Spermatogonial stem cell (SSC) therapy could soon be the solution for treating male sterility (infertility) – a condition that affects one in every seven men of reproductive age worldwide. The treatment involves transferring sperm stem cells from the testis to a test tube, culturing them, and nudging them to become fully-fledged sperm. Essentially, it’s a jump-started for sperm production.
University of California San Diego School of Medicine researchers have developed a reliable method for doing this. While it’s too soon for the cells to be applicable in any clinical setting, their research is a big step in that direction – it’s the groundwork for game-changing developments for fertility medicine.
Miles Wilkinson, a professor of obstetrics, gynecology, and reproductive sciences at UC San Diego School of Medicine, said in a press release:
We think our approach — which is backed up by several techniques, including single-cell RNA-sequencing analysis — is a significant step toward bringing SSC therapy into the clinic.

The single-cell RNA sequencing technique is what made it possible to define the molecular characteristics specific to human SSCs and distinguish the SSCs from other cells in the testes. Then, using a method called germ-cell transplantation, they found that a key ingredient was an inhibitor of the AKT pathway – a cellular system that controls cell division and survival.
The AKT inhibition is what maintains human SSCs by halting the development of later-stage sperm precursors. The researchers used this to preserve the culture of human cells with the molecular characteristics of SSCs for two-to-four weeks.
Wilkinson said:
Next, our main goal is to learn how to maintain and expand human SSCs longer so they might be clinically useful.
SSCs are specialized cells that continually self-renew, making more SSCs – as many as 1,000 sperm every couple of seconds even — which go on to develop into sperm. They are how men can father children beyond the age of 65.
If the researchers can determine how to maintain the cells long enough to be useful, the breakthrough could open up brand-new parenting options for non-binary or transgender people, and help cisgender men who aren’t producing sperm.
