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Sample records for acidic sea urchin

  1. Trophic ecology of the sea urchin elucidated from gonad fatty acids composition analysis

    López Jiménez, José Ángel; Barberá, C.; Fernández Jover, D.; González Silvera, D.; Hinz, H; Moranta, J.

    2011-01-01

    Abstract Irregular sea urchins such as the spatangoid Spatangus purpureus are important bioturbators that contribute to natural biogenic disturbance and the functioning of biogeochemical cycles in soft sediments. In the coastal waters of the Balearic Islands S. purpureus occurs in soft red algal beds, and can reach high densities. The diet of S. purpureus is unknown and it is particularly difficult to analyze the stomach contents of this group; therefore, we analyzed the fatty acid...

  2. Phosphoproteomes of Strongylocentrotus purpuratus shell and tooth matrix: identification of a major acidic sea urchin tooth phosphoprotein, phosphodontin

    Mann Matthias

    2010-02-01

    Full Text Available Abstract Background Sea urchin is a major model organism for developmental biology and biomineralization research. However, identification of proteins involved in larval skeleton formation and mineralization processes in the embryo and adult, and the molecular characterization of such proteins, has just gained momentum with the sequencing of the Strongylocentrotus purpuratus genome and the introduction of high-throughput proteomics into the field. Results The present report contains the determination of test (shell and tooth organic matrix phosphoproteomes. Altogether 34 phosphoproteins were identified in the biomineral organic matrices. Most phosphoproteins were specific for one compartment, only two were identified in both matrices. The sea urchin phosphoproteomes contained several obvious orthologs of mammalian proteins, such as a Src family tyrosine kinase, protein kinase C-delta 1, Dickkopf-1 and other signal transduction components, or nucleobindin. In most cases phosphorylation sites were conserved between sea urchin and mammalian proteins. However, the majority of phosphoproteins had no mammalian counterpart. The most interesting of the sea urchin-specific phosphoproteins, from the perspective of biomineralization research, was an abundant highly phosphorylated and very acidic tooth matrix protein composed of 35 very similar short sequence repeats, a predicted N-terminal secretion signal sequence, and an Asp-rich C-terminal motif, contained in [Glean3:18919]. Conclusions The 64 phosphorylation sites determined represent the most comprehensive list of experimentally identified sea urchin protein phosphorylation sites at present and are an important addition to the recently analyzed Strongylocentrotus purpuratus shell and tooth proteomes. The identified phosphoproteins included a major, highly phosphorylated protein, [Glean3:18919], for which we suggest the name phosphodontin. Although not sequence-related to such highly phosphorylated

  3. Trophic ecology of the sea urchin Spatangus purpureus elucidated from gonad fatty acids composition analysis.

    Barberá, C; Fernández-Jover, D; López Jiménez, J A; González Silvera, D; Hinz, H; Moranta, J

    2011-05-01

    Irregular sea urchins such as the spatangoid Spatangus purpureus are important bioturbators that contribute to natural biogenic disturbance and the functioning of biogeochemical cycles in soft sediments. In the coastal waters of the Balearic Islands S. purpureus occurs in soft red algal beds, and can reach high densities. The diet of S. purpureus is unknown and it is particularly difficult to analyze the stomach contents of this group; therefore, we analyzed the fatty acid (FA) composition of the gonads and potential food resources in order to assess the trophic relationships of this species. The FA profiles of the gonads of S. purpureus agree well with the FA composition of the potential trophic resources (algae and sediment) and reveals changes between localities with different available resources. Three polyunsaturated FAs mainly contributes in the composition in the S. purpureus gonads: eicosapentaenoic acid (C20:5n-3) and arachidonic acid (C20:4n-6), both abundant in the macroalgal material, and palmitoleic acid (C16:1n-7), which is characteristic of sediment samples. Trophic markers of bacterial input and carnivorous feeding were significantly more abundant in sea urchins caught on bottoms with less vegetation. The current study demonstrates that the FA content of S. purpureus gonads is a useful marker of diet, as differences in the profiles reflected the variations in detritus composition. The results of this study show that this species has omnivorous feeding behavior; however, viewed in conjunction with available abundance data the results suggest that phytodetritus found within algal beds is an important carbon source for this species. PMID:21334740

  4. Comparative effects of dietary sea urchin shell powder and feed additives on meat quality and fatty acid profiles of broiler breast meat

    Sam Churl Kim

    2015-08-01

    Full Text Available This study was a small pen trial in which we investigated comparative effects of dietary sea urchin shell powder and feed additives on meat quality and fatty acid profiles of broiler breast meat. A total of 108 male broilers were assigned to 3 groups (control, 1% sea urchin shell powder, and 1% feed additives with 3 replicates of 12 chicks per pen in a completely randomized design for 28 days. The following parameters have been investigated: proximate composition (DM, CP, EE, and ash, physicochemical properties (pH, TBARS, cooking loss and DPPH radical scavenging, meat color and fatty acid profiles. No remarkable effects between treatment and storage day were observed for proximate composition, physicochemical properties, meat color and fatty acid profiles. In conclusion, diets with 1% sea urchin shell powder have the ability to increase DPPH radical scavenging and unsaturated fatty acid, indicating an opportunity for partial diet substitution in comparison with 1% feed additives.

