Somatic Cell Nuclear Transfer (SCNT)
Definition - What does Somatic Cell Nuclear Transfer (SCNT) mean?
Somatic cell nuclear transfer (SCNT) is a process of cloning where an embryo is created in a laboratory setting with an egg cell that has had its nucleus removed and replaced by a donor nucleus from a somatic cell (any cell from the body other than a sperm or egg). The egg cell is then forced to divide to produce an embryo with a DNA blueprint identical to the original somatic cell. The embryo can then be transferred to a uterus.
FertilitySmarts explains Somatic Cell Nuclear Transfer (SCNT)
SCNT is performed under a microscope to remove and transfer nuclei from one cell to another. In SCNT, the nucleus, containing all genetic material, is removed from a somatic cell such as a skin cell, while the rest of the cell is discarded. The nucleus of an egg cell is also removed and discarded while the cytoplasm of the egg is maintained. The nucleus of the somatic cell is then inserted into the cytoplasm of the egg cell. The egg then adopts the DNA from the transplanted nucleus as its own. At this stage, the egg is forced to divide and results in producing an embryo. Fertilization of the egg with sperm is not required because the somatic nucleus already contains the appropriate number of chromosomes. The resulting embryo will contain a DNA makeup identical to the original somatic cell, producing a clone.
Although this process has been used to clone a variety of animals and was made famous in the cloning of "Dolly" the sheep, its use is highly controversial in human reproduction. Some consider this process in humans to be unethical because human cloning represents a departure from conception methods in which a child's genetic makeup is unique from either parent. Supporters of SCNT in human production argue that it could be useful in instances of poor egg quality in order to increase the probability of producing a viable embryo, or in an effort to avoid chromosomal congenital abnormalities.