Lead Into Gold: Scientists Wax Enthusiastically
The power of the IPSCs is becoming so evident that, like Ian Wilmut before them, many scientists are joining the field. From a story in Nature Reports Stem Cells: The fact that making iPS cells does not pose the technical and ethical challenges of working with eggs or embryos is drawing large numbers of researchers into the field and speeding up reprogramming research. "This is definitely the hot thing right now," says Melina Fan, executive director of Addgene, the Cambridge, Massachusetts–based nonprofit repository that distributes both Thomson's and Yamanaka's viral vectors for the cell-reprogramming genes. As of 17 April, she says, there have been 704 requests from 178 labs at 142 institutions for Thomson's vectors; 514 requests from 131 labs at 113 institutions for Yamanaka's human iPS cell vectors; and over 1,500 requests from 232 labs at 215 institutions for Yamanaka's murine iPS cell vectors. The statistics speak for themselves. Although the Thomson and Yamanaka stem cell plasmids make up only 0.2% of Addgene's total collection, they've accounted for over 10% of Addgene's total plasmid requests since the beginning of 2008, Fan says.
Apparently, the IPSCs offer what scientists hoped for with ES cells: "Biologically there's no difference" between murine iPS and ES cells, says Jaenisch. Both can generate all the tissues in a mouse. Human iPS cells have not been as rigorously demonstrated to be quasi-equivalent to ES cells, and they won't be, because doing so would require generating human babies or foetuses.
Unless scientists want to pursue Brave New World agendas such as fetal farming, it should mark the death knell for human cloning research: No one doubts that iPS cells will eventually be generated from the cells of individuals with known medical history. That was the main advantage claimed for somatic cell nuclear transfer, a technically and ethically challenging procedure that has yet to be achieved in humans. For generating person-matched cells, iPS cells may be not only easier to use but perhaps superior, as they would share both nuclear and mitochondrial DNA with the original patient, whereas cells derived by somatic cell nuclear transfer carry only the same nuclear DNA.
Remember, folks, this is from "the scientists." A new day has indeed dawned.
posted by Wesley J. Smith @ 9:37 PM
5 Comments
5 Comments:
"Human iPS cells have not been as rigorously demonstrated to be quasi-equivalent to ES cells, and they won't be, because doing so would require generating human babies or foetuses."
I don't understand that sentence. Is the point that the only way to rigorously demonstrate this _is_ to generate human embryos? Because one of the cell types they have to generate in such a demonstration is functional gamete cells?
Lydia: I think this is what is meant: Pluripotency hasn't been achieved in the Petri dish. Only in living organisms. Thus, one test of pluripotency is to create cloned mice using the stem cells, which I mentioned in an earlier post, that involves essentially destroying the animal embryo but keeping its "shell" and then introducing the stem cells, which, in essence create a new embryo with a new genetic makeup. (This isn't SCNT which only transfers a nucleus into an egg.) If the cells are pluripotent, they will create the whole animal during gestation. The embryo is implanted and gestated to birth. The mouse is euthanized and its tissues tested to see if all the tissues have the markers of the new genetic (from stem cells) entity. Can't do that with humans, at least not yet.
You sound like a herd of ostriches trying to give the lay public the "mushroom treatment"; that is 'keep them in the dark and feed them fecal matter'.
Human cloning from skin cells is not only possible, but probable, given the vast amount of private funding available for such functions. Haven't you ever heard of HHMRI and other private 'foundations'?
R John,
Where have you been the last 4 or 5 months? SHS doesn't do mushrooms, so you'll have to go elsewhere to find some.
SHS announced that human cloning was reported to have occured with researchers in San Diego and that one of the two clones was a clone of one of the researchers. Of course in the wake of the new direct reprogramming method of getting pluripotent stem cells (iPS cells) it generated a yawn-a one day story, though it is very scary to me. The clones were killed instead of trying to create a stem cell line out of those two little human beings who were still embryos. Of course it's probable, but hopefully the new technique of direct reprogramming will make researchers go away and protect and prevent the tampering of human life.
rJohn: Crudity is not needed or appreciated here. Thank you.
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