John McCormick
tepenthouse.bsky.social
John McCormick
@tepenthouse.bsky.social
Studying transposable elements and their role in genome evolution. Proud member of the Feschotte Lab at Cornell.
Reposted by John McCormick
1/10 Genome maintenance by telomerase is a fundamental process in nearly all eukaryotes. But where does it come from?

Today, we report the discovery of telomerase homologs in a family of antiviral RTs, revealing an unexpected evolutionary origin in bacteria.
www.biorxiv.org/content/10.1...
Antiviral reverse transcriptases reveal the evolutionary origin of telomerase
Defense-associated reverse transcriptases (DRTs) employ diverse and distinctive mechanisms of cDNA synthesis to protect bacteria against viral infection. However, much of DRT family diversity remains ...
www.biorxiv.org
October 17, 2025 at 5:22 PM
Reposted by John McCormick
Are you bravely deciding to do a postdoc in the US? And also interested in some combination of genomics, immunology, and transposons? If so, consider applying to my lab at the BioFrontiers Institute in Boulder, Colorado!

jobs.colorado.edu/jobs/JobDeta...

🧪🧬 #TESky #interferosky
July 17, 2025 at 7:36 PM
Reposted by John McCormick
Just dropped our Mobile DNA review on HERVH, an ancient retrovirus now repurposed to build and defend the early human embryo. Call it genomic up-cycling!
I felt HERVH went unnoticed this year, so we published this as a refresher; two fresh data papers - coming soon.
🔗 doi.org/10.1186/s131...
🧵1/3
July 15, 2025 at 9:15 AM
Reposted by John McCormick
I want to share our latest work on a forward simulation framework on transposable element evolution. The TE Evolution Simulation Suite, or TESS, contains three components that can simulate many scenarios of genome evolution under the impact of TEs.
June 7, 2025 at 2:50 PM
Reposted by John McCormick
Seeing transposons in action is just the pick me up I needed today!
May 29, 2025 at 12:44 PM
Reposted by John McCormick
📢The peer-reviewed version of our work on TEs driving innovation of F-box genes is out now on @molbioevol.bsky.social. 🎉

paper here:
academic.oup.com/mbe/article/...

Check my previous, but still up-to-date 🧵 to read the highlights. #TEsky #evosky #Celegans
May 12, 2025 at 3:48 PM
Reposted by John McCormick
Our May issue is live!

Yukihide Tomari et al outline repression mechanisms for transposons (which “jump” through the genome like monkeys [see cover]). Meanwhile, Sarah Signor et al dive into the evolution of one of these mechanisms: the piRNA system.

More here!
www.cell.com/trends/genet...
May 5, 2025 at 4:02 PM
Reposted by John McCormick
💥🥳 At long last, our latest paper is out!

Gag proteins of endogenous retroviruses are required for zebrafish development

www.pnas.org/doi/10.1073/...

Led heroically by Sylvia Chang & @jonowells.bsky.social

A study which has changed the way I think of #transposons! No less! 🧵 1/n
Gag proteins encoded by endogenous retroviruses are required for zebrafish development | PNAS
Transposable elements (TEs) make up the bulk of eukaryotic genomes and examples abound of TE-derived sequences repurposed for organismal function. ...
www.pnas.org
April 30, 2025 at 10:45 AM
Reposted by John McCormick
This is a very cool article. They did T2T (high depth, low error) sequencing on genomes from FOUR generations of a family. 🧵

"Human de novo mutation rates from a four-generation pedigree reference"

www.nature.com/articles/s41...
Human de novo mutation rates from a four-generation pedigree reference - Nature
Analysis of more than 95% of each diploid human genome of a four-generation, twenty-eight-member family using five complementary short-read and long-read sequencing technologies provides a truth set t...
www.nature.com
April 23, 2025 at 5:50 PM
Reposted by John McCormick
In this study, Hermant et al. describe the evolution of the retrotransposon MERVL and its cis-regulatory transcription factor binding motifs, highlighting the phyloregulatory adaptation at play during early embryogenesis.

Learn more here:
➡️ tinyurl.com/gd352270
April 22, 2025 at 8:00 PM
Reposted by John McCormick
A project five years in the making, we've now published complete "T2T" genomes for six additional ape species! It turns out that finishing (and analyzing) six genomes is slightly more work than one... doi.org/10.1038/s415...
April 9, 2025 at 9:31 PM
Reposted by John McCormick
Do you have transposon-related research cooking, with some cool results you are exciting to share? Start thinking about registering to #EMBOMobileGenome workshop! Nov 4-7 2025 in Heidelberg. One of the historical TE meetings, with a diverse and welcoming community. www.embl.org/about/info/c...
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The mobile genome: genetic and physiological impacts of transposable elements
www.embl.org
April 2, 2025 at 6:30 PM
Reposted by John McCormick
1/ Transposable elements are often called "jumping genes" because they mobilize within genomes. 🧬
But did you know they can also jump 𝘣𝘦𝘵𝘸𝘦𝘦𝘯 cells? 🤯
Our new study reveals how retrotransposons invade the germline directly from somatic cells.
www.biorxiv.org/content/10.1...
A short thread 🧵👇
March 17, 2025 at 11:56 AM
Reposted by John McCormick
I am thrilled to share our story online at @cellpress.bsky.social . Big thanks to all authors: Zhiping, Bill, @lubanlab.bsky.social, Keith & bluesky-less!

authors.elsevier.com/c/1kjdaL7PXu...