  5. The sea urchin immune system

    LC Smith

    2006-05-01

    Full Text Available Metchnikoff’s use of sea star larvae to observe encapsulation and phagocytosis, which was followedmuch later by allograft rejection kinetics, revealed that echinoderms had an innate immune system thatwas lacking of adaptive attributes. Larval sea urchins mount defenses in response to contact withmicrobes, which are mediated by phagocytic blastocoelar cells and pigment cells. In the adult, thecoelomocytes mediate immune responses through phagocytosis and encapsulation of foreign particles inaddition to degranulation of antimicrobial molecules. Molecular analysis of immune functions in the seaurchin has demonstrated a complement system that appears to have multiple alternative pathways andseveral activators of the lectin pathway, but may be missing the terminal pathway. Other genes andproteins involved in the sea urchin immunity include expanded sets of lectins, proteins with scavengerreceptor cysteine-rich repeats, Toll-like receptors and associated signalling proteins. A vast array ofproteins belonging to the 185/333 family are expressed in coelomocytes in response to lipopolysaccharideand show a surprising level of diversity. The sea urchin innate immune system has a number of largegene families with unexpected complexities and elevated levels of diversification.

  6. Spiculisporic Acids B–D, Three New γ-Butenolide Derivatives from a Sea Urchin-Derived Fungus Aspergillus sp. HDf2

    Xian-Ming Tang; Quan-Ying Feng; Ming-Qiu Yang; Ming-Hui Shen; Tian-Mi Liu; Rong Wang; Xiang-Min Li

    2012-01-01

    Three new γ-butenolide derivatives 1–3, named spiculisporic acids B–D, were isolated from the culture of Aspergillus sp. HDf2, a marine-derived fungus that resides in the sea urchin, Anthocidaris crassispina. The structures of 1–3 were elucidated on the basis of spectroscopic methods, including MS and 2D NMR techniques. Their in vitro cytotoxic activities against two cell lines (SGC-7901, human gastric adenocarcinoma and SPC-A-1, human lung adenocarcinom...

  7. Isolation and properties of the acid site-specific endonuclease from mature eggs of the sea urchin Strongylocentrotus intermedius

    An acid site-specific endonuclease has been detected in mature sea urchin eggs and cells of embryos at early stages of differentiation. Fractionation with ammonium sulfate, followed by chromatography on columns with DEAE, phosphocellulose, and hydroxyapatite resulted in an 18,000-fold purification. The molecular weight of the enzyme was determined at ∼ 29,000, the optimum pH 5.5. The activity of the enzyme does not depend on divalent metal ions, EDTA, ATP, and tRNA, but it is modulated to a substantial degree by NaCl. The maximum rate of cleavage of the DNA supercoil (form I) is observed at 100 mM NaCl. Increasing the NaCl concentration to 350 mM only slightly lowers the rate of cleavage of form I, yielding form II, but entirely suppresses the accumulation of form III. Restriction analysis of the products of enzymatic hydrolysis of Co1E1 and pBR322 DNA showed that at the early stages of hydrolysis the enzyme exhibits pronounced specificity for definite sites, the number of which is 12 for Co1 E1 DNA and 8 sites for pBR322 DNA

  8. Could the acid-base status of Antarctic sea urchins indicate a better-than-expected resilience to near-future ocean acidification?

    Collard, Marie; De Ridder, Chantal; David, Bruno; Dehairs, Frank; Dubois, Philippe

    2015-02-01

    Increasing atmospheric carbon dioxide concentration alters the chemistry of the oceans towards more acidic conditions. Polar oceans are particularly affected due to their low temperature, low carbonate content and mixing patterns, for instance upwellings. Calcifying organisms are expected to be highly impacted by the decrease in the oceans' pH and carbonate ions concentration. In particular, sea urchins, members of the phylum Echinodermata, are hypothesized to be at risk due to their high-magnesium calcite skeleton. However, tolerance to ocean acidification in metazoans is first linked to acid-base regulation capacities of the extracellular fluids. No information on this is available to date for Antarctic echinoderms and inference from temperate and tropical studies needs support. In this study, we investigated the acid-base status of 9 species of sea urchins (3 cidaroids, 2 regular euechinoids and 4 irregular echinoids). It appears that Antarctic regular euechinoids seem equipped with similar acid-base regulation systems as tropical and temperate regular euechinoids but could rely on more passive ion transfer systems, minimizing energy requirements. Cidaroids have an acid-base status similar to that of tropical cidaroids. Therefore Antarctic cidaroids will most probably not be affected by decreasing seawater pH, the pH drop linked to ocean acidification being negligible in comparison of the naturally low pH of the coelomic fluid. Irregular echinoids might not suffer from reduced seawater pH if acidosis of the coelomic fluid pH does not occur but more data on their acid-base regulation are needed. Combining these results with the resilience of Antarctic sea urchin larvae strongly suggests that these organisms might not be the expected victims of ocean acidification. However, data on the impact of other global stressors such as temperature and of the combination of the different stressors needs to be acquired to assess the sensitivity of these organisms to global

  9. Spiculisporic Acids B–D, Three New γ-Butenolide Derivatives from a Sea Urchin-Derived Fungus Aspergillus sp. HDf2

    Xian-Ming Tang

    2012-11-01

    Full Text Available Three new γ-butenolide derivatives 1–3, named spiculisporic acids B–D, were isolated from the culture of Aspergillus sp. HDf2, a marine-derived fungus that resides in the sea urchin, Anthocidaris crassispina. The structures of 1–3 were elucidated on the basis of spectroscopic methods, including MS and 2D NMR techniques. Their in vitro cytotoxic activities against two cell lines (SGC-7901, human gastric adenocarcinoma and SPC-A-1, human lung adenocarcinoma and inhibitory activities against Staphylococcus aureus ATCC 51650 were investigated.

