There’s been a lot of excitement and hype surrounding the extent to which our epigenetic information is passed on to subsequent generations, but our work suggests that it’s not as pervasive as was previously thought
- Tessa Bertozzi
The explanation that has gained most currency for how this occurs is so-called ‘epigenetic inheritance’ – patterns of chemical ‘marks’ on or around our DNA that are hypothesised to be passed down the generations. But new research from the University of Cambridge suggests that this mechanism of non-genetic inheritance is likely to be very rare.
A second study, also from Cambridge, suggests, however, that one way that environmental effects are passed on may in fact be through molecules produced from the DNA known as RNA that are found in a father’s sperm.
The mechanism by which we inherit innate characteristics from our parents is well understood: we inherit half of our genes from our mother and half from our father. However, the mechanism whereby a ‘memory’ of the parent’s environment and behaviour might be passed down through the generations is not understood.
Epigenetic inheritance has proved a compelling and popular explanation. The human genome is made up of DNA – our genetic blueprint. But our genome is complemented by a number of ‘epigenomes’ that vary by cell type and developmental time point. Epigenetic marks are attached to our DNA and dictate in part whether a gene is on or off, influencing the function of the gene. The best understood epigenetic modification is DNA methylation, which places a methyl group on one of the bases of DNA (the A, C, G or T that make up our genetic code).
Image: Agouti mice
Credit: Randy Jirtle and Dana Dolinoy
Reproduced courtesy of the University of Cambridge