Alexandra Weisberg
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weisbergaj.bsky.social
Alexandra Weisberg
@weisbergaj.bsky.social
Asst. Prof, Dept. of Botany and Plant Pathology at Oregon State University.
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
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
November 28, 2025 at 5:02 PM
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
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
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...
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
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...
November 27, 2025 at 9:35 AM
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
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

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November 18, 2025 at 8:41 AM
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/...
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
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.
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
Reposted by Alexandra Weisberg
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
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...
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
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...
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
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
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/...
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
Reposted by Alexandra Weisberg
If you admix barcodes in your Illumina library, use Demulticoder: An R Package for the Simultaneous Analysis of Multiplexed Metabarcodes | Phytopathology® apsjournals.apsnet.org/doi/10.1094/...
Demulticoder: An R Package for the Simultaneous Analysis of Multiplexed Metabarcodes | Phytopathology®
Metabarcoding is a widely used approach relying on short DNA sequences to identify organisms present in a community. Although established workflows exist for analysis of single metabarcodes, these are...
apsjournals.apsnet.org
October 22, 2025 at 8:43 PM
Reposted by Alexandra Weisberg
A one-of-a-kind repeated natural experiment. Population Genomic Analysis of Two Independent Clonal Invasions of the Sudden Oak Death Pathogen into One Forest | Phytopathology® apsjournals.apsnet.org/doi/10.1094/...
Population Genomic Analysis of Two Independent Clonal Invasions of the Sudden Oak Death Pathogen into One Forest | Phytopathology®
Upon introduction, clonal pathogen populations are expected to go through a genetic bottleneck followed by gradual clonal divergence. Two distinct and purely clonal lineages of the sudden oak death pa...
apsjournals.apsnet.org
October 23, 2025 at 3:22 PM
Reposted by Alexandra Weisberg
New paper with my (amazing) friend and mentor @jrpenades.bsky.social
Really looking forward to see what plasmid aficionados think of this one!!
With @asantoslopez.bsky.social @wfigueroac3.bsky.social Akshay Sabins and others
www.cell.com/cell-reports...
Non-conjugative plasmids limit their mobility to persist in nature
Sabnis et al. explain why non-conjugative plasmids move at a low rate in nature. While increased mobility can easily evolve by incorporating phage DNA into plasmids, this is disadvantageous because it...
www.cell.com
October 22, 2025 at 1:12 PM
Reposted by Alexandra Weisberg
Still a couple of formatting things that need fixing (this is a "pre-proof") but our genomes paper is now available online! www.sciencedirect.com/science/arti...
Really happy to see it out there, I hope people find it useful/interesting!
Completed genomes from Variovorax provide insight into genome diversification through horizontal gene transfer
Approximately 10% of all bacterial genomes sequenced thus far contain a secondary replicon. This property of bacterial populations vastly increases ge…
www.sciencedirect.com
October 22, 2025 at 3:33 PM
Reposted by Alexandra Weisberg
job alert: UC Davis is looking to hire a 9 month tenure-track Assistant Professor of Mycology in the Department of Plant Pathology. More details below, for full consideration submit by 1 December 2025

recruit.ucdavis.edu/JPF07339
Assistant Professor of Plant Pathology
University of California, Davis is hiring. Apply now!
recruit.ucdavis.edu
October 16, 2025 at 7:59 PM
Reposted by Alexandra Weisberg
This is first paper from a new line of research in my lab, with more to come soon. If interested in PDPs I highly recommend this @baym.lol paper www.nature.com/articles/s41... and this classic from Matti Jalasvuori royalsocietypublishing.org/doi/10.1098/...
Diverse and abundant phages exploit conjugative plasmids - Nature Communications
Some phages use plasmid-encoded conjugation proteins as receptors to infect their bacterial hosts, making their host range dependent on horizontal transfer of the plasmid. Here, the authors present a method for identification of new plasmid-dependent phages, and find that they are common and abundant in wastewater and their genetic diversity is largely unexplored.
www.nature.com
October 9, 2025 at 10:07 AM
Reposted by Alexandra Weisberg
UNC Chapel Hill is hiring an Assistant Professor in Plant Molecular Biology. Per Jeff
Dangl MPMI candidates are also highly desired in the search. unc.peopleadmin.com/postings/307...
Assistant Professor
The Department of Biology at UNC Chapel Hill (https://bio.unc.edu/) is searching to hire a tenure track Assistant Professor to study critical questions in Plant Molecular Biology.We seek candidates wh...
unc.peopleadmin.com
October 6, 2025 at 10:27 PM
Reposted by Alexandra Weisberg
Here’s published version of our manuscript using GWAS to investigate tailocin sensitivity in Pseudomonas syringae. TL:DR pretty clear LPS is tailocin receptor but also that P.syringae often completely swaps out its entire O antigen biosynth pathway w/ recombination

academic.oup.com/g3journal/ad...
Genomic correlates of tailocin sensitivity in Pseudomonas syringae
Abstract. Phage-derived bacteriocins, also referred to as tailocins, are structures encoded by bacterial genomes and deployed into the extracellular enviro
academic.oup.com
October 6, 2025 at 6:57 PM