Artificial human sperm could come to the aid of infertile men, according to a team of scientists who have used lab-grown sperm to inseminate female mice.
Artificial sperm could also make males totally redundant, permitting women to give birth without a biological male mate.
Genetic scientists at the University of Goettingen in Germany have produced 65 mouse fetuses using sperm that was grown from embryonic stem cells.
Twelve baby mice have been born using this sperm, said Dr. Wolfgang Engel, director of Human Genetics at the university.
A sperm cell from an embryonic stem cell would still not give an infertile man a biological tie to his child, however. It would not be any different from using donor sperm.
Engel's team has turned to generating sperm from very early germ cells taken from the testicles.
Engel said if sperm could be grown in the lab, it would be possible to take early germ cells from one woman, turn them into sperm cells, and use those to fertilize the egg of another woman.