Jordi Solana
@jordisolana.bsky.social
Stem Cell Biology and Evolution (SCBE) research group | Living Systems Institute Exeter @lsiexeter.bsky.social | One of these days, I'm going to cut you into little pieces (if you are a regenerative organism)
I will be participating in this EvoDevo course in Madrid, organised by @patrialvarezcam.bsky.social and other colleagues.
sites.google.com/view/evodevo...
I will be covering scRNA-seq, other topics are transcriptomics, ATAC-seq, phylogenomics
Registration closes on Nov 20!
Dates: Dec 15-18
sites.google.com/view/evodevo...
I will be covering scRNA-seq, other topics are transcriptomics, ATAC-seq, phylogenomics
Registration closes on Nov 20!
Dates: Dec 15-18
November 14, 2025 at 12:48 PM
I will be participating in this EvoDevo course in Madrid, organised by @patrialvarezcam.bsky.social and other colleagues.
sites.google.com/view/evodevo...
I will be covering scRNA-seq, other topics are transcriptomics, ATAC-seq, phylogenomics
Registration closes on Nov 20!
Dates: Dec 15-18
sites.google.com/view/evodevo...
I will be covering scRNA-seq, other topics are transcriptomics, ATAC-seq, phylogenomics
Registration closes on Nov 20!
Dates: Dec 15-18
With over a year and a half after we submitted, this wasn’t the fastest revision! Thanks to the reviewers and editors for putting up with us (we also moved to LSI Exeter @lsiexeter.bsky.social in the meantime) and to all authors, including those that contributed to the revision!
May 7, 2025 at 7:01 PM
With over a year and a half after we submitted, this wasn’t the fastest revision! Thanks to the reviewers and editors for putting up with us (we also moved to LSI Exeter @lsiexeter.bsky.social in the meantime) and to all authors, including those that contributed to the revision!
We can also analyse the genes that change in each dataset!
So the cell type that changes the most at both the cell proportion and gene expression levels are the recently described basal cells – likely planarians get fat too, thanks to this type.
So the cell type that changes the most at both the cell proportion and gene expression levels are the recently described basal cells – likely planarians get fat too, thanks to this type.
May 7, 2025 at 7:01 PM
We can also analyse the genes that change in each dataset!
So the cell type that changes the most at both the cell proportion and gene expression levels are the recently described basal cells – likely planarians get fat too, thanks to this type.
So the cell type that changes the most at both the cell proportion and gene expression levels are the recently described basal cells – likely planarians get fat too, thanks to this type.
So, our data shows that planarians of smaller size are enriched in head types, not just neurons. This was more or less well known.
But our data can point out the specific types, with higher resolution.
And importantly: one can think of doing the same with other organisms.
But our data can point out the specific types, with higher resolution.
And importantly: one can think of doing the same with other organisms.
May 7, 2025 at 7:01 PM
So, our data shows that planarians of smaller size are enriched in head types, not just neurons. This was more or less well known.
But our data can point out the specific types, with higher resolution.
And importantly: one can think of doing the same with other organisms.
But our data can point out the specific types, with higher resolution.
And importantly: one can think of doing the same with other organisms.
To further validate this point (revision figure!) we reanalysed data from our colleagues in the Rink lab, and found that genes expressed in the most anterior part of planarians are enriched in our small planarian samples.
www.sciencedirect.com/science/arti...
www.sciencedirect.com/science/arti...
May 7, 2025 at 7:01 PM
To further validate this point (revision figure!) we reanalysed data from our colleagues in the Rink lab, and found that genes expressed in the most anterior part of planarians are enriched in our small planarian samples.
www.sciencedirect.com/science/arti...
www.sciencedirect.com/science/arti...
But not only neurons: in general, cell types that are enriched in the head, are enriched in the small planarian samples, and viceversa.
Small planarians have comparatively more head, including all head cell types.
Small planarians have comparatively more head, including all head cell types.
May 7, 2025 at 7:01 PM
But not only neurons: in general, cell types that are enriched in the head, are enriched in the small planarian samples, and viceversa.
Small planarians have comparatively more head, including all head cell types.
Small planarians have comparatively more head, including all head cell types.
Indeed, we detect all cell clusters in all sizes. There are no size specific cell types.
We find differences consistent with previous papers. Smaller planarians have more neurons.
But, now we have higher resolution: we can identify which types of neurons (revision figure! Milo analysis)
We find differences consistent with previous papers. Smaller planarians have more neurons.
But, now we have higher resolution: we can identify which types of neurons (revision figure! Milo analysis)
May 7, 2025 at 7:01 PM
Indeed, we detect all cell clusters in all sizes. There are no size specific cell types.
We find differences consistent with previous papers. Smaller planarians have more neurons.
