Peter Koo

Peter Koo

@pkoo562.bsky.social

AI4Science researcher. Associate Professor @CSHL. My lab advances AI for genomics and healthcare! http://koo-lab.github.io

3.2K followers1.2K following130 posts

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Which mutations rewire function of regulatory DNA? Excited to share SEAM: Systematic Explanation of Attribtuion-based Mechanisms. SEAM is an explainable AI method that dissects cis-regulatory mechanisms learned by seq2fun genomic deep learning models. Led by @EESetiz 1/N 🧵👇

Hello Bluesky! Virtual registration is open for the 90th CSHL Symposium: AI in Biology! Amazing lineup of speakers! Join live on Zoom w/ Q&A, and access recordings on demand for ~48 hrs after each talk, with archive access pending speaker approval. meetings.cshl.edu/virtualregis... #cshlsymp26

meetings.cshl.edu CSHL Virtual Meetings Registration Form Cold Spring Harbor Laboratory Meetings & Courses -- a private, non-profit institution with research programs in cancer, neuroscience, plant biology, genomics, bioinformatics.

Save the date: The premier AI x Bio meeting of 2026 will be held at CSHL on May 26-31! The program brings together 50+ invited leaders in genomics, transcriptomics, protein design, drug discovery, neuro-AI, pathology, agentic AI, and more! Abstract due: March 26 meetings.cshl.edu/meetings.asp...

meetings.cshl.edu90th Symposium: AI in BiologyCold Spring Harbor Laboratory Meetings & Courses -- a private, non-profit institution with research programs in cancer, neuroscience, plant biology, genomics, bioinformatics.

Which mutations rewire function of regulatory DNA? Excited to share SEAM: Systematic Explanation of Attribtuion-based Mechanisms. SEAM is an explainable AI method that dissects cis-regulatory mechanisms learned by seq2fun genomic deep learning models. Led by @EESetiz 1/N 🧵👇

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Which mutations rewire function of regulatory DNA? Excited to share SEAM: Systematic Explanation of Attribtuion-based Mechanisms. SEAM is an explainable AI method that dissects cis-regulatory mechanisms learned by seq2fun genomic deep learning models. Led by @EESetiz 1/N 🧵👇

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SEAM is a powerful tool that helps to: 1) explore the high evolvability landscape of regulatory sequences; 2) identifies mutations that drive mechanistic changes; and 3) dissect motif syntax and context dependencies. 11/N

Which mutations rewire function of regulatory DNA? Excited to share SEAM: Systematic Explanation of Attribtuion-based Mechanisms. SEAM is an explainable AI method that dissects cis-regulatory mechanisms learned by seq2fun genomic deep learning models. Led by @EESetiz 1/N 🧵👇

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While previous analyses focused on differences in attr maps across clusters, a surprising observation was that there were also shared patterns. We disentangled the attribution signals that are sensitive versus robust to mutagenesis – we call them foreground and background. 9/N

And we tested the backgrounds across different ChromBPNet models independently trained on DNase-seq and ATAC-seq and we observe similar backgrounds! This suggests these mutagenesis-robust patterns are important context that reflects properties of the local sequence space. 10/N

Which mutations rewire function of regulatory DNA? Excited to share SEAM: Systematic Explanation of Attribtuion-based Mechanisms. SEAM is an explainable AI method that dissects cis-regulatory mechanisms learned by seq2fun genomic deep learning models. Led by @EESetiz 1/N 🧵👇

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Applying SEAM to CLIPNET, which predicts transcriptional activity measured via PRO-cap, we find that many SNVs lead to new clusters in the PIK3R3 promoter. A few specific mutations can quantitatively tune gene expression and SEAM can find them! 7/N

This analysis flagged 2 key mutations at positions 170 & 174 that created a new CAAT box. To test necessity & sufficiency, we mutated each individually and together, then examined attr maps+ predictions - single mutations -> no change - double mutation -> CAAT box + new Inr 8/N