  10. Spiculisporic acids B–D, three new γ-butenolide derivatives from a sea urchin-derived fungus Aspergillus sp. HDf2.

    Wang, Rong; Liu, Tian-Mi; Shen, Ming-Hui; Yang, Ming-Qiu; Feng, Quan-Ying; Tang, Xian-Ming; Li, Xiang-Min

    2012-01-01

    Three new γ-butenolide derivatives 1–3, named spiculisporic acids B–D, were isolated from the culture of Aspergillus sp. HDf2, a marine-derived fungus that resides in the sea urchin, Anthocidaris crassispina. The structures of 1–3 were elucidated on the basis of spectroscopic methods, including MS and 2D NMR techniques. Their in vitro cytotoxic activities against two cell lines (SGC-7901, human gastric adenocarcinoma and SPC-A-1, human lung adenocarcinoma) and inhibitory activities against Staphylococcus aureus ATCC 51650 were investigated. PMID:23128094

  11. Biobanking of a Marine Invertebrate Model Organism: The Sea Urchin

    Estefania Paredes

    2016-01-01

    The sea urchin has long been used as an invertebrate model organism in developmental biology, membrane transport and sperm oocyte interactions, and for the assessment of marine pollution. This review explores the effects of cryopreservation and biobanking in the biology and development of sea urchins, all the way from germaplasm through to juveniles. This review will provide an integral view of the process and all that is known so far about the biology of cryopreserved sea urchins, as well as...

  12. Sea urchin vault structure, composition, and differential localization during development

    Dickey-Sims Carrie; Lang Jennifer; Makabi Miriam; Stewart Phoebe L; Robertson Anthony J; Coffman James A; Suprenant Kathy A

    2005-01-01

    Abstract Background Vaults are intriguing ribonucleoprotein assemblies with an unknown function that are conserved among higher eukaryotes. The Pacific coast sea urchin, Strongylocentrotus purpuratus, is an invertebrate model organism that is evolutionarily closer to humans than Drosophila and C. elegans, neither of which possesses vaults. Here we compare the structures of sea urchin and mammalian vaults and analyze the subcellular distribution of vaults during sea urchin embryogenesis. Resul...

  13. Actin gene expression in developing sea urchin embryos.

    Crain, W R; Durica, D S; Van Doren, K

    1981-01-01

    We show that the synthesis of actin is regulated developmentally during early sea urchin embryogenesis and that the level of synthesis of this protein parallels the steady-state amounts of the actin messenger ribonucleic acids (RNA). An in vitro translation and RNA blotting analysis of embryo RNA from several stages of early development indicated that during the first 8 h after fertilization there was a low and relatively constant level of actin messenger RNA in the embryo. Between 8 and 13 h...

  14. Phytopigments and fatty acids in the gut of the deposit-feeding heart urchin Echinocardium cordatum in the southern North Sea: Selective feeding and its contribution to the benthic carbon budget

    Boon, A.R.; Duineveld, G.C.A.

    2012-01-01

    As part of a broader study on benthic–pelagic coupling in the southern North Sea, specimens of the common heart urchin Echinocardium cordatum were sampled for analyses on phytopigments and fatty acids in their guts. Results were interpreted in the context of feeding and ecological functioning of the heart urchins in the benthic system. Ingestion selection factors for both component groups were relatively high, 5 to 9 for chlorophyll a and 9 to 130 for total fatty acids. The data point to at l...

  15. Toxic Diatom Aldehydes Affect Defence Gene Networks in Sea Urchins

    Varrella, Stefano; Ruocco, Nadia; Ianora, Adrianna; Bentley, Matt G.; Costantini, Maria

    2016-01-01

    Marine organisms possess a series of cellular strategies to counteract the negative effects of toxic compounds, including the massive reorganization of gene expression networks. Here we report the modulated dose-dependent response of activated genes by diatom polyunsaturated aldehydes (PUAs) in the sea urchin Paracentrotus lividus. PUAs are secondary metabolites deriving from the oxidation of fatty acids, inducing deleterious effects on the reproduction and development of planktonic and benthic organisms that feed on these unicellular algae and with anti-cancer activity. Our previous results showed that PUAs target several genes, implicated in different functional processes in this sea urchin. Using interactomic Ingenuity Pathway Analysis we now show that the genes targeted by PUAs are correlated with four HUB genes, NF-κB, p53, δ-2-catenin and HIF1A, which have not been previously reported for P. lividus. We propose a working model describing hypothetical pathways potentially involved in toxic aldehyde stress response in sea urchins. This represents the first report on gene networks affected by PUAs, opening new perspectives in understanding the cellular mechanisms underlying the response of benthic organisms to diatom exposure. PMID:26914213

  16. Pantropic retroviruses as a transduction tool for sea urchin embryos.

    Core, Amanda B; Reyna, Arlene E; Conaway, Evan A; Bradham, Cynthia A

    2012-04-01

    Sea urchins are an important model for experiments at the intersection of development and systems biology, and technical innovations that enhance the utility of this model are of great value. This study explores pantropic retroviruses as a transduction tool for sea urchin embryos, and demonstrates that pantropic retroviruses infect sea urchin embryos with high efficiency and genomically integrate at a copy number of one per cell. We successfully used a self-inactivation strategy to both insert a sea urchin-specific enhancer and disrupt the endogenous viral enhancer. The resulting self-inactivating viruses drive global and persistent gene expression, consistent with genomic integration during the first cell cycle. Together, these data provide substantial proof of principle for transduction technology in sea urchin embryos. PMID:22431628

  17. Expression of Pigment Cell-Specific Genes in the Ontogenesis of the Sea Urchin Strongylocentrotus intermedius.

    Ageenko, Natalya V; Kiselev, Konstantin V; Odintsova, Nelly A

    2011-01-01

    One of the polyketide compounds, the naphthoquinone pigment echinochrome, is synthesized in sea urchin pigment cells. We analyzed polyketide synthase (pks) and sulfotransferase (sult) gene expression in embryos and larvae of the sea urchin Strongylocentrotus intermedius from various stages of development and in specific tissues of the adults. We observed the highest level of expression of the pks and sult genes at the gastrula stage. In unfertilized eggs, only trace amounts of the pks and sult transcripts were detected, whereas no transcripts of these genes were observed in spermatozoids. The addition of shikimic acid, a precursor of naphthoquinone pigments, to zygotes and embryos increased the expression of the pks and sult genes. Our findings, including the development of specific conditions to promote pigment cell differentiation of embryonic sea urchin cells in culture, represent a definitive study on the molecular signaling pathways that are involved in the biosynthesis of pigments during sea urchin development. PMID:21804858

  18. Sea urchin vault structure, composition, and differential localization during development

    Dickey-Sims Carrie

    2005-02-01

    Full Text Available Abstract Background Vaults are intriguing ribonucleoprotein assemblies with an unknown function that are conserved among higher eukaryotes. The Pacific coast sea urchin, Strongylocentrotus purpuratus, is an invertebrate model organism that is evolutionarily closer to humans than Drosophila and C. elegans, neither of which possesses vaults. Here we compare the structures of sea urchin and mammalian vaults and analyze the subcellular distribution of vaults during sea urchin embryogenesis. Results The sequence of the sea urchin major vault protein (MVP was assembled from expressed sequence tags and genome traces, and the predicted protein was found to have 64% identity and 81% similarity to rat MVP. Sea urchin MVP includes seven ~50 residue repeats in the N-terminal half of the protein and a predicted coiled coil domain in the C-terminus, as does rat MVP. A cryoelectron microscopy (cryoEM reconstruction of isolated sea urchin vaults reveals the assembly to have a barrel-shaped external structure that is nearly identical to the rat vault structure. Analysis of the molecular composition of the sea urchin vault indicates that it contains components that may be homologs of the mammalian vault RNA component (vRNA and protein components (VPARP and TEP1. The sea urchin vault appears to have additional protein components in the molecular weight range of 14–55 kDa that might correspond to molecular contents. Confocal experiments indicate a dramatic relocalization of MVP from the cytoplasm to the nucleus during sea urchin embryogenesis. Conclusions These results are suggestive of a role for the vault in delivering macromolecules to the nucleus during development.

  19. Determination of sialic acids in immune system cells (coelomocytes) of sea urchin, Paracentrotus lividus, using capillary LC-ESI-MS/MS.

    İzzetoğlu, Savaş; Şahar, Umut; Şener, Ecem; Deveci, Remziye

    2014-01-01

    Coelomocytes are considered to be immune effectors of sea urchins. Coelomocytes are the freely circulating cells in the body fluid contained in echinoderm coelom and mediate the cellular defence responses to immune challenges by phagocytosis, encapsulation, cytotoxicity and the production of antimicrobial agents. Coelomocytes have the ability to recognize self from non-self. Considering that sialic acids play important roles in immunity, we determined the presence of sialic acid types in coelomocytes of Paracentrotus lividus. Homogenized coelomocytes were kept in 2 M aqueous acetic acid at 80 °C for 3 h to liberate sialic acids. Sialic acids were determined by derivatization with 1,2-diamino-4,5-methylenediaoxy-benzene dihydrochloride (DMB) followed by capillary liquid-chromatography-electrospray ionization/tandem mass spectrometry (CapLC-ESI-MS/MS). Standard sialic acids; Neu5Ac, Neu5Gc, KDN and bovine submaxillary mucin showing a variety of sialic acids were used to confirm sialic acids types. We found ten different types of sialic acids (Neu5Gc, Neu5Ac, Neu5Gc9Ac, Neu5Gc8Ac, Neu5,9Ac2, Neu5,7Ac2, Neu5,8Ac2, Neu5,7,9Ac3, Neu5Gc7,9Ac2, Neu5Gc7Ac) isolated in limited amounts from total coelomocyte population. Neu5Gc type of sialic acids in coelomocytes was the most abundant type sialic acid when compared with other types. This is the first report on the presence of sialic acid types in coelomocytes of P. lividus using CapLC-ESI-MS/MS-Ion Trap system (Capillary Liquid Chromatography-Electrospray Ionization/Tandem Mass Spectrometry). PMID:24215912

  20. Biobanking of a Marine Invertebrate Model Organism: The Sea Urchin

    Estefania Paredes

    2016-01-01

    Full Text Available The sea urchin has long been used as an invertebrate model organism in developmental biology, membrane transport and sperm oocyte interactions, and for the assessment of marine pollution. This review explores the effects of cryopreservation and biobanking in the biology and development of sea urchins, all the way from germaplasm through to juveniles. This review will provide an integral view of the process and all that is known so far about the biology of cryopreserved sea urchins, as well as provide an insight on the applications of the biobanking of these model organisms.

