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Ali Haidar

@ahaidar.bsky.social
70 followers 137 following 10 posts

mRNA Regulation and Development. Me ♡ Imaging, Condensates, Translation, RNA RNAstuff.com Postdoc in Terret/Verlhac @CIRB @CollegedeFrance

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Ali Haidar @ahaidar.bsky.social · 31/08/2026
Supinoxin treatment (DDX5 inhibitor) dissolves the Zb in 2–4 h and flattens follicle and oocyte growth in live ovarian slices over 20 h, while RK-33 (DDX3X inhibitor) does neither.
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Ali Haidar @ahaidar.bsky.social · 31/08/2026
OPP click chemistry and a fluorescent puromycin conjugate both show nascent peptides concentrating in the Zb, plus phospho-mTOR enrichment. in addition, quantitative phase imaging shows cluster-stage oocytes hold protein density constant as they grow.
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Ali Haidar @ahaidar.bsky.social · 31/08/2026
RNA-seq of mechanically isolated Zbs: 960 enriched mRNAs, encoding the very organelles inside it, and Mass spec finds 585 Zb proteins: ribosomes, and the PrLD helicases DDX3X and DDX5.
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Ali Haidar @ahaidar.bsky.social · 31/08/2026
It appears at ~65 µm oocyte diameter, in secondary to early antral follicles, and is gone by the fully grown stage. Packed with mitochondria, Golgi, ER, RNAs and RNPs, organised around an acentriolar MTOC. Nocodazole partly disassembles it; F-actin is dispensable.
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Ali Haidar @ahaidar.bsky.social · 31/08/2026
Growing mouse oocytes transiently build an organelle-and-RNA compartment next to the nucleus: The Zollo body. Unlike the Balbiani body, it looks like a site of active translation, and dissolving it stops oocyte and follicle growth.
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Robert Arkowitz @robertarkowitz.bsky.social · 30/08/2026
A transient RNP compartment boosts translation and growth of mammalian oocytes | Science Advances www.science.org/doi/10.1126/...
science.org
A transient RNP compartment boosts translation and growth of mammalian oocytes
Mammalian oocytes undergo an extended growth phase, during which transcription gradually declines. To sustain meiotic divisions and early embryonic development, growing oocytes must accumulate materna...
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Ali Haidar @ahaidar.bsky.social · 31/08/2026
Thrilled to have been a part of this amazing paper with beautiful #imaging How does the #oocyte combat cytoplasmic dilution during growth ? #Translation in the Zollo Body is one way Below are our main findings 👇
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Christopher Thomas @ovarylab.bsky.social · 31/08/2026
Excited to share this fantastic collaboration with the teams of @mhverlhac.bsky.social and @bokelab.bsky.social, where we identify and characterise the Zollo body — a transient RNP compartment that drives oocyte and follicle growth! 🥚🔬 www.science.org/doi/10.1126/...
Microscopy image of a growing oocyte enclosed within an ovarian follicle. Mitochondria are labelled in magenta, revealing the Zollo body as a distinct region next to the oocyte nucleus. Myosin II is shown in cyan, highlighting the surrounding cell structure.
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Böke Lab @bokelab.bsky.social · 12/08/2026
What does an ovary actually look like as it ages—one oocyte at a time? We mapped >85,000 oocytes in >100 intact mouse ovaries, in 3D, across the reproductive lifespan. And the ovary turned out to be much more organized than we expected. 🧵 1/5 www.nature.com/articles/s43...
nature.com
Three-dimensional mapping of intact ovaries reveals the aging dynamics of the ovarian reserve - Nature Aging
The spatiotemporal dynamics of the depletion of the ovarian reserve remain incompletely understood. Combining whole-ovary imaging, AI and modeling, the authors mapped over 85,000 mouse oocytes and fou...
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Christopher Thomas @ovarylab.bsky.social · 27/07/2026
Check out our new review in Reproduction! 💥🥚🔬 In “The explosion of life”, @anitabichisecchi.bsky.social, @petramikec.bsky.social and I explore how live imaging has shaped our understanding of ovulation, revealing the cellular and tissue dynamics that drive egg release. doi.org/10.1093/repr...
