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Georg Mayer - One of the best experts on this subject based on the ideXlab platform.

  • analysis of Pigment Dispersing Factor neuropeptides and their receptor in a velvet worm
    Frontiers in Endocrinology, 2020
    Co-Authors: Christine Martin, Lars Hering, Monika Stengl, Niklas Metzendorf, Sarah Hormann, Sonja Kasten, Sonja Fuhrmann, Achim Werckenthin, Friedrich W Herberg, Georg Mayer
    Abstract:

    Pigment-Dispersing Factor neuropeptides (PDFs) occur in a wide range of protostomes including ecdysozoans (= molting animals) and lophotrochozoans (mollusks, annelids, flatworms, and allies). Studies in insects revealed that PDFs play a role as coupling Factors of circadian pacemaker cells, thereby controlling rest-activity rhythms. While the last common ancestor of protostomes most likely possessed only one pdf gene, two pdf homologs, pdf-I and pdf-II, might have been present in the last common ancestors of Ecdysozoa and Panarthropoda (Onychophora + Tardigrada + Arthropoda). One of these homologs, however, was subsequently lost in the tardigrade and arthropod lineages followed by independent duplications of pdf-I in tardigrades and decapod crustaceans. Due to the ancestral set of two pdf genes, the study of PDFs and their receptor (PDFR) in Onychophora might reveal the ancient organization and function of the PDF/PDFR system in panarthropods. Therefore, we deorphanized the PDF receptor and generated specific antibodies to localize the two PDF peptides and their receptor in the onychophoran Euperipatoides rowelli. We further conducted bioluminescence resonance energy transfer (BRET) experiments on cultured human cells (HEK293T) using an Epac-based sensor (Epac-L) to examine cAMP responses in transfected cells and to reveal potential differences in the interaction of PDF-I and PDF-II with PDFR from E. rowelli. These data show that PDF-II has a tenfold higher potency than PDF-I as an activating ligand. Double immunolabeling revealed that both peptides are co-expressed in E. rowelli but their respective levels of expression differ between specific cells: some neurons express the same amount of both peptides, while others exhibit higher levels of either PDF-I or PDF-II. The detection of the onychophoran PDF receptor in cells that additionally express the two PDF peptides suggests autoreception, whereas spatial separation of PDFR- and PDF-expressing cells supports hormonal release of PDF into the hemolymph. This suggests a dual role of PDF peptides-as hormones and as neurotransmitters/neuromodulators-in Onychophora.

  • evolution of Pigment Dispersing Factor neuropeptides in panarthropoda insights from onychophora velvet worms and tardigrada water bears
    The Journal of Comparative Neurology, 2015
    Co-Authors: Georg Mayer, Paul A. Stevenson, Lars Hering, Juliane M Stosch, Heinrich Dircksen
    Abstract:

    Pigment-Dispersing Factor (PDF) denotes a conserved family of homologous neuropeptides present in several invertebrate groups, including mollusks, nematodes, insects, and crustaceans (referred to here as Pigment-Dispersing hormone [PDH]). With regard to their encoding genes (pdf, pdh), insects possess only one, nematodes two, and decapod crustaceans up to three, but their phylogenetic relationship is unknown. To shed light on the origin and diversification of pdf/pdh homologs in Panarthropoda (Onychophora + Tardigrada + Arthropoda) and other molting animals (Ecdysozoa), we analyzed the transcriptomes of five distantly related onychophorans and a representative tardigrade and searched for putative pdf homologs in publically available genomes of other protostomes. This revealed only one pdf homolog in several mollusk and annelid species; two in Onychophora, Priapulida, and Nematoda; and three in Tardigrada. Phylogenetic analyses suggest that the last common ancestor of Panarthropoda possessed two pdf homologs, one of which was lost in the arthropod or arthropod/tardigrade lineage, followed by subsequent duplications of the remaining homolog in some taxa. Immunolocalization of PDF-like peptides in six onychophoran species, by using a broadly reactive antibody that recognizes PDF/PDH peptides in numerous species, revealed an elaborate system of neurons and fibers in their central and peripheral nervous systems. Large varicose projections in the heart suggest that the PDF neuropeptides functioned as both circulating hormones and locally released transmitters in the last common ancestor of Onychophora and Arthropoda. The lack of PDF-like-immunoreactive somata associated with the onychophoran optic ganglion conforms to the hypothesis that onychophoran eyes are homologous to the arthropod median ocelli. J. Comp. Neurol. 523:1865–1885, 2015 © 2015 Wiley Periodicals, Inc.

