Slashdot Mirror
Skin Cells Turned Embryonic
anik315 writes "Nature is reporting a major breakthrough in embryonic stem cell research. A straightforward procedure using mouse fibroblasts harvested from the skin can be used to produce pluripotent stem cells that can potentially become any other cell in the body. Not only can Yamanaka's method use the most basic cells, it can be accomplished with simple lab techniques. Possible applications of this breakthrough are to check molecular changes in cells as certain conditions develop. Stem cells produced using this procedure, however, can not be used safely to make genetically matched cells for transplant."
Actual papers for those interested (it was published simultaneously by three groups): (Nature probably requires subscriptions, the first one is free access)
e xt?uid=PIIS1934590907000203
t /full/nature05934.html
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Nimet Maherali, Rupa Sridharan, Wei Xie, Jochen Utikal, Sarah Eminli, Katrin Arnold, Matthias Stadtfeld, Robin Yachechko, Jason Tchieu, Rudolf Jaenisch, Kathrin Plath, and Konrad Hochedlinger
http://www.cellstemcell.com/content/article/fullt
Keisuke Okita, Tomoko Ichisaka & Shinya Yamanaka
http://www.nature.com/nature/journal/vaop/ncurren
Marius Wernig, Alexander Meissner, Ruth Foreman, Tobias Brambrink, Manching Ku, Konrad Hochedlinger, Bradley E. Bernstein & Rudolf Jaenisch
http://www.nature.com/nature/journal/vaop/ncurren
"The four transcription factors used by Yamanaka reprogramme cells inconsistently and inefficiently, so that less than 0.1% of the million cells in a simple skin biopsy will be fully reprogrammed."
As noted, the major problem is not just the inconsistency, but the locating of the modified cells.
However, unlike many other slashdot articles, this is is in a peer-reviewed journal, it is based on a technique which has been run for a while and altered based upon other followup work, and it might prove a useful addition for labs to do research, while of limited use in therapeutics.
But that also depends on cost. People forget that a successful research lab has got to get costs per experiment down - if it costs me $20 per sample and I have a plate of samples, I'll go broke trying to run any sizeable research of any note, especially that with significant data that can answer more than 2 basic questions of statistical significance.
-- Tigger warning: This post may contain tiggers! --
I love the irony of your post. I wish I believed it was intentional.
Simplicity. Protocol. Reproducibility.
Labs that experiment on mice use specific inbred genetic lines that are widely available with limited genetic diversity. This limits the amount of experimental error that can be attributed to the variations in the traits of the animals. It also means that other labs attempting to reproduce the same results will have a greater chance of success because they'll be starting with an organism that genetically is nearly identical to the ones used elsewhere.
See Model Organism.
"With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea...."
RFC 1925
Because then they could be left with an ethical quandry about what to do with any unexpected human embryos that might be produced from the experiments.
File under 'M' for 'Manic ranting'
A person's skin DNA is the same as the rest of their DNA
Technically it's not. Once a stem cell starts to differentiate, you see different patterns of epigenetic changes that alter which genes are actively expressed and which are silent. It's part of the reason why you don't have eyeball proteins expressed by your feet. In general, we've found that once you start initiating a cascade where a stem cell starts differentiating into something else, it's difficult to go backwards and "undo" the changes.
Actually, the fetus will naturally miscarry a significant percentage of the time, with that percentage getting fairly high depending on various factors. Is a 45 year old women who gets pregnant guilty of reckless endangerment?
http://en.wikipedia.org/wiki/Miscarriage#Prevalen
Prospective studies using very sensitive early pregnancy tests have found that 25% of pregnancies are miscarried by the sixth week LMP (since the woman's Last Menstrual Period).[13][14] The risk of miscarriage decreases sharply after the 8th week, i.e. when the fetal stage begins.[15] Clinical miscarriages (those occurring after the sixth week LMP) occur in 8% of pregnancies.[14]
The prevalence of miscarriage increases considerably with age of the parents. Pregnancies from men younger than twenty-five years are 40% less likely to end in miscarriage than pregnancies from men 25-29 years. Pregnancies from men older than forty years are 60% more like to end in miscarriage than the 25-29 year age group.[16] The increased risk of miscarriage in pregnancies from older men is mainly seen in the first trimester.[17] In women, by the age of forty-five, 75% of pregnancies may end in miscarriage.[18]