A new breakthrough by scientists at Nanjing Medical University has led to the genetic engineering of functioning mice sperm cells from stem cells, which were then injected into egg cells that successfully produced fertile offspring, according to the International Business Times. The finding could help men that struggle to have children by producing sperm cells in vitro, but only if this same success can be replicated using human cells.
Creating sperm in the testes is one of the longest and most complex bodily processes, typically taking over a month to complete in most mammals, making the feat even more impressive, according to BBC News.
"I expect many think it is easy to make sperm, most men just sit there and make millions of the little blighters every hour," said Robin Lovell-Badge of the United Kingdom's Francis Crick Institute. "However, as this paper clearly shows, it is much more complex than this."
The team used the sperm cells of young mice between the ages of two and eight years old and extracted DNA from them. This extracted DNA this went through recombination in an attempt to make primordial germ cells derived from stem cells, which means they have the ability to become any kind of cell that they want despite their sex cell origins.
The results were promising; the team was able to used DNA recombination to push stem cells to redevelop as sperm cells again and retain the ability to conduct meiosis. These cells subsequently underwent in vitro fertilization that led to the creation of fertile mouse offspring.
"Reproducing germ cell development in vitro has remained a central goal in both reproductive biology and reproductive medicine," said Jiahao Sha, co-author of the study. "We established a robust, stepwise approach that recapitulates the formation of functional sperm-like cells in a dish. We think that it holds tremendous promise for treating male infertility."
Although the findings are a major breakthrough, much more research needs to be done in order to ensure the safety of the technique, Gizmodo reports. For example, the team does not know if the sperm had mutations lurking within them or if the offspring produced by the technique possessed genetic abnormalities that were not physically evident.
The findings were published in the Feb. 25 issue of Cell Press.
