Sign in

Chris Saunders

@ctsa.bsky.social
2K followers 689 following 19 posts

Rare disease and cancer analysis models for sequencing data. Art school survivor. Views my own.

PostsRepliesMedia
Reposted by Chris Saunders
Matt Holt @holtjma.bsky.social · 27/08/2026
Our article introducing Aardvark for variant benchmarking is now published in Genome Biology! “Aardvark: sifting through differences in a mound of variants” DOI: doi.org/10.1186/s130... GitHub: github.com/PacificBiosc... Follow along for some highlights… 1/N
doi.org
Client Challenge
12210
Reposted by Chris Saunders
Heng Li @lh3lh3.bsky.social · 16/06/2026
Minibwa is a hybrid of bwa-mem and minimap2 and the successor of bwa-mem for short-read mapping. ~4X/2.5X as fast as bwa-mem/bwa-mem2 for WGS reads at comparable accuracy. Native support of directional bisulfite-seq. Applicable to long reads. Preprint at arxiv.org/abs/2606.15357
1193109
Chris Saunders @ctsa.bsky.social · 20/02/2026
What if you could improve small variant accuracy, CNV inference, and interpretability of your HiFi WGS data by taking a different approach to read mapping? Our new preprint describes portello, a method which demonstrates the potential for such improvements. (1/5)
Comparison of read mappings at HG002 chr4:40,294,825-40,295,700, showing conventional (pbmm2) read mappings (above) and portello mappings (below). The same set of unaligned input reads were input into each mapping process.
12511
Reposted by Chris Saunders
PacBio @pacbio.bsky.social · 12/01/2026
Dan Portik from #PacBio presents work on strand-specific 5hmC methylated base detection using PacBio HiFi sequencing, highlighting approaches for accurate epigenetic analysis with long reads. See it today at #PAG33 — Poster P051, 3:00–4:30 PM.
072
Reposted by Chris Saunders
Mitchell R. Vollger @mrvollger.bsky.social · 12/01/2026
I am hiring a staff bioinformatician for my new lab at the University of Utah! Please consider applying if you are on the hunt: employment.utah.edu/salt-lake-ci...
employment.utah.edu
Jobs | University of Utah
Founded in 1850, The University of Utah is the flagship institution of higher learning in Utah, and offers over 100 undergraduate and more than 90 graduate degree programs to over 30,000 students. Uni...
13032
Reposted by Chris Saunders
Glennis Logsdon @glennislogsdon.bsky.social · 16/12/2025
Absolutely thrilled to share the latest work from my lab focused on the variation and evolution of human centromeres among global populations! We assembled 2,110 human centromeres, identifying 226 new major haplotypes and 1,870 α-satellite HOR variants. www.biorxiv.org/content/10.6...
410846
Reposted by Chris Saunders
Olga Anczukow @olgaanczukow.bsky.social · 14/11/2025
Join us at this exciting Workshop on #LongReads with keynotes from @aphillippy.bsky.social @mydennis.bsky.social co-organized by @christinebeck.bsky.social and Mark Adams @jacksonlab.bsky.social Register www.jax.org/longread #RNA #genomics #bioinformatics #cancer #medicine #evolution #neuroscience
jax.org
Long-Read Sequencing Workshop
The program will involve sessions on Genome Evolution, Genome Regulation, Transcriptomics, Rare Diseases, Common Diseases, and Viral and Microbial Genomes. Committed speakers include Adam Phillipy (NH...
1269
Reposted by Chris Saunders
Jon Belyeu @jonbelyeu.bsky.social · 15/10/2025
My new tool Paraviewer is now available for use at github.com/PacificBiosc...! If you use Paraphase, try this new next-step tool - it automates and greatly simplifies variant visualization from Paraphase variant calling. If you're at #ASHG2025, visit me today at poster 4109W. #pacbio
github.com
GitHub - PacificBiosciences/Paraviewer
Contribute to PacificBiosciences/Paraviewer development by creating an account on GitHub.
175
Reposted by Chris Saunders
Jon Belyeu @jonbelyeu.bsky.social · 09/10/2025
My complex variant visualization tool SVTopo is now officially published in BMC Genomics! link.springer.com/article/10.1.... This tool allows HiFi users to view complex germline structural variation in intuitive and informative plots.
link.springer.com
Complex structural variant visualization with SVTopo - BMC Genomics
Background Structural variants are genomic variants that impact at least 50 nucleotides. Structural variants can play major roles in diversity and human health. Many structural variants are difficult to interpret and understand with existing visualization tools, especially when comprised of inverted sequences or multiple breakend pairs. Results We present SVTopo, a tool to visualize germline structural variants with supporting evidence from high-accuracy long reads in easily understood figures. We include examples of 101 visually complex structural variants from seven unrelated human genomes, manually assigned to ten categories. These demonstrate a broad spectrum of rearrangement and showcase the frequency of complex structural variants in human genomes. Conclusions SVTopo shows breakpoint evidence in ways that aid reasoning about the impact of multi-breakpoint rearrangements. The images created aid human reasoning about the result of structural variation on gene and regulatory regions.
