Cloned Human Embryo Created From Skin Cells (1/23/2008)
Stemagen, a privately held embryonic stem cell research company, announced January 17 it has become the first in the world to create, and meticulously document, a cloned human embryo using somatic cell nuclear transfer (SCNT).
|(1PN-SCNT) The first sign of successful cloning. The first indication that cloning has been successful is the observation of a single pronucleus, seen here, which contains the donated material from the donor skin cell. (Credit: Image courtesy of Stemagen)|
Stemagen CEO Samuel H. Wood, M.D., Ph.D., a co-author of the publication and a donor of the cells from which the embryos were cloned, terms this achievement "a critical milestone in the development of patient-specific embryonic stem cells for human therapeutic use, potentially including developing treatments for Parkinson's, Alzheimer's and other degenerative diseases." Stemagen's research is exhaustively detailed in a paper published in the January 17 issue of the peer-reviewed scientific journal Stem Cells.
"This is not merely a technical improvement on previous research in this area," said Andrew French, Ph.D., lead author on the paper, "Development of Human Cloned Blastocysts Following Somatic Cell Nuclear Transfer (SCNT) with Adult Fibroblasts."
"No other scientific group has documented the cloning of an adult human cell, much less been able to grow it to the blastocyst stage, the stage at which it is the adult donor cell that is driving embryonic development, the stage that yields the cells (the inner cell mass) from which embryonic stem cell lines are made," said French, who is Stemagen's Chief Scientific Officer.
Five blastocysts were developed from 25 donated mature oocytes. Three were confirmed to be clones based on DNA fingerprinting demonstrating the presence of the skin cell donor DNA in the blastocyst, while one was further confirmed to be a clone by an additional mitochondrial DNA (mtDNA) analysis which revealed the presence of oocyte donor mtDNA without any oocyte donor nuclear DNA. For technical reasons, the genetic material in the remaining two blastocysts did not amplify to the extent required for analysis, and so while it is likely they were clones, the evidence required to claim that with certainty was not present. Thus, in this study, cloned blastocysts were successfully created from approximately 10% of all mature donated oocytes, an unexpectedly high rate given past research in this field.
The oocytes used in this study were donated by egg donors and intended parents undergoing egg donation cycles for reproductive purposes at the Reproductive Sciences Center in La Jolla, a leading fertility center specializing in egg donation and other advanced assisted reproductive technologies. Stemagen and the Reproductive Sciences Center worked closely, over an extended period of time, with a leading independent Institutional Review Board (IRB) to develop procedures ensuring that all parties received comprehensive informed consent and that procedures were in place to protect their confidentiality in the process.
All research procedures, including the culturing of the skin cells (fibroblasts) were performed under clinical laboratory conditions in close cooperation with the Assisted Reproductive Technologies (ART) Laboratory of the Reproductive Sciences Center, directed by Catharine Adams, Ph.D. French notes, "An important reason for the success of our SCNT procedures depended on the close coordination between our laboratory personnel and fertility center laboratory staff. Timing is a critical element in maximizing the probability of success in this type of procedure."
Wood points out that this research was exhaustively scrutinized by some of the world's most respected scientists and underwent an exceptionally rigorous process of verification, "This achievement was so critical to our field, we felt we should spare no effort in the process of establishing the validity of our work."
DNA fingerprinting is the scientifically accepted method for determining if an embryo is a true clone. According to French, "All samples were subjected to this type of analysis to determine their true genetic makeup."
For that, the company turned to Genesis Genetics, a recognized worldwide leader in the field of reproductive embryonic analysis.
Note: This story has been adapted from a news release issued by Stemagen