Seeing is believing: historical snapshots of ovulation. Representative stills from landmark live-imaging studies capturing periovulatory
dynamics and follicle rupture.
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bioRxiv Biophysics @biorxiv-biophys.bsky.social · 26/06/2026
Interplay Between Protein-RNA Binding and Phase Separation Drives Emergent Behavior in RNP Condensates www.biorxiv.org/content/10.64898/20…
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Molecular Cell @cp-molcell.bsky.social · 24/06/2026
Online Now: Translational activation: An unforeseen function of RNP biomolecular condensates Online now:
dlvr.it
Translational activation: An unforeseen function of RNP biomolecular condensates
In this perspective, Haidar et al. discuss the emerging function of cytoplasmic RNP condensates in translation. The perspective highlights the dual role of condensates in translational repression and activation and the biophysical properties allowing these two functions. It further proposes future directions for decoding the functional compartmentalization of condensates.
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Christophe 🔬 Leterrier @christlet.bsky.social · 24/06/2026
Getting lost in technical nitpicking was not enough to replicate what the worst human reviewers can do. Happy to announce a decisive further step: QED can now also spit nonsense on manuscript impact
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Ali Haidar @ahaidar.bsky.social · 24/06/2026
Whether condensates have real biological functions has long been debated. Our new Molecular Cell Perspective argues translation is a core one, not just repression. Next: live high-res imaging + probing condensate dynamics should let us get at where translation starts and how condensates shape it.
https://www.sciencedirect.com/science/article/pii/S1097276526003758
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Reese Richardson @reeserichardson.bsky.social · 05/06/2026
The Thermo Fisher situation keeps getting worse. We've now collected 450+ problematic images presented as verification data in TF's antibody catalog. This includes: 🖌️ Dozens more images with duplications or painting 🖨️ Hundreds of blots that all share the same background (behold slideshow below)
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Christophe 🔬 Leterrier @christlet.bsky.social · 05/06/2026
It was a pleasure to help @mariodelr.bsky.social, @henriqueslab.bsky.social and everyone on this new way to think and plan our microscopy experiments!
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Saccharomyces Genome Database @yeastgenome.bsky.social · 01/06/2026
📚 Textbook rewrite: #Yeast reveals lysosomes get protons directly from mitochondria via membrane contacts, not from cytosol as thought. Aging breaks these contacts, causing de-acidification that disrupts autophagy & cellular function 🧬 #YeastResearch 🧪 #SGD 🔬 www.yeastgenome.org/reference/S1...
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Marvin Tanenbaum @marvintanenbaum.bsky.social · 13/05/2026
For 40 years the 8-nt ‘Kozak Sequence’ was thought to mark sites of translation initiation. In a new study, we revise this model by identifying an ~80-nt sequence—the extended Translation Initiation Sequence (eTIS)— that guides ribosomes to correct start sites. 🧵 www.biorxiv.org/content/10.6...
biorxiv.org
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Gabriele Zaffagnini @gzaffagnini.bsky.social · 19/04/2026
Happy Sunday! It has been another fantastic week for our beloved #oocytes! The streak on CPLs continues with this awesome work from Miguel Leung: pubmed.ncbi.nlm.nih.gov/41986725/! Full issue here: biomed.news/bims-cebooc/... Thanks @biomednews.bsky.social for preselecting.
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Gabriele Zaffagnini @gzaffagnini.bsky.social · 12/04/2026
Happy relaxing Sunday eggficionados! Enjoy the latest papers on oocyte cell biology here: biomed.news/bims-cebooc/... The CPLs are on fire these days, here new insights on their functions: pubmed.ncbi.nlm.nih.gov/41959504/ #cebooc is powered by @biomednews.bsky.social
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Christopher Thomas @ovarylab.bsky.social · 06/01/2026
💥🥚 ANR-funded Assistant Engineer position open in our “Control & Dynamics of the Ovarian Cycle” group at IBDM Marseille 🇫🇷 Work on mouse lines + lab logistics + follicle culture/imaging 🔬 🗓️ Apply by 26 Jan: emploi.cnrs.fr/Offres/CDD/U... Please share widely — especially with colleagues in France!
