According to a recent article (see HERE), a team of researchers has managed to produce human functional spermatids (as sperm precursor cells are known) from human spermatogonial stem cells (SSC), testicular sperm cell precursors. The SSCs were isolated and identified phenotypically to ensure their cellular specificity.
The sperm cells generated from the human SSCs were able to fertilize mouse oocytes, subsequently enabling the development of hybrid embryos.
The creation of viable human-mouse hybrids is an ethically questionable practice
From a bioethical point of view, the first difficulty identified is the creation of viable human-mouse hybrids, which is ethically very questionable, although these types of hybridizations are common in scientific experiments similar to that discussed in this article; nevertheless, this does not justify them ethically (see our special report on f the biological status of the embryo).
See our special report Human-sheep hybrids created for the first time
Bioethical assessment of possible applications of this practice in clinical trials
The following bioethical comments can be noted:
- The sperm cells were generated from human SSCs. This, in principle, presents no bioethical difficulty, because SSCs are adult cells that can be obtained by testicular aspiration.
- In the paper, the authors confirm that the sperm cells generated were capable of fertilizing mouse oocytes and that hybrid mouse embryos were born from these. This confirms the functional capacity of the cells produced.
- As the study authors say, it provides valuable data for possible use of this technique in humans and, consequently, for preventing any type of male infertility.
- In any case, the cells from which the sperm cells were created are, in principle, normal cells, as they were extracted from the testicles of men with obstructive azoospermia, i.e. infertility would not be linked to a malfunction of the patient’s sperm cells, but to an obstruction subsequent to their genesis.
- It is, therefore, our opinion that this technique would be useful for this type of male infertility, “obstructive azoospermia”, only.
- In any case, from a bioethical point of view, it should be taken into account that, although in our opinion obtaining sperm cells from testicular SSCs offers no objective bioethical difficulty, as we have said, we do believe that using the cells produced in order to achieve a pregnancy would have to be done through assisted reproduction, with the bioethical difficulties that this presents.