How to tame a genome invader? It takes wild koalas 🐨🐨 to learn it.
#Retrovirus #koala #piRNA

More below 👇
March 9, 2025 at 2:35 AM
Reposted by John McCormick
Mutations of short tandem repeats explain abundant trait heritability in Arabidopsis https://www.biorxiv.org/content/10.1101/2025.03.07.641981v1
March 12, 2025 at 5:33 PM
Reposted by John McCormick
Happy to share our manuscript on the in situ visualization of the copia retrotransposon in its final form today published in @cellcellpress.bsky.social www.cell.com/cell/fulltex.... What’s new?
March 5, 2025 at 4:02 PM
Reposted by John McCormick
This looks quite cool, latest paper from Frank Johannes on somatic mutations in trees:

Branching architecture limits the rate of somatic mutation accumulation in trees
doi.org/10.1101/2025...
March 5, 2025 at 4:40 PM
Reposted by John McCormick
Feels awkward but necessary to celebrate scientific progress in this imperiled time for US biomedical research.

Proud of our latest paper out today exploring the role of transposable elements in antiviral resistance to HIV 🦠

genomebiology.biomedcentral.com/articles/10....
🧵1/n
Transposable elements may enhance antiviral resistance in HIV-1 elite controllers - Genome Biology
Background Less than 0.5% of people living with HIV-1 are elite controllers (ECs)—individuals who maintain undetectable plasma viremia without antiretroviral therapy, despite having replication-compet...
genomebiology.biomedcentral.com
February 24, 2025 at 12:27 PM
Reposted by John McCormick
In this new Feature Review, Yukihide Tomari and colleagues examine repression mechanisms that silence transposons and discuss the dynamic coevolution of transposons and host defenses in animals.

Read for FREE till April 11th:

authors.elsevier.com/a/1keCScQbJF...
February 26, 2025 at 2:13 PM
Reposted by John McCormick
🥳Just published @nature.com. Over 25 years after the discovery of SPO11 as the enzyme responsible for initiating meiotic recombination, we finally succeeded in reconstituting its DNA cleavage activity.🧵
www.nature.com/articles/s41...
SPO11 dimers are sufficient to catalyse DNA double-strand breaks in vitro - Nature
A biochemical system recapitulates the hallmarks of meiotic double-strand break formation, with mouse SPO11 catalysing break formation in the absence of any partners and remaining covalently atta...
www.nature.com
February 19, 2025 at 4:52 PM
Reposted by John McCormick
One of the coolest and most novel findings I’ve seen in years. This is why I work in worms. To find things no one even really knew to look for. Like a conserved system that splices transposons out of mRNAs to prevent otherwise lethal insertions in essential genes! - www.biorxiv.org/content/10.1...
An RNA Splicing System that Excises Transposons from Animal mRNAs
All genomes harbor mobile genetic parasites called transposable elements (TEs). Here we describe a system, which we term SOS splicing, that protects C. elegans and human genes from DNA transposon-medi...
www.biorxiv.org
February 18, 2025 at 11:10 AM
Reposted by John McCormick
Antero-posterior patterning in the brittle star Amphipholis squamata and the evolution of body plans across echinoderms https://www.biorxiv.org/content/10.1101/2025.02.13.638179v1
February 17, 2025 at 11:36 AM
Reposted by John McCormick
Congrats Peiwei! 🥳
All the more awesomely fitting given Larry Sandler’s discovery of segregation distorter and meiotic drive!
We're excited to announce the 2025 Larry Sandler Award recipient, @peiwei-chen.bsky.social 🎉

This award recognizes students completing a PhD in Drosophila research. Dr. Chen will present the Larry Sandler Memorial Lecture on evolutionary innovation in genome defense at #Dros25 in March.

1/3🧵
February 17, 2025 at 9:19 PM
Reposted by John McCormick
This is batshit mad.Things that spread between bacteria by hijacking phage tails
"These subcellular entities then interact with phage tails from various species, forming chimeric particles that inject DNA into different bacterial species depending on the tail present"
www.biorxiv.org/content/10.1...
www.biorxiv.org
February 12, 2025 at 4:24 PM