Charlie Pugh
@cwjpugh.bsky.social
250 followers 1.2K following 10 posts
PhD candidate - Machine Learning and Genomics @CRG.eu with @jonnyfrazer.bsky.social and @MafaldaFigDias
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cwjpugh.bsky.social
We also made some improvements with genomic language model, Evo 2, but in this case the interpretation was less clear. See the preprint for more details. Code for using LFB will made available shortly. 10/10
cwjpugh.bsky.social
This provides evidence that better fitness estimation can be achieved at negligible computational cost by bridging the gap between likelihood and fitness at inference time. 9/n
cwjpugh.bsky.social
This trend held across DMS assay types and mutational depth, and also on prediction of clinical variants. 8/n
We show a scatterplot of ROC-AUCs for each gene, calculated separating benign and pathogenic labelled variants with either usual or LFB fitness estimation
cwjpugh.bsky.social
On ProteinGym, LFB provided significant improvements across model classes and sizes and we saw that larger better fit models provided better predictions in general.
proteingym.org 7/n
We show a plot of Model Size vs Mean Spearman Correlation across the DMS datasets from ProteinGym for ESM-2 and ProGen2 model families both with and without the LFB estimation.
cwjpugh.bsky.social
We found under an Ornstein–Uhlenbeck model of evolution that our LFB should be lower variance than the standard estimate by marginalising the effect of drift. 6/n
cwjpugh.bsky.social
We tried a simple strategy — averaging predictions over sequences under similar selective pressures to effectively reduce the impact of unwanted non-fitness related correlations — likelihood fitness bridging (LFB). 5/n
We show a schematic of the LFB estimate where by averaging over predictions for a variant applied to other related sequences, we produce an score which should be closer to the true change in fitness.
cwjpugh.bsky.social
We wondered whether we might be able to improve predictions from existing models without any further training. 4/n
cwjpugh.bsky.social
Protein language models are showing promise in variant effect prediction - but there’s emerging evidence likelihood based zero shot fitness estimation is breaking down. See this excellent summary from @pascalnotin.bsky.social: pascalnotin.substack.com/p/have-we-hi... 2/n
Have We Hit the Scaling Wall for Protein Language Models?
Beyond Scaling: What Truly Works in Protein Fitness Prediction
pascalnotin.substack.com
Reposted by Charlie Pugh
Reposted by Charlie Pugh
kevinkaichuang.bsky.social
Three BioML starter packs now!

Pack 1: go.bsky.app/2VWBcCd
Pack 2: go.bsky.app/Bw84Hmc
Pack 3: go.bsky.app/NAKYUok

DM if you want to be included (or nominate people who should be!)
Reposted by Charlie Pugh
iseultleahy.bsky.social
Thanks Charlie for opening the PhD Symposium! Many thanks to everyone involved in its organisation. #CRGPhDSymp2024