Mice used in each experiment are being reared under controlled light-dark conditions. When the light-dark cycle is 12/12 hours, the starting time of the light period is “ZT0” and the starting time of the dark period is “ZT12”. “ZT” is the abbreviation for “Zeitgeber Time”. “Zeitgeber” in German is “Time giver” in English and refers to the “agent of entrainment”.
Light signal is an important cue for circadian rhythm entrainment. There are two types of light-sensing photoreceptor cells: rod cells that distinguish between light and dark and cone cells that distinguish between colors. Transducin (Gt), a trimer G protein expressed in photoreceptor cells, is necessary to transduce external light signals into intracellular signals. The α subunits of Gt are GNAT1 functioning in rod cells and GNAT2 functioning in cone cells.
Zebrafish are used in studies of light signal transduction and circadian rhythm, and staining with anti-GNAT2 antibody is useful for cone cells (Cones) detection.
This sample was kindly provided by Drs. Tomoya Shiraki, Ph.D., Daisuke Kojima, Ph.D., and Yoshitake Fukada, Ph.D.
(Department of Biophysical and Biochemistry, Graduate school of Science, The University of Tokyo.)