Stem Cells Toward Sperm Cells And Back Again: Experiments Reverse Cells' Developmental Course

In experiments with fruit flies, Johns Hopkins scientists have restored the insect's sperm-making stem cells by triggering cells on the way to becoming sperm to reverse course. The unexpected findings are described in the May 13 issue of Science. Like all stem cells, the fruit fly's sperm-making stem cells can renew themselves or can develop into more specialized cells -- eventually sperm in this case. While a few types of fairly specialized cells can naturally revert to their stem cell origins at times -- think regrowth of salamanders' lost limbs -- the researchers' experiments document what is thought to be one the first clear examples of an artificially triggered reversal of cell fate in an adult creature.