Gail R. Martin (1944–2026): Embryonic stem cell pioneer, developmental biologist, and student of Asian art and ceramics | PNAS Gail Roberta Martin, Professor Emerita of Anatomy at the University of California, San Francisco, and one of the founding figures of modern stem ce...

A very moving tribute to one of the founders of modern Stem Cell Biology: Gail Martin.
Well worth a read.

www.pnas.org/doi/10.1073/...

Apical spectrin organizes cortical actin filament bundles to pattern C. elegans cuticle ridges www.biorxiv.org/content/10.64898/2026.03...

fyi, an old favorite: "How many membrane proteins are there?" Boyd et al. Protein Science 1998, from Jon Beckwith's lab (shortly after the S. cerevisiae genome was sequenced, and shortly before the C. elegans genome was).

Would be curious if your approach reached similar conclusions!

👉 3rd aECM club Apr 14th 10 am NYC-4 pm Paris
#aECM invertebrate cuticle and molt cycle @gotworms.bsky.social
@labgrosshans.bsky.social
program sundaramlab.com/blog/aecm-cl...
👉 join our Slack forms.gle/Y6UjbnXPH1pD...

Cilia have hidden superpowers. Here, we uncover the molecular basis of one of them - cilia form specific cell attachments that alter their own signaling responses.

Given that cilia affect almost every aspect of cell biology, they are doubtless hiding many more surprises we have yet to learn!

Two rows of fluorescence images corresponding to a roughly 5 square micron field. Each row shows localization of TAX-4 in green and GCY-9 in purple in a single cilium, in either wild-type (top row) or bug-1 mutant (bottom row) animals. The cilium has two regions, called the stem and the bag, arranged like a mast and a sail. In both cases, TAX-4 is primarily in the stem and more weakly in the bag. In wild type, GCY-9 is in both the stem and bag, but in the mutant it is restricted almost exclusively to the bag and barely overlaps with TAX-4.

Why does the glial attachment affect calcium in the cilia? Part of the answer may be structural. We found that the guanyl cyclase GCY-9 and the cGMP-activated calcium channel TAX-4 mostly overlap in normal cilia... but become mostly segregated in the absence of the glial attachment.

A graph with the x-axis labeled "time," ranging from 0 to 45 seconds, and the y-axis labeled "ciliary calcium." Two traces are shown, corresponding to wild-type and bug-1 mutant data. A gray shaded region from 10 to 12 seconds shows when the stimulus is applied. Both traces start at a baseline near zero and then rapidly rise at stimulus onset. The bug-1 trace does not rise as high as the wild type. After stimulus onset, the wild-type trace quickly decays back to baseline, but the bug-1 trace continues to slowly rise until several seconds after the stimulus is removed, and then returns to baseline as well.

Now that we had a mutant, we could ask if cilia-glia attachment affects cilia function. Niels Ringstad imaged stimulus-evoked calcium dynamics in BAG neurons with or without the glial attachment. In the cell body, calcium signaling still looked normal - but, in the cilium, not so much.

Micrograph showing a purple neuron with an arrow pointing to its ciliated ending. BUG-1 protein, in green, covers the cilium.

BUG-1 is a large secreted protein. In mutants lacking BUG-1, neuronal cilia are still present, but they completely fail to attach to their glial partner. BUG-1 localizes at the cilia-glia attachment site, appearing to coat the cilia.

A one-eyed black cat in repose.

Our mutant led us to a previously uncharacterized gene that we named BUG-1, for (B)AG-(U)RX (g)lia attachment.

The screen was done by a postdoc, Leland Wexler, who led the entire project. On a completely unrelated note, here is a picture of Leland's cat Bug.

Micrographs of wild-type and mutant C. elegans, showing a blue neuron with a red cilium attaching to a yellow glial cell in wild type, and failing to attach in the mutant.

The power of C. elegans is that you can take a phenomenon you know nothing about and use genetics to discover the underlying molecules.

We found that two neuron types (BAG and URX ) use their cilia to attach to a specific glial partner. We isolated a mutant where cilia fail to attach to the glia.

It builds on beautiful electron microscopy by Shu-Hsien Sheu, David Clapham, Carolyn Ott and Jennifer Lippincott-Schwartz, the Lichtman and Anton labs, and the Pigino and Solimena labs, who discovered that neuronal cilia make extensive intercellular contacts in mammalian brain (and pancreas!).

This collaboration with Niels Ringstad, Piali Sengupta @senguptalab.bsky.social and Irina Kolotuev uses classical forward genetics to crack open a tough problem:

How do cilia mediate neuron-glia attachments?

New preprint!
"A stereotyped glial attachment determines the morphology and function of neuronal cilia"
doi.org/10.64898/202...

We find that C. elegans neuronal cilia attach to glia, we identify a protein required for cilia-glia attachment, and we show that glial attachments alter cilia signaling.

