Matt Holt
@holtjma.bsky.social
880 followers 150 following 210 posts
Staff scientist at @PacBio; formerly @hudsonalpha; avid gamer; opinions are my own
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Reposted by Matt Holt
pacbio.bsky.social
#PacBio announces major upcoming advances for #Revio and #Vega designed to lower genome costs, expand multiomic capabilities, and support regulated research.

The SPRQ-Nx chemistry, now in beta access, delivers complete genomes for under $300 at scale.

View the press release: bit.ly/4o06eyH
Reposted by Matt Holt
jsantoyo.bsky.social
📣 PacBio Announces Major Advances for #Revio and #Vega to Lower Genome Cost and Expand Multiomic Capabilities
New SPRQ-Nx chemistry: HiFi genome for less than $300 🧪 🧬
#HiFi #LongReads #SPRQ_Nx #BetaAccess #SMRTcell #ReusableChip @pacbio.bsky.social
investor.pacificbiosciences.com/news-release...
holtjma.bsky.social
I wish the posters were up for more than a day, easy to miss a bunch

PS, I was told official tag is #ASHG25
holtjma.bsky.social
We just released a major update for StarPhase that adds support for inexact matching PGx alleles. We're hoping this streamlines the process for discovering novel allele combinations with #PacBio #HiFi data, feedback welcome!

Full notes here: github.com/PacificBiosc...

#ASHG25
Release StarPhase v1.5.0 · PacificBiosciences/pb-StarPhase
Changes Adds a new field to the output json, inexact_diplotypes. This field is intended to capture information about inexact allele matches. The behavior of this output depends on the gene: For s...
github.com
holtjma.bsky.social
I'm heading to Boston for #ASHG25 tomorrow, let me know if you'd like to chat about using HiFi sequencing for mitochondrial analyses, pharmacogenomics, or anything else!

ICYMI, also happy to discuss our new Aardvark tool for benchmarking :)
holtjma.bsky.social
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
Reposted by Matt Holt
leandrosboukas.bsky.social
Looking forward to presenting duoNovo at ASHG this week.

We use long-read sequencing to detect de novo variants without having to sequence both parents. It's conceptually straightforward, and performs very accurately among variants likely to be clinically relevant.

www.medrxiv.org/content/10.1...
Identification of de novo variants from parent-proband duos via long-read sequencing
While de novo variants cause many Mendelian disorders, their detection currently requires sequencing of the proband and both biological parents. This is not feasible when only one parent is available,...
www.medrxiv.org
Reposted by Matt Holt
kathleenclark.bsky.social
A master class from MIT in responding to authoritarian overreach:

Your “premise … is inconsistent with our core belief that scientific funding should be based on scientific merit alone.
… America’s leadership in science & innovation depends on independent thinking & open competition for excellence.
Dear Madam Secretary,
I write in response to your letter of October 1, inviting MIT to review a "Compact for Academic Excellence in Higher Education." I acknowledge the vital importance of these matters.
I appreciated the chance to meet with you earlier this year to discuss the priorities we share for American higher education.
As we discussed, the Institute's mission of service to the nation directs us to advance knowledge, educate students and bring knowledge to bear on the world's great challenges.
We do that in line with a clear set of values, with excellence above all. Some practical examples:
• MIT prides itself on rewarding merit. Students, faculty and staff succeed here based on the strength of their talent, ideas and hard work. For instance, the Institute was the first to reinstate the SAT/ACT requirement after the pandemic. And MIT has never had legacy preferences in admissions.
• MIT opens its doors to the most talented students regardless of their family's finances. Admissions are need-blind. Incoming undergraduates whose families earn less than $200,000 a year pay no tuition. Nearly 88% of our last graduating class left MIT with no debt for their education. We make a wealth of free courses and low-cost certificates available to any American with an internet connection. Of the undergraduate degrees we award, 94% are in STEM fields. And in service to the nation, we cap enrollment of international undergraduates at roughly 10%.

source: 
https://orgchart.mit.edu/letters/regarding-compact • We value free expression, as clearly described in the MIT Statement on Freedom of Expression and Academic Freedom. We must hear facts and opinions we don't like - and engage respectfully with those with whom we disagree.
These values and other MIT practices meet or exceed many standards outlined in the document you sent. We freely choose these values because they're right, and we live by them because they support our mission - work of immense value to the prosperity, competitiveness, health and security of the United States. And of course, MIT abides by the law.
The document also includes principles with which we disagree, including those that would restrict freedom of expression and our independence as an institution. And fundamentally, the premise of the document is inconsistent with our core belief that scientific funding should be based on scientific merit alone.
In our view, America's leadership in science and innovation depends on independent thinking and open competition for excellence. In that free marketplace of ideas, the people of MIT gladly compete with the very best, without preferences. Therefore, with respect, we cannot support the proposed approach to addressing the issues facing higher education.
As you know, MIT's record of service to the nation is long and enduring. Eight decades ago, MIT leaders helped invent a scientific partnership between America's research universities and the U.S. government that has delivered extraordinary benefits for the American people. We continue to believe in the power of this partnership to serve the nation.
Sincerely,
Sally Kornbluth
Reposted by Matt Holt
robert.bio
Just published an interactive article about a magical algorithm known as the Burrows-Wheeler Transform, which powers sequence alignment tools like bowtie and bwa: sandbox.bio/concepts/bwt

