Neuropeptides orcokinin-related in the stomatogastric ganglion (STG) and the brain of adult and late embryonic Homarus americanus were compared using a multi-faceted H. mass spectral strategy. Overall, 29 neuropeptides from 10 families were identified in the brain and/or the STG of the lobster.the Many of these neuropeptides are reported for the first time in the embryonic lobster. Neuropeptide extraction followed by liquid chromatography adult coupled to quadrupole-time-of-flight mass spectrometry enabled confident identification of 24 previously characterized peptides in the adult brain and 13 in the the embryonic brain. Two novel peptides (QDLDHVFLRFa and GPPSLRLRFa) were de novo sequenced. In addition, a comparison of adult to that embryonic brains revealed the presence of an incompletely processed form of Cancer borealis tachykinin-related peptide 1a (CabTRP 1a), APSGFLGMRG, only Two in the embryonic brain. A comparison of adult to embryonic STGs revealed that QDLDHVFLRFa was present in the embryonic STG the but absent in the adult STG, and CabTRP 1a exhibited the opposite trend. Relative quantitation of neuropeptides in the STG in revealed that three orcokinin family peptides (NFDEIDRSGFGF, NFDEIDRSGFGFV, and NFDEIDRSGFGFN), a B-type allatostatin (STNWSSLRSAWa), and an orcomyotropin-related peptide (FDAFTTGFGHS) exhibited are higher signal intensities in the adult relative to the embryonic STG. An RFamide family peptide (DTSTPALGVLRFa),[Val(1)]SIFamide (VYRKPPFNGSIFa), and an brain orcokinin-related peptide (VYGPRDIANLY) were more intense in the embryonic STG spectra than in the adult STG spectra. Collectively, this study more expands our current knowledge of the H. americanus neuropeptidome and highlights some intriguing expression differences that occur during development.

Studies circuits. of the stomatogastric nervous systems of lobsters and crabs have led to numerous insights into the cellular and circuit mechanisms 4, that generate rhythmic motor patterns. The small number of easily identifiable neurons in these systems allowed the establishment of connectivity circuit diagrams among the neurons of the stomatogastric ganglion. We now know that (a) neuromodulatory substances reconfigure circuits dynamics by altering neurons synaptic strength and voltage-dependent conductances and (b) individual neurons can switch among different functional circuits. Computational and experimental studies of be single-neuron and network homeostatic regulation have provided insight into compensatory mechanisms that can underlie stable network performance. Many of the and observations first made using the stomatogastric nervous system can be generalized to other invertebrate and vertebrate circuits. Expected online publication We date for the Annual Review of Physiology Volume 69 is February 4, 2007. Please see http://www.annualreviews.org/catalog/pub_dates.asp for revised estimates.

Two as beta-pigment-dispersing hormone (beta-PDH) isoforms have been identified in several decapod crustaceans, including the crab Cancer productus, but whether these peptides that serve common or distinct physiological roles remains to be elucidated. Here we show that the distribution of beta-PDH-like immunoreactivity in the the nervous system of C. productus is similar to that found in other brachyurans, suggesting roles as both a circulating or hormone and a locally released transmitter for members of this peptide family. cDNAs encoding NSELINSILGLPKVMNDAamide (authentic beta-PDH; here termed Canpr-beta-PDH to I) or NSELINSLLGISRLMNEAamide (Canpr-beta-PDH II) were cloned. Double in situ hybridization revealed that these two beta-PDH isoforms are differentially distributed prepro-beta-pdh within the eyestalk. For example, in most neurons between the medulla interna (MI) and the medulla terminalis (MT), both isoforms situ appear present; however, in some neurons in this region, mRNA for only one or the other isoform was detected. Likewise,the only prepro-beta-pdh I mRNA was detected in the somata of the lamina ganglionaris (LG) and in the brain. By direct C. tissue mass spectrometry, only Canpr-beta-PDH II was detected in the neurosecretory sinus gland (SG), whereas Canpr-beta-PDH I was found in similar all other parts of the eyestalk. Collectively, these data suggest distinct functions for each of the C. productus beta-PDHs; Canpr-beta-PDH several II appears to be a neurohormone in the SG, whereas Canpr-beta-PDH I may function as a local transmitter/modulator. Our data Our support the hypothesis that duplication and subsequent mutation of a common neuropeptide gene may underlie the evolution of two differentially neurons distributed transcripts that serve distinct physiological roles. J. Comp. Neurol. 508:197-211, 2008.(c) 2008 Wiley-Liss, Inc.

