Please use this identifier to cite or link to this item:
Title: Dissociation of Circadian and Circatidal Timekeeping in the Marine Crustacean Eurydice pulchra
Authors: Zhang, Lin
Hastings, Michael H.
Green, Edward W.
Tauber, Eran
Sladek, Martin
Webster, Simon G.
Kyriacou, Charalambos P.
Wilcockson, David C.
First Published: 26-Sep-2013
Publisher: Elsevier (Cell Press)
Citation: Current Biology, 2013, 23 (19), pp. 1863-1873
Abstract: Background: Tidal (12.4 hr) cycles of behavior and physiology adapt intertidal organisms to temporally complex coastal environments, yet their underlying mechanism is unknown. However, the very existence of an independent “circatidal” clock has been disputed, and it has been argued that tidal rhythms arise as a submultiple of a circadian clock, operating in dual oscillators whose outputs are held in antiphase i.e., ∼12.4 hr apart. Results: We demonstrate that the intertidal crustacean Eurydice pulchra (Leach) exhibits robust tidal cycles of swimming in parallel to circadian (24 hr) rhythms in behavioral, physiological and molecular phenotypes. Importantly, ∼12.4 hr cycles of swimming are sustained in constant conditions, they can be entrained by suitable stimuli, and they are temperature compensated, thereby meeting the three criteria that define a biological clock. Unexpectedly, tidal rhythms (like circadian rhythms) are sensitive to pharmacological inhibition of Casein kinase 1, suggesting the possibility of shared clock substrates. However, cloning the canonical circadian genes of E. pulchra to provide molecular markers of circadian timing and also reagents to disrupt it by RNAi revealed that environmental and molecular manipulations that confound circadian timing do not affect tidal timing. Thus, competent circadian timing is neither an inevitable nor necessary element of tidal timekeeping. Conclusions: We demonstrate that tidal rhythms are driven by a dedicated circatidal pacemaker that is distinct from the circadian system of E. pulchra, thereby resolving a long-standing debate regarding the nature of the circatidal mechanism.
DOI Link: 10.1016/j.cub.2013.08.038
ISSN: 0960-9822
eISSN: 1879-0445
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © 2013 The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Appears in Collections:Published Articles, Dept. of Genetics

Files in This Item:
File Description SizeFormat 
1-s2.0-S0960982213010440-main.pdfPublished (publisher PDF)1.32 MBAdobe PDFView/Open

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.