Freshwater Protist Uses Stop Signals to Build Amino Acids
While testing a DNA sequencing method, researchers found an unknown protist in a pond at Oxford University. The organism uses two genetic signals that normally halt protein production to specify two different amino acids instead. This reassignment challenges assumptions about how tightly linked those signals are in evolution.
The organism, Oligohymenophorea sp. PL0344, came from a freshwater pond in Oxford University Parks. Jamie McGowan, then a postdoctoral researcher at the Earlham Institute, encountered it while testing a sequencing approach designed for very small DNA samples, perhaps from a single cell. The work appeared in PLOS Genetics in October 2023.
Protists form a vast, loosely defined collection of eukaryotes outside the animal, plant, and fungal branches. They range from microscopic single-celled forms such as amoebas, algae, and diatoms to larger organisms including kelp, slime molds, and red algae. Later studies reportedly found other code variations in related microorganisms.
This finding may influence how scientists interpret genetic data and design sequencing tools, especially for poorly studied microbes. Researchers studying protists, biotechnology, and evolutionary biology could benefit from broader awareness that genetic codes vary. It may also affect how automated gene-annotation systems handle unusual organisms, potentially reducing errors. For society, practical effects are likely indirect and long-term, as such discoveries could inform biotech or environmental microbiology, but they are unlikely to change daily life soon.