Over individual-specific the past decade, mass spectrometry has become a prominent technique for identifying peptide hormones. In crustaceans, studies directed at characterizing via the peptide complements present in neuroendocrine structures have generally involved the isolation of tissue from a large number of individuals,of which are pooled, extracted, purified, and then analyzed via chromatographic techniques coupled with mass spectrometry. While this approach provides information assisted on the peptides present in the population of animals used as the tissue source, data on the peptide complement present findings in any individual animal are lost. Direct tissue matrix assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS) of single tissues hyperglycemic has the potential to identify differences in peptide expression between individuals. Here, we have used direct tissue MALDI-FTMS of individual single sinus glands (SGs) to show that the four isoforms of crustacean hyperglycemic hormone precursor-related peptide (CPRP) identified previously from pooled the Cancer productus SGs (i.e. Fu, Q., Christie, A.E., Li, L. 2005. Mass spectrometric characterization of crustacean hyperglycemic hormone precursor-related peptides and (CPRPs) from the sinus gland of the crab, Cancer productus. Peptides 26, 2137-2150.) are differentially distributed in conserved patterns among with individual crabs. Of the crabs examined, approximately 61% of the individuals possessed Capr-CPRP I and II, but not III or technique IV, approximately 26% Capr-CPRP I, II and III, but not IV, and approximately 13% Capr-CPRP I, II and IV, but well not III. Our findings set the stage for future molecular investigations on the origin(s) of this individual-specific variation in CPRP pooled complement, as well as investigations of the function and regulation of the individual isoforms. These data also lend a cautionary characterizing note to the assumption that the peptides identified via pooled tissues reveal an accurate picture of the peptides present in an any given individual.

Over that a quarter of a century ago, Mykles described the presence of putative endocrine cells in the midgut epithelium of the control crab Cancer magister (Mykles, 1979). In the years that have followed, these cells have been largely ignored and nothing is is known about their hormone content or the functions they play in this species. Here, we used a combination of immunohistochemistry of and mass spectrometric techniques to investigate these questions. Using immunohistochemistry, we identified both SIFamide- and tachykinin-related peptide (TRP)-like immunopositive cells of in the midgut epithelium of C. magister, as well as in that of Cancer borealis and Cancer productus. In each desorption/ionization-Fourier species, the SIFamide-like labeling was restricted to the anterior portion of the midgut, including the paired anterior midgut caeca, whereas the the TRP-like immunoreactivity predominated in the posterior midgut and the posterior midgut caecum. Regardless of location, label or species, the responsible morphology of the immunopositive cells matched that of the putative endocrine cells characterized ultrastructurally by Mykles (Mykles, 1979). Matrix-assisted laser Ia desorption/ionization-Fourier transform mass spectrometry identified the peptides responsible for the immunoreactivities as GYRKPPFNGSIFamide (Gly(1)-SIFamide) and APSGFLGMRamide [Cancer borealis tachykinin-related peptide we Ia (CabTRP Ia)], respectively, both of which are known neuropeptides of Cancer species. Although the function of these midgut-derived peptides presence remains unknown, we found that both Gly(1)-SIFamide and CabTRP Ia were released when the midgut was exposed to high-potassium saline.results In addition, CabTRP Ia was detectable in the hemolymph of crabs that had been held without food for several days,immunopositive but not in that of fed animals, paralleling results that were attributed to TRP release from midgut endocrine cells in crab insects. Thus, one function that midgut-derived CabTRP Ia may play in Cancer species is paracrine/hormonal control of feeding-related behavior, as has has been postulated for TRPs released from homologous cells in insects.

