Multiplication made easy

A new, more efficient, method of cloning mammals has been developed by Danish and Australian scientists. The technique, reported in New Scientist magazine, will be useful for farmers who wish to mass-produce animals, and could be used to clone endangered species to help to save them from extinction.

Using nuclear transfer techniques to clone animals is time-consuming, expensive and difficult. An egg needs to have its own nucleus removed and replaced with the genetic material of the cell to be cloned. But the new technique relies on cheaper equipment, can be performed faster than nuclear transfer, and has similar success rates. It works by slicing egg cells in half, then discarding the half of the egg that contains the nucleus. The cell to be cloned is then fused with the remaining half of the egg, using an electric current. This is then fused to another egg half, known as a 'cytoplast', to create a whole embryo.

The new technique has already been used to produce one healthy calf in Australia, and a number of other cows are pregnant. The ease of the technique has also meant that field studies have been carried out. However, some commentators have questioned whether the technique should be welcomed, saying that it may encourage human reproductive cloning.