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Vafopoulou X, Steel CGH. Halloween genes are expressed with a circadian rhythm during development in prothoracic glands of the insect RHODNIUS PROLIXUS. Comp Biochem Physiol A Mol Integr Physiol 2024; 290:111588. [PMID: 38242349 DOI: 10.1016/j.cbpa.2024.111588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/12/2024] [Accepted: 01/16/2024] [Indexed: 01/21/2024]
Abstract
We analyse the developmental and circadian profiles of expression of the genes responsible for ecdysteroidogenesis (Halloween genes) in the PGs of Rhodnius prolixus throughout larval-adult development. Extensive use of in vitro techniques enabled multiple different parameters to be measured in individual PGs. Expression of disembodied and spook closely paralleled the ecdysteroid synthesis of the same PGs, and the ecdysteroid titre in vivo, but with functionally significant exceptions. Various tissues other than PGs expressed one, both or neither genes. Both gonads express both genes in pharate adults (larvae close to ecdysis). Both genes were expressed at low, but significant, levels in UF Rhodnius, raising questions concerning how developmental arrest is maintained in UF animals. IHC confirmed the subcellular localisation of the coded proteins. Gene knockdown suppressed transcription of both genes and ecdysteroid synthesis, with spook apparently regulating the downstream gene disembodied. Transcription of both genes occurred with a daily rhythm (with peaks at night) that was confirmed to be under circadian control using aperiodic conditions. The complex behaviour of the rhythm in LL implied two anatomically distinct oscillators regulate this transcription rhythm. First, the circadian clock in the PGs and second, the circadian rhythm of of Rhodnius PTTH which is released rhythmically from the brain under control of the circadian clock therein, both of which were described previously. We conclude ecdysteroidogenesis in Rhodnius PGs employs a similar pathway as other insects, but its control is complex, involving mechanisms both within and outside the PGs.
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Affiliation(s)
| | - Colin G H Steel
- Department of Biology, York University, Toronto M3J 1P3, Canada.
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2
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Botzotz J, Méndez-Valdés G, Ortiz S, López A, Botto-Mahan C, Solari A. Natural Trypanosoma cruzi Infection and Climatic Season Influence the Developmental Capacity in Field-Caught Mepraia spinolai Nymphs. INSECTS 2023; 14:272. [PMID: 36975957 PMCID: PMC10058416 DOI: 10.3390/insects14030272] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
In this study, we evaluated the effect of the climatic season and infection by Trypanosoma cruzi, etiological agent of Chagas disease, on the molting capacity of the triatomine vector Mepraia spinolai endemic to Chile. We used wild-caught first-to-fourth instar nymphs during cooling (fall and winter) and warming (spring) periods. After capturing, nymphs were fed at the laboratory, and maintained under optimal rearing conditions. Feeding was repeated 40 days later. We followed-up the molting events on 709 nymphs, recording one, two or the absence of molts after two feeding opportunities. Within the same climatic period, only infected second- and fourth-instar nymphs from the warming period showed a larger proportion of double molting compared to uninfected nymphs. Regarding the climatic period, infected and uninfected first- and fourth-instar nymphs exhibited a larger proportion of double molting in the warming and cooling periods, respectively. The pattern of non-molting nymph occurrence suggests they probably reach diapause by environmental stochasticity. The effect of the climatic period and T. cruzi infection on the development of M. spinolai is an instar-dependent phenomenon, highlighting the occurrence of finely synchronized processes at different moments of the life cycle of such an hemimetabolous insect as triatomines.
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Affiliation(s)
- Juan Botzotz
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380000, Chile
| | - Gabriel Méndez-Valdés
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380000, Chile
| | - Sylvia Ortiz
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380000, Chile
| | - Angélica López
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380000, Chile
| | - Carezza Botto-Mahan
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile
| | - Aldo Solari
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380000, Chile
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3
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Guirado J, Carranza-Valencia J, Morante J. Mammalian puberty: a fly perspective. FEBS J 2023; 290:359-369. [PMID: 35607827 PMCID: PMC10084137 DOI: 10.1111/febs.16534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 05/02/2022] [Accepted: 05/23/2022] [Indexed: 02/05/2023]
Abstract
Mammalian puberty and Drosophila metamorphosis, despite their evolutionary distance, exhibit similar design principles and conservation of molecular components. In this Viewpoint, we review recent advances in this area and the similarities between both processes in terms of the signaling pathways and neuroendocrine circuits involved. We argue that the detection and uptake of peripheral fat by Drosophila prothoracic endocrine cells induces endomembrane remodeling and ribosomal maturation, leading to the acquisition of high biosynthetic and secretory capacity. The absence of this fat-neuroendocrine interorgan communication leads to giant, obese, non-pupating larvae. Importantly, human leptin is capable of signaling the pupariation process in Drosophila, and its expression prevents obesity and triggers maturation in mutants that do not pupate. This implies that insect metamorphosis can be used to address issues related to the biology of leptin and puberty.
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Affiliation(s)
- Juan Guirado
- Instituto de Neurociencias, Consejo Superior de Investigaciones Cientificas (CSIC) and Universidad Miguel Hernández (UMH), San Juan de Alicante, Spain
| | - Juan Carranza-Valencia
- Instituto de Neurociencias, Consejo Superior de Investigaciones Cientificas (CSIC) and Universidad Miguel Hernández (UMH), San Juan de Alicante, Spain
| | - Javier Morante
- Instituto de Neurociencias, Consejo Superior de Investigaciones Cientificas (CSIC) and Universidad Miguel Hernández (UMH), San Juan de Alicante, Spain
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4
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Ahmadi F, Mikani A, Moharramipour S. Induction of diapause by clock proteins period and timeless via changes in PTTH and ecdysteroid titer in the sugar beet moth, Scrobipalpa ocellatella (Lepidoptera: Gelechiidae). ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2021; 107:e21790. [PMID: 33860953 DOI: 10.1002/arch.21790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/05/2021] [Accepted: 03/27/2021] [Indexed: 06/12/2023]
Abstract
The sugar beet moth, Scrobipalpa ocellatella (Boyd), one of the most severe sugar beet pests, causes quantitative and qualitative yield losses late in the autumn. Previously, it was shown that low temperature and short-day photoperiod together cause diapause induction in pupae. Here, the interaction of the critical elements of the diapause induction, including the period (PER), timeless (TIM), prothoracicotropic hormone (PTTH), and ecdysteroid titer, were investigated. Immunohistochemistry results showed that the number of period immunoreactivity (PER-ir) and TIM-ir cells in nondiapause pupae (NDP) was lower than in the brain of the diapause pupae (DP). Moreover, the number of PER-ir and TIM-ir cells in the protocerebrum and optic lobe (OL) of NDP was lower than DP. Moreover, lower PTTH content in the brain and hemolymph of DP was confirmed by competitive enzyme-linked immunosorbent assay. Enzyme immunoassay showed a lower 20-hydroxyecdysone (20E) titer in the hemolymph of the DP compared with the NDP. Within a short-day condition, PER and TIM titers increased in the brain leading to decreasing PTTH titers in the brain and hemolymph that caused decreasing 20E titer in the hemolymph, leading to the induction of diapause. This study suggests that PER and TIM could be one of the brain factors that play an essential role in regulating diapause in S. ocellatella.
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Affiliation(s)
- Fatemeh Ahmadi
- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
| | - Azam Mikani
- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
| | - Saeid Moharramipour
- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
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5
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Piszter G, Kertész K, Horváth ZE, Bálint Z, Biró LP. Reproducible phenotype alteration due to prolonged cooling of the pupae of Polyommatus icarus butterflies. PLoS One 2019; 14:e0225388. [PMID: 31765404 PMCID: PMC6876796 DOI: 10.1371/journal.pone.0225388] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/15/2019] [Indexed: 12/22/2022] Open
Abstract
The phenotypic changes induced by prolonged cooling (2-12 weeks at 5 °C in the dark) of freshly formed Polyommatus icarus pupae were investigated. Cooling halted the imaginal development of pupae collected shortly after transformation from the larval stage. After cooling, the pupae were allowed to continue their developmental cycle. The wings of the eclosed specimens were investigated by optical microscopy, scanning and cross-sectional transmission electron microscopy, UV-VIS spectroscopy and microspectroscopy. The eclosed adults presented phenotypic alterations that reproduced results that we published previously for smaller groups of individuals remarkably well; these changes included i) a linear increase in the magnitude of quantified deviation from normal ventral wing patterns with increasing cooling time; ii) slight alteration of the blue coloration of males; and iii) an increasing number of blue scales on the dorsal wing surface of females with increasing cooling time. Several independent factors, including disordering of regular scale rows in males, the number of blue scales in females, eclosion probability and the probability of defect-free eclosion, showed that the cooling time can be divided into three periods: 0-4 weeks, 4-8 weeks, and 8-12 weeks, each of which is characterized by specific changes. The shift from brown female scales to first blue scales with a female-specific shape and then to blue scales with a male-specific shape with longer cooling times suggests slow decomposition of a substance governing scale formation.
