A geothermal amoeba sets a new upper temperature limit for eukaryotes

Hannah B. Rappaport; Natalie A. Petek-Seoane; Tomáš Tyml; Jessica K. Niblo; Felix Mikus; Naomi E. Gilbert; Kurt M. LaButti; Godwin Ani; Ethan MacVicar; Rachel M. Shepherd; Ignacio de la Higuera; Samuel J. Lord; Gautam Dey; Gordon V. Wolfe; Omaya Dudin; Laura A. Katz; Kenneth Mark Stedman; Shahar Sukenik; Kristen Skruber; Frederik Schulz; R. Dyche Mullins; Angela Oliverio

doi:10.1016/j.cell.2026.08.043

MicrobiologyCellSep 22, 2026

Peer-reviewed journal article

A geothermal amoeba sets a new upper temperature limit for eukaryotes

Hannah B. Rappaport iD, Natalie A. Petek-Seoane iD, Tomáš Tyml iD, Jessica K. Niblo iD, Felix Mikus iD, Naomi E. Gilbert, Kurt M. LaButti iD, Godwin Ani iD, Ethan MacVicar iD, Rachel M. Shepherd iD, Ignacio de la Higuera iD, Samuel J. Lord iD, Gautam Dey iD, Gordon V. Wolfe iD, Omaya Dudin iD, Laura A. Katz iD, Kenneth Mark Stedman iD, Shahar Sukenik iD, Kristen Skruber iD, Frederik Schulz iD, R. Dyche Mullins iD, Angela Oliverio iD

Abstract

The study of temperature limits has transformed our knowledge of the boundaries of life but has been largely focused on bacteria and archaea. We isolated a novel geothermal amoeba, Incendiamoeba cascadensis, that divides at 63{degrees}C (145.4{degrees}F), establishing a new record for the upper temperature limit across all eukaryotes. We demonstrated cellular proliferation with growth experiments and visualized mitosis via expansion microscopy. Using high-temperature live-cell imaging, we quantified movement up to 64{degrees}C. We assembled the genome of I. cascadensis and using comparative genomics found an enrichment of genes related to proteostasis, genome stability, and sensing the external environment. Taken together, our findings challenge the current paradigm of temperature constraints on eukaryotic cells and reshape our understanding of where and how eukaryotic life can persist.

PDF DOI