author={Adriane N. M. Bot and Stephen A Rehner and Jacobus J. Boomsma},
Abstract We investigate the nature and duration of incompatibility between certain combinations of Acromyrmex leaf‐cutting ants and symbiotic fungi, taken from sympatric colonies of the same or a related species. Ant‐fungus incompatibility appeared to be largely independent of the ant species involved, but could be explained partly by genetic differences among the fungus cultivars. Following current theoretical considerations, we develop a hypothesis, originally proposed by S. A. Frank, that… 

Specificity of the mutualistic association between actinomycete bacteria and two sympatric species of Acromyrmex leaf‐cutting ants

The finding that individual colonies cultivate a single actinomycete strain is in agreement with predictions from evolutionary theory on host–symbiont conflict over symbiont mixing, but indicates that there may be constraints on the effectiveness of the bacterial symbionts on an evolutionary timescale.

Population genetic signatures of diffuse co‐evolution between leaf‐cutting ants and their cultivar fungi

Investigation of partner fidelity at the population level in the attine ant–fungal cultivar mutualism implicates that mechanisms other than partner fidelity feedback play important roles in stabilizing the leafcutter ant‐fungus mutualism over evolutionary time.

Symbiont fidelity and the origin of species in fungus-growing ants

For ants and associated fungi in the Cyphomyrmex wheeleri species group, it is shown that each ant species has been exclusively associated with a single fungal cultivar 'species' for millions of years, even though alternative cultivars are readily available, and that rare shifts to new cultivar are associated with ant speciation.

Symbiont recognition of mutualistic bacteria by Acromyrmex leaf-cutting ants

It is shown that Acromyrmex leaf-cutter ants are able to differentiate between their native actinomycete strain and a variety of foreign strains isolated from sympatric and allopatric Acrom Myrmex species, in addition to strains originating from other fungus-growing ant genera, suggesting that symbiont recognition may play a crucial role in the fungus- growing ant–bacterium mutualism.

Extensive exchange of fungal cultivars between sympatric species of fungus‐growing ants

A phylogenetic analysis of 72 cultivars propagated by two fungus‐growing ant species coexisting sympatrically in central Panama indicates that cultivar exchanges between the two ant species occur routinely throughout ecological time and that coevolutionary processes between ants and their fungi are more diffuse than previously assumed.

Cooperation, conflict, and coevolution in the attine ant-fungus symbiosis

It is shown that interspecific cultivar switches caused a significant decline in worker number, garden biomass, and the number of reproductives produced by colonies, in contrast, these effects were not seen in intraspecific switches.

Fungus-gardening ants prefer native fungal species: Do ants control their crops?

It is suggested that the fungal strain cultivated by a colony imprints the attending ants, and this imprinting modifies ant behavior so that the ants prefer their original cultivar even when experimentally forced to grow a foreign cultivar for several weeks.

Non-specific association between filamentous bacteria and fungus-growing ants

The data suggest that the association between attine ants and their actinomycete symbionts is less specific then previously thought, probably reflecting an adaptation to a diverse community of microbial pathogens.

Cryptic sex and many-to-one coevolution in the fungus-growing ant symbiosis.

The present study provides the first evidence of recombination in attine cultivars, contradicting widely held perceptions of obligate clonality and document long-distance horizontal transmission of symbionts between leaf-cutter ant species on mainland Central America and South America and those endemic to Cuba, suggesting both lack of pairwise coevolutionary specificity in ant/cultivar interactions and dispersal of symbions independent of their ant hosts.

Genetic Diversity of Fungi Occurring in Nests of Three Acromyrmex Leaf-cutting Ant Species from Córdoba, Argentina

A genetic similarity analysis of all fungi isolated from 16 fungus gardens of three Acromyrmex species in Córdoba, Argentina, using intersimple sequence repeat (ISSR) as genetic markers finds a high interclone polymorphism, with a few bands shared by the clones.




Geographic variation in the mutualism between the legume Amphicarpaea bracteata and its nitrogen‐fixing root nodule bacteria was analyzed and suggested that adaptive variation in symbiotic compatibility has evolved without strictly parallel divergence in the two species.

Mutualism in Metapopulations of Legumes and Rhizobia

The structure of geographic variation in natural populations of the annual legume Amphicarpaea bracteata, together with patterns of variation in symbiotic fitness, is consistent with the interpretation that a mosaic pattern of differentiation may exist.

Fungus-growing ants use antibiotic-producing bacteria to control garden parasites

A new, third mutualist in this symbiosis is described, a filamentous bacterium (actinomycete) of the genus Streptomyces that produces antibiotics specifically targeted to suppress the growth of the specialized garden-parasite Escovopsis.

The Origin of the Attine Ant-Fungus Mutualism

The attine ant-fungus mutualism probably arose from adventitious interactions with fungi that grew on walls of nests built in leaf litter, or from a system of fungal myrmecochory in which specialized fungi relied on ants for dispersal and in which the ants fortuitously vectored these fungi from parent to offspring nests prior to a true fungicultural stage.

The agricultural pathology of ant fungus gardens.

The increased virulence of pathogens associated with ancient asexual cultivars suggests an evolutionary cost to cultivar clonality, perhaps resulting from slower evolutionary rates of cultivars in the coevolutionary race with their pathogens.

Garden sharing and garden stealing in fungus-growing ants

To investigate whether garden loss may induce ants to obtain a replacement cultivar from a neighboring colony (lateral cultivar transfer), pairs of queenright colonies of two Cyphomyrmex species were set up in two conjoined chambers.

The Evolution of Insect-Fungus Associations: From Contact to Stable Symbiosis

A plausible scenario for the evolution of stable symbiotic insect-fungus associations is discussed, in which the augmentation of digestive capacity through the ingestion of fungal enzymes is an important factor leading to the establishment of interdependence between the interacting partners in a mutualism.

Fungal vegetative compatibility.

  • J. Leslie
  • Biology
    Annual review of phytopathology
  • 1993
Heterokaryon fonnation between different fungal individuals is an important component of many fungal life cycles and may serve as the first step in the parasexual cycle and the transmission of

Models of Symbiosis

  • S. Frank
  • Biology
    The American Naturalist
  • 1997
A tentative outline of concepts is proposed for the evolutionary genetics of symbiosis, which concerns the tension between the integrative and disruptive forces of kin selection, and the evolution of asymmetrical symbioses in which one species can dominate its partner.