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Published online 14 November 2007 | Nature | doi:10.1038/news.2007.245
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Cloned monkey stem cells produced
Stem cells extracted from cloned primate embryos.
Researchers have for the first time created cloned primate embryos and used them to make embryonic stem-cell lines. The achievement has led to speculation about when similar success in humans might open up the door for therapeutic cloning.
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I'm fairly sure that the scientists obtained the "stem cell" by using a toti-potent egg cell, as stated in the article.
I am talking about the skin cell Craig.
In Somatic Cell Nuclear Transfer (SCNT) the donor cell does not need to be a stem cell, it can be a cell obtained from a skin biopsy or other tissue. The point of the paper is that a somatic cell (i.e., the fibroblast cells obtained from a skin biopsy) can be reprogrammed by the oocyte such that an embryo is obtained. Stem cells were then derived from that embryo. Perhaps you should read the paper thoroughly before making disparaging remarks.
Reprogramming of a differentiated cell nucleus by somatic cell nuclear transplantation is an inefficient process. Following nuclear transfer, the donor nucleus often fails to express early embryonic genes and establish a normal embryonic pattern of chromatin modifications. These defects correlate with the low number of cloned embryos able to produce embryonic stem cells or develop into adult animals. Here, we show that the differentiation and methylation state of the donor cell influence the efficiency of genomic reprogramming. First, neural stem cells, when used as donors for nuclear transplantation, produce embryonic stem cells at a higher efficiency than blastocysts derived from terminally differentiated neuronal donor cells, demonstrating a correlation between the state of differentiation and cloning efficiency. Second, using a hypomorphic allele of DNA methyltransferase-1, we found that global hypomethylation of a differentiated cell genome improved cloning efficiency. BTW, I offered to give a DNA test to Oregon Primate Center and they refused. If they were honest they would have no reason to refuse. It's like an athlete refusing to take a steroid test.
Inefficient does not mean impossible. It is certainly true that some cell types and some cell lines are more efficient at producing viable clones than others. Never-the-less, live animals can and have been produced from fibroblasts obtained from skin biopsies. Certainly it is easier to obtain a skin biopsy than neural stem cells, don't you agree? I believe I read somewhere that Nature arranged for the confirmation to be performed by another group. Perhaps someone from Nature can confirmed that. I know both teams and have faith in their reports. But after Hwang's lab's fiasco, I can understand some of your skepticism.
I sent an email in Febuary 2004 to Hwang saying that I didn't believe his claim that he cloned stem cells. There was no response and the reason there was no response was because nearly two years later he was revealed as a fraud. Inefficeint to me does mean impossible because that term means something doesn't work at all. An extraordinary claim requires an extraordinary evidence, esp in this case. If someone claimed to invent a time machine I'd be very skeptical as we naturally should.
These people in Oregon refused to let me take a DNA test that I offered them. It is no different then the email I sent to Hwang woo Suk back in Febuary of 2004 telling him that he commited fraud and him refusing to reply.
Congratulations to Dr. Mitalipov and team for doing what some had said was impossible. How did their enucleation technique, which they credit for their breakthrough, differ from that previously reported in Nature Biotechnology 18:223, 2000?
Congratulations to Dr. Mitalipov and team for doing what some had said was impossible. How did their enucleation technique, which they credit for their breakthrough, differ from that previously reported in Nature Biotechnology 18:223, 2000?
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So why should we or the authors trust Mike Allen to do DNA testing? Surely an impartial third party would be better than an obviously bias point of view?
David, I am the least unbiased person because I don't even know the Oegon scientists personally. Alan Trounson knows the Oregon researchers personally, in fact he was the chariman of the June meeting.
David, I am the least unbiased person because I don't even know the Oregon scientists personally. Alan Trounson knows the Oregon researchers personally, in fact he was the chairman of the June meeting.
David Zeelenberg, I sent an email to Hwang woo Suk back in Feburary 2004 saying that he created parthenotes and claimed that they were clones. For a near full two years everyone I told this to said that I was biased and I didn't have the credentials to dispute Hwang's cloning work and it turned out that I was right. Sat, 14 Feb 2004 14:02:26 -0800 (PST) From: "Mike Allen" <dude58674@yahoo.com> Add to Address Book Add Mobile Alert Subject: Hi To: hwangws@snu.ac.kr Your cloning report is nothing more then a brilliant fraud. You have created parthenegensis and instead lied by saying they are cloned embryo's. Of course you say DNA tests mean they came from the same donors
Sat, 14 Feb 2004 14:02:26 -0800 (PST) From: "Mike Allen" <dude58674@yahoo.com> Add to Address Book Add Mobile Alert Subject: Hi To: hwangws@snu.ac.kr Your cloning report is nothing more then a brilliant fraud. You have created parthenegensis and instead lied by saying they are cloned embryo's. Of course you say DNA tests mean they came from the same donors
David, why don't you offer the Oregon Primary Reserach Center a DNA test and tell me how it goes? Tell who you spoke to so then I can ask them the same question.
