Therapeutic Cloning versus Reproductive Cloning
The issue of cloning is one that has recently drawn much debate with regard to ethical issues - and in particular the ethics of human cloning - and in many countries legislation prohibiting cloning for certain purposes has been put into place. There are currently two main functions of cloning: medical therapy (therapeutic cloning) and reproduction (reproductive cloning). In some countries, both of these types of cloning are used for research. While umbilical cord stem cells are not currently used for either type of cloning, it is very possible that cord blood stem cells will play a vital role in cloning in the future as stem cell research continues to develop.
What is Cloning?
Cloning is the process of genetic duplication; in cloning, either an entire creature (human, animal) can be reproduced, or individual cells or genes can be cloned. Different procedures have distinct regulatory bodies in place so as to monitor cloning.
While recently there has been much controversy surrounding cloning, this process has in fact existed for decades. Plants have been cloned for many years, while a tadpole was the first animal to be cloned in the 1950s. Sheep, cows and mice have also since been cloned.
Types of Cloning
Cloning can be divided into two main types: reproductive cloning and therapeutic cloning.
The objective of reproductive cloning is to create a genetic duplicate of an organism that either currently exists or that has existed in the past. This type of cloning can be used for plants and animals, as well as human cloning.
In reproductive cloning, a technique also known as Somatic Cell Nuclear Transfer (SCNT), the genetic material is removed from a donor egg so as to create an empty egg. A cell is then removed from the organism that is to be cloned, after which the nucleus of the cell is removed. The cell is then transferred into the empty donor egg and the egg is forced to divide using either chemicals or a mild electrical shock. The embryo is then transferred into the host organism\'s uterus.
Reproductive cloning is currently being used in cloning research and could one day help to repopulate endangered species.
This type of cloning is similar to reproductive cloning; however in this procedure, stem cells are removed from the dividing embryo, which is allowed to die. Cells are then removed from the patient who requires medical treatment. This cell\'s nucleus is removed and subsequently inserted into an empty donor egg. Chemicals or an electric current are used to cause the egg to divide and the resulting embryonic stem cells are removed from the embryo. These stem cells are then used to treat the patient.