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.
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.