  • Evolution of Pigment‐Dispersing Factor neuropeptides in panarthropoda: Insights from onychophora (velvet worms) and tardigrada (water bears)
    The Journal of comparative neurology, 2015
    Co-Authors: Georg Mayer, Paul A. Stevenson, Lars Hering, Juliane M Stosch, Heinrich Dircksen
    Abstract:

    Pigment-Dispersing Factor (PDF) denotes a conserved family of homologous neuropeptides present in several invertebrate groups, including mollusks, nematodes, insects, and crustaceans (referred to here as Pigment-Dispersing hormone [PDH]). With regard to their encoding genes (pdf, pdh), insects possess only one, nematodes two, and decapod crustaceans up to three, but their phylogenetic relationship is unknown. To shed light on the origin and diversification of pdf/pdh homologs in Panarthropoda (Onychophora + Tardigrada + Arthropoda) and other molting animals (Ecdysozoa), we analyzed the transcriptomes of five distantly related onychophorans and a representative tardigrade and searched for putative pdf homologs in publically available genomes of other protostomes. This revealed only one pdf homolog in several mollusk and annelid species; two in Onychophora, Priapulida, and Nematoda; and three in Tardigrada. Phylogenetic analyses suggest that the last common ancestor of Panarthropoda possessed two pdf homologs, one of which was lost in the arthropod or arthropod/tardigrade lineage, followed by subsequent duplications of the remaining homolog in some taxa. Immunolocalization of PDF-like peptides in six onychophoran species, by using a broadly reactive antibody that recognizes PDF/PDH peptides in numerous species, revealed an elaborate system of neurons and fibers in their central and peripheral nervous systems. Large varicose projections in the heart suggest that the PDF neuropeptides functioned as both circulating hormones and locally released transmitters in the last common ancestor of Onychophora and Arthropoda. The lack of PDF-like-immunoreactive somata associated with the onychophoran optic ganglion conforms to the hypothesis that onychophoran eyes are homologous to the arthropod median ocelli. J. Comp. Neurol. 523:1865–1885, 2015 © 2015 Wiley Periodicals, Inc.

Sakiko Shiga - One of the best experts on this subject based on the ideXlab platform.

  • Neuroanatomy of pars intercerebralis neurons with special reference to their connections with neurons immunoreactive for Pigment-Dispersing Factor in the blow fly Protophormia terraenovae
    Cell and Tissue Research, 2015
    Co-Authors: Kouji Yasuyama, Hiroaki Hase, Sakiko Shiga
    Abstract:

    Input regions of pars intercerebralis (PI) neurons are examined by confocal and electron microscopies with special reference to their connections with neurons immunoreactive for Pigment-Dispersing Factor (PDF) in the blow fly, Protophormia terraenovae . PI neurons are a prerequisite for ovarian development under long-day conditions. Backfills from the cardiac recurrent nerve after severance of the posterior lateral tracts labeled thin fibers derived from the PI neurons in the superior medial protocerebrum. These PI fibers were mainly synapsin-negative and postsynaptic to unknown varicose profiles containing dense-core vesicles. Backfilled fibers in the periesophageal neuropils, derived from the PI neurons or neurons with somata in the subesophageal zone, were varicose and some were synapsin-positive. Electron microscopy revealed the presence of both presynaptic and postsynaptic sites in backfilled fibers in the periesophageal neuropils. Many PDF-immunoreactive varicosities were found in the superior medial and lateral protocerebrum and double-labeling showed that 60–88 % of PDF-immunoreactive varicosities were also synapsin-immunoreactive. Double-labeling with the backfills and PDF immunocytochemistry showed that the PI fibers and PDF-immunoreactive varicosities were located close to each other in the superior medial protocerebrum. Results of triple-labeling of PI neurons, PDF-immunoreactive neurons and synapsin-immunoreactive terminals demonstrated that the synapsin-positive PDF-immunoreactive varicosities contacted the PI fibers. These data suggest that PI neurons receive synaptic contacts from PDF-immunoreactive fibers, which are derived from circadian clock neurons, of small ventral lateral neurons (previously called OL2) or posterior dorsal (PD) neurons with somata in the pars lateralis.

