A team in Germany has grown mouse embryonic stem cells (ESCs)-like cells from spermatagonial stem cells which normally turn into sperm. The cells can be grown into all tissues of the mouse body, suggesting that if the same could be done in men, it would provide patients with a source of tissue-matched cells for repairing any damaged organs or tissue.

So far, all colonies of human ESCs have been derived from surplus human embryos, leftover from infertility treatments.

The scientists first extracted spermatagonial stem cells from mouse testes, before growing them in the lab in a mixture of growth factors and nutrients which coaxed the cells into becoming ESC-like cells instead of sperm.

“We can turn these into all kinds of tissue, from beating cardiac and vascular cells to neurons, skin cells and liver cells,” says Gerd Hasenfuss of the Georg-August University of Göttingen. And the process worked in 27% of the mice they experimented on.

The team is already taking testicle-tissue samples under consent from patients undergoing operations for other conditions.

“The real news is the capacity to sustain these cells in culture and retain their ability to turn into all tissue,” says says Paul de Sousa at the University of Edinburgh. “But it may be a leap of faith to apply it in humans. I would be wary that things in humans would be as simple.”

Via New Scientist, Nature and BBC News.