title: Chronobiological analysis and mass spectrometric characterization of pigment-dispersing factor in the cockroach Leucophaea maderae.
abstract: Pigment-dispersing factor (PDF) is a neuropeptide that plays a prominent role in the circadian clock of several insects. The cockroach Leucophaea maderae was the first animal where the site of a biological clock could be located, and still is a focal point of circadian research. Although detailed studies on the action of pigment-dispersing factor and the distribution of PDF-like immunoreactivity in the L. maderae brain exist, a native pigment-dispersing factor of this species has not been characterized so far. The authentic Lem-PDF was isolated from L. maderae by a combination of high performance liquid chromatography, crab pigment-dispersion bioassay and an immunosorbent assay. Mass spectrometric characterization and the conserved sequence of pigment-dispersing factor in orthopteromorphan insects suggest that Lem-PDF has the sequence NSEXINSLLGLPKVLNDAa (where X= I or L). Lem-PDF is thus identical to either Periplaneta americana PDF or Acheta domesticus PDF. Detailed analysis of PDF-like immunofluorescence in different regions of the brain suggests that there are no drastic daily changes in the amount of pigment-dispersing factor as occur in Drosophila melanogaster, which might be explained by a lack of circadian pigment-dispersing factor release and production, or by phase differences between the pigment-dispersing factor neurons.
authors.affiliation: Department of Zoology, Stockholm University, Stockholm, Sweden.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Hamasaka
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Mohrherr
authors.forename: Reinhard
authors.initials: R
authors.lastname: Predel
authors.forename: Christian
authors.initials: C
authors.lastname: Wegener
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002940:Circadian Rhythm; D003058:Cockroaches / Q000502:physiology*; D013058:Mass Spectrometry; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D010455:Peptides; C027714:melanophore-dispersing hormone