In mice, Daley and colleagues have shown that stem cells derived from the nuclear transfer of cells to make embryos -- the technique described in Mitalipov's paper -- were indeed closer to natural embryo stem cells than induced pluripotent stem cells.
Earlier this week a team in the U.S. led by Shoukhrat Mitalipov of the Oregon National Primate Research Center, announced they had created the first cloned monkey embryo and extracted stem cells from it.
These cells are then cloned to create an embryo, and then embryonic stem cells that are genetically inclined to discover this disease.
They used stem cells from a human embryo, which are capable of becoming any other type of cell in the human body from nerve to skin, muscle to kidney.
However, when stem cells are removed, the embryo is destroyed -- which has made this one of the most controversial medical research fields in the past decade.
Embryonic stems research is inherently controversial because in order to use the stem cells for science, the embryo, which is a collection of cells that could develop into a fully formed human, is destroyed, even though embryos in these procedures are left over from in vitro fertilization.
After all, to obtain these stem cells, you must destroy a human embryo.
When the embryo is 4 or 5 days old, scientists extract the stem cells and put them in a petri dish.
Stem cells are more potent and in far richer supply in embryos, but culling embryonic stem cells requires the ethically tricky step of destroying an embryo to get them.
The success also provides encouragement that useable stem cells can be found from other sources apart from the human embryo, which remains controversial.
With the removal of these stem cells -- of which there may be about 30 -- the embryo is destroyed.
' Another idea is to take a single cell from a developing embryo and then let that develop and see if those couldn't be used to derive stem cells.
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