Luciferase expression controlled by a viral gene promoter in a mammalian circadian pacemaker.
Retinal light exposure induces several immediate-early genes in the hypothalamic suprachiasmatic nucleus (SCN), which contains the major circadian pacemaker of mammals. Clock-controlled and light-induced genes expressed in the SCN such as c- and contain upstream regulatory elements similar to those of the major immediate-early gene (IE-1) of the human cytomegalovirus. IE-1 expression is critical for viral reactivation from latency and increases in response to agents acting through depolarization or the cAMP response element. To test whether IE-1 could be under circadian control, bioluminescence was imaged in individual SCN cells of brain slice cultures from transgenic mice containing the IE-1 enhancer/promoter upstream from the firefly luciferase gene. A small percentage of the cells in neonatal and adult cultures displayed circadian transgene expression, particularly ones near the dorsomedial edge of the SCN. Single-cell bioluminescence imaging revealed that the circadian pacemaker can regulate exogenous viral genes and could play a role in viral diseases.
Sigworth
L A
LA
Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403, USA.
Liao
L
L
Chandler
T R
TR
Geusz
M E
ME
D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D001517:Coleoptera / Q000235:genetics; D003587:Cytomegalovirus / Q000235:genetics*; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000502:physiology; D017781:Genes, Immediate-Early; D066298:In Vitro Techniques; D008156:Luciferases / Q000235:genetics*; D008163:Luminescent Measurements; D051379:Mice; D008815:Mice, Inbred Strains; D008822:Mice, Transgenic; D009474:Neurons / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000502:physiology*; D013493:Suprachiasmatic Nucleus / Q000502:physiology*
D008156:Luciferases