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Szyszka P, Galizia CG. The Role of the Sucrose-Responsive IR60b Neuron for Drosophila melanogaster: A Hypothesis. Chem Senses 2019; 43:311-312. [PMID: 29546407 PMCID: PMC5967455 DOI: 10.1093/chemse/bjy020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In a recent paper, Joseph and colleagues (Joseph et al. 2017) have characterized an IR60b receptor-expressing neuron in Drosophila. They showed that it responds to sucrose and serves to limit sucrose consumption, and proposed that it may thereby act to prevent overfeeding. Here, we propose an alternative hypothesis for the functional role of sucrose feeding control, and for how this limitation of sucrose uptake is accomplished. Adult fruit flies feed by excreting saliva onto the food, and imbibing the predigested liquefied food, or by filling the crop, where the food is predigested. Enzymes in the saliva hydrolyze starch and disaccharides into absorbable monosaccharides. Premature ingestion into the midgut would not give the enzymes in the saliva enough time to predigest the food. Thus, IR60b neurons might serve as a sensor to monitor the digestive state of external food or crop content: when disaccharides (sucrose) concentration is high, ingestion to the gut is inhibited, keeping a low concentration of starch and disaccharides in the midgut.
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Affiliation(s)
- Paul Szyszka
- Department of Biology, University of Konstanz, Universitätsstr., Konstanz, Germany
| | - C Giovanni Galizia
- Department of Biology, University of Konstanz, Universitätsstr., Konstanz, Germany
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Maeda H, Hatta T, Alim MA, Tsubokawa D, Mikami F, Kusakisako K, Matsubayashi M, Umemiya-Shirafuji R, Tsuji N, Tanaka T. Initial development of Babesia ovata in the tick midgut. Vet Parasitol 2016; 233:39-42. [PMID: 28043386 DOI: 10.1016/j.vetpar.2016.11.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 11/23/2016] [Accepted: 11/26/2016] [Indexed: 01/13/2023]
Abstract
The initial development of Babesia ovata in the midgut of the vector tick Haemaphysalis longicornis has been demonstrated through in vitro and in vivo studies. Although the research on the partial developmental cycles of B. ovata in the tick midgut was performed in our previous study by using ticks fed on experimentally B. ovata-infected cattle, detailed information on the developmental stages of B. ovata in H. longicornis was limited. This report describes the sequential development of stages of B. ovata in an in vitro study using B. ovata-infected erythrocytes and tick midgut contents. The in vivo study also confirmed the developmental stages in the midgut contents of artificially B. ovata-infected ticks. In this observation, we have recognized the distinct forms of B. ovata developmental stages in the tick midgut; the aggregation forms and ray bodies with shorter spikes and light-stained cytoplasm were shown by Giemsa staining. The similarities and differences of the stages as compared to previous reports have been discussed.
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Affiliation(s)
- Hiroki Maeda
- Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, Korimoto, 1-21-24 Korimoto, Kagoshima 890-0065, Japan; Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan
| | - Takeshi Hatta
- Department of Parasitology, Kitasato University School of Medicine, 1-15-1 Kitasato, Kitasato, Minami, Sagamihara, Kanagawa 252-0374, Japan.
| | - M Abdul Alim
- Department of Parasitology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh
| | - Daigo Tsubokawa
- Department of Parasitology, Kitasato University School of Medicine, 1-15-1 Kitasato, Kitasato, Minami, Sagamihara, Kanagawa 252-0374, Japan
| | - Fusako Mikami
- Department of Parasitology, Kitasato University School of Medicine, 1-15-1 Kitasato, Kitasato, Minami, Sagamihara, Kanagawa 252-0374, Japan
| | - Kodai Kusakisako
- Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, Korimoto, 1-21-24 Korimoto, Kagoshima 890-0065, Japan; Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan
| | - Makoto Matsubayashi
- Laboratory of International Prevention of Epidemics, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Rika Umemiya-Shirafuji
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Naotoshi Tsuji
- Department of Parasitology, Kitasato University School of Medicine, 1-15-1 Kitasato, Kitasato, Minami, Sagamihara, Kanagawa 252-0374, Japan
| | - Tetsuya Tanaka
- Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, Korimoto, 1-21-24 Korimoto, Kagoshima 890-0065, Japan; Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan.
