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Patrick Flammang - One of the best experts on this subject based on the ideXlab platform.
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The structural and chemical basis of temporary adhesion in the sea star Asterina gibbosa
Beilstein-Institut, 2018Co-Authors: Birgit Lengerer, Elise Hennebert, Marie Bonneel, Mathilde Lefevre, Philippe Leclère, Emmanuel Gosselin, Peter Ladurner, Patrick FlammangAbstract:Background: Marine biological adhesives are a promising source of inspiration for biomedical and industrial applications. Nevertheless, natural adhesives and especially temporary adhesion systems are mostly unexplored. Sea stars are able to repeatedly attach and detach their hydraulic Tube Feet. This ability is based on a duo-gland system and, upon detachment, the adhesive material stays behind on the substrate as a 'footprint'. In recent years, characterization of sea star temporary adhesion has been focussed on the forcipulatid species Asterias rubens.Results: We investigated the temporary adhesion system in the distantly related valvatid species Asterina gibbosa. The morphology of Tube Feet was described using histological sections, transmission-, and scanning electron microscopy. Ultrastructural investigations revealed two adhesive gland cell types that both form electron-dense secretory granules with a more lucid outer rim and one de-adhesive gland cell type with homogenous granules. The footprints comprised a meshwork on top of a thin layer. This topography was consistently observed using various methods like scanning electron microscopy, 3D confocal interference microscopy, atomic force microscopy, and light microscopy with crystal violet staining. Additionally, we tested 24 commercially available lectins and two antibodies for their ability to label the adhesive epidermis and footprints. Out of 15 lectins labelling structures in the area of the duo-gland adhesive system, only one also labelled footprints indicating the presence of glycoconjugates with α-linked mannose in the secreted material.Conclusion: Despite the distant relationship between the two sea star species, the morphology of Tube Feet and topography of footprints in A. gibbosa shared many features with the previously described findings in A. rubens. These similarities might be due to the adaptation to a benthic life on rocky intertidal areas. Lectin- and immuno-labelling indicated similarities but also some differences in adhesive composition between the two species. Further research on the temporary adhesive of A. gibbosa will allow the identification of conserved motifs in sea star adhesion and might facilitate the development of biomimetic, reversible glues
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High opsin diversity in a non-visual infaunal brittle star
BMC genomics, 2014Co-Authors: Jérôme Delroisse, Sam Dupont, Jérôme Mallefet, Esther Ullrich-lüter, Olga Ortega-martinez, Patrick FlammangAbstract:Background: In metazoans, opsins are photosensitive proteins involved in both vision and non-visual photoreception. Echinoderms have no well-defined eyes but several opsin genes were found in the purple sea urchin (Strongylocentrotus purpuratus) genome. Molecular data are lacking for other echinoderm classes although many species are known to be light sensitive. Results: In this study focused on the European brittle star Amphiura filiformis, we first highlighted a blue-green light sensitivity using a behavioural approach. We then identified 13 new putative opsin genes against eight bona fide opsin genes in the genome of S. purpuratus. Six opsins were included in the rhabdomeric opsin group (r-opsins). In addition, one putative ciliary opsin (c-opsin), showing high similarity with the c-opsin of S. purpuratus (Sp-opsin 1), one Go opsin similar to Sp-opsins 3.1 and 3.2, two basal-branch opsins similar to Sp-opsins 2 and 5, and two neuropsins similar to Sp-opsin 8, were identified. Finally, two sequences from one putative RGR opsin similar to Sp-opsin 7 were also detected. Adult arm transcriptome analysis pinpointed opsin mRNAs corresponding to one r-opsin, one neuropsin and the homologue of Sp-opsin 2. Opsin phylogeny was determined by maximum likelihood and Bayesian analyses. Using antibodies designed against c- and r-opsins from S. purpuratus, we detected putative photoreceptor cells mainly in spines and Tube Feet of A. filiformis, respectively. The r-opsin expression pattern is similar to the one reported in S. purpuratus with cells labelled at the tip and at the base of the Tube Feet. In addition, r-opsin positive cells were also identified in the radial nerve of the arm. C-opsins positive cells, expressed in pedicellariae, spines, Tube Feet and epidermis in S. purpuratus were observed at the level of the spine stroma in the brittle star. Conclusion: Light perception in A. filiformis seems to be mediated by opsins (c- and r-) in, at least, spines, Tube Feet and in the radial nerve cord. Other non-visual opsin types could participate to the light perception process indicating a complex expression pattern of opsins in this infaunal brittle star.
