Sperm-Producing Stem Cells Isolated, Grown

From Times Staff and Wire Reports

Working with mice, Pennsylvania researchers have isolated and grown stem cells that produce sperm, a feat that will allow them to produce massive numbers of sperm cells for research.

The feat, reported in the Proceedings of the National Academy of Sciences, is important because it will allow scientists to modify the sperm genetically, correcting genetic defects or introducing desirable traits.

The technique will initially be used for farm animals and endangered species, said Ralph Brinster of the University of Pennsylvania, but could ultimately be used on humans.