Researchers from the Chinese Academy ofSciences have successfully created functional sperm cells from mousestem cells in the laboratory, then implanted those cells intorodents' egg cells to produce healthy, fertile offspring. While a lotmore work needs to be done before human trails could be considered,the breakthrough could be significant, with the potential to combatmale infertility.
Infertility is a common problem,affecting as many as 15 percent of couples. A major cause is afailure of precursor cells in the testes to go through a celldivision process called meiosis, which forms them into sperm cells.
While researchers have, in the past,successfully created precursor germ cells from stem cells in the lab,the new study is the first time that scientists have managed to coaxthose cells into turning into fully functional sperm cells.
The team began by exposing embryonicmouse stem cells to a mixture of chemicals that caused them to forminto precursor cells. Then, stepping beyond previous research, thecells were placed in an environment similar to that found in thetestes when meiosis occurs.
Mimicking the natural tissueenvironment, the precursor cells were exposed to testicularcells and relevant hormones, including testosterone. As hoped, thecells responded to their surroundings, undergoing complete meiosisand forming into sperm-like cells with the correct nuclear DNA andchromosomal content.
With that step complete, the team thenimplanted the lab-grown sperm into egg cells, and transferred theminto female mice. The embryos were found to develop normally, leadingto healthy and fertile offspring.
A lot more research needs to be donebefore human trials could even be considered, with the team planninga similar experiment using primates. At the very least, the work hasprovided a significant advance in our understanding of spermproduction and development.
"If proven to be safe and effectivein humans, our platform could potentially generate fully functionalsperm for artificial insemination or in vitro fertilizationtechniques," said senior study author Jiahao Sha. "Becausecurrently available treatments do not work for many couples, we hopethat our approach could substantially improve success rates for maleinfertility."
The findings of the research werepublished in the journal Cell Stem Cell.
Source: Chinese Academy of Sciences
