Human ' Cloning ' makes Embryonic stem cells
5 October 2011 Last updated at 18:04 GMT Share this page
Human 'cloning' makes embryonic stem cells
By James Gallagher Health reporter, BBC News
Lead scientist Dr Dieter Egli: "Research gives hope for making cells to cure human disease in the future"
A form of cloning has been used to create personalised embryonic stem cells in humans, say researchers.
Genetic material was taken from an adult skin cell and transferred into a human egg. This was grown to produce an early embryo.
Stem cells have huge potential in medicine as they can transform into any other cell type in the body.
However, the stem cells formed contained chromosomes from both the adult and the egg cells.
The technique used - somatic cell nuclear transfer - shot to fame in 1997 when Dolly the sheep, the first mammal to be cloned from an adult cell, was unveiled to the world.
A South Korean scientist, Hwang Woo-suk, had claimed to have created stem cells from cloned human embryos, but was found to have faked the evidence
The lead researcher at the New York Stem Cell Foundation Laboratory, Dr Dieter Egli, said there was "a great question mark" about whether the cloning technique could be reliably used in humans.
Dolly the sheep
He said other "groups had tried before, but failed".
Writing in the journal Nature, he said his group had also failed using traditional techniques.
When they removed the genetic material from the egg and replaced it with the chromosomes from a skin cell, the egg divided but failed to go past the 6-12 cell stage.
However, when they left the egg's own genetic material in place and added the skin chromosomes, the egg developed. It reached the blastocyst stage, which can contain up to 100 cells and is the usual source of embryonic stem cells.
Eggs and sperm both have one set of chromosomes, which combined means adults have two copies of each chromosome.
In this technique the two adult copies are added to the single copy in the egg meaning a total of three, which can be problematic.
Last edited by ~Maliha~; 06-04-2012 at 06:50 PM.