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McGrath LL, Vollmer SV, Kaluziak ST, Ayers J. De novo transcriptome assembly for the lobster Homarus americanus and characterization of differential gene expression across nervous system tissues. BMC Genomics 2016; 17:63. [PMID: 26772543 PMCID: PMC4715275 DOI: 10.1186/s12864-016-2373-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 01/06/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The American lobster, Homarus americanus, is an important species as an economically valuable fishery, a key member in marine ecosystems, and a well-studied model for central pattern generation, the neural networks that control rhythmic motor patterns. Despite multi-faceted scientific interest in this species, currently our genetic resources for the lobster are limited. In this study, we de novo assemble a transcriptome for Homarus americanus using central nervous system (CNS), muscle, and hybrid neurosecretory tissues and compare gene expression across these tissue types. In particular, we focus our analysis on genes relevant to central pattern generation and the identity of the neurons in a neural network, which is defined by combinations of genes distinguishing the neuronal behavior and phenotype, including ion channels, neurotransmitters, neuromodulators, receptors, transcription factors, and other gene products. RESULTS Using samples from the central nervous system (brain, abdominal ganglia), abdominal muscle, and heart (cardiac ganglia, pericardial organs, muscle), we used RNA-Seq to characterize gene expression patterns across tissues types. We also compared control tissues with those challenged with the neuropeptide proctolin in vivo. Our transcriptome generated 34,813 transcripts with known protein annotations. Of these, 5,000-10,000 of annotated transcripts were significantly differentially expressed (DE) across tissue types. We found 421 transcripts for ion channels and identified receptors and/or proteins for over 20 different neurotransmitters and neuromodulators. Results indicated tissue-specific expression of select neuromodulator (allostatin, myomodulin, octopamine, nitric oxide) and neurotransmitter (glutamate, acetylcholine) pathways. We also identify differential expression of ion channel families, including kainite family glutamate receptors, inward-rectifying K(+) (IRK) channels, and transient receptor potential (TRP) A family channels, across central pattern generating tissues. CONCLUSIONS Our transcriptome-wide profiles of the rhythmic pattern generating abdominal and cardiac nervous systems in Homarus americanus reveal candidates for neuronal features that drive the production of motor output in these systems.
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Affiliation(s)
- Lara Lewis McGrath
- Northeastern University Marine Science Center, 430 Nahant Rd, Nahant, MA, 01908, USA. .,Current address: AstraZeneca, 35 Gatehouse Dr, Waltham, MA, 02451, USA.
| | - Steven V Vollmer
- Northeastern University Marine Science Center, 430 Nahant Rd, Nahant, MA, 01908, USA.
| | - Stefan T Kaluziak
- Northeastern University Marine Science Center, 430 Nahant Rd, Nahant, MA, 01908, USA.
| | - Joseph Ayers
- Northeastern University Marine Science Center, 430 Nahant Rd, Nahant, MA, 01908, USA.
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Burnett KG, Burnett LE. Respiratory and Metabolic Impacts of Crustacean Immunity: Are there Implications for the Insects? Integr Comp Biol 2015. [DOI: 10.1093/icb/icv094] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Christie AE, Stevens JS, Bowers MR, Chapline MC, Jensen DA, Schegg KM, Goldwaser J, Kwiatkowski MA, Pleasant TK, Shoenfeld L, Tempest LK, Williams CR, Wiwatpanit T, Smith CM, Beale KM, Towle DW, Schooley DA, Dickinson PS. Identification of a calcitonin-like diuretic hormone that functions as an intrinsic modulator of the American lobster, Homarus americanus, cardiac neuromuscular system. ACTA ACUST UNITED AC 2010; 213:118-27. [PMID: 20008368 DOI: 10.1242/jeb.037077] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In insects, a family of peptides with sequence homology to the vertebrate calcitonins has been implicated in the control of diuresis, a process that includes mixing of the hemolymph. Here, we show that a member of the insect calcitonin-like diuretic hormone (CLDH) family is present in the American lobster, Homarus americanus, serving, at least in part, as a powerful modulator of cardiac output. Specifically, during an ongoing EST project, a transcript encoding a putative H. americanus CLDH precursor was identified; a full-length cDNA was subsequently cloned. In silico analyses of the deduced prepro-hormone predicted the mature structure of the encoded CLDH to be GLDLGLGRGFSGSQAAKHLMGLAAANFAGGPamide (Homam-CLDH), which is identical to a known Tribolium castaneum peptide. RT-PCR tissue profiling suggests that Homam-CLDH is broadly distributed within the lobster nervous system, including the cardiac ganglion (CG), which controls the movement of the neurogenic heart. RT-PCR analysis conducted on pacemaker neuron- and motor neuron-specific cDNAs suggests that the motor neurons are the source of the CLDH message in the CG. Perfusion of Homam-CLDH through the isolated lobster heart produced dose-dependent increases in both contraction frequency and amplitude and a dose-dependent decrease in contraction duration, with threshold concentrations for all parameters in the range 10(-11) to 10(-10) mol l(-1) or less, among the lowest for any peptide on this system. This report is the first documentation of a decapod CLDH, the first demonstration of CLDH bioactivity outside the Insecta, and the first detection of an intrinsic neuropeptide transcript in the crustacean CG.
