From the 10,000 foot perspective adult stem cells have always seemed to be far more interesting than embryonic stem cells since everyone has them. The far future fantasy scenario of being able to grow replacement parts for injured people from the tattered remnants of their bodies seemed to be the most desirable and effective goal. So, I am always happy to see progress.

The simple recipe scientists earlier discovered for making adult stem cells behave like embryonic-like stem cells just got even simpler.A new report in the February 6th issue of the journal Cell, a Cell Press publication, shows for the first time that neural stem cells taken from adult mice can take on the characteristics of embryonic stem cells with the addition of a single transcription factor. Transcription factors are genes that control the activity of other genes.

The discovery follows a 2006 report also in the journal Cell that showed that the introduction of four ingredients could transform differentiated cells taken from adult mice into "induced pluripotent stem cells" (iPS) with the physical, growth, and genetic characteristics typical of embryonic stem cells (http://www.eurekalert.org/pub_releases/2006-08/cp-wff080906.php). Pluripotent refers to the ability to differentiate into most other cell types. The same recipe was later shown to work with human skin cells as well (http://www.eurekalert.org/pub_releases/2007-11/cp-srt111307.php). . .

"Now we've come down to just one that is sufficient. In terms of the biology, it's really quite amazing."

The discovery sheds light on centuries-old questions about what distinguishes the embryonic stem cells that give rise to egg and sperm from other body cells, Schöler said. It might also have implications for the use of reprogrammed stem cells for replacing cells lost to disease or injury.

We seem to be getting ever closer to the old SF notion of scooping up injured people, slapping them in the auto-doc, and waiting while new parts are grown in situ from whatever cells are available. Now what we need is progress on mind backup and storage so that people can be rebooted from a previous version of themselves when their brains are ruined and need to be replaced. Perhaps sample cells should be archived as well so that they can be reinstantiated even if the host body is completely lost.

If we could do that, would we want to? If we could regrow bodies in this way would we want to make improvements while we were at it? If improvements could be made would we require and wait for injury to do the upgrades? What and how we are would be subject to the whims of fashion.