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Affiliation(s)
- Gábor Piszter
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest, Hungary
| | - Krisztián Kertész
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest, Hungary
| | - Zsolt Endre Horváth
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest, Hungary
| | - Zsolt Bálint
- Hungarian Natural History Museum, Budapest, Hungary
| | - László Péter Biró
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest, Hungary
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6
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Stroppa MM, García BA. Clock Gene Timeless in the Chagas Disease Vector Triatoma infestans (Hemiptera: Reduviidae). Am J Trop Med Hyg 2019; 101:1369-1372. [PMID: 31595862 DOI: 10.4269/ajtmh.19-0169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
To contribute to a better understanding of the molecular basis of the circadian biological rhythms in Chagas disease vectors, in this work we identified functional domains in the sequences of the clock protein TIMELESS (TIM) in Rhodnius prolixus and analyzed the expression of the timeless (tim) gene at the mRNA level in Triatoma infestans. The tim gene expression in nervous tissue of adult T. infestans revealed clear oscillations in the abundance of the transcript in both sexes in the group maintained under photoperiod with a daily canonical rhythm, showing a significant increase in expression at sunset. As expected, in the group maintained in constant light, no daily increase was detected in the tim transcript level.
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Affiliation(s)
- María M Stroppa
- Instituto de Investigaciones en Ciencias de la Salud (INICSA), CONICET and Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Beatriz A García
- Instituto de Investigaciones en Ciencias de la Salud (INICSA), CONICET and Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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Adamo SA. Turning your victim into a collaborator: exploitation of insect behavioral control systems by parasitic manipulators. CURRENT OPINION IN INSECT SCIENCE 2019; 33:25-29. [PMID: 31358191 DOI: 10.1016/j.cois.2019.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 01/05/2019] [Accepted: 01/08/2019] [Indexed: 06/10/2023]
Abstract
Some parasites manipulate host behavior by exploiting the host's behavioral control networks. This review explores two examples of this approach using parasites from opposite ends of the size spectrum, that is, viruses and parasitic insects. The first example explores the use of the gene (egt) by some baculoviruses to deactivate the hormone 20-hydroxyecdysone. Suppressing this chemical signal prevents the expression of behaviors that could reduce viral transmission. The second example explores how a parasitic wasp uses the host's immune/neural communication system to control host behavior. When a host's manipulated behavior requires complex neural coordination, exploitation of host behavioral control systems is likely to be involved. Simpler host behaviors can be induced by damage to host tissues.
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Affiliation(s)
- Shelley A Adamo
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, B3H4R2, Canada.
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8
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Stroppa MM, Gimenez I, García BA. Clock Gene Period in the Chagas Disease Vector Triatoma infestans (Hemiptera: Reduviidae). Am J Trop Med Hyg 2018; 98:468-474. [PMID: 29260645 PMCID: PMC5929179 DOI: 10.4269/ajtmh.17-0147] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 10/31/2017] [Indexed: 11/07/2022] Open
Abstract
To contribute to a better understanding of the molecular bases of the circadian biological rhythms in Chagas disease vectors, in this work we identified functional domains in the sequences of the clock protein PERIOD (PER) in Rhodnius prolixus and Triatoma infestans and analyzed the expression of the PER gene at mRNA level in T. infestans. The PER protein sequences comparison among these species and those from other insects revealed that the most similar regions are the PAS domains and the most variable is the COOH-terminal. On the other hand, the per gene expression in nervous tissue of adult T. infestans varies with a daily canonical rhythm in groups of individuals maintained under photoperiod (light/dark, LD) and constant dark (DD), showing a significant peak of expression at sunset. The pattern of expression detected in LD persists under the DD condition. As expected, in the group maintained in constant light (LL), no daily increase was detected in per transcript level. Besides, the presence of per transcript in different tissues of adult individuals and in nervous tissue of nymphs evidenced activity of peripheral clocks in adults and activity of the central clock in nymphs of T. infestans.
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Affiliation(s)
- María M. Stroppa
- Instituto de Investigaciones en Ciencias de la Salud (INICSA), CONICET and Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Ignacio Gimenez
- Instituto de Investigaciones en Ciencias de la Salud (INICSA), CONICET and Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Beatriz A. García
- Instituto de Investigaciones en Ciencias de la Salud (INICSA), CONICET and Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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9
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Collantes-Alegre JM, Mattenberger F, Barberà M, Martínez-Torres D. Characterisation, analysis of expression and localisation of the opsin gene repertoire from the perspective of photoperiodism in the aphid Acyrthosiphon pisum. JOURNAL OF INSECT PHYSIOLOGY 2018; 104:48-59. [PMID: 29203177 DOI: 10.1016/j.jinsphys.2017.11.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/19/2017] [Accepted: 11/30/2017] [Indexed: 06/07/2023]
Abstract
Organisms exhibit a wide range of seasonal responses as adaptions to predictable annual changes in their environment. These changes are originally caused by the effect of the Earth's cycles around the sun and its axial tilt. Examples of seasonal responses include floration, migration, reproduction and diapause. In temperate climate zones, the most robust variable to predict seasons is the length of the day (i.e. the photoperiod). The first step to trigger photoperiodic driven responses involves measuring the duration of the light-dark phases, but the molecular clockwork performing this task is poorly characterized. Photopigments such as opsins are known to participate in light perception, being part of the machinery in charge of providing information about the luminous state of the surroundings. Aphids (Hemiptera: Aphididae) are paradigmatic photoperiodic insects, exhibiting a strong induction to diapause when the light regime mimics autumn conditions. The availability of the pea aphid (Acyrthosiphon pisum) genome has facilitated molecular approaches to understand the effect of light stimulus in the photoperiodic induction process. We have identified, experimentally validated and characterized the expression of the full opsin gene repertoire in the pea aphid. Among identified opsin genes in A. pisum, arthropsin is absent in most insects sequenced to date (except for dragonflies and two other hemipterans) but also present in a crustacean, an onychophoran and chelicerates. We have quantified the expression of these genes in aphids exposed to different photoperiodic conditions and at different times of the day and localized their transcripts in the aphid brain. Clear differences in expression patterns were found, thus relating opsin expression with the photoperiodic response.
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Affiliation(s)
- Jorge Mariano Collantes-Alegre
- Institut de Biologia Integrativa de Sistemes, Parc Científic Universitat de València, C/Catedrático José Beltrán n° 2, 46980 Paterna, València, Spain
| | - Florian Mattenberger
- Institut de Biologia Integrativa de Sistemes, Parc Científic Universitat de València, C/Catedrático José Beltrán n° 2, 46980 Paterna, València, Spain; Department of Abiotic Stress, Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, Valencia 46022, Spain
| | - Miquel Barberà
- Institut de Biologia Integrativa de Sistemes, Parc Científic Universitat de València, C/Catedrático José Beltrán n° 2, 46980 Paterna, València, Spain
| | - David Martínez-Torres
- Institut de Biologia Integrativa de Sistemes, Parc Científic Universitat de València, C/Catedrático José Beltrán n° 2, 46980 Paterna, València, Spain.
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Barberà M, Martínez-Torres D. Identification of the prothoracicotropic hormone (Ptth) coding gene and localization of its site of expression in the pea aphid Acyrthosiphon pisum. INSECT MOLECULAR BIOLOGY 2017; 26:654-664. [PMID: 28677913 DOI: 10.1111/imb.12326] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Insect hormones control essential aspects of physiology, behaviour and development in insects. The majority of insect hormones are peptide hormones that perform a highly diverse catalogue of functions. Prothoracicotropic hormone (PTTH) is a brain neuropeptide hormone whose main function is to stimulate the secretion of ecdysone (the moulting hormone) by the prothoracic glands in insect larvae thus playing a key role in the control of moulting and metamorphosis. Moreover, both PTTH release or blockade have been reported to act as a switch to terminate or initiate larval and pupal diapauses. In insects, diapause is a prevalent response often regulated by the photoperiod. It has been shown that PTTH participates as an output of the circadian clock and a role in photoperiodic processes is suggested in some insect species. Aphids (Hemiptera: Aphididae) reproduce by cyclical parthenogenesis with a sexual phase, induced by short photoperiods, that leads to the production of diapausing eggs. With the availability of the pea aphid (Acyrthosiphon pisum) genome, efforts to identify and characterize genes relevant to essential aspects of aphid biology have multiplied. In spite of its relevance, several genomic and transcriptomic studies on aphid neuropeptides failed to detect aphid PTTH amongst them. Here we report on the first identification of the aphid PTTH coding gene and the neuroanatomical localization of its expression in the aphid brain.
