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Angela B. Lange - One of the best experts on this subject based on the ideXlab platform.
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Crustacean Cardioactive Peptide in the chagas disease vector rhodnius prolixus presence distribution and physiological effects
General and Comparative Endocrinology, 2011Co-Authors: Do Hee Lee, Angela B. LangeAbstract:Abstract Crustacean Cardioactive Peptide (CCAP), a cyclic nonaPeptide (PFCNAFTGCamide), has multifunctional roles in insects including stimulating visceral and cardiac muscle contraction, and regulating ecdysis. Previously, we have sequenced the cDNA for CCAP from Rhodnius prolixus central nervous system (CNS) and shown expression of the CCAP transcript in neurons of the CNS. In the present study, we have biochemically identified and sequenced CCAP from 5th instar R. prolixus CNS using matrix-assisted laser desorption ionization-time of flight-tandem mass spectrometry, and mapped CCAP-like immunoreactivity in the CNS and peripheral tissues of 5th instar R. prolixus . Physiologically, the hindgut of R. prolixus was found to be sensitive to CCAP, showing dose-dependent increases in contractions with threshold at 5 × 10 −9 M and maximum response at 10 −7 M CCAP. Also, CCAP was found to increase the frequency of the heartbeat in a reversible, dose-dependent manner, with threshold close to 10 −11 M and maximum response at 10 −10 M CCAP.
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effects of Crustacean Cardioactive Peptide on the hearts of two orthopteran insects and the demonstration of a frank starling like effect
General and Comparative Endocrinology, 2011Co-Authors: Sara R Da Silva, Rosa Da Silva, Angela B. LangeAbstract:Abstract Like vertebrate cardiovascular systems, the dorsal vessel of the Orthopteran insects Baculum extradentatum and Locusta migratoria is under myogenic as well as neural control, through the action of neurotransmitters, neuromodulators and neurohormones. It was previously shown that the excitatory neuroPeptide, Crustacean Cardioactive Peptide (CCAP), triggers an increase in heart rate in B. extradentatum , and CCAP-like immunoreactivity is present in the innervation to the heart in many insects. In the present study, CCAP resulted in a dose-dependent increase in heart rate and hemolymph flow velocity, or cardiac output, in B. extradentatum . In contrast, CCAP led to a significant increase in stroke volume and cardiac output in L. migratoria without modifying heart rate or aortic contraction frequency. Hemolymph flow through the excurrent ostia of L. migratoria , small openings or valves on the posterior aorta and anterior heart, was inhibited with increasing concentrations of CCAP, with complete inhibition seen at 10 −7 M CCAP. In the locust, CCAP increases the volume of hemolymph in the dorsal vessel by the synchronous closing of the excurrent ostia, resulting in more forceful heart contractions and increased stroke volume and cardiac output, without modifying heart rate through a physiological mechanism analogous to the Frank–Starling mechanism in vertebrates. Therefore, Crustacean Cardioactive Peptide alters the contractile properties of cardiac tissue in both B. extradentatum and L. migratoria , allowing for an increase in blood flow and circulation.
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isolation cloning and expression of the Crustacean Cardioactive Peptide gene in the chagas disease vector rhodnius prolixus
Peptides, 2011Co-Authors: J P Paluzzi, Ian Orchard, Angela B. LangeAbstract:Abstract The blood-gorging bug, Rhodnius prolixus , is a major vector of Chagas’ disease in Central and South America. We have cloned and characterized the Crustacean Cardioactive Peptide (CCAP) gene in R. prolixus . The RhoprCCAP gene contains five exons and four introns, and encodes a 129 amino acid preproPeptide, which following post-translation processing, produces CCAP. The predicted RhoprCCAP amino acid sequence is identical to CCAP of Crustaceans and other insects, i.e. it is highly conserved. RhoprCCAP mRNA is observed in the central nervous system (CNS) using reverse transcriptase (RT) PCR, but not in the gut and salivary glands. In situ hybridization reveals that the expression of CCAP mRNA is localized to a small number of dorsally situated bilaterally paired neurons within the CNS.
