Phase Shifts of the Circadian Locomotor Rhythm Induced by Pigment-Dispersing Factor in the Cricket Gryllus bimaculatus

• Published in: Zoological Science Vol. 20; no. 11; pp. 1347 - 1354
• Main Authors: Singaravel, Muniyandi, Fujisawa, Yuko, Hisada, Miki, Saifullah, A. S. M., Tomioka, Kenji
• Format: Journal Article
• Language: English; Japanese
• Published: Japan Zoological Society of Japan 01.11.2003; UniBio Press
• Subjects: Amino Acid Sequence; Animals; circadian rhythm; Circadian Rhythm - drug effects; Circadian Rhythm - physiology; crickets; Drosophila Proteins; Enzyme-Linked Immunosorbent Assay; Gryllidae; Gryllidae - genetics; Gryllidae - physiology; Gryllus bimaculatus; Molecular Sequence Data; Neuropeptides - genetics; Neuropeptides - pharmacology; Original s; phase response curve; phase shifts; pigment-dispersing factor; Pigment-dispersing factors; Sequence Analysis, DNA
• ISSN: 0289-0003
• DOI: 10.2108/zsj.20.1347

Pigment-dispersing factors (PDFs) are octadeca-peptides widely distributed in insect optic lobes and brain. In this study, we have purified PDF and determined its amino acid sequence in the cricket Gryllus bimaculatus. Its primary structure was NSEIINSLLGLPKVLNDA-NH2, homologous to other PDH family members so far reported. When injected into the optic lobe of experimentally blinded adult male crickets, Gryllus-PDF induced phase shifts in their activity rhythms in a phase dependent and dose dependent manner. The resulted phase response curve (PRC) showed delays during the late subjective night to early subjective day and advances during the mid subjective day to mid subjective night. The PRC was different in shape from those for light, serotonin and temperature. These results suggest that PDF plays a role in phase regulation of the circadian clock through a separate pathway from those of other known phase regulating agents.