What is reproductive cloning?
If an egg generated by somatic cell nuclear transfer (see ‘What is somatic cell nuclear transfer?’) was implanted into the womb of an animal, an individual would be born that has identical genetic material as the donor somatic cell and might be referred to as a ‘clone’. The procedure is referred to as ‘reproductive cloning’ and is fraught with profound technical and biological problems. The overwhelming consensus of the world’s scientific and medical communities is that at this time human reproductive cloning should be banned.
In reproductive cloning, SCNT is used to create a nuclear transfer product that is then implanted into a uterus to generate a pregnancy. These nuclear transfer products rarely develop normally and are rarely able to establish a pregnancy. Nonetheless, this is the process used to create Dolly the famous cloned sheep — after hundreds of unsuccessful attempts. A human being has never been cloned, and it is the overwhelming consensus among U.S. scientists that human reproductive cloning should be banned. Animal-cloning experiments demonstrate that reproductive cloning is unsafe: Pregnancies are rare, and when they do occur they often produce abnormal or unhealthy offspring. Most scientists believe that implanting an SCNT-derived product into a woman’s uterus should be illegal.
The aim of reproductive cloning is to generate another organism with identical genetic characteristics. This is achieved by transferring a nucleus from an adult cell into an egg from which the nucleus has been removed (SCNT). Stimulation of this cell then allows the beginning of the cell division process. Ultimately, an embryo is created and is transferred into the uterus of a female host.
