munich

Now is not the right time to campaign for a relaxation of Germany's tight laws on human embryo research, as some scientists have demanded, according to a policy statement issued last week by the Deutsche Forschungsgemeinschaft (DFG), Germany's basic research funding agency.

Any attempt to reconsider the law could backfire, explains Rüdiger Wolfrum, vice-president of the DFG, because the public is not fully aware of the medical potential of human embryo research.

The DFG has assessed the existing laws to establish exactly how German researchers are placed to conduct research related to embryos. It finds that they are free to use one particular source of human embryonic stem cells — which are still capable of dividing and developing — for the many different lines of medical research which the DFG considers justified, including the development of cell transplantation therapies for incurable diseases such as Alzheimer's and Parkinson's.

The law does not allow researchers to use embryos developed from spare eggs collected during in vitro fertilization. The Embryo Protection Law confers a human egg with full human rights from the moment of fertilization. Attempts to bypass fertilization by transferring genetic material directly into an enucleated human egg — cloning — are also expressly forbidden.

But there is no legal impediment to scientists isolating primordial germ cells from aborted fetuses and culturing them under conditions that allow them to develop into pluripotent human stem cells, which are committed to developing into one particular sort of body tissue. Under normal conditions, a fertilized egg divides initially into totipotent cells, which have the potential to develop into any sort of tissue, and thus theoretically into a complete human, but they become pluripotent after a few cell divisions.

Scientists have already established that pluripotent stem cells may be generated from fetal material in mice. Studies in the United States indicate that this principle will also apply to human material (see Nature 397, 185; 1999), allowing researchers to bypass the need to handle legally protected totipotent cells. The DFG says it will support studies that further this area of research.

The DFG is aware of the ethical sensitivity of the issue. It calls for the establishment of a central committee to assess the ethical, legal and scientific implications of research proposals involving the use of human embryonic stem cells, and to monitor any projects undertaken. It also calls for a full and open discussion of all these issues at European level.