美国科学60秒 SSS 2013-02-12（在线收听）

 　　Taste may be the least understood of our five senses, even basic questions like where the taste bugs come from remain mysterious until now. In the study published in the journal Stem Cell, scientists identified the lose of parental cell that gives rise to the daughter cell responsible for taste. Taste bugs are made of lusters of taste cells, which contain the receptors for sweet, salty, sour, bitter, and umami. The are concentrated in the bumpy papillae that covered the tongue surface. But taste bugs are not static *. The resident taste cells live only about too weeks before being replaced by new born baby taste cells. After all the bits * now permanent. But no one knew the address of taste cell nursery. To track it down, scientists scanned the tongue for cell that produced the same marker protein as the body's other stem cells, which give rise to our other specialized cells. The researchers discovered the reservoir of stem cells that lie in the trenches around the papillae at the back of the tongue. This stem cells can produce all of the different taste cell types and so allow us to savor all of life's flavors.