Possible new source of embryo stem cells

A team of British researchers announced last week that they may have found a new source of embryonic stem cells. John Gurdon, from the Wellcome Cancer Research Institute at Cambridge University, reported in the Proceedings of the National Academy of Sciences that he and his colleagues have found that cloned frog embryos that were found to be defective could still produce useful stem cells.

The research team believe that their research shows why it might be 'premature' to ban cloning or stem cell research. If defective human embryos - ones that could not or would not be used to create children - could also yield stem cells, it 'might be a quite interesting way around the problem' that using potentially viable embryos causes, said Gurdon.

It is thought to be common practice that 'abnormal' human embryos, created during IVF treatments, are 'thrown away'. But the researchers found that normal stem cells could be derived from even abnormal frog embryos. The scientists took frog embryos that would not normally survive and grow, and that had been genetically altered to carry a fluorescent green protein. Stem cells were taken from these embryos and grafted into 'normal' frog embryos. These were allowed to grow into tadpoles, which were later found to still be carrying green cells, showing that the stem cells had survived and propagated.

The team believe that if the same process worked in humans, many of the ethical objections to the use of human embryonic stem cells would be countered. Gurdon commented that 'the objection in America to their use is that these embryos are potential human beings. My argument is they are not potential human beings if they are destined to die'.