All-Female Conception: Women May Be Able to Produce Sperm

Professor Karim Nayernia of the University of Newcastle upon Tyne has been working for years on ways to produce artificial sperm. Last year he led a group of German scientists at the University of Gottingen in using embryonic mouse cells to create viable artificial sperm that were then used to produce seven live baby mice.

Nayernia’s latest research project focuses on using stem cells derived from human bone marrow to develop synthetic sperm cells. Findings from his most recent research were published this week in the journal Reproduction: Gamete Biology. The study showed that male bone marrow can be used to create the first stage of "spermatogonial" stem cells that will mature into full developed sperm cells capable of conception.

The researchers say that they have already created spermatogonial cells from bone marrow tissue taken from men, which may make it possible for scientists one day soon to restore fertility for men who are unable to produce sperm naturally. Having succeeded in the procedure using male bone marrow, the researchers are seeking ethical permission to attempt to create synthetic sperm cells from a woman’s bone marrow tissue.

"Theoretically it is possible," said Nayernia. "The problem is whether the sperm cells are functional or not. I don't think there is an ethical barrier, so long as it's safe. We are in the process of applying for ethical approval. We are preparing now to apply to use the existing bone marrow stem cell bank here in Newcastle. We need permission from the patient who supplied the bone marrow, the ethics committee and the hospital itself."

If bone marrow tissue from women can be used to create synthetic sperm cells, the possibility of all-female conception would be closer than ever before. But sperm created from women would be able to produce only daughters, because the Y chromosome found in male sperm is needed to create male fetuses.

Nayernia said that if scientists are able to develop sperm cells from female bone marrow tissue, the cells will be matured in a laboratory and tested using a standard fertility test for sperm—whether or not the cells are able to penetrate a hamster’s egg. Nayernia said that the researchers will test the functionality of any male and female sperm that is made synthetically. But he denied that scientists have any plans to produce female sperm and use it to fertilize a human egg. To do so would require the approval of Britain’s Human Fertilisation and Embryology Authority.

"Our next goal is to see if we can get the spermatagonial stem cells to progress to mature sperm in the laboratory and this should take around three to five years of experiments," Professor Nayernia said. The immediate goal for researchers is to determine whether or not female bone marrow can be used to make sperm cells. But the ultimate goal is to determine whether such secondary stem cells can be used to make other useful tissues of the human body.

The lengths to which Nayernia’s research can proceed will depend upon legislation being prepared by the British government to replace the existing Human Fertilisation and Embryology Act.