Scientists at Edinburgh's Roslin Institute, famous for the pioneering cloning of Dolly the sheep, have created a breed of genetically-modified hens which can produce drugs in their eggs that can treat multiple sclerosis, skin cancer and arthritis.

The research, published in the current issue of the journal Proceedings of the National Academy of Sciences and carried out by Helen Sang’s team at Roslin in collaboration with Oxford BioMedica and the Scottish subsidiary of US biotechnology firm Viragen, involved using transgenic hens as bioreactors that could lead to efficient and economical production of human pharmaceutical protein-based drugs in their eggs.

The team took 500 ISA Brown hens and added human genes to their DNA to produce proteins which are secreted into the whites of the hen's eggs. The proteins were miR24, a monoclonal antibody developed by Viragen with the potential for treating melanoma and possibly arthritis, and human interferon b-1a.

The amounts of protein produced were said to be close to those needed for commercial use, and the researchers added that they have created five generations of hens which are all producing high concentrations of pharmaceuticals.

They also noted that “many human therapeutic proteins, such as monoclonal antibodies, are produced in industrial bioreactors, but setting up such systems is both time-consuming and expensive," so their technique could allow greater production of specialised drugs at a fraction of the cost of conventional manufacturing methods.