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effects of co2 induced ocean acidification on physiological and mechanical properties of the starfish asterias rubens
Journal of Experimental Marine Biology and Ecology, 2013Co-Authors: Patrick Flammang, Marie Collard, Ana Isabel Catarino, Stephanie Bonnet, Philippe DuboisAbstract:Abstract The increase in atmospheric CO2 due to anthropogenic activity results in an acidification of the surface waters of the oceans. Its impact will depend on the considered organisms and ecosystems. The intertidal may harbor organisms pre-adapted to the upcoming changes as they face tidal pH and temperature fluctuations. However, these environments will be more affected as shallow waters will face the highest decrease in seawater pH. In this context, the effects of reduced environmental pH on the physiology and Tube Feet mechanical properties of the intertidal starfish Asterias rubens, a top predator, were investigated during 15 and 27 days. A. rubens showed a respiratory acidosis with its coelomic fluid pH always lower than that of seawater. This acidosis was most pronounced at pH 7.4. Notwithstanding, the starfish showed no significant variations in RNA/DNA ratio of different tissues and in Tube Feet strength. However, respiration rates were significantly lower for individuals maintained at reduced seawater pH. Within the ocean acidification context, the present results suggest that A. rubens withstands the effects of reduced seawater pH, at least for medium term exposures.
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Characterization of the protein fraction of the temporary adhesive secreted by the Tube Feet of the sea star Asterias rubens.
Biofouling, 2012Co-Authors: Elise Hennebert, Ruddy Wattiez, J. Herbert Waite, Patrick FlammangAbstract:Sea stars are able to make firm but temporary attachments to various substrata by secretions released by their Tube Feet. After Tube foot detachment, the adhesive secretions remain on the substratum as a footprint. Proteins presumably play a key role in sea star adhesion, as evidenced by the removal of footprints from surfaces after a treatment with trypsin. However, until now, characterisation was hampered by their high insolubility. In this study, a non-hydrolytic method was used to render most of the proteins constituting the adhesive footprints soluble. After analysis by SDS-PAGE, the proteins separated into about 25 bands, which ranged from 25 to 450 kDa in apparent molecular weight. Using mass spectrometry and a homology-database search, it was shown that several of the proteins are known intracellular proteins, presumably resulting from contamination of footprint material with Tube foot epidermal cells. However, 11 protein bands, comprising the most abundant proteins, were not identified and might ...
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characterisation of the carbohydrate fraction of the temporary adhesive secreted by the Tube Feet of the sea star asterias rubens
Marine Biotechnology, 2011Co-Authors: Elise Hennebert, Ruddy Wattiez, Patrick FlammangAbstract:In sea stars, adhesion takes place at the level of a multitude of small appendages, the Tube Feet. It involves the secretion of an adhesive material which, after Tube foot detachment, remains on the substratum as a footprint. It was previously reported that the two main organic components of this material are proteins and carbohydrates. The carbohydrate moiety of the adhesive secretion of Asterias rubens was investigated using a set of 16 lectins which were used on sections through Tube Feet, on footprints, and on the proteins extracted from these footprints. After gel electrophoresis, these proteins separate into eight protein bands which were named sea star footprint proteins (Sfps). Eleven lectins label the Tube foot epidermis at the level of the adhesive cells, four react with footprints, and eight with two of the extracted footprint proteins, which are therefore classified as glycoproteins. Sfp-290 appears to bear mostly N-linked oligosaccharides and Sfp-210 principally O-linked oligosaccharides. The outer chains of both glycoproteins enclose galactose, N-acetylgalactosamine, fucose, and sialic acid residues. Another part of the carbohydrate fraction of the footprints would be in the form of larger molecules, such as sialylated proteoglycans. These two types of glycoconjugates are presumably key components of the sea star temporary adhesive providing both cohesive and adhesive contributions through electrostatic interactions by the polar and hydrogen-bonding functional groups of their glycan chains.
