Other uses for laboratory-produced sperm?
Last week, scientists in the United Kingdom announced the derivation of primitive human sperm cells from embryonic stem cells. The researchers say they hope to use the technique to study sperm development, and perhaps eventually to treat male infertility. But since pluripotent stem cells can also be developed from normal skin cells, such a technique--if perfected--could also be used for other purposes, including troubling ones.
Media commentary on the lab-produced sperm focused on the prospect of creating sperm from women, leading to speculation about two women producing a child genetically related to both of them, and about a neo-Amazonian world without men. Another scenario is based on the realization that with this technique, sperm could be obtained from any human, with or without consent, and used by a fan or stalker to become pregnant with the genetic child of her obsession.
These futures aren’t possible just yet. This experiment used pluripotent stem cells derived from embryos, not living humans. Several experts are skeptical of the quality of sperm produced in these attempts. And the researchers made much less progress producing precursor sperm using stem cells lines derived from XX (female) embryos.
My colleague Marcy Darnovsky has written about previous advocacy for developing female sperm and male eggs (1, 2, 3 [PDF]). She argues that bringing babies to term from lab-produced gametes would be inherently unsafe, in a manner akin to reproductive cloning, and that same-sex couples should not be targeted for experimental techniques that are too unsafe for straight couples.
But what about the more technically feasible case of stem cell sperm from men? A week before the release of the scientific paper, a group of libertarian bioethicists and stem cell researchers placed a stake in the ground. In a paper in Cell: Stem Cell, the six authors, which include two extremely libertarian bioethicists (1, 2), elaborate on a year-old consensus statement developed by "more than 40 scientists, ethicists, journal editors, and lawyers" under the umbrella of the Hinxton Group.
The bioethicists authors of the bioethics article dismiss, even in the long term, the potential of male eggs and female sperm. Instead, they cite three key uses of pluripotent stem cell derived gametes. First, they could greatly increase they supply of human eggs available for research, such as for cloning. However, it is unclear to me how laboratory-produced eggs would be able to properly mature. Second, these eggs could also mean production of greater numbers of embryos during in vitro fertilization and thus more options with preimplantation genetic diagnosis:
This technology may also facilitate the production of significantly larger quantities of eggs and, subsequently, embryos than current assisted reproductive technologies, vastly increasing the possibilities for embryo selection based on genetic profile. For example, if a couple is interested in selecting embryos for implantation based on multiple alleles, whether related to disease risk or phenotypic traits such as eye color, the potential mother’s PSC [pluripotent stem cell]-derived eggs could be used to create hundreds of embryos, ensuring that all of the desired alleles are present together in at least one embryo. This approach will not only raise concerns about the creation of huge numbers of embryos in excess of clinical need, but will also fuel debates about designer babies and which traits, if any, are legitimate targets of selection.
Third, the original stem cells could easily be genetically modified, yielding modified gametes, embryos, and humans:
Germline genetic modification of humans, be it for the correction of disease mutations or genetic enhancement (for example, to confer disease resistance or increase height), will raise serious moral concerns for some.
How should policymakers respond? The authors’ first recommendation is to err on the side of permissiveness:
Though social values should be part of any policy discussion that takes place, policymakers should not attempt to restrict scientific inquiry solely because there are divergent moral views among interested parties. That is, the mere presence of moral disagreement does not justify the regulation of the science; as science progresses, moral disagreement is inevitable. Moral disagreement does, however, signal the need for public discussion and debate and the engagement of scientists with the public and policymakers. Some disagreements about the methods or consequences of science reflect deep-seated differences in moral standpoints that are not easily reconcilable and that will require policymakers to take substantive positions that will remain unacceptable to some. Insofar as the result of such a process is the development of a restrictive policy, it is important to target it specifically to those dimensions of the research or its applications that have been determined to be unacceptable. It is also important that these policies be proportionate to the magnitude of what is morally at stake.
On of the authors and group members, John Harris of the University of Manchester and editor-in-chief of the Journal of Medical Ethics, took these arguments a step further in an op-ed in The Independent. There, he equates the choice of our partners with genetic modification:
Might we see the George Clooney stem cell line (assuming he were to consent to it)? I can see no objection. It is no more wrong to choose the genes of your child than your reproductive partner. Indeed, we have always sought to do both, choosing our partners on the basis of our – sometimes erroneous – belief about the sort of children likely to result. I see nothing wrong with people exercising that choice using the technology as it becomes available.
If it is not wrong to wish for a bouncing brown-eyed baby girl, why would it become wrong once we had the technology to play Fairy Godmother to ourselves and grant our own wish?
In the past, Harris has argued for compulsory inclusion in medical experiments (including of children), eugenics, bringing human-animal hybrids to term, and the dismissal of human rights as we know them. Given his past advocacy, Harris’s his current faux-naif wish list should be no surprise.
Previously on Biopolitical Times: