Overexpression of the pioneer transcription factor Nr5a2 promotes the development of mouse somatic cell nuclear transfer embryos

Somatic cell nuclear transfer (SCNT) is a valuable tool in regenerative medicine, yet its efficiency remains limited by epigenetic reprogramming barriers that have been partially corrected by global regulation of epigenetic enzymes. However, these approaches lack gene locus specificity and may disrupt normal gene regulation. Therefore, new strategies capable of broadly enhancing reprogramming fidelity are needed. Here, we demonstrate that overexpression of the pioneer transcription factor Nr5a2 in mouse SCNT embryos improves both zygotic genome activation and the morula-to-blastocyst transition, two major developmental barriers in SCNT, and enhances birth rates. Mechanistically, Nr5a2 recruits P300 to increase H3K27ac at genes with low expression, restoring transcriptional activity and promoting SCNT embryo development.