Maurice R Elphick - One of the best experts on this subject based on the ideXlab platform.
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functional characterization of a second pedal peptide orcokinin type neuropeptide signaling system in the starfish asterias rubens
The Journal of Comparative Neurology, 2018Co-Authors: Ming Lin, Michaela Egertova, Cleidiane G Zampronio, Alexandra M E Jones, Maurice R ElphickAbstract:Molluscan pedal peptides (PPs) and arthropod orcokinins (OKs) are prototypes of a family of neuropeptides that have been identified in several phyla. Recently, starfish myorelaxant peptide (SMP) was identified as a PP/OK-type neuropeptide in the starfish Patiria pectinifera (phylum Echinodermata). Furthermore, analysis of transcriptome sequence data from the starfish Asterias rubens revealed two PP/OK-type precursors: an SMP-type precursor (A. rubens PP-like neuropeptide precursor 1; ArPPLNP1) and a second precursor (ArPPLNP2). We reported previously a detailed analysis of ArPPLNP1 expression in A. rubens and here we report the first functional characterization ArPPLNP2-derived neuropeptides. Sequencing of a cDNA encoding ArPPLNP2 revealed that it comprises eleven related neuropeptides (ArPPLN2a-k), the structures of several of which were confirmed using mass spectrometry. Analysis of the expression of ArPPLNP2 and neuropeptides derived from this precursor using mRNA in situ hybridization and immunohistochemistry revealed a widespread distribution, including expression in radial nerve cords, circumoral nerve ring, digestive system, Tube Feet and innervation of interossicular muscles. In vitro pharmacology revealed that the ArPPLNP2-derived neuropeptide ArPPLN2h has no effect on the contractility of Tube Feet or the body wall-associated apical muscle, contrasting with the relaxing effect of ArPPLN1b (ArSMP) on these preparations. ArPPLN2h does, however, cause dose-dependent relaxation of cardiac stomach preparations, with greater potency/efficacy than ArPPLN1b and with similar potency/efficacy to the SALMFamide neuropeptide S2. In conclusion, there are similarities in the expression patterns of ArPPLNP1 and ArPPLNP2 but our data also indicate specialization in the roles of neuropeptides derived from these two PP/OK-type precursors in starfish.
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Data_Sheet_1_Biochemical, Anatomical, and Pharmacological Characterization of Calcitonin-Type Neuropeptides in Starfish: Discovery of an Ancient Role as Muscle Relaxants.DOCX
2018Co-Authors: Weigang Cai, Michaela Egertova, Cleidiane G Zampronio, Alexandra M E Jones, Chan-hee Kim, Nam Gyu Park, Maurice R ElphickAbstract:Calcitonin (CT) is a peptide hormone released by the thyroid gland that regulates blood Ca2+ levels in mammals. The CT gene is alternatively spliced, with one transcript encoding CT and another transcript encoding the CT-like neuropeptide calcitonin-gene related peptide (α-CGRP), which is a powerful vasodilator. Other CT-related peptides in vertebrates include adrenomedullin, amylin, and intermedin, which also act as smooth muscle relaxants. The evolutionary origin of CT-type peptides has been traced to the bilaterian common ancestor of protostomes and deuterostomes and a CT-like peptide (DH31) has been identified as a diuretic hormone in some insect species. However, little is known about the physiological roles of CT-type peptides in other invertebrates. Here we characterized a CT-type neuropeptide in a deuterostomian invertebrate—the starfish Asterias rubens (Phylum Echinodermata). A CT-type precursor cDNA (ArCTP) was sequenced and the predicted structure of the peptide (ArCT) derived from ArCTP was confirmed using mass spectrometry. The distribution of ArCTP mRNA and the ArCT peptide was investigated using in situ hybridization and immunohistochemistry, respectively, revealing stained cells/processes in the nervous system, digestive system, and muscular organs, including the apical muscle and Tube Feet. Investigation of the effects of synthetic ArCT on in vitro preparations of the apical muscle and Tube Feet revealed that it acts as a relaxant, causing dose-dependent reversal of acetylcholine-induced contraction. Furthermore, a muscle relaxant present in whole-animal extracts of another starfish species, Patiria pectinifera, was identified as an ortholog of ArCT and named PpCT. Consistent with the expression pattern of ArCTP in A. rubens, RT-qPCR revealed that in P. pectinifera the PpCT precursor transcript is more abundant in the radial nerve cords than in other tissues/organs analyzed. In conclusion, our findings indicate that the physiological action of CT-related peptides as muscle relaxants in vertebrates may reflect an evolutionarily ancient role of CT-type neuropeptides that can be traced back to the common ancestor of deuterostomes.