  • involvement of the brain region containing Pigment Dispersing Factor immunoreactive neurons in the photoperiodic response of the bean bug riptortus pedestris
    The Journal of Experimental Biology, 2014
    Co-Authors: Tomoko Ikeno, Hideharu Numata, Shin G Goto, Sakiko Shiga
    Abstract:

    The concept of insect photoperiodism based on a circadian clock has been supported by many studies demonstrating that the behavioural circadian rhythm and the photoperiodic response are driven by the same circadian clock genes. However, the neuronal mechanism of the circadian clock underlying photoperiodism is poorly understood. To examine whether circadian rhythm and photoperiodism share a neuronal mechanism, we focused on the neurons that express neuropeptide Pigment-Dispersing Factor (PDF) in the bean bug, Riptortus pedestris. PDF has been identified as an important regulator of the insect circadian rhythm and is expressed in circadian clock neurons of various insect species. In R. pedestris, PDF immunoreactivity was detected in some clusters of cells and their fibres in the optic lobe and the protocerebrum. cDNA encoding a PDF precursor protein was highly conserved between R. pedestris and many other insects. Differences between day and night were not observed in the immunolabelling intensity in cell bodies of PDF-immunoreactive neurons and pdf mRNA expression levels in the head. Surgical removal of the region containing PDF-immunoreactive cell bodies at the medulla disrupted the photoperiodic regulation of diapause. However, gene suppression of pdf by RNA interference did not affect the photoperiodic response. These results suggest that the region containing PDF-immunoreactive somata is important for the photoperiodic response in R. pedestris, but pdf mRNA expression is probably not required for the response.

  • synaptic connections between eyelet photoreceptors and Pigment Dispersing Factor immunoreactive neurons of the blowfly protophormia terraenovae
    The Journal of Comparative Neurology, 2006
    Co-Authors: Kouji Yasuyama, Yoshinori Okada, Yoshitaka Hamanaka, Sakiko Shiga
    Abstract:

    Studies using various mutants of Drosophila melanogaster bearing defects in their visual system, including those of the retinal and extraretinal photoreceptor systems, have indicated that the extraretinal photoreceptor known as the Hofbauer-Buchner (H-B) eyelet plays an active, if subsidiary, role in the entrainment of circadian rhythms. In the present study, in the context of unraveling the function of extraretinal photoreception on circadian rhythms and photoperiodic responses, we searched for extraretinal photoreceptors in the blowfly, Protophormia terraenovae, and found that this fly has a homolog of the H-B eyelet. In addition, we show morphologically direct synaptic connections between the eyelet of P. terraenovae (called here Pt-eyelet, after the species' name) and Pigment-Dispersing Factor (PDF)-immunoreactive neurons, which are putative circadian pacemaker neurons, by immunogold electron microscopy combined with intracellular dye injection. The Pt-eyelet was found to reside in the middle of the posterior surface of the optic lobe between the retina and the lamina, as does the H-B eyelet. This extraretinal photoreceptor was composed of at least four photoreceptor cells equipped with well-organized microvillar rhabdomeres. Rhodopsin 6-like immunoreactivity and also the response to light stimuli clearly showed the Pt-eyelet to be functional. The Pt-eyelet terminals in the accessory medulla exhibited synaptic bouton-like appearances and formed divergent multiple-contact output synapses. Synaptic contacts from the Pt-eyelet terminal to the PDF-immunoreactive neurons were identified by the presence of presynaptic ribbons and accumulated synaptic vesicles. Their possible function is discussed in relation to previous studies on circadian rhythm and photoperiodic response of P. terraenovae. J. Comp. Neurol. 494:331–344, 2006. © 2005 Wiley-Liss, Inc.

