Researchers from Kyoto University, Japan have turned mouse embryonic stem cells into sperm, effectively opening up a new avenue for infertility research and treatment, according to the article published in the journal Cell.

The scientists managed to coax the mouse embryonic stem cells into PGCs (primordial germ cells), i.e. sperm precursors. In science, a precursor is something that precedes – a substance from which another, usually more active or mature substance is formed. They demonstrated that the cells eventually form healthy sperm.

The authors wrote that:

“Such in vitro reconstitution of germ cell development represents one of the most fundamental challenges in biology.”

The stem cell derived PGCs were transplanted into mice that could not produce sperm normally. The PGCs produced what appeared to be normal-looking sperm; these then fertilized eggs successfully.

The fertilized eggs were then transplanted into female mice. These female mice produce healthy babies that eventually matured into fertile female and male adult mice.

The scientists say this procedure could be used with pluripotent stem cells that are derived from adult skin cells.

Pluripotent means the stem cell can develop into one of many different types of cells.

The authors wrote:

“Continued investigations aimed at in vitro reconstitution of germ cell development, including the induction of female PGCLCs and their descendants, will be crucial for a more comprehensive understanding of germ cell biology in general, as well as for the advancement of reproductive technology and medicine.”

Written by Christian Nordqvist