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Table_1_Characterization of NGFFYamide Signaling in Starfish Reveals Roles in Regulation of Feeding Behavior and Locomotory Systems.XLSX
2018Co-Authors: Ana B. Tinoco, Michaela Egertova, Dean C. Semmens, Emma C. Patching, Elizabeth F. Gunner, Maurice R ElphickAbstract:Neuropeptides in deuterostomian invertebrates that have an Asn-Gly motif (NG peptides) have been identified as orthologs of vertebrate neuropeptide-S (NPS)-type peptides and protostomian crustacean cardioactive peptide (CCAP)-type neuropeptides. To obtain new insights into the physiological roles of NG peptides in deuterostomian invertebrates, here we have characterized the NG peptide signaling system in an echinoderm—the starfish Asterias rubens. The neuropeptide NGFFYamide was identified as the ligand for an A. rubens NPS/CCAP-type receptor, providing further confirmation that NG peptides are orthologs of NPS/CCAP-type neuropeptides. Using mRNA in situ hybridization, cells expressing the NGFFYamide precursor transcript were revealed in the radial nerve cords, circumoral nerve ring, coelomic epithelium, apical muscle, body wall, stomach, and Tube Feet of A. rubens, indicating that NGFFYamide may have a variety of physiological roles in starfish. One of the most remarkable aspects of starfish biology is their feeding behavior, where the stomach is everted out of the mouth over the soft tissue of prey. Previously, we reported that NGFFYamide triggers retraction of the everted stomach in A. rubens and here we show that in vivo injection of NGFFYamide causes a significant delay in the onset of feeding on prey. To investigate roles in regulating other aspects of starfish physiology, we examined the in vitro effects of NGFFYamide and found that it causes relaxation of acetylcholine-contracted apical muscle preparations and induction of tonic and phasic contraction of Tube Feet. Furthermore, analysis of the effects of in vivo injection of NGFFYamide on starfish locomotor activity revealed that it causes a significant reduction in mean velocity and distance traveled. Interestingly, experimental studies on mammals have revealed that NPS is an anxiolytic that suppresses appetite and induces hyperactivity in mammals. Our characterization of the actions of NGFFYamide in starfish indicates that NPS/NG peptide/CCAP-type signaling is an evolutionarily ancient regulator of feeding and locomotion.
