Molecular Analysis Of Circadian Clock Components In The Scorpion

The circadian clock which is present in nearly almost living organisms has a fundamental role in regulating biological temporal rhythms. It is tightly controlled by molecular components consisting of positive and negative regulatory elements that share a high degree of homology from one organism to the next. Circadian rhythms have been extensively studied at electrophysiological levels in scorpions, but not thoroughly at molecular levels. Here we try to reveal the possible core players that make circadian clock in the death stalker scorpion, Leiurus quinquestriatus. Scorpions were kept under light/dark cycle condition as of 12L/12D. At different time points, brains were dissected. Fixed brains were sectioned on slides to be ready for immunohistochemistry treatment. Positive signals were obtained with antibodies against TIMELESS, CLOCK, CYCLE, PDF (Pigment-dispersing factor) PERIOD1 and PERIOD2. PDF and CLOCK immunoreactivity was localized mainly in the supraosephageal ganglion (SOG) while signals for TIMLESS, PER1, CYCLE and PER2 were detected all over the brain. Our results suggest that scorpion clock components are much similar to those in insects than those of mammals.