Single-Celled Organisms Exhibit Complex DNA Structures, Study Reveals

A groundbreaking study by researchers at Queen Mary University of London has revealed that unicellular organisms possess a more intricate DNA epigenetic code than previously thought. Published on November 18, 2025, in the journal Nature Genetics, the findings challenge existing beliefs about molecular complexity across different life forms.

Unicellular Complexity Surpasses Multicellular Life

Traditionally, multicellular organisms, including animals, plants, and humans, have been recognized for their ability to methylate cytosine bases in DNA. This epigenetic modification plays a crucial role in various biological processes, such as aging and the onset of diseases like cancer. The recent research indicates that certain “primitive” unicellular organisms also methylate both adenine and cytosine bases, suggesting a higher level of complexity.

The research team discovered that in many of these unicellular organisms, the methylation of adenine is essential for regulating gene expression, directly influencing their survival. This finding implies that these unicellular life forms may have evolved sophisticated mechanisms for gene regulation that rival those of multicellular organisms.

Implications for Disease Treatment

The implications of this discovery extend beyond basic biology. Unicellular organisms, including various parasites that pose threats to animals, plants, and humans, could be targeted for new treatments. By focusing on the methylation of adenine bases, researchers may find innovative ways to disrupt the life cycles of these parasites, potentially leading to new therapeutic options.

Dr. Alex de Mendoza, a Reader in Evolutionary Epigenomics at Queen Mary University of London and the study’s lead author, stated, “This discovery reveals that some unicellular eukaryotes have more intricate DNA methylation systems than multicellular organisms, overturning the assumption that molecular complexity increases with organismal complexity.” He emphasized the evolutionary significance of these findings and the potential for developing drugs targeting diseases caused by protists such as Trichomonas and Blastocystis.

While the application of these findings in drug development is still in the early stages, the research opens new avenues for tackling diseases associated with unicellular organisms, including those that can lead to serious health issues in humans.

As researchers continue to explore the complex world of unicellular life, the potential for groundbreaking advancements in medical science becomes increasingly tangible. This study not only enhances our understanding of genetic complexity but also holds promise for future innovations in disease management.