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Characterization of NGFFYamide Signaling in Starfish Reveals Roles in Regulation of Feeding Behavior and Locomotory Systems
Frontiers Media S.A., 2018Co-Authors: Ana B. Tinoco, Michaela Egertova, Dean C. Semmens, Emma C. Patching, Elizabeth F. Gunner, Maurice R ElphickAbstract:Neuropeptides in deuterostomian invertebrates that have an Asn-Gly motif (NG peptides) have been identified as orthologs of vertebrate neuropeptide-S (NPS)-type peptides and protostomian crustacean cardioactive peptide (CCAP)-type neuropeptides. To obtain new insights into the physiological roles of NG peptides in deuterostomian invertebrates, here we have characterized the NG peptide signaling system in an echinoderm—the starfish Asterias rubens. The neuropeptide NGFFYamide was identified as the ligand for an A. rubens NPS/CCAP-type receptor, providing further confirmation that NG peptides are orthologs of NPS/CCAP-type neuropeptides. Using mRNA in situ hybridization, cells expressing the NGFFYamide precursor transcript were revealed in the radial nerve cords, circumoral nerve ring, coelomic epithelium, apical muscle, body wall, stomach, and Tube Feet of A. rubens, indicating that NGFFYamide may have a variety of physiological roles in starfish. One of the most remarkable aspects of starfish biology is their feeding behavior, where the stomach is everted out of the mouth over the soft tissue of prey. Previously, we reported that NGFFYamide triggers retraction of the everted stomach in A. rubens and here we show that in vivo injection of NGFFYamide causes a significant delay in the onset of feeding on prey. To investigate roles in regulating other aspects of starfish physiology, we examined the in vitro effects of NGFFYamide and found that it causes relaxation of acetylcholine-contracted apical muscle preparations and induction of tonic and phasic contraction of Tube Feet. Furthermore, analysis of the effects of in vivo injection of NGFFYamide on starfish locomotor activity revealed that it causes a significant reduction in mean velocity and distance traveled. Interestingly, experimental studies on mammals have revealed that NPS is an anxiolytic that suppresses appetite and induces hyperactivity in mammals. Our characterization of the actions of NGFFYamide in starfish indicates that NPS/NG peptide/CCAP-type signaling is an evolutionarily ancient regulator of feeding and locomotion
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a genomic view of the sea urchin nervous system
Developmental Biology, 2006Co-Authors: Robert D Burke, Maurice R Elphick, Lynne M Angerer, Glen Humphrey, Shunsuke Yaguchi, Takae Kiyama, Shuguang Liang, Xiuqian Mu, C Agca, William H KleinAbstract:The sequencing of the Strongylocentrotus purpuratus genome provides a unique opportunity to investigate the function and evolution of neural genes. The neurobiology of sea urchins is of particular interest because they have a close phylogenetic relationship with chordates, yet a distinctive pentaradiate body plan and unusual neural organization. Orthologues of transcription factors that regulate neurogenesis in other animals have been identified and several are expressed in neurogenic domains before gastrulation indicating that they may operate near the top of a conserved neural gene regulatory network. A family of genes encoding voltage-gated ion channels is present but, surprisingly, genes encoding gap junction proteins (connexins and pannexins) appear to be absent. Genes required for synapse formation and function have been identified and genes for synthesis and transport of neurotransmitters are present. There is a large family of G-protein-coupled receptors, including 874 rhodopsin-type receptors, 28 metabotropic glutamate-like receptors and a remarkably expanded group of 161 secretin receptor-like proteins. Absence of cannabinoid, lysophospholipid and melanocortin receptors indicates that this group may be unique to chordates. There are at least 37 putative G-protein-coupled peptide receptors and precursors for several neuropeptides and peptide hormones have been identified, including SALMFamides, NGFFFamide, a vasotocin-like peptide, glycoprotein hormones and insulin/insulin-like growth factors. Identification of a neurotrophin-like gene and Trk receptor in sea urchin indicates that this neural signaling system is not unique to chordates. Several hundred chemoreceptor genes have been predicted using several approaches, a number similar to that for other animals. Intriguingly, genes encoding homologues of rhodopsin, Pax6 and several other key mammalian retinal transcription factors are expressed in Tube Feet, suggesting Tube Feet function as photosensory organs. Analysis of the sea urchin genome presents a unique perspective on the evolutionary history of deuterostome nervous systems and reveals new approaches to investigate the development and neurobiology of sea urchins.
Maria I Arnone - One of the best experts on this subject based on the ideXlab platform.
