Perseverance leads to cloned pig in Japan. A. Onishi et al. Pig cloning by microinjection of fetal fibroblast nuclei. I. A. Polejaeva et al. Cloned pigs produced by nuclear transfer from adult somatic cells.
Pigs is pigs.
T. Wakayama et al. Cloning of mice to six generations. News Europe asks UK to reject cloning approval . Production of cloned pigs from in vitro systems. Elizabeth Pennisi and Gretchen Vogel.