Fluorescence microscopy image of an ovarian follicle (light blue/magenta), with a bright central oocyte.
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ascalaphid @ascalaphid.com · 06/01/2026
Periscelis wheeleri, the most grumpy old man fly I've ever seen
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Center for Structural Biology (CBS Montpellier) @cbsmontpellier.bsky.social · 05/11/2025
Postdoctoral position in the team of Alessandro Barducci in the CBS, focusing on multiscale simulations of RNA-driven condensates, with applications in synthetic biology. More information : www.cbs.cnrs.fr/images/jobs/... The position is expected to start in early 2026, with some flexibility.
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Karsten Rippe @karsten-rippe.bsky.social · 11/07/2025
Liquid-liquid phase separation of HP1? Not in our mouse fibroblasts… This paper by the Fabian Erdel group offers a fresh perspective on how this can be reconciled with seemingly conflicting reports: The phase separation propensity of HP1 decreases from yeast → fly → mouse. doi.org/10.1038/s414...
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Kazuhiro Maeshima @kazu-maeshima.bsky.social · 28/08/2025
Is euchromatin really “open”? Our new study @bioRxiv suggests otherwise. Using super-resolution imaging @shiori-iida.bsky.social‬ @masaashimazoe.bsky.social reveals: Euchromatin forms condensed domains in live cells. Cohesin constrains them and prevents domain mixing. www.biorxiv.org/cgi/content/...
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Kerstin Göpfrich @kgoepfrich.bsky.social · 02/09/2025
RNA droplets that grow and segregate by ribozyme catalysis. Check out our latest preprint www.biorxiv.org/content/10.1101/2025.08.29.673008v1
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Samrat Mukhopadhyay @samratmukhopadhyay.bsky.social · 20/08/2025
Happy to share our community note published in Nature Communications @natcomms.nature.com. In this 14-page article (34 authors from 9 countries), we discuss current practices in phase separation. We hope it will be useful to the biomolecular condensate community. www.nature.com/articles/s41...
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Henri Niskanen @henriniskanen.bsky.social · 04/06/2025
What controls condensate composition and function beyond binding stoichiometry? We show that condensate microenvironments play a key role, and can be probed by a micropeptide killswitch in live cells. www.nature.com/articles/s41... in @nature.com ‬ with @yaotianzhang.bsky.social Denes Hnisz & team.
nature.com
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Miha Modic @paraspeckle.bsky.social · 02/06/2025
New method drop: HCR-Proxy, a modular proximity labelling approach to profile local proteome composition around RNA at nanoscale, subcompartmental resolution. Thereby we resolved nested nucleolar layers and uncovered the grammar of spatial protein partitioning. www.biorxiv.org/content/10.1...
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Hyman Lab @hymanlab.bsky.social · 23/05/2025
We are very happy that XiaoYan's (Andy!) paper is out, congratulations to all authors @cellpress.bsky.social @xiaoyan52802927.bsky.social www.cell.com/cell/fulltex... Demixing of TDP-43 inside stress granules generates pathological aggregates linked to ALS/FTD @mpi-cbg.de @biotec-tud.bsky.social
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Milo B. Fasken, Ph.D. @milofasken.bsky.social · 19/05/2025
#mRNADecay #Ribosome #Frameshift #Scerevisiae #NMD #CodonOptimality Ribosomes modulate transcriptome abundance via generalized frameshift and out-of-frame mRNA decay: Molecular Cell www.cell.com/molecular-ce...
cell.com
Ribosomes modulate transcriptome abundance via generalized frameshift and out-of-frame mRNA decay
Zhang et al. identify a regulatory mechanism for how cells adapt to nutrient scarcity through widespread −1 ribosomal frameshifts, culminating in accelerated mRNA decay. This process, dependent on cod...