Model for relationships among LPR-1, LPR-3 and SCAV-2. (A) LPR-1 and SCAV-2 function to deliver and clear, respectively, an unknown lipophilic cargo (pink circles) that helps to promote assembly or retention of LPR-3 in the aECM. It is also possible that LPR-1 and SCAV-2 transport distinct cargos that each impact LPR-3 (not shown). LPR-3 matrix association is conferred by its unique N-terminal domain (Forman-Rubinsky et al., 2017). LPR-3 is presumed to carry a different cargo (purple squares) since the LPR-1 and LPR-3 cup domains are not interchangeable (Forman-Rubinsky et al., 2017). (B) In the absence of LPR-1, cargo levels drop below the level needed to efficiently recruit or retain LPR-3 in the matrix. We infer that some amount of this cargo must still reach the aECM independently of LPR-1, but it is then actively removed by SCAV-2, keeping its levels low. (C) In the absence of both LPR-1 and SCAV-2, cargo levels are restored to homeostasis and LPR-3 can assemble in the aECM.

Opposing roles for lipocalins and a CD36 family scavenger receptor in apical extracellular matrix-dependent protection of narrow tube integrity

Read this Research Article from our special issue #DevSIextracellular by @bellefeuille.bsky.social, Meera Sundaram & colleagues.

doi.org/10.1242/dev....

there's a thousand mile gap between being evaluated as mediocre because your discoveries are not seen as important (yet) vs because your work is poorly controlled, poorly executed, or poorly interpreted.

I hosted him for a PIBS pizza talk. We got one of those ten feet long party subs and he also told us about throwing the first pitch! It was connected to the earthquake during the bay series, right? I also have another small story about him but it's not for online posting. :)

switch it from tracking NFκB activation to POP-1 and you can have every cell labeled with its AB.praapaapp type lineage identity

You know your students best, and I get the appeal. But, even if they find the course fun, I'd be wondering if an all-cat curriculum will make any of them inspired to become geneticists. Maybe? But I don't feel like that's where the most exciting discoveries have been.

A screenshot of the 'Cell biology in development' subject collection showing introductory text and an image of dividing cells.

Our Editor, @swathiarur.bsky.social, has curated a new subject collection for the journal, highlighting the intersection between developmental and cell biology.

Take a look at the collection 'Cell biology in development' here: journals.biologists.com/dev/collecti...

TEM cross sections of the cephalic sensory organ at the level of the ciliary transition zone in wild-type and mec-9(ok2853) mutants. N = 8-10 sense organs examined across 2-3 animals per genotype. Numbers in lower left corner of images indicate the number of sense organs exhibiting the phenotype shown over the total number of sense organs examined. Scale bars = 200 nm. In the cartoons, CEP and CEM neurons are yellow and blue, the sheath cell is light gray, and the lumen is dark gray. Lumenal EVs are indicated as white circles.

New preprint! An ECM gene acts cell non-autonomously from neighbor neurons to regulate ciliary function, protein
localization, extracellular vesicle shedding, and ultrastructure

@katiejacobs.bsky.social is the lead in another great collaboration w/ David Hall

www.biorxiv.org/content/10.6...

Congratulations @katiejacobs.bsky.social and @barrlab.bsky.social ! Do you think the dendrite itself is mechanosensitive not only in dauer? I always assume if a neuron has a cilium then that's where the signaling happens but maybe it's like scrolling your phone while watching TV... dual inputs.

His Harvard Lab Was Thriving. Then Came the Cuts.

NYT feature on their website's front page about our local C. elegans colleague Will Mair and NIH funding
www.nytimes.com/2026/03/13/u...

"But a herring's not green!"
"You could paint it green."

"But it doesn't hang on the wall!"
"If you nail it there, it will hang on the wall."

"But it doesn't whistle!"
Theoretician shrugs: "So, it doesn't whistle."

Theoretician says to experimentalist, "I've got a riddle for you! What's green, hangs on the wall, and whistles?"

Experimentalist thinks for a long time and says, "I give up. What's green, hangs on the wall, and whistles?"

Theoretician says, "A herring!"

As usual, March has come in like a lion and hopefully it will go out like a lamb. But did you know that's not how it is in other countries? In the Malay peninsula, March comes in like a worm-eating fernbird and goes out like a worm-eating fernbird.
Source: amthenfm.wordpress.com/tag/john-bel...

I've had that experience! But I think even at seminars it tends to be the exception, and a lot of the productive comments tend to be from people who come up to say something privately to the speaker afterwards.

Email is fine! I think as a community we tend to follow the rule of "give praise in public, criticism in private."

fwiw, Development is $0 and fully ok to submit the accepted ms yourself to PubMed

Latest in #GENETICS: Ragle et al. discovered key functions and regulatory mechanisms of MLT-11, a putative protease, in #Celegans apical extracellular matrix assembly during cuticle synthesis and molting. buff.ly/MYAd56l