Manuel Mendoza

@longchrom

Nuclear pore complexes and RNA export, Chromosomes and cytokinesis @igbmc.bsky.social Strasbourg. Who took the Bomp from the Bompalompalomp? Who took the Ram from the Ramalamading-dong? 🇻🇪 🇪🇸 🇫🇷

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Manuel Mendoza@longchrom· 14d

In which we share News (and our Views) on breakthrough work from the labs of @juanmartin-serrano.bsky.social, Wes Sundquist and Adam Frost. A protective ESCRT sleeve for ultrafine DNA bridges! Fun writing with @barrallabeth.bsky.social. @natsmb.nature.com doi.org/10.1038/s415...

During cytokinesis, unresolved UFBs can become enclosed within a nuclear-envelope-derived membrane sleeve that contains LEM2 and other inner nuclear membrane proteins. The authors11 propose that CHMP1B- and IST1-containing ESCRT-III polymers assemble within this membrane compartment, surrounding the DNA bridge and forming a coaxial structure, with the DNA occupying the core, the ESCRT assembly forming an intermediate sleeve, and the nuclear-envelope-derived membrane constituting the outer layer. This DNA-associated ESCRT pool is distinct from the canonical CEP55-dependent ESCRT-III machinery at the midbody, which normally mediates plasma membrane scission during abscission. Aurora B-dependent NoCut signaling may coordinate the activities of these two ESCRT assemblies, delaying abscission while protecting UFBs from breakage or inappropriate immune recognition. Whether the Aurora B-dependent NoCut checkpoint, which inhibits the midbody ESCRT-III pool, also regulates the DNA-associated ESCRT-III assembly remains unclear (dashed arrow).

Manuel Mendoza@longchrom· 24d

This whole story is crazy, but the definition of terrorism in the US is particularly absurd podcasts.apple.com/fr/podcast/t...

Partial transcript of a “This American Life” episode about the federal trial of anti-ICE protesters accused of providing material support to terrorism. Despite widespread attention on whether the defendants were “Antifa” or whether Antifa is a terrorist organization, those were not the legal questions the jury had to answer. Instead, the jury was asked whether the defendants provided material support to terrorists, which amazingly applies if they intentionally caused more than $1,000 in damage to federal property. The prosecution argued that graffiti, slashed tires, and a damaged security camera met that standard.

Manuel Mendoza@longchrom· Jun 22

This article in Le Monde about French research in general and the CNRS in particular has a few depressing graphs www.lemonde.fr/sciences/art...

The graph highlights a growing divergence between Germany and France:

* In the mid-1990s, France and Germany spent similar shares of GDP on R&D.
* Germany subsequently increased its R&D investment by about 1 percentage point of GDP.
* France’s R&D effort remained largely stagnant.
* By 2023, Germany spends 3.15% of GDP on R&D compared with 2.18% in France, a gap of nearly 1 percentage point of GDP.
* France is also well below the OECD average (2.93%).

The figure therefore illustrates that France has fallen behind both Germany and the OECD average in R&D intensity over the past three decades.

Sources listed on the graphic: OECD database, UNESCO, ANR, ERC; infographic by Le Monde.

Manuel Mendoza@longchrom· May 8

Is it @theonion.com or is it @nytimes.com ?

Screenshot of news headline: “president Trump said a cease-fire with Iran was still intact after both sides exchanged fire”.

Manuel Mendoza@longchrom· Mar 25

I never had the luck to meet her. She sounds like my type of colleague

Manuel Mendoza@longchrom· Mar 25

Front page of the French newspaper Le Monde. The main headline reads: “Le PS se divise sur sa stratégie pour 2027” (“The Socialist Party is divided over its strategy for 2027”). Smaller subheadings mention internal disagreements, criticism from party figures, and strategy debates following electoral (mixed to positive) results.

Manuel Mendoza@longchrom· Feb 15

Good prose is food for the soul

From “The Narrow Road to the Deep North” by Richard Flanagan

Manuel Mendoza@longchrom· Jan 4

Party like it’s the 1970s

Black-and-white drawing from Argentinian artist Quino of a wooden, tank-like Statue of Liberty depicted as a Trojan horse. Soldiers in helmets climb a ladder into a hidden hatch at the statue’s base.

Manuel Mendoza@longchrom· Oct 9

That's a brilliant story, reminds me of this

Quote by Richard Feynman (from "What Do You Care What Other People Think?")

Manuel Mendoza@longchrom· Sep 22

Some studies suggest that the Earth is flat, but many experts are skeptical

Screen capture of BBC headline:
Trump will reportedly link autism to pain reliever Tylenol - but many experts are sceptical
Some studies have suggested an association between the two, but experts say there is no causal relationship.

Manuel Mendoza@longchrom· Jun 24

War is Peace. Freedom is Slavery. Ignorance is Strength.

