Čepička lab

A new lab photo at a conference (we will photoshop Matyáš and Aneta in later).

Congratulations to Marek (and Ivan) on receiving the Bedřich Hrozný Award for the discovery of Solarion arienae! Bedřich Hrozný was a former rector of Charles University and became famous for deciphering Hittite language in 1917, which made him the father of Hittitology.

The known diversity of anaerobic scuticociliates has just taken a big leap forward! Katka’s new paper introduces several new genera and species of marine anaerobic ciliates from our recently established family Anaerocyclidiidae. So Anaerocyclidium finally has company.

They may look modest under the microscope, but the anaerocyclidiids have plenty of interesting biology going on. One of the most striking things are their transitions from marine to freshwater environments and then back again. And to make things even more intriguing, they live in close cooperation with syntrophic endo‑ and ectosymbionts that help them survive in low‑oxygen conditions. https://link.springer.com/article/10.1007/s42995-025-00350-5

Odontostomatea is a remarkably understudied class of anaerobic ciliates. In our new paper, we provide the most comprehensive revision of the group to date, including several newly discovered species and genera, among them the striking Limnomylestoma shuriken and Mircalla polidorii. We also uncover extensive environmental diversity within odontostomateans. https://link.springer.com/article/10.1007/s42995-026-00352-x

Today is the birth anniversary of Ernst Haeckel, the father of protistology.

UV autofluorescence of methanogenic archaeal endosymbionts of the anaerobic ciliate Urostomides striatus (Armophorea: Metopida: Apometopidae).
The "empty" space in the cell center is the macronucleus.
Image by Petra Malinská, a Master’s student in Čepička lab.

Protistology Open 2026 Protistology Open 2026 will bring together experts from around the world who study protists – all eukaryotes excluding plants, animals, and fungi.

Leontynka is a genus of non‑photosynthetic green algae that we recently discovered, and which was named after a character from the Czech film Ať žijí duchové! (Long Live Ghosts!). Ivan is now a co‑author of a new paper showing that the non‑photosynthetic plastid of Leontynka still produces ATP and has undergone convergent evolution with anaerobic mitochondria:

Energy metabolism and adaptation to hypoxia in the non-photosynthetic green alga Leontynka - BMC Biology Background Leontynka is a non-photosynthetic lineage of the order Chlamydomonadales (Chlorophyta). Although many Chlamydomonadales members encode components of the anaerobic energy metabolism, studies focused on Chlamydomonadales algae thriving in hypoxia and not prospering in oxic conditions are mi...

📰 Published in Nature! 🌊🔬

Our lab is excited to share the discovery of Solarion arienae — a tiny protist with sun‑like cells and unique predatory extrusomes. This elusive organism broadens our understanding of early eukaryotic evolution and even retains ancestral mitochondrial genes such as SecA, a rare relic of the alphaproteobacterial ancestor of mitochondria.

🧬 This work led us to establish a new phylum, Caelestes, and to help define a new eukaryotic supergroup, Disparia. These findings shed light on the complexity of ancestral eukaryotic life and open new doors for exploring proto‑mitochondrial metabolism.

📖 The study was led by Marek Valt as first author and Ivan Čepička as senior author.

📖 Read the paper here: https://www.nature.com/articles/s41586-025-09750-0 (Note: the article is not Open Access — publication fees remain a major challenge in science.)

We described the ciliate class Muranotrichea in 2020 (https://www.cell.com/current-biology/fulltext/S0960-9822(20)30434-6), and so far only a few representatives are known. In our new paper, we show that the long-overlooked, but very interesting genus Spirorhynchus also belongs to this class. Enjoy light-microscopic and electron-microscopic images of Spirorhynchus verrucosus, as well as its videos and phylogenetic position here: https://www.sciencedirect.com/science/article/pii/S1434461025000458