Mouse study identifies hundreds of non-Mendelian epigenetic inheritance events
A large-scale mouse study has mapped epigenetic marks that violate classical inheritance rules, including what researchers describe as the first naturally occurring paramutation documented in a mammal.
A study reported via ScienceDaily describes findings from a large mouse genetics experiment in which researchers identified hundreds of inherited traits transmitted through epigenetic mechanisms — chemical modifications to DNA and associated proteins — that do not follow Mendel's laws of segregation and independent assortment.
Among the most striking findings was the identification of what the researchers characterise as the first naturally occurring paramutation in a mammal. Paramutation is a phenomenon, previously documented mainly in plants, in which one allele heritably alters the expression of a corresponding allele in the next generation, producing changes that persist across generations even after the original allele is no longer present. The study also reported cases where epigenetic marks appeared de novo — with no obvious parental origin — raising questions about the extent to which environmental exposures might introduce heritable changes outside the conventional DNA sequence.
The original primary source for this report has not yet been identified — the ScienceDaily item does not name a journal or research institution directly in the lede. Readers are advised to locate the primary publication before drawing firm conclusions. The findings contribute to a growing body of work on transgenerational epigenetic inheritance, a field that remains active and sometimes contested in mammals. The results are likely to be of particular interest to researchers working on inheritance mechanisms, evolutionary genetics, and gene–environment interactions, as well as educators and students who teach or learn classical genetics.
Plain-language version
For patients, families, and general readers. Educational only — not medical advice.
Most of what we inherit from our parents comes through DNA — the sequence of genetic letters passed from one generation to the next. But scientists have long known that some heritable changes can also travel through chemical tags attached to DNA, called epigenetic marks, without altering the underlying sequence.
A new study in mice has found hundreds of cases where these chemical marks behaved in ways that do not follow the classic rules of genetics first described by Gregor Mendel in the 19th century. Researchers also reported what they describe as the first known example of a process called paramutation — where one inherited version of a gene changes how another version behaves in future generations — occurring naturally in a mammal. Until now, this had mainly been seen in plants.
The study raises the possibility that environmental factors may influence inheritance in ways scientists are still working to understand. This is early research in mice, and it is not yet clear what, if anything, it means for human health.
This is an educational summary, not medical advice. If anything here raises questions for you, please speak with your GP or a clinical professional.
Sources
Read the original reporting — these are the public sources this summary draws from.
-
Primary source ScienceDaily · 2026-06-01Scientists discover inherited traits that break Mendel's Laws of genetics