At the University of Yokohama (Japan), they managed to grow viable sperm in vitro. "Products" are capable of fertilizing an egg and producing normal offspring
Researchers took sperm progenitor cells from the testes of newborn mice and placed them on an agarose gel saturated with nutrients and hormones, including testosterone. As they matured, the sperm began to glow green, as the mice were inserted the gene for a green fluorescent protein, which was turned on only in full-fledged mature germ cells.
About one month after sperm plating in agarose gel, fluorescent greens were seen in about half of the experimental samples.
When tested for "capacity", these spermatozoa turned out to be quite functional: if they were given a date with an egg and then implanted it in a female mouse, the result was normal, healthy offspring. No reproductive disturbances were observed in mice - neither in females nor in males.
World science has been striving for such a result for many years, but until now the history of "artificial sperm" has been a series of mistakes and failures. The most successful predecessors of the Japanese, researchers from the University of Newcastle (UK), were able to convert stem cells of mouse embryos into sperm, but the offspring resulting from the fusion of such sperm with an egg died prematurely. For the first time, a group from Yokohama University managed to find a recipe for a nutritional formula that can “feed” male reproductive cells at all stages of maturation.
A report on this study was published in the journal Nature.
The discovery can serve to overcome the problems of male infertility. If spermatozoa for some reason cannot mature correctly by themselves, they can be entrusted to the care of specialists who will make them "real men" - normal functional germ cells.