PPL Clones First Mammal From Adult Cells

PPL Therapeutics has successfully cloned a female sheep, a world first,and has achieved a milestone in its bid to become the premier company supplying therapeutic and nutritional proteins using transgenic animals. The achievement is reported in Nature (February 27).

The work was carried out in collaboration with the Roslin Institute in Edinburgh, and demonstrates the feasibility of taking a cell from the mammary tissue of an adult sheep, transferring its nuclear material to an egg which has had its genome removed, and implanting the egg into a surrogate mother. The first sheep to be cloned by this method, called Dolly (reportedly after Dolly Parton), has now been lambed and is genetically identical to the donor animal. Similar viable embryos have been obtained by implanting nuclei from fetal fibroblast cells into eggs.

This breakthrough, the first time that any newborn mammal has been derived from adult cells, has caused a wave of controversy among the popular press and animal rights activists. For PPL, it offers the possibility of using nuclear transfer to produce identical founder transgenic sheep and cows by introducing targeted genetic modifications into cultured cells, and transferring nuclei from those cells which exhibit the desired modification.