  1. Can sea urchins beat the heat? Sea urchins, thermal tolerance and climate change

    Elizabeth Sherman

    2015-06-01

    Full Text Available The massive die-off of the long-spined sea urchin, Diadema antillarum, a significant reef grazer, in the mid 1980s was followed by phase shifts from coral dominated to macroalgae dominated reefs in the Caribbean. While Diadema populations have recovered in some reefs with concomitant increases in coral cover, the additional threat of increasing temperatures due to global climate change has not been investigated in adult sea urchins. In this study, I measured acute thermal tolerance of D. antillarum and that of a sympatric sea urchin not associated with coral cover, Echinometra lucunter, over winter, spring, and summer, thus exposing them to substantial natural thermal variation. Animals were taken from the wild and placed in laboratory tanks in room temperature water (∼22 °C that was then heated at 0.16–0.3 °C min−1 and the righting behavior of individual sea urchins was recorded. I measured both the temperature at which the animal could no longer right itself (TLoR and the righting time at temperatures below the TLoR. In all seasons, D. antillarum exhibited a higher mean TLoR than E. lucunter. The mean TLoR of each species increased with increasing environmental temperature revealing that both species acclimatize to seasonal changes in temperatures. The righting times of D. antillarum were much shorter than those of E. lucunter. The longer relative spine length of Diadema compared to that of Echinometra may contribute to their shorter righting times, but does not explain their higher TLoR. The thermal safety margin (the difference between the mean collection temperature and the mean TLoR was between 3.07–3.66 °C for Echinometra and 3.79–5.67 °C for Diadema. While these thermal safety margins exceed present day temperatures, they are modest compared to those of temperate marine invertebrates. If sea temperatures increase more rapidly than can be accommodated by the sea urchins (either by genetic adaptation, phenotypic plasticity

  2. For the Classroom: The Sea Urchin Fertilization and Embryology Lab.

    Brevoort, Douglas

    1984-01-01

    The sea urchin provides an ideal embryology laboratory because it is visually representative of the fertilization process in higher animals. Procedures for conducting such a laboratory (including methods for securing specimens) are provided. (JN)

  3. The Sea Urchin Embryo: A Remarkable Classroom Tool.

    Oppenheimer, Steven B.

    1989-01-01

    Discussed are the uses of sea urchins in research and their usefulness and advantages in the classroom investigation of embryology. Ideas for classroom activities and student research are presented. Lists 25 references. (CW)

  4. Sea Urchin Recruitment: Effect of Substrate Selection on Juvenile Distribution

    Cameron, R. A.; Schroeter, S. C.

    1980-01-01

    Intertidal field observations have shown that juvenile purple sea urchins Strongylocentwtus purpuratus are found in higher densities near adults . The same is true for subtidal populations of juvenile red sea urchins 5. franciscanus. These distribution patterns could be influenced by any of three elements: substrate selection, early juvenile mortality or juvenile migration. Using laboratory-reared larvae, we conducted experiments designed to gauge the effect of substrate selection on ju...

  5. Phytopigments and fatty acids in the gut of the deposit-feeding heart urchin Echinocardium cordatum in the southern North Sea: Selective feeding and its contribution to the benthic carbon budget

    Boon, Arjen R.; Duineveld, Gerard C. A.

    2012-01-01

    As part of a broader study on benthic-pelagic coupling in the southern North Sea, specimens of the common heart urchin Echinocardium cordatum were sampled for analyses on phytopigments and fatty acids in their guts. Results were interpreted in the context of feeding and ecological functioning of the heart urchins in the benthic system. Ingestion selection factors for both component groups were relatively high, 5 to 9 for chlorophyll a and 9 to 130 for total fatty acids. The data point to at least partially different sources of the pigments and of the fatty acids. Next to algal detritus, small infauna relatively rich in fatty acids might be preferentially co-ingested with the detritus. Due to digestive breakdown and absorption, the concentrations of pigments and fatty acids were importantly decreased, indicating a rather high digestion efficiency for this subsurface deposit feeder, up to 80%. The results indicate that E. cordatum increases its energy acquisition by strong selectivity and a high digestive efficiency. Optimal foraging is likely to apply on deposit-feeding invertebrates in relatively food-rich coastal environments as much as it does in the food-poor deep-sea environment. Using chlorophyll a as a proxy for carbon, the contribution of the urchin population to the momentary benthic carbon budget was calculated at 7% to 42%.

  6. Cryopreservation of sea urchin (Evechinus chloroticus) sperm.

    Adams, Serean L; Hessian, Paul A; Mladenov, Philip V

    2004-01-01

    A method was developed for cryopreserving sperm of the sea urchin, Evechinus chloroticus. Sperm fertilisation ability, mitochondrial function and membrane integrity were assessed before and after cryopreservation. Highest post-thaw fertilisation ability was achieved with lower concentrations (2.5%-7.5%) of dimethyl sulphoxide (DMSO). In contrast, post-thaw mitochondrial function and membrane integrity were higher for sperm frozen in intermediate and high DMSO concentrations (5%-15%). Surprisingly, some sperm frozen in seawater only, without DMSO, were able to survive post-thawing, although the fertilisation ability (10(6) sperm/ml; approximately 50% fertilisation), mitochondrial function and membrane integrity of these sperm were notably lower than of sperm frozen with DMSO (10(6) sperm cells/ml; 2.5%-7.5% DMSO; >85% fertilisation) at the concentrations tested. Amongst sperm from individual males, fertilisation ability varied before and after cryopreservation for both males frozen with and without cryoprotectant. Specific differences among males also varied. Sperm mitochondrial function and membrane integrity was similar among males before cryopreservation but differed considerably after cryopreservation. Cryopreserved sperm were able to fertilise eggs and develop to pluteus stage larvae. This study has practical applications and will provide benefits such as reduced broodstock conditioning costs, control of parental input and opportunities for hybridisation studies. PMID:15375439

  7. Unique system of photoreceptors in sea urchin tube feet

    Ullrich-Lüter, Esther M; Dupont, Sam; Arboleda, Enrique; Hausen, Harald; Arnone, Maria Ina

    2011-01-01

    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. PMID:21536888

  8. Involvement of the cell-specific pigment genes pks and sult in bacterial defense response of sea urchins Strongylocentrotus intermedius.