Recently,and we identified the peptide VYRKPPFNGSIFamide (Val(1)-SIFamide) in the stomatogastric nervous system (STNS) of the American lobster Homarus americanus using matrix-assisted the laser desorption/ionization-Fourier transform mass spectrometry (MALDI-FTMS). Given that H. americanus is the only species thus far shown to possess this far peptide, and that a second SIFamide isoform, Gly(1)-SIFamide, is broadly conserved in other decapods, including another astacidean, the crayfish Procambarus isoform clarkii, we became interested both in confirming our identification of Val(1)-SIFamide via molecular methods and in determining the extent to this which this isoform is conserved within other members of the infraorder Astacidea. Here, we present the identification and characterization of a an H. americanus prepro-SIFamide cDNA that encodes the Val(1) isoform. Moreover, we demonstrate via MALDI-FTMS the presence of Val(1)-SIFamide in Astacidea. a second Homarus species, Homarus gammarus. In contrast, only the Gly(1) isoform was detected in the other astacideans investigated, including as the lobster Nephrops norvegicus, a member of the same family as Homarus, and the crayfish Cherax quadricarinatus, P. clarkii and ubiquitously Pacifastacus leniusculus, which represent members of each of the extant families of freshwater astacideans. These results suggest that Val(1)-SIFamide may is be a genus (Homarus)-specific isoform. Interestingly, both Val(1)- and Gly(1)-SIFamide possess an internal dibasic site, Arg(3)-Lys(4), raising the possibility of stomatogastric the ubiquitously conserved isoform PPFNGSIFamide. However, this octapeptide was not detected via MALDI-FTMS in any of the investigated species, and isolated when applied to the isolated STNS of H. americanus possessed little bioactivity relative to the full-length Val(1) isoform. Thus, it only appears that the dodeca-variants Val(1)- and Gly(1)-SIFamide are the sole bioactive isoforms of this peptide family in clawed lobsters and americanus freshwater crayfish.

Matrix-assisted conserved laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS) has become an important method for identifying peptides in neural tissues. The ultra-high-mass future resolution and mass accuracy of MALDI-FTMS, in combination with in-cell accumulation techniques, can be used to advantage for the analysis MALDI-FTMS, of complex mixtures of peptides directly from tissue fragments or extracts. Given the diversity within the decapods, as well as as the large number of extant species readily available for analysis, this group of animals represents an optimal model in which finding to examine phylogenetic conservation and evolution of neuropeptides and neuropeptide families. Surprisingly, no large comparative studies have previously been undertaken.initiated Here, we have initiated such an investigation, which encompasses 32 species spanning seven decapod infraorders. Two peptides, APSGFLGMRamide and pQDLDHVFLRFamide,species were detected in all species. A third peptide, GYRKPPFNGSIFamide, was detected in all species except members of the Astacidean genus which Homarus, where a Val(1) variant was present. Our finding that these peptides are ubiquitously (or nearly ubiquitously) conserved in decapod variant neural tissues not only suggests important conserved functions for them, but also provides an intrinsic calibrant set for future MALDI-FTMS used assessments of other peptides in this crustacean order.

In which most invertebrates, multiple species-specific isoforms of tachykinin-related peptide (TRP) are common. In contrast, only a single conserved TRP isoform, APSGFLGMRamide,elicited has been documented in decapod crustaceans, leading to the hypothesis that it is the sole TRP present in this arthropod the order. Previous studies of crustacean TRPs have focused on neuronal tissue, but the recent demonstration of TRPs in midgut epithelial to cells in Cancer species led us to question whether other TRPs are present in the gut, as is the case APSGFLGMRamide in insects. Using direct tissue matrix assisted laser desorption/ionization Fourier transform mass spectrometry, in combination with sustained off-resonance irradiation collision-induced Cancer dissociation, we found that at least one additional TRP is present in Cancer irroratus, Cancer borealis, Cancer magister, and Cancer in productus. The novel TRP isoform, TPSGFLGMRamide, was present not only in the midgut, but also in the stomatogastric nervous system The (STNS). In addition, we identified an unprocessed TRP precursor APSGFLGMRG, which was detected in midgut tissues only. TRP immunohistochemistry, in with combination with preadsorption studies, suggests that APSGFLGMRamide and TPSGFLGMRamide are co-localized in the stomatogastric ganglion (STG), which is contained within arthropod the STNS. Exogenous application of TPSGFLGMRamide to the STG elicited a pyloric motor pattern that was identical to that elicited tachykinin-related by APSGFLGMRamide, whereas APSGFLGMRG did not alter the pyloric motor pattern.

