Cloning like rabbits

Magicians are not the only people performing tricks with rabbits. In the April issue of Nature Biotechnology, Patrick Chesné and researchers at the Institut National de la Recherche Agronomique (INRA), in France, report the first successful cloning of rabbits (Nature Biotechnology 20:366-369). Rabbits have been notoriously resistant to attempts at somatic cloning. Chesné et al. overcame the technical limitations by paying particular attention to the species-specific characteristics of oocyte physiology and early embryonic development. They had to shorten the time used for oocyte activation and delay the embryo transfer to improve implantation efficiencies. The addition of rabbits to the cloned menagerie suggests that any mammalian species can probably be cloned if the physiology and oocyte cell cycle are carefully considered.