>It’s (she’s) an embryo. What part of “I’m all for stem cell research, but don’t kill a human embryo” don’t they get?
Harvard’s George Q. Daley is in the news again. This time his research group has produced parthenogenetic mouse embryos, that were used to harvest stem cells. The original article has been published online (Free abstract) before going to print, in Science Express, a feature of the journal, Science. Another well-written review from a slightly different is available online at “ThisisLondon.com,” a feature of the UK’s Evening Standard. Here’s another from Scientific American. Frequent mention of “virgin birth” in the articles is telling.
The method used chemical treatments to prompt the egg to develop into an embryo, a process known as parthenogenesis, and then extracted stem cells from it.
The embryo could not have otherwise developed into a baby mouse, so, even in humans, the strategy is unlikely to raise as serious ethical objections as other methods that destroy a viable human embryo.
I don’t think so. The only reason that the “embryo could not have otherwise developed into a baby mouse” is because the researchers intended to destroy it in order to harvest those stem cells. If the embryo had been human, the creation of an embryo in such a situation (that carries a high level of risk for the embryo) can not be ethical.
Parthenogenetic mouse embryos have been developed before, as the Boston Globe artical notes. In 2004, an article in Nature (free abstract online) reported that one of these embryos was implanted and grew to birth, grew to adulthood, became pregnant herself and gave birth to normal mouse babies. This was one of 10 who survived nearly to birth of 23 embryos that were implanted.
Why shouldn’t we assume that if the hurdles of parthenogenesis in humans is overcome that the problem with implantation and gestation to whatever stage of developement will seem useful to researchers?
At least, this Boston Globe article doesn’t use the term “virgin birth” and it is more honest than some mass media stories on cloning and destructive embryonic stem cell production. The author, Cary Goldberg calls the embryos “embryos” and mentions the worries about tumor formation and other abnormalities of stem cells derived from embryomnic stem cells, as well as the risk of tumor production:
The immediate benefit of the technique is for researchers; it still has many hurdles to overcome before it will be clear whether it is safe for use in humans, said George Q. Daley of Children’s Hospital Boston, senior author of the paper published online in the journal Science. There is concern, for example, that such cells could become cancerous.
But, he said, the technique may be closer to working in humans than somatic cell nuclear transfer, the conventional approach in animals for generating customized embryonic stem cells.
In that method, a nucleus from a regular cell such as a skin cell is inserted into an egg and induced to develop.
Also known as therapeutic cloning, it is highly inefficient in animals and has yet to be mastered in humans, though two Harvard teams, including Daley’s, are trying.
“This is a much more workable approach to generating patient-specific and tissue-matched embryonic stem cells,” Daley said. “But the trade-off is that these cells may not prove to be normal and functional.”
If the egg technique works in humans, women would be their own immediate beneficiaries, but the effects could be wider, Daley said. It could also lead to the broader production of stem cells that have only half the usual set of immune system genes — perhaps even whole banks of such cells — and that therefore would be compatible with many patients who need to grow new tissue.
Professor Daley needs to Google umbilical cord blood cells.