Kaçar Lab at UW-Madison

Looking for suggestions for concentrating multiple low concentration, replicate 50 uL DNA and RNA extractions ranging from 0-3 ng/uL. Column or mag bead preference? Or SpeedVac? TIA!! Please share.

We show that losing the N-term slows growth under temp/pH stress, while adding archaeal C-term tails boosts fitness at high temp + anaerobiosis.

Take home: Evolution of a conserved IF2 core with stress-tuning evolutionary add-ons.

Study led by Evrim Fer @uwmadisonmdtp.bsky.social! #translation

Latest work! 🧬

We uncover how evolution of translation initiation factor 2 (IF2) extensions links translation to bacterial stress response. We map 7 structural architectures & show how terminal extensions are enriched in intrinsic disorder & phase-separation features.

Link: doi.org/10.64898/202...

The World’s Top Universities of 2026 Explore the top universities of 2026 leading in innovation, academic performance, and global engagement.

@uwmadison.bsky.social is the #2 public university in the US!

time.com/7358185/top-...

GitHub - ploomber/ploomber: The fastest ⚡️ way to build data pipelines. Develop iteratively, deploy anywhere. ☁️ The fastest ⚡️ way to build data pipelines. Develop iteratively, deploy anywhere. ☁️ - ploomber/ploomber

Does anybody know what happened with Ploomber? Why is the repo archived? Should I keep building ploomber pipelines? #datascience #python #jupyter
github.com/ploomber/plo...

Ecological constraints and evolutionary trade-offs shape nitrogen fixation across habitats Abstract. From its earliest beginnings, life’s expansion into new habitats has been profoundly shaped by its reciprocal interactions with Earth’s changing

New paper! Why are some Nitrogen fixing microbes more complex?

@msobol.bsky.social et al. find that microbes with more N2-fixation genes have larger, more versatile genomes, showing how changing environments shaped this key metabolism!

> academic.oup.com/ismecommun/a... @isme-microbes.bsky.social

Ecological constraints and evolutionary trade-offs shape nitrogen fixation across habitats Abstract. From its earliest beginnings, life’s expansion into new habitats has been profoundly shaped by its reciprocal interactions with a changing Earth.

Ecological constraints and evolutionary trade-offs shape nitrogen fixation across habitats academic.oup.com/ismecommun/a... #jcampubs

We show that losing the N-term slows growth under temp/pH stress, while adding archaeal C-term tails boosts fitness at high temp + anaerobiosis.

Take home: Evolution of a conserved IF2 core with stress-tuning evolutionary add-ons.

Study led by Evrim Fer @uwmadisonmdtp.bsky.social! #translation

Latest work! 🧬

We uncover how evolution of translation initiation factor 2 (IF2) extensions links translation to bacterial stress response. We map 7 structural architectures & show how terminal extensions are enriched in intrinsic disorder & phase-separation features.

Link: doi.org/10.64898/202...

Thank you!

Fabulous work! 👏

Me pregunto qué pensaría Susumu Ohno de que los eventos más antiguos que podemos rastrear mediante métodos filogenéticos sean procesos de duplicación génica.

a daring approach: looking at LUCA's ancestors, i.e. pre-darwinian evolution. but not surprising it's coming from @kacarlab.bsky.social 👏
glad to see Iwabe et al. (1989) among the references (blew my mind when it came out >30 y ago)

Universal paralogs provide a window into evolution before the last universal common ancestor Universal paralog protein families form due to gene duplications that occurred prior to the last universal common ancestor of life. This perspective describes how these protein families offer valuable...

What happened before the last universal common ancestor? Pre-LUCA evolution is hard to study. In our new Cell Genomics Perspective we spotlight how paralogous proteins open a window onto the deepest chapters of evolution. 🧬🌍

Out today!

--> www.cell.com/cell-genomic... @cellpress.bsky.social

Bookmarking, #bookmark

Thank you!

Very nice work!!

New collaborative paper! ⚡

Hannah Feinsibler et al. show that synthetic FeS, FeNiS, and NiS compounds catalyze H+ and nitrate reduction under hydrothermal-vent–like conditions, supporting mineral precursors to enzymes like hydrogenases and nitrogenases! #astrobiology

chemrxiv.org/doi/full/10....

Ecological constraints and evolutionary trade-offs shape nitrogen fixation across habitats Abstract. From its earliest beginnings, life’s expansion into new habitats has been profoundly shaped by its reciprocal interactions with Earth’s changing

New paper! Why are some Nitrogen fixing microbes more complex?

@msobol.bsky.social et al. find that microbes with more N2-fixation genes have larger, more versatile genomes, showing how changing environments shaped this key metabolism!