267
Reposted by Chris Saunders
Dan Portik @dportik.bsky.social · 01/10/2025
New pre-print from the Banfield lab, highlighting an interesting case of 1.5Mb megaplasmids found in human gut. Plasmid genomes were resolved using #PacBio HiFi sequencing with hifiasm-meta for #metagenome assembly. Host association was detected using epigenetic signals. doi.org/10.1101/2025...
doi.org
Megaplasmids associate with Escherichia coli and other Enterobacteriaceae
Humans and animals are ubiquitously colonized by Enterobacteriaceae , a bacterial family that contains both commensals and clinically significant pathogens. Here, we report Enterobacteriaceae megaplas...
14822
Reposted by Chris Saunders
Matt Holt @holtjma.bsky.social · 06/10/2025
I'm excited to share our pre-print about a new variant benchmarking tool we've been working on for the past few months! Aardvark: Sifting through differences in a mound of variants GitHub: github.com/PacificBiosc... Some highlights in this thread: 1/N
github.com
GitHub - PacificBiosciences/aardvark: A tool for sniffing out the differences in vari-Ants
A tool for sniffing out the differences in vari-Ants - PacificBiosciences/aardvark
13217
Chris Saunders @ctsa.bsky.social · 05/10/2025
In Stockholm for work and got a great recommendation to Klättercentret Telefonplan for a boulder break last night. Great gym all around and easy hop on the metro from city center.
000
Reposted by Chris Saunders
Adam Phillippy @aphillippy.bsky.social · 17/06/2025
Congrats to @dantipov.bsky.social et al. on the publication of Verkko2! The team put a ton of work into this making it the first assembler that deals with the complexity of human acrocentric chromosomes. Lots of interesting discoveries to come! genome.cshlp.org/content/earl...
13219
Reposted by Chris Saunders
Ben Langmead @benlangmead.bsky.social · 17/06/2025
Now published! Note that since Vikram's original post (quoted here), he's made it easy to dynamically update a set of multi-MUMs (e.g. when more genomes are added to a pangenome) and to find multi-MUMs for huge collections like HPRCv2 genomebiology.biomedcentral.com/articles/10....
genomebiology.biomedcentral.com
Mumemto: efficient maximal matching across pangenomes - Genome Biology
Aligning genomes into common coordinates is central to pangenome construction, though computationally expensive. Multi-sequence maximal unique matches (multi-MUMs) help to frame and solve the multiple...
15423
Reposted by Chris Saunders
Mitchell R. Vollger @mrvollger.bsky.social · 05/06/2025
Very excited to share I’ll be starting my own group at University of Utah in the Department of Human Genetics in the new year! Reach out if you are interested! vollgerlab.com
96613
Reposted by Chris Saunders
Dan Portik @dportik.bsky.social · 22/05/2025
Great keynote talk at #SFAF by Rob Knight, summarizing key innovations in microbiome research over the past decade. One recent highlight is how long reads have transformed metagenome assembly, particularly #PacBio HiFi reads. The future is complete MAGs!
1103
Chris Saunders @ctsa.bsky.social · 20/05/2025
Just released a major update to the sawfish SV caller, which adds CNV calling and integration. Assessment on a set of pathogenic CNVs from Gross et al. shows this integrated-call strategy can substantially improve (single-method) recall, especially at lower HiFi sequencing depths
161
Reposted by Chris Saunders
inversion.bsky.social @inversion.bsky.social · 23/04/2025
Long-read sequencing of large pedigrees is an ideal way to map all classes of denovo mutations! A collaboration between University of Utah, University of Washington, and PacBio. Glad to be a part of this project 👏 www.nature.com/articles/s41...
nature.com
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...
1179
Reposted by Chris Saunders
Jon Belyeu @jonbelyeu.bsky.social · 22/04/2025
This example is hard to understand from e.g. IGV/Ribbon (see Fig1) but pretty simple in SVTopo: 4 blocks deleted (B,D,F,H), 2 inverted (E,G), 1 re-ordered (C)
121
Reposted by Chris Saunders
Jon Belyeu @jonbelyeu.bsky.social · 22/04/2025
I just released a new preprint! The manuscript describes SVTopo, a software tool that enhances visualization of complex SVs using HiFi data: www.biorxiv.org/content/10.1.... Here’s a summary of the results:
biorxiv.org
Complex structural variant visualization with SVTopo
Structural variants are genomic variants that impact at least 50 nucleotides and can play major roles in diversity and human health. Many structural variants are complex multi-breakpoint rearrangement...
