Television viewers may be tossing out their old rabbit ears in favor of sleeker digital receivers, but scientists are raising the microscopic equivalents of antennas to new prominence.
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Most cells in the body, from light-gathering eye cells to kidney cells to brain cells, sport a single, prominent hairlike structure sticking out like an index finger flashing the No. 1 sign. While cells can have other protrusions that serve as propellers or sweep away mucus and debris, the No. 1 “primary” cilia don’t whip or wiggle or brush anything along. For a long time, in fact, scientists have thought about primary cilia the way people think about their appendixes, as vestigial organs that may once have had a purpose but are largely useless today.