Newly Discovered Amoeba Thrives at Record-Breaking Temperatures,Challenging Limits of Eukaryotic Life
CASCADE RANGE,USA - A newly discovered amoeba,Incendiamoeba cascadensis,has shattered previous records for heat tolerance among eukaryotic organisms,surviving temperatures up to 80 degrees Celsius (176 degrees Fahrenheit). the findings, currently available as a preprint on bioRxiv, suggest life may be far more adaptable to extreme environments than previously understood, with implications for the search for extraterrestrial life.
researchers found I.cascadensis remained motile at 64 degrees Celsius,exceeding the prior amoeba record of 57 degrees Celsius held by Echinamoeba thermarum. This surpasses the long-held assumption that 60 degrees Celsius represented the upper limit for eukaryotic growth. The organism began forming protective cysts at 66 degrees Celsius, a dormancy strategy common in amoebae facing harsh conditions, and also exhibited cyst formation at a surprisingly low 25 degrees Celsius.
While movement ceased at 70 degrees Celsius, the amoeba could revive when temperatures decreased. It ultimately succumbed to heat at 80 degrees Celsius.
Genome analysis revealed I. cascadensis possesses adaptations for rapid signaling and heat-response pathways, alongside an expanded repertoire of heat-resistant proteins and heat-shock chaperones. Environmental DNA samples from Yellowstone National Park and the Taupō Volcanic Zone in New Zealand contained nearly identical DNA sequences, hinting at the potential presence of related organisms in those locations.
“Incendiamoeba cascadensis proliferates at temperatures beyond what was thought possible for any eukaryotic organism,” the researchers wrote in their preprint. “These results have profound implications for our understanding of the evolutionary constraints on eukaryotic cells and the set of abiotic parameters that inform the search for life elsewhere in the Universe.”
The discovery raises new questions about the maximum temperature a eukaryotic cell can endure and could inform assessments of habitability on alien worlds.