1138
Reposted by Chris Saunders
Francisco De La Vega @ribozyme.bsky.social · 17/04/2025
Last day to submit abstracts to #HiTSeq25 @hitseq.bsky.social #ISMB2025 - send us your work for an opportunity to present in the podium or poster.
012
Reposted by Chris Saunders
Stephen Turner @stephenturner.us · 11/04/2025
Sawfish: Improving long-read structural variant discovery and genotyping with local haplotype modeling academic.oup.com/bioinformati... 🧬🖥️🧪 github.com/PacificBiosc...
1146
Reposted by Chris Saunders
Shujun Ou @sigmafacto.bsky.social · 10/04/2025
Hello bluesky world! Newbee here! I have a postdoc position immediately available in my lab. It will focus on identifying high-quality transposons in many genomes and finding their impacts in evolution and traits. Most works, including EDTA2 development and annotation of 400+ genomes, are done! 1/n
32422
Reposted by Chris Saunders
acenglish.bsky.social @acenglish.bsky.social · 10/01/2025
🚀 Truvari v5.0 is here! 🎉 What’s new? 🔹 Enhanced symbolic variant support for <DEL>, <DUP>, <INV> 🔹 Robust BND comparison for cross-representation SV matching 🔹 Improved SV sequence similarity & HUGE SV support 🔹 Cleaner UI & Revamped API 👉 More: github.com/ACEnglish/tr... #Genomics #Bioinformatics
github.com
GitHub - ACEnglish/truvari: Structural variant toolkit for VCFs
Structural variant toolkit for VCFs. Contribute to ACEnglish/truvari development by creating an account on GitHub.
065
Chris Saunders @ctsa.bsky.social · 10/04/2025
Great to see that sawfish, our new HiFi SV caller, is accepted for publication in Bioinformatics! Sawfish emphasizes local haplotype modeling to improve SV representation and genotyping in both single and joint-sample analysis. Advance-access article now available: (1/n) doi.org/10.1093/bioi...
doi.org
Sawfish: Improving long-read structural variant discovery and genotyping with local haplotype modeling
AbstractMotivation. Structural variants (SVs) play an important role in evolutionary and functional genomics but are challenging to characterize. High-accu
24324
Reposted by Chris Saunders
Jeff Carroll, PhD @jcarroll42.bsky.social · 20/03/2025
Very excited to see this study out in the world. We made what is (we think?) the first fully-humanized mouse model of a repeat expansion disorder, DRPLA, by replacing an entire copy of muring Atn1 with human ATN1 with 112 pure CAG repeats... www.biorxiv.org/content/10.1...
1134
Reposted by Chris Saunders
Matt Holt @holtjma.bsky.social · 20/03/2025
Xiao Chen #ACMGMtg25 describing Kivvi tool for assembling long repeat units in medically relevant genes (KIV2 and D4Z4) using #PacBio HiFi reads. Large repeats accurately assembled!
032
Reposted by Chris Saunders
erichjarvis.bsky.social @erichjarvis.bsky.social · 18/02/2025
My very first post on Bluesky Happy to be here. Check out our collaborative study with Bob Darnell @darnelr.bsky.social, where mice humanized for a NOVA1 gene variant unique to humans, produce more varied and complex vocalizations: www.science.org/content/arti... www.nature.com/articles/s41...
science.org
‘Eloquent’ mice point to protein that may have shaped human speech
Mice modified to have “human” version of a protein made more complex squeaks
182
Reposted by Chris Saunders
Graham McVicker @grahammcvicker.bsky.social · 11/02/2025
Excited to announce our preprint describing SUPERB-SEQ 🦸, a new method to measure Cas9 edits and their effects on gene expression in single cells. Led by @micklorenzini.bsky.social and @bradbalderson.bsky.social www.biorxiv.org/content/10.1...
biorxiv.org
Joint single-cell profiling of CRISPR-Cas9 edits and transcriptomes reveals widespread off-target events and their effects on gene expression
A longstanding barrier in genome engineering with CRISPR-Cas9 has been the inability to measure Cas9 edit outcomes and their functional effects at single-cell resolution. Here we present Superb-seq , ...
194
Reposted by Chris Saunders
Jacob Schreiber @jmschreiber91.bsky.social · 15/01/2025
EXTREMELY cool and demonstrates clearly the promise of deep learning + bio. www.nature.com/articles/s41...
nature.com
De novo designed proteins neutralize lethal snake venom toxins - Nature
Deep learning methods have been used to design proteins that can neutralize the effects of three-finger toxins found in snake venom, which could lead to the development of safer and more accessible an...
