Alexandra Weisberg
@weisbergaj.bsky.social
Asst. Prof, Dept. of Botany and Plant Pathology at Oregon State University.
Reposted by Alexandra Weisberg
A long time ago in a galaxy far away, there was a SARS-CoV-2 pandemic. Our paper, led by @martibartfast.bsky.social
a) correcting errors in 4.5 million genomes & their phylogeny
b) improving representation of the Global South in public data
www.nature.com/articles/s41...
(thread 1/n)
a) correcting errors in 4.5 million genomes & their phylogeny
b) improving representation of the Global South in public data
www.nature.com/articles/s41...
(thread 1/n)
Addressing pandemic-wide systematic errors in the SARS-CoV-2 phylogeny - Nature Methods
This Resource paper presents a global SARS-CoV-2 phylogenetic tree of 4,471,579 high-quality genomes consistently constructed by Viridian, an efficient amplicon-aware assembler.
www.nature.com
February 9, 2026 at 3:16 PM
A long time ago in a galaxy far away, there was a SARS-CoV-2 pandemic. Our paper, led by @martibartfast.bsky.social
a) correcting errors in 4.5 million genomes & their phylogeny
b) improving representation of the Global South in public data
www.nature.com/articles/s41...
(thread 1/n)
a) correcting errors in 4.5 million genomes & their phylogeny
b) improving representation of the Global South in public data
www.nature.com/articles/s41...
(thread 1/n)
Reposted by Alexandra Weisberg
1/2 Want to become up to date with pangenomes and genome graphs and their history? Check out this fantastic review by @zbao.bsky.social!
Complexity welcome: Pangenome graphs for comprehensive population genomics
#pangenomes #plantscience #genomegraphs
www.cambridge.org/core/journal...
Complexity welcome: Pangenome graphs for comprehensive population genomics
#pangenomes #plantscience #genomegraphs
www.cambridge.org/core/journal...
October 27, 2025 at 5:53 PM
1/2 Want to become up to date with pangenomes and genome graphs and their history? Check out this fantastic review by @zbao.bsky.social!
Complexity welcome: Pangenome graphs for comprehensive population genomics
#pangenomes #plantscience #genomegraphs
www.cambridge.org/core/journal...
Complexity welcome: Pangenome graphs for comprehensive population genomics
#pangenomes #plantscience #genomegraphs
www.cambridge.org/core/journal...
Reposted by Alexandra Weisberg
USDA postdoctoral fellowships are open. If you’re interested in writing a postdoc fellowship with me in plant immunity, spatial defense, or vector-borne disease, please reach out.
(US citizens, nationals, permanent residents only; PhD awarded Jan 2023–Jan 2027.) www.nifa.usda.gov/grants/progr...
(US citizens, nationals, permanent residents only; PhD awarded Jan 2023–Jan 2027.) www.nifa.usda.gov/grants/progr...
AFRI Education and Workforce Development
The AFRI Education and Workforce Development Program focuses on developing the next generation of research, education, and extension professionals.
www.nifa.usda.gov
January 23, 2026 at 2:06 AM
USDA postdoctoral fellowships are open. If you’re interested in writing a postdoc fellowship with me in plant immunity, spatial defense, or vector-borne disease, please reach out.
(US citizens, nationals, permanent residents only; PhD awarded Jan 2023–Jan 2027.) www.nifa.usda.gov/grants/progr...
(US citizens, nationals, permanent residents only; PhD awarded Jan 2023–Jan 2027.) www.nifa.usda.gov/grants/progr...
Reposted by Alexandra Weisberg
www.pnas.org/doi/10.1073/...
Excited to share that PNAS published our research article focused on "Why are Ralstonia goofy?"
Excited to share that PNAS published our research article focused on "Why are Ralstonia goofy?"
January 23, 2026 at 5:43 AM
www.pnas.org/doi/10.1073/...
Excited to share that PNAS published our research article focused on "Why are Ralstonia goofy?"
Excited to share that PNAS published our research article focused on "Why are Ralstonia goofy?"
This position is still open. The Weisberg lab is recruiting a postdoc or Ph.D. student to study horizontal gene transfer in plant-associated microbial communities. Please see the job ad for more information and feel free to contact me if you have any questions!
The Weisberg Lab at Oregon State University is recruiting a postdoctoral scholar in molecular microbiology to study mobile genetic element host range and transmission in microbial communities. Please see the full job description here: files-dev.cqls.oregonstate.edu/Weisberg_Lab...
