Sarah Guest
@sarahmoeba.bsky.social
Postdoc in the Fritz-Laylin lab, fascinated by obscure protists. Evolutionary Cell Bio research on amoebae & cytoskeleton. Sometimes art. she/her.
Reposted by Sarah Guest
Our attempt to give multinucleate cells the spotlight they deserve (seriously, they’re everywhere), led by the fearless @mrosjac.bsky.social and with @Markus Ganter
doi.org/10.32942/X2M...
We’d love your feedback while this goes through the peer review process!
#MicroEvoSky
#ProtistsonSky 🧪🌏
doi.org/10.32942/X2M...
We’d love your feedback while this goes through the peer review process!
#MicroEvoSky
#ProtistsonSky 🧪🌏
November 26, 2025 at 2:05 PM
Our attempt to give multinucleate cells the spotlight they deserve (seriously, they’re everywhere), led by the fearless @mrosjac.bsky.social and with @Markus Ganter
doi.org/10.32942/X2M...
We’d love your feedback while this goes through the peer review process!
#MicroEvoSky
#ProtistsonSky 🧪🌏
doi.org/10.32942/X2M...
We’d love your feedback while this goes through the peer review process!
#MicroEvoSky
#ProtistsonSky 🧪🌏
Reposted by Sarah Guest
So happy to announce our new preprint, “A geothermal amoeba sets a new upper temperature limit for eukaryotes.” We cultured a novel amoeba from Lassen Volcanic NP (CA, USA) that divides at 63°C (145°F) 🔥 - a new record for euk growth!
#protistsonsky 🧵
#protistsonsky 🧵
November 25, 2025 at 8:41 PM
So happy to announce our new preprint, “A geothermal amoeba sets a new upper temperature limit for eukaryotes.” We cultured a novel amoeba from Lassen Volcanic NP (CA, USA) that divides at 63°C (145°F) 🔥 - a new record for euk growth!
#protistsonsky 🧵
#protistsonsky 🧵
Our work on Naegleria Myosin 2 is out!
Naegleria encodes 3 Myo2s which contract its actin network—the first evidence of contractile Myo2 outside of Amorphea.
Myo2 is actually widespread in Naegleria's relatives and correlates with fast cell crawling.
Read more: www.cell.com/current-biol...
Naegleria encodes 3 Myo2s which contract its actin network—the first evidence of contractile Myo2 outside of Amorphea.
Myo2 is actually widespread in Naegleria's relatives and correlates with fast cell crawling.
Read more: www.cell.com/current-biol...
Myosin 2 drives actin contractility in fast-crawling species outside of the amorphean lineage
Myosin 2-dependent actin contractility—the force that powers cell division and migration
in animals, fungi, and other Amorphea—had been previously unknown outside this single
eukaryotic group. Guest e...
www.cell.com
November 17, 2025 at 5:19 PM
Our work on Naegleria Myosin 2 is out!
Naegleria encodes 3 Myo2s which contract its actin network—the first evidence of contractile Myo2 outside of Amorphea.
Myo2 is actually widespread in Naegleria's relatives and correlates with fast cell crawling.
Read more: www.cell.com/current-biol...
Naegleria encodes 3 Myo2s which contract its actin network—the first evidence of contractile Myo2 outside of Amorphea.
Myo2 is actually widespread in Naegleria's relatives and correlates with fast cell crawling.
Read more: www.cell.com/current-biol...
