Idoia Quintana-Urzainqui
@idoiaeu.bsky.social
EIPOD Fellow @EMBL.Brain EvoDevo. Studying brain development and evolution in sharks and other creatures 🦈 🧠#embryo2014
https://youtu.be/TU7p_34-nmo?si=JlBwcHw1qfU3GvX9
https://youtu.be/TU7p_34-nmo?si=JlBwcHw1qfU3GvX9
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!
September 2, 2025 at 5:51 PM
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!
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
September 2, 2025 at 5:51 PM
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
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!🦈💙
September 2, 2025 at 5:51 PM
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!🦈💙
Even more interesting, their location closely matched where reelin is expressed.
September 2, 2025 at 5:51 PM
Even more interesting, their location closely matched where reelin is expressed.
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!
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!
September 2, 2025 at 5:51 PM
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!
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!
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.
September 2, 2025 at 5:51 PM
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.
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.
September 2, 2025 at 5:51 PM
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.
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.
September 2, 2025 at 5:51 PM
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.
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!
September 2, 2025 at 5:51 PM
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!
Knowing that sharks have a region in their brains that’s equivalent to the dorsal pallium, we asked: do they share developmental mechanisms linked to the neocortex, like indirect neurogenesis through basal progenitors?
September 2, 2025 at 5:51 PM
Knowing that sharks have a region in their brains that’s equivalent to the dorsal pallium, we asked: do they share developmental mechanisms linked to the neocortex, like indirect neurogenesis through basal progenitors?
Diving into the pallial branch, we observed that the shark dorsalmedial pallial neurons show strong transcriptomic similarities to mouse dorsal pallium (DP). This suggests the developmental area giving rise to the mammalian neocortex existed long before the neocortex itself.
September 2, 2025 at 5:51 PM
Diving into the pallial branch, we observed that the shark dorsalmedial pallial neurons show strong transcriptomic similarities to mouse dorsal pallium (DP). This suggests the developmental area giving rise to the mammalian neocortex existed long before the neocortex itself.
We dissected the dataset further and we found that main inhibitory neuron trajectories and types are quite conserved across vertebrate evolution.
September 2, 2025 at 5:51 PM
We dissected the dataset further and we found that main inhibitory neuron trajectories and types are quite conserved across vertebrate evolution.
We built a single nucleus and spatial transcriptomics atlas of the developing catshark telencephalon. This allowed us to identify key developmental trajectories for excitatory (pallial) and inhibitory (subpallial) neurons, as well as distinct olfactory bulb cell types. @gulceserka.bsky.social
September 2, 2025 at 5:51 PM
We built a single nucleus and spatial transcriptomics atlas of the developing catshark telencephalon. This allowed us to identify key developmental trajectories for excitatory (pallial) and inhibitory (subpallial) neurons, as well as distinct olfactory bulb cell types. @gulceserka.bsky.social
Till recently, bony fish have been the main fish reference group for comparative purpose, but contrary to cartilaginous fish, they are evolutionary speedsters, with brains that have taken unique paths.
September 2, 2025 at 5:51 PM
Till recently, bony fish have been the main fish reference group for comparative purpose, but contrary to cartilaginous fish, they are evolutionary speedsters, with brains that have taken unique paths.
The transition from jawless to jawed vertebrates likely came with many brain innovations. Since we can’t peek into ancient brains, how do we study those changes? The answer: modern shark brains. Their conserved embryonic development holds clues to our deepest origins.
September 2, 2025 at 5:51 PM
The transition from jawless to jawed vertebrates likely came with many brain innovations. Since we can’t peek into ancient brains, how do we study those changes? The answer: modern shark brains. Their conserved embryonic development holds clues to our deepest origins.
Why sharks? Because they’re living time machines— whose origins go back 450 million years… long before trees existed on Earth! Back then, innovations like jaws, paired fins, and new brain structures emerged, paving the way for complex behaviours like predation.
September 2, 2025 at 5:51 PM
Why sharks? Because they’re living time machines— whose origins go back 450 million years… long before trees existed on Earth! Back then, innovations like jaws, paired fins, and new brain structures emerged, paving the way for complex behaviours like predation.
🧠🦈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.
September 2, 2025 at 5:51 PM
🧠🦈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.
Last week I had the pleasure to visit beautiful Banyuls, run some fun experiments and enjoy the sea 🌞 ⛵ . Thanks @biom-banyuls.bsky.social for hosting me, especially bluesky-less Sylvie and Ronan 🦈 😊 and @hector-escriva.bsky.social
June 20, 2025 at 9:52 PM
Last week I had the pleasure to visit beautiful Banyuls, run some fun experiments and enjoy the sea 🌞 ⛵ . Thanks @biom-banyuls.bsky.social for hosting me, especially bluesky-less Sylvie and Ronan 🦈 😊 and @hector-escriva.bsky.social
Two days to speak at this interesting conference. Looking forward to exchange and keep learning about brain evolution. And share what sharks are teaching us! 🦈 🧠
eccn2025.umh.es
eccn2025.umh.es
May 4, 2025 at 5:28 PM
Two days to speak at this interesting conference. Looking forward to exchange and keep learning about brain evolution. And share what sharks are teaching us! 🦈 🧠
eccn2025.umh.es
eccn2025.umh.es
The beauty of embryogenesis. Can you see the blood flowing in rhythm with the heartbeat? #sharkembryo 🦈
March 19, 2025 at 10:03 AM
The beauty of embryogenesis. Can you see the blood flowing in rhythm with the heartbeat? #sharkembryo 🦈
🦈 🦈 Catshark embryo (S canicula) around stage 28 🦈🦈
December 4, 2024 at 7:46 AM
🦈 🦈 Catshark embryo (S canicula) around stage 28 🦈🦈
Fluorescent and thriving shark embryo 💚 🦈 💚
November 29, 2024 at 6:03 PM
Fluorescent and thriving shark embryo 💚 🦈 💚
Pretty sunset at EMBL 😍
November 28, 2024 at 4:01 PM
Pretty sunset at EMBL 😍