Medicine is now a step closer to curing male infertility in humans, after Chinese scientists created functioning mice sperm out of embryonic stem cells in a lab, which was then successfully injected into female mice, leading to a healthy offspring.
The scientific success in mice may make it possible one day, at least in theory, for doctors to turn human skin cells into sperm that could carry DNA to the offspring.
“If proven to be safe and effective in humans, our platform could potentially generate fully functional sperm for artificial insemination or in vitro fertilization techniques,” according to co-senior study author Jiahao Sha from Nanjing Medical University.
The discovery is creating a huge buzz in the medical community, as a lot of the current treatments are failing to help couples having problems conceiving.
“Because currently available treatments do not work for many couples, we hope that our approach could substantially improve success rates for male infertility,” Jiahao Sha said.
The study was published in the peer reviewed journal Cell Stem Cell by Qi Zhou and Xiao-Yang Zhao of the Institute of Zoology at the Chinese Academy of Sciences
To get a successful result, scientists mixed the embryonic stem cells of mice with a chemical mixture that caused the cells to turn into primordial germ cells. After that, the germ cells were exposed to testicular cells and testosterone hormones, among others. The final result was the transformation of the germ cells into “sperm-like cells with correct nuclear DNA and chromosomal content,” according to the published study.
The main reason this change was possible is connected to the fact that germ cells are able to take on the characteristics of other types of cells.
The next stage of the process was to inject the sperm-like cells into mouse egg cells, creating embryos that were later put into female mice.
One of the unique aspects of the study was that the resultant baby mice were not only healthy, but able to mate and successfully reproduce.
A total of 379 eggs were injected with this type of sperm, resulting in the creation of nine baby mice.
Some of the issues that the study notes include, “ethical concerns regarding the use of embryonic cells should be considered.”
The new technique is currently being tested in monkeys, Qi Zhou told AP.
Other researchers, however, warn that it will be a long process before the discovery could be applied to humans.
“This research is potentially interesting but requires independent verification,” Azim Surani, director of germline and epigenomics research at the University of Cambridge, said, as cited by AFP. “It also remains to be seen if this protocol could work with human stem cells because of the known differences between the mouse and human germline.”