A team of Oregon Health and Science University researchers has succeeded in creating rhesus monkeys who have in their cells the genetic heritage of six different 'parent' monkeys. These lab monkeys - called chimera after a fire-breathing character in Greek mythology made up of parts from different animals - were the result of experiments designed to gain more understanding into stem cells that might be used to create human tissue in the future.
Researchers led by Shoukhrat Mitalipov, a scientist at the Oregon National Primate Research Center, were focused on how natural stem cells from early embryos differed from cultured embryonic stem cells which are more readily available to scientists. In a variation of cloning procedures, they were able to inject stem cells into monkey embryos to produce chimera, but the procedure only worked when the cells were fresh, not cultured stem cells.
Similar cloning studies had previously been done in rats, but not in primates which more closely resemble humans, Mitalipov says.
Next, Mitalipov says, is learning why mature stem cells don't reproduce tissue in the ways fresh, embryonic cells do.
'Now we know the (stem) cell lines we have on board are not the gold standard,' says Mitalipov.
The experiments were reported today in the scientific journal Cell.