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unique system of photoreceptors in sea urchin Tube Feet
Proceedings of the National Academy of Sciences of the United States of America, 2011Co-Authors: Esther Ullrichluter, Enrique Arboleda, Harald Zur Hausen, Sam Dupont, Maria I ArnoneAbstract:Different sea urchin species show a vast variety of responses to variations in light intensity; however, despite this behavioral evidence for photosensitivity, light sensing in these animals has remained an enigma. Genome information of the recently sequenced purple sea urchin (Strongylocentrotus purpuratus) allowed us to address this question from a previously unexplored molecular perspective by localizing expression of the rhabdomeric opsin Sp-opsin4 and Sp-pax6, two genes essential for photoreceptor function and development, respectively. Using a specifically designed antibody against Sp-Opsin4 and in situ hybridization for both genes, we detected expression in two distinct groups of photoreceptor cells (PRCs) located in the animal's numerous Tube Feet. Specific reactivity of the Sp-Opsin4 antibody with sea star optic cushions, which regulate phototaxis, suggests a similar visual function in sea urchins. Ultrastructural characterization of the sea urchin PRCs revealed them to be of a microvillar receptor type. Our data suggest that echinoderms, in contrast to chordates, deploy a microvillar, r-opsin–expressing PRC type for vision, a feature that has been so far documented only in protostome animals. Surprisingly, sea urchin PRCs lack any associated screening pigment. Indeed, one of the Tube foot PRC clusters may account for directional vision by being shaded through the opaque calcite skeleton. The PRC axons connect to the animal internal nervous system, suggesting an integrative function beyond local short circuits. Because juveniles display no phototaxis until skeleton completion, we suggest a model in which the entire sea urchin, deploying its skeleton as PRC screening device, functions as a huge compound eye.
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opsins and clusters of sensory g protein coupled receptors in the sea urchin genome
Developmental Biology, 2006Co-Authors: Florian Raible, Tobias Kaller, Detlev Arendt, Kristin Tessmarraible, Enrique Arboleda, Peer Bork, Maria I ArnoneAbstract:Rhodopsin-type G-protein-coupled receptors (GPCRs) contribute the majority of sensory receptors in vertebrates. With 979 members, they form the largest GPCR family in the sequenced sea urchin genome, constituting more than 3% of all predicted genes. The sea urchin genome encodes at least six Opsin proteins. Of these, one rhabdomeric, one ciliary and two Go-type Opsins can be assigned to ancient bilaterian Opsin subfamilies. Moreover, we identified four greatly expanded subfamilies of rhodopsin-type GPCRs that we call sea urchin specific rapidly expanded lineages of GPCRs (surreal-GPCRs). Our analysis of two of these groups revealed genomic clustering and single-exon gene structures similar to the most expanded group of vertebrate rhodopsin-type GPCRs, the olfactory receptors. We hypothesize that these genes arose by rapid duplication in the echinoid lineage and act as chemosensory receptors of the animal. In support of this, group B surreal-GPCRs are most prominently expressed in distinct classes of pedicellariae and Tube Feet of the adult sea urchin, structures that have previously been shown to react to chemical stimuli and to harbor sensory neurons in echinoderms. Notably, these structures also express different opsins, indicating that sea urchins possess an intricate molecular set-up to sense their environment.
Elise Hennebert - One of the best experts on this subject based on the ideXlab platform.
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The structural and chemical basis of temporary adhesion in the sea star Asterina gibbosa
Beilstein-Institut, 2018Co-Authors: Birgit Lengerer, Elise Hennebert, Marie Bonneel, Mathilde Lefevre, Philippe Leclère, Emmanuel Gosselin, Peter Ladurner, Patrick FlammangAbstract:Background: Marine biological adhesives are a promising source of inspiration for biomedical and industrial applications. Nevertheless, natural adhesives and especially temporary adhesion systems are mostly unexplored. Sea stars are able to repeatedly attach and detach their hydraulic Tube Feet. This ability is based on a duo-gland system and, upon detachment, the adhesive material stays behind on the substrate as a 'footprint'. In recent years, characterization of sea star temporary adhesion has been focussed on the forcipulatid species Asterias rubens.Results: We investigated the temporary adhesion system in the distantly related valvatid species Asterina gibbosa. The morphology of Tube Feet was described using histological sections, transmission-, and scanning electron microscopy. Ultrastructural investigations revealed two adhesive gland cell types that both form electron-dense secretory granules with a more lucid outer rim and one de-adhesive gland cell type with homogenous granules. The footprints comprised a meshwork on top of a thin layer. This topography was consistently observed using various methods like scanning electron microscopy, 3D confocal interference microscopy, atomic force microscopy, and light microscopy with crystal violet staining. Additionally, we tested 24 commercially available lectins and two antibodies for their ability to label the adhesive epidermis and footprints. Out of 15 lectins labelling structures in the area of the duo-gland adhesive system, only one also labelled footprints indicating the presence of glycoconjugates with α-linked mannose in the secreted material.Conclusion: Despite the distant relationship between the two sea star species, the morphology of Tube Feet and topography of footprints in A. gibbosa shared many features with the previously described findings in A. rubens. These similarities might be due to the adaptation to a benthic life on rocky intertidal areas. Lectin- and immuno-labelling indicated similarities but also some differences in adhesive composition between the two species. Further research on the temporary adhesive of A. gibbosa will allow the identification of conserved motifs in sea star adhesion and might facilitate the development of biomimetic, reversible glues
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Characterization of the protein fraction of the temporary adhesive secreted by the Tube Feet of the sea star Asterias rubens.