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Affiliation(s)
- A E Christie
- Center for Marine Functional Genomics, Mount Desert Island Biological Laboratory, PO Box 35, Old Bar Harbor Road, Salisbury Cove, ME 04672, USA.
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Maurer G, Wilkens JL, Grieshaber MK. Modulatory effects of adenosine and adenine nucleotides on different heart preparations of the American lobster, Homarus americanus. ACTA ACUST UNITED AC 2008; 211:661-70. [PMID: 18281328 DOI: 10.1242/jeb.011478] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
As shown previously, adenosine and the adenine nucleotides cause a rapid increase in heart rate (f(H)) and haemolymph velocity (v(HL)) when infused into intact American lobster (Homarus americanus). Here we compare the effects of adenosine and adenine nucleotides on different heart preparations in order to gain insight into their sites of action. In the semi-isolated (in situ) heart preparation where the heart is uncoupled from neural and hormonal influence AMP, ADP and ATP, but not adenosine increased contractile force. None of the purines altered f(H). Thus, the adenine nucleotides directly affect the myocardium and not the f(H)-setting cardiac ganglion. In cardioregulatory-denervated animals in which the cardiac ganglion only was severed from the central nervous system (CNS), purines caused a small and gradual increase in f(H), indicating that in vivo an alteration of f(H) arises indirectly through the central nervous system which in turn sends the information to the heart via the dorsal nerves. The gradual increase in f(H) of cardioregulatory-denervated animals may also result from neurohormones released into the circulatory system, although no significant changes in haemolymph concentration of dopamine, serotonin and octopamine were found during adenosine infusion. In semi-isolated (in situ) hearts adenine nucleotides also increased haemolymph flow, as a consequence of increased heart contractile force, but again adenosine had no effect. These data show that in vivo adenosine does not influence the myocardium, only the adenine nucleotides affect the myocardium directly. Obviously adenosine possesses an indirect effect, perhaps on cardio-arterial valves and arterial resistance, but other, as yet unidentified, modifying factors are also possible.
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Affiliation(s)
- Gereon Maurer
- Institut für Zoophysiologie, Heinrich-Heine-Universität, Universitätsstrasse 1, Düsseldorf, Germany.
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Genovese G, Senek M, Ortiz N, Regueira M, Towle DW, Tresguerres M, Luquet CM. Dopaminergic regulation of ion transport in gills of the euryhaline semiterrestrial crabChasmagnathus granulatus: interaction between D1- and D2-like receptors. J Exp Biol 2006; 209:2785-93. [PMID: 16809469 DOI: 10.1242/jeb.02308] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYThe effects of dopamine (DA) and dopaminergic agonists and antagonists on ion transport were studied in isolated perfused gills of the crab Chasmagnathus granulatus. DA applied under steady state conditions(perfusion with hemolymph-like saline) produced a transient increase of the transepithelial potential difference (Vte) from 2.2±0.2 to 4.8±0.3 mV, describing an initial cAMP-dependent stimulating phase followed by an inhibitory phase. Spiperone and domperidone(antagonists of D2-like DA receptors in vertebrates) completely blocked the response to DA, while the D1-like antagonist SCH23390 blocked only the inhibitory phase. Theophylline (phosphodiesterase inhibitor) and okadaic acid(protein phosphatases PP1 and PP2A inhibitor) were also able to block the inhibitory phase, suggesting that it depends on adenylyl cyclase inhibition and on protein phosphatases. When the gills were perfused with hypo-osmotic solution, or with the adenylyl cyclase activator forskolin, Vte was increased several-fold. DA applied under these stimulated conditions partially reversed the Vte increase by 54% and 25%, respectively. Similarly, the D1-like agonist, fenoldopam,produced a 33% reduction in the stimulated Vte. We propose that, in C. granulatus gills, DA stimulates adenylyl cyclase and therefore ion transport through D1-like receptors linked to a Gs protein,although they respond to antagonists that interact with D2-like receptors in vertebrates. The inhibitory phase seems to be mediated by D2-like receptors linked to a Gi/o protein, which inhibits adenylyl cyclase, although these receptors can be activated or blocked by agonists or antagonists that interact with D1-like receptors in vertebrates and insects.
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Affiliation(s)
- Griselda Genovese
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria (C1428EHA), Buenos Aires, Argentina.
