Nuclear+Transfer

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Have you ever wished you could have a clone of yourself to do homework while you hit the skate park or went out with your friends? Imagine if you could really do that. Where would you start? This page might not help you out with that, but it will teach you how it has been used in the past and how people are attempting in using it for the future = = = =

= = = = = = =Cloning= = = What is cloning? //Cloning// is the process of creating identical organisms from an original. //Nuclear transfer// is a type of cloning. It involves removing the DNA of an egg, and inserting the nucleus of another cell; in this case, to make a pluripotent stem cell.



=SCNT=

//Somatic cell nuclear transfer//, (SCNT) uses a different approach than artificial embryo twinning, but it produces the same result: an exact clone, or genetic copy, of an individual. This was the method used to create Dolly the Sheep.What does SCNT mean? Let's take it apart:: A somatic cell is any cell in the body other than the two types of reproductive cells, sperm and egg. Sperm and egg are also called germ cells. In mammals, every somatic cell has two complete sets of chromosomes, whereas the germ cells only have one complete set.: The nucleus is like the cell's brain. It's an enclosed compartment that contains all the information that cells need to form an organism. This information comes in the form of DNA. It's the differences in our DNA that make each of us unique.: Moving an object from one place to another.

=History=

The nucleus contains the information needed for returning the cell to its original state so it can become any cell in the body. //Nuclear transfer// requires two cells, a donor cell and an oocyte, or egg cell. Research has proven that the egg cell works best if it is unfertilized, because it is more likely to accept the donor nucleus as its own. Nuclear transfer works best when the egg cell is in the G0 Phase, or dormant phase. //Cloning// was one of the ways that scientists attempted in making embryonic stem cells. Before scientists started using IPSCs to try and create stem cells, they thought that nuclear transfer was the only possible answer. Nuclear transfer has been utilized for a variety of functions. The two primary ways are by therapeutic and reproductive purposes.

=Reproductive=

//Reproductive purposes// include making identical copies of cells or organisms. Dolly is a prime example of reproductive cloning (somatic cell nuclear transfer) because she was an exact genetic copy of another sheep. Dolly was created by extracting the DNA of an egg cell and inserting the DNA of an adult cell from the original sheep. This egg and DNA hybrid was then stimulated to divide until in developed into a blastocyst. It was then implanted into a surrogate mother. The outcome was an identical copy of the original donor, thence called Dolly.

To make Dolly, researchers isolated a somatic cell from an adult female sheep. Next, they transferred the nucleus from that cell to an egg cell through a microscopic glass tube from which the nucleus had been removed. After a couple of changes, the egg cell, with its new nucleus, was behaving just like a freshly fertilized zygote. It developed into an embryo, which was implanted into a surrogate mother and carried to term. Dolly was an exact genetic replica of the adult female sheep that donated the somatic cell nucleus to the egg. She was the first-ever mammal to be cloned from an adult somatic cell.



=Therapeutic=

Therapeutic nuclear transfer is the same process as reproductive cloning only it is used to produce certain types of cells that can be used to help people- in this case stem cells. For instance, a blood, muscle, or skin cell can have its nucleus extracted. A nucleus that contains the genes for reprogramming the cell back to a stem cell can then be inserted. The hybrid then develops into an early-stage embryo from which pluripotent stem cells can be extracted. Of course, even though there has been progress with animals, attempts to produce human embryonic stem cells have remained unsuccessful.

=Future Uses=

The major problem of using embryonic stem cells in cell therapies is that they could be rejected by the patients immune system, which would see them as foreign. Scientists are working on a way to make "custom" embryonic cells through nuclear transfer that match the patient's immunolic profile. This method would involve removing the dna from the patient's own muscle and skin cell and inserting it into an egg cell. The new cell would then be coaxed into reverting back to a stem cell. These stem cells could then be used to generate any cell or tissue because it would now match the patient's immunological profile.

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