On 13 October 2001, a laboratory in the United States produced the first cloned human embryo by the process of nuclear transplantation.
But, why would we want a cloned human embryo?
The cloned embryo could either be:
- implanted into a uterus to grow into a whole organism (called reproductive cloning)
- harvested for embryonic stem cells that are used to grow into any type of tissue, (called nuclear transfer technology and previously known as therapeutic cloning).
All forms of human cloning are illegal in Australia.
Nuclear transfer - cloning human cells for therapy
Nuclear transfer does not result in pregnancy or the birth of a cloned baby. Instead, embryonic stem cells are removed at a very early stage and grown in the laboratory, until there are enough to be stimulated to develop into other human cell types like skin or muscle cells. This is the basis of stem cell research.
Stem cells could be used in many applications, including production of healthy cells to replace damaged cells in the body, or growth of organs for organ transplants.
Although nuclear transfer holds great potential as a mechanism to treat and cure diseases, it is also very controversial. This is because the embryo is destroyed when the stem cells are removed.
For this reason, research is currently focused on collecting stem cells from other sources, such as cord blood and adult tissues. These sources do not require the production of a cloned human embryo, and are therefore less controversial.
In Australia, nuclear transfer is illegal, because it is a form of cloning a human embryo.
Reproductive cloning - cloning a whole human
The aim of reproductive cloning is to produce a living clone of a human from their DNA. This technology is illegal in many countries around the world. The technique is not well established, and a number of ethical issues need to be discussed first.
The Australian Government, in agreement with most other countries, is opposed to the cloning of human beings for reproductive purposes, and has passed the Prohibition of Human Cloning Act 2002 (Cth).
The success rate of animal reproductive cloning is still very low, Many attempts are needed before a cloned embryo is formed, each time using hundreds of donor and egg cells. Cloned animals have presented a number of abnormalities in both their genes and development.
At present, the scientific community in general considers human cloning to be unethical, because of the safety and social concerns.
The possible uses of reproductive cloning could be to:
- reproduce endangered wildlife
- produce children for people who are unable to have a child
- clone a child that may have passed away.