New York Times front page: Iran announces ceasefire; Israel says attacks continue; Trump’s ceasefire announcement caught own top officials by surprise

Manuel Mendoza@longchrom· Jun 7

david lynch once said “get me six singing black dancers, an Eurasian with a monkey on her shoulder, nastassja kinski, a lumberjack, and a beautiful one-legged girl” and someone actually delivered. at least once in a lifetime may we all have LYNCH SUMMONING POWER

From “Room to Dream” by David Lynch and Kristine McKenna, on the making of INLAND EMPIRE: "Part of my job was to make sure David could smoke at any location where we were shooting," said Alter.
"I had to find some unusual things, too, of course. One day he said, 'Jer-emy, get a piece of paper and a pen and write this down. I need six black dancers, including one that can sing, a blond Eurasian with a monkey on her shoulder, a lumberjack sawing wood, Nastassja Kinski, a tattooed person, [meditation instructor] Penny Bell, Dominic who's an ex-French Foreign Legionnaire, Laura Harring in her Mulholland Drive outfit, and a beautiful one-legged girl." Alter got it all.

Manuel Mendoza@longchrom· Mar 19

Almost 17 years after opening our yeast cell division lab, our first transcription paper in mouse embryonic stem cells! www.science.org/doi/10.1126/...

This schematic illustrates the interplay between transcription coactivator perturbations (e.g., TIP60 or ATAC complex depletion) and RNA homeostasis. Perturbations lead to alterations in mRNA synthesis, which are counterbalanced by changes in mRNA export and cytoplasmic decay of specific transcripts, thereby maintaining RNA homeostasis.

Manuel Mendoza@longchrom· Feb 28

We're hiring! The Development & Stem Cells department at @igbmc.bsky.social, Strasbourg 🇫🇷 is recruiting a group leader working in cell & developmental biology. Our Integrated Structural Biology department also has an open call. More details below! + contact me for informal enquiries #sciencejobs

CALL FOR TWO GROUP LEADER POSITIONS
IGBMC 2025
The Institute of Genetics, Molecular and Cellular Biology (IGBMC), a
leading European research institute near Strasbourg, France, is seeking
two outstanding group leaders to establish independent research teams in
Development & Stem Cells & Integrated Structural Biology.

Manuel Mendoza@longchrom· Feb 16

For slow people like me who don’t know the meaning of 14 in this context; now you know 😳

The number 14 in this context likely refers to the "14 Words," a white supremacist slogan coined by David Lane, a member of the neo-Nazi terrorist group The Order.
The phrase is:
"We must secure the existence of our people and a future for white children."
This slogan is widely recognized as a key phrase among white supremacists and neo-Nazi groups. In far-right circles, references to the number 14 are
sometimes used as a coded signal for their ideology.
The concern in the post you shared seems to be that Elon Musk's tweet, which includes 14 American flag emojis, was posted at 1:14 PM (which can be read as
1:14 = 14), potentially signaling an
intentional or unintentional reference to this ideology. The discussion suggests that this could be a dog whistle-an implicit message recognized .. extremists but not immediately obvious to others.

Manuel Mendoza@longchrom· Feb 1

I wonder if ChatGPT will give this same answer one year from now

Screenshot of a ChatGPT answer to a question about the January 6 Capitol Riot: No, the rioters on January 6, 2021, were not justified in storming the U.S. Capitol. Their actions were based on the false belief that the 2020 U.S. presidential election was stolen, despite numerous court rulings, audits, and investigations confirming the legitimacy of the results.

The attack was an attempt to overturn a lawful democratic process, and it led to deaths, injuries, and damage to a fundamental institution of American democracy. Many participants faced legal consequences, and the event resulted in Donald Trump’s second impeachment.

While some rioters believed they were acting patriotically, their methods—violence, intimidation, and disruption of a constitutional process—were not legitimate or justified in a democratic society. Peaceful protest and legal challenges are the appropriate ways to contest election results, not insurrection.

Manuel Mendoza@longchrom· Jan 26

What a time to be alive

"I think the people want to be with us," Trump said when asked about the island in the press room on board the presidential plane.
"I don't really know what claim Denmark has to it, but it would be a very unfriendly act if they didn't allow that to happen because it's for the protection of the free world," he added.
"I think Greenland we'll get because it has to do with freedom of the world," Trump continued.
"It has nothing to do with the United States other than that we're the one that can provide the freedom. They can't."
Despite Trump's apparent confidence, the prime ministers of Greenland and Denmark have both previously said the island was not for sale.

“This is fine” meme: A cartoon dog sits in a room engulfed in flames, calmly sipping a cup of coffee. The dog has a neutral expression, and a speech bubble above its head reads, “This is fine.”

Manuel Mendoza@longchrom· Jan 19

David Lynch knew exactly what is so wonderful about doing scientific research.

You can say a lot of things up front, but some of those things may never happen and a whole new thing might happen instead. It's so beautiful not knowing where it's going at first, and to discover it through action and reaction. It would be great if you could work like that all the time. I don't blame people for wanting to know what's going to happen next - they're bankrolling it, and it's a huge expense. But it would be no fun if you knew everything up front. It would just be a job.