    Kiselev, Konstantin V; Ageenko, Natalya V; Kurilenko, Valeria V

    2013-03-26

    Bacterial infections are one of the most important problems in mass aquaculture, causing the loss of millions of juvenile organisms. We isolated 22 bacterial strains from the cavity fluid of the sea urchin Strongylocentrotus pallidus and used phylogenetic analysis based on 16S rRNA gene sequences to separate the bacterial strains into 9 genera (Aliivibrio, Bizionia, Colwellia, Olleya, Paenibacillus, Photobacterium, Pseudoalteromonas, Shewanella, and Vibrio). Incubating Strongylocentrotus intermedius larvae with a strain from each of the 9 bacterial genera, we investigated the viability of the larvae, the amount of pigment cells, and the level of polyketide synthase (pks) and sulfotransferase (sult) gene expression. Results of the assay on sea urchin development showed that all bacterial strains, except Pseudoalteromonas and Bizionia, suppressed sea urchin development (resulting in retardation of the embryos' development with cellular disorders) and reduced cell viability. We found that pks expression in the sea urchin larvae after incubation with the bacteria of 9 tested genera was significantly increased, while the sult expression was increased only after the treatment with Pseudoalteromonas and Shewanella. Shikimic acid, which is known to activate the biosynthesis of naphthoquinone pigments, increased the tolerance of the sea urchin embryos to the bacteria. In conclusion, we show that the cell-specific pigment genes pks and sult are involved in the bacterial defense response of sea urchins. PMID:23548362

  9. Isolation and Characterization of Antibacterial Compounds from Sea Urchin

    Febrina Olivia Akerina,

    2015-06-01

    Full Text Available method, toxicity potential using brine shrimp lethality test (BSLT method, bioactive compound using phytochemical method, and proximate composition by AOAC. This research was devided into two phases, the preliminary research was to determine the best body part of sea urchin showing antibacterial activity. Sea urchins were collected from Pramuka Island and extracted by meseration method. For the preliminary research, gonad extract showed the high antibacterial activity against E. coli and S. aureus at 1.83 ± 0.74 mm and 1.5 mm, respectively. The main research includes the determination of proximate composition, toxicity, bioactive compound, and antibacterial activity from the best body part of sea urchin. The proximate composition from gonad of sea urchin showed that water content 64.97 ± 0.08%; ash 2.72 ± 0.13%; lipid 19.73 ± 0.04%; protein 12.26 ± 0.3%, and 0.33 ± 0.17%, respectively. The detected bioactive compounds from the three different solvents of gonads extracts were steroid, triterpenoid and saponin. The result of lethal toxicity (LC50 from the three gonads extract was 471.861 ppm (n-hexane, 563.226 ppm (ethyl acetate and 577.531 ppm (methanolic, respectively. Gonads ethyl acetate extracts showed the highest antibacterial activity than n-hexane and methanolic extract, its inhibition zone was 2.71 mm against S. aureus and 4.13 against E. coli.

  10. Sea urchin immune cells as sentinels of environmental stress.

    Pinsino, Annalisa; Matranga, Valeria

    2015-03-01

    Echinoderms, an ancient and very successful phylum of marine invertebrates, play a central role in the maintenance of ecosystem integrity and are constantly exposed to environmental pressure, including: predation, changes in temperature and pH, hypoxia, pathogens, UV radiation, metals, toxicants, and emerging pollutants like nanomaterials. The annotation of the sea urchin genome, so closely related to humans and other vertebrate genomes, revealed an unusually complex immune system, which may be the basis for why sea urchins can adapt to different marine environments and survive even in hazardous conditions. In this review, we give a brief overview of the morphological features and recognized functions of echinoderm immune cells with a focus on studies correlating stress and immunity in the sea urchin. Immune cells from adult Paracentrotus lividus, which have been introduced in the last fifteen years as sentinels of environmental stress, are valid tools to uncover basic molecular and regulatory mechanisms of immune responses, supporting their use in immunological research. Here we summarize laboratory and field studies that reveal the amenability of sea urchin immune cells for toxicological testing. PMID:25463510

  11. Sea urchin granuloma Granulomas por ouriços-do-mar

    André Luiz Rossetto; Jamesson de Macedo Mora; Vidal Haddad Junior

    2006-01-01

    Injuries caused by venomous and poisonous aquatic animals may provoke important morbidity in humans. The phylum Echinoderma include more than 6000 species of starfish, sea urchins, sand dollars, and sea cucumbers some of which have been found responsible for injuries to humans. Initial injuries by sea urchins are associated with trauma and envenomation, but later effects can be observed. Sea urchin granuloma is a chronic granulomatous skin disease caused by frequent and successive penetration...

  12. Sea urchin fisheries, management and policy review (Activity A4.2.1 of the URCHIN project)

    James, Philip; Noble, Chris; Hannon, Colin; STEFANSSON, Gudmundur; Thórarinsdóttir, Gudrún; Sloane, Roderick; Ziemer, Nikoline; Lochead, Janet

    2016-01-01

    This report gives a brief introduction to the URCHIN project, funded by the Northern Peripheries and Arctic Programme (NPA). The scope of the report is also outlined. This is followed by a summary of the sea urchin fishery management techniques that are used in sea urchin fisheries around the world. These are listed in order of size of the fisheries and include a brief description of the history of the fishery and what management practices have led to the current state of the fishery....

