Fuente: PubMed "industrial biotechnology" Theriogenology. 2026 May 2;262:117936. doi: 10.1016/j.theriogenology.2026.117936. Online ahead of print.ABSTRACTIn China, the genetic diversity of indigenous pig breeds is rapidly declining because of intensive commercial breeding practices. Somatic cell nuclear transfer (SCNT) is an effective approach to restore and preserve genetic resources. SCNT donor cells are obtained from freshly collected tissues and cryopreserved after being established as cell lines. However, the immediate establishment of primary cell cultures is often not feasible due to unexpected animal mortality, sample transport delays, or laboratory processing capacity limitations. Vitrification of intact tissues offers a practical alternative in such situations, allowing the later recovery of viable donor cells for cloning and genetic conservation, as it enables the long-term storage of donor cells within their native tissue microenvironment. In this study, a simplified direct-freezing protocol for porcine ear-margin tissue was established to overcome the procedural challenges and tissue-volume constraints associated with traditional vitrification techniques. Tissue samples were cryopreserved at varying concentrations using cryoprotectant solutions supplemented with trehalose and cycloastragenol (CAG). The proliferative capacity, oxidative stress, and long-term growth characteristics of fibroblasts were assessed after thawing. A formulation containing 0.25 M trehalose and 50 μM CAG preserved tissue viability for up to 8 months and enabled fibroblast recovery with proliferation and senescence profiles comparable to those obtained from fresh tissues. Furthermore, SCNT embryos reconstructed using these cells showed cleavage rates, blastocyst formation, and blastocyst quality similar to those observed in embryos derived from fresh-cell controls. Collectively, these findings demonstrate that cryopreserved porcine ear-margin tissue can serve as a reliable reservoir of donor cells for SCNT, offering a practical approach for preserving porcine genetic resources when the immediate establishment of primary cell cultures is not practical.PMID:42114172 | DOI:10.1016/j.theriogenology.2026.117936