Cloning is the process of producing genetically identical individuals. Cloning of plants started hundreds or even thousands of years ago. However, cloning of animals started in the 1950’s but successful human cloning is yet to happen.
The first ever artificial embryo twinning was demonstrated in 1885. However, the first nuclear transferthat was successful was of a frog and took place in 1952. By the early 1980’s, embryonic cell techniques became more popular in cloning laboratory animals including livestock and mice. In 1975, scientists created the first mammalian embryo of a rabbit by nuclear transfer. Later in 1984, researchers created the first mammal by nuclear transfer (sheep). In 1987, scientists proved that even cows could be cloned.
By the late 1990’s, scientists had now developed cloning methods which used adult animal cells. However, the birth of the sheep named Dolly, in 1997 symbolized a major breakthrough in science and technology.
Keith Campbell and Ian Wilmut created a lamb by transferring the nucleus from an adult sheep’s udder cell into an nucleated egg. This led to cloning of many other animals including mice and cows. A pig was cloned in 2002 using an adult body cell, creating a litter of five clones.
More importantly, these advances raised the possibility that one day human cloning will be possible. However, this has met different reactions from people and governments due to ethical and medical concerns. Many nations even banned government-funded research into human cloning. In 2002, Clonaid, a cloning company claimed that a clone human baby was born. However, no human cloning has been scientifically confirmed to date.
Nevertheless, research has continued and in 2013, Shoukhrat Mitalipov and collegues became the first to create human embryonic stem cells by transfer of somatic cell nuclear. These stem cells were used on an 8-month old who suffered a rare genetic disorder called Leigh syndrome. Now clones are being created for therapeutic purposes though had the most recent one been implanted into a surrogate mother, it could have developed into a fetus. However, human reproductive cloning remains illegal in most countries.