Fig. 3.

Schematics showing the procedures used to generate cloned or semi-cloned mammals. a Cloned animals have been produced by injecting a diploid somatic cell into an enucleated oocyte followed by activation with SrCl₂ in calcium-free CZB medium supplemented with CB. b Live semi-cloned mice have been produced by injecting a secondary spermatocyte into an intact MII oocyte. c The semi-cloned embryos have been obtained by injecting a diploid somatic cell into an intact MII oocyte followed by activation in media lacking CB. However, no viable animals have been produced using this method. d, e Semi-cloned mice (or rats) have been produced by injecting an M-phase (d) or G0/G1-phase (e) AG-haESC into an intact MII oocyte or a pre-activated MII oocyte, respectively. f The procedure used to generate semi-cloned mice from PG-haESCs in place of a maternal genome. A sperm head is first injected into an oocyte, followed by the removal of the spindle. One hour later, a G0/G1-phase PG-haESC is injected to generate a diploid embryo. Then, semi-cloned embryos and mice can be produced