A clone of Xenopus laevis frogs derived by nuclear transplantation of nuclei originating from a single embryo. The donor nuclei were transplanted into the eggs of a wild-type pigmented female (shown) and marked by both the one-nucleolus mutation and an albino mutation; all members of the clone are male. (Reproduced with permission from Gurdon JB. 2013. Development 140: 2449–2456, © Company of Biologists.)