Biological clock in total darkness: The Clock/MOP3 circadian system of the blind subterranean mole rat

Aaron Avivi, Urs Albrecht, Henrik Oster, Alma Joel, Avigdor Beiles, Eviatar Nevo

Research output: Contribution to journalArticlepeer-review


Blind subterranean mole rats retain a degenerated, subcutaneous, visually blind but functionally circadian eye involved in photoperiodic perception. Here we describe the cloning, sequence, and expression of the circadian Clock and MOP3 cDNAs of the Spalax ehrenbergi superspecies in Israel. Both genes are relatively conserved, although characterized by a significant number of amino acid substitutions. The glutamine-rich area of Clock, which is assumed to function in circadian rhythmicity, is expanded in Spalax compared with that of humans and mice, and is different in amino acid composition from that of rats. We also show that MOP3 is a bona fide partner of Spalax Clock and that the Spalax Clock/MOP3 dimer is less potent than its human counterpart in driving transcription. We suggest that this reduction in transcriptional activity may be attributed to the Spalax Clock glutamine-rich domain, which is unique in its amino acid composition compared with other studied mammalian species. Understanding Clock/MOP3 function could highlight circadian mechanisms in blind mammals and their unique pattern as a result of adapting to life underground.

Original languageEnglish
Pages (from-to)13751-13756
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number24
StatePublished - 20 Nov 2001

ASJC Scopus subject areas

  • General


Dive into the research topics of 'Biological clock in total darkness: The Clock/MOP3 circadian system of the blind subterranean mole rat'. Together they form a unique fingerprint.

Cite this