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Effects of Crustacean Cardioactive Peptide on the hearts of two Orthopteran insects, and the demonstration of a Frank–Starling-like effect
General and Comparative Endocrinology, 2011Co-Authors: Sara R Da Silva, Rosa Da Silva, Angela B. LangeAbstract:Abstract Like vertebrate cardiovascular systems, the dorsal vessel of the Orthopteran insects Baculum extradentatum and Locusta migratoria is under myogenic as well as neural control, through the action of neurotransmitters, neuromodulators and neurohormones. It was previously shown that the excitatory neuroPeptide, Crustacean Cardioactive Peptide (CCAP), triggers an increase in heart rate in B. extradentatum , and CCAP-like immunoreactivity is present in the innervation to the heart in many insects. In the present study, CCAP resulted in a dose-dependent increase in heart rate and hemolymph flow velocity, or cardiac output, in B. extradentatum . In contrast, CCAP led to a significant increase in stroke volume and cardiac output in L. migratoria without modifying heart rate or aortic contraction frequency. Hemolymph flow through the excurrent ostia of L. migratoria , small openings or valves on the posterior aorta and anterior heart, was inhibited with increasing concentrations of CCAP, with complete inhibition seen at 10 −7 M CCAP. In the locust, CCAP increases the volume of hemolymph in the dorsal vessel by the synchronous closing of the excurrent ostia, resulting in more forceful heart contractions and increased stroke volume and cardiac output, without modifying heart rate through a physiological mechanism analogous to the Frank–Starling mechanism in vertebrates. Therefore, Crustacean Cardioactive Peptide alters the contractile properties of cardiac tissue in both B. extradentatum and L. migratoria , allowing for an increase in blood flow and circulation.
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The association of Crustacean Cardioactive Peptide with the spermatheca of the African migratory locust, Locusta migratoria
Journal of insect physiology, 2006Co-Authors: Rosa Da Silva, Angela B. LangeAbstract:Abstract Crustacean Cardioactive Peptide (CCAP)-like immunoreactivity was identified in neurons of the VIIIth abdominal ganglion and in axons in the nerves that project to the spermatheca of 3–4 week old adult female locusts. In addition, lightly stained CCAP-like immunoreactive processes were localized over the spermathecae. The amount of CCAP in the spermathecal tissue was quantified using an enzyme-linked immunosorbent assay (ELISA) performed on extracts of the whole spermatheca, and on its constituent parts, namely the sperm sac, coiled duct and straight duct. The spermatheca contains 920±273 fmol (mean±SE) of CCAP equivalents, with the majority localized in the coiled duct. There are age-related differences in the amount of CCAP present in the spermathecae with less content in spermathecae from 1 to 5 day old and greater content in spermathecae from 3 to 4 week old adults. There was also no difference in CCAP content of spermathecae in mated and virgin 3 to 4 week old adults. Reversed phase-high performance liquid chromatography (RP-HPLC) followed by ELISA further confirmed the presence of CCAP-like material in extracts of locust spermathecae. Physiological assays demonstrated that CCAP increased the basal tonus and frequency of spontaneous contractions of the spermatheca, with thresholds between 10−10 and 10−9 M and maxima at 10−7 M CCAP. CCAP also increases the amplitude of neurally evoked contractions with a threshold less than 10−11 M and a maximum of 10−7 M CCAP. The present study suggests that CCAP acts as a neuromodulator/neurotransmitter at the spermathecal visceral tissue of female Locusta migratoria.
Heinrich Dircksen - One of the best experts on this subject based on the ideXlab platform.
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Identification and developmental expression of mRNAs encoding Crustacean Cardioactive Peptide (CCAP) in decapod Crustaceans
Journal of Experimental Biology, 2006Co-Authors: J S Chung, Heinrich Dircksen, David C. Wilcockson, N. Zmora, Y. Zohar, Simon G. WebsterAbstract:Full-length cDNAs encoding Crustacean Cardioactive Peptide (CCAP) were isolated from several decapod (brachyuran and astacuran) Crustaceans: the blue crab Callinectes sapidus, green shore crab Carcinus maenas, European lobster Homarus gamarus and calico crayfish Orconectes immunis. The cDNAs encode open reading frames of 143 (brachyurans) and 139-140 (astacurans) amino acids. Apart from the predicted signal Peptides (30-32 amino acids), the conceptually translated precursor codes for a single copy of CCAP and four other Peptides that are extremely similar in terms of amino acid sequence within these species, but which clearly show divergence into brachyuran and astacuran groups. Expression patterns of CCAP mRNA and Peptide were determined during embryonic development in Carcinus using quantitative RT-PCR and immunohistochemistry with whole-mount confocal microscopy, and showed that significant mRNA expression (at 50% embryonic development) preceded detectable levels of CCAP in the developing central nervous system (CNS; at 70% development). Subsequent CCAP gene expression dramatically increased during the late stages of embryogenesis (80-100%), coincident with developing immunopositive structures. In adult crabs, CCAP gene expression was detected exclusively in the eyestalk, brain and in particular the thoracic ganglia, in accord with the predominance of CCAP-containing cells in this tissue. Measurement of expression patterns of CCAP mRNA in Carcinus and Callinectes thoracic ganglia throughout the moult cycle revealed only modest changes, indicating that previously observed increases in CCAP Peptide levels during premoult were not transcriptionally coupled. Severe hypoxic conditions resulted in rapid downregulation of CCAP transcription in the eyestalk, but not the thoracic ganglia in Callinectes, and thermal challenge did not change CCAP mRNA levels. These results offer the first tantalising glimpses of involvement of CCAP in environmental adaptation to extreme, yet biologically relevant stressors, and perhaps suggest that the CCAP-containing neurones in the eyestalk might be involved in adaptation to environmental stressors.
