Janna Fierst

A novel, fig-associated microbe promotes reproductive success via variable life history mechanisms in C. elegans and C. inopinata Variation in life history strategies is among the most striking features of animal diversity. Simultaneously, the microbes an animal interacts with are a critical and dynamic aspect of the host enviro...

Very excited to share this work led by Austin Link, a graduate student in our lab. We have discovered a novel, fig-associated microbe that promotes reproductive success via variable life history mechanisms in two nematode species.

www.biorxiv.org/content/10.6...

Check out our preprint investigating host use in sympatric Caenorhabditis nematodes! We found three Caenorhabditis species in a local community are associated with different invert taxa, and document a strong association between one species and invasive nitidulid beetles.
doi.org/10.64898/202...

Recent discoveries on the acquisition of the highest levels of human performance Scientists have long debated the origins of exceptional human achievements. This literature review summarizes recent evidence from multiple domains on the acquisition of world-class performance. We re...

Multidisciplinary training, over time, produces the highest impact people

www.science.org/doi/10.1126/...

Sunday run

Causal modelling of gene effects from regulators to programs to traits - Nature Approaches combining genetic association and Perturb-seq data that link genetic variants to functional programs to traits are described.

GWAS has been an incredible discovery tool for human genetics: it regularly identifies *causal* links from 1000s of SNPs to any given trait. But mechanistic interpretation is usually difficult.

Our latest work on causal models for this is out yesterday:
www.nature.com/articles/s41...
A short🧵:

An RNA splicing system that excises DNA transposons from animal mRNAs - Nature A new type of mRNA splicing mechanism discovered in Caenorhabditis elegans that detects and removes inverted repeats also occurs in human cells, thereby providing another strategy to protect against t...

www.nature.com/articles/s41...

Investigating the differential microRNAs expression in young and aged Drosophila melanogaster following Flock House Virus infection MicroRNAs (miRNAs) are small non-coding RNAs ~ 19–22 nt long that post-transcriptionally regulate their mRNA targets. In Drosophila melanogaster, the role of miRNAs has mostly been studied in regar...

Investigating the differential microRNAs expression in young and aged Drosophila melanogaster following Flock House Virus infection www.tandfonline.com/doi/full/10....

New paper! Congrats to all authors! @jannafierst.bsky.social

This surprisingly relaxing footage is from SIX MILES under the ocean – and it’s the deepest ecosystem yet discovered

Precision-edited histone tails disrupt polycistronic gene expression controls in trypanosomes - Nature Communications Transcription in trypanosomatids, such as Trypanosoma brucei, is predominantly polycistronic and involves unconventional RNA polymerase II promoters. This study uses precision gene editing, site-satur...

I used inducible CRISPR/Cas9 to make Trypanosoma brucei cell line that allowed me to edit originally muti-copy histone gene. We uncovered a novel role of H4 histone tail in gene regulation. I enjoyed working on this exciting project with @joanarcf.bsky.social, a great mentor.
doi.org/10.1038/s414...

Excited to contribute to the Mitoribosome collaborative study led by @wredenberglab.bsky.social in @natcomms.nature.com🎉 "The mitochondrial methylation potential gates mitoribosome assembly"
The assembly starts before the completion of the rRNA gene cluster processing🧵
www.nature.com/articles/s41...

A novel sex-associated genomic region in Catostomus fish species Abstract. Genomic regions that influence sex are hypothesized to play a key role in evolutionary diversification, as sex determination mechanisms may promo

Delighted to post some cool science - a collaboration with my former grad students Cassandre and Jill, and collaborator extraordinaire @erynmcfarlane.bsky.social!

doi.org/10.1093/jher...

My quote of the day

I kept a diary right after I was born. Day 1: Tired from the move. Day 2: Everyone thinks I'm an idiot.

Steven Wright

Lineage-resolved analysis of embryonic gene expression evolution in C. elegans and C. briggsae The constraints that govern the evolution of gene expression patterns across development remain unclear. Single-cell RNA sequencing can detail these constraints by systematically profiling homologous ...

Despite all that is going on, we are still all working on our science. Our 2nd collaboration with @jisaacmurray.bsky.social‬ and Bob Waterston (UW) is out:

Lineage-resolved analysis of embryonic gene expression evolution in C. elegans and C. briggsae | Science www.science.org/doi/10.1126/...

Crossover patterning through condensation and coarsening of pro-crossover factors Nature Cell Biology - Zhang et al. provide evidence that, during meiosis, recombination proteins assemble into active droplets, the coarsening of which partially explains the phenomenon of...