January 14, 2026 at 11:57 PM
This position is still open. The Weisberg lab is recruiting a postdoc or Ph.D. student to study horizontal gene transfer in plant-associated microbial communities. Please see the job ad for more information and feel free to contact me if you have any questions!
Reposted by Alexandra Weisberg
Lizards have evolved their own version of rock-paper-scissors. Here's my story on the genetics behind nature's games. Gift link: nyti.ms/493KGMI
January 6, 2026 at 4:21 PM
Lizards have evolved their own version of rock-paper-scissors. Here's my story on the genetics behind nature's games. Gift link: nyti.ms/493KGMI
Reposted by Alexandra Weisberg
After years of struggling with how to cryopreserve one of our endosymbiotic bacteria, we found something that worked!
🦠☃️
We crowd-sourced suggestions and then @ruthwright.bsky.social tried the most common ones (like 🥛...). Want to do the same? Here is how we did it:
www.biorxiv.org/content/10.6...
🦠☃️
We crowd-sourced suggestions and then @ruthwright.bsky.social tried the most common ones (like 🥛...). Want to do the same? Here is how we did it:
www.biorxiv.org/content/10.6...
Identifying Effective Cryoprotectant Agents for Emerging Bacterial Model Species
Host-associated bacteria live amongst eukaryotes within varied niches and form relationships ranging from facultative to obligate. With advancement in studies of such symbiotic associations, fastidiou...
www.biorxiv.org
December 8, 2025 at 3:25 PM
After years of struggling with how to cryopreserve one of our endosymbiotic bacteria, we found something that worked!
🦠☃️
We crowd-sourced suggestions and then @ruthwright.bsky.social tried the most common ones (like 🥛...). Want to do the same? Here is how we did it:
www.biorxiv.org/content/10.6...
🦠☃️
We crowd-sourced suggestions and then @ruthwright.bsky.social tried the most common ones (like 🥛...). Want to do the same? Here is how we did it:
www.biorxiv.org/content/10.6...
Reposted by Alexandra Weisberg
Thrilled to have our paper out in @science.org. Cell division guides plant cell wall formation. Does the reverse hold? We show that bimodal pectin methylesterification, via PME5 mRNA nuclear sequestration, influences plant cell division and cell plate orientation. www.science.org/doi/10.1126/...
Cell wall patterning regulates plant stem cell dynamics
The plant cell wall regulates development through spatiotemporal modulation of its chemical and mechanical properties. Pectin methylesterification is recognized as a rheological switch controlling wal...
www.science.org
December 6, 2025 at 10:11 AM
Thrilled to have our paper out in @science.org. Cell division guides plant cell wall formation. Does the reverse hold? We show that bimodal pectin methylesterification, via PME5 mRNA nuclear sequestration, influences plant cell division and cell plate orientation. www.science.org/doi/10.1126/...
Reposted by Alexandra Weisberg
"Common principles of immune receptor channels..." #ThingsThatMakeYouGoHmm 🤔 www.nature.com/articles/s41...
A wheat resistosome defines common principles of immune receptor channels - Nature
Evolutionary conservation of plant receptor structure allowed for generation of new variants of wheat and barley nucleotide-binding leucine-rich repeat receptors (NLRs) that recognize AvrSr35 of the w...
www.nature.com
December 4, 2025 at 3:40 PM
"Common principles of immune receptor channels..." #ThingsThatMakeYouGoHmm 🤔 www.nature.com/articles/s41...
Reposted by Alexandra Weisberg
We are thrilled to announce the first official release (v0.1.8) of #𝗯𝗲𝗱𝗱𝗲𝗿, the successor to one of our flagship tool, #𝗯𝗲𝗱𝘁𝗼𝗼𝗹𝘀! Based on ideas we conceived of long ago (!), this was achieved thanks to the dedication of Brent Pedersen.
1/n
1/n
Intro to Bedder – The Quinlan Lab
quinlanlab.org
December 2, 2025 at 2:28 AM
Reposted by Alexandra Weisberg
How does the arms race between #bacterial defense systems and mobile genetic elements contribute to #microbiome community structure?