  13. Phytopigments and fatty acids in the gut of the deposit-feeding heart urchin

    Boon, A.R.; Duineveld, G.C.A.

    2012-01-01

    As part of a broader study on benthic–pelagic coupling in the southern North Sea, specimens of the common heart urchin Echinocardium cordatum were sampled for analyses on phytopigments and fatty acids in their guts. Results were interpreted in the context of feeding and ecological functioni

  14. Cellular and molecular mechanisms of negligible senescence: insight from the sea urchin

    Bodnar, Andrea G.

    2014-01-01

    Sea urchins exhibit a very different life history from humans and short-lived model animals and therefore provide the opportunity to gain new insight into the complex process of aging. Sea urchins grow indeterminately, regenerate damaged appendages, and reproduce throughout their lifespan. Some species show no increase in mortality rate at advanced ages. Nevertheless, different species of sea urchins have very different reported lifespans ranging from 4 to more than 100 years, thus providing ...

  15. Mass isolation and culture of sea urchin micromeres.

    Harkey, M A; Whiteley, A H

    1985-02-01

    A procedure is described for large-scale isolation of micromeres from 16-cell stage sea urchin embryos. One to two grams of greater than 99% pure, viable micromeres (2.3 to 4.6 X 10(8) cells) are routinely isolated in a single preparation. In culture, these cells uniformly proceed through their normal development, in synchrony with micromeres in whole embryos, ultimately differentiating typical larval skeletal structures. The attributes of this procedure are: (a) the very early time of isolation of the cells, directly after the division that establishes the cell line; (b) the large yield of cells; (c) the purity of the preparation of cell; and (d) their synchronous development in culture through skeletogenesis. The procedure greatly aids in making sea urchin micromeres a favorable material for molecular analysis of development. PMID:4008427

  16. The genome of the sea urchin Strongylocentrotus purpuratus.

    SEA URCHIN GENOME SEQUENCING CONSORTIUM; SODERGREN E; WEINSTOCK GM; DAVIDSON EH; CAMERON RA; GIBBS RA; ANGERER RC; ANGERER LM; ARNONE MI; BURGESS DR; BURKE RD; COFFMAN JA; Dean, M.; ELPHICK MR; ETTENSOHN CA

    2006-01-01

    We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or ...

  17. A Genomic View of the Sea Urchin Nervous System

    Burke, RD; Angerer, LM; Elphick, MR; Humphrey, GW; Yaguchi, S; Kiyama, T.; Liang, S.; Mu, X.; Agca, C; Klein, WH; Brandhorst, BP; Rowe, M.; Wilson, K.; Churcher, AM; Taylor, JS

    2006-01-01

    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...

  18. Juvenile skeletogenesis in anciently diverged sea urchin clades

    Gao, Feng; Thompson, Jeffrey R.; Petsios, Elizabeth; Erkenbrack, Eric; Moats, Rex A.; Bottjer, David J.; Davidson, Eric H.

    2015-01-01

    Mechanistic understanding of evolutionary divergence in animal body plans devolves from analysis of those developmental processes that, in forms descendant from a common ancestor, are responsible for their morphological differences. The last common ancestor of the two extant subclasses of sea urchins, i.e., euechinoids and cidaroids, existed well before the Permian/Triassic extinction (252 mya). Subsequent evolutionary divergence of these clades offers in principle a rare opportunity to solve...

  19. Sea Urchin as an alternative feed for fish.

    Omolo, S.O.

    1991-01-01

    The Objective of the present study was to investigate the effect of sea urchin stuff as an alternative fish food of Oreochromis niloticus during growth. This African cichlid is widely distributed where temperature and food are suitable for ill growth and reproduction. In many Countries, it was introduced for vegetation control, pond culture, and recreational and commercial fishing because of its excellent aqua culture potential, fast growth, omnivorous feeding habits and tolerance to low wate...

  20. Skeletogenesis in sea urchin larvae under modified gravity conditions

    Marthy, H.-J.; Gasset, G.; Tixador, R.; Eche, B.; Schatt, P.; Dessommes, A.; Marthy, U.; Bacchieri, R.

    From many points of view, skeletogenesis in sea urchins has been well described. Based on this scientific background and considering practical aspects of sea urchin development (i.e. availability of material, size of larvae, etc.), we wanted to know whether orderly skeletogenesis requires the presence of gravity. The objective has been approached by three experiments successfully performed under genuine microgravity conditions (in the STS-65 IML-2 mission of 1994; in the Photon-10 IBIS mission of 1995 and in the STS-76 S/MM-03 mission of 1996). Larvae of the sea urchin Sphaerechinus granularis were allowed to develop in microgravity conditions for several days from blastula stage onwards (onset of skeletogenesis). At the end of the missions, the recovered skeletal structures were studied with respect to their mineral composition, architecture and size. Live larvae were also recovered for post-flight culture. The results obtained clearly show that the process of mineralisation is independent of gravity: that is, the skeletogenic cells differentiate correctly in microgravity. However, abnormal skeleton architectures were encountered, particularly in the IML-2 mission, indicating that the process of positioning of the skeletogenic cells may be affected, directly or indirectly, by environmental factors, including gravity. Larvae exposed to microgravity from blastula to prism/early pluteus stage for about 2 weeks (IBIS mission), developed on the ground over the next 2 months into normal metamorphosing individuals.