Manuel Mendoza@longchrom· Jan 16

A scene from the film Mulholland Dr. featuring a dark theater setting. A performer on stage dramatically declares ‘No hay banda!’ (There is no band!) while gesturing passionately. RIP David Lynch, magician.

Manuel Mendoza@longchrom· Dec 13

Christmas lunch with my wonderful lab. I wish I could say the hats were photoshopped in!

A group of smiling colleagues wearing festive elf hats and one Santa hat gathered around a wooden table enjoying a Christmas lunch. The table is set with plates of food, drinks, and holiday decorations, and the Santa-hat-wearing PI feels happy and utterly embarrassed.

Manuel Mendoza@longchrom· Dec 9

7/ We found that power law scaling persists into mitosis, though the scaling exponent decreases. This reflects a shift in chromatin behavior during mitotic compaction, likely linked to phase separation dynamics, that explains how the memory from interphase compaction is carried over to mitosis.

Line graph showing the time-dependent evolution of the power law exponent (ν) for chromatin compaction in Drosophila neuroblasts. Black line represents control cells, while orange line represents colcemid-treated cells (prolonged metaphase). The exponent decreases progressively from ~0.8 in early mitosis to ~0.3 in metaphase, indicating changes in chromatin organization and phase separation dynamics.

Manuel Mendoza@longchrom· Dec 9

6/ To extend this finding to mitosis, we developed a novel method to quantify chromatin volume using fluorescence intensity distributions, bypassing limitations of traditional segmentation. This allowed us to track compaction dynamics live.

Time-lapse microscopy images of a Drosophila neuroblast expressing His2Av-EGFP, showing chromatin organization relative to nuclear envelope breakdown (NEB). Frames from -20 minutes to +13 minutes around NEB illustrate progressive chromatin compaction during mitotic entry and chromosome alignment. The dashed circle outlines the nucleus (top) or the cell (bottom)

Manuel Mendoza@longchrom· Dec 9

5/ This scaling reflects molecular regulation rather than mere physical packing—when we blocked histone deacetylase activity, the precise relationship broke down.

Voronoi tessellation maps of chromatin density in Drosophila neuroblast nuclei of different sizes (25-35 µm², 15-25 µm², and 5-15 µm²) under control conditions (top row) and after treatment with Trichostatin A (TSA, bottom row). Color-coded polygons represent local chromatin density, with red indicating low density and blue indicating high density. TSA treatment disrupts chromatin organization, increasing homogeneity in density across all nuclear sizes. Scale bar: 1 µm.

Manuel Mendoza@longchrom· Dec 9

4/ To address this, we used super-resolution STORM microscopy to generate detailed spatial maps of DNA organisation in interphase nuclei. Using 3D super-resolution STORM imaging, we found that nanoscale chromatin density follows a power law relationship with nuclear volume.

Super-resolution microscopy images showing chromatin organization in Drosophila neuroblast nuclei. The top panels display DNA labeled with EdU-A647, highlighting chromatin density. The bottom panels represent Voronoi tessellation of the chromatin distribution, used to quantify local density variations. Insets zoom into detailed chromatin structures.

Manuel Mendoza@longchrom· Dec 9

2/ As cells divide during development, their size evolves while DNA content remains constant. For instance, Drosophila large neural stem cells (neuroblasts) generate smaller ganglion mother cells (GMCs). How does chromosome compaction adjust to these size changes?

Microscopy image showing Drosophila neuroblasts and their progeny at different levels of chromatin compaction. Labeled regions "a", "b", and "c" highlight cells of varying sizes, with chromatin in blue (DNA) and cell boundaries in red. This image illustrates size-dependent chromatin compaction during development.

Manuel Mendoza@longchrom· Nov 28

Christmas time is here, happiness and cheer

A lab Christmas tree made of an Erlenmeyer flask filled with blue liquid, adorned with colorful microcentrifuge tubes acting as ornaments.

Manuel Mendoza@longchrom· Nov 19

Afraid I'm the first to point out in this platform that the article is not about open access but about excessive use of jargon in scientific papers. It is funny though :)

First page of the article "The growing inaccessibility of science"

Manuel Mendoza@longchrom· Nov 16

November: last month without Mariah Carey

Manuel Mendoza@longchrom· Nov 14

This project was started almost a decade ago in my old lab in CRG Barcelona (!) by the great Nicola Brownlow, and developed over the next years in IGBMC Strasbourg by Monica Dam: she grinds it til she owns it. Thanks to all involved - and to you for reading and for feedback! / END

Manuel Mendoza@longchrom· Nov 14

6/ These findings highlight an ancient, conserved strategy across species to delay abscission in response to DNA bridges. We propose Srs2/PARI work as part of the NoCut / abscission checkpoint - as for the molecular mechanism: we have only concepts of a plan :(