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Affiliation(s)
- M Barberà
- Institut de Biologia Integrativa de Sistemes & Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Parc Cientific Universitat de Valencia, Paterna, València, Spain
| | - D Martínez-Torres
- Institut de Biologia Integrativa de Sistemes & Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Parc Cientific Universitat de Valencia, Paterna, València, Spain
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11
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Ons S. Neuropeptides in the regulation of Rhodnius prolixus physiology. JOURNAL OF INSECT PHYSIOLOGY 2017; 97:77-92. [PMID: 27210592 DOI: 10.1016/j.jinsphys.2016.05.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 04/19/2016] [Accepted: 05/18/2016] [Indexed: 06/05/2023]
Abstract
In the kissing bug Rhodnius prolixus, events such as diuresis, antidiuresis, development and reproduction are triggered by blood feeding. Hence, these events can be accurately timed, facilitating physiological experiments. This, combined with its relatively big size, makes R. prolixus an excellent model in insect neuroendocrinological studies. The importance of R. prolixus as a Chagas' disease vector as much as an insect model has motivated the sequencing of its genome in recent years, facilitating genetic and molecular studies. Most crucial physiological processes are regulated by the neuroendocrine system, composed of neuropeptides and their receptors. The identification and characterization of neuropeptides and their receptors could be the first step to find targets for new insecticides. The sequences of 41 neuropeptide precursor genes and the receptors for most of them were identified in the R. prolixus genome. Functional information about many of these molecules was obtained, whereas many neuroendocrine systems are still unstudied in this model species. This review addresses the knowledge available to date regarding the structure, distribution, expression and physiological effects of neuropeptides in R. prolixus, and points to future directions in this research field.
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Affiliation(s)
- Sheila Ons
- Laboratory of Insects Neurobiology, National Center for Genomic Studies, Faculty of Exact Sciences, National University of La Plata, Bvd 120 1459, La Plata, Buenos Aires, Argentina.
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12
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Wulff JP, Sierra I, Sterkel M, Holtof M, Van Wielendaele P, Francini F, Broeck JV, Ons S. Orcokinin neuropeptides regulate ecdysis in the hemimetabolous insect Rhodnius prolixus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 81:91-102. [PMID: 28089691 DOI: 10.1016/j.ibmb.2017.01.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 12/14/2016] [Accepted: 01/04/2017] [Indexed: 06/06/2023]
Abstract
To grow and develop insects must undergo ecdysis. During this process, the individual sheds the old cuticle to emerge as the following developmental stage. During ecdysis, different programed behaviors are regulated by neuropeptidergic pathways. In general, components of these pathways are better characterized in crustacean and holometabolous insects than in hemimetabola. In insects, the orkoninin gene produces two different neuropeptide precursors by alternative splicing: orcokinin A and orcokinin B. Although orcokinins are well conserved in insect species, their physiological role remains elusive. Here we describe a new splicing variant of the orcokinin gene in the hemimetabolous triatomine Rhodnius prolixus. We further analyze the expression pattern and the function of the alternatively spliced RhoprOK transcripts by means of immunohistochemistry and RNAi-mediated gene silencing. Our results indicate that orkoninis play an essential role in the peptidergic signaling pathway regulating ecdysis in the hemimetabolous insect Rhodnius prolixus.
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Affiliation(s)
- Juan Pedro Wulff
- Laboratory of Genetics and Functional Genomics, Regional Center for Genomic Studies, Faculty of Exact Sciences, National University of La Plata, Bvd 120 y 62, 1900, La Plata, Buenos Aires, Argentina.
| | - Ivana Sierra
- Laboratory of Genetics and Functional Genomics, Regional Center for Genomic Studies, Faculty of Exact Sciences, National University of La Plata, Bvd 120 y 62, 1900, La Plata, Buenos Aires, Argentina.
| | - Marcos Sterkel
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, bloco D, Prédio do CCS, Ilha do Fundão, Rio de Janeiro, 21941-902, Brazil.
| | - Michiel Holtof
- Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Zoological Institute, K.U. Leuven, Leuven, Belgium.
| | - Pieter Van Wielendaele
- Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Zoological Institute, K.U. Leuven, Leuven, Belgium.
| | - Flavio Francini
- Centre of Experimental and Applied Endocrinology, National University of La Plata, School of Medicine, 60 Street y 120, 1900, La Plata, Buenos Aires, Argentina.
| | - Jozef Vanden Broeck
- Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Zoological Institute, K.U. Leuven, Leuven, Belgium.
| | - Sheila Ons
- Laboratory of Genetics and Functional Genomics, Regional Center for Genomic Studies, Faculty of Exact Sciences, National University of La Plata, Bvd 120 y 62, 1900, La Plata, Buenos Aires, Argentina.
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Subala SP, Shivakumar MS. Circadian variation affects the biology and digestive profiles of a nocturnal insectSpodoptera litura(Insecta: Lepidoptera). BIOL RHYTHM RES 2016. [DOI: 10.1080/09291016.2016.1251928] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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14
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Cardinal-Aucoin M, Steel CGH. Circadian control of prothoracicotropic hormone release in an adult insect and the induction of its rhythmicity by light cues. Comp Biochem Physiol A Mol Integr Physiol 2016; 201:46-52. [PMID: 27371111 DOI: 10.1016/j.cbpa.2016.06.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 06/23/2016] [Accepted: 06/23/2016] [Indexed: 11/19/2022]
Abstract
The insect neuropeptide prothoracicotropic hormone (PTTH) is a critical regulator of larval development. We recently demonstrated that PTTH is also present in adult Rhodnius prolixus and is released by adult brains in vitro with a clear daily rhythm during egg development. Here, we employ a well-established in vitro bioassay, to show that the daily rhythm of PTTH release by brains in vitro is under circadian control since it persists in aperiodic conditions with a free running period of around 24h that is temperature compensated. Prolonged exposure (3weeks) of insects to continuous constant light (LL) completely eliminated PTTH release. Subsequent transfer of such insects from LL to constant darkness (DD) rapidly induced rhythmic PTTH release, indicating that the circadian rhythm of PTTH release is induced by photic cues. Western analysis identified PTTH in the adult hemolymph, suggesting that PTTH acts as a functional neurohormone in the adult insect. Dot blot analysis revealed that PTTH levels in the hemolymph also cycled with a daily rhythm that persisted in DD and was synchronous with the rhythm of PTTH release by brains in vitro. We conclude that the previously documented photosensitive clock in the brain regulates rhythmic PTTH release and thus generates the rhythm seen in the hemolymph. These results emphasize the importance of rhythmic PTTH release in the adult insect and support a role for PTTH in adult physiology and possibly within the adult circadian system.
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Affiliation(s)
| | - Colin G H Steel
- Department of Biology, York University, 4700 Keele St., Toronto, ON M3J 1P3, Canada
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Jenni S, Goyal Y, von Grotthuss M, Shvartsman SY, Klein DE. Structural Basis of Neurohormone Perception by the Receptor Tyrosine Kinase Torso. Mol Cell 2015; 60:941-52. [PMID: 26698662 DOI: 10.1016/j.molcel.2015.10.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 09/17/2015] [Accepted: 10/14/2015] [Indexed: 10/22/2022]
Abstract
In insects, brain-derived Prothoracicotropic hormone (PTTH) activates the receptor tyrosine kinase (RTK) Torso to initiate metamorphosis through the release of ecdysone. We have determined the crystal structure of silkworm PTTH in complex with the ligand-binding region of Torso. Here we show that ligand-induced Torso dimerization results from the sequential and negatively cooperative formation of asymmetric heterotetramers. Mathematical modeling of receptor activation based upon our biophysical studies shows that ligand pulses are "buffered" at low receptor levels, leading to a sustained signal. By contrast, high levels of Torso develop the signal intensity and duration of a noncooperative system. We propose that this may allow Torso to coordinate widely different functions from a single ligand by tuning receptor levels. Phylogenic analysis indicates that Torso is found outside arthropods, including human parasitic roundworms. Together, our findings provide mechanistic insight into how this receptor system, with roles in embryonic and adult development, is regulated.
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Affiliation(s)
- Simon Jenni
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Yogesh Goyal
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | | | - Stanislav Y Shvartsman
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Daryl E Klein
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Division of Molecular Medicine, Children's Hospital, Boston, MA 02115, USA.
