The research carried out at the Roslin Institute is the first in which the complete genetic material from an adult mammalian cell has been used in the development of an identical new individual.
The technique involves several steps. First, the donor cells are grown under special conditions in culture. In this way the number of cells can be increased by several orders of magnitude. It is also possible to make genetic modifications and to select just those cells in which the desired modification has occurred. The selected cells are then fused with an unfertilised egg from which the introduced nucleus can lead to the formation of an embryo. The embryos are then transplanted into female sheep and the lambs are born naturally.
This technology could allow the production of genetically identical groups of
animals which possess a desirable genetic trait. PPL Therapeutics hopes to use
this technique to enable the production of new drugs.