Organisms With Clocks Outside of Circadian Rhythm
by Gretchen Vogel
Almost all organisms, from bacteria to mammals, have a circadian clock—a mechanism in their cells which keeps them in sync with Earth’s day-and-night cycle. But many organisms follow other rhythms as well: the tides, the months, or the seasons. Although researchers have documented these behaviors, no one has been sure whether these nondaily cycles use the same components as the circadian clock, or if they have their own clocks.
Two papers published today present the first evidence for clocks independent of the circadian one: a sea louse whose swimming patterns sync up with the tides, and a marine worm that matures and spawns in concert with the phases of the moon. The discoveries, by groups working independently, suggest that noncircadian clocks might be common and could explain a variety of biological rhythms…
(read more: Science News/AAAS)
photo: The marine worm Platynereis dumerilii, which matures and spawns in sync with the moon, by Zantke et al./Cell Reports