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Guerra L, Stoffolano JG, Belardinelli MC, Fausto AM. Serotonergic Innervation of the Salivary Glands and Central Nervous System of Adult Glossina pallidipes Austen (Diptera: Glossinidae), and the Impact of the Salivary Gland Hypertrophy Virus (GpSGHV) on the Host. JOURNAL OF INSECT SCIENCE (ONLINE) 2016; 16:iev162. [PMID: 26798144 PMCID: PMC4725261 DOI: 10.1093/jisesa/iev162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 12/28/2015] [Indexed: 06/05/2023]
Abstract
Using a serotonin antibody and confocal microscopy, this study reports for the first time direct serotonergic innervation of the muscle sheath covering the secretory region of the salivary glands of adult tsetse fly, Glossina pallidipes Austen. Reports to date, however, note that up until this finding, dipteran species previously studied lack a muscle sheath covering of the secretory region of the salivary glands. Direct innervation of the salivary gland muscle sheath of tsetse would facilitate rapid deployment of saliva into the host, thus delaying a host response. Our results also suggest that the neuronal and abnormal pattern seen in viral infected glands by the Glossina pallidipes salivary gland hypertrophy virus (GpSGHV) is due to a compensatory increased branching of the neurons of the salivary glands, which is associated with the increased size of the salivary glands in viral infected flies. This study shows for the first time serotonin in the cell bodies of the brain and thoracico-abdominal ganglion in adult tsetse, G. pallidipes Austen (Diptera: Glossinidae). A hypothesis is proposed as to whether innervation of the muscle sheath covering of the secretory region of the salivary glands is present in brachyceran compared with nematoceran dipterans; and, a plea is made that more research is needed to develop a blood feeding model, similar to that in the blow flies, for elucidating the various mechanisms involved in production and deployment of saliva.
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Affiliation(s)
- Laura Guerra
- Dipartimento per la Innovazioni nei sistemi Biologici, Agroalimentari e Forestali, Università degli Studi della Tuscia, Largo dell'Università snc, 01100 Viterbo, Italy (; ; ),
| | - John G Stoffolano
- Stockbridge School of Agriculture, 270 Stockbridge Rd., Fernald Hall, Room 204A, University of Massachusetts, Amherst, MA 01003, USA
| | - Maria Cristina Belardinelli
- Dipartimento per la Innovazioni nei sistemi Biologici, Agroalimentari e Forestali, Università degli Studi della Tuscia, Largo dell'Università snc, 01100 Viterbo, Italy (; ; )
| | - Anna Maria Fausto
- Dipartimento per la Innovazioni nei sistemi Biologici, Agroalimentari e Forestali, Università degli Studi della Tuscia, Largo dell'Università snc, 01100 Viterbo, Italy (; ; ),
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Rietdorf K, Blenau W, Walz B. Protein secretion in cockroach salivary glands requires an increase in intracellular cAMP and Ca2+ concentrations. JOURNAL OF INSECT PHYSIOLOGY 2005; 51:1083-91. [PMID: 16029878 DOI: 10.1016/j.jinsphys.2005.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2004] [Accepted: 05/23/2005] [Indexed: 05/03/2023]
Abstract
The salivary glands in the cockroach Periplaneta americana secrete protein-containing saliva when stimulated by serotonin (5-HT) and protein-free saliva upon dopamine stimulation. In order to obtain information concerning the signalling pathways involved in 5-HT-induced protein secretion, we have determined the protein content of saliva secreted after experimental manipulations that potentially elevate intracellular Ca2+ and cyclic nucleotide concentrations in isolated glands. We have found that 5-HT stimulates the rate of protein secretion in a dose-dependent manner (threshold: 3 x 10(-8)M; EC50 1.5 x 10(-6)M). The maximal rate of 5-HT-induced protein secretion was 2.2 +/- 0.2 microg/min. Increasing intracellular Ca2+ or cAMP by bath application of ionomycin (5 microM), db cAMP (10mM), forskolin (100 microM) or IBMX (100 microM), respectively, stimulated protein secretion at significantly lower rates, whereas db cGMP (1mM) did not activate protein secretion. The high rates and the kinetics of 5-HT-induced protein secretion could only be mimicked by either applying forskolin together with IBMX (with or without ionomycin) or by applying IBMX together with ionomycin. Our measurements suggest that 5-HT-induced protein secretion is mediated by an elevation of [cAMP]i and that Ca2+ may function as a co-agonist and augment the rate of protein secretion.