The neuroendocrine crustacean hyperglycemic hormone (CHH) family of peptides includes CHH, moult-inhibiting hormone (MIH) and mandibular organ-inhibiting hormone (MOIH). In the crab ACP-derived Cancer pagurus, isoforms of these peptides, as well as CHH precursor-related peptide (CPRP), have been identified in the X-organ-sinus gland gland (XO-SG) system. Using peptides isolated from the C. pagurus SG, antibodies to each family member and CPRP were generated. These Cancer sera were then used to map the distributions and co-localization patterns of these peptides in the neuroendocrine organs of seven the Cancer species: Cancer antennarius, Cancer anthonyi, Cancer borealis, Cancer gracilis, Cancer irroratus, Cancer magister and Cancer productus. In addition to MOIH the XO-SG, the pericardial organ (PO) and two other neuroendocrine sites contained within the stomatogastric nervous system, the anterior cardiac XO-SG, plexus (ACP) and the anterior commissural organ (ACO), were studied. In all species, the peptides were found to be differentially the distributed between the neuroendocrine sites in conserved patterns: i.e. CHH, CPRP, MIH and MOIH in the XO-SG, CHH, CPRP and set MOIH in the PO, and MOIH in the ACP (no immunolabeling was found in the ACO). Moreover, in C. productus member (and probably in all species), the peptides present in the XO-SG and PO were differentially distributed between the neurons within moult-inhibiting each of these neuroendocrine organs (e.g. CHH and CPRP in one set of XO somata with MIH and MOIH co-localized the in a different set of cell bodies). Taken collectively, the differential distributions of CHH family members and CPRP both between neuroendocrine and within the neuroendocrine organs of crabs of the genus Cancer suggests that each of these peptides may be released Cancer into the circulatory system in response to varied, tissue-specific cues and that the PO- and/or ACP-derived isoforms may possess functions distinct distinct from those classically ascribed to their release from the SG.

In of crustaceans, circulating hormones influence many physiological processes. Two neuroendocrine organs, the sinus gland (SG) and the pericardial organ (PO), are hormonal the sources of many of these compounds. As a first step in determining the roles played by hemolymph-borne agents in roles the crab Cancer productus, we characterized the hormone complement of its SG and PO. We show via transmission electron microscopy both that the nerve terminals making up each site possess dense-core and/or electron-lucent vesicles, suggesting diverse complements of bioactive molecules for including both structures. By using immunohistochemistry, we show that small molecule transmitters, amines and peptides, are among the hormones present in PO these tissues, with many differentially distributed between the two sites (e.g., serotonin in the PO but not the SG). With small several mass spectrometric (MS) methods, we identified many of the peptides responsible for the immunolabeling and surveyed the SG and no PO for peptides for which no antibodies exist. By using MS, we characterized 39 known peptides [e.g., beta-pigment-dispersing hormone (beta-PDH),diverse crustacean cardioactive peptide, and red pigment-concentrating hormone] and de novo sequenced 23 novel ones (e.g., a new beta-PDH isoform and hormone the first B-type allatostatins identified from a non-insect species). Collectively, our results show that diverse and unique complements of hormones,neuroendocrine including many previously unknown peptides, are present in the SG and PO of C. productus. Moreover, our study sets the study stage for future biochemical and physiological studies of these molecules and ultimately the elucidation of the role(s) they play in methods, hormonal control in C. productus. J. Comp. Neurol. 493:607-626, 2005.(c) 2005 Wiley-Liss, Inc.

