PPL Therapeutics, the Scottish biotechnology company where Dolly the sheep was cloned, has bred two transgenic sheep using a new technique called gene targeting. The lambs - called Cupid and Diana - have a human gene in their DNA allowing them to produce human proteins in their milk that could be used in new drugs. The new technique developed at PPL allows scientists to replace one gene with another at a precise location on a chromosome.
Gene targeting, for which PPL has filed patent applications, will allow researchers to breed transgenic animals more quickly and efficiently. Dr Ron James, managing director of PPL, refused to say which gene had been inserted into the lambs as this might give competitors a clue as to the technique. However, Dr James did comment that the breakthrough has brought PPL a step closer to successful xenotransplantation, which could lead to the use of animal organs for human transplantation. PPL hopes to license out the technology. Potential customers could include drug companies keen to create animals models of human diseases on which to test new drugs.