Faulty Reprogramming Likely Culprit behind Cloning Failures, Review Finds

CAMBRIDGE, Mass.  — Faulty reprogramming of the genome is most likely the culprit behind abnormalities common in cloned animals, according to a review article in the July 17 issue of the New England Journal of Medicine. The article, co-authored by Rudolf Jaenisch, a Member scientist at Whitehead Institute for Biomedical Research, and Konrad Hochedlinger, a postdoctoral associate in the Jaenisch lab, is one of four in the journal on the topic of cloning and stem cell research.

A common denominator of both cloning and stem cell research is nuclear transfer, the process by which the genetic information from one cell is transplanted into an unfertilized egg, whose DNA has been removed. When placed in a Petri dish, this egg develops into a line of stem cells; when placed in the uterus of a female, it eventually can develop into a fetus. The “abnormalities associated with reproductive cloning are not expected to impede the use of this technique for therapy,” the authors write, referring to, among other applications, certain types of gene therapy for which stem cells might be ideal. The researchers also hint at a future in which scientists may be able to create embryonic stem cells directly from adult cells.

Whitehead Institute Visiting Scientist George Daley also authored a commentary for the issue, a piece that considers the legislative quagmire he says has come to characterize the politics of stem cell research, including a bill pending in the U.S. Senate that would criminalize the very process of nuclear transfer. After summarizing both federal and state attempts to construct a coherent public policy, Daley warns that, “Legislation that unduly restricts the pursuit of nuclear-transfer studies will cripple innovation.”

Two other articles on the subject appear in this week’s issue, including an editorial by NEJM editor-in-chief Jeffrey Drazen, and a review article by Nadia Rosenthal of the European Molecular Biology Laboratory in Rome, Italy, that surveys current research with adult stem cells.

Citation

Hochedlinger, K., & Jaenisch, R. (2003). Nuclear transplantation, embryonic stem cells, and the potential for cell therapy. New England Journal of Medicine, 349(3), 275-286.