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matteomazzocca.bsky.social @matteomazzocca.bsky.social · 14/05/2025
1/ Super excited to share my first preprint from @andersshansen.bsky.social Lab! We used MINFLUX to track chromatin (H2B-Halo and Fbn2 locus) at an unprecedented 200 μs, then combined it with SPT to span μs-minutes (H2B) or SPT & Super-Res Live-Cell Imaging (SRLCI) to span μs-hours (Fbn2)
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Domenic Narducci @domenicnarducci.bsky.social · 14/05/2025
Very excited to have been a part of this great work with @matteomazzocca.bsky.social, Simon Grosse-Holz, @jessematthias.bsky.social, and @andersshansen.bsky.social. Please check it out now! www.biorxiv.org/content/10.1...
biorxiv.org
Chromatin Dynamics are Highly Subdiffusive Across Seven Orders of Magnitude
Chromatin dynamics control the timescales of essential biological processes including DNA damage repair and activation of gene promoters by distal enhancers. Prior chromatin dynamics studies have repo...
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Alexis Verger 🧬🧫🧪 @alexis-verger.cpesr.fr · 14/05/2025
Forget liquid-liquid phase separation, here comes solid phase transition 😱 www.nature.com/articles/s41...
nature.com
Solid phase transitions as a solution to the genome folding paradox - Nature
In vitro reconstitution and in vivo live-cell imaging of LHX2–EBF1–LDB1 enhancer hubs in olfactory sensory neurons reveals that these transcription factors form condensates with solid, rathe...
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Hyman Lab @hymanlab.bsky.social · 14/05/2025
Hiro's paper is out! @hiro-cg5445.bsky.social Collaboration and Tour de Force with Richard Wheeler @zephyris-science.bsky.social and many other coauthors. Big congratulations and thank you to anyone involved! www.nature.com/articles/s41...
nature.com
Small-molecule dissolution of stress granules by redox modulation benefits ALS models - Nature Chemical Biology
Uechi et al. found that a small-molecule lipoamide dissolves stress granules (SGs) by targeting SFPQ, a redox-sensitive disordered SG protein, alleviating pathological phenotypes caused by amyotrophic...
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Lerit Lab @lablerit.bsky.social · 25/04/2025
👏new paper👏 ! Our preprint is now accepted at MBoC @ascbiology.bsky.social Congrats to co-1st authors Junnan (new PI at OSU!) and Weiyi (now a Yale grad student) and 🙏 to collaborators Melissa & Jordan @myosincity.bsky.social Funded by NIH grants & NSF GRFP! www.biorxiv.org/content/10.1...
biorxiv.org
The PCM scaffold enables RNA localization to centrosomes
As microtubule-organizing centers, centrosomes direct assembly of the bipolar mitotic spindle required for chromosome segregation and genome stability. Centrosome activity requires the dynamic assembl...
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Ben Sabari @bsabari.bsky.social · 25/04/2025
I am excited to share the latest paper from my lab where we leverage the selection bias of condensate-promoting oncofusions to uncover molecular rules governing condensate specificity and function. www.cell.com/cell/fulltex....
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Randall Munroe @xkcd.com · 26/02/2025
RNA xkcd.com/3056
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Borna Novak @bornanovak.bsky.social · 15/02/2025
Excited to announce the newest member of the flock - STARLING (conSTruction of intrinsicAlly disoRdered proteins ensembles efficientLy vIa multi-dimeNsional Generative models). www.biorxiv.org/content/10.1...
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Dr Zeinab Rekad 🔬🧬🧪 @zeinabrekad.bsky.social · 14/02/2025
Not sure if anyone posted this on BSky, but here is a 'condensate' (pun intended) of the latest #RNA granules papers 'en vogue': www.cell.com/molecular-ce... #RNAsky #RNAbiology #MolCondensates
cell.com
Biomolecular condensates: It was RNA all along!
In this issue of Molecular Cell, Trussina et al. and Parker et al. present complementary lines of evidence that suggest that stress granules regulate trans RNA-RNA interactions through the action of h...