Read below for an insightful exploration of this issue! It will not disappoint
@plosbiology.org 🧪
#bacteria #immune #phage #ecology
Read below for an insightful exploration of this issue! It will not disappoint
@plosbiology.org 🧪
#bacteria #immune #phage #ecology
The ecological roles of bacterial #immune systems are poorly understood. Rafael Custodio @ellinoralseth.bsky.social @brockhurstlab.bsky.social @brownlab.bsky.social & Edze Westra explore how mobile genetic elements and bacterial defenses shape #microbiome structure and function 🧪
Bacterial immune systems as causes and consequences of microbiome structure
Bacterial immune systems have evolved in response to diverse molecular "parasites", yet their ecological roles remain poorly understood. This Essay explores how interactions between mobile genetic…
plos.io
November 28, 2025 at 5:02 PM
How does the arms race between #bacterial defense systems and mobile genetic elements contribute to #microbiome community structure?
Read below for an insightful exploration of this issue! It will not disappoint
@plosbiology.org 🧪
#bacteria #immune #phage #ecology
Read below for an insightful exploration of this issue! It will not disappoint
@plosbiology.org 🧪
#bacteria #immune #phage #ecology
Reposted by Alexandra Weisberg
I taught (and co-taught) a course on human population genetics from 2000-2024. Having retired, I'm now making all the course materials public: github.com/alanrogers/p... #popgen #evbio
GitHub - alanrogers/popgen: A course on population genetics
A course on population genetics. Contribute to alanrogers/popgen development by creating an account on GitHub.
github.com
November 27, 2025 at 7:10 PM
I taught (and co-taught) a course on human population genetics from 2000-2024. Having retired, I'm now making all the course materials public: github.com/alanrogers/p... #popgen #evbio
Reposted by Alexandra Weisberg
New preprint: 🚀🧬 Starship in the genome of the lichen fungus Xanthoria. Discovery of giant transposons Starships challenged what we thought we knew about fungal genomes. But what about Starships in #lichen fungi? Let us present Tangerine! 🖥️ 🧪 🦠 🧫 #SymbioSky doi.org/10.1101/2025...
November 28, 2025 at 2:20 PM
New preprint: 🚀🧬 Starship in the genome of the lichen fungus Xanthoria. Discovery of giant transposons Starships challenged what we thought we knew about fungal genomes. But what about Starships in #lichen fungi? Let us present Tangerine! 🖥️ 🧪 🦠 🧫 #SymbioSky doi.org/10.1101/2025...
Reposted by Alexandra Weisberg
Cellular energy sensor SnRK1 suppresses salicylic acid–dependent and –independent defenses and bacterial resistance in Arabidopsis
www.pnas.org/doi/abs/10.1...
www.pnas.org/doi/abs/10.1...
Cellular energy sensor SnRK1 suppresses salicylic acid–dependent and –independent defenses and bacterial resistance in Arabidopsis | PNAS
In nature, plants cope with various pathogens that compete for cellular resources
during infection. It has long been suggested that plant defense a...
www.pnas.org
November 27, 2025 at 1:49 PM
Cellular energy sensor SnRK1 suppresses salicylic acid–dependent and –independent defenses and bacterial resistance in Arabidopsis
www.pnas.org/doi/abs/10.1...
www.pnas.org/doi/abs/10.1...
Reposted by Alexandra Weisberg
🧬🛡️How are new immune mechanisms created?
We show how Lamassu antiphage system, originated from a DNA-repair complex and evolved into a compact and modular immune machine, wt Dinshaw Patel lab in @pnas.org.
👏 @matthieu-haudiquet.bsky.social, Arpita Chakravarti & all authors!
doi.org/10.1073/pnas...
We show how Lamassu antiphage system, originated from a DNA-repair complex and evolved into a compact and modular immune machine, wt Dinshaw Patel lab in @pnas.org.
👏 @matthieu-haudiquet.bsky.social, Arpita Chakravarti & all authors!
doi.org/10.1073/pnas...
November 27, 2025 at 9:35 AM
🧬🛡️How are new immune mechanisms created?
We show how Lamassu antiphage system, originated from a DNA-repair complex and evolved into a compact and modular immune machine, wt Dinshaw Patel lab in @pnas.org.
👏 @matthieu-haudiquet.bsky.social, Arpita Chakravarti & all authors!
doi.org/10.1073/pnas...
We show how Lamassu antiphage system, originated from a DNA-repair complex and evolved into a compact and modular immune machine, wt Dinshaw Patel lab in @pnas.org.
👏 @matthieu-haudiquet.bsky.social, Arpita Chakravarti & all authors!
doi.org/10.1073/pnas...