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Worden MK, Clark CM, Conaway M, Qadri SA. Temperature dependence of cardiac performance in the lobster Homarus americanus. ACTA ACUST UNITED AC 2006; 209:1024-34. [PMID: 16513928 DOI: 10.1242/jeb.02082] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The lobster Homarus americanus inhabits ocean waters that vary in temperature over a 25 degrees C range, depending on the season and water depth. To investigate whether the lobster heart functions effectively over a wide range of temperatures we examine the temperature dependence of cardiac performance of isolated lobster hearts in vitro. In addition, we examined whether modulation of the heart by serotonin depends on temperature. The strength of the heartbeat strongly depends on temperature, as isolated hearts are warmed from 2 to 22 degrees C the contraction amplitude decreases by greater than 60%. The rates of contraction and relaxation of the heart are most strongly temperature dependent in the range from 2 to 4 degrees C but become temperature independent at warmer temperatures. Heart rates increase as a function of temperature both in isolated hearts and in intact animals, however hearts in intact animals beat faster in the temperature range of 12-20 degrees C. Interestingly, acute Q10 values for heart rate are similar in vivo and in vitro over most of the temperature range, suggesting that temperature dependence of heart rate arises mainly from the temperature effects on the cardiac ganglion. In contrast to earlier reports suggesting that the strength and the frequency of the lobster heartbeat are positively correlated, we observe no consistent relationship between these parameters as they change as a function of temperature. Stroke volume decreases as a function of temperature. However, the opposing temperature-dependent increase in heart rate partially compensates to produce a relationship between cardiac output and temperature in which cardiac output is maximal at 10 degrees C and significantly decreases above 20 degrees C. Serotonin potentiates contraction amplitude and heart rate in a temperature-independent manner. Overall, our results show that although the parameters underlying cardiac performance show different patterns of temperature dependence, cardiac output remains relatively constant over most of the wide range of environmental temperatures the lobster inhabits in the wild.
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Affiliation(s)
- Mary Kate Worden
- Department of Neuroscience, University of Virginia, PO 801392, Charlottesville, VA 22908, USA.
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F -Tsukamoto Y, Kuwasawa K. Neurohormonal and glutamatergic neuronal control of the cardioarterial valves in the isopod crustacean Bathynomus doederleini. J Exp Biol 2003; 206:431-43. [PMID: 12502764 DOI: 10.1242/jeb.00077] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The heart of Bathynomus doederleini gives rise to an anterior median artery (AMA), one pair of anterior lateral arteries (ALAs) and five pairs of lateral arteries (LAs). Cardioarterial valves are located at the junctions between the heart and arteries, each composed of a pair of muscular flaps. All valves of the AMA and the ALAs receive valve excitatory (constrictor) nerves (VEs). The valves of the ALAs receive dual innervation from both constrictor and inhibitor (dilator) nerves, while the valves of the AMA receive innervation from a constrictor nerve alone. The effects of candidate neurohormones on cardioarterial valves were examined by measuring the pressure in each artery at which haemolymph flows out of the heart through the valve. Serotonin, octopamine, norepinephrine, glutamate (Glu) and proctolin constricted the cardioarterial valves and thus decreased the arterial pressure in all the arteries. Dopamine also decreased the arterial pressure of arteries except for the ALAs, in which pressure was increased. Among the neurohormones exerting excitatory effects on the valves, only Glu depolarized the membrane potential of valve muscle cells. The glutamatergic agonists kainate and quisqualate also depolarized the valve muscle cells of the AMA. Excitatory junctional potentials produced in the valves of the AMA in response to the stimulation of a VE were blocked by the glutamatergic antagonists Joro spider toxin and MK-801. Glu is the likeliest candidate for a neurotransmitter for the VEs.
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Affiliation(s)
- Yoko F -Tsukamoto
- Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minami-ohsawa, Hachioji 192-0397, Japan
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Saver MA, Wilkens JL, Syed NI. In situ and in vitro identification and characterization of cardiac ganglion neurons in the crab, Carcinus maenas. J Neurophysiol 1999; 81:2964-76. [PMID: 10368413 DOI: 10.1152/jn.1999.81.6.2964] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The aim of this study was to investigate the intrinsic membrane properties and hormonal responses of individual central pattern generating neurons in the cardiac ganglion of the shore crab Carcinus maenas. Because the cardiac ganglion in this crustacean species is buried within the heart musculature and is therefore inaccessible for direct morphological and electrophysiological analysis, we developed two novel in vitro preparations. First, to make the ganglion accessible, we established a brief enzymatic treatment procedure that enabled us to isolate the entire cardiac ganglion, in the absence of muscle tissue. Second, a cell culture procedure was developed to isolate individual neurons in vitro. With the use of both isolated ganglionic and neuronal cell culture techniques, this study provides the first direct account of the neuroanatomy of the cardiac ganglion in shore crabs. We demonstrate that cultured neurons not only survived the isolation procedures, but that they also maintained their intrinsic membrane and transmitter response properties, similar to those seen in the intact ganglion. Specifically, we tested the peptides proctolin, crustacean cardioactive peptide, the FLRFamide-related peptide F2, and an amine (serotonin) on both isolated ganglion and in vitro culture neurons. We measured changes in neuronal burst rate, burst amplitude, pacemaker slope, and membrane potential oscillation amplitude in response to the above four hormones. Each hormone either increased neuronal activity in spontaneously bursting neurons, or induced a bursting pattern in quiescent cells. The in vitro cell culture system developed here now provides us with an excellent opportunity to elucidate cellular, synaptic and hormonal mechanisms by which cardiac activity is generated in shore crabs.
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Affiliation(s)
- M A Saver
- Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
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