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Conserved Crustacean Cardioactive Peptide (CCAP) neuronal networks and functions in arthropod evolution.
1998Co-Authors: Heinrich Dircksen, G. M. Coast, Simon G. WebsterAbstract:Conserved Crustacean Cardioactive Peptide neural networks and functions in arthropod evolution
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Putative neurohemal areas in the peripheral nervous system of an insect, Gryllus bimaculatus, revealed by immunocytochemistry
Cell and Tissue Research, 1995Co-Authors: Johannes Helle, Heinrich Dircksen, Manfred Eckert, Dick R. Nässel, Ulrike Spörhase-eichmann, Friedrich-wilhelm SchürmannAbstract:The morphology and position of putative neurohemal areas in the peripheral nervous system (ventral nerve cord and retrocerebral complex) of the cricket Gryllus bimaculatus are described. By using antisera to the amines dopamine, histamine, octopamine, and serotonin, and the neuroPeptides Crustacean Cardioactive Peptide, FMRFamide, leucokinin 1, and proctolin, an extensive system of varicose fibers has been detected throughout the nerves of all neuromeres, except for nerve 2 of the prothoracic ganglion. Immunoreactive varicose fibers occur mainly in a superficial position at the neurilemma, indicating neurosecretory storage and release of neuroactive compounds. The varicose fibers are projections from central or peripheral neurons that may extend over more than one segment. The peripheral fiber varicosities show segment-specific arrangements for each of the substances investigated. Immunoreactivity to histamine and octopamine is mainly found in the nerves of abdominal segments, whereas serotonin immunoreactivity is concentrated in subesophageal and terminal ganglion nerves. Immunoreactivity to FMRFamide and Crustacean Cardioactive Peptide is widespread throughout all segments. Structures immunoreactive to leucokinin 1 are present in abdominal nerves, and proctolin immunostaining is found in the terminal ganglion and thoracic nerves. Codistribution of peripheral varicose fiber plexuses is regularly seen for amines and Peptides, whereas the colocalization of substances in neurons has not been detected for any of the neuroactive compounds investigated. The varicose fiber system is regarded as complementary to the classical neurohemal organs.
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Crustacean Cardioactive Peptide immunoreactive neurons innervating brain neuropils retrocerebral complex and stomatogastric nervous system of the locust locusta migratoria
Cell and Tissue Research, 1995Co-Authors: Heinrich Dircksen, Uwe HombergAbstract:The distribution and morphology of Crustacean Cardioactive Peptide-immunoreactive neurons in the brain of the locust Locusta migratoria has been determined. Of more than 500 immunoreactive neurons in total, about 380 are interneurons in the optic lobes. These neurons invade several layers of the medulla and distal parts of the lobula. In addition, a small group of neurons projects into the accessory medulla, the lamina, and to several areas in the median protocerebrum. In the midbrain, 12 groups or individual neurons have been reconstructed. Four groups innervate areas of the superior lateral and ventral lateral protocerebrum and the lateral horn. Two cell groups have bilateral arborizations anterior and posterior to the central body or in the superior median protocerebrum. Ramifications in subunits of the central body and in the lateral and the median accessory lobes arise from four additional cell groups. Two local interneurons innervate the antennal lobe. A tritocerebral cell projects contralaterally into the frontal ganglion and appears to give rise to fibers in the recurrent nerve, and in the hypocerebral and ingluvial ganglia. Varicose fibers in the nervi corporis cardiaci III and the corpora cardiaca, and terminals on pharyngeal dilator muscles arise from two subesophageal neurons. Some of the locust neurons closely resemble immunopositive neurons in a beetle and a moth. Our results suggest that the Peptide may be (1) a modulatory substance produced by many brain interneurons, and (2) a neurohormone released from subesophageal neurosecretory cells.
