Circadian regulation of iodopsin gene expression in embryonic photoreceptors in retinal cell culture.
A circadian clock regulates a number of diverse physiological functions in the vertebrate eye. In this study, we show that mRNA for the red-sensitive cone pigment, iodopsin, fluctuates with a circadian rhythm in chicken retina. Transcript levels increase in the late afternoon just prior to the time of cone disc shedding. Furthermore, iodopsin mRNA levels are regulated similarly by a circadian oscillator in primary cultures of dispersed embryonic chick retina. Nuclear run-on experiments show that the circadian regulation of iodopsin transcript abundance occurs at the level of gene transcription. Our results provide a demonstration of clock-regulated gene expression in a vertebrate preparation maintained in cell culture.
Pierce
M E
ME
NSF Center for Biological Timing, Northwestern University, Evanston, Illinois 60208.
Sheshberadaran
H
H
Zhang
Z
Z
Fox
L E
LE
Applebury
M L
ML
Takahashi
J S
JS
D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D002940:Circadian Rhythm; D015870:Gene Expression; D010786:Photoreceptor Cells / Q000196:embryology / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000196:embryology*; D012168:Retinal Pigments / Q000235:genetics*; D017299:Rod Opsins; D014158:Transcription, Genetic
D012333:RNA, Messenger; D012168:Retinal Pigments; D017299:Rod Opsins; C034941:iodopsin