But, now we have higher resolution: we can identify which types of neurons (revision figure! Milo analysis)
We find differences consistent with previous papers. Smaller planarians have more neurons.
But, now we have higher resolution: we can identify which types of neurons (revision figure! Milo analysis)
So, the key basic question:
are asexual planarians of different sizes made of the same basic cell types?
Or are there size-specific cell types instead?
are asexual planarians of different sizes made of the same basic cell types?
Or are there size-specific cell types instead?
May 7, 2025 at 7:01 PM
So, the key basic question:
are asexual planarians of different sizes made of the same basic cell types?
Or are there size-specific cell types instead?
are asexual planarians of different sizes made of the same basic cell types?
Or are there size-specific cell types instead?
So, we did this with single cell methods! In principle, this should have higher resolution. We took planarians of different sizes, measured them, dissociated them and performed a single cell experiment with their cells, all together in one multiplex experiment.
May 7, 2025 at 7:01 PM
So, we did this with single cell methods! In principle, this should have higher resolution. We took planarians of different sizes, measured them, dissociated them and performed a single cell experiment with their cells, all together in one multiplex experiment.
Planarians are indeed a great model to address this, as they grow when fed but also shrink if they are starved. And thanks to Jaume’s and Rafa’s work (and others) we have some way of making sure that our data makes sense.
May 7, 2025 at 7:01 PM
Planarians are indeed a great model to address this, as they grow when fed but also shrink if they are starved. And thanks to Jaume’s and Rafa’s work (and others) we have some way of making sure that our data makes sense.
It is difficult to systematically characterise “cell types”. One can do it by morphological observation, but resolution is low. This is what J. Baguñà and R. Romero did in planarians in the 80’s at @geneticsub.bsky.social
link.springer.com/article/10.1...
Can we do this with single-cell methods?
link.springer.com/article/10.1...
Can we do this with single-cell methods?
May 7, 2025 at 7:01 PM
It is difficult to systematically characterise “cell types”. One can do it by morphological observation, but resolution is low. This is what J. Baguñà and R. Romero did in planarians in the 80’s at @geneticsub.bsky.social
link.springer.com/article/10.1...
Can we do this with single-cell methods?
link.springer.com/article/10.1...
Can we do this with single-cell methods?
Allometry of Cell Types:
Here are the Dalton Brothers, archenemies of Lucky Luke.
Joe, the shortest, has a head similar to Averell, the tallest. It is the rest of the body that changes.
But, do they have the same cell types?
And, in the same proportions?
Here are the Dalton Brothers, archenemies of Lucky Luke.
Joe, the shortest, has a head similar to Averell, the tallest. It is the rest of the body that changes.
But, do they have the same cell types?
And, in the same proportions?
May 7, 2025 at 7:01 PM
Allometry of Cell Types:
Here are the Dalton Brothers, archenemies of Lucky Luke.
Joe, the shortest, has a head similar to Averell, the tallest. It is the rest of the body that changes.
But, do they have the same cell types?
And, in the same proportions?
Here are the Dalton Brothers, archenemies of Lucky Luke.
Joe, the shortest, has a head similar to Averell, the tallest. It is the rest of the body that changes.
But, do they have the same cell types?
And, in the same proportions?
Proud to present the peer-reviewed version of our Cell Type Allometry paper, out today in Science Advances!
www.science.org/doi/10.1126/...
Are animals of different sizes made of the same cell types?
Here’s an update of the main points and revision items
(with memes!)
Thread 👇🧵
www.science.org/doi/10.1126/...
Are animals of different sizes made of the same cell types?
Here’s an update of the main points and revision items
(with memes!)
Thread 👇🧵
May 7, 2025 at 7:01 PM
Proud to present the peer-reviewed version of our Cell Type Allometry paper, out today in Science Advances!
www.science.org/doi/10.1126/...
Are animals of different sizes made of the same cell types?
Here’s an update of the main points and revision items
(with memes!)
Thread 👇🧵
www.science.org/doi/10.1126/...
Are animals of different sizes made of the same cell types?
Here’s an update of the main points and revision items
(with memes!)
Thread 👇🧵
This story has been spearheaded by @drsalamander.bsky.social in our group and @hrhorkan.bsky.social from Uri Frank’s lab @thecocodium.bsky.social . Together we have generated, analysed and interpreted the data. It has taken hours of joint discussion and several visits of Helen to our laboratory!
March 3, 2025 at 6:20 PM
This story has been spearheaded by @drsalamander.bsky.social in our group and @hrhorkan.bsky.social from Uri Frank’s lab @thecocodium.bsky.social . Together we have generated, analysed and interpreted the data. It has taken hours of joint discussion and several visits of Helen to our laboratory!
