A team of research scientists at Stanford University was able to convert skin cells of infertile men into human sperm cells. They did this by taking the male skin cells and converting them into stem cells; the stem cells were then transplanted into mouse testicles, where they developed into human sperm cells. The resulting human sperm cells were “very immature,” however, indicating that a lot of research is still needed before the technique can be used to overcome certain kinds of male infertility.

Mice in laboratoryAs with so many scientific breakthroughs, one person’s provocative discovery is another person’s fear of abuse.

Renee Reijo Pera, now at Montana State University, devised the Stanford study when she was in California, often fielding the question from infertile people: can you help me? In their effort to help, Pera and her team of researchers developed the process she describes as “much easier than we expected.”

Pera’s research team started with skin cells donated by infertile men. The skin cells were converted in the laboratory into pluripotent stem cells. Pluripotent stem cells, derived from Latin words that mean several (pluri) and able (potens), are somewhat like a blank slate on a cellular level. Under the right circumstances, they can develop into cells specific to any organ or tissue in the body.

Pluripotent stem cells are similar to embryonic stem cells, which begin forming at conception, and develop into a baby during gestation. Stem cells produced after birth become the body’s repair system - replacing and replenishing dead or damaged cells everywhere in the body.

In Pera’s lab, these pluripotent human stem cells were inserted into the testes of mice. The activity of hormones, enzymes, gene expression, and other biological factors specific to male reproduction induced the stem cells to become sperm cells.

George Daley is a stem-cell research scientist at Harvard University. He hails the experiment as a “very provocative” step toward making sperm in laboratory settings.

Bioethicist Ronald Green isn’t so enthused, however. The Dartmouth professor fears the technique could be too easily misused. To illustrate his concerns, he turns to the famous actor George Clooney:

"So it is not impossible in the future that a movie star may find some of his hair follicles purloined and then on the market as donor sperm. You can imagine some clandestine sperm bank saying, 'We're selling George Clooney's sperm.'"


Green is also concerned tissue samples from people long dead could be used to bring them back to life. He feels this application could prove especially attractive to the children of a soldier killed in combat.

Green calls for crafting a new human right requiring “consent to being a parent” and rules that make misusing the technology a criminal offense.

Pera understands her study paves the way for misuse, as do so many scientific discoveries, but she remains optimistic that it won’t be. "Most people want to have their own child. It's not that they want to have somebody else's child — even George Clooney's child, in my estimation."

Source: Stein, Rob. “‘Provocative’ Research Turns Skin Cells Into Sperm.” NPR Shots. NPR. May 1, 2014. Web. May 10, 2014.