The recent in vitro derivation of gamete‐like cells from mouse embryonic stem (mES) cells is a major breakthrough and lays down several challenges, both for the further scientific investigation and for the bioethical and biolegal discourse. We refer here to these cells as gamete‐like (sperm‐like or oocyte‐like, respectively), because at present there is still no evidence that these cells behave fully like bona fide sperm or oocytes, lacking the fundamental proof, i.e. combination with a normally derived gamete of the opposite (...) sex to yield a normal individual. However, the results published so far do show that these cells share some defining features of gametes. We discuss these results in the light of the bioethical and legal questions that are likely to arise would the same process become possible with human embryonic stem (hES) cells. (shrink)

The recent success in generating live offspring from embryonic stem cell –derived gametes in mice sparked visions of growing tailor-made sperm for men faced with infertility. However, although this development will almost certainly lead to new insights into the processes underlying spermatogenesis and thus in the possible causes of male infertility, it is less certain if deriving sperm from ES cells, which are in turn derived from a sterile man, can make someone a genetic parent. As the gap between newly (...) envisioned reproductive technologies and natural reproduction widens, the question thus needs to be asked if these possible therapies still lead to genetic parenthood. (shrink)

The compromise position that accepts the use and derivation of stem cells from spare in vitro fertilisation embryos but opposes the creation of embryos for these purposes is a very weak ethical position. This paper argues that whatever the basis is on which defenders of this viewpoint accord intrinsic value to the embryo, once they accept the creation and sacrifice of embryos to benefit infertile people with a child-wish, they do not have a sound moral argument to condemn the creation (...) and sacrifice of embryos to benefit ill and injured people. (shrink)

A number of recent papers have described the successful derivation of egg and sperm precursor cells from mouse embryonic stem cells—so-called “artificial” gametes. Although many scientific questions remain, this research suggests numerous new possibilities for stem cell research and assisted reproductive technology, if a similar breakthrough is achieved with human embryonic stem cells. The novel opportunities raised by artificial gametes also prompt new ethical questions, such as whether same-sex couples should be able to access this technology to have children who (...) are genetically related to them both.THE CREATION OF “ARTIFICIAL” GAMETESOver the past two years, a number of papers have been published detailing the first successful attempts at differentiating mouse embryonic stem cells into egg1 and sperm2 precursor cells. Previously, researchers had used embryonic stem cells to generate tissues such as brain, liver, and pancreatic cells, but not germ cells of any kind. Production of gamete precursor cells was achieved initially through allowing stem cell lines to differentiate more or less randomly, but recent research has focused on identifying the precise ways in which differentiation into gametes can be precipitated and controlled. These breakthroughs make it seem likely that ongoing research on human stem cells will yield similar possibilities,3 raising questions over the practicalities of what might be achieved with such “artificial” gametes. In turn, the novel opportunities presented by artificial gametes raise a number of ethical concerns.The initial breakthrough, namely the obtaining of egg cells from mouse stem cells, was achieved by means of relatively simple science. Rather than coaxing stem cells to develop into eggs using complicated cocktails of growth factors, researchers adopted standard cell culture conditions, but grew the cells at higher density than usual.3–6 Growing the cells in this way led to the formation of ovary-like cell aggregates, which (when separated and stimulated with …. (shrink)

The recent in vitro derivation of gamete‐like cells from mouse embryonic stem (mES) cells is a major breakthrough and lays down several challenges, both for the further scientific investigation and for the bioethical and biolegal discourse. We refer here to these cells as gamete‐like (sperm‐like or oocyte‐like, respectively), because at present there is still no evidence that these cells behave fully like bona fide sperm or oocytes, lacking the fundamental proof, i.e. combination with a normally derived gamete of the opposite (...) sex to yield a normal individual. However, the results published so far do show that these cells share some defining features of gametes. We discuss these results in the light of the bioethical and legal questions that are likely to arise would the same process become possible with human embryonic stem (hES) cells. (shrink)