Reposted by Alexandra Weisberg
I tried an even harder example on Gemini Pro image generation and this is quite scary/amazing. I asked for a microscopy image of around 20 HeLa cells, GFP tagged 20% nuclear, 10% membrane, +1 nuclear staining, + overlap. Image below and prompt in the following post.
November 21, 2025 at 5:32 PM
I tried an even harder example on Gemini Pro image generation and this is quite scary/amazing. I asked for a microscopy image of around 20 HeLa cells, GFP tagged 20% nuclear, 10% membrane, +1 nuclear staining, + overlap. Image below and prompt in the following post.
Reposted by Alexandra Weisberg
Our new collaborative work led by @taliamycota.bsky.social
Jiajun Cui & Emma Caullireau between my lab @ucllifesciences.bsky.social @cloeucl.bsky.social & the Karasov Lab (tkarasovlab.org) @uofubiology.bsky.social
and collaborators: @plantricia.bsky.social et al.
tinyurl.com/5yx2wmz5
(1/n)
Jiajun Cui & Emma Caullireau between my lab @ucllifesciences.bsky.social @cloeucl.bsky.social & the Karasov Lab (tkarasovlab.org) @uofubiology.bsky.social
and collaborators: @plantricia.bsky.social et al.
tinyurl.com/5yx2wmz5
(1/n)
November 18, 2025 at 8:41 AM
Our new collaborative work led by @taliamycota.bsky.social
Jiajun Cui & Emma Caullireau between my lab @ucllifesciences.bsky.social @cloeucl.bsky.social & the Karasov Lab (tkarasovlab.org) @uofubiology.bsky.social
and collaborators: @plantricia.bsky.social et al.
tinyurl.com/5yx2wmz5
(1/n)
Jiajun Cui & Emma Caullireau between my lab @ucllifesciences.bsky.social @cloeucl.bsky.social & the Karasov Lab (tkarasovlab.org) @uofubiology.bsky.social
and collaborators: @plantricia.bsky.social et al.
tinyurl.com/5yx2wmz5
(1/n)
Reposted by Alexandra Weisberg
Hot off the press! Our latest paper led by @fernpizza.bsky.social, understanding how plasmids evolve inside cells. These small, self-replicating DNA circles live inside bacteria and carry antibiotic resistance genes, but also compete with one another to replicate. 1/
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Intracellular competition shapes plasmid population dynamics
From populations of multicellular organisms to selfish genetic elements, conflicts between levels of biological organization are central to evolution. Plasmids are extrachromosomal, self-replicating g...
www.science.org
November 20, 2025 at 9:42 PM
Hot off the press! Our latest paper led by @fernpizza.bsky.social, understanding how plasmids evolve inside cells. These small, self-replicating DNA circles live inside bacteria and carry antibiotic resistance genes, but also compete with one another to replicate. 1/
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Reposted by Alexandra Weisberg
I’ve released a tool to sketch and edit phylogenetic trees!
yawak.jp/PhyloWeaver/
Load a Newick file and intuitively add/remove/resize branches.
Useful for quick conceptual trees, extracting subtrees, or turning ideas into Newick.
yawak.jp/PhyloWeaver/
Load a Newick file and intuitively add/remove/resize branches.
Useful for quick conceptual trees, extracting subtrees, or turning ideas into Newick.
PhyloWeaver – Interactive phylogenetic tree editor
Edit and visualize phylogenetic trees directly in your browser. PhyloWeaver lets you interactively rearrange tree topologies and export high-quality figures for publications and presentations.
yawak.jp
November 18, 2025 at 1:59 AM
I’ve released a tool to sketch and edit phylogenetic trees!
yawak.jp/PhyloWeaver/
Load a Newick file and intuitively add/remove/resize branches.
Useful for quick conceptual trees, extracting subtrees, or turning ideas into Newick.
yawak.jp/PhyloWeaver/
Load a Newick file and intuitively add/remove/resize branches.
Useful for quick conceptual trees, extracting subtrees, or turning ideas into Newick.
Reposted by Alexandra Weisberg
gggenomes: A Grammar of Graphics for Comparative Genomics thackl.github.io/gggenomes/ #Rstats
A Grammar of Graphics for Comparative Genomics
An extension of ggplot2 for creating complex genomic maps. It builds on the power of ggplot2 and tidyverse adding new ggplot2-style geoms & positions and dplyr-style verbs to manipulate the…
thackl.github.io
November 18, 2025 at 7:02 PM
gggenomes: A Grammar of Graphics for Comparative Genomics thackl.github.io/gggenomes/ #Rstats
Our manuscript comparing Nanopore vs. Illumina reads for population-level variant calling and genotyping is now out: journals.asm.org/doi/10.1128/... . This work was led by Andrea Schiffer and @arftrhmn.bsky.social.
A comparison of short- and long-read whole-genome sequencing for microbial pathogen epidemiology | mSystems
Genome assembly and variant calling are important steps in microbial population studies
and epidemiology. Most variant calling and genotyping pipelines are designed for Illumina
short sequencing reads...
journals.asm.org
November 13, 2025 at 9:31 PM
Our manuscript comparing Nanopore vs. Illumina reads for population-level variant calling and genotyping is now out: journals.asm.org/doi/10.1128/... . This work was led by Andrea Schiffer and @arftrhmn.bsky.social.
Reposted by Alexandra Weisberg
How do GWAS and rare variant burden tests rank gene signals?
In new work @nature.com with @hakha.bsky.social, @jkpritch.bsky.social, and our wonderful coauthors we find that the key factors are what we call Specificity, Length, and Luck!
🧬🧪🧵
www.nature.com/articles/s41...
In new work @nature.com with @hakha.bsky.social, @jkpritch.bsky.social, and our wonderful coauthors we find that the key factors are what we call Specificity, Length, and Luck!
🧬🧪🧵
www.nature.com/articles/s41...
Specificity, length and luck drive gene rankings in association studies - Nature
Genetic association tests prioritize candidate genes based on different criteria.
www.nature.com
November 7, 2025 at 12:05 AM
How do GWAS and rare variant burden tests rank gene signals?
In new work @nature.com with @hakha.bsky.social, @jkpritch.bsky.social, and our wonderful coauthors we find that the key factors are what we call Specificity, Length, and Luck!
🧬🧪🧵
www.nature.com/articles/s41...
In new work @nature.com with @hakha.bsky.social, @jkpritch.bsky.social, and our wonderful coauthors we find that the key factors are what we call Specificity, Length, and Luck!
🧬🧪🧵
www.nature.com/articles/s41...
Reposted by Alexandra Weisberg
The 5th of 6 faculty positions in UNC Biology is posted. We're working with the @ncbg.bsky.social to fill a joint position as Director of the UNC Herbarium at @ncbg.bsky.social and as Associate Professor within the Department of Biology (BIOL). Please share 1/n
unc.peopleadmin.com/postings/308...
unc.peopleadmin.com/postings/308...
Associate Professor & Director of NCBG Herbarium
This is a research, teaching, and public service position at the University of North Carolina at Chapel Hill, serving jointly as Herbarium Director at the North Carolina Botanical Garden (NCBG) and as...
unc.peopleadmin.com
November 6, 2025 at 11:36 AM
The 5th of 6 faculty positions in UNC Biology is posted. We're working with the @ncbg.bsky.social to fill a joint position as Director of the UNC Herbarium at @ncbg.bsky.social and as Associate Professor within the Department of Biology (BIOL). Please share 1/n
unc.peopleadmin.com/postings/308...
unc.peopleadmin.com/postings/308...
Reposted by Alexandra Weisberg
Widespread horizontal transfer and strong selection enhance microbial adaptation in Antarctic soils www.biorxiv.org/content/10.1... #jcampubs
November 5, 2025 at 4:25 PM
Widespread horizontal transfer and strong selection enhance microbial adaptation in Antarctic soils www.biorxiv.org/content/10.1... #jcampubs
Reposted by Alexandra Weisberg
@prczhaoyansong.bsky.social’s deep dive into the dark matter of compost communities is now out 🎉 Genomic islands hijack jumbo phages—whose capsids enable transfer of large tracts of DNA—shedding new light on the scale & scope of phage-mediated gene flow 😎
www.pnas.org/doi/10.1073/...
www.pnas.org/doi/10.1073/...
Jumbo phage–mediated transduction of genomic islands | PNAS
Bacteria acquire new genes by horizontal gene transfer, typically mediated by mobile
genetic elements (MGEs). While plasmids, bacteriophages, and c...
www.pnas.org
October 28, 2025 at 6:36 PM
@prczhaoyansong.bsky.social’s deep dive into the dark matter of compost communities is now out 🎉 Genomic islands hijack jumbo phages—whose capsids enable transfer of large tracts of DNA—shedding new light on the scale & scope of phage-mediated gene flow 😎
www.pnas.org/doi/10.1073/...
www.pnas.org/doi/10.1073/...