Maybe the moderator could remove all of Mike Allen's comments and if possible block him from making any further ones? He's not exactly adding anything constructive here. Please don't reply to this comment Mike.
Maja, the truth hurts and you can't deal with it. That is why you want my posts blocked. You make no efort to refute anything I have stated. You're the kind of person who if they ran a country would eliminate free speech.
Maja, the truth hurts and you can't deal with it. That is why you want my posts blocked. You make no effort to refute anything I have stated. You're the kind of person who if they ran a country would eliminate free speech.
Maja, YOU hate real science as real science praises dissent. Science is supposed to be open discussion.
I think people are totally right to have their own opinions (I guess that is what these comments are for) but I don’t think people should be pushing ones opinion on to others… or make personal comments… I am sure the editors would have done enough checks to convince that this research is true but all we can do is to wait and see if this research is true or not. I am sure the researches cannot be giving OK for the DNA checks to everyone that ask for them. So we have to rely on the check done by nature. Otherwise there is no point in publishing controversial papers!
What interests me most is how the "hybrid" cell is able to divide and maintain pleuripotency given that the chromatin code is inherited from a differentiated cell. Could anyone point me in the direction of an explanation?
Hello - this is the moderator. We have had a few inappropriate posts in this thread so I have changed the posting rules. All comments will now be viewed by a moderator before publication. You may experience a delay before your comment appears. Thanks.
So appropiate posts have to agree with what everyone says? That's a real open discussion.
You at Nature are empowered to ensure an honest system of peer review. I am not anti-science as science is essential to our well being. What we should all strive for is truth. Without truth there is no progress. If all there is are scientists who put fame and fortune above truth, then we as a society have a problem. We must also ensure that science is open and if it isn't it becomes nothing more then a propaganda machine. You at Nature are empowered to ensure truth through the peer review process, so do it.
One of the most interesting issues of nuclear cloning is the question of genomic reprogramming, i.e. the question whether successful cloning requires the resetting of epigenetic modifications which are characteristic of the adult donor nucleus. The full term development of other species such as mice, sheep, goats, cows and pigs mice has been achieved through the transfer of somatic cell nuclei into enucleated oocytes. Despite these successes, mammalian cloning remains an inefficient process, with a preponderance of reconstructed embryos failing at early to midgestation stages of development. The small percentage of conceptuses that survive to term are characterized by a high mortality rate and frequently display grossly increased placental and birth weights. Jeeri Reddy - 16 Nov, 2007
Congratulations to Dr. Mitalipov and Team members Dr. Jeeri R. Reddy JN International Medical Corporation
Lets hope we get a step closer to human cloning this way. Good luck!
Lets hope we get a step closer to human cloning. good luck!
It appears to me that the “success†of obtaining just 2 stem cell lines with the use of 304 eggs is not a success at all but largely a same level of failure as experienced in the previous cloning efforts. Thus, the low-efficiency “sound barrier†for cloning – be it called reproductive cloning or therapeutic cloning – is still largely intact. What all the cloners doing right now is just like a surgeon performing surgery without knowing of or paying attention to the anatomy. And thus the survival and healing of the patients is largely left to the Nature. Then what science is really contained in the cloning? Cloning experts have praised this “success†of cloning monkey as a milestone and the authors of this study have claimed their “success†as a “proof-of-concept†or “proof-of-principle†for therapeutic cloning in primates which include human beings. However, as far as I see, the concept or principle of nuclear transfer cloning has been proved many times but as a low-efficiency and high-risk technique that should never be used on human until it the efficiency reaches acceptable never and side-effects are eliminated. In addition, I have not seen any truly successful therapeutic use of any of the “all-purpose†stem cells cloned so far. Thus, the over-selling of this still extremely low-efficiency cloning technique for untested therapeutic value is not raising hopes but hypes which may be necessary for “regenerative medicine†but will do no good to human society. (Abstracted from “Higher scientific and ethical standard for reporting therapeutic cloning†in Top Watch 2: 90-93, 2007; complete version free at http://im1.biz)
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This work sounds really brilliant. I do believe all comment is constructive. But I would suggest Mr. Allen post something really useful and less aggressive...