  • Synaptic connections between Pigment-Dispersing Factor-immunoreactive neurons and neurons in the pars lateralis of the blow fly Protophormia terraenovae.
    The Journal of comparative neurology, 2005
    Co-Authors: Yoshitaka Hamanaka, Kouji Yasuyama, Hideharu Numata, Sakiko Shiga
    Abstract:

    In females of the blow fly Protophormia terraenovae, neurons with cell bodies in the pars lateralis (PL) projecting to the retrocerebral complex (designated as PL neurons) are necessary for the induction of reproductive diapause under short-day and low-temperature conditions. In the present study, neural connections between PL neurons and Pigment-Dispersing Factor (PDF)-immunoreactive neurons were examined via immunolight microscopy and immunoelectron microscopy combined with backfills through the cardiac-recurrent nerve. Immunolight microscopy showed that fibers of PL neurons overlapped with PDF-immunoreactive fibers in the dorsolateral region of the superior protocerebral neuropil. Immunoelectron microscopy showed that PDF-immunoreactive fibers formed output synapses with fibers of PL neurons and unlabeled neurons in a region dorsoanteriorly located with respect to the calyx of the mushroom body. The distribution of synaptic connections between PDF-immunoreactive fibers and the fibers of PL neurons was sparse. According to the projection patterns, PDF-immunoreactive fibers with synaptic connections with PL neurons appeared to originate from PDF-immunoreactive neurons with cell bodies at the base of the medulla of the optic lobe (medulla PDF neurons), which are putative circadian clock neurons in P. terraenovae. PDF immunoreactivity was restrictively detected in dense-core vesicles but not in clear synaptic vesicles. The present results suggest that medulla PDF neurons convey time or photoperiodic information to PL neurons for diapause induction through direct synaptic connections.

Heinrich Dircksen - One of the best experts on this subject based on the ideXlab platform.

  • evolution of Pigment Dispersing Factor neuropeptides in panarthropoda insights from onychophora velvet worms and tardigrada water bears
    The Journal of Comparative Neurology, 2015
    Co-Authors: Georg Mayer, Paul A. Stevenson, Lars Hering, Juliane M Stosch, Heinrich Dircksen
    Abstract:

    Pigment-Dispersing Factor (PDF) denotes a conserved family of homologous neuropeptides present in several invertebrate groups, including mollusks, nematodes, insects, and crustaceans (referred to here as Pigment-Dispersing hormone [PDH]). With regard to their encoding genes (pdf, pdh), insects possess only one, nematodes two, and decapod crustaceans up to three, but their phylogenetic relationship is unknown. To shed light on the origin and diversification of pdf/pdh homologs in Panarthropoda (Onychophora + Tardigrada + Arthropoda) and other molting animals (Ecdysozoa), we analyzed the transcriptomes of five distantly related onychophorans and a representative tardigrade and searched for putative pdf homologs in publically available genomes of other protostomes. This revealed only one pdf homolog in several mollusk and annelid species; two in Onychophora, Priapulida, and Nematoda; and three in Tardigrada. Phylogenetic analyses suggest that the last common ancestor of Panarthropoda possessed two pdf homologs, one of which was lost in the arthropod or arthropod/tardigrade lineage, followed by subsequent duplications of the remaining homolog in some taxa. Immunolocalization of PDF-like peptides in six onychophoran species, by using a broadly reactive antibody that recognizes PDF/PDH peptides in numerous species, revealed an elaborate system of neurons and fibers in their central and peripheral nervous systems. Large varicose projections in the heart suggest that the PDF neuropeptides functioned as both circulating hormones and locally released transmitters in the last common ancestor of Onychophora and Arthropoda. The lack of PDF-like-immunoreactive somata associated with the onychophoran optic ganglion conforms to the hypothesis that onychophoran eyes are homologous to the arthropod median ocelli. J. Comp. Neurol. 523:1865–1885, 2015 © 2015 Wiley Periodicals, Inc.