419648
Reposted by Chris Saunders
Matt Holt @holtjma.bsky.social · 11/12/2024
“StarPhase: Comprehensive Phase-Aware Pharmacogenomic Diplotyper for Long-Read Sequencing Data” is now on biorxiv! In this work, we explore the use of long-read sequencing (#PacBio #HiFi) for #pharmacogenomics #PGx. 1/N Pre-print: doi.org/10.1101/2024... Repo: github.com/PacificBiosc...
github.com
GitHub - PacificBiosciences/pb-StarPhase: A phase-aware pharmacogenomic diplotyper for PacBio datasets
A phase-aware pharmacogenomic diplotyper for PacBio datasets - PacificBiosciences/pb-StarPhase
21916
Reposted by Chris Saunders
Vijay Ramani @vram142.bsky.social · 15/11/2024
The latest from our group, led by Megan Ostrowski and @martyyang.bsky.social, is now published in final form (www.cell.com/cell/fulltex...! Many thanks to our excellent peer reviewers for suggesting several experiments (including CAF-1 perturbation) to really improve the study =) #epigenetics
cell.com
The single-molecule accessibility landscape of newly replicated mammalian chromatin
By developing a long-read sequencing method to simultaneously map replication status and protein-DNA contacts in cells, Ostrowski, Yang, et al. show that newly replicated chromatin is enriched for unw...
1420775
Chris Saunders @ctsa.bsky.social · 05/11/2024
Looking forward to some great talks at #ASHG24 in Denver this week. I’ll be there through Sat, supporting a poster on current/upcoming sawfish SV caller features (github.com/PacificBiosc...), and discussing other HiFi secondary analysis solutions. DMs are open if you'd like to sync up or hear more.
github.com
GitHub - PacificBiosciences/sawfish: Structural variant discovery and genotyping from mapped PacBio HiFi data
Structural variant discovery and genotyping from mapped PacBio HiFi data - PacificBiosciences/sawfish
0100
Reposted by Chris Saunders
Dan Portik @dportik.bsky.social · 29/10/2024
The new #PacBio SPRQ chemistry for the Revio system has some big advantages for micro and #metagenomics: - Input requirements drop from 2 micrograms to 500 nanograms (per SMRT cell) - 30% increase yield per cell (~90Gb -> 120Gb) www.pacb.com/press_releas...
pacb.com
PacBio Announces SPRQ Chemistry for Revio Sequencing Systems, a Major Advance Reducing the Cost of a HiFi Human Genome to less than $500 - PacBio
New long-read sequencing chemistry reduces DNA input requirements four-fold, enables a 33% increase in data output per SMRT Cell, improves methylation calling, and expands support for multiomics Trans...
083
Reposted by Chris Saunders
Matt Holt @holtjma.bsky.social · 26/01/2024
Excited to announce that our accompanying paper on HiPhase has been published today, I'll highlight some of the additions in this thread! #PacBio #HiFi “HiPhase: Jointly phasing small, structural, and tandem repeat variants from HiFi sequencing”: doi.org/10.1093/bioi...
doi.org
143
Reposted by Chris Saunders
Matt Holt @holtjma.bsky.social · 30/10/2023
I'm pleased to announce the release of HiPhase v1.0.0!  In addition to phasing small and structural variants from #PacBio #HiFi datasets, HiPhase now also includes support for phasing short tandem repeats (#STR) at the same time!   Full release notes can be found here: github.com/PacificBiosc...
github.com
Release HiPhase v1.0.0 · PacificBiosciences/HiPhase
Changes Added support for tandem repeat calls from TRGT; minimum supported version - v0.5.0 VCF index files (.tbi) are now automatically generated by HiPhase The reference FASTA file is now a requ...
187
Reposted by Chris Saunders
Andrew Carroll @acarroll.bsky.social · 24/10/2023
Initial release of DeepSomatic, which identifies subclonal variants when given tumor and normal BAM files. Pre-trained models and case studies available for Illumina and PacBio. Development led by Kishwar Shafin which built off a framework by Pi-Chuan Chang. (github.com/google/deeps...)
github.com
GitHub - google/deepsomatic
Contribute to google/deepsomatic development by creating an account on GitHub.
23617
Reposted by Chris Saunders
Mikhail Kolmogorov @mishakolmogorov.bsky.social · 24/10/2023
Today we announce the first release of Severus: a new tool for somatic SV calling for long reads! It's designed for complex (and simple) rearrangements in cancer genomes, but also works well for germline github.com/KolmogorovLa...
23214