  1. Robustness and Accuracy in Sea Urchin Developmental Gene Regulatory Networks

    Ben-Tabou de-Leon, Smadar

    2016-01-01

    Developmental gene regulatory networks robustly control the timely activation of regulatory and differentiation genes. The structure of these networks underlies their capacity to buffer intrinsic and extrinsic noise and maintain embryonic morphology. Here I illustrate how the use of specific architectures by the sea urchin developmental regulatory networks enables the robust control of cell fate decisions. The Wnt-βcatenin signaling pathway patterns the primary embryonic axis while the BMP signaling pathway patterns the secondary embryonic axis in the sea urchin embryo and across bilateria. Interestingly, in the sea urchin in both cases, the signaling pathway that defines the axis controls directly the expression of a set of downstream regulatory genes. I propose that this direct activation of a set of regulatory genes enables a uniform regulatory response and a clear cut cell fate decision in the endoderm and in the dorsal ectoderm. The specification of the mesodermal pigment cell lineage is activated by Delta signaling that initiates a triple positive feedback loop that locks down the pigment specification state. I propose that the use of compound positive feedback circuitry provides the endodermal cells enough time to turn off mesodermal genes and ensures correct mesoderm vs. endoderm fate decision. Thus, I argue that understanding the control properties of repeatedly used regulatory architectures illuminates their role in embryogenesis and provides possible explanations to their resistance to evolutionary change. PMID:26913048

  2. Male chromosomes of sea urchin hybrid andromerogones created with cryopreserved sperm.

    Saotome, Kyoko; Kamimura, Ryuichi; Kurokura, Hisashi; Hirano, Reijiro

    2002-02-01

    We developed a method for preparing male chromosomes from sea urchin hybrid andromerogones created with cryopreserved sperm. We obtained hybrid andromerogones by heterospermic insemination of Hemicentrotus pulcherrimus non-nucleate egg fragments produced by centrifuging unfertilized eggs in a stepwise saccharose density gradient. The hybrid andromerogones showed cleavage rates of 1%-93%, cleaved successively into two- and four- blastomeres and developed to early blastulae. The morulae or early blastulae were treated with colchicine (0.1-1.0 mg/ml), dissociated into single blastomeres by pippeting, swollen with 7%-10% sodium citrate for 10 min and fixed with methanol:acetic acid (3:1). The fixed cells were dropped on slides and air-dried. The andromerogones for 5 sperm species showed a half of their respective diploid chromosome numbers without chromosome elimination. This method is applicable for analysis of the haploid male chromosome complement in sea urchin species for which only sperm can be obtained. PMID:12012781

  3. Juvenile skeletogenesis in anciently diverged sea urchin clades.

    Gao, Feng; Thompson, Jeffrey R; Petsios, Elizabeth; Erkenbrack, Eric; Moats, Rex A; Bottjer, David J; Davidson, Eric H

    2015-04-01

    Mechanistic understanding of evolutionary divergence in animal body plans devolves from analysis of those developmental processes that, in forms descendant from a common ancestor, are responsible for their morphological differences. The last common ancestor of the two extant subclasses of sea urchins, i.e., euechinoids and cidaroids, existed well before the Permian/Triassic extinction (252 mya). Subsequent evolutionary divergence of these clades offers in principle a rare opportunity to solve the developmental regulatory events underlying a defined evolutionary divergence process. Thus (i) there is an excellent and fairly dense (if yet incompletely analyzed) fossil record; (ii) cladistically confined features of the skeletal structures of modern euechinoid and cidaroid sea urchins are preserved in fossils of ancestral forms; (iii) euechinoids and cidaroids are among current laboratory model systems in molecular developmental biology (here Strongylocentrotus purpuratus [Sp] and Eucidaris tribuloides [Et]); (iv) skeletogenic specification in sea urchins is uncommonly well understood at the causal level of interactions of regulatory genes with one another, and with known skeletogenic effector genes, providing a ready arsenal of available molecular tools. Here we focus on differences in test and perignathic girdle skeletal morphology that distinguish all modern euechinoid from all modern cidaroid sea urchins. We demonstrate distinct canonical test and girdle morphologies in juveniles of both species by use of SEM and X-ray microtomography. Among the sharply distinct morphological features of these clades are the internal skeletal structures of the perignathic girdle to which attach homologous muscles utilized for retraction and protraction of Aristotles׳ lantern and its teeth. We demonstrate that these structures develop de novo between one and four weeks after metamorphosis. In order to study the underlying developmental processes, a method of section whole mount in

  4. The sea urchin (Strongylocentrotus purpuratus test and spine proteomes

    Mann Karlheinz

    2008-08-01

    Full Text Available Abstract Background The organic matrix of biominerals plays an important role in biomineral formation and in determining biomineral properties. However, most components of biomineral matrices remain unknown at present. In sea urchin, which is an important model organism for developmental biology and biomineralization, only few matrix components have been identified and characterized at the protein level. The recent publication of the Strongylocentrotus purpuratus genome sequence rendered possible not only the identification of possible matrix proteins at the gene level, but also the direct identification of proteins contained in matrices of skeletal elements by in-depth, high-accuracy, proteomic analysis. Results We identified 110 proteins as components of sea urchin test and spine organic matrix. Fourty of these proteins occurred in both compartments while others were unique to their respective compartment. More than 95% of the proteins were detected in sea urchin skeletal matrices for the first time. The most abundant protein in both matrices was the previously characterized spicule matrix protein SM50, but at least eight other members of this group, many of them only