Biofouling, 2012Co-Authors: Elise Hennebert, Ruddy Wattiez, J. Herbert Waite, Patrick FlammangAbstract:Sea stars are able to make firm but temporary attachments to various substrata by secretions released by their Tube Feet. After Tube foot detachment, the adhesive secretions remain on the substratum as a footprint. Proteins presumably play a key role in sea star adhesion, as evidenced by the removal of footprints from surfaces after a treatment with trypsin. However, until now, characterisation was hampered by their high insolubility. In this study, a non-hydrolytic method was used to render most of the proteins constituting the adhesive footprints soluble. After analysis by SDS-PAGE, the proteins separated into about 25 bands, which ranged from 25 to 450 kDa in apparent molecular weight. Using mass spectrometry and a homology-database search, it was shown that several of the proteins are known intracellular proteins, presumably resulting from contamination of footprint material with Tube foot epidermal cells. However, 11 protein bands, comprising the most abundant proteins, were not identified and might ...
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characterisation of the carbohydrate fraction of the temporary adhesive secreted by the Tube Feet of the sea star asterias rubens
Marine Biotechnology, 2011Co-Authors: Elise Hennebert, Ruddy Wattiez, Patrick FlammangAbstract:In sea stars, adhesion takes place at the level of a multitude of small appendages, the Tube Feet. It involves the secretion of an adhesive material which, after Tube foot detachment, remains on the substratum as a footprint. It was previously reported that the two main organic components of this material are proteins and carbohydrates. The carbohydrate moiety of the adhesive secretion of Asterias rubens was investigated using a set of 16 lectins which were used on sections through Tube Feet, on footprints, and on the proteins extracted from these footprints. After gel electrophoresis, these proteins separate into eight protein bands which were named sea star footprint proteins (Sfps). Eleven lectins label the Tube foot epidermis at the level of the adhesive cells, four react with footprints, and eight with two of the extracted footprint proteins, which are therefore classified as glycoproteins. Sfp-290 appears to bear mostly N-linked oligosaccharides and Sfp-210 principally O-linked oligosaccharides. The outer chains of both glycoproteins enclose galactose, N-acetylgalactosamine, fucose, and sialic acid residues. Another part of the carbohydrate fraction of the footprints would be in the form of larger molecules, such as sialylated proteoglycans. These two types of glycoconjugates are presumably key components of the sea star temporary adhesive providing both cohesive and adhesive contributions through electrostatic interactions by the polar and hydrogen-bonding functional groups of their glycan chains.
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micro and nanostructure of the adhesive material secreted by the Tube Feet of the sea star asterias rubens
Journal of Structural Biology, 2008Co-Authors: Elise Hennebert, Pascal Viville, Roberto Lazzaroni, Patrick FlammangAbstract:To attach to underwater surfaces, sea stars rely on adhesive secretions produced by specialised organs, the Tube Feet. Adhesion is temporary and Tube Feet can also voluntarily become detached. The adhesive material is produced by two types of adhesive secretory cells located in the epidermis of the Tube foot disc, and is deposited between the disc surface and the substratum. After detachment, this material remains on the substratum as a footprint. Using LM, SEM, and AFM, we described the fine structure of footprints deposited on various substrata by individuals of Asterias rubens. Ultrastructure of the adhesive layer of attached Tube Feet was also investigated using TEM. Whatever the method used, the adhesive material appeared as made up of globular nanostructures forming a meshwork deposited on a thin homogeneous film. This appearance did not differ according to whether the footprints were fixed or not, and whether they were observed hydrated or dry. TEM observations suggest that type 2 adhesive cells would be responsible for the release of the material constituting the homogeneous film whereas type 1 adhesive cells would produce the material forming the meshwork. This reticulated pattern would originate from the arrangement of the adhesive cell secretory pores on the disc surface.
