uPEn: Upgraded Prime Editing Boosts Gene Modification in Livestock

Researchers have unveiled uPEn [upgraded Prime Editor], an enhanced prime editing technology that improves the efficiency and precision of genome modifications, surpassing traditional CRISPR/Cas9 methods. This advancement holds implications for agriculture and biomedical research, particularly in livestock. uPEn addresses limitations of standard prime editing by incorporating a ubiquitin variant, i53, which enhances genome stability. Experiments on mouse and sheep zygotes demonstrated uPEn's ability to insert a consensus Kozak sequence into the PPARG (γ2) gene, crucial for fat deposition. Mouse models showed increased PPARγ2 expression in adipocytes. In Hu sheep, uPEn facilitated simultaneous knock-in and knockout edits of PPARG and MSTN genes, with MSTN regulating muscle growth. Some MSTN-knockout lambs exhibited muscle hypertrophy. Next-generation sequencing (NGS) confirmed the precision of these modifications with minimal off-target effects and effective germline transmission. This technology could revolutionize livestock breeding by enhancing desirable traits and improving food production. It also shows promise for disease modeling and gene therapies. Future plans include integrating high-fidelity Cas9 variants and optimizing RNA designs to further enhance editing precision and efficiency.