Goldie is a 'knock-out'

A miniature piglet lacking both copies of a gene that would cause its organs to be rejected if transplanted into humans has been cloned by a US-based company. While pigs that have had these genes 'knocked-out' have been cloned before, the organs of the miniature pig are similar in size to human organs, potentially bringing the prospect of xenotransplantation closer.

Immerge BioTherapeutics announced the birth of the piglet, who is called Goldie, at a conference in new Zealand. Goldie lacks both copies of a gene that produces an enzyme called alpha 1-3 galactosyl transferase. This enzyme causes pig organs to be coated with a sugar that the human immune system recognises as foreign. Knocking out the gene therefore reduces the likelihood of the pig organs being rejected if transplanted into humans.

Professor Randall Prather, who conducted the research at the University of Missouri-Columbia, US, in partnership with Immerge, is hoping that the cloning technique will bring the possibility of xenotransplantation closer to reality. He hopes to develop a herd of miniature pigs that can be used as a safe source for human transplantation, consequently providing some solution to the shortage of human organs and tissues available for transplant. Immerge plan to start trials using transplanted tissue from 'knock-out' pigs in primates.