And finally all at SyracuseU - @shaharsu.bsky.social @jessniblo.bsky.social for protein analyses, @rmshepherd.bsky.social for culturing, & @oliverio.bsky.social for leading this effort with me!

𝘐. 𝘤𝘢𝘴𝘤𝘢𝘥𝘦𝘯𝘴𝘪𝘴 makes us think about which factors set the upper temp limit for euks and what the physical limit is - are there relatives that grow even hotter? How do euks adapt to extreme conditions?
🌋🦠

We assembled the genome of 𝘐. 𝘤𝘢𝘴𝘤𝘢𝘥𝘦𝘯𝘴𝘪𝘴 and found enriched genes that may be associated with thermophily - many involved in signaling and protein stability. 𝘐. 𝘤𝘢𝘴𝘤𝘢𝘥𝘦𝘯𝘴𝘪𝘴 proteins also have higher predicted melting temps and higher net surface charges than 𝘝. 𝘷𝘦𝘳𝘮𝘪𝘧𝘰𝘳𝘮𝘪𝘴.

We tracked the motility of 𝘐. 𝘤𝘢𝘴𝘤𝘢𝘥𝘦𝘯𝘴𝘪𝘴 across temp and found it is active up to 64°C (movie here), with most directed motion from 55-64°C🏃‍♀️! It seems to use the vermiform state to travel quickly and the amoebiform state to explore space.

While 𝘝. 𝘷𝘦𝘳𝘮𝘪𝘧𝘰𝘳𝘮𝘪𝘴 max temp is around 45°C, we found 𝘐. 𝘤𝘢𝘴𝘤𝘢𝘥𝘦𝘯𝘴𝘪𝘴 grows up to 63°C with optimal growth at 55-57°C🥵. We showed cellular replication via Ultrastructure Expansion Microscopy at 63°C. The previous limit for euks is 60°C!

Using phylogenomics, we placed the amoeba as a novel genus within #Amoebozoa, which we named 𝘐𝘯𝘤𝘦𝘯𝘥𝘪𝘢𝘮𝘰𝘦𝘣𝘢 𝘤𝘢𝘴𝘤𝘢𝘥𝘦𝘯𝘴𝘪𝘴 (left). Its sister is 𝘝𝘦𝘳𝘮𝘢𝘮𝘰𝘦𝘣𝘢 𝘷𝘦𝘳𝘮𝘪𝘧𝘰𝘳𝘮𝘪𝘴 (right) - both have a “vermiform” and “amoebiform” state.

In 2023, we first sampled from a geothermal tributary at LVNP and using enrichment culturing, found an amoeba growing at high temp.

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 🧵

𝘐. 𝘤𝘢𝘴𝘤𝘢𝘥𝘦𝘯𝘴𝘪𝘴 makes us think about which factors set the upper temp limit for euks and what the physical limit is - are there relatives that grow even hotter? How do euks adapt to extreme conditions?
🌋🦠

We assembled the genome of 𝘐. 𝘤𝘢𝘴𝘤𝘢𝘥𝘦𝘯𝘴𝘪𝘴 and found enriched genes associated with thermophily - many involved in signaling and protein stability. 𝘐. 𝘤𝘢𝘴𝘤𝘢𝘥𝘦𝘯𝘴𝘪𝘴 proteins also have higher predicted melting temps and higher net surface charges than 𝘝. 𝘷𝘦𝘳𝘮𝘪𝘧𝘰𝘳𝘮𝘪𝘴.

We tracked the motility of 𝘐. 𝘤𝘢𝘴𝘤𝘢𝘥𝘦𝘯𝘴𝘪𝘴 across temp and found it is active up to 64°C (movie here), with most directed motion from 55-64°C🏃‍♀️! It seems to use the vermiform state to travel quickly and the amoebiform state to explore space.

While 𝘝. 𝘷𝘦𝘳𝘮𝘪𝘧𝘰𝘳𝘮𝘪𝘴 max temp is around 45°C, we found 𝘐. 𝘤𝘢𝘴𝘤𝘢𝘥𝘦𝘯𝘴𝘪𝘴 grows up to 63°C with optimal growth at 55-57°C🥵. We showed cellular replication via Ultrastructure Expansion Microscopy at 63°C. The previous limit for euks is 60°C!

Using phylogenomics, we placed the amoeba as a novel genus within #Amoebozoa, which we named 𝘐𝘯𝘤𝘦𝘯𝘥𝘪𝘢𝘮𝘰𝘦𝘣𝘢 𝘤𝘢𝘴𝘤𝘢𝘥𝘦𝘯𝘴𝘪𝘴 (left). Its sister is 𝘝𝘦𝘳𝘮𝘢𝘮𝘰𝘦𝘣𝘢 𝘷𝘦𝘳𝘮𝘪𝘧𝘰𝘳𝘮𝘪𝘴 (right) - both have a “vermiform” and “amoebiform” state.

In 2023, we first sampled from a geothermal tributary at LVNP and using enrichment culturing, found an amoeba growing at high temp.