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Common general morphological pattern of Peptidergic neurons in the arachnid brain: Crustacean Cardioactive Peptide-immunoreactive neurons in the protocerebrum of seven arachnid species
Cell and Tissue Research, 1995Co-Authors: Olaf Breidbach, Heinrich Dircksen, Rainer WegerhoffAbstract:A polyclonal antiserum raised against Crustacean Cardioactive Peptide labels 14 clusters of immunoreactive neurons in the protocerebrum of the spiders Tegenaria atrica and Nephila clavipes , and the harvestman (opilionid) Rilaena triangularis . In all species, these clusters possess the same number of neurons, and share similar structural and topological characteristics. Two sets of bilateral symmetrical neurons associated with the optic lobes and the arachnid “central body” were analysed in detail, comparing the harvestman R. triangularis and the spiders Brachypelma albopilosa (Theraphosidae), Cupiennius salei (Lycosidae), Tegenaria atrica (Agelenidae), Meta segmentata (Metidae) and Nephila clavipes (Araneidae). Sixteen neurons have been identified that display markedly similar axonal pathways and arborization patterns in all species. These neurons are considered homologues in the opilionid and the araneid brains. We presume that these putative phylogenetically persisting neurons represent part of the general morphological pattern of the arachmid brain.
Olaf Breidbach - One of the best experts on this subject based on the ideXlab platform.
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Embryonic and postembryonic development of serial homologous neurons in the subesophageal ganglion of Tenebrio molitor (Insecta: Coleoptera)
Microscopy research and technique, 1996Co-Authors: Olaf Breidbach, Rolf UrbachAbstract:Neuroblast pattern, engrailed expression and proliferation in the subesophageal neuromers of the beetle Tenebrio molitor are characterized throughout embryogenesis. The proliferation of neuroblasts has been studied throughout postembyronic development. Serotonin, Crustacean Cardioactive Peptide and tyrosine hydroxylase-like-immunoreactive neurons are characterized and their neuronal development has been studied. There is an initial posterior-anterior gradient in neuroblast segregation leading to a reduced number of neuroblasts in the frontal subesophageal neuromer. The study of the engrailed expression shows that only the anterior subfraction of the neuromeral neuroblast configuration is reduced, whereas the posterior two rows of engrailed-positive neuroblasts are not affected during the first 40% of embryogenesis. The overall number of proliferations in the first subesophageal neuromer reaches only 30–50% of the value found in each of the other two neuromers. The analysis of serotonin and Crustacean Cardioactive Peptide immunoreactivity allows the identification of serial homologous neurons which persist from the early embryo to the adult stage. In the different gnathal neuromers, these neurons form structurally highly similar projection patterns, but show different extensions of their arborizations, corresponding to the relative size of each neuromer. Structural homologies between subesophageal and thoracic neuromers are discussed. © 1996 Wiley-Liss, Inc.
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Common general morphological pattern of Peptidergic neurons in the arachnid brain: Crustacean Cardioactive Peptide-immunoreactive neurons in the protocerebrum of seven arachnid species
Cell and Tissue Research, 1995Co-Authors: Olaf Breidbach, Heinrich Dircksen, Rainer WegerhoffAbstract:A polyclonal antiserum raised against Crustacean Cardioactive Peptide labels 14 clusters of immunoreactive neurons in the protocerebrum of the spiders Tegenaria atrica and Nephila clavipes , and the harvestman (opilionid) Rilaena triangularis . In all species, these clusters possess the same number of neurons, and share similar structural and topological characteristics. Two sets of bilateral symmetrical neurons associated with the optic lobes and the arachnid “central body” were analysed in detail, comparing the harvestman R. triangularis and the spiders Brachypelma albopilosa (Theraphosidae), Cupiennius salei (Lycosidae), Tegenaria atrica (Agelenidae), Meta segmentata (Metidae) and Nephila clavipes (Araneidae). Sixteen neurons have been identified that display markedly similar axonal pathways and arborization patterns in all species. These neurons are considered homologues in the opilionid and the araneid brains. We presume that these putative phylogenetically persisting neurons represent part of the general morphological pattern of the arachmid brain.
