Researchers have uncovered an unexpected biological mechanism that may expand the way inheritance is understood. While studying nematode worms at the University of Toronto, Matthew Eroglu and his team found that certain traits were being passed across generations without changes to DNA or RNA.
The discovery emerged during cancer-signaling research in C. elegans, a tiny worm often used to explore fundamental biology. The worms gradually became less fertile and more female-like over generations, until some stopped producing sperm. The team traced the shift to unusual protein clumps inside reproductive cells, which they named herasomes.
These structures were built from amyloid-like proteins, a class of proteins usually discussed in the context of neurodegenerative disease, but here appearing to play a biological role in inheritance. When two genes, mstr-1 and mstr-2, were altered, the protein aggregates accumulated and influenced sex determination. Even more striking, the effect could be passed on to later generations while the worms' genetic code stayed unchanged.
This makes the finding especially important for epigenetics, the field that studies how traits can be inherited through mechanisms beyond DNA sequence. Scientists have already identified small RNA molecules and chromatin changes as part of that story. Now, proteins may represent another layer.
According to the researchers, this is the first clear evidence that proteins themselves can act as carriers of inherited information. The result may help explain part of the long-standing puzzle often called missing heritability, where family traits and disease risks are not fully accounted for by known genetic variants.
For now, the work has been demonstrated in worms, not humans. But it opens a wider question: could similar protein-based inheritance exist in mammals, and perhaps influence development or disease risk in ways DNA alone cannot explain? Future studies will focus on how these structures form, persist, and shape biology across generations. The discovery suggests that heredity may be more layered and dynamic than once imagined, with possible implications for the future of genetics and medicine.