  • Evolution of Pigment‐Dispersing Factor neuropeptides in panarthropoda: Insights from onychophora (velvet worms) and tardigrada (water bears)
    The Journal of comparative neurology, 2015
    Co-Authors: Georg Mayer, Paul A. Stevenson, Lars Hering, Juliane M Stosch, Heinrich Dircksen
    Abstract:

    Pigment-Dispersing Factor (PDF) denotes a conserved family of homologous neuropeptides present in several invertebrate groups, including mollusks, nematodes, insects, and crustaceans (referred to here as Pigment-Dispersing hormone [PDH]). With regard to their encoding genes (pdf, pdh), insects possess only one, nematodes two, and decapod crustaceans up to three, but their phylogenetic relationship is unknown. To shed light on the origin and diversification of pdf/pdh homologs in Panarthropoda (Onychophora + Tardigrada + Arthropoda) and other molting animals (Ecdysozoa), we analyzed the transcriptomes of five distantly related onychophorans and a representative tardigrade and searched for putative pdf homologs in publically available genomes of other protostomes. This revealed only one pdf homolog in several mollusk and annelid species; two in Onychophora, Priapulida, and Nematoda; and three in Tardigrada. Phylogenetic analyses suggest that the last common ancestor of Panarthropoda possessed two pdf homologs, one of which was lost in the arthropod or arthropod/tardigrade lineage, followed by subsequent duplications of the remaining homolog in some taxa. Immunolocalization of PDF-like peptides in six onychophoran species, by using a broadly reactive antibody that recognizes PDF/PDH peptides in numerous species, revealed an elaborate system of neurons and fibers in their central and peripheral nervous systems. Large varicose projections in the heart suggest that the PDF neuropeptides functioned as both circulating hormones and locally released transmitters in the last common ancestor of Onychophora and Arthropoda. The lack of PDF-like-immunoreactive somata associated with the onychophoran optic ganglion conforms to the hypothesis that onychophoran eyes are homologous to the arthropod median ocelli. J. Comp. Neurol. 523:1865–1885, 2015 © 2015 Wiley Periodicals, Inc.

  • development of Pigment Dispersing hormone immunoreactive neurons in the american lobster homology to the insect circadian pacemaker system
    Cell and Tissue Research, 2009
    Co-Authors: Steffen Harzsch, Heinrich Dircksen, Barbara S Beltz
    Abstract:

    We have examined the development of Pigment-Dispersing hormone (PDH)-immunoreactive neurons in embryos of the American lobster Homarus americanus Milne Edwards, 1837 (Decapoda, Reptantia, Homarida) by using an antiserum against β-PDH. This peptide is detectable in the terminal medulla of the eyestalks and the protocerebrum where PDH immunoreactivity is present as early as 20% of embryonic development. During ontogenesis, an elaborate system of PDH-immunoreactive neurons and fibres develops in the eyestalks and the protocerebrum, whereas less labelling is present in the deuto- and tritocerebrum and the ventral nerve cord. The sinus gland is innervated by PDH neurites at hatching. This pattern of PDH immunoreactivity has been compared with that found in various insect species. Neurons immunoreactive to Pigment-Dispersing Factor in the medulla have been shown to be a central component of the system that generates the circadian rhythm in insects. Our results indicate that, in view of the position of the neuronal somata and projection patterns of their neurites, the immunolabelled medulla neurons in insects have homologous counterparts in the crustacean eyestalk. Since locomotory and other activities in crustaceans follow distinct circadian rhythms comparable with those observed in insects, we suggest that PDH-immunoreactive medulla neurons in crustaceans are involved in the generation of these rhythms.

  • Pigment-Dispersing Factor in the locust abdominal ganglia may have roles as circulating neurohormone and central neuromodulator.
    Journal of neurobiology, 2001
    Co-Authors: Magnus G.s. Persson, Heinrich Dircksen, Malin B. Eklund, J.eric Muren, Dick R Nassel
    Abstract:

    Pigment-Dispersing Factor (PDF) is a neuropeptide that has been indicated as a likely output signal from the circadian clock neurons in the brain of Drosophila. In addition to these brain neurons, there are PDF-immunoreactive (PDFI) neurons in the abdominal ganglia of Drosophila and other insects; the function of these neurons is not known. We have analyzed PDFI neurons in the abdominal ganglia of the locust Locusta migratoria. These PDFI neurons can first be detected at about 45% embryonic development and have an adult appearance at about 80%. In each of the abdominal ganglia (A3-A7) there is one pair of lateral PDFI neurons and in each of the A5-A7 ganglia there is additionally a pair of median neurons. The lateral neurons supply varicose branches to neurohemal areas of the lateral heart nerves and perisympathetic organs, whereas the median cells form processes in the terminal abdominal ganglion and supply terminals on the hindgut. Because PDF does not influence hindgut contractility, it is possible that also these median neurons release PDF into the circulation. Release from one or both the PDFI neuron types was confirmed by measurements of PDF-immunoreactivity in hemolymph by enzyme immunoassay. 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. Because this action is blocked in calcium-free saline, it is likely that PDF acts via interneurons. Thus, PDF seems to have a modulatory role in central neuronal circuits of the terminal abdominal ganglion that control muscles of genital organs.

Ayami Matsushima - One of the best experts on this subject based on the ideXlab platform.

  • Pigment-Dispersing Factor Affects Nocturnal Activity Rhythms, Photic Entrainment, and the Free-Running Period of the Circadian Clock in the Cricket Gryllus bimaculatus
    2016
    Co-Authors: Ayami Matsushima, Yasuyuki Shimohigashi, Kenji Tomioka
    Abstract:

    Circadian rhythms are about 24-h periodicities widely observed in a variety of insect behaviors, such as locomotion (Abe et al., 1997; Tomioka et al., 1997), hatching (Tomioka et al., 1991; Sauman et al., 1996; Sakamoto and Tomioka, 2007), and eclosion (Chang, 2006). The neural mechanism controlling the overt rhythms still largely remains to be elucidated. The Pigment-Dispersing Factor (PDF), an octadeca-neuropeptide, has been reported as a key circadian neuromodulator/neurotransmitter functioning in th

  • Pigment Dispersing Factor affects nocturnal activity rhythms photic entrainment and the free running period of the circadian clock in the cricket gryllus bimaculatus
    Journal of Biological Rhythms, 2011
    Co-Authors: Yoshiyuki Moriyama, Ehab Hassaneen, Alaa El-din Sallam, Ahmad Aboghalia, S G Karpova, Salah Abdelsalam, Ayami Matsushima
    Abstract:

    Pigment-Dispersing Factor (PDF) is a neuropeptide widely distributed in insect brains and plays important roles in the circadian system. In this study, we used RNA interference to study the role of...

  • Pigment Dispersing Factor affects nocturnal activity rhythms photic entrainment and the free running period of the circadian clock in the cricket gryllus bimaculatus
    Journal of Biological Rhythms, 2011
    Co-Authors: Yoshiyuki Moriyama, Ehab Hassaneen, Alaa El-din Sallam, Ahmad Aboghalia, S G Karpova, Salah Abdelsalam, Ayami Matsushima
    Abstract:

    Pigment-Dispersing Factor (PDF) is a neuropeptide widely distributed in insect brains and plays important roles in the circadian system. In this study, we used RNA interference to study the role of the Pigment-Dispersing Factor (pdf) gene in regulating circadian locomotor rhythms in the cricket, Gryllus bimaculatus. Injections of pdf double-stranded RNA (dspdf) effectively knocked down the pdf mRNA and PDF peptide levels. The treated crickets maintained the rhythm both under light-dark cycles (LD) and constant darkness (DD). However, they showed rhythms with reduced nocturnal activity with prominent peaks at lights-on and lights-off. Entrainability of dspdf-injected crickets was higher than control crickets as they required fewer cycles to resynchronize to the LD cycles shifted by 6 h. The free-running periods of the dspdf-injected crickets were shorter than those of control crickets in DD. These results suggest that PDF is not essential for the rhythm generation but involved in control of the nocturnality, photic entrainment, and fine tuning of the free-running period of the circadian clock.