Reposted by Sarah Guest
Finally out! We measured mutations in tetraploid potato. Highlights:
- higher mutation rates in L1 than L2
- even higher rates and a distinct oxidative stress signature outside of meristems
- lower mutation rates in genes everywhere we looked
More 👇
www.pnas.org/doi/10.1073/pnas.2514507122
- higher mutation rates in L1 than L2
- even higher rates and a distinct oxidative stress signature outside of meristems
- lower mutation rates in genes everywhere we looked
More 👇
www.pnas.org/doi/10.1073/pnas.2514507122
PNAS
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...
nam10.safelinks.protection.outlook.com
November 10, 2025 at 9:23 PM
Finally out! We measured mutations in tetraploid potato. Highlights:
- higher mutation rates in L1 than L2
- even higher rates and a distinct oxidative stress signature outside of meristems
- lower mutation rates in genes everywhere we looked
More 👇
www.pnas.org/doi/10.1073/pnas.2514507122
- higher mutation rates in L1 than L2
- even higher rates and a distinct oxidative stress signature outside of meristems
- lower mutation rates in genes everywhere we looked
More 👇
www.pnas.org/doi/10.1073/pnas.2514507122
Reposted by Sarah Guest
An Asgard archaeon with internal membrane compartments
Brilliant study led by @fmacleod.bsky.social and Andriko von Kügelgen. Tight collaboration with @buzzbaum.bsky.social and lab. Congrats to all authors!
www.biorxiv.org/content/10.1...
Brilliant study led by @fmacleod.bsky.social and Andriko von Kügelgen. Tight collaboration with @buzzbaum.bsky.social and lab. Congrats to all authors!
www.biorxiv.org/content/10.1...
November 7, 2025 at 10:44 AM
An Asgard archaeon with internal membrane compartments
Brilliant study led by @fmacleod.bsky.social and Andriko von Kügelgen. Tight collaboration with @buzzbaum.bsky.social and lab. Congrats to all authors!
www.biorxiv.org/content/10.1...
Brilliant study led by @fmacleod.bsky.social and Andriko von Kügelgen. Tight collaboration with @buzzbaum.bsky.social and lab. Congrats to all authors!
www.biorxiv.org/content/10.1...
Reposted by Sarah Guest
Just under a month left—apply by December 5 through the link on my website!
PhD or Master's position available for Fall 2026!
Interested in how actin drives cell crawling, eating, dividing, or osmoregulation? What about pathogenesis of a brain-eating amoeba? Or eukaryotic evolution? If so, apply through my website: katrinavelle.wixsite.com/science/cont...
Please share!
Interested in how actin drives cell crawling, eating, dividing, or osmoregulation? What about pathogenesis of a brain-eating amoeba? Or eukaryotic evolution? If so, apply through my website: katrinavelle.wixsite.com/science/cont...
Please share!
November 6, 2025 at 10:34 AM
Just under a month left—apply by December 5 through the link on my website!
Reposted by Sarah Guest
🚨Our collaboration with @centriolelab.bsky.social & @gautamdey.bsky.social is out today in @cp-cell.bsky.social
We show that #Expansion #Microscopy is a broad-spectrum modality for Euks, enabling 3D phenotypic maps rooted to phylogeny.
#ProtistsOnSky #SciComm #SciSky
www.cell.com/cell/fulltex...
We show that #Expansion #Microscopy is a broad-spectrum modality for Euks, enabling 3D phenotypic maps rooted to phylogeny.
#ProtistsOnSky #SciComm #SciSky
www.cell.com/cell/fulltex...
October 31, 2025 at 2:42 PM
🚨Our collaboration with @centriolelab.bsky.social & @gautamdey.bsky.social is out today in @cp-cell.bsky.social
We show that #Expansion #Microscopy is a broad-spectrum modality for Euks, enabling 3D phenotypic maps rooted to phylogeny.
#ProtistsOnSky #SciComm #SciSky
www.cell.com/cell/fulltex...
We show that #Expansion #Microscopy is a broad-spectrum modality for Euks, enabling 3D phenotypic maps rooted to phylogeny.
#ProtistsOnSky #SciComm #SciSky
www.cell.com/cell/fulltex...
Reposted by Sarah Guest
Our lab’s variegated peperomia makes green flecks on leaves, but only on the abaxial side. It’s the typical sandwich: L1 green-L2 yellow-L3 green, so guessing flecks are L1-derived cells dividing periclinally into L2. But how only on the abaxial side? Something to do with the super thick epidermis?
