Cloning could make the genetic engineering of animals more accurate. Today, its success depends more on the hit-or-miss technique. Until recently, the method adopted for modifying most mammals was by injecting deoxyribonucleic acid (dna) into fertilised eggs. The dna would then integrate into the animal's genome at random, with unpredictable results.
Kenneth McCreath and his team at PPL Therapeutics near Edinburgh have described in Nature (July 1) how they first grew adult sheep cells in culture and made precise changes to targeted parts of the sheep genome. The team then cloned the altered cells by fusing them with egg cells from which the nuclei had been removed, and the cells grew into embryos.
Out of the 80 embryos implanted, three lambs survived for more than six months. "Gene targeting has only ever been done in mice before," says McCreath.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.