Technology used for cloning and the advantages/disadvantages
Technology used for somatic cell nuclear transfer:
Advantages of somatic cell nuclear transfer:
Disadvantages of somatic cell nuclear transfer:
- Somatic cell nuclear transfer (SCNT) involves the nucleus from a somatic body cell being transferred to the cytoplasm of an enucleated egg (an egg that has had its own nucleus removed). Once the somatic nucleus is inside the egg it is reprogrammed by egg cytoplasmic factors to become a fertilized egg (zygote) nucleus. The egg is allowed to develop to the blastocyst stage where embryonic stem cells can be created from the inner cell mass of the blastocyst. Mouse, monkey and human embryonic stem cells have been made using SCNT.
- Reproductive cloning occurs by implanting a SCNT derived blastocyst into the uterus of a surrogate mother, where the embryo develops into a fetus.
- The SCNT technique was used to create the first cloned mammal, Dolly the sheep.
- Somatic cell nuclear transfer is permitted in Australia under a license issued by the Embryo Research Licensing Committee (NHMRC).
Advantages of somatic cell nuclear transfer:
- The SCNT technique has the potential to be used to reproduce extinct species. For example, cells collected from a frozen woolly mammoth could be used as nuclear donors for enucleated elephant eggs. This advantage of SCNT has been proved to work by an experiment conducted on mice. Mice were cloned using somatic cell nuclei derived from mouse that had been frozen for more than 15 years.
Disadvantages of somatic cell nuclear transfer:
- A disadvantage of SCNT is that it is a inefficient process with majority of studies reporting between 0.5 - 5% develop correctly. Loss of fetuses and young occur throughout gestation, at birth and following birth with a range of developmental abnormalities being reported. Reasons for these abnormalities occurring is unknown but may reflect incomplete or inappropriate reprogramming.