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embryonic stem cells and nuclear reprogramming

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Background: Embryonic stem cells

  • Embryonic stem cells are cells that can grow for an unlimited time in the laboratory and which can develop into any type of body cell, making them ideal for research into treatments of degenerative diseases such as Parkinson’s and Motor Neurone Disease.
  • Such diseases could be treated by implanting stem cells, which could then grow and repair damaged tissues. Alternatively they could be used to study the mechanisms that cause the disease to develop new treatments that don’t involve stem cells.
  • To use embryonic stem cells directly as a treatment for disease could cause problems involving immune rejection (much like rejection of organs during transplantation unless the right match is found). So researchers are keen to create embryonic stem cells that are derived from the patients own cells, which would overcome the problem of immune rejection.
  • Patient specific stem cells could be created by therapeutic cloning, as outlined below.
  • Alternatively, a new technique of cell nuclear reprogramming (see below) has been outlined in recent research papers which potentially provides an alternative source of stem cells for disease research.



Therapeutic cloning and nuclear reprogramming


Therapeutic cloning

  • Therapeutic cloning involves a technique called somatic cell nuclear transfer, in which the nucleus of a body cell is removed and inserted into an egg cell which has had its nucleus removed
  • The resultant cell is then induced to divide, usually by applying an electric shock, to form an embryo which is a genetic copy (i.e. a clone) of the original body cell
  • Embryonic stem cells might then be removed from the cloned embryo and grown in the laboratory, and used to study diseases such as Parkinson’s and Motor Neurone Disease.

therapeutic cloning


Nuclear reprogramming

  • In the new technique, fibroblast cells isolated from skin tissue are modified by inserting four genes which cause the cells to be ‘reprogrammed’ into cells that are very similar to embryonic stem cells
  • The resulting embryonic stem cell-like cells have the potential to form different tissues in the body. It is possible that these cells could provide an alternative source of stem cells to be used to study and perhaps treat disease.

nuclear reprogramming


This is a fact sheet issued by the Science Media Centre to provide background information on science topics relevant to breaking news stories. This is not intended as the ‘last word’ on a subject, but rather a summary of the basics and a pointer towards sources of more detailed information. These can be read as supplements to our roundups and/or briefings.


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