  • cdna cloning of the housefly Pigment Dispersing Factor pdf precursor protein and its peptide comparison among the insect circadian neuropeptides
    Journal of Peptide Science, 2004
    Co-Authors: Ayami Matsushima, Miki Shimohigashi, Yoshiro Chuman, Seiji Sato, Yoshiya Tominaga, Yukimasa Takeda, Satoru Yokotani, Takeru Nose, Yasuyuki Shimohigashi
    Abstract:

    Pigment-Dispersing Factor (PDF), an 18-amino acid neuropeptide, is a principal circadian neurotransmitter for the circadian rhythms of the locomotor activity in flies. Recently, two completely different types of PDF precursor were clarified; that of the cricket Gryllus bimaculatus and that of the last-summer cicada Meimuna opalifera. The G. bimaculatus PDF precursor is extraordinarily short and comprises a nuclear localization signal (NLS), while the M. opalifera PDF precursor is of ordinary length, comparable to that seen for the precursors of crustacean β-PDH homologues. Although their PDF peptide regions were exactly the same, the regions containing a signal peptide combined with a PDF-associated peptide (PAP) were remarkably different from each other. Such a grouping suggested a fundamental role for the PAP peptide in the circadian clock, perhaps associated with PDF function. In the present study, the cDNA cloning of PDF from the adult brains of the housefly Musca domestica was carried out and it was found that an isolated clone (527 bp) encodes a PDF precursor protein of ordinary length. The PDF peptide shows a high sequence identity (78%–94%) and similarity (89%–100%) to insect PDFs and also to the crustacean β-PDH peptides. In particular, there is only a single amino acid difference between the PDFs of Musca and Drosophila; at position 14 Ser for Musca PDF and Asn for Drosophila PDF. A characteristic Ser10 in Drosophila was retained in Musca, indicating the presence of a structural profile unique to these PDFs. The results of sequence analyses suggest that Musca and Drosophila PDFs are to be considered members of a single group that has evolved structurally. When the primary structure of the PAP regions was compared, the Musca PDF precursor also belonged to the same group as that to which the Drosophila PDF precursor belongs. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.

  • a circadian neuropeptide Pigment Dispersing Factor pdf in the last summer cicada meimuna opalifera cdna cloning and immunocytochemistry
    Zoological Science, 2002
    Co-Authors: Seiji Sato, Yoshiro Chuman, Ayami Matsushima, Yasuyuki Shimohigashi, Yoshiya Tominaga, Miki Shimohigashi
    Abstract:

    Pigment-Dispersing Factor (PDF), an 18-amino acid neuropeptide, is a principal circadian neuromodulator functioning downstream of the insect brain's circadian clock, modulating daily rhythms of locomotor activity. Recently, we found that PDF precursors of the cricket Gryllus bimaculatus comprise a nuclear localization signal (NLS). Moreover, the nuclear localization of PDF immunoreactivity and the translocation of GFP-fused PDF precursor into the nucleus have both been demonstrated. These suggest a fundamental role for PDF peptide in the circadian clock system within the nucleus, in addition to its role in downstream neural events. In the present study, we carried out the cDNA cloning of PDF from adult brains of the last-summer cicada Meimuna opalifera, and found that an isolated clone (545 bp) encodes an ordinary PDF precursor protein. PDF peptide itself shows a high sequence identity (78-94%) and similarity (89-100%) to insect PDFs and also to the crustacean beta-PDH peptides. The computer-assisted sequence analysis of PDF precursor revealed a possible translocation into the nucleus, despite the lack of a definite NLS-like sequence. Using immunocytochemistry, the optic lobes of M. opalifera revealed PDF-immunoreactive neurons in both the medulla and lamina neuropiles. All these PDF cells exhibited prominent immunolabeling of both their perikarya and axons, but not their nuclei. Our results provide the first structural and immunocytochemical identification of PDF neurons in Hemiptera.

Ehab Hassaneen - One of the best experts on this subject based on the ideXlab platform.

  • circadian expression of period and the Pigment Dispersing Factor in the yellow white mutant drosophila melanogaster
    Egyptian Academic Journal of Biological Sciences, 2017
    Co-Authors: Ehab Hassaneen
    Abstract:

    Daily behavioral andphysiological rhythms in most animals are regulated by a circadian clock. Inthe fruit fly, Drosophila melanogaster, this clock consists of a networkof about 150 cerebral neurons. Different parameters of the fruit fly circadianlocomotion are attributed to specific neuronal subsets and the molecularrhythms of clock genes and proteins within them. To understand the clockmachinery, many clock mutant flies have been used. yellow white (y w) mutation in D. melanogaster cause impairedmelanisation, eye Pigmentation loss, and behavioral alterations includingchanges in circadian locomotion. This study investigates the possible molecularbackground for these circadian alterations. Results revealed that in the outputpathway of the clock, the Pigment-Dispersing Factor (PDF) expression wassuppressed in y w mutant fruit flies compared to Canton S (CS) wild-type in the PDF+ clock neurons. Onthe other hand, the degradation of the PERIOD (PER) protein was significantlydelayed in  yw mutants and their levels was higher, especially atthe transition from dark to light. The combined effect of elevated PER levelsand suppressed PDF signaling provides an explanation for the delayed morninglocomotor activity peak (M) and advanced evening peak (E) of y w fliescompared to CS.It could be concluded that mutations affecting eye Pigmentation like the y w mutationcould have profound effects on the circadian regulation of behavior and theirunderlying molecular oscillations in clock neurons. These effects reduce theplasticity and robustness of the circadian clock and expose the flies to higherlevels of the environmental risk of desiccation.

  • Pigment-Dispersing Factor affects circadian molecular oscillations in the cricket Gryllus bimaculatus
    Entomological Science, 2011
    Co-Authors: Ehab Hassaneen, Yoshiyuki Moriyama, Alaa El-din Sallam, Ahmad Abo-ghalia, Kenji Tomioka
    Abstract:

    Pigment-Dispersing Factor (PDF) is an important neurotransmitter in insect circadian systems. In the cricket Gryllus bimaculatus, it affects nocturnal activity, the free-running period and photic entrainment. In this study, to investigate whether these effects of PDF occur through a circadian molecular machinery, we measured mRNA levels of clock genes period (per) and timeless (tim) in crickets with pdf expression knocked-down by pdf RNAi. The pdf RNAi decreased per and tim mRNA levels during the night to reduce the amplitude of their oscillation. The phase of the rhythm advanced by about 4 h in terms of trough and/or peak phases. On the other hand, pdf mRNA levels were little affected by per and tim RNAi treatment. These results suggest that PDF affects the circadian rhythm at least in part through the circadian molecular oscillation while the circadian clock has little effect on the pdf expression.

  • Pigment Dispersing Factor affects nocturnal activity rhythms photic entrainment and the free running period of the circadian clock in the cricket gryllus bimaculatus
    Journal of Biological Rhythms, 2011
    Co-Authors: Yoshiyuki Moriyama, Ehab Hassaneen, Alaa El-din Sallam, Ahmad Aboghalia, S G Karpova, Salah Abdelsalam, Ayami Matsushima
    Abstract:

    Pigment-Dispersing Factor (PDF) is a neuropeptide widely distributed in insect brains and plays important roles in the circadian system. In this study, we used RNA interference to study the role of...

  • Pigment Dispersing Factor affects nocturnal activity rhythms photic entrainment and the free running period of the circadian clock in the cricket gryllus bimaculatus
    Journal of Biological Rhythms, 2011
    Co-Authors: Yoshiyuki Moriyama, Ehab Hassaneen, Alaa El-din Sallam, Ahmad Aboghalia, S G Karpova, Salah Abdelsalam, Ayami Matsushima
    Abstract:

    Pigment-Dispersing Factor (PDF) is a neuropeptide widely distributed in insect brains and plays important roles in the circadian system. In this study, we used RNA interference to study the role of the Pigment-Dispersing Factor (pdf) gene in regulating circadian locomotor rhythms in the cricket, Gryllus bimaculatus. Injections of pdf double-stranded RNA (dspdf) effectively knocked down the pdf mRNA and PDF peptide levels. The treated crickets maintained the rhythm both under light-dark cycles (LD) and constant darkness (DD). However, they showed rhythms with reduced nocturnal activity with prominent peaks at lights-on and lights-off. Entrainability of dspdf-injected crickets was higher than control crickets as they required fewer cycles to resynchronize to the LD cycles shifted by 6 h. The free-running periods of the dspdf-injected crickets were shorter than those of control crickets in DD. These results suggest that PDF is not essential for the rhythm generation but involved in control of the nocturnality, photic entrainment, and fine tuning of the free-running period of the circadian clock.