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Mir Lab @mirlab.bsky.social · 12/02/2025
1/n Excited to share our new preprint! Using live imaging in Drosophila embryos, we show that RNA Pol II clusters switch from sites of initiation to elongation during zygotic genome activation and that they are stably associated with an active gene: www.biorxiv.org/content/10.1...
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@tim_stasevich @tim-stasevich.bsky.social · 12/02/2025
Making intrabodies from antibodies just got easier! Learn how we made 𝟭𝟵 intrabodies to bind and light up peptides and histone modifications in live cells. And thanks to Academia, all sequences are freely available. (video credit: Yuko Sato @YukoSatoT2) (1/15) www.biorxiv.org/content/10.1...
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Dormann Lab @dormannlab.bsky.social · 29/01/2025
📢 The Dormann Lab is looking for a PhD student interested in the molecular mechanisms of neurodegeneration and biomolecular condensation! Interested in one of our research projects on disease-linked RNA-binding proteins, such as TDP-43 and FUS? Apply to this fantastic PhD program by February 7 👇
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Miha Modic @paraspeckle.bsky.social · 06/02/2025
I am thrilled to share the first manuscript from my group on identifying sequence and structural features promoting the condensation of RNAs that are organising highly interconnected RNA networks, thereby expanding our understanding of higher-order transcriptome assemblage. shorturl.at/pmLIj #RNASky
biorxiv.org
Integrative profiling of condensation-prone RNAs during early development
Complex RNA–protein networks play a pivotal role in the formation of many types of biomolecular condensates. How intrinsic RNA features contribute to condensate formation however remains unclear. Here...
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Ali Haidar @ahaidar.bsky.social · 07/02/2025
Protein codes promote selective subcellular compartmentalization | Science www.science.org/doi/10.1126/...
science.org
Protein codes promote selective subcellular compartmentalization
Cells have evolved mechanisms to distribute ~10 billion protein molecules to subcellular compartments where diverse proteins involved in shared functions must assemble. Here, we demonstrate that prote...
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Fitz-James Lab @fitz-james-lab.bsky.social · 05/02/2025
We are looking for a post-doc to join us in Oxford @biology.ox.ac.uk to study epigenetic inheritance! The project will use Cut&Run and RNA-seq to map and track new epimutations as they arise in Drosophila populations across multiple generations. Feel free to share! my.corehr.com/pls/uoxrecru...
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Nadine Laguette @nadinelaguette.bsky.social · 05/02/2025
Check out our most recent preprint where we describe Mecp2 as a régulatrice of cGAS-STING associated signaling. 🧪🔥
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Marvin Tanenbaum @marvintanenbaum.bsky.social · 03/02/2025
Our paper on Stopless-ORF Circular RNAs (socRNAs) is now out in Cell. By high-res tracking and comparing translation by either single or multiple ribosomes, we find that ribosomes cooperate to overcome pausing to ensure fast and efficient translation www.cell.com/cell/fulltex...
cell.com
Long-term imaging of individual ribosomes reveals ribosome cooperativity in mRNA translation
Ribosomes cooperate through transient collisions to ensure efficient translation.
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Uri Manor @manorlaboratory.bsky.social · 07/01/2025
www.nature.com/articles/s41...
nature.com
Mitochondria- and ER-associated actin are required for mitochondrial fusion - Nature Communications
The actin cytoskeleton is crucial for cell and organelle motility. Here, the authors show that actin acts upstream of the mitochondrial fusion machinery to bridge two fusing mitochondria.
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Evelina Tutucci @anilevetu.bsky.social · 06/01/2025
Phosphorylation of a nuclear condensate regulates cohesion and mRNA retention #RNAbiology #RNAlocalization www.nature.com/articles/s41...
nature.com
Phosphorylation of a nuclear condensate regulates cohesion and mRNA retention - Nature Communications
Here the authors study how interactions with nuclear speckles help localize mRNA in cells. They find that modifications of the proteins in these structures affects their cohesion and can modulate mRNA...
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