Teleost multiple tissue (tmt) opsin: a candidate photopigment regulating the peripheral clocks of zebrafish?
Isolated organs and cell lines from zebrafish exhibit circadian oscillations in clock gene expression that can be entrained to a 24-h light/dark cycle. The mechanism underlying this cellular photosensitivity is unknown. We report the identification of a novel opsin family, tmt-opsin, that has a genomic structure characteristic of vertebrate photopigments, an amino acid identity equivalent to the known photopigment opsins, and the essential residues required for photopigment function. Significantly, tmt-opsin is expressed in a wide variety of neural and non-neural tissues, including a zebrafish embryonic cell line that exhibits a light entrainable clock. Collectively the data suggest that tmt-opsin is a strong candidate for the photic regulation of zebrafish peripheral clocks.
Moutsaki
Paraskevi
P
Department of Integrative and Molecular Neuroscience, Division of Neuroscience and Psychological Medicine, Imperial College Faculty of Medicine, Charing Cross Hospital, Fulham Palace Road, W6 8RF, London, UK.
Whitmore
David
D
Bellingham
James
J
Sakamoto
Katsuhiko
K
David-Gray
Zoë K
ZK
Foster
Russell G
RG
D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D001483:Base Sequence / Q000235:genetics; D001683:Biological Clocks / Q000502:physiology*; D001921:Brain / Q000378:metabolism; D002460:Cell Line / Q000166:cytology / Q000378:metabolism*; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D019143:Evolution, Molecular; D005786:Gene Expression Regulation / Q000235:genetics*; D015698:Genomic Library; D008969:Molecular Sequence Data; D017440:Photoperiod; D010802:Phylogeny; D017299:Rod Opsins / Q000235:genetics / Q000302:isolation & purification*; D017386:Sequence Homology, Amino Acid; D023741:Takifugu / Q000235:genetics / Q000378:metabolism*; D014781:Viscera / Q000378:metabolism; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism*
D018076:DNA, Complementary; D017299:Rod Opsins