Researchers discover protist with unique genetic code

Researchers have discovered a previously unknown protist species, Oligohymenophorea sp. PL0344, that utilizes a unique genetic code. The organism was identified during routine experiments testing a DNA sequencing method on a sample collected from a freshwater pond in England.

Led by Dr. Jamie McGowan of the Earlham Institute in collaboration with the University of Oxford, the study revealed that the organism deviates from standard biological rules of protein synthesis. In most life forms, stop codons—specifically TAA and TAG—signal the termination of protein production. However, in this species, these two signals have been reassigned to code for distinct amino acids.

This finding challenges existing evolutionary assumptions that these two specific stop signals evolved in tandem and would typically specify the same amino acid if their function changed. The discovery demonstrates unexpected flexibility in biological systems regarding how genetic instructions are translated into proteins.