical innate mechanisms for distributing these nuclei across its mycelial network of connected hyphal cells. Because new garden chambers are seeded by clonal fungal fragments from existing chambers, this raises questions about whether and how nuclear diversity is maintained across chambers within a colony. We hypothesized: (1) that mycelial fragmentation causes genetic and phenotypic instability in isolated fungal cultivar inoculates, but (2) that these variables remain stable when actively farmed by ants. We found that experimentally fragmented fungal isolates in Petri dishes lost gongylidium production and had higher growth rates. Microsatellite analyses confirmed that these phenotypic changes coincided with loss of alleles and fluorescence microscopy showed that gongylidium incompetency coincided with reduced nucleus numbers per cellular compartment. In contrast, natural fragmentation by ants in free-ranging rainforest colonies coincided with minimal genetic divergence across garden chambers, even as divergence increased slightly with chamber distance. By integrating field and laboratory data, these results support: (1) that gongylidium production depends on genetic heterozygosity and multinuclearity, and (2) that ant farmers can maintain this genetic diversity. Resolving these stabilizing mechanisms will be crucial for understanding the genome evolution underlying a naturally selected crop domestication system.

PMID:
42400366
Bibliographic data and abstract were imported from PubMed on 04 Jul 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.