Researchers at Gunma University in Japan have developed a CRISPR-Cas-based system to modify epigenetic marks in mouse sperm and assess whether altered DNA methylation patterns can be passed to the next generation. The team targeted the H19 differentially methylated region in sperm using a catalytically inactive Cas9 system to remove methylation without altering the underlying DNA sequence, then observed effects on offspring development. Early results showed growth changes consistent with inherited epigenetic loss in first-generation mice.
The investigation found partial restoration of methylation during early embryonic development, suggesting an epigenetic memory mechanism involving histone modifications. The researchers identified tri-methylated histone H3 at lysine 9 (H3K9me3) as a factor guiding re-establishment of methylation patterns after fertilisation, despite the original mark being erased in sperm. In subsequent generations, methylation levels returned to normal, indicating limited intergenerational inheritance at the study locus. The work offers a novel experimental tool for directly testing the controversial theory of epigenetic inheritance, which posits that experiences or environmental exposures could influence traits across generations.
Why it matters
This study introduces a direct germline epigenome editing approach to investigate epigenetic inheritance, potentially reshaping understanding of heritable biological effects beyond DNA sequence.
Source Attribution
Source: CRISPR Medicine News | Adapted & summarized
Published on: 29 December 2025
Category: Healthcare
Region: Japan
