Sperm Cells from Mesenchyme: Can Women Produce Sperm?

Human germ cells have been created from bone marrow stem cells for the first time. The researchers used bone marrow from male volunteers in this case, but could female donor stem cells work as well? Here is what the researchers did:

The research published today (Friday, April 13 2007), in the academic journal Reproduction: Gamete Biology, was carried out in Germany* by a team of scientists led by Professor Karim Nayernia, formerly of the University of Göttingen but now of the North-east England Stem Cell Institute (NESCI), based at the Centre for Life in Newcastle upon Tyne.

For the experiment, Prof Nayernia and his team took bone marrow from male volunteers and isolated the mesenchymal stem cells. These cells have previously been found to grow into other body tissues such as muscle.

They cultured these cells in the laboratory and coaxed them into becoming male reproductive cells, which are scientifically known as ‘germ cells’. Genetic markers showed the presence of partly-developed sperm cells called spermatagonial stem cells, which are an early phase of the male germ cell development. In most men, spermatagonial cells eventually develop into mature, functional sperm but this progression was not achieved in this experiment.

Earlier research led by Prof Nayernia using mice, published in Laboratory Investigations, also created spermatagonial cells from mouse bone marrow. The cells were transplanted into mouse testes and were observed to undergo early meiosis - cell division - the next stage to them becoming mature sperm cells, although they did not develop further.

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Stem cell researchers are becoming very adept at leading various types of stem cells down differentiational paths. Notice that these stem cells were taken from adult human males. They did not differentiate into functioning sperm, perhaps because they were not implanted into living testicles. Soon, however, it should be possible to produce sperm from stem cells in vitro--without the need for testicles.

If stem cells from the bone marrow of human females could eventually be coaxed into becoming functioning sperm, the dreams of creating a sustinable all-woman society could at last be within reach.