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Constancies in the neuronal architecture of the suboesophageal ganglion at metamorphosis in the beetleTenebrio molitor L.
Cell and Tissue Research, 1991Co-Authors: Olaf BreidbachAbstract:Topological organization of identified neurons has been characterized for the larval, pupal and imaginal suboeosphageal neuropil of the meal-worm beetle Tenebrio molitor . Neuronal fate mapping allows identification of individually persisting neurons in the metamorphosing suboesophageal ganglion of Tenebrio . Analysis was performed on interneurons characterized by serotonin and CCAP (Crustacean Cardioactive Peptide) immunohistochemistry, on motoneurons that innervate the dorsal and ventral longitudinal muscles, and on suboesophageal descending neurons. All these different populations of neurons show topologically invariant features throughout metamorphosis. Motoneurons, interneurons, and descending suboesophageal neurons of the imaginal suboeosphageal ganglion embody individually persisting larval interneurons. Impacts for a functional interpretation of the neuronal architecture of the suboesophageal ganglion are discussed.
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Crustacean Cardioactive Peptide-immunoreactive neurons in the ventral nerve cord and the brain of the meal beetle Tenebrio molitor during postembryonic development
Cell and Tissue Research, 1991Co-Authors: Olaf Breidbach, Heinrich DircksenAbstract:By use of an antiserum against the Crustacean Cardioactive Peptide (CCAP) several types of bilaterally symmetrical neurons have been mapped quantitatively in the ventral nerve cord and in the brain of the meal beetle, Tenebrio molitor . The general architecture of these neurons was reconstructed from peroxidase-antiperoxidase-labelled whole-mount preparations. From the subesophageal to the seventh abdominal ganglia two types of neurons show a repetitive organization of contralateral projection patterns in each neuromere. The first type has few branches in the central neuropil and a distinct peripheral projection. The second type is characterized by an elaborate central branching pattern, which includes ascending and descending processes. Some of its peripheral branches were found to supply peripheral neurohemal areas. In the protocerebrum, 10 CCAP-immunoreactive neurons occur with projections into the superior median protocerebrum and the tritocerebrum. Immunopositive neurons were mapped in larval and various pupal stages, as well as in the adult. All types of identified neurons were found to persist throughout metamorphosis maintaining their essential structural and topological characteristics. The CCAP-immunoreactive neurons of T. molitor are compared with those described for the locust. Putative structural homologies of subsets of neurons in both species are discussed.
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Constancies in the neuronal architecture of the suboesophageal ganglion at metamorphosis in the beetle Tenebrio molitor L.
Cell and Tissue Research, 1991Co-Authors: Olaf BreidbachAbstract:Topological organization of identified neurons has been characterized for the larval, pupal and imaginal suboeosphageal neuropil of the meal-worm beetleTenebrio molitor. Neuronal fate mapping allows identification of individually persisting neurons in the metamorphosing suboesophageal ganglion ofTenebrio. Analysis was performed on interneurons characterized by serotonin and CCAP (Crustacean Cardioactive Peptide) immunohistochemistry, on motoneurons that innervate the dorsal and ventral longitudinal muscles, and on suboesophageal descending neurons. All these different populations of neurons show topologically invariant features throughout metamorphosis. Motoneurons, interneurons, and descending suboesophageal neurons of the imaginal suboeosphageal ganglion embody individually persisting larval interneurons. Impacts for a functional interpretation of the neuronal architecture of the suboesophageal ganglion are discussed.
Lvping Zhang - One of the best experts on this subject based on the ideXlab platform.
