Overcoming Barriers in Porcine SCNT: A Comprehensive Review of Developmental Challenges and Innovations

Porcine somatic cell nuclear transfer (SCNT) demonstrates significant potential for application in biomedical research, agricultural breeding, and xenotransplantation. However, compared to in vivo fertilized embryos, SCNT embryos exhibit suboptimal developmental capacity, higher rates of abortion, and neonatal abnormalities, which collectively hinder the large-scale application of this technology. Such developmental anomalies arise from a complex interplay of interconnected factors, primarily incomplete epigenetic reprogramming (the core driver), telomere shortening, mitochondrial dysfunction, and technical manipulation-related damage-all of which disrupt the spatiotemporal regulation of gene expression and embryonic lineage commitment. This article provides a critical and integrated review of porcine SCNT research, establishing a coherent conceptual framework that links biological mechanisms, developmental defects, diagnostic tools, and improvement strategies. We emphasize mechanistic insights into key barriers, evaluate the efficacy and limitations of existing diagnostic and therapeutic approaches, and highlight pig-specific biological features that distinguish porcine SCNT from other mammalian models. This review aims to offer a novel perspective on unresolved questions in the field and provide a rigorous reference for in-depth studies on porcine SCNT embryo development.