Project description:Leaf-cutting ants of the genera Acromyrmex and Atta live in mutualistic symbiosis with a basidiomycete fungus (Leucocoprinus gongylophorus), which they cultivate as fungal gardens in underground nest chambers. The ants provide the fungus with a growth substrate consisting of freshly cut leaf fragments. After new leaf fragments are brought into the nest, the ants chew them into smaller pieces and apply droplets of fecal fluid to the leaf pulp before depositing this mixed substrate in the fungus garden and inoculating it with small tufts of mycelium from older parts of the garden. Previous work has shown that the fecal fluid contains a range of digestive enzymes including proteases, amylases, chitinases, cellulases, pectinases, hemicellulases and laccases, and that most of these enzymes are produced by the fungal symbiont in specialized structures called gongylidia that the ants eat. After ingestion, the enzymes apparently pass unharmed through the alimentary channel of the ants and end up in the fecal fluid. Most likely this complex system is an adaptation of the ant-fungus symbiosis to a herbivorous lifestyle, as the ancient ancestors of the ants and the fungus lived as hunter-gatherers and saprotrophs, respectively. The promise of fecal fluid for getting insight into the molecular adaptations that enables the ant-fungus holosymbiont to live as a herbivore, led us to investigate the fecal fluid proteome using LC-MS/MS in order to get a more comprehensive picture of the repertoire of proteins present.
Project description:Leaf-cutter ants use fresh plant material to cultivate an obligate mutualistic fungus Leucoagaricus gongylophorus in specialized fungus gardens to access and transform nutrients from plant biomass that would otherwise be unavailable to the ants. Here, we evaluated the lipidomic differences between the leaves feeding the gardens, gongylidia produced by the fungus to feed the ants, and spatially-resolve regions of the fungus garden at initial to advanced stages of leaf degradation.
Project description:Leaf-cutter ants use fresh plant material to cultivate an obligate mutualistic fungus Leucoagaricus gongylophorus in specialized fungus gardens to access and transform nutrients from plant biomass that would otherwise be unavailable to the ants. Here, we evaluated the lipidomic differences between the leaves feeding the gardens, gongylidia produced by the fungus to feed the ants, and spatially-resolve regions of the fungus garden at initial to advanced stages of leaf degradation.
2019-10-30 | MSV000084520 | GNPS
Project description:Symbiotic bacterial communities of fungus-farming ants
Project description:Instrument data for publication "Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens", ISME J. 2012 Sep; 6(9): 1688-1701. PMID: 22378535. PMCID: PMC3498920
2018-05-25 | MSV000082408 | MassIVE
Project description:Genomic signatures of domestication in fungus-farming ants symbiosis
Project description:Metabolites extracted from the thorax of leaf-cutter ants that contain the bacteria Pseudonocardia, analyzed with LC-MS and LC-MS/MS
Project description:The biting behavior observed in Carpenter ants infected by the specialized fungus Ophiocordyceps unilateralis s.l. is an example of a complex host behavioral manipulation by parasite. Though parasitic manipulation of host behavior is generally assumed to be due to the parasite’s gene expression, few studies have set out to test this. We experimentally infected Carpenter ants to collect tissue from both parasite and host during the time period when manipulated biting behavior is experienced. Upon observation of synchronized biting, samples were collected and subjected to RNA-Seq analyses. We also sequenced and annotated the O. unilateralis s.l. genome as a reference for the fungal reads. Our mixed transcriptomics approach, together with a comparative genomics study, shows that the majority of the fungal genes that are up-regulated during manipulated biting behavior are unique to the O. unilateralis s.l. genome. This study furthermore reveals that the fungal parasite might be regulating immune- and neuronal stress responses in the host during manipulated biting, as well as impairing its chemosensory communication and causing apoptosis. Moreover, we found genes up-regulated during manipulation that putatively encode for proteins with reported effects on behavioral outputs, proteins involved in various neuropathologies, and proteins involved in the biosynthesis of secondary metabolites such as alkaloids.
Project description:Mass spectrometry imaging is a powerful analytical technique for detecting and determining spatial distributions of molecules within a sample. Typically, mass spectrometry imaging is limited to the analysis of thin tissue sections taken from the middle of a sample. In this work, we present a mass spectrometry imaging method for the detection of compounds produced by bacteria on the outside surface of ant exoskeletons in response to pathogen exposure. Fungus-growing ants have a specialized mutualism with Pseudonocardia, a bacterium that lives on the ants’ exoskeletons and helps protect their fungal garden food source from harmful pathogens. The developed method allows for visualization of bacterial-derived compounds on the ant exoskeleton. This method demonstrates the capability to detect compounds that are specifically localized to the bacterial patch on ant exoskeletons, shows good reproducibility across individual ants, and achieves accurate mass measurements within 5 ppm error when using a high-resolution, accurate-mass mass spectrometer.