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Villalobos-Sambucaro MJ, Lorenzo-Figueiras AN, Riccillo FL, Diambra LA, Noriega FG, Ronderos JR. Allatotropin modulates myostimulatory and cardioacceleratory activities in Rhodnius prolixus (Stal). PLoS One 2015; 10:e0124131. [PMID: 25897783 PMCID: PMC4405368 DOI: 10.1371/journal.pone.0124131] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 03/10/2015] [Indexed: 11/22/2022] Open
Abstract
Haematophagous insects can ingest large quantities of blood in a single meal and eliminate high volumes of urine in the next few hours. This rise in diuresis is possible because the excretory activity of the Malpighian tubules is facilitated by an increase in haemolymph circulation as a result of intensification of aorta contractions combined with an increase of the anterior midgut peristaltic waves. It has been previously described that haemolymph circulation during post-prandial diuresis is stimulated by the synergistic activity of allatotropin (AT) and serotonin in the kissing bug Triatoma infestans; resulting in an increase in aorta contractions. In the same species, AT stimulates anterior midgut and rectum muscle contractions to mix urine and feces and facilitate the voiding of the rectum. Furthermore, levels of AT in midgut and Malpighian tubules increased in the afternoon when insects are getting ready for nocturnal feeding. In the present study we describe the synergistic effect of AT and serotonin increasing the frequency of contractions of the aorta in Rhodnius prolixus. The basal frequency of contractions of the aorta in the afternoon is higher that the observed during the morning, suggesting the existence of a daily rhythmic activity. The AT receptor is expressed in the rectum, midgut and dorsal vessel, three critical organs involved in post-prandial diuresis. All together these findings provide evidence that AT plays a role as a myoregulatory and cardioacceleratory peptide in R. prolixus.
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Affiliation(s)
- María José Villalobos-Sambucaro
- Cátedra Histología y Embriología Animal (FCNyM-UNLP), La Plata, Argentina
- Centro Regional de Estudios Genómicos (CREG-UNLP), La Plata, Argentina
| | | | - Fernando Luis Riccillo
- Cátedra Histología y Embriología Animal (FCNyM-UNLP), La Plata, Argentina
- Centro Regional de Estudios Genómicos (CREG-UNLP), La Plata, Argentina
| | | | - Fernando Gabriel Noriega
- Department of Biological Sciences, Florida International University, Miami, Florida, United States of America
| | - Jorge Rafael Ronderos
- Cátedra Histología y Embriología Animal (FCNyM-UNLP), La Plata, Argentina
- Centro Regional de Estudios Genómicos (CREG-UNLP), La Plata, Argentina
- * E-mail:
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Lazzari CR, Pereira MH, Lorenzo MG. Behavioural biology of Chagas disease vectors. Mem Inst Oswaldo Cruz 2014; 108 Suppl 1:34-47. [PMID: 24473801 PMCID: PMC4109178 DOI: 10.1590/0074-0276130409] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 10/07/2013] [Indexed: 11/21/2022] Open
Abstract
Many arthropod species have adopted vertebrate blood as their main food source. Blood
is rich in nutrients and, except for the presence of parasites, sterile. However,
this food source is not freely available, nor is obtaining it devoid of risk. It
circulates inside vessels hidden underneath the skin of mobile hosts that are able to
defend themselves and even predate the insects that try to feed on them. Thus, the
haematophagous lifestyle is associated with major morphological, physiological and
behavioural adaptations that have accumulated throughout the evolutionary history of
the various lineages of blood-sucking arthropods. These adaptations have significant
consequences for the evolution of parasites as well as for the epidemiology of
vector-transmitted diseases. In this review article, we analyse various aspects of
the behaviour of triatomine bugs to illustrate how each behavioural trait represents
a particular adaptation to their close association with their hosts, which may easily
turn into predators. Our aim is to offer to the reader an up-to-date integrative
perspective on the behaviour of Chagas disease vectors and to propose new research
avenues to encourage both young and experienced colleagues to explore this aspect of
triatomine biology.
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Affiliation(s)
- Claudio Ricardo Lazzari
- Institut de Recherche sur la Biologie de l'Insecte, Unité Mixte de Recherche 7261, Centre National de la Recherche Scientifique, Université François Rabelais de Tours, France, ToursIndre et Loire, Institut de Recherche sur la Biologie de l'Insecte, Unité Mixte de Recherche 7261, Centre National de la Recherche Scientifique, Université François Rabelais de Tours, Tours, Indre et Loire, France
| | - Marcos Horácio Pereira
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Brasil, Belo HorizonteMG, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil
| | - Marcelo Gustavo Lorenzo
- Centro de Pesquisa René Rachou, Fiocruz, Brasil, Belo HorizonteMG, Centro de Pesquisa René Rachou-Fiocruz, Belo Horizonte, MG, Brasil
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18
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Meireles-Filho ACA, Kyriacou CP. Circadian rhythms in insect disease vectors. Mem Inst Oswaldo Cruz 2014; 108 Suppl 1:48-58. [PMID: 24473802 PMCID: PMC4109179 DOI: 10.1590/0074-0276130438] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 11/12/2013] [Indexed: 01/16/2023] Open
Abstract
Organisms from bacteria to humans have evolved under predictable daily environmental
cycles owing to the Earth’s rotation. This strong selection pressure has generated
endogenous circadian clocks that regulate many aspects of behaviour, physiology and
metabolism, anticipating and synchronising internal time-keeping to changes in the
cyclical environment. In haematophagous insect vectors the circadian clock
coordinates feeding activity, which is important for the dynamics of pathogen
transmission. We have recently witnessed a substantial advance in molecular studies
of circadian clocks in insect vector species that has consolidated behavioural data
collected over many years, which provided insights into the regulation of the clock
in the wild. Next generation sequencing technologies will facilitate the study of
vector genomes/transcriptomes both among and within species and illuminate some of
the species-specific patterns of adaptive circadian phenotypes that are observed in
the field and in the laboratory. In this review we will explore these recent findings
and attempt to identify potential areas for further investigation.
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Affiliation(s)
- Antonio Carlos Alves Meireles-Filho
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Switzerland, Lausanne, Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Charalambos Panayiotis Kyriacou
- Department of Genetics, University of Leicester, UK, Leicester, Department of Genetics, University of Leicester, Leicester, UK
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Fresquet N, Lazzari CR. Daily variation of the response to heat in Rhodnius prolixus: the roles of light and temperature as synchronisers. JOURNAL OF INSECT PHYSIOLOGY 2014; 70:36-40. [PMID: 25200474 DOI: 10.1016/j.jinsphys.2014.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 08/26/2014] [Accepted: 08/28/2014] [Indexed: 06/03/2023]
Abstract
Triatominae are blood-sucking insects that localise their hosts with their multimodal host associated perceptive signals. Among that sensory information, one of the main short-range cue is heat which, even in isolation, is able to trigger the Proboscis Extension Response (PER) preceding the bite. Previous studies have demonstrated a rhythmic variation of the response to host signals compatible with the nocturnal habits of triatomine insects. This study was aimed at determining whether the PER to heat was also modulated by a daily variation and, if so, if it was an endogenous or exogenous rhythm. We also investigated what was used as a synchroniser between light and temperature. The results showed that alternation of light and darkness was required to ensure a high level of responsiveness to heat in early scotophase while the temperature cycle appeared with a weaker synchronisation power. We concluded that the responsiveness to heat was an exogenous rhythm synchronised by a complementary control of light and temperature cycles. The involvement of two synchronisers hierarchically organised might have increased the plasticity of the host-seeking behaviour to cope with environmental conditions.
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Affiliation(s)
- Nadine Fresquet
- Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 7261, Université François Rabelais, Tours, France.
| | - Claudio R Lazzari
- Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 7261, Université François Rabelais, Tours, France
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Vafopoulou X, Steel CGH. Synergistic induction of the clock protein PERIOD by insulin-like peptide and prothoracicotropic hormone in Rhodnius prolixus (Hemiptera): implications for convergence of hormone signaling pathways. Front Physiol 2014; 5:41. [PMID: 24600396 PMCID: PMC3928625 DOI: 10.3389/fphys.2014.00041] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 01/22/2014] [Indexed: 12/01/2022] Open
Abstract
We showed previously that release of the cerebral neurohormones, bombyxin (an insulin-like peptide, ILP) and prothoracicotropic hormone (PTTH) from the brain have strong circadian rhythms, driven by master clock cells in the brain. These neurohormone rhythms synchronize the photosensitive brain clock with the photosensitive peripheral clock in the cells of the prothoracic glands (PGs), in which both regulate steroidogenesis. Here, using immunohistochemistry and confocal laser scanning microscopy, we show these neurohormones likely act on clock cells in the brain and PGs by regulating expression of PERIOD (PER) protein. PER is severely reduced in the nuclei of all clock cells in continuous light, but on transfer of tissues to darkness in vitro, it is rapidly induced. A 4h pulse of either PTTH or ILPs to brain and PGs in vitro both rapidly and highly significantly induce PER in the nuclei of clock cells. Administration of both neurohormones together induces more PER than does either alone and even more than does transfer to darkness, at least in PG cells. These are clearly non-steroidogenic actions of these peptides. In the peripheral oscillators salivary gland (SG) and fat body cells, neither bombyxin nor PTTH nor darkness induced PER, but a combination of both bombyxin and PTTH induced PER. Thus, PTTH and ILPs exert synergistic actions on induction of PER in both clock cells and peripheral oscillators, implying their signaling pathways converge, but in different ways in different cell types. We infer clock cells are able to integrate light cycle information with internal signals from hormones.
