piRNA-mediated silencing of exogenous retrovirus in mouse spermatogonial stem cells.
piRNA and Trp53 jointly protect mouse spermatogonial stem cells from viral invasion, with Trp53 deficiency increasing germline viral transmission by 2- to 3-fold.
- Why it matters: Germline viral integration threatens genome stability across generations, but the molecular mechanisms defending against this are not fully understood, risking heritable mutations and disease.
- What they did: The study examined how piRNAs and Trp53 regulate antiviral responses in SSCs, using gene knockouts and viral infection models to analyze piRNA production, epigenetic modifications, and viral gene expression.
- The result: Findings reveal a piRNA-MAGEA5-TRP53 axis that limits viral invasion, with Trp53 loss leading to decreased epigenetic silencing and increased germline viral transmission, highlighting a critical safeguard for genome integrity.