Very happy (and frankly relieved) to see this paper finally out in peer-reviewed form. (Preprint was posted in August 2021, but this is the world we live in now). rdcu.be/erMk6

🚨📢 New paper alert!
A study led by Kirsten Senti and Julius Brennecke offers new insights into how ancient endogenous retroviruses diversified to exploit different cell “niches” in the fruit fly ovary, and how the host’s defenses adapted in return. https://imba.science/Brennecke_EMBOJ

Towering behavior and collective dispersal in Caenorhabditis nematodes Perez et al. report that self-assembling nematode towers occur in nature and can function as collective dispersal structures. Using Caenorhabditis elegans, they establish a tractable empirical model t...

Nematode towers that you can get to grow in lab using C. elegans. Maybe a new, tractable model system for studying self-organization in the lab. 🧪

"Towering behavior and collective dispersal in Caenorhabditis nematodes"
by Perez et al. (2025, Current Biology)
www.cell.com/current-biol...

Human-like object concept representations emerge naturally in multimodal large language models - Nature Machine Intelligence Multimodal large language models are shown to develop object concept representations similar to those of humans. These representations closely align with neural activity in brain regions involved in o...

Great work by Changde Du from Huiguang He's lab at the Chinese Academy of Sciences. How similar are visual and conceptual representations in (multimodal) large language models to those found in humans? It turns out quite similar!
www.nature.com/articles/s42...

It won’t last long but for the first time since November 26 I have no outstanding grant or manuscript reviews 🥳

This is our cultural revolution and in many ways it’s already done.

1/5 We introduce Movi Color, led by Steven Tan (a brilliant undergrad member of Langmead lab) for taxonomic and multi-class classification. It uses a full-text index based on the move structure and does not rely on predefined values (like k-mer length) for index building.
github.com/mohsenzakeri...

Structural insights into light harvesting by antenna-containing rhodopsins in marine Asgard archaea - Nature Microbiology Uncultured open-ocean Asgard archaea can harvest light energy using rhodopsins and diverse hydroxylated carotenoid antennas.

OUT NOW:

Structural insights into light harvesting by antenna-containing rhodopsins in marine #Asgard #archaea

@bejalab.bsky.social @labinoue.bsky.social

#microsky 🦠🧪

www.nature.com/articles/s41...

Your regular reminder about why you should publish in @jevbio.bsky.social:

My ongoing request:

If your NSF or NIH grant was terminated--whether at Harvard or elsewhere--please report it here.

NSF: grant-watch.us/submit-nsf.h...

NIH: grant-watch.us/submit-nih.h...

Our trackers are actively used in lawsuits and are often the only record that terminations ever occurred.

AAAAHHHHHH

Simulated early Earth geochemistry fuels a hydrogen-dependent primordial metabolism - Nature Ecology & Evolution In an iron-sulfide chemical garden experiment that mimics the kind of hydrothermal vents that might have occurred in the early Archaean, mackinawite and greigite are precipitated and abiotic H2 is pro...

In this new publication, we took #archaea for a walk in the chemical garden 😉. The abiotic hydrogen produced in this setting can fuel M. jannaschii’s metabolism. Great interdisciplinary collaboration with the Orsi lab who initiated and led this study. More here www.nature.com/articles/s41...

Unraveling the tempo and mode of horizontal gene transfer in bacteria Research on horizontal gene transfer (HGT) has surged over the past two decades, revealing its critical role in accelerating evolutionary rates, facil…

www.sciencedirect.com/science/arti...

Nearly missed my bus stop reading this fascinating review :)

I’m so sorry. And so, so angry.

🙏 We need your help 🙏

The government continues to cancel grants at both NIH and NSF to censor science it doesn't like.

We're tracking terminations to organize and advocate. Please report your terminated grants:

NIH:
forms.gle/J2znQ7y7YpeP...

NSF: airtable.com/appGKlSVeXni...

w/ @noamross.net

There's been credible info of intent to delete National Science Foundation (NSF) awards from Research.gov databases during planned downtime, so I grabbed all awards from 1960 to present and uploaded them to a free and open research repository. Please share!

dataverse.harvard.edu/dataset.xhtm...

A conserved opal termination codon optimizes a temperature-dependent trade-off between protein production and processing in alphaviruses Alphaviruses optimize viral polymerase production and polyprotein processing at distinct temperatures via a premature stop codon.

Our study exploring the evolutionary mechanism of alphavirus opal codon retention is now online! www.science.org/doi/10.1126/...