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Characterization of Rab-interacting lysosomal protein in the brain of Bombyx mori. Histochem Cell Biol 2013; 141:311-20. [PMID: 24190830 DOI: 10.1007/s00418-013-1160-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/15/2013] [Indexed: 10/26/2022]
Abstract
Rab guanosine triphosphatases in eukaryotic cells are key regulators of membrane-trafficking events, such as exocytosis and endocytosis. Rab7 regulates traffic from early to late endosomes and from late endosomes to vacuoles/lysosomes. The Rab7-interacting lysosomal protein (RILP) was extracted from the silkworm, Bombyx mori (B. mori), and expressed in Escherichia coli (E. coli), followed by its purification. The glutathione sulfotransferase pull-down assay revealed that Rab7 of B. mori interacted with RILP of B. mori. We then produced antibodies against RILP of B. mori in rabbits for their use in Western immunoblotting and immunohistochemistry. Western immunoblotting of brain tissue for RILP revealed a single band, at approximately 50 kD. RILP-like immunohistochemical reactivity (RILP-ir) was restricted to neurons of the pars intercerebralis and dorsolateral protocerebrum. Furthermore, RILP-ir was colocalized with the eclosion hormone-ir and bombyxin-ir. However, RILP-ir was not colocalized with prothoracicotropic hormone-ir. These results were similar to those of Rab7 from our previous study. These findings suggest that RILP and Rab7 are involved in the neurosecretion in a restricted subtype of neurons in B. mori. Thus, our study is the first to report of a possible relationship between an insect Rab effector and neurosecretion.
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Cardinal-Aucoin M, Rapp N, Steel CG. Circadian regulation of hemolymph and ovarian ecdysteroids during egg development in the insect Rhodnius prolixus (Hemiptera). Comp Biochem Physiol A Mol Integr Physiol 2013; 166:503-9. [DOI: 10.1016/j.cbpa.2013.08.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 08/05/2013] [Accepted: 08/06/2013] [Indexed: 11/24/2022]
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Flatt T, Amdam GV, Kirkwood TBL, Omholt SW. Life-history evolution and the polyphenic regulation of somatic maintenance and survival. QUARTERLY REVIEW OF BIOLOGY 2013; 88:185-218. [PMID: 24053071 DOI: 10.1086/671484] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Here we discuss life-history evolution from the perspective of adaptive phenotypic plasticity, with a focus on polyphenisms for somatic maintenance and survival. Polyphenisms are adaptive discrete alternative phenotypes that develop in response to changes in the environment. We suggest that dauer larval diapause and its associated adult phenotypes in the nematode (Caenorhabditis elegans), reproductive dormancy in the fruit fly (Drosophila melanogaster) and other insects, and the worker castes of the honey bee (Apis mellifera) are examples of what may be viewed as the polyphenic regulation of somatic maintenance and survival. In these and other cases, the same genotype can--depending upon its environment--express either of two alternative sets of life-history phenotypes that differ markedly with respect to somatic maintenance, survival ability, and thus life span. This plastic modulation of somatic maintenance and survival has traditionally been underappreciated by researchers working on aging and life history. We review the current evidence for such adaptive life-history switches and their molecular regulation and suggest that they are caused by temporally and/or spatially varying, stressful environments that impose diversifying selection, thereby favoring the evolution of plasticity of somatic maintenance and survival under strong regulatory control. By considering somatic maintenance and survivorship from the perspective of adaptive life-history switches, we may gain novel insights into the mechanisms and evolution of aging.
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Affiliation(s)
- Thomas Flatt
- Institut für Populationsgenetik, Vetmeduni Vienna, A-1210 Vienna, Austria.
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Bajgar A, Dolezel D, Hodkova M. Endocrine regulation of non-circadian behavior of circadian genes in insect gut. JOURNAL OF INSECT PHYSIOLOGY 2013; 59:881-6. [PMID: 23811190 DOI: 10.1016/j.jinsphys.2013.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 06/07/2013] [Accepted: 06/10/2013] [Indexed: 05/11/2023]
Abstract
The linden bug Pyrrhocoris apterus exhibits a robust diapause response to photoperiod. Photoperiod strongly affected basal levels of circadian gene transcripts in the gut, via the neuroendocrine system. Cryptochrome 2 (cry2) mRNA level was much higher in diapause promoting short days (SD) than in reproduction promoting long days (LD), while Par Domain Protein 1 (Pdp1) mRNA level was higher in LD than in SD. The effect of photoperiod on gene expression was mediated by the neurosecretory cells of the pars intercerebralis (PI) and the juvenile hormone (JH) producing corpus allatum (CA). In LD-females, CA ablation resulted in SD-like levels of gene transcripts, while PI ablation had little effect. Conversely, in SD-females, CA ablation had only a little effect, while PI ablation resulted in LD-like levels of gene transcripts. Thus, the CA is responsible for LD-like characteristics of gene expression in reproducing females and the PI is responsible for SD-like characteristics of gene expression in diapausing females. A simultaneous ablation of both PI and CA revealed two roles of PI in SD-females: (1) inhibition of CA, and (2) weak CA-independent stimulation of cry2 mRNA. Overall, our results indicate that peripheral circadian gene expression in the gut reflects the physiological state of females (with respect to diapause or reproduction) rather than the external light-dark cycle.
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Affiliation(s)
- Adam Bajgar
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic
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Abstract
Summary
For millions of years, parasites have altered the behaviour of their hosts. Parasites can affect host behaviour by: (1) interfering with the host’s normal immune–neural communication, (2) secreting substances that directly alter neuronal activity via non-genomic mechanisms and (3) inducing genomic- and/or proteomic-based changes in the brain of the host. Changes in host behaviour are often restricted to particular behaviours, with many other behaviours remaining unaffected. Neuroscientists can produce this degree of selectivity by targeting specific brain areas. Parasites, however, do not selectively attack discrete brain areas. Parasites typically induce a variety of effects in several parts of the brain. Parasitic manipulation of host behaviour evolved within the context of the manipulation of other host physiological systems (especially the immune system) that was required for a parasite’s survival. This starting point, coupled with the fortuitous nature of evolutionary innovation and evolutionary pressures to minimize the costs of parasitic manipulation, likely contributed to the complex and indirect nature of the mechanisms involved in host behavioural control. Because parasites and neuroscientists use different tactics to control behaviour, studying the methods used by parasites can provide novel insights into how nervous systems generate and regulate behaviour. Studying how parasites influence host behaviour will also help us integrate genomic, proteomic and neurophysiological perspectives on behaviour.
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Affiliation(s)
- Shelley Anne Adamo
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
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Di Cara F, King-Jones K. How clocks and hormones act in concert to control the timing of insect development. Curr Top Dev Biol 2013; 105:1-36. [PMID: 23962837 DOI: 10.1016/b978-0-12-396968-2.00001-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
During the last century, insect model systems have provided fascinating insights into the endocrinology and developmental biology of all animals. During the insect life cycle, molts and metamorphosis delineate transitions from one developmental stage to the next. In most insects, pulses of the steroid hormone ecdysone drive these developmental transitions by activating signaling cascades in target tissues. In holometabolous insects, ecdysone triggers metamorphosis, the remarkable remodeling of an immature larva into a sexually mature adult. The input from another developmental hormone, juvenile hormone (JH), is required to repress metamorphosis by promoting juvenile fates until the larva has acquired sufficient nutrients to survive metamorphosis. Ecdysone and JH act together as key endocrine timers to precisely control the onset of developmental transitions such as the molts, pupation, or eclosion. In this review, we will focus on the role of the endocrine system and the circadian clock, both individually and together, in temporally regulating insect development. Since this is not a coherent field, we will review recent developments that serve as examples to illuminate this complex topic. First, we will consider studies conducted in Rhodnius that revealed how circadian pathways exert temporal control over the production and release of ecdysone. We will then take a look at molecular and genetic data that revealed the presence of two circadian clocks, located in the brain and the prothoracic gland, that regulate eclosion rhythms in Drosophila. In this context, we will also review recent developments that examined how the ecdysone hierarchy delays the differentiation of the crustacean cardioactive peptide (CCAP) neurons, an event that is critical for the timing of ecdysis and eclosion. Finally, we will discuss some recent findings that transformed our understanding of JH function.
