Human to Animal Cloning Has Problems
The shortage of human donor eggs has led to efforts to substitute animal oocytes, but there are problems...
Feb 20, 2009
This press release is an announcement submitted by Mary Ann Liebert, Inc., and EurekAlert, and was not written by Diabetes Health.
We recently interviewed Dr. José Oberholzer, M.D., who works with stem cells at the Chicago Diabetes Project. Click here to read what he said about animal-to-human clones.
Somatic cell nuclear transfer (SCNT) has been considered a promising way to generate human stem cells for therapeutic applications for more than a decade. The shortage of human donor eggs has led to efforts to substitute animal oocytes. However, a new study published online in Cloning and Stem Cells, a peer-reviewed journal published by Mary Ann Liebert, Inc., demonstrates that animal oocytes lack the capacity to fully reprogram adult human cells. (The paper is available free online at www.liebertpub.
Robert Lanza, M.D., and colleagues from Advanced Cell Technology (Worcester, MA), Wake Forest University School of Medicine (Winston Salem, NC), Reproductive Medicine Associates of New Jersey (Morristown)
The ability to reprogram human cells using oocytes would enable the production of patient-specific stem cells that could then be differentiated to become any type of somatic cell and used for cell or tissue repair or placement therapy. This extensive reprogramming requires that the oocyte turn on, or up-regulate, a large number of genes in the donor nucleus.
Although previous reports have documented the formation of cloned embryos using both human and animal eggs, to date there have been no data indicating to what extent the donor human DNA was reprogrammed. Lanza, et al., show for the first time that human oocytes have the capacity to change these patterns of gene expression and that interspecies (human-to-animal) cloning does not produce the same results.
Although the human-bovine and human-rabbit clones looked similar to the human-human embryos, the human-animal hybrids did not exhibit the changes in gene expression seen in the human-human clones and normal embryos. Specifically, they did not achieve up-regulation of critical pluripotency-
"This very important paper suggests that livestock oocytes are extremely unlikely to be suitable as recipients for use in human nuclear transfer. This is very disappointing because it would mean that production of patient-specific stem cells by this means would be impracticable,
Source: Mary Ann Liebert, Inc., and EurekAlert
http://www.diabetes
«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»«¤»¥«¤»§«¤»¥«¤»§«¤»¥«
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
StemCells subscribers may also be interested in these sites:
Children's Neurobiological Solutions
http://www.CNSfoundation.org/
Cord Blood Registry
http://www.CordBlood.com/at.cgi?a=150123
The CNS Healing Group
http://groups.yahoo.com/group/CNS_Healing
____________________________________________
«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»«¤»¥«¤»§«¤»¥«¤»§«¤»¥«
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch format to Traditional
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe
No comments:
Post a Comment