Pseudonocardia are filamentous actinomycetes with ~6Mbp circular genomes, best known as vertically transmitted mutualists of fungus-growing attine ants. Leafcutter ant associated strains make polyene antifungals that are variants of nystatin A1, with additional hexose sugar groups. Less highly evolved attine ants are associated with Pseudonocardia strains that make depsipeptide antibiotics such as dentigerumycin. These organisms are generally slow growing and often only grow on agar plates. They are also difficult to genetically manipulate although they are amenable to conjugation from E. coli and mutations have been made using suicide vectors.
Image shows colonies of two different Pseudonocardia strains growing on agar plates and on the propleural plate of an Acromyrmex echinatior leafcutter ant (the white covering on the chest area).
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