Intimations of Immortality: Advances in Assisted Reproductive Technology Promise New Choices - and Tricky Ethical Dilemmas

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Advances in assisted reproductive technology promise new choices -- and tricky ethical dilemmas.

Recent accomplishments by veterinary researchers may have far-reaching implications for human genetics, a field already rife with questions that do not fit easily into the existing body of public laws and policies.

Researchers from the University of Pennsylvania's School of Veterinary Medicine have frozen the spermatogonial stem cells of mice -- the cells from which male animals, including humans, produce sperm. They then thawed the cells and successfully implanted them in the testes of different mice. The researchers also demonstrated that the stem cells could be implanted in different species, such as rats, which could act as host carriers for the sperm of endangered animals.

While freezing sperm cells is nothing new, freezing stem cells has some dramatic implications. If the new technique were used on humans, for example, stem cells from a man undergoing chemotherapy treatments -- which can destroy such cells -- could be stored for later regeneration. Stem cells also could be extracted from a boy who is not yet producing sperm for later reimplantation when chemotherapy no longer is a danger to his reproductive abilities.

Stem cells regenerate themselves -- they reproduce indefinitely -- and thus they provide a virtually unlimited supply of sperm from a single donor. In the animal world, such a capability could enhance efforts to save endangered species. Not only can the reproductive cells be preserved, but sperm from previous generations can be introduced periodically to improve the diversity of a species.

The troublesome aspect, as some bioethicists see it, is that the same thing might be done with humans. One man could father children long after his death -- theoretically as long as the human race survived.

According to Glenn McGee, professor of bioethics at the University of Pennsylvania and a close observer of the research, stem-cell storage and regeneration represents another piece in a puzzle that technology is rapidly solving. "One day," he tells Insight, "we'll be able to make copies of people. The question is, should we?"

The difficulty, as McGee sees it, is the lag in public policy in addressing such issues. While professional ethics committees routinely observe and oversee human studies, no comparable bodies oversee veterinary activities, even though such research frequently yields discoveries -- like sperm stem-cell regeneration -- with profound human implications. At present, those discoveries can move unrestricted from veterinary research into commercial applications.

In a worst-case scenario, McGee says, the current situation "makes possible a consumer market for genetic material." In fact, such a case is nearly a reality in the field of in vitro fertilization, which McGee says is virtually unregulated. …