> academic.oup.com/ismecommun/a... @isme-microbes.bsky.social

Universal paralogs provide a window into evolution before the last universal common ancestor Universal paralog protein families form due to gene duplications that occurred prior to the last universal common ancestor of life. This perspective describes how these protein families offer valuable...

What happened before the last universal common ancestor? Pre-LUCA evolution is hard to study. In our new Cell Genomics Perspective we spotlight how paralogous proteins open a window onto the deepest chapters of evolution. 🧬🌍

Out today!

--> www.cell.com/cell-genomic... @cellpress.bsky.social

Resurrected Nitrogenases Recapitulate Canonical N-isotope Biosignatures Over Two Billion Years - Astrobiology Nitrogen isotope fractionation (ε15N) in sedimentary rocks has provided evidence for biological nitrogen fixation, and thus primary productivity, on the early Earth.

Resurrected Nitrogenases Recapitulate Canonical N-isotope Biosignatures Over Two Billion Years
astrobiology.com/2025/11/resu... #astrobiology #genomics #evolution #biosignatures

Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years - Nature Communications The study shows that nitrogenase enzymes have maintained stable isotope signatures over billions of years, revealing how ancient microbes shaped Earth’s nitrogen cycle and offering a new experimental ...

Our new paper, out today! We resurrected ancient nitrogenases first used by life on Earth 3 billion years ago. We combined synthetic biology and geology & validated their chemical #biosignature in rocks that helps reveal ancient life on Earth!(and beyond!)

Link: www.nature.com/articles/s41...

NASA NASA.gov brings you the latest news, images and videos from America's space agency, pioneering the future in space exploration, scientific discovery and aeronautics research.

Our latest paper on ancient microbes and nitrogen is featured on the NASA website today! 🚀🔬Way to go, @hollyrucker.bsky.social!

Resurrecting Ancient Enzymes in NASA’s Search for Life Beyond Earth
www.nasa.gov

Paper link: www.nature.com/articles/s41... #astrobiology @uwmadscience.bsky.social

I wonder if some of the Archean fossils I've found were using these molecules?

Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years - Nature Communications The study shows that nitrogenase enzymes have maintained stable isotope signatures over billions of years, revealing how ancient microbes shaped Earth’s nitrogen cycle and offering a new experimental ...

Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years www.nature.com/articles/s41... #jcampubs

Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years - Nature Communications The study shows that nitrogenase enzymes have maintained stable isotope signatures over billions of years, revealing how ancient microbes shaped Earth’s nitrogen cycle and offering a new experimental ...

Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years
#nitrogen #evolution
@natcomms.nature.com
www.nature.com/articles/s41...

Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years  Nitrogen isotope fractionation (ε15N) in sedimentary rocks has provided evidence for biological nitrogen fixation, and thus primary productivity, on the early Earth. However, the extent to which molecular evolution has influenced the isotopic signatures of nitrogenase, the enzyme that catalyzes the conversion of atmospheric nitrogen (N₂) to bioavailable ammonia, remains unresolved. Here, we reconstruct and experimentally characterize a library of synthetic ancestral nitrogenase genes, spanning over 2 billion years of evolutionary history. We assess the resulting ε¹⁵N values under controlled laboratory conditions. All engineered strains exhibit ε15N values within a narrow range comparable to that of modern microbes, suggesting that molybdenum (Mo)-dependent nitrogenase has been largely invariant throughout evolutionary time since the origins of this pathway. The results of this study support the early origin of molybdenum nitrogenase and the resilience of nitrogen-isotope biosignatures in ancient rocks, while also demonstrating their potential as powerful tools in the search for life beyond Earth.

Another great paper from @kacarlab.bsky.social at @uwbact.bsky.social suggesting that the molybdenum-dependent nitrogenase has been largely invariant for a long time -> Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years

Thank you!

Resurrecting Ancient Enzymes in NASA's Search for Life Beyond Earth - NASA Science NASA-supported scientists have resurrected an enzyme first used by organisms on Earth 3.2-billion years ago and, in the process, have validated a chemical

Check out NASA’s new press release on how we recreated a molecule used by some of Earth’s earliest life forms, helping us understand how life began here and how we might spot signs of life on other planets! Big congrats to first author, @hollyrucker.bsky.social!

science.nasa.gov/science-rese...

Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years - Nature Communications The study shows that nitrogenase enzymes have maintained stable isotope signatures over billions of years, revealing how ancient microbes shaped Earth’s nitrogen cycle and offering a new experimental ...

Our new paper, out today! We resurrected ancient nitrogenases first used by life on Earth 3 billion years ago. We combined synthetic biology and geology & validated their chemical #biosignature in rocks that helps reveal ancient life on Earth!(and beyond!)

Link: www.nature.com/articles/s41...