A blind circadian clock in cavefish reveals that opsins mediate peripheral clock photoreception.

The circadian clock is synchronized with the day-night cycle primarily by light. Fish represent fascinating models for deciphering the light input pathway to the vertebrate clock since fish cell clocks are regulated by direct light exposure. Here we have performed a comparative, functional analysis...

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Bibliographic Details
Main Authors: Nicola Cavallari, Elena Frigato, Daniela Vallone, Nadine Fröhlich, Jose Fernando Lopez-Olmeda, Augusto Foà, Roberto Berti, Francisco Javier Sánchez-Vázquez, Cristiano Bertolucci, Nicholas S Foulkes
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2011-09-01
Series:PLoS Biology
Online Access:http://europepmc.org/articles/PMC3167789?pdf=render
Description
Summary:The circadian clock is synchronized with the day-night cycle primarily by light. Fish represent fascinating models for deciphering the light input pathway to the vertebrate clock since fish cell clocks are regulated by direct light exposure. Here we have performed a comparative, functional analysis of the circadian clock involving the zebrafish that is normally exposed to the day-night cycle and a cavefish species that has evolved in perpetual darkness. Our results reveal that the cavefish retains a food-entrainable clock that oscillates with an infradian period. Importantly, however, this clock is not regulated by light. This comparative study pinpoints the two extra-retinal photoreceptors Melanopsin (Opn4m2) and TMT-opsin as essential upstream elements of the peripheral clock light input pathway.
ISSN:1544-9173
1545-7885