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Idoia Quintana-Urzainqui

@idoiaeu.bsky.social

460 followers 410 following 53 posts

EIPOD Fellow @EMBL.Brain EvoDevo. Studying brain development and evolution in sharks and other creatures 🦈 🧠Looking for group leader positions in Europe #embryo2014 https://youtu.be/TU7p_34-nmo?si=JlBwcHw1qfU3GvX9

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

🧠🦈Excited to present our latest work🧠🦈Interested in brain evolution? And shark embryos? Then read on… Our work sheds light on the deep origins of our brain’s most complex regions.

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Reposted by Idoia Quintana-Urzainqui

Arnau Sebé-Pedrós @arnausebe.bsky.social · 14d

Happy to share the Biodiversity Cell Atlas white paper, out today in @nature.com. We look at the possibilities, challenges, and potential impacts of molecularly mapping cells across the tree of life.
www.nature.com/articles/s41...

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · 29d

Thank you so much Diego! Glad you liked it :)

Idoia Quintana-Urzainqui @idoiaeu.bsky.social · 29d

Ohhhh. Mil gracias!! Me alegra mucho que lo disfrutes.

Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 8

Thank you Georgios!! 😊 💜 🦈

Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 3

Gracias!!! Qué honor! :)))

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 3

Oh! Qué bien Rodrigo! Qué disfrutes mucho la nueva etapa! :)

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 3

Thank you Cedric!

Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 3

Thanks Baptiste! :)

Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 3

Thank you Ali! :)

Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 3

Thank you so much Teresa!

Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 3

Thanks also for pointing to that study in cyclids, it is really interesting. But they compare adult to adult, if I am not mistaken

Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 3

Good point. Indeed, age and heterochronies can be important players here. Our study includes a window of development equivalent to mouse E12-14, but it looks like our "MP" is a bit less mature than the mouse MP. This can cause the correlations to be lower, not necesarily meaning a lack of homology..

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 3

Gracias Rodrigo! :)

Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

Thanks to Arendt group: Detlev, Leslie, Tobi, Nico @galicae.bsky.social and Phil. My amazing students @gulceserka.bsky.social, @anaverbanac.bsky.social,Maite and Dori. Huge thanks to the Kaessmann lab for all their support and fruitful discussions @kaessmannlab.bsky.social @evo-and-devo.bsky.social

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

We now have a unique opportunity to keep developing cartilaginous fish models. Throug their study we will be able to explore how these and other features evolved across vertebrates and uncover the molecular mechanisms driving brain evolution. Stay tuned for more discoveries and tool developments!

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

Our study moved the postulated origin of several developmental pallial features back to the jawed common ancestor. We hypothesize these features likely contributed to the increased complexity of their brains coincident with the emergence of predation.

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media.tenor.com

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

Using the plasmid, we showed that the dorsal pallial area gives rise to a layered structure aligned with the positions of Reelin and CRs. Moreover, this structure corresponds with a complex anatomical region that brings together glutamatergic and GABAergic neurons, likely forming a complex circuitry

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

We developed a protocol to label shark neural tissue with a reporter plasmid- First time this is achieved in a Cartilaginous Fish! Impossible without (bluesky-less) Maite Boersig, Isabel Rollán, Dori Torres-Sabino and Rami Reshef. The coolest shark team ever!🦈💙

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

Even more interesting, their location closely matched where reelin is expressed.

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

But where are CRs in the shark brain?
Using HCR we found them emerging from medial pallial regions, spread across the surface of the dorsal and medial pallium and near the olfactory bulb. Really similar to their locations in mammals. Thanks to @anaverbanac.bsky.social for all her HCR work!

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

Very timely, beautiful work from Maria Tosches lab @matosches.bsky.social shows CR-like cells (Tp73 positive) in a variety of vertebrates! Supporting their ancient origin. Check it out! www.biorxiv.org/content/10.1...

Evolution of Cajal-Retzius Cells in Vertebrates from an Ancient Class of Tp73+ Neurons

In the developing cerebral cortex, Cajal Retzius (CR) cells are early-born neurons that orchestrate the development of mammalian-specific cortical features. However, this cell type has not been conclu...

www.biorxiv.org

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

Key question : are shark CR cells homologous to those of mammals? Our various cross-species comparisons suggest they are. Indeed, it was the only cell type with a clear one-to-one match across the three species—supporting an ancient origin of CR cells at least in the stem of al jawed vertebrates.

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

Cajal-Retzius cells—first described by Ramón y Cajal and Gustaf Retzius—are a peculiar developmental type essential for neocortex development. They spread through the outter-most cortical layer, they express reelin, and guide the formation of the six neocortical layers, among other key roles.

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

Finally, a unique pallial cluster caught our attention. These cells showed the canonical transcriptional signature of Cajal-Retzius cells—the same signature to the one we found in mouse datasets. To our surprise, we also identified a similar cluster in the salamander dataset.

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Idoia Quintana-Urzainqui @idoiaeu.bsky.social · Sep 2

Short answer: YES! We identified a mitotic cell state in sharks that matches mouse basal progenitors both transcriptomically and anatomically. While we found key similarities, some differences hint at unique evolutionary paths in sharks and mammals. For a deeper dive, check out the full paper!

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