Which mutations rewire function of regulatory DNA? Excited to share SEAM: Systematic Explanation of Attribtuion-based Mechanisms. SEAM is an explainable AI method that dissects cis-regulatory mechanisms learned by seq2fun genomic deep learning models. Led by @EESetiz 1/N 🧵👇

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Low entropy reflects all the sequences share the same nucleotides, while high entropy reflects different mutations destroyed the motif. Sometimes, we see motif preserving signature outside the vertical bands. This represents a de novo motif that appeared within that cluster. 5/N

Now, if we plot the percent mismatch of the nucleotides with respect to WT for each cluster, you can see yellow bars that reflect all sequences in the cluster share the same single nucleotide mutation. This analysis pinpoints the exact mutation that led to the new mechanism! 6/N

Which mutations rewire function of regulatory DNA? Excited to share SEAM: Systematic Explanation of Attribtuion-based Mechanisms. SEAM is an explainable AI method that dissects cis-regulatory mechanisms learned by seq2fun genomic deep learning models. Led by @EESetiz 1/N 🧵👇

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Attr maps can sometimes be easy to interpret, and sometimes they're complex. SEAM's clustered attr maps are cleaner (think SmoothGrad) and they decompose complex mechanisms via partial random mutagenesis, which occasionally disrupts key binding sites. 3/N

If we calculate the positional entropy of the sequences within each cluster, we get a cluster summary matrix. The vertical bands highlight the locations of the motifs in WT seq and entropy levels indicate whether the motif is present or not in the attr maps in each cluster. 4/N

Which mutations rewire function of regulatory DNA? Excited to share SEAM: Systematic Explanation of Attribtuion-based Mechanisms. SEAM is an explainable AI method that dissects cis-regulatory mechanisms learned by seq2fun genomic deep learning models. Led by @EESetiz 1/N 🧵👇

SEAM is conceptually simple. Starting from a reference sequence: 1) sample in a local region of sequence space via partial random mutagenesis 2) calculate attr maps to unveil the mechanisms 3) cluster attr maps based on shared mechanisms 4) cluster-based sequence analysis 2/N

Check out a Research Highlights on our work at @naturemethods by Lin Tang! www.nature.com/articles/s41...

nature.comBenchmarking genomic language models - Nature MethodsNature Methods - Benchmarking genomic language models
Peter Koo@pkoo562.bsky.social

Our work on "Evaluating the representational power of pre-trained DNA language models for regulatory genomics" led by @AmberZqt with help from @NiraliSomia & @stevenyuyy is finally published in Genome Biology! Check it out! genomebiology.biomedcentral.com/articles/10....

Some technical delays but we are all set! First talk by Alexis Battle! @alexisbattle.bsky.social

Peter Koo@pkoo562.bsky.social

2025 Machine Learning in Computational Biology (#MLCB) meeting starts TODAY (9/10) at 9:30a (EST) at the NY Genome Center in NYC! We have a great lineup of keynotes, contributed talks, and posters today and tomorrow Schedule: mlcb.org/schedule Join for free via livestream: m.youtube.com/@mlcbconf

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Some technical delays but we are all set! First talk by Alexis Battle! @alexisbattle.bsky.social

Peter Koo@pkoo562.bsky.social

2025 Machine Learning in Computational Biology (#MLCB) meeting starts TODAY (9/10) at 9:30a (EST) at the NY Genome Center in NYC! We have a great lineup of keynotes, contributed talks, and posters today and tomorrow Schedule: mlcb.org/schedule Join for free via livestream: m.youtube.com/@mlcbconf

Next talk by Johannes Linder at Calico. Talking about expanding genomic seq2fun DNNs with RBP binding and RNA processing data to consider post-transcriptional regulation.

Next talk by Alan Murphy and Masayuki (Moon) Nagai (from my lab!) who are talking about how naive fine-tuning genomic DNNs leads to catastrophic forgetting and propose *iterative causal refinement* to improve learned associations to causal understanding of cis-regulatory biology!