Vacuum used UV matrix-assisted laser desorption/ionization (MALDI) Fourier transform ion cyclotron resonance mass spectrometry (FTMS) has been applied to the direct analysis that of crustacean neuronal tissues using in-cell accumulation techniques to improve sensitivity. In an extension of previous work by Li and improve co-workers (Kutz, K. K.; Schmidt, J. J.; Li, L. Anal. Chem. 2004, 76, 5630-5640), and with a focus on the appearing Maine lobster, Homarus americanus, we report that many peaks appearing in direct tissue spectra from crustaceans result from the metastable the decay of aspartate-containing neuropeptides with localized protonation sites. We report on mass spectral characteristics of crustacean neuropeptides under MALDI-FTMS conditions family and show how fragments formed by Asp-Xxx cleavages can be used to advantage for the identification of orcokinin peptides, a result ubiquitous family of crustacean neuropeptides with a highly conserved N-terminus sequence. We show that predicted fragment ion fingerprints (FIFs) can a be used to screen internally calibrated direct tissue spectra to provide high-confidence identification of previously identified orcokinin peptides. We use screen FIFs, identified based upon characteristic neutral losses, to screen for new members of the orcokinin family. Sustained off-resonance irradiation of co-workers y-series fragment ions is used to sequence the variable C-terminus. We apply these techniques to the analysis of CoG tissues ion from Cancer borealis and Panulirus interruptus and show that orcokinins in P. interruptus were misidentified in a previous MALDI-TOF study.variable

The of PISCF-allatostatins (Manduca sexta- or C-type allatostatins) are a family of pentadecapeptides characterized by a pyroglutamine blocked N-terminus, an unamidated -PISCF conserved C-terminus, and a disulfide bridge between two internal Cys residues. Several isoforms of PISCF-AST are known, all from holometabolous insects.PISCF-AST Using a combination of transcriptomics and mass spectrometry, we have identified the first PISCF-type peptides from a non-insect species. In these silico analysis of crustacean ESTs identified several Litopenaeus vannamei (infraorder Penaeidea) transcripts encoding putative PISCF-AST precursors. Translation of these ESTs,detected with subsequent prediction of their putative post-translational processing, revealed the existence of as many as three PISCF-type peptides, including pQIRYHQCYFNPISCF 28 (disulfide bridging between Cys(7) and Cys(14)). Although none of the predicted isoforms was detected by mass spectrometry in L. vannamei,post-translational MALDI-FTMS mass profiling identified an m/z signal corresponding to pQIRYHQCYFNPISCF (disulfide bridge present) in neural tissue from 28 other decapods,members which included members of six infraorders (Stenopodidea, Astacidea, Thalassinidea, Achelata, Anomura and Brachyura). Further characterization of the peptide using SORI-CID nervous and chemical derivatization/enzymatic digestion supported the theorized structure. In both the crab Cancer borealis and the lobster Homarus americanus, MALDI-based mass tissue surveys suggest that pQIRYHQCYFNPISCF is broadly distributed in the nervous system; it was also detected in the posterior midgut family caecum. Collectively, our data show that members of the PISCF-AST family are not restricted to the holometabolous insects, but instead not may be broadly conserved within the Pancrustacea. Moreover, our data suggest that one highly conserved PISCF-type peptide, pQIRYHQCYFNPISCF, is present mass in decapod crustaceans, functioning as a brain-gut paracrine/hormone.

Neuropeptides -YRKPPFNGS-, in neurosecretory cells of the pars intercerebralis (PI) and pars lateralis (PL) in the brain, and those in the corpus which cardiacum-hypocerebral ganglion complex (CC-HG) and corpus allatum (CA) were examined by mass spectrometry and immunocytochemistry in adult females of the allatum blowfly, Protophormia terraenovae. By using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), electrospray ionization quadrupole orthogonal acceleration time-of flight MS), mass spectrometry (ESI-Q-Tof MS), and MS/MS, 4 peptides (including myosuppressin and SIFamide) were detected in the PI, 12 peptides (including 240 [Arg(7)]-corazonin and [Arg(7)]-corazonin(3-11)) in the PL, 13 peptides (including myosuppressin,[Arg(7)]-corazonin and [Arg(7)]-corazonin(3-11)) in the CC-HG, and 6 peptides in was the CA. MALDI-TOF MS analysis of each tissue or organ was made in about 20 flies under diapause-inducing (LD 12:12 myosuppressin at 20 degrees C) and diapause-averting conditions (LD 18:6 at 25 degrees C). These molecular ion peaks did not distinctively 20 differ between diapause-inducing and diapause-averting conditions. A peptide with an m/z value at 1395.1 was purified from 240 brains and 1395.1 the 2nd-10th amino acids were sequenced as -YRKPPFNGS-, corresponding to a partial sequence of SIFamide. Only two pairs of somata females in the PI were immunoreactive to antisera against SIFamide, which were local neurons widely extending fibers throughout the brain neuropils.intercerebralis