It's also notoriously unintuitive so I'm hoping this article helps you build that intuition.
Reposted by Matt Holt
gavinyamey.bsky.social
“A study, published on Wednesday in the New England Journal of Medicine, showed that last season’s 2024–2025 mRNA COVID vaccines reduced people’s risk of emergency department visits by 29%, their risk of hospitalizations by 39% & their risk of death by 64%”

Benefits were seen even if 0 risk factors
sorenlarsen.bsky.social
Annual COVID Vaccines Protect People against Severe Disease, Even with Prior Immunity

"The new research also “calls into question the idea that younger individuals and those without risk factors don’t need the vaccine,” Viswanathan says."
Annual COVID Vaccines Save Lives, New Study Shows
A new study shows that receiving an updated COVID vaccine reduced people’s risk of severe disease and death in all age groups, regardless of immunity from prior infection or vaccination
www.scientificamerican.com
Reposted by Matt Holt
pacbio.bsky.social
Just in: #PacBio HiFi long-read sequencing is powering the National Institute on Aging’s Long Life Family Study.

Up to 7,800 genomes and epigenomes will be sequenced on Revio systems to uncover rare variants, methylation patterns, and other factors linked to healthy aging.

🔗 bit.ly/3IUDdFo
Reposted by Matt Holt
robp.bsky.social
Have you recently completed (or finishing soon) a PhD in CS or a related discipline? Do you want to do research advancing the theory & practice of algorithmic genomics & build tools that people love to use? I'll be looking to hire a postdoc! Official ad coming soon:
docs.google.com/document/d/1...
Postdoc Description.docx
Title: Postdoctoral Associate Summary statement: The postdoctoral research associate is responsible for developing novel computational methodology for high-throughput sequence genomics tasks, as well ...
docs.google.com
Reposted by Matt Holt
jmschreiber91.bsky.social
Now that I'm settled in at @umasschan.bsky.social, I'm hiring at all levels: grad students, post-docs, and software engineers/bioinformaticians!

The goal of my lab is to understand the regulatory role of every nucleotide in our genomes and how this changes across every cell in our bodies.
Reposted by Matt Holt
robp.bsky.social
It absolutely warms my heart when I click on a pre-print that includes a bunch of top methods folks from industry and I see (1) open-source software (with a good license; MIT in this case) that is (2) written in Rust. Bravo @pacbio.bsky.social!

Moar Rust plz!

github.com/PacificBiosc...
holtjma.bsky.social
We're quite happy with how this first version of Aardvark turned out, and we are actively working on additions! If you have any suggestions, please let us know here or on GitHub!

Special thanks to all our collaborators and beta users for the initial wave of feedback!

(8/8)
holtjma.bsky.social
So in summary, Aardvark:

1. Adds a new sequence-centric "basepair" scoring scheme
2. Enables comparisons of new types of variants (TRs & SVs)
3. Includes a traditional genotype score
4. Calculates everything really fast!
5. Almost forgot, it's fully open-source!

(7/N)
holtjma.bsky.social
Even if you do not (yet) fully buy in to basepair scoring, Aardvark includes a traditional genotype score... and it calculates both sets of scoring metrics *really* fast!

For small variants, on average 16x faster than hap.py, with most runs finishing <2 minutes (16 threads).

(6/N)
holtjma.bsky.social
Since Aardvark looks at sequences, it enables some comparisons that were previously very challenging:

1. Tandem repeat (TR) v. TR benchmarking
2. TR v. small variant benchmarking
3. Structural variant (SV) benchmarking
4. Joint benchmarking (small + SV)

(5/N)
holtjma.bsky.social
With basepair scoring, we instead:

1. Mask all variants, only *sequences* are compared. Equivalent representations will receive identical scores!
2. Score each modified basepair independently, enabling implicit partial credit while removing biases from representation

(4/N)
holtjma.bsky.social
There were two driving forces behind the basepair score:

1. Equivalent variant representations can be scored inconsistently with a genotype approach
2. Traditional genotype scoring has no concept of partial credit, it's either 100% correct or 100% wrong

(3/N)
holtjma.bsky.social
The main addition in Aardvark is the "basepair" scoring scheme, which compares local haplotype *sequences* instead of variants and genotypes. See the attached figure for a quick example of how basepair scoring compares to genotype scoring.
(2/N)
holtjma.bsky.social
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