October 31, 2025 at 5:31 PM
Our lab’s variegated peperomia makes green flecks on leaves, but only on the abaxial side. It’s the typical sandwich: L1 green-L2 yellow-L3 green, so guessing flecks are L1-derived cells dividing periclinally into L2. But how only on the abaxial side? Something to do with the super thick epidermis?
Just for fun, here's a game I like to call "Find the neuron" with examples of olfactory sensory neuron images from Šmít et al 2017 (doi.org/10.7554/eLif...) and Filoreta ramosa, a free-living syncytial amoeba from a salt marsh.
October 29, 2025 at 3:49 PM
Just for fun, here's a game I like to call "Find the neuron" with examples of olfactory sensory neuron images from Šmít et al 2017 (doi.org/10.7554/eLif...) and Filoreta ramosa, a free-living syncytial amoeba from a salt marsh.
My PhD work is up on bioRxiv! Read all about the #actin and #microtubule #cytoskeleton of the Rhizarian #amoeba Filoreta ramosa here: www.biorxiv.org/content/10.1...
October 29, 2025 at 3:47 PM
My PhD work is up on bioRxiv! Read all about the #actin and #microtubule #cytoskeleton of the Rhizarian #amoeba Filoreta ramosa here: www.biorxiv.org/content/10.1...
Autumn is just the best
October 25, 2025 at 4:26 AM
Autumn is just the best
Reposted by Sarah Guest
This is glorious! And diatoms are as weird as ever!
Excited to share the lab's 1rst preprint! Rapid high-res immunofluorescence is now possible in cultured & environmental diatoms thanks to 4-fold expansion microscopy. A step-change for comparative cell biology in one of the most important phytoplankton groups on the planet 🥳
tinyurl.com/m9s5su7s 1/2
tinyurl.com/m9s5su7s 1/2
June 17, 2025 at 11:59 AM
This is glorious! And diatoms are as weird as ever!
Reposted by Sarah Guest
Happy to have contributed to this great article: #Protist genomics: key to understanding eukaryotic evolution. Congrats Alexandra Schoenle et al. #ProtistsOnSky
authors.elsevier.com/sd/article/S...
authors.elsevier.com/sd/article/S...
June 13, 2025 at 6:43 AM
Happy to have contributed to this great article: #Protist genomics: key to understanding eukaryotic evolution. Congrats Alexandra Schoenle et al. #ProtistsOnSky
authors.elsevier.com/sd/article/S...
authors.elsevier.com/sd/article/S...
Reposted by Sarah Guest
Highlighted paper! Daisuke Yamagishi, et al. open a new front in the drive to understand photosymbiosis in protists.
Article➡️ doi.org/10.1111/jeu....
#protistsonsky
Article➡️ doi.org/10.1111/jeu....
#protistsonsky
June 5, 2025 at 5:49 PM
Highlighted paper! Daisuke Yamagishi, et al. open a new front in the drive to understand photosymbiosis in protists.
Article➡️ doi.org/10.1111/jeu....
#protistsonsky
Article➡️ doi.org/10.1111/jeu....
#protistsonsky
An amoeba movie I made: "hungry" #protistsonsky #amoeba
June 3, 2025 at 9:24 PM
An amoeba movie I made: "hungry" #protistsonsky #amoeba
Reposted by Sarah Guest
I contributed an essay and some images to the new Living Futures series, an outgrowth of the fantastic Living Histories series organized by Sri Biswas and others.
medium.com/@thelhseries...
iyerbiswas.com/outreach/liv...
1/3
medium.com/@thelhseries...
iyerbiswas.com/outreach/liv...
1/3
Microbial Marvels, Microscopes, Math, and Mentorship
by Ben Larson for Living Futures
medium.com
May 15, 2025 at 1:47 PM
I contributed an essay and some images to the new Living Futures series, an outgrowth of the fantastic Living Histories series organized by Sri Biswas and others.
medium.com/@thelhseries...
iyerbiswas.com/outreach/liv...
1/3
medium.com/@thelhseries...
iyerbiswas.com/outreach/liv...
