Cameron Currie: ant farmers

Cameron Currie Ancient mutualism for fungi and ants – something I love to learn more about.  Great system for mutualism of animals and microbes. Showing Chapela et al figure of co-evolution.

There is also a parasite that specializes on the ant-fungal interaction. Escovopsisco-evolves with ant and fungus. So a triparte symbiosis. But Wait. The he introduces the 4th player, where the actinobacter which produces antibiotics to protect the ants. Specialized organs for culturing the bacteria which are all over the body which are specialized opening for crypts for the filamentous bacteria. 6-8 years ago, 4-way interactions.

Work in the GLBRC is currently to understanding of the breakdown of the plant biomass. The fungus that is cultured by the ants is not cellulosic. Mature colonies can produce huge amounts of biomass but it gets broken down. See if cellulose is decomposed in the fungus garden, and is being broken down. Lignin is not really getting destroyed though?

Project with the JGI is “Fungus Garden Metagenomics”. 16S metagenome. 400M bp from community sequencing. Interesting bacteria found in the fungal garden. lots of species from the gardens “Cellulomonas” sounds like it could be good hit… =)

The top hit is Klebsiella an N-fixer, cellulose-degrader and is a Gamma-proteobacteria. Gamma show up in general a lot in the top 20 hits.

What kind of enzymes are present? Beta-1,4-endoglucanase. Found several cellulase enzymes present in the garden that are of fungal origin so maybe the genes are only being expressed in the garden/dump.

Video of 10,000s of worker ants dumping the plant material dropping material into these huge dumps. The mounds have stratification as material is dumped at the top and ages and decomposes. Cellulose content at the top and bottom of dump is correlated with age, so the bottom has least amount of cellulose.

Diversity of leaf cutting ants – 210 lineages of fungus growing ant. Most are not leaf cutters. So there are different microbial associations with the different groups that should be determined.

Insect-fungal mutualisms are not unique to ants. Fungus-growing termites. May have cellulosic capabilities. Beetles and yeasts, where the beetles spread the yeast (these I presume would be Ceratocystis and Ophiostoma).

How much of the leaf material brings in the microbial community. The ants groom the leaves to remove contaminants (like spores) which directs the community composition. I wonder how many plant endophytic fungi might still come in?

Bacteria in the farm may actually induce the fungal production of cellulosic enzymes. 10k 18S sequences from different strata.