Symbiosis%20and%20coevolution%20in%20insect-microbe%20communities

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Symbiosis and coevolution in insect-microbe
communities Nicole Gerardo Emory University,
Department of Biology Nancy Lowe, Ben Parker
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(No Transcript)
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(Kolenbrander et al. Micro and Molec Biol Rev
2002)
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The nature of parasite specialization in the
fungus-growing ant symbiosis Dr. Nicole
Gerardo Emory University, Department of
Biology Nancy Lowe, Ben Parker
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Ants their mutualistic fungal cultivars
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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
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Ants their mutualistic fungal cultivars
Leaf-Cutter Ants
Lower Ants
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Ants their mutualistic fungal cultivars
Coevolution Interactions between species over
time lead to adaptations by both species in
response to one another
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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
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Ants their mutualistic fungal cultivars
Actinomycete bacteria that produce antibiotics
that inhibit Escovopsis
Escovopsis, a genus of parasitic fungus that
attacks the ants fungal cultivars
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Ants their mutualistic fungal cultivars
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Healthy fungus-growing ant garden
Garden devastated by Escovopsis
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(No Transcript)
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Escovopsis spp. specialize on host clades.
Escovopsis
Cultivars
Ants
(Currie et. al 2003)
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Escovopsis Pathogen Phylogeny
brown
brown
yellow
pink
pink
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Escovopsis Pathogen Phylogeny
brown
brown
pink
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• 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.

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• Leaf-Cutter
• Brown Escovopsis

• Apterostigma
• Brown Escovopsis

Apterostigma colony on a tree branch
Partially excavated leaf cutter colony
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pathogen - cultivar interactions
cultivar
pathogen
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pathogen - cultivar interactions
cultivar
pathogen
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pathogen - cultivar interactions
cultivar
pathogen
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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
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No Inhibition
Inhibition
No Attraction
Attraction
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pathogen
Leaf Cutter
Apterostigma

e1 e2 e3 e4 e5 e6 e1 e2 e3 e4 e5 e6
c1
c2
c3
c4
c5
c6
c1
c2
c3
c4
c5
c6
Apterostigma
cultivar
Leaf Cutter
Attraction
Inhibition
Inhibition Attraction
Neither
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pathogen
Leaf Cutter
Apterostigma

e1 e2 e3 e4 e5 e6 e1 e2 e3 e4 e5 e6
c1
c2
c3
c4
c5
c6
c1
c2
c3
c4
c5
c6
Apterostigma
cultivar
Leaf Cutter
Attraction
Inhibition
Inhibition Attraction
Neither
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pathogen
Leaf Cutter
Apterostigma

e1 e2 e3 e4 e5 e6 e1 e2 e3 e4 e5 e6
c1
c2
c3
c4
c5
c6
c1
c2
c3
c4
c5
c6
Apterostigma
cultivar
Leaf Cutter
Attraction
Inhibition
Inhibition Attraction
Neither
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pathogen
Leaf Cutter
Apterostigma

e1 e2 e3 e4 e5 e6 e1 e2 e3 e4 e5 e6
c1
c2
c3
c4
c5
c6
c1
c2
c3
c4
c5
c6
Apterostigma
cultivar
Leaf Cutter
Attraction
Inhibition
Inhibition Attraction
Neither
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Escovopsis Phylogeny
brown
brown
pink
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Ants their mutualistic fungal cultivars
Actinomycete bacteria that produce antibiotics
that inhibit Escovopsis
Escovopsis, a genus of parasitic fungus that
attacks the ants fungal cultivars