Narrator: This is Science Today. Cilia are microscopic, hairlike projections on the surface of cells that perform a variety of tasks. They do everything from getting the mucus out of your airway to giving you a sense of smell. Recently, scientists at the University of California, San Francisco, have discovered that defects in cilia function may in fact be responsible for a number of genetic disorders.
Marshall: There's a lot of human patients who are dying because their cilia are not moving properly. So it's a huge issue.
Narrator: Biochemist Wallace Marshall has been studying how cilia direct movement to help explain what goes wrong in these genetic disorders. To help unravel this mystery of human disease, he has turned to an unexpected organism: a tiny brown flatworm.
Marshall: So, what we came up with was the planarian flat worm, which the reason we care about them is because they crawl using an array of cilia that looks just like the array of cilia in the airway of your trachea and actually they even secrete mucus so it's just like a piece of your airway that crawled out on its own and is crawling around on the ground.
Narrator: For Science Today, I'm Larissa Branin.