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Crustacean Cardioactive Peptide (CCAP) of the Pacific white shrimp (Litopenaeus vannamei): Molecular characterization and its potential roles in osmoregulation and freshwater tolerance
Aquaculture, 2016Co-Authors: Ting Chen, Chunhua Ren, Yanhong Wang, Yan Gao, Nai-kei Wong, Lvping ZhangAbstract:Abstract Osmoregulation is one of the most fundamental and delicately controlled processes in euryhaline marine species like penaeid shrimp. Here we first report a cDNA encoding for the Crustacean Cardioactive Peptide (CCAP) precursor cloned from the intestine of Pacific white shrimp, Litopenaeus vannamei , a prominent commercial culture species. The CCAP mature Peptide (PFCNAFTGC-NH 2 ) is generated by post-translational processing and found to be highly comparable with its counterparts in insects and other Crustaceans. Semi-quantitative RT-PCR reveals that L. vannamei CCAP ( Lv-CCAP ) mRNA is predominantly expressed in the brain and intestine. However, only the expression level of intestine-derived Lv-CCAP mRNA showed responsiveness to salinity changes in culture. The inducible expressed Lv-CCAP mRNA by transfer to high-salinity condition was continuous, while mRNA expression stimulated by transfer to low-salinity condition was transient. Functionally, the stimulatory effects of CCAP on heart rates in the shrimp cultured in low- and normal-salinity conditions were confirmed. Furthermore, injection of CCAP could up-regulate the freshwater tolerance of shrimp by increasing their survival rates. Our study, as a whole, provides new insights into hormone-regulated Crustacean osmostasis and may prove instructive to the inland freshwater penaeid shrimp aquaculture. State of relevance It proves instructive to freshwater shrimp aquaculture.
David C. Wilcockson - One of the best experts on this subject based on the ideXlab platform.
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Transcriptomic analysis of Crustacean neuroPeptide signaling during the moult cycle in the green shore crab, Carcinus maenas
BMC genomics, 2018Co-Authors: Andrew Oliphant, Simon G. Webster, Jodi L. Alexander, Martin T. Swain, David C. WilcocksonAbstract:Ecdysis is an innate behaviour programme by which all arthropods moult their exoskeletons. The complex suite of interacting neuroPeptides that orchestrate ecdysis is well studied in insects, but details of the Crustacean ecdysis cassette are fragmented and our understanding of this process is comparatively crude, preventing a meaningful evolutionary comparison. To begin to address this issue we identified transcripts coding for neuroPeptides and their putative receptors in the central nervous system (CNS) and Y-organs (YO) within the crab, Carcinus maenas, and mapped their expression profiles across accurately defined stages of the moult cycle using RNA-sequencing. We also studied gene expression within the epidermally-derived YO, the only defined role for which is the synthesis of ecdysteroid moulting hormones, to elucidate Peptides and G protein-coupled receptors (GPCRs) that might have a function in ecdysis. Transcriptome mining of the CNS transcriptome yielded neuroPeptide transcripts representing 47 neuroPeptide families and 66 putative GPCRs. NeuroPeptide transcripts that were differentially expressed across the moult cycle included carcikinin, Crustacean hyperglycemic hormone-2, and Crustacean Cardioactive Peptide, whilst a single putative neuroPeptide receptor, proctolin R1, was differentially expressed. Carcikinin mRNA in particular exhibited dramatic increases in expression pre-moult, suggesting a role in ecdysis regulation. Crustacean hyperglycemic hormone-2 mRNA expression was elevated post- and pre-moult whilst that for Crustacean Cardioactive Peptide, which regulates insect ecdysis and plays a role in stereotyped motor activity during Crustacean ecdysis, was elevated in pre-moult. In the YO, several putative neuroPeptide receptor transcripts were differentially expressed across the moult cycle, as was the mRNA for the neuroPeptide, neuroparsin-1. Whilst differential gene expression of putative neuroPeptide receptors was expected, the discovery and differential expression of neuroPeptide transcripts was surprising. Analysis of GPCR transcript expression between YO and epidermis revealed 11 to be upregulated in the YO and thus are now candidates for Peptide control of ecdysis. The data presented represent a comprehensive survey of the deduced C. maenas neuropeptidome and putative GPCRs. Importantly, we have described the differential expression profiles of these transcripts across accurately staged moult cycles in tissues key to the ecdysis programme. This study provides important avenues for the future exploration of functionality of receptor-ligand pairs in Crustaceans.