Derek J Siveter - One of the best experts on this subject based on the ideXlab platform.
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an edrioasteroid from the silurian herefordshire lagerstatte of england reveals the nature of the water vascular system in an extinct echinoderm
Proceedings of The Royal Society B: Biological Sciences, 2017Co-Authors: Derek E G Briggs, Derek J Siveter, Mark D Sutton, Imran A RahmanAbstract:Echinoderms are unique in having a water vascular system with Tube Feet, which perform a variety of functions in living forms. Here, we report the first example of preserved Tube Feet in an extinct group of echinoderms. The material, from the Silurian Herefordshire Lagerstatte, UK, is assigned to a new genus and species of rhenopyrgid edrioasteroid, Heropyrgus disterminus . The Tube Feet attach to the inner surface of compound interradial plates and form two sets, an upper and a lower, an arrangement never reported previously in an extant or extinct echinoderm. Cover plates are absent and floor plates are separated creating a large permanent entrance to the interior of the oral area. The Tube Feet may have captured food particles that entered the oral area and/or enhanced respiration. The pentameral symmetry of the oral surface transitions to eight columns in which the plates are vertically offset resulting in a spiral appearance. This change in symmetry may reflect flexibility in the evolutionary development of the axial and extraxial zones in early echinoderm evolution.
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an edrioasteroid from the silurian herefordshire lagerstatte of england reveals the nature of the water vascular system in an extinct echinoderm
Proceedings of The Royal Society B: Biological Sciences, 2017Co-Authors: Derek E G Briggs, Derek J Siveter, Mark D Sutton, Imran A RahmanAbstract:Echinoderms are unique in having a water vascular system with Tube Feet, which perform a variety of functions in living forms. Here, we report the first example of preserved Tube Feet in an extinct group of echinoderms. The material, from the Silurian Herefordshire Lagerstatte, UK, is assigned to a new genus and species of rhenopyrgid edrioasteroid, Heropyrgus disterminus . The Tube Feet attach to the inner surface of compound interradial plates and form two sets, an upper and a lower, an arrangement never reported previously in an extant or extinct echinoderm. Cover plates are absent and floor plates are separated creating a large permanent entrance to the interior of the oral area. The Tube Feet may have captured food particles that entered the oral area and/or enhanced respiration. The pentameral symmetry of the oral surface transitions to eight columns in which the plates are vertically offset resulting in a spiral appearance. This change in symmetry may reflect flexibility in the evolutionary development of the axial and extraxial zones in early echinoderm evolution.
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An edrioasteroid from the Silurian Herefordshire Lagerstätte of England reveals the nature of the water vascular system in an extinct echinoderm
'The Royal Society', 2017Co-Authors: Briggs Deg, Derek J Siveter, Ia RahmanAbstract:Echinoderms are unique in having a water vascular system with Tube Feet, which perform a variety of functions in living forms. Here, we report the first example of preserved Tube Feet in an extinct group of echinoderms. The material, from the Silurian Herefordshire Lagerstätte, UK, is assigned to a new genus and species of rhenopyrgid edrioasteroid, Heropyrgus disterminus. The Tube Feet attach to the inner surface of compound interradial plates and form two sets, an upper and a lower, an arrangement never reported previously in an extant or extinct echinoderm. Cover plates are absent and floor plates are separated along the perradial suture, creating a large permanent entrance to the interior of the oral area. The Tube Feet may have captured food particles that entered the oral area and/or enhanced respiration. The pentameral symmetry of the oral surface transitions to eight columns in which the plates are vertically offset resulting in a spiral appearance. This change in symmetry may reflect flexibility in the evolutionary development of the axial and extraxial zones in early echinoderm evolution
