Disease relevance of Pdf

• PDF applied to the terminal abdominal ganglion triggers firing of action potentials in motoneurons with axons in the genital nerves of males and the 8th ventral nerve of females [1].

Psychiatry related information on Pdf

• The results clearly suggest that genetic ablation of LN(v)s and loss of function mutation of PDF abolish eclosion and locomotor activity rhythms, whereas the egg-laying rhythm continues unabated [2].

High impact information on Pdf

• A pdf neuropeptide gene mutation and ablation of PDF neurons each cause severe abnormalities of behavioral circadian rhythms in Drosophila [3].
• The SET motif, PDH fingers, zinc fingers and two other regions are most similar to domains of ALL-1 and TRX [4].
• So far, only the l-LN(v) and the PDF-positive s-LN(v) have been shown to project into the accessory medulla, a small neuropil that contains the circadian pacemaker center in several insects [5].
• We find that the large PDF-positive neurons are morphologically homogeneous and that their resting membrane potential is modulated both by the clock and by light inputs [6].
• Here we demonstrate that the putative targets of the Bolwig photoreceptors, the PDF-containing clock neurons (LNs), in the larval brain express functional ACh receptors (AChRs) [7].

Biological context of Pdf

• The PDF-encoding Drosophila gene (pdf) is intronless and present in a single copy per haploid genome [8].
• In Drosophila, PDF functions in some of the neurons expressing the clock genes period, timeless, Clock, and cycle, and those clock genes in turn regulate pdf gene expression [9].
• The model predicts that PDH affects the phosphorylation rate of clock genes and that in addition to PDH, another neuroactive substance is involved in the coupling pathway, via an all-advance type of interaction [10].
• 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) [11].

Anatomical context of Pdf

• When GFP-fused PDF precursor proteins were expressed in COS-7 cells, distinct translocation of the fusion protein into the nucleus was observed [9].
• In the wild-type and in all rhythmic mutants (small optic lobes, sine oculis, small optic lobes; sine oculis), eight cell bodies at the anterior base of the medulla (PDFMe neurons) exhibit intense PDH-like immunoreactivity [12].
• Because this action is blocked in calcium-free saline, it is likely that PDF acts via interneurons [1].
• Pigment-dispersing factor in the locust abdominal ganglia may have roles as circulating neurohormone and central neuromodulator [1].
• Since the flies studied here do not display hormonally controlled, fast pigment migrations, the PDH-like peptide may have a role as neurotransmitter or neuromodulator in the central nervous system, especially in the visual system, and a regulatory role in the stomatogastric system and the hind-gut [13].

Associations of Pdf with chemical compounds

• However, the role for LN(v)s in modulating cocaine responses is separable from their role as pacemaker neurons: ablation or functional silencing of the LN(v)s reduces cocaine sensitivity, while loss of the principal circadian neurotransmitter PDF has no effect [14].
• In the adult fly's brain, the PDF neurons have also been examined in double-labelled preparations made with a second antibody directed against the product of one of several clock genes: period (per), timeless (tim), or cryptochrome (cry) [15].
• Acetylcholine increases intracellular Ca2+ via nicotinic receptors in cultured PDF-containing clock neurons of Drosophila [7].
• The reducing agent dithiothreitol enhanced the genotoxic effects of PAP in the SMART; the reasons for this interaction remain to be elucidated [16].
• p-Aminophenol (PAP; as a component of, e.g., hair dyes, photographic developers, as adsorbent in gas filters, as a metabolite of various fungicides, pesticides and drugs) has been tested for genotoxicity in Drosophila by means of the sex-linked recessive lethal test (SLRLT) and the somatic mutation and recombination test (SMART) of the wing [16].

Other interactions of Pdf

• Expression of Lmo in the principal Drosophila circadian pacemaker cells, the PDF-expressing ventral lateral neurons (LN(v)s), is sufficient to confer normal cocaine sensitivity [14].

Analytical, diagnostic and therapeutic context of Pdf

• Among the strongly immunoreactive lamina PDF neurons, on electron microscopy we identified cells exhibiting distinct staining that is not only cytoplasmic but also nuclear [9].
• Extracts of heads from the blowfly Phormia terraenovae were assessed in a fiddler crab bioassay for PDH activity [13].
• Pigment-dispersing hormone-like peptide in the nervous system of the flies Phormia and Drosophila: immunocytochemistry and partial characterization [13].
• Immunocytochemistry, dose-response curves, gel filtration chromatography and reversed-phase HPLC, combined with bioassay and enzyme-linked immunosorbent assay (ELISA), indicate the presence of PDH-like peptide in the blowfly [13].
• PDH-like peptide is localized in the DCVs as shown by post-embedding immuno-electron microscopy [17].

References