1/3
Poor dude can't catch dinner #protistsonsky #amoeba
June 2, 2025 at 9:03 PM
Poor dude can't catch dinner #protistsonsky #amoeba
Reposted by Sarah Guest
There are 2 previous historical cases of countries destroying their science and universities, crippling them for decades: Lysenkoism in the USSR and Nazi Germany. The Trump administration will be the 3rd.
It's not just budgets but research, institutions, expertise, and training the next generation.
It's not just budgets but research, institutions, expertise, and training the next generation.
May 31, 2025 at 4:43 AM
There are 2 previous historical cases of countries destroying their science and universities, crippling them for decades: Lysenkoism in the USSR and Nazi Germany. The Trump administration will be the 3rd.
It's not just budgets but research, institutions, expertise, and training the next generation.
It's not just budgets but research, institutions, expertise, and training the next generation.
Reposted by Sarah Guest
The inside of our net was coated with these tiny jelly balls. I asked @blancobercial.bsky.social if they were some kind of ctenophore, but he said (enthusiastically) "No! These are #Rhizaria!" He is holding a single cell here. #marinelife #protistsonsky
March 12, 2024 at 10:29 PM
The inside of our net was coated with these tiny jelly balls. I asked @blancobercial.bsky.social if they were some kind of ctenophore, but he said (enthusiastically) "No! These are #Rhizaria!" He is holding a single cell here. #marinelife #protistsonsky
Reposted by Sarah Guest
Evidence for #recombination, and maybe #meiosis, in free-living #Rhizaria! I wish the results were clearer. As so often we raised more questions than we could answer :) If you are into #sex and the #meiosis-toolkit, this is an important read! #ProtistsOnSky link.springer.com/article/10.1...
May 23, 2025 at 8:31 AM
Evidence for #recombination, and maybe #meiosis, in free-living #Rhizaria! I wish the results were clearer. As so often we raised more questions than we could answer :) If you are into #sex and the #meiosis-toolkit, this is an important read! #ProtistsOnSky link.springer.com/article/10.1...
Reposted by Sarah Guest
New paper out in @pnas.org
We followed cells migrating along signalling gradients in 3D, and found they collectively behave as a living droplet - a self-propelling fluid that grows.
www.pnas.org/doi/10.1073/...
We followed cells migrating along signalling gradients in 3D, and found they collectively behave as a living droplet - a self-propelling fluid that grows.
www.pnas.org/doi/10.1073/...
May 21, 2025 at 10:00 AM
New paper out in @pnas.org
We followed cells migrating along signalling gradients in 3D, and found they collectively behave as a living droplet - a self-propelling fluid that grows.
www.pnas.org/doi/10.1073/...
We followed cells migrating along signalling gradients in 3D, and found they collectively behave as a living droplet - a self-propelling fluid that grows.
www.pnas.org/doi/10.1073/...
Reposted by Sarah Guest
Myosin 2 drives actin contractility in fast-crawling species outside of the amorphean lineage https://www.biorxiv.org/content/10.1101/2025.05.16.654244v1
May 19, 2025 at 10:30 AM
Myosin 2 drives actin contractility in fast-crawling species outside of the amorphean lineage https://www.biorxiv.org/content/10.1101/2025.05.16.654244v1
A quick craft project: hand-cut phase annuli from construction paper to fit an "adopted" microscope that was missing ph1 ph2 and ph3
May 28, 2025 at 8:14 PM
A quick craft project: hand-cut phase annuli from construction paper to fit an "adopted" microscope that was missing ph1 ph2 and ph3
Acanthocystis (maybe?) from the same bog sample. Sometimes amoebae don't need phase contrast, especially if they're full of zoochlorellae/plastids! #protistsonsky #bogblog
May 21, 2025 at 8:15 PM
Acanthocystis (maybe?) from the same bog sample. Sometimes amoebae don't need phase contrast, especially if they're full of zoochlorellae/plastids! #protistsonsky #bogblog