If men are having fertility issues, fixing the problem might be as easy as borrowing their own skin cells.
According to a news study reported by Fox News on Thursday, researchers first transformed men's skin cells into stem cells, then implanted the cells into the testes of mice where they formed sperm precursor cells.
Study researcher Renee Reijo Pera, who conducted the work while at Stanford University, says one issue is some of the stem cells formed tumors in the mice.
Pera and co-workers used skin samples from three infertile men, and two fertile men. They used the skin cells to produce induced pluripotent stem cells, which can become nearly any tissue in the body. These cells were then implanted into the testes of mice, where they turned into germ cells, which normally give rise to sperm in males.
However, in the study, the germ cells did not go on to form mature sperm in the mice, likely because of evolutionary differences between humans and mice that blocked the production of such mature cells, Pera said.
The stem cells from fertile men were much better at generating germ cells than those from infertile men. Still, the fact that the infertile men's stem cells produced germ cells at all was surprising.
The study shows infertile men have the potential to produce germ cells, but the cells are lost over time. Therefor, young boys with this mutation might be able to preserve their germ cells for the future by freezing samples.
The study helps researchers understand the earliest stages of sperm development.
Previously, the same group of researchers created germ cells from human embryonic stem cells. And last year, experiments in mice showed that skin cells of the animals can be turned into stem cells, which can then be turned into germ cells. When researchers implanted these germ cells in sterile mice, the mice became fertile.