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Affiliation(s)
- Francesca Di Cara
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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Bloch G, Hazan E, Rafaeli A. Circadian rhythms and endocrine functions in adult insects. JOURNAL OF INSECT PHYSIOLOGY 2013; 59:56-69. [PMID: 23103982 DOI: 10.1016/j.jinsphys.2012.10.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 10/09/2012] [Accepted: 10/11/2012] [Indexed: 06/01/2023]
Abstract
Many behavioral and physiological processes in adult insects are influenced by both the endocrine and circadian systems, suggesting that these two key physiological systems interact. We reviewed the literature and found that experiments explicitly testing these interactions in adult insects have only been conducted for a few species. There is a shortage of measurements of hormone titers throughout the day under constant conditions even for the juvenile hormones (JHs) and ecdysteroids, the best studied insect hormones. Nevertheless, the available measurements of hormone titers coupled with indirect evidence for circadian modulation of hormone biosynthesis rate, and the expression of genes encoding proteins involved in hormone biosynthesis, binding or degradation are consistent with the hypothesis that the circulating levels of many insect hormones are influenced by the circadian system. Whole genome microarray studies suggest that the modulation of farnesol oxidase levels is important for the circadian regulation of JH biosynthesis in honey bees, mosquitoes, and fruit flies. Several studies have begun to address the functional significance of circadian oscillations in endocrine signaling. The best understood system is the circadian regulation of Pheromone Biosynthesis Activating Neuropeptide (PBAN) titers which is important for the temporal organization of sexual behavior in female moths. The evidence that the circadian and endocrine systems interact has important implications for studies of insect physiology and behavior. Additional studies on diverse species and physiological processes are needed for identifying basic principles underlying the interactions between the circadian and endocrine systems in insects.
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Affiliation(s)
- Guy Bloch
- Department of Ecology, Evolution, and Behavior, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel.
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Vafopoulou X, Steel CGH. Insulin-like and testis ecdysiotropin neuropeptides are regulated by the circadian timing system in the brain during larval-adult development in the insect Rhodnius prolixus (Hemiptera). Gen Comp Endocrinol 2012; 179:277-88. [PMID: 22964530 DOI: 10.1016/j.ygcen.2012.08.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 08/14/2012] [Accepted: 08/20/2012] [Indexed: 11/19/2022]
Abstract
Insulin-like peptides (ILPs) regulate numerous functions in insects including growth, development, carbohydrate metabolism and female reproduction. This paper reports the immunohistochemical localization of ILPs in brain neurons of Rhodnius prolixus and their intimate associations with the brain circadian clock system. In larvae, three groups of neurons in the protocerebrum are ILP-positive, and testis ecdysiotropin (TE) is co-localized in two of them. During adult development, the number of ILP groups increased to four. A blood meal initiates transport and release of ILPs, indicating that release is nutrient dependent. Both production and axonal transport of ILPs continue during adult development with clear cytological evidence of a daily rhythm that closely correlates with the daily rhythm of ILPs release from brains in vitro. The same phenomena were observed with TE previously. Double labeling for ILPs and pigment dispersing factor (PDF) (contained in the brain lateral clock cells, LNs) revealed intimate associations between axons of the ILP/TE cells and PDF-positive axons in both central brain and retrocerebral complex, revealing potential neuronal pathways for circadian regulation of ILPs and TE. Similar close associations were found previously between LN axons and axons of the brain neurons producing the neuropeptide prothoracicotropic hormone. Thus, the brain clock system controls rhythmicity in multiple brain neurohormones. It is suggested that rhythms in circulating ILPs and TE act in concert with known rhythms of circulating ecdysteroids in both larvae and adults to orchestrate the timing of cellular responses in diverse tissues of the animal, thereby generating internal temporal order within it.
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Relationship between the expression of Rab family GTPases and neuropeptide hormones in the brain of Bombyx mori. Histochem Cell Biol 2012; 139:299-308. [PMID: 22922733 DOI: 10.1007/s00418-012-1021-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/07/2012] [Indexed: 01/25/2023]
Abstract
Rab proteins are small GTPases that play essential roles in vesicle transport. In this study, we examined the expression of Rab proteins and neuropeptide hormones in the brain of the silkworm, Bombyx mori. We produced antibodies against B. mori Rab1 and Rab14 in rabbits. Immunoblotting of samples of brain tissue from B. mori revealed a single band for each antibody. Rab1 and Rab14 immunohistochemical labeling in the brain of B. mori was restricted to neurons of the pars intercerebralis and dorsolateral protocerebrum. Rab1, Rab7 and Rab14 co-localized with bombyxin. Rab1 and Rab7 co-localized with eclosion hormone. Rab1 co-localized with prothoracicotropic hormone. These results suggest that Rab1, Rab7 and Rab14 may be involved in neuropeptide transport in the brain of B. mori. This is the first report on the specificity of Rab proteins for the secretion of different neuropeptides in insects.
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Neuronal influence on peripheral circadian oscillators in pupal Drosophila prothoracic glands. Nat Commun 2012; 3:909. [PMID: 22713751 PMCID: PMC3621432 DOI: 10.1038/ncomms1922] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 05/22/2012] [Indexed: 11/08/2022] Open
Abstract
Rhythmic expression of period (per) and timeless (tim) genes in central circadian pacemaker neurons and prothoracic gland cells, part of the peripheral circadian oscillators in flies, may synergistically control eclosion rhythms, but their oscillatory profiles remain unclear. Here we show differences and interactions between peripheral and central oscillators using per-luciferase and cytosolic Ca2+ reporter (yellow cameleon) imaging in organotypic prothoracic gland cultures with or without the associated central nervous system. Isolated prothoracic gland cells exhibit light-insensitive synchronous per-transcriptional rhythms. In prothoracic gland cells associated with the central nervous system, however, per transcription is markedly amplified following 12-h light exposure, resulting in the manifestation of day–night rhythms in nuclear PER immunostaining levels and spontaneous Ca2+ spiking. Unlike PER expression, nuclear TIM expression is associated with day–night cycles that are independent of the central nervous system. These results demonstrate that photoreception and synaptic signal transduction in/from the central nervous system coordinate molecular 'gears' in endocrine oscillators to generate physiological rhythms. In the fruit fly Drosophila, changes in expression of circadian clock genes are believed to control eclosion. Morioka and colleagues show that transcriptional oscillations of the clock gene, period, in prothoracic gland cells are amplified by photic inputs from the central nervous system.
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Vafopoulou X, Steel CGH. Cytoplasmic travels of the ecdysteroid receptor in target cells: pathways for both genomic and non-genomic actions. Front Endocrinol (Lausanne) 2012; 3:43. [PMID: 22654867 PMCID: PMC3356023 DOI: 10.3389/fendo.2012.00043] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Accepted: 03/06/2012] [Indexed: 12/20/2022] Open
Abstract
Signal transduction of the insect steroid hormones, ecdysteroids, is mediated by the ecdysteroid receptor, EcR. In various cells of the insect Rhodnius prolixus, EcR is present in both the nucleus and the cytoplasm, where it undergoes daily cycling in abundance and cellular location at particular developmental times of the last larval instar that are specific to different cell types. EcR favors a cytoplasmic location in the day and a nuclear location in the night. This study is the first to examine the potential mechanisms of intracellular transport of EcR and reveals close similarities with some of its mammalian counterparts. In double and triple labels using several antibodies, immunohistochemistry, and confocal laser scanning microscopy, we observed co-localization of EcR with the microtubules (MTs). Treatments with either the MT-stabilizing agent taxol or with colchicine, which depolymerizes MTs, resulted in considerable reduction in nuclear EcR with a concomitant increase in cytoplasmic EcR suggesting that MT disruption inhibits receptor accumulation in the nucleus. EcR also co-localizes with the chaperone Hsp90, the immunophilin FKBP52, and the light chain 1 of the motor protein dynein. All these factors also co-localize with MTs. We propose that in Rhodnius, EcR exerts its genomic effects by forming a complex with Hsp90 and FKBP52, which uses dynein on MTs as a mechanism for daily nucleocytoplasmic shuttling. The complex is transported intact to the nucleus and dissociates within it. We propose that EcR utilizes the cytoskeletal tracks for movement in a manner closely similar to that used by the glucocorticoid receptor. We also observed co-localization of EcR with mitochondria which suggests that EcR, like its mammalian counterparts, may be involved in the coordination of non-genomic responses of ecdysteroids in mitochondria.
