https://www.channel3000.com/madison-magazine/lake-mendota-reveals-revolutionary-findings-about-bacteria-evolution/article_f3e098f0-e7f5-11ef-b071-3fc857ec60c3.html
New preprint about Asgard lipids!
New, very exciting preprint where we identify polycyclic triterpenoids lipids in archaea (Asgards) for the first time. This was a wonderful collaboration with Paula Welander’s lab.
https://www.biorxiv.org/content/10.1101/2025.02.07.637177v1
Eukaryotic membranes have polycyclic triterpenoids (mainly sterols) that are essential for a variety of cellular functions, but these have not been seen in archaea. So we searched for them in Asgard archaea, this revealed biosynthetic pathways for them.
The cyclases in this pathways are ancestral to a dipternoind, present in modern plants! Heterologous expression of them revealed they cyclize geranylgeranyl pyrophosphate to form bicyclic halimadienyl pyrophosphate. 
Only other prokaryotes that produce this compound are, Mycobacteria tuberculosis, that use it to mediate intracellular persistence in host endosomes during infection! Given that Asgard have a variety of genes for membrane trafficking we believe these have similar roles in Asgards
Two papers on a 20 year study of a Freshwater Lake out today.
After 24 years of work, I’m thrilled to announce the TYMEFLIES dataset, which comprises metagenomes from Lake Mendota (Madison, WI), collected roughly every 10 days (471 samples) for 20 years!
https://rdcu.be/d5pud
NPR story on Asgard archaea
New preprint out today – implicating ANME archaea in methane production
Today we have a fun visit from Scott Cater’s high school class from Dripping Springs
Youtube video explaining our recent study on role of Asgard in eukaryotic immune systems
New commentary of a interesting paper in mBio published today
Next Time You Beat a Virus, Thank Your Microbial Ancestors
AUGUST 21, 2024 • BY MARC AIRHART
Two of our key defenses against viruses have persisted for billions of years, arising before complex life.
New study characterizing complete Asgard archaea genomes from soils published in Nature Communications
Asgard archaea modulate potential methanogenesis substrates in wetland soil
The roles of Asgard archaea in eukaryogenesis and marine biogeochemical cycles are well studied, yet their contributions in soil ecosystems remain unknown. Of particular interest are Asgard archaeal contributions to methane cycling in wetland soils. To investigate this, we reconstructed two complete genomes for soil-associated Atabeyarchaeia, a new Asgard lineage, and a complete genome of Freyarchaeia, and predicted their metabolism in situ. Metatranscriptomics reveals expression of genes for [NiFe]-hydrogenases, pyruvate oxidation and carbon fixation via the Wood-Ljungdahl pathway. Also expressed are genes encoding enzymes for amino acid metabolism, anaerobic aldehyde oxidation, hydrogen peroxide detoxification and carbohydrate breakdown to acetate and formate. Overall, soil-associated Asgard archaea are predicted to include non-methanogenic acetogens, highlighting their potential role in carbon cycling in terrestrial environments.
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