*Easter egg alert* NOT in the published paper. We also benchmarked Evo 2 and while it did better than other gLMs (consistent that scale can improve gLMs), it still falls short of a basic CNN trained using one-hot sequences and far short of supervised SOTA

Peter Koo@pkoo562.bsky.social

Our work on "Evaluating the representational power of pre-trained DNA language models for regulatory genomics" led by @AmberZqt with help from @NiraliSomia & @stevenyuyy is finally published in Genome Biology! Check it out! genomebiology.biomedcentral.com/articles/10....

But, when we trained D3 (score-entropy discrete diffusion for regulatory DNA) in an unsupervised manner on the genomic sequences, probing the representations of D3 was comparable to supervised SOTA (even with a basic CNN)! (100M parameters vs 40B parameters)

Here's another unpublished result: We compared probing strategies to assess how informative the pretrained representations are—benchmarking Evo2 vs D3 on Drosophila enhancer activity measured via STARR-seq. Again, D3 outperforms Evo2 (and one-hot) across all probing methods!

gLMs provide promise in learning structure in the genome, but we need to rethink how we either tokenize the genome (and no byte pair encoding isn't the answer either) or come up with a better masking strategy for non-coding genome that is different from other regions (eg coding).

Also, my perspective is coming from gLMs applied to human genomes. I think they have a lot of potential for small compact genomes that don't have as layered regulation as higher-order eukaryotes.

It's unclear whether standard NLP-based objectives (MLM or CLM) will bring us to the promised land. Unlike proteins, which have conservation at sequence and covariation levels, non-coding genome is conserved at functional level -- lots of drift and uninformative positions!

Tokenizing nucleotides/kmers and treating each token equally is like injecting lots of random words between every word in a sentence and hope that a LLM will learn the structure of the english language.

Breaking the constant propagation of pointless gLM benchmarks in the ML field (that are disconnected from how biologists will use them) is what is giving gLMs unwarranted hype. The field must rally around useful applications of gLMs.

There are many great applications for gLMs -- I'm not just a hater. The central dogma (or whatever that is being sold) is not one of them. In terms of non-coding genome regulation (outside of splice sites) in humans, there is a huge uphill battle.

This went 3 rounds of review in another journal, but 1 reviewer was adamant that this type of benchmark might be harmful to the burgeoning gLM field, which currently only benchmarks relative performance on (nearly) useless benchmarks in the non-coding regions. It was rejected!

Our benchmark is far from complete! It shows how current gLMs struggle in zero-shot capabilities for cell-type specific regulation. Think about all the differential regulation across cell types being projected onto a single genome -- this is hard to learn w/o functional data!

This went 3 rounds of review in another journal, but 1 reviewer was adamant that this type of benchmark might be harmful to the burgeoning gLM field, which currently only benchmarks relative performance on (nearly) useless benchmarks in the non-coding regions. It was rejected!

Our benchmark is far from complete! It shows how current gLMs struggle in zero-shot capabilities for cell-type specific regulation. Think about all the differential regulation across cell types being projected onto a single genome -- this is hard to learn w/o functional data!

Peter Koo reposted

One thing that really bothers me with the new "virtual cell" terminology is that it is currently largely focused on a very narrow definition of models that can predict effects of trans perturbations (gene dosage, drugs etc) on gene expression. 1/

Peter Koo reposted

This a really exciting leap forward for genomic sequence to activity gene regulation models. It is a genuine improvement over pretty much all SOTA models spanning a wide range of regulatory, transcriptional and post-transcriptional processes. 1/

Žiga Avsec@avsecz.bsky.social

Excited to launch our AlphaGenome API goo.gle/3ZPUeFX along with the preprint goo.gle/45AkUyc describing and evaluating our latest DNA sequence model powering the API. Looking forward to seeing how scientists use it! @googledeepmind

Congrats @avsecz.bsky.social! Looking forward to exploring what it has learned! 🧬

Žiga Avsec@avsecz.bsky.social

Excited to launch our AlphaGenome API goo.gle/3ZPUeFX along with the preprint goo.gle/45AkUyc describing and evaluating our latest DNA sequence model powering the API. Looking forward to seeing how scientists use it! @googledeepmind