Symbiosis and coevolution in insectmicrobe communities Nicole Gerardo

Symbiosis and coevolution in insectmicrobe communities Nicole Gerardo Emory University, Department of Biology Nancy Lowe, Ben Parker

(Kolenbrander et al. Micro and Molec Biol Rev 2002)

The nature of parasite specialization in the fungus-growing ant symbiosis Dr. Nicole Gerardo Emory University, Department of Biology Nancy Lowe, Ben Parker

Ants & their mutualistic fungal cultivars

Ants & their mutualistic fungal cultivars Symbiosis close, long-term interactions between biological species Coevolution Interactions between species over time lead to adaptations by both species in response to one another

Ants & their mutualistic fungal cultivars Lower Ants Leaf-Cutter Ants

Ants & their mutualistic fungal cultivars Coevolution Interactions between species over time lead to adaptations by both species in response to one another

Ants & their mutualistic fungal cultivars Escovopsis, a genus of parasitic fungus that attacks the ants’ fungal cultivars Coevolution Interactions between species over time lead to adaptations by both species in response to one another

Ants & their mutualistic fungal cultivars Escovopsis, a genus of parasitic fungus that attacks the ants’ fungal cultivars Actinomycete bacteria that produce antibiotics that inhibit Escovopsis

Ants & their mutualistic fungal cultivars

Healthy fungus-growing ant garden Garden devastated by Escovopsis

Escovopsis spp. specialize on host clades. Escovopsis Cultivars Ants (Currie et. al 2003)

Escovopsis Pathogen Phylogeny brown yellow pink

Escovopsis Pathogen Phylogeny brown pink

Leaf-Cutter Brown Escovopsis • Found only in colonies of leaf cutter ants and their close relatives • These ants cultivate fungi in the family lepiotaceae. Apterostigma Brown Escovopsis • Found only in colonies of Apterostigma spp. lower ants. • These ants cultivate fungi in the family pterulaceae, which is distantly related to the fungi cultivated by leaf cutter ants.

Leaf-Cutter Brown Escovopsis Partially excavated leaf cutter colony Apterostigma Brown Escovopsis Apterostigma colony on a tree branch

pathogen - cultivar interactions cultivar pathogen

pathogen – cultivar experimental design cultivar Interact… 12 pathogen isolates (6 Leaf cutter & 6 Apterostigma) With… 12 cultivar isolates (6 Leaf cutter & 6 Apterostigma) Total Bioassays: 144 pathogen

Attraction No Attraction Inhibition No Inhibition

pathogen Leaf Cutter Apterostigma e 1 e 2 e 3 e 4 e 5 e 6 Apterostigma c 2 c 3 c 4 c 5 c 6 c 1 Leaf Cutter cultivar c 1 c 2 c 3 c 4 c 5 c 6 Attraction Inhibition & Attraction Neither

Escovopsis Phylogeny brown pink

Ants & their mutualistic fungal cultivars Escovopsis, a genus of parasitic fungus that attacks the ants’ fungal cultivars Actinomycete bacteria that produce antibiotics that inhibit Escovopsis