In as little as 5 years, scientists may be able to grow eggs and sperm from ordinary body cells, an international consortium of scientists and ethicists announced in a consensus statement yesterday. The technological advance could be a boon for infertile couples as well as for research on reproduction, providing policymakers don't ban the tools, the group says.
Last year scientists announced that they had learned to turn back the clock on body cells (ScienceNOW, 20 November 2007). By inserting a select group of genes, they were able to convert skin cells into pluripotent stem cells (PSC)--cells capable of developing into any type of body tissue. This capability has opened up a whole new world of research--and it's brought closer to reality the possibility of generating embryos from gametes (i.e., sperm and eggs) grown in the lab, bypassing the need to collect oocytes from women.
The consortium, known as the Hinxton Group, warns that "oversight structures" need to be in place before anyone attempts to deploy such gametes in human reproduction. Such a development raises a host of concerns that include safety issues and the specter of the "ultimate incest"--the same person supplying both egg and sperm. At the same time, the group urges policymakers to be "flexible" in regulating the new technologies, not only because of the insights they can offer into human development but also because they could present new options for infertile couples whose eggs or sperm is defective. In legislation currently being considered in the United Kingdom, it would be illegal to use gametes created in the lab to treat infertility.
Both supporters and critics of stem cell research are already talking about the possibility that gay and lesbian couples might be able to become biological parents with these techniques. The Hinxton Group, however, points out that at present scientists see no way to make eggs from male body cells or sperm from female body cells. The obstacles are particularly great in the latter case, because female cells carry no Y chromosome, which contains genes necessary for sperm production.
Even if the work is only confined to research, it will be hard to avoid controversy, says Ruth Faden, a bioethecist at the Johns Hopkins University Bloomberg School of Public Health in Baltimore, Maryland, and a member of the Hinxton Group. That's because researchers will need to create an embryo to test the viability of these laboratory-created gametes--a procedure bound to cause more than a bit of a stir.