The Process of Cloning
Cloning animals is a reliable way of maintaining high quality livestock to supply our nutritional needs. Identifying and reproducing superior livestock genetics ensures that herds are maintained at the highest quality possible. Animal cloning provides great benefits to consumers, farmers, and endangered species. Cloning also allows farmers and ranchers to accelerate the reproduction of their most productive livestock in order to better produce safe and healthy food. Cloning reproduces the healthiest animals, thus minimizing the use of antibiotics, growth hormones and other chemicals. Cloning can be used to protect endangered species. For example, in China, panda cells are being kept on reserve should this species' numbers be threatened by extinction.
The most common cloning method, known as "somatic cell nuclear transfer" or simply "nuclear transfer," requires two kinds of cell. One of the cell is a somatic cell, which is collected from the animal that is to be cloned (known as the "genetic donor"). A somatic cell is any cell that contains the complete DNA, or genetic blueprint, of the animal it came from.
The other kind of cell required for cloning is an egg cell, which is collected from a female of the same species. In the lab, a scientist extracts and discards the nucleus of the egg cell, which is the part of the cell that contains the egg donor's genes. The scientist then inserts the somatic cell from the genetic donor into the egg and combine the two cells with electricity. The resulting fused egg contains the genetic donor's DNA.
The scientist stimulates the fused egg, which activates the egg and causes it to divide just as an egg. The activated egg is then placed in a culture medium. As cellular division continues over the course of several days, an early-stage embryo (blastocyst) forms. After about a week, an embryo transfer specialist transfers the blastocyst to a recipient female where it continues to develop. After a full-term pregnancy, the recipient gives birth to an animal that is essentially the identical twin of the genetic donor.