Scientists Confront Cloning Challenges

摘要

San Francisco-Nuclear cloning holds great promise for curing or alleviating a number of diseases and conditions. Apart from various ethical considerations, the technique has a number of technical hurdles to clear before it has a chance of making its way into the clinic.Nuclear cloning (also called nuclear transfer) involves replacing the DNA of a donated egg with the DNA from a patient's cell and coaxing the egg to divide and produce embryonic stem cells. These are then manipulated and introduced back into the patient. Although a group of researchers in South Korea recently succeeded in using patient DNA in nuclear cloning to derive 11 new human embryonic stem cell lines (Hwang et al. Science. 2005;308:1777-1783), many efforts remain unsuccessful, and scientists are keen to find strategies for making nuclear cloning more efficient.The answer may lie in "genomic re-programming," said Rudolf Jaenisch, MD, of the Whitehead Institute for BiomedicalResearch, Cambridge, Mass. During the International Societyfor Stem Cell Research meeting held here in June, Jaenisch discussed his work to find the genes that are crucial to successful nuclear cloning.