Transgenic hens lay eggs with medicinal substances
Researchers at the Scottish Roslin Institute have created genetically modified chickens that produce medicinal substances in the egg white. This is how the hens produce the miR24 antibody in their eggs, which could help against skin cancer, or interferon beta-1, which is used against viruses and to treat multiple sclerosis.
The Scottish researchers led by Helen Sang used a deactivated lentivirus to insert the genetic instructions for the desired substances into the genome of roosters. They linked these sequences to regulatory units of the ovalbumin gene, the product of which makes up more than half of the protein content in egg white. Mating with normal hens resulted in a first generation of transgenic chickens, which laid eggs with altered albumen.
A second generation of chickens also carried the transgenic genetic material and laid eggs with the human proteins. In previous experiments with transgenic birds, precisely this inheritance of the desired trait had often failed. In both generations of chickens, however, the amount of the active substances produced in the egg white fluctuated greatly - depending on which chicken had laid the egg. The reason for this is still unclear.
The proteins have been filtered and purified from the eggs. In the first tests, they proved to be effective, at least in the laboratory. The researchers hope that the new method will provide a simplified and cost-effective alternative to the industrial manufacturing processes that have been used up until now.
Eleven years ago, the Roslin Institute first attracted attention when they created the first cloned sheep, Dolly. (tak)