So, in summary, our data reveals that Hydractinia colony parts are made of similar cell types at different proportions, with some part specific cell types. These are key players in their coloniality, including allorecognition and biomineralization.
March 3, 2025 at 6:20 PM
So, in summary, our data reveals that Hydractinia colony parts are made of similar cell types at different proportions, with some part specific cell types. These are key players in their coloniality, including allorecognition and biomineralization.
And indeed, when we checked the localisation of these cell types (new data!) we see that they are in the stolon but right at the base of the polyps, just where they adhere to the substrate
March 3, 2025 at 6:20 PM
And indeed, when we checked the localisation of these cell types (new data!) we see that they are in the stolon but right at the base of the polyps, just where they adhere to the substrate
Prisilkin-like genes in Hydractinia are similar to those of molluscs (and other biomineralizing organisms), which are key components of the molluscan shell. So it turns out that Hydractinia might be making shell-like material to adhere to the mollusc shell.
March 3, 2025 at 6:20 PM
Prisilkin-like genes in Hydractinia are similar to those of molluscs (and other biomineralizing organisms), which are key components of the molluscan shell. So it turns out that Hydractinia might be making shell-like material to adhere to the mollusc shell.
But what are Prisilkin-like genes? They code for highly repetitive proteins. They have a signal peptide, suggesting they are secreted. They are expressed in the stolon enriched Prisilkin-like+ cells.
March 3, 2025 at 6:20 PM
But what are Prisilkin-like genes? They code for highly repetitive proteins. They have a signal peptide, suggesting they are secreted. They are expressed in the stolon enriched Prisilkin-like+ cells.
There are also cell types that are highly enriched in certain colony parts. For instance, cluster 11 is highly enriched in the stolons: we called it the Prisilkin-like+ cells. They express an array of Prisilkin-like or Shematrin-like genes
March 3, 2025 at 6:20 PM
There are also cell types that are highly enriched in certain colony parts. For instance, cluster 11 is highly enriched in the stolons: we called it the Prisilkin-like+ cells. They express an array of Prisilkin-like or Shematrin-like genes
We now show that these genes are expressed in a subcluster of what we had called conodipine+ cells, the Allorecognition cells, which also express venom proteins. These are found in the epidermis of the polyps and in the stolons.
March 3, 2025 at 6:20 PM
We now show that these genes are expressed in a subcluster of what we had called conodipine+ cells, the Allorecognition cells, which also express venom proteins. These are found in the epidermis of the polyps and in the stolons.
This is new in the revision! When two Hydractinia colonies contact each other in nature, how do they know if they are the same colony or genetically distinct organisms? It was known that they have “allorecognition genes” which dictate which colonies are histocompatible.
March 3, 2025 at 6:20 PM
This is new in the revision! When two Hydractinia colonies contact each other in nature, how do they know if they are the same colony or genetically distinct organisms? It was known that they have “allorecognition genes” which dictate which colonies are histocompatible.
To answer the question: most cell types are present in both stolons and polyps. Both have neurons, nematocytes, i-cells, etc. But in different proportions. Hydractinia uses a mix-and-match model to create different colony parts.
March 3, 2025 at 6:20 PM
To answer the question: most cell types are present in both stolons and polyps. Both have neurons, nematocytes, i-cells, etc. But in different proportions. Hydractinia uses a mix-and-match model to create different colony parts.
We decided to explore this using single cell analysis (ACME and SPLiT-seq). Enter the Hydractinia Cell Atlas: 200K cells uncovering ~38 cell types of isolated Hydractinia body parts, including feeding polyps, sexual polyps and stolons.
March 3, 2025 at 6:20 PM
We decided to explore this using single cell analysis (ACME and SPLiT-seq). Enter the Hydractinia Cell Atlas: 200K cells uncovering ~38 cell types of isolated Hydractinia body parts, including feeding polyps, sexual polyps and stolons.
But: what are the cellular bases of coloniality? In other words: are the different colony parts (polyps, stolons) made of the same cell types, different cell types, or a mixture? And how did Hydractinia evolve to adapt to this niche of cohabiting mollusc shells?
March 3, 2025 at 6:20 PM
But: what are the cellular bases of coloniality? In other words: are the different colony parts (polyps, stolons) made of the same cell types, different cell types, or a mixture? And how did Hydractinia evolve to adapt to this niche of cohabiting mollusc shells?
Coloniality is also seen in other critters such as ascidians and bryozoans, for instance. The colony is just one organism, interconnected, but it has individualized and distinct parts (called zooids) that are connected by stolons
March 3, 2025 at 6:20 PM
Coloniality is also seen in other critters such as ascidians and bryozoans, for instance. The colony is just one organism, interconnected, but it has individualized and distinct parts (called zooids) that are connected by stolons