Sperm Cells Created from Bone Marrow
Byline: By Alex Young
Immature sperm cells have been created from human bone marrow, it was revealed today.
The breakthrough raises the future possibility of manufacturing sperm that can be used in IVF treatment or to restore fertility to men made sterile by cancer therapy.
Such applications are still many years away. But scientists hope to grow fully formed sperm cells in as little as three years.
At the same time they fear that new legislation may bring the work to a halt.
The Government's recent fertility White Paper proposes a ban on using artificially created sperm or eggs in assisted reproduction.
The research, conducted in Germany, is published today in the journal Reproduction: Gamete Biology.
A team led by Prof Karim Nayernia, from the University of Gottingen, first took bone marrow from male volunteers. From the samples, they isolated mesenchymal stem cells, which have previously been shown to grow into body tissues such as muscle.
Stem cells are immature cells that can be made to follow different functional pathways.
Using a form of vitamin A, the scientists coaxed the mesenchymal cells to become primordial germ cells (PGCs) - the first stage in the genesis of sperm.
Specific genetic markers showed that some PGCs had further developed into more advanced spermatagonial stem cells.
Under normal circumstances, these cells eventually turn into mature, func-tional sperm that can fertilise an egg.
About three per cent of the original bone marrow stem cells were able to reach the point of being spermatagonial cells.
In earlier work Prof Nayernia derived sperm stem cells from mouse bone marrow and transplanted them into the animals' testes. …