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Transcriptomic analysis of Crustacean neuroPeptide signaling during the moult cycle in the green shore crab, Carcinus maenas
BMC Genomics, 2018Co-Authors: Andrew Oliphant, Simon G. Webster, Jodi L. Alexander, Martin T. Swain, David C. WilcocksonAbstract:Background Ecdysis is an innate behaviour programme by which all arthropods moult their exoskeletons. The complex suite of interacting neuroPeptides that orchestrate ecdysis is well studied in insects, but details of the Crustacean ecdysis cassette are fragmented and our understanding of this process is comparatively crude, preventing a meaningful evolutionary comparison. To begin to address this issue we identified transcripts coding for neuroPeptides and their putative receptors in the central nervous system (CNS) and Y-organs (YO) within the crab, Carcinus maenas, and mapped their expression profiles across accurately defined stages of the moult cycle using RNA-sequencing. We also studied gene expression within the epidermally-derived YO, the only defined role for which is the synthesis of ecdysteroid moulting hormones, to elucidate Peptides and G protein-coupled receptors (GPCRs) that might have a function in ecdysis. Results Transcriptome mining of the CNS transcriptome yielded neuroPeptide transcripts representing 47 neuroPeptide families and 66 putative GPCRs. NeuroPeptide transcripts that were differentially expressed across the moult cycle included carcikinin, Crustacean hyperglycemic hormone-2, and Crustacean Cardioactive Peptide, whilst a single putative neuroPeptide receptor, proctolin R1, was differentially expressed. Carcikinin mRNA in particular exhibited dramatic increases in expression pre-moult, suggesting a role in ecdysis regulation. Crustacean hyperglycemic hormone-2 mRNA expression was elevated post- and pre-moult whilst that for Crustacean Cardioactive Peptide, which regulates insect ecdysis and plays a role in stereotyped motor activity during Crustacean ecdysis, was elevated in pre-moult. In the YO, several putative neuroPeptide receptor transcripts were differentially expressed across the moult cycle, as was the mRNA for the neuroPeptide, neuroparsin-1. Whilst differential gene expression of putative neuroPeptide receptors was expected, the discovery and differential expression of neuroPeptide transcripts was surprising. Analysis of GPCR transcript expression between YO and epidermis revealed 11 to be upregulated in the YO and thus are now candidates for Peptide control of ecdysis. Conclusions The data presented represent a comprehensive survey of the deduced C. maenas neuropeptidome and putative GPCRs. Importantly, we have described the differential expression profiles of these transcripts across accurately staged moult cycles in tissues key to the ecdysis programme. This study provides important avenues for the future exploration of functionality of receptor-ligand pairs in Crustaceans.
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Identification and developmental expression of mRNAs encoding Crustacean Cardioactive Peptide (CCAP) in decapod Crustaceans
Journal of Experimental Biology, 2006Co-Authors: J S Chung, Heinrich Dircksen, David C. Wilcockson, N. Zmora, Y. Zohar, Simon G. WebsterAbstract:Full-length cDNAs encoding Crustacean Cardioactive Peptide (CCAP) were isolated from several decapod (brachyuran and astacuran) Crustaceans: the blue crab Callinectes sapidus, green shore crab Carcinus maenas, European lobster Homarus gamarus and calico crayfish Orconectes immunis. The cDNAs encode open reading frames of 143 (brachyurans) and 139-140 (astacurans) amino acids. Apart from the predicted signal Peptides (30-32 amino acids), the conceptually translated precursor codes for a single copy of CCAP and four other Peptides that are extremely similar in terms of amino acid sequence within these species, but which clearly show divergence into brachyuran and astacuran groups. Expression patterns of CCAP mRNA and Peptide were determined during embryonic development in Carcinus using quantitative RT-PCR and immunohistochemistry with whole-mount confocal microscopy, and showed that significant mRNA expression (at 50% embryonic development) preceded detectable levels of CCAP in the developing central nervous system (CNS; at 70% development). Subsequent CCAP gene expression dramatically increased during the late stages of embryogenesis (80-100%), coincident with developing immunopositive structures. In adult crabs, CCAP gene expression was detected exclusively in the eyestalk, brain and in particular the thoracic ganglia, in accord with the predominance of CCAP-containing cells in this tissue. Measurement of expression patterns of CCAP mRNA in Carcinus and Callinectes thoracic ganglia throughout the moult cycle revealed only modest changes, indicating that previously observed increases in CCAP Peptide levels during premoult were not transcriptionally coupled. Severe hypoxic conditions resulted in rapid downregulation of CCAP transcription in the eyestalk, but not the thoracic ganglia in Callinectes, and thermal challenge did not change CCAP mRNA levels. These results offer the first tantalising glimpses of involvement of CCAP in environmental adaptation to extreme, yet biologically relevant stressors, and perhaps suggest that the CCAP-containing neurones in the eyestalk might be involved in adaptation to environmental stressors.