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Affiliation(s)
- K Rietdorf
- Institute of Biochemistry and Biology, Department of Animal Physiology, University of Potsdam, P.O.B. 60 15 53, 14415 Potsdam, Germany
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Zimmermann B. Subcellular organization of agonist-evoked Ca(2+) waves in the blowfly salivary gland. Cell Calcium 2000; 27:297-307. [PMID: 10859596 DOI: 10.1054/ceca.2000.0122] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We have studied the subcellular organization of intra- and intercellular Ca(2+)waves elicited by the neurohormone 5-hydroxytryptamine (5-HT) in intact blowfly salivary glands by using Ca(2+)-sensitive fluorescent probes and confocal microscopy. 5-HT (3 nM) elicited repetitive Ca(2+)waves (1) that were initiated at Ca(2+)-release sites close to the basal plasma membrane, (2) that sequentially spread to the cell apex and (3) that, after a delay of 0.7 +/- 0.20 s at the cell boundaries, spread into adjacent cells. [Ca(2+)](i)increases in the adjacent cells were first detectable at those portions of the lateral plasma membrane that faced a previously activated cell. Electron microscopy revealed that the sites of Ca(2+)wave transmission between the cells are correlated with the distribution of gap junctions that cluster in the basal cell portions. The ensuing intracellular Ca(2+)wave propagated at constant velocity (27 +/- 7.3 microm/s) in the lateral cell plane. Moreover, a basally to apically propagating wavefront was detectable at the cell membrane that bordered on the neighbor that provided the excitatory signal, whereas [Ca(2+)](i)increased simultaneously both apically and basally at the opposite lateral cell border. Overall, the subcellular patterns of Ca(2+)wave propagation differed from the patterns observed in mammalian secretory epithelial cells. The findings impose some constraints on the functional significance of intra- and intercellular Ca(2+)waves and potential mechanisms underlying 5-HT-evoked fluid secretion.
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Affiliation(s)
- B Zimmermann
- Institut für Zoophysiologie und Zellbiologie, Universität Potsdam, D-14471 Potsdam,
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Abstract
Development of a laboratory cultured tick-transmissible strain of Babesia bigemina was followed in vitro after addition of gut material from engorged female Boophilus microplus ticks and incubation at 37 degrees C. Sequential development of stages, from intraerythrocytic strahlenkörper through multiplication to the fusion of what is assumed to be two gametes, is described. A change in physical environment (temperature, gas composition) experienced during passage of Babesia stages into the in vitro culture tubes possibly mimics the changes experienced in passage from host blood to the midgut of the tick vector. The effect in vitro was to induce the erythrocytic parasites to remain inactive at a trophozoite-like stage. Addition of factor(s) within midgut initiated further development of strahlenkörper. Two populations of strahlenkörper were recognized; an elongated form which did not appear to develop further, and a polymorphic population which underwent further multiplication initiated while the parasites were still within the erythrocyte, and continuing after they had emerged. These strahlenkörper increased in size as multiple division of nuclei occurred. with cell division being completed more slowly. Large aggregations of multinucleated strahlenkorper formed, but once division was complete, single-nucleated strahlenkörper emerged from the aggregates. Two individuals of post-aggregation strahlenkörper, assumed to be gametes, fused together. The morphology and ultrastructure of all stages of development are described and compared with forms already described from the tick midgut.
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Affiliation(s)
- J M Gough
- CSIRO Tropical Agriculture, Long Pocket Laboratories, Indooroopilly, Queensland, Australia.
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Abstract
It is commonplace to think of thresholds in biological systems. Biphasic responses, with both thresholds and upper limits, or lintels, are also surprisingly common. In this paper we show that they are found in many systems in which an aspect of cellular behaviour is controlled by chemical signals. In some cases the biphasic response can lead to the partitioning of a tissue into regions expressing different behaviours and, therefore, in principle able to take different developmental and evolutionary paths within the same organism. Several other features are common; these include brief, all-or-nothing responses and the expression of different behaviours evoked by a signal of a single chemical species in one or more cell types, but over different concentration ranges. Such behaviour is illustrated very clearly by the differentiation of cells in the mammalian immune system as well as by developing slime mould cells, so the underlying principle is widespread. We suggest that the interaction of unitary behaviours with chemical signals showing such non-linear concentration dependences will account for the complexity of development.
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Affiliation(s)
- A D Robertson
- Research, Testing and Development Corporation, Lexington, Georgia 30648
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Binnington K, Lockie E, Hines E, van Gerwen A. Fine structure and distribution of three types of virus-like particles in the sheep blowfly, Lucilia cuprina and associated cytopathic effects. J Invertebr Pathol 1987. [DOI: 10.1016/0022-2011(87)90158-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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