Milestone! Male mice produce functional eggs, and about 1% can produce offspring.
CTOnews.com, March 19, will men be able to have offspring one day? In a paper published in the journal Nature on the 16th, Lin Keyan's team at Kyushu University in Japan transformed stem cells from male mice into female cells and produced functional eggs. About 1% of these eggs can produce healthy offspring after fertilization. This is a landmark study that may promote future fertility research.
Sperm and eggs-that is, male and female gametes-are produced by a class of stem cells called primordial germ cells, which require sex chromosomes to function properly to differentiate into gametes. According to CTOnews.com, previous studies have explored the possibility of changing the sex of primordial germ cells, but found that only cells with low fertility can be produced. However, Lin Keyan's team at Kyushu University in Japan found that the use of pluripotent stem cells (including embryonic stem cells and induced pluripotent stem cells) is possible to produce more sound eggs.
The team used skin cells (carrying XY chromosomes) from the tails of mature male mice and transformed them into induced pluripotent stem cells. In the process of in vitro culture, some cells rarely lose the Y chromosome (about 6% of the cultured cells), or "XO" cells. These XO cells can continue to develop in the medium and induce X chromosome replication. The use of drug reversin that interferes with cell division can improve the replication efficiency of X chromosome. Finally, the obtained double X chromosome cells were induced to differentiate into primordial germ cell-like cells and then differentiated into egg cells. When these eggs are fertilized and implanted into the mouse uterus, they can produce viable offspring: about 1% of the transferred embryos can develop into cubs.
The researchers point out that there is a need for a more rigorous assessment of the effect of turning male cells into female cells on genome stability, which is important for future research and applications.
