Hybrid yak-cattle in situ conservation via interspecies somatic cell nuclear transfer at ultra-high-altitude region

Pien-niu, the hybrid offspring of yak (Bos grunniens) and domestic cattle (Bos taurus), possess exceptional adaptability to ultra-high-altitude environments of the Qinghai-Xizang Plateau. In situ conservation is of special significance for ultra-high-altitude region because the offsprings need to possess the ability to adapt to the unique environment. The present study was to clone Pien-niu in Xizang via interspecies somatic cell nuclear transfer (iSCNT) to practice in situ conservation of large animal at ultra-high-altitude region. Ear fibroblast cells were isolated from Pien-niu at Qushui Experimental Station (3650m above sea level), an animal live conservation farm at Xizang, and used as iSCNT donor cells. The iSCNT blastocysts were transferred into the oviduct of surrogate Pien-niu which are maintained at Qushui Experimental Station. A live cloned Pien-niu calf was born on May 12, 2025 and keeps healthy till now. Results of short tandem repeat analysis revealed that the microsatellite loci of cloned calf were completely matched with that of donor fibroblast cells. The successful cloning of Pien-niu can provide a paradigm for in situ germplasm conservation via iSCNT at ultra-high-altitude region.