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Peripheral circadian rhythms and their regulatory mechanism in insects and some other arthropods: a review. J Comp Physiol B 2012; 182:729-40. [PMID: 22327195 DOI: 10.1007/s00360-012-0651-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 01/18/2012] [Accepted: 01/26/2012] [Indexed: 01/15/2023]
Abstract
Many physiological functions of insects show a rhythmic change to adapt to daily environmental cycles. These rhythms are controlled by a multi-clock system. A principal clock located in the brain usually organizes the overall behavioral rhythms, so that it is called the "central clock". However, the rhythms observed in a variety of peripheral tissues are often driven by clocks that reside in those tissues. Such autonomous rhythms can be found in sensory organs, digestive and reproductive systems. Using Drosophila melanogaster as a model organism, researchers have revealed that the peripheral clocks are self-sustained oscillators with a molecular machinery slightly different from that of the central clock. However, individual clocks normally run in harmony with each other to keep a coordinated temporal structure within an animal. How can this be achieved? What is the molecular mechanism underlying the oscillation? Also how are the peripheral clocks entrained by light-dark cycles? There are still many questions remaining in this research field. In the last several years, molecular techniques have become available in non-model insects so that the molecular oscillatory mechanisms are comparatively investigated among different insects, which give us more hints to understand the essential regulatory mechanism of the multi-oscillatory system across insects and other arthropods. Here we review current knowledge on arthropod's peripheral clocks and discuss their physiological roles and molecular mechanisms.
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Vafopoulou X, Steel CG. Metamorphosis of a clock: Remodeling of the circadian timing system in the brain of Rhodnius prolixus (Hemiptera) during larval-adult development. J Comp Neurol 2012; 520:1146-64. [DOI: 10.1002/cne.22743] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Rhythmic release of prothoracicotropic hormone from the brain of an adult insect during egg development. Comp Biochem Physiol A Mol Integr Physiol 2012; 161:193-200. [DOI: 10.1016/j.cbpa.2011.10.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 10/25/2011] [Accepted: 10/26/2011] [Indexed: 11/20/2022]
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Itoh TQ, Tanimura T, Matsumoto A. Membrane-bound transporter controls the circadian transcription of clock genes in Drosophila. Genes Cells 2011; 16:1159-67. [PMID: 22077638 DOI: 10.1111/j.1365-2443.2011.01559.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Little is known about molecular mechanisms that control the Drosophila circadian clock beyond the transcriptional-translational feedback regulation of clock genes as an intracellular process. In this study, Early gene at 23 (E23) was identified as a novel clock gene that encodes the membrane-bound ABC transporter that is induced by the molting hormone ecdysone. E23 expresses in pacemaker neurons in fly head, and its knockdown flies lengthened circadian period with an increased expression of the clock gene vrille. E23 and vrille responded to both ecdysone and clock signals, whereas E23 protein specifically suppressed the ecdysone response and is necessary for rhythmicity. Thus, E23 forms its own feedback loop in the ecdysone response to control circadian oscillation through ecdysone-mediated vrille expression. The ecdysone signaling pathway with E23 is essential not only in developmental stage but also for the circadian behavior in adult fly.
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Affiliation(s)
- Taichi Q Itoh
- Graduate School of Systems Life Sciences, Kyushu University, Hakozaki, Fukuoka, Japan
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Zhang Q, Denlinger DL. Molecular structure of the prothoracicotropic hormone gene in the northern house mosquito, Culex pipiens, and its expression analysis in association with diapause and blood feeding. INSECT MOLECULAR BIOLOGY 2011; 20:201-13. [PMID: 21118326 PMCID: PMC3059851 DOI: 10.1111/j.1365-2583.2010.01058.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We cloned the gene that encodes prothoracicotropic hormone (PTTH) in the northern house mosquito, Culex pipiens, and investigated its expression profile in short-day (diapause-destined) and long-day (nondiapause-destined) individuals from the fourth-instar larval stage to 2 months of adulthood, as well as after a blood meal. The deduced C. pipiens PTTH (Cupip-PTTH) amino acid sequence contains seven cysteines with a specific spacing pattern. Sequence alignment suggests that Cupip-PTTH is 23% identical to Drosophila melanogaster PTTH, but is ≥59% identical to the PTTHs of other mosquitoes. Cupip-PTTH has structural characteristics similar to those of Bombyx mori PTTH and some vertebrate nerve growth factors with cysteine-knot motifs. PTTH transcripts exhibit a daily cycling profile during the final (fourth) larval instar, with peak abundance occurring late in the scotophase. The fourth-larval instar stage is one day longer in short-day larvae than in long-day larvae, resulting in larger larvae and adults. This additional day of larval development is associated with one extra PTTH cycle. No cycling was observed in pupae, but PTTH transcripts were slightly higher in short-day pupae than in long-day pupae throughout much of the pupal stage. PTTH expression persisted at a nearly constant level in diapausing adult females for the first month but then dropped by ∼50%, while expression decreased at the beginning of adulthood in nondiapausing females and then remained at a low level as long as the females were denied a blood meal. However, when nondiapausing females were offered a blood meal, PTTH transcripts rose approximately 7 fold in 2 h and remained elevated for 24 h. A few diapausing females (∼10%) will take a blood meal when placed in close proximity to a host, but much of the blood is ejected and such meals do not result in mature eggs. Yet, elevated PTTH mRNA expression was also observed in diapausing females that were force fed. Our results thus point to several distinctions in PTTH expression between short-day and long-day mosquitoes, but both types of females responded to a blood meal by elevating levels of PTTH mRNA.
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Affiliation(s)
- Qirui Zhang
- Department of Entomology, Ohio State University, 318 West 12th Avenue, Columbus, OH 43210, USA
| | - David L. Denlinger
- Department of Entomology, Ohio State University, 318 West 12th Avenue, Columbus, OH 43210, USA
- Corresponding author. Tel.: +1 614 2926425; Fax: +1 614 2922180. (D.L. Denlinger)
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Uno T, Hata K, Hiragaki S, Isoyama Y, Trang LTD, Uno Y, Kanamaru K, Yamagata H, Nakamura M, Takagi M, Takeda M. Small GTPases of the Rab family in the brain of Bombyx mori. Histochem Cell Biol 2010; 134:615-22. [DOI: 10.1007/s00418-010-0755-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2010] [Indexed: 11/24/2022]
Affiliation(s)
- Tomohide Uno
- Department of Biofunctional Chemistry, Faculty of Agriculture, Kobe University, Nada-ku, Kobe, Hyogo, Japan.
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Giebultowicz J. CIRCADIAN WINDOW OF OPPORTUNITY: WHAT HAVE WE LEARNED FROM INSECTS? J Exp Biol 2010; 213:185-6. [DOI: 10.1242/jeb.034199] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Santini MS, Ronderos JR. Daily variation of an allatotropin-like peptide in the Chagas disease vectorTriatoma infestans(klug). BIOL RHYTHM RES 2009. [DOI: 10.1080/09291010802214583] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Fónagy A. Insect timing (rhythms) from the point of view of neuroendocrine effector mechanisms. ACTA ACUST UNITED AC 2009. [DOI: 10.1556/aphyt.44.2009.1.7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Zera AJ, Zhao Z. Morph-associated JH titer diel rhythm in Gryllus firmus: Experimental verification of its circadian basis and cycle characterization in artificially selected lines raised in the field. JOURNAL OF INSECT PHYSIOLOGY 2009; 55:450-458. [PMID: 19100744 DOI: 10.1016/j.jinsphys.2008.11.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 11/17/2008] [Accepted: 11/21/2008] [Indexed: 05/27/2023]
Abstract
Previous studies demonstrated a high-amplitude, diel cycle for the hemolymph JH titer in the wing-polymorphic cricket, Gryllus firmus. The JH titer rose and fell in the flight-capable morph (long-winged, LW(f)) above and below the relatively temporally invariant JH titer in the flightless (short-winged, SW) morph. The morph-specific JH titer cycle appeared to be primarily driven by a morph-specific diel cycle in the rate of JH biosynthesis. In the present study, cycles of the JH titer and rate of JH biosynthesis in the LW(f) morph persisted in the laboratory under constant darkness with an approximate 24h periodicity. The JH titer cycle also shifted in concert with a shift in the onset of the scotophase, was temperature compensated in constant darkness, and became arrhythmic under constant light. These results provide strong support for the circadian basis of the morph-specific diel rhythm of the JH titer and JH biosynthetic rate. Persistence of the JH titer cycle under constant darkness in multiple LW-selected and SW-selected stocks also provides support for the genetic basis of the morph-associated circadian rhythm. The morph-specific JH titer cycle was observed in these stocks raised in the field, in both males and females, in each of 3 years studied. The onset of the cycle in the LW(f) morph, a few hours before sunset, correlated well with the onset of the cycle, a few hours before lights-off, in the laboratory. The morph-specific JH titer cycle is a general feature of G. firmus, under a variety of environmental conditions, and is not an artifact of specific laboratory conditions or specific genetic stocks. It is a powerful experimental model to investigate the mechanisms underlying endocrine circadian rhythms, their evolution, and their impact on life history evolution.
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Affiliation(s)
- Anthony J Zera
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588-0118, United States.
