Wnt dynamics at the blastopore and stomodeum during sea urchin gastrulation Summary: Six Wnts (1, 5, 6, 7, 8 and 16) expressed in sea urchin embryos participate in regulating endoderm at gastrulation.

doi.org/10.1242/dev....

The link was wrong 😉

This work was supported by the National Institutes of Health NIH and to the National Science Foundation

We're grateful for the support that makes long term, data rich developmental biology possible.

#NIH #NSF #FundedScience #DevelopmentalBiology

We'd love to hear what you discover in the data!

#SeaUrchin #WntSignaling #DevelopmentalBiology #GRN #ScienceCommunication

We published this work in the journal @dev-journal.bsky.social

doi.org/10.1242/dev.20...

Want to explore the data yourself?

Check out our Shiny app for hourly scRNA-seq, interactive UMAPs, co-expression, trajectories:

urchinatlas.biology.duke.edu:3838

Nodal isn’t just patterning, it’s a gatekeeper of developmental commitment.

And if you’re interested in GRN flexibility, see our earlier paper on embryonic transfating:

📜https://doi.org/10.1242/dev.203152

This may explain why Nodal was so important in our transfating paper.

When we manipulated nodal signaling, GRN states that are normally stabilized during development became plastic again, allowing cells to reprogram.

When the dance reaches the mouth, a new partner steps in: nodal.

Wnt1 enables anterior wnt8, and wnt8 both directly activates foxA (via β‑catenin/TCF) and induces nodal at the stomodeum.

Nodal then brings in gooscoid, which is required for foxA and brachyury

a close up of a pink minion car from the movie minions ALT: a close up of a pink minion car from the movie minions

Despite all the apparent rings, there is only one truly sharp boundary:

Wnt1 outside the blastopore. Wnt6/7/16 inside.

Elsewhere, expression is graded and overlapping

🪩wnt1 KD fails to block the pattern of wnt1 expression
🪩wnt8 KD reduces but fails to block the pattern of wnt8 expression
🪩wnt7 KD inhibits foregut expression of wnt5 but has no effect on wnt5 expression in the ectoderm
🪩wnt5 KD reduces foregut-midgut expression of wnt7

elton john is singing into a microphone while playing the piano . ALT: elton john is singing into a microphone while playing the piano .

And the dancers cue each other.

Wnts don’t just pattern tissues, they regulate other Wnts. We tested this by perturbing Wnts with morpholinos and RNAi

Indeed, there is not one signal at a time.

Our temporal scRNA‑seq showed that many cells co‑express multiple Wnts simultaneously, and that co‑expression changes over time. #scRNAseq #bioinformatics

Inside the Wnt1 ring, the choreography calls a figure switch.

At the blastopore, cells momentarily express Wnt6, Wnt7, and Wnt16.

Crossing into the archenteron, they cast off Wnt6 and Wnt16 but retain Wnt7, making moves to the next figure in the GRN.

Before gastrulation, the Wnt1 ring expands outward as neighboring cells activate it and inner cells extinguish it.

During gastrulation, the ring shrinks, tracking the blastopore as Veg1 cells converge, express Wnt1, then turn it off inside
#gastrulation

a man is riding a bike through a circle of flames on a stage that says talent on it ALT: a man is riding a bike through a circle of flames on a stage that says talent on it

At start, one ring takes the lead. Wnt1 forms the sharpest boundary just outside the blastopore and every endoderm cell expresses it briefly before entering the gut. This is the embryo’s Ring of Fire.

You pass through once, and you don’t come out the same.

#Morphogenesis

We used multiplex HCR‑FISH, and mapped six Wnts (Wnt1, 5, 6, 7, 8, 16) across developmental stages.

Each gene turns on at a different time, then appears sequentially in neighboring cells, producing rings of expression around the blastopore. #HCR #FISH

During gastrulation, cells don’t just change position they change state.

As endoderm cells move toward and through the blastopore, the signals they receive change over time, advancing their gene regulatory networks (GRNs) step by step. #GRN #WntSignaling

It takes two to tango but gastrulation is a contra dance

Cells move through changing partners and signals, and many Wnts act together to keep the choreography coordinated in space and time.

That’s the core idea behind our new paper on gut formation in #seaurchins 🧵

Before gastrulation, the Wnt1 ring expands outward as neighboring cells activate it and inner cells extinguish it.

During gastrulation, the ring shrinks, tracking the blastopore as Veg1 cells converge, express Wnt1, then turn it off inside

a man is riding a bike through a circle of flames on a stage that says talent on it ALT: a man is riding a bike through a circle of flames on a stage that says talent on it

The first ring leads the way. Wnt1 forms the sharpest boundary and every endoderm cell expresses it briefly before entering the gut

This is the embryo’s Ring of Fire. You pass through once and you don’t come out the same.

We used multiplex HCR‑FISH, and mapped six Wnts (Wnt1, 5, 6, 7, 8, 16) across development.

Each gene turns on at a different time, then appears sequentially in neighboring cells, producing rings of expression around the blastopore.

During gastrulation, cells don’t just change position, they change state.

As endoderm cells move toward and through the blastopore, the signals they receive change over time, advancing their gene regulatory networks (GRNs) step by step.

Here at #DBSUMI2025 and excited about the new methodologies coming to the community. Automated HCRs, so cool and necessary to screen many genes in parallel

A very appropriate citation report email I got today. Happy Valentine's y'all.

Time-lapsed video of the first cleavage in a Heliocidaris erythrogramma embryo. Taken in my last research trip to Australia.

The best howls are critically endangered Red Wolf howls 🐺

Dreaming of a world where every wolf is respected 🐺

Best PPE gift from my bestie at work!

I'll be sharing my passion for sea urchins, science, bicycles, cheese, baking, nature, and standing up against narcissistic personalities from any side in the political compass. For them, I'll be nothing but gray rocks 🪨 and 🙄

Lone wolf and gravel bike in a french beach full of sea urchins, ai generated