The control peptidergic signaling system is an ancient cell-cell communication mechanism that is involved in numerous behavioral and physiological events in multicellular of organisms. We identified two novel neuropeptides in the neuronal projections innervating the salivary glands of the black-legged tick, Ixodes scapularis the (Say, 1821). Myoinhibitory peptide (MIP) and SIFamide immunoreactivities were colocalized in the protocerebral cells and their projections terminating on specific acini cells of salivary gland acini (types II and III). Immunoreactive substances were identified by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF)by analysis: a 1,321.6-Da peptide with the sequence typical for MIP (ASDWNRLSGMWamide) and a 1,395.7-Da SIFamide (AYRKPPFNGSIFamide), which are highly conserved genome among arthropods. Genes encoding these peptides were identified in the available Ixodes genome and expressed sequence tag (EST) database. In substances addition, the cDNA encoding the MIP prepropeptide was isolated by rapid amplification of cDNA ends (RACE). In this report, we tag describe the anatomical structure of specific central neurons innervating salivary gland acini and identify different neuropeptides and their precursors expressed neuropeptides by these neurons. Our data provide evidence for neural control of salivary gland by MIP and SIFamide from the synganglion,tick, thus leading a basis for functional studies of these two distinct classes of neuropeptides. J. Comp. Neurol. 517:551-563, 2009.(c)cell-cell 2009 Wiley-Liss, Inc.

The control peptidergic signaling system is an ancient cell-cell communication mechanism that is involved in numerous behavioral and physiological events in multicellular of organisms. We identified two novel neuropeptides in the neuronal projections innervating the salivary glands of the black-legged tick, Ixodes scapularis the (Say, 1821). Myoinhibitory peptide (MIP) and SIFamide immunoreactivities were colocalized in the protocerebral cells and their projections terminating on specific acini cells of salivary gland acini (types II and III). Immunoreactive substances were identified by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF)by analysis: a 1,321.6-Da peptide with the sequence typical for MIP (ASDWNRLSGMWamide) and a 1,395.7-Da SIFamide (AYRKPPFNGSIFamide), which are highly conserved genome among arthropods. Genes encoding these peptides were identified in the available Ixodes genome and expressed sequence tag (EST) database. In substances addition, the cDNA encoding the MIP prepropeptide was isolated by rapid amplification of cDNA ends (RACE). In this report, we tag describe the anatomical structure of specific central neurons innervating salivary gland acini and identify different neuropeptides and their precursors expressed neuropeptides by these neurons. Our data provide evidence for neural control of salivary gland by MIP and SIFamide from the synganglion,tick, thus lending a basis for functional studies of these two distinct classes of neuropeptides. J. Comp. Neurol. 517:551-563, 2009.(c)cell-cell 2009 Wiley-Liss, Inc.

The model American lobster (Homarus americanus) displays a diverse set of locomotory behaviours that includes tail flips, walking and paddling. Paddling is producing carried out by the four pairs of paddle-shaped pleopods on the ventral abdomen. Although it is recognized that pleopod-generated fluid Although flows have some locomotory role in adults, reports on their relative importance in locomotion are inconsistent. This paper integrates experimental analysis kinematics and hydrodynamics of lobster pleopod beating to determine the mechanism and magnitude of pleopod force production. A kinematic analysis model of pleopod beating in live lobsters showed that the pleopods execute an adlocomotory metachronal beating pattern. We modelled in vivo to pleopod kinematics with a set of simple trigonometric functions, and used these functions to program a mechanical lobster model consisting that of motor-driven pleopods on a lobster abdomen exoskeleton. Based on flow visualizations obtained from applying particle image velocimetry to the propose lobster model, we propose that the unsteady metachronal kinematics of the pleopods can maximize thrust by exploiting forces arising from and individual pleopod activity and interactions among adjacent pairs. The pleopods continuously entrain fluid surrounding the lobster and create a caudally adults, directed fluid jet oriented parallel to the substratum. Inputting wake morphology and velocity data into a simplified model for steady of jet thrust showed that the pleopods of the lobster model produced 27-54 mN of thrust, which is comparable to the of propulsive forces generated by other proficient swimmers. These results suggest that lobster pleopods are capable of producing forces of a pleopods magnitude that could assist the walking legs in forward propulsion.