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Putative regulatory mechanism of prothoracicotropic hormone (PTTH) secretion in the American cockroach, Periplaneta americana as inferred from co-localization of Rab8, PTTH, and protein kinase C in neurosecretory cells. Cell Tissue Res 2009; 335:607-15. [PMID: 19156439 DOI: 10.1007/s00441-008-0747-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2008] [Accepted: 12/18/2008] [Indexed: 10/21/2022]
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Sandrelli F, Costa R, Kyriacou CP, Rosato E. Comparative analysis of circadian clock genes in insects. INSECT MOLECULAR BIOLOGY 2008; 17:447-463. [PMID: 18828836 DOI: 10.1111/j.1365-2583.2008.00832.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
After a slow start, the comparative analysis of clock genes in insects has developed into a mature area of study in recent years. Brain transplant or surgical interventions in larger insects defined much of the early work in this area, before the cloning of clock genes became possible. We discuss the evolution of clock genes, their key sequence differences, and their likely modes of regulation in several different insect orders. We also present their expression patterns in the brain, focusing particularly on Diptera, Lepidoptera, and Orthoptera, the most common non-genetic model insects studied. We also highlight the adaptive involvement of clock molecules in other complex phenotypes which require biological timing, such as social behaviour, diapause and migration.
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Affiliation(s)
- F Sandrelli
- Department of Biology, University of Padova, Padova 35131, Italy
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Zera AJ, Zhao Z, Kaliseck K. Hormones in the Field: Evolutionary Endocrinology of Juvenile Hormone and Ecdysteroids in Field Populations of the Wing‐Dimorphic CricketGryllus firmus. Physiol Biochem Zool 2007; 80:592-606. [PMID: 17909996 DOI: 10.1086/521803] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/25/2007] [Indexed: 11/03/2022]
Abstract
Virtually no published information exists on insect endocrine traits in natural populations, which limits our understanding of endocrine microevolution. We characterized the hemolymph titers of juvenile hormone (JH) and ecdysteroids (ECDs), two key insect hormones, in field-collected short-winged, flightless (SW) and long-winged, flight-capable (LW(f)) morphs of the cricket Gryllus firmus. The JH titer exhibited a dramatic circadian rhythm in the LW(f) morph but was temporally constant in the flightless SW morph. This pattern was consistent in each of three years; in young, middle-aged, and older G. firmus; and in three other cricket species. The ECD titer was considerably higher in SW than in LW(f) females but did not exhibit temporal variation in any morph and did not differ between male morphs. JH and ECD may control different aspects of the morph-specific trade-off between nocturnal dispersal and reproduction. Results confirm and extend laboratory studies on young female G. firmus; most, but not all, important aspects of morph-specific differences in JH and ECD titers can be extrapolated from field to laboratory environments and vice versa. Hormone titers in Gryllus are more complex than those proposed in evolutionary endocrine models. Directly measuring hormone titer variation remains a fundamentally important task of insect evolutionary endocrinology.
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Affiliation(s)
- Anthony J Zera
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska 68588, USA.
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46
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Huang Y, Genova G, Roberts M, Jackson FR. The LARK RNA-binding protein selectively regulates the circadian eclosion rhythm by controlling E74 protein expression. PLoS One 2007; 2:e1107. [PMID: 17971870 PMCID: PMC2040218 DOI: 10.1371/journal.pone.0001107] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Accepted: 10/05/2007] [Indexed: 11/19/2022] Open
Abstract
Despite substantial progress in defining central components of the circadian pacemaker, the output pathways coupling the clock to rhythmic physiological events remain elusive. We previously showed that LARK is a Drosophila RNA-binding protein which functions downstream of the clock to mediate behavioral outputs. To better understand the roles of LARK in the circadian system, we sought to identify RNA molecules associated with it, in vivo, using a three-part strategy to (1) capture RNA ligands by immunoprecipitation, (2) visualize the captured RNAs using whole-genome microarrays, and (3) identify functionally relevant targets through genetic screens. We found that LARK is associated with a large number of RNAs, in vivo, consistent with its broad expression pattern. Overexpression of LARK increases protein abundance for certain targets without affecting RNA level, suggesting a translational regulatory role for the RNA-binding protein. Phenotypic screens of target-gene mutants have identified several with rhythm-specific circadian defects, indicative of effects on clock output pathways. In particular, a hypomorphic mutation in the E74 gene, E74(BG01805), was found to confer an early-eclosion phenotype reminiscent of that displayed by a mutant with decreased LARK gene dosage. Molecular analyses demonstrate that E74A protein shows diurnal changes in abundance, similar to LARK. In addition, the E74(BG01805) allele enhances the lethal phenotype associated with a lark null mutation, whereas overexpression of LARK suppresses the early eclosion phenotype of E74(BG01805), consistent with the idea that E74 is a target, in vivo. Our results suggest a model wherein LARK mediates the transfer of temporal information from the molecular oscillator to different output pathways by interacting with distinct RNA targets.
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Affiliation(s)
- Yanmei Huang
- Department of Neuroscience, Center for Neuroscience Research, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Ginka Genova
- Department of Neuroscience, Center for Neuroscience Research, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Mary Roberts
- Department of Neuroscience, Center for Neuroscience Research, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - F. Rob Jackson
- Department of Neuroscience, Center for Neuroscience Research, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- * To whom correspondence should be addressed. E-mail:
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Schuckel J, Siwicki KK, Stengl M. Putative circadian pacemaker cells in the antenna of the hawkmoth Manduca sexta. Cell Tissue Res 2007; 330:271-8. [PMID: 17786482 DOI: 10.1007/s00441-007-0471-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Accepted: 07/08/2007] [Indexed: 11/25/2022]
Abstract
Antennal sensory neurons in the fruit fly Drosophila melanogaster express circadian rhythms in the clock gene PERIOD (PER) and appear to be sufficient and necessary for circadian rhythms in olfactory responses. Given recent evidence for daily rhythms of pheromone responses in the antenna of the hawkmoth Manduca sexta, we examined whether a peripheral PER-based circadian clock might be present in this species. Several different cell types in the moth antenna were recognized by monoclonal antibodies against Manduca sexta PER. In addition to PER-like staining of pheromone-sensitive olfactory receptor neurons and supporting cells, immunoreactivity was detected in beaded branches contacting the pheromone-sensitive sensilla. The nuclei of apparently all sensory receptor neurons, of sensilla supporting cells, of epithelial cells, and of antennal nerve glial cells were PER-immunoreactive. Expression of per mRNA in antennae was confirmed by the polymerase chain reaction, which showed stronger expression at Zeitgeber-time 15 compared with Zeitgeber-time 3. This evidence for the expression of per gene products suggests that the antenna of the hawkmoth contains endogenous circadian clocks.
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Affiliation(s)
- Julia Schuckel
- Biology, Animal Physiology, Philipps University of Marburg, Karl von Frisch Strasse, 35043, Marburg, Germany
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48
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Vafopoulou X, Steel CGH, Terry KL. Neuroanatomical relations of prothoracicotropic hormone neurons with the circadian timekeeping system in the brain of larval and adultRhodnius prolixus (Hemiptera). J Comp Neurol 2007; 503:511-24. [PMID: 17534946 DOI: 10.1002/cne.21393] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This paper reports the localization in the Rhodnius prolixus brain of neurons producing the key neuropeptide that regulates insect development, prothoracicotropic hormone (PTTH) and describes intimate associations of the PTTH neurons with the brain circadian timekeeping system. Immunohistochemistry and confocal laser scanning microscopy revealed that the PTTH-positive neurons in larvae are located in a single group in the lateral protocerebrum. Their number increases from two in the last larval instar to five during larval-adult development. In adults, there are two distinct groups of these neurons composed of two cells each. A daily rhythm in content of PTTH-positive material occurs in both the somata and the axons in both larval and adult stages. These rhythms correlate with previous evidence of a circadian rhythm of PTTH release from brains in vitro. The key circadian clock cells of Rhodnius are eight neurons, which co-express pigment-dispersing factor (PDF) and the canonical clock proteins PER and TIM; PDF fills the axons. Equivalent cells control behavioral rhythms in other insects. Double labeling revealed intimate associations between axons of larval PTTH neurons and clock neurons, indicating a neuronal pathway from the brain timekeeping system for circadian control of PTTH release. Additional PDF neurons appear in the adult, associated with the second group of PTTH neurons. These findings provide the first direct evidence that neurons of the insect brain timekeeping system control hormone rhythms. The range of functions regulated by this timekeeping system is quite similar to those of the vertebrate suprachiasmatic nucleus, for which the insect system is a valuable model.
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Affiliation(s)
- Xanthe Vafopoulou
- Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada.
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49
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Trudeau VL. Comparative neuroendocrinology: Integration of hormonal and environmental signals in vertebrates and invertebrates. Comp Biochem Physiol A Mol Integr Physiol 2006; 144:243-6. [PMID: 16697672 DOI: 10.1016/j.cbpa.2006.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Accepted: 03/09/2006] [Indexed: 10/24/2022]
Affiliation(s)
- Vance L Trudeau
- Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Canada
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