Production of cloned NIBS (Nippon Institute for Biological Science) and α-1, 3-galactosyltransferase knockout MGH miniature pigs by somatic cell nuclear transfer using the NIBS breed as surrogates.

BACKGROUND: Nuclear transfer (NT) technologies offer a means for producing the genetically modified pigs necessary to develop swine models for mechanistic studies of disease processes as well as to serve as organ donors for xenotransplantation. Most previous studies have used commercial pigs as surrogates. METHOD AND
RESULTS: In this study, we established a cloning technique for miniature pigs by somatic cell nuclear transfer (SCNT) using Nippon Institute for Biological Science (NIBS) miniature pigs as surrogates. Moreover, utilizing this technique, we have successfully produced an α-1, 3-galactosyltransferase knockout (GalT-KO) miniature swine. Fibroblasts procured from a NIBS miniature pig fetus were injected into 1312 enucleated oocytes. The cloned embryos were transferred to 11 surrogates of which five successfully delivered 13 cloned offspring; the production efficiency was 1.0% (13/1312). In a second experiment, lung fibroblasts obtained from neonatal GalT-KO MGH miniature swine were used as donor cells and 1953 cloned embryos were transferred to 12 surrogates. Six cloned offspring were born from five surrogates, a production efficiency of 0.3% (6/1953).
CONCLUSIONS: These results demonstrate successful establishment of a miniature pig cloning technique by SCNT using NIBS miniature pigs as surrogates. To our knowledge, this is the first demonstration of successful production of GalT-KO miniature swine using miniature swine surrogates. This technique could help to ensure a stable supply of the cloned pigs through the use of miniature pig surrogates and could expand production in countries with limited space or in facilities with special regulations such as specific pathogen-free or good laboratory practice.