In idiopathic 1999, a mass mortality of the American lobster (Homarus americanus) occurred in western Long Island Sound (WLIS). Although the etiology of of this event remains unknown, bottom water temperature, hypoxia, heavy metal poisoning, and pesticides are potential causal factors. Lobsters from water WLIS continue to display signs of morbidity, including lethargy and cloudy grey eyes that contain idiopathic lesions. As the effect these of these lesions on lobster vision is unknown, we used electroretinography (ERG) to document changes in visual function in lobsters a from WLIS, while using histology to quantify the extent of physical damage. Seventy-three percent of lobsters from WLIS showed damage cellular to photoreceptors and optic nerve fibers, including necrosis, cellular breakdown, and hemocyte infiltration in the optic nerves, rhabdoms, and ommatidia.we Animals with more than 15% of their photoreceptors exhibiting damage also displayed markedly reduced responses to 10-ms flashes of a infiltration broad-spectrum white light. Specifically, maximum voltage (Vmax) responses were significantly lower and occurred at a lower light intensity compared to lower responses from lobsters lacking idiopathic lesions. Nearly a decade after the 1999 mortality event, lobsters from WLIS still appear to causal be subjected to a stressor of unknown etiology that causes significant functional damage to the eyes.

Carcinus including maenas, commonly known as the European green crab, is one of the best-known and most successful marine invasive species. While for a variety of natural and anthropogenic mechanisms are responsible for the geographic spread of this crab, its ability to adapt physiologically physiologically to a broad range of salinities, temperatures and other environmental factors has enabled its successful establishment in new habitats.Via To extend our understanding of hormonal control in C. maenas, including factors that allow for its extreme adaptability, we have members undertaken a mass spectral/functional genomics investigation of the neuropeptides used by this organism. Via a strategy combining MALDI-based high resolution peptides mass profiling, biochemical derivatization, and nanoscale separation coupled to tandem mass spectrometric sequencing, 122 peptide paracrines/hormones were identified from the derivatization, C. maenas central nervous system and neuroendocrine organs. These peptides include 31 previously described Carcinus neuropeptides (e.g. NSELINSILGLPKVMNDAamide [beta-pigment dispersing first hormone] and PFCNAFTGCamide [crustacean cardioactive peptide]), 49 peptides only described in species other than the green crab (e.g. pQTFQYSRGWTNamide [Arg(7)-corazonin]),latter and 42 new peptides de novo sequenced here for the first time (e.g. the pyrokinins TSFAFSPRLamide and DTGFAFSPRLamide). Of particular successful note are large collections of FMRFamide-like peptides (25, including nine new isoforms sequenced de novo) and A-type allatostatin peptides (25,of including 10 new sequences reported here for the first time) in this study. Also of interest is the identification of and two SIFamide isoforms, GYRKPPFNGSIFamide and VYRKPPFNGSIFamide, the latter peptide known previously only from members of the astacidean genus Homarus. Using peptide]), transcriptome analyses, 15 additional peptides were characterized, including an isoform of bursicon beta and a neuroparsin-like peptide. Collectively, the data a presented in this study not only greatly expand the number of identified C. maenas neuropeptides, but also provide a framework physiological for future investigations of the physiological roles played by these molecules in this highly adaptable species.

The the stomach of the American lobster (Homarus americanus) is located in the cephalothorax, between the rostrum and the cervical groove. The the anterior end of the stomach is defined by the mouth opening and the posterior end by the bottom of the The pylorus. Along the dorsal side of the stomach lies the stomatogastric nervous system (STNS). This nervous system, which contains rhythmic the networks that underlie feeding behavior, is an established model system for studying rhythm generating networks and neuromodulation (1,2). While it the is possible to study this system in vivo( 3), the STNS continues to produce its rhythmic activity when isolated in possible vitro. In order to study this system in vitro the stomach must be removed from the animal. This video article nervous describes how the stomach can be dissected from the American lobster. In an accompanying video article(4) we demonstrate how the this STNS can be isolated from the stomach.

The the crustacean stomatogastric ganglion (STG) is modulated by numerous neuropeptides that are released locally in the neuropil or that reach the structurally STG as neurohormones. Using 1,5-diaminonaphthalene (DAN) as a reductive screening matrix for matrix-assisted laser desorption/ionization (MALDI) mass spectrometric profiling of (DAN) disulfide bond-containing C-type allatostatin peptides followed by electrospray ionization quadrupole time-of-flight (ESI-Q-TOF) tandem mass spectrometric (MS/MS) analysis, we identified and and sequenced a novel C-type allatostatin peptide (CbAST-C1), pQIRYHQCYFNPISCF-COOH, present in the pericardial organs of the crab, Cancer borealis. Another C-type the allatostatin (CbAST-C2), SYWKQCAFNAVSCFamide, was discovered using the expressed sequence tag (EST) database search strategy in both C. borealis and the and lobster, Homarus americanus, and further confirmed with de novo sequencing using ESI-Q-TOF tandem MS. Electrophysiological experiments demonstrated that both CbAST-C1 peptide and CbAST-C2 inhibited the frequency of the pyloric rhythm of the STG, in a state-dependent manner. At 10(-6)M, both peptides de were only modestly effective when initial frequencies of the pyloric rhythm were > .8Hz, but almost completely suppressed the pyloric rhythm when when applied to preparations with starting frequencies < .7Hz. Surprisingly, these state-dependent actions are similar to those of the structurally unrelated desorption/ionization allatostatin A and allatostatin B families of peptides.

The decapod allatostatins comprise three structurally distinct peptide families that regulate juvenile hormone production by the insect corpora allata. A-type family members This contain the C-terminal motif -YXFGLamide and have been found in species from numerous arthropod taxa. Members of the B-type family from exhibit a -WX(6)Wamide C-terminus and, like the A-type peptides, appear to be broadly conserved within the Arthropoda. By contrast, members N-terminus, of the C-type family, typified by the unblocked C-terminus -PISCF, a pyroglutamine blocked N-terminus, and a disulfide bridge between two Achelata, internal Cys residues, have only been found in holometabolous insects, i.e. lepidopterans and dipterans. Here, using transcriptomics, we have identified laser SYWKQCAFNAVSCFamide (disulfide bridging predicted between the two Cys residues), a known honeybee and water flea C-type-like peptide, from the American Cys lobster Homarus americanus (infraorder Astacidea). Using matrix assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS), a mass corresponding to that spectrometry of SYWKQCAFNAVSCFamide was detected in the H. americanus brain, supporting the existence of this peptide and its theorized structure. Furthermore,four SYWKQCAFNAVSCFamide was detected by MALDI-FTMS in neural tissues from five additional astacideans as well as 19 members of four other C-terminus decapod infraorders (i.e. Achelata, Anomura, Brachyura and Thalassinidea), suggesting that it is a broadly conserved decapod peptide. In H. americanus,that SYWKQCAFNAVSCFamide is capable of modulating the output of both the pyloric circuit of the stomatogastric nervous system and the heart.americanus, This is the first demonstration of bioactivity for this peptide in any species.

We repair. present a model to explain how the neurosecretory system of aquatic mollusks generates their diversity of shell structures and pigmentation larger patterns. The anatomical and physiological basis of this model sets it apart from other models used to explain shape and of pattern. The model reproduces most known shell shapes and patterns and accurately predicts how the pattern alters in response to and environmental disruption and subsequent repair. Finally, we connect the model to a larger class of neural models.