Sperm made in China | La Vanguardia
In a research study which could pave the way for treating male infertility and is yet another example of China's emergence as a major scientific power, Chinese biologists have managed to create lab-grown sperm cells for the first time.
Using mouse cells, researchers showed this in vitro-grown sperm to be functional. It was used to fertilise eggs, and implantation of the resulting embryos into female mice produced healthy and fertile offspring. "These findings give us a platform to investigate (...) in vitro human spermatogenesis”, concluded the authors of the paper whose results were published in Cell Stem Cell yesterday.
"This is a very important breakthrough, a genuine milestone", stresses Anna Veiga, Reproductive Biology specialist at the Barcelona Centre for Regenerative Medicine and Dexeus University Hospital. "This is a very complex process."
The biggest problem is that human sperms and eggs only have 23 chromosomes, while the cells from which they are obtained have 46. This means that when a sperm fuses with an egg, the cells of the embryo thus obtained once again have 46 chromosomes. In the case of the mice used to conduct the research, the process is the same, although their eggs and sperm cells have 20 chromosomes and the rest of the cells in their body have 40.
Both humans and mice halve the number of chromosomes in their gametes via a complex process known as meiosis. What the team led by Qi Zhou (Chinese Academy of Sciences in Beijing) and Jiahao Sha (Medical University of Nanking) has managed to achieve is to replicate all stages of meiosis in vitro.
In this case, experiments were performed using mouse embryonic stem cells. "If our platform proves to be safe and effective in humans, it could generate fully functional sperm cells for artificial insemination or in vitro fertilisation", said Jiahao Sha in a statement. "We hope that our strategy can improve the success rate of male infertility treatments".
A priori, this approach can also be used to create sperm cells from female cells, which could open the possibility for lesbian couples to have children genetically related to both partners.
However, “there is still a long way to go before this research can be applied to people", warns Anna Veiga. "For now, it has proven possible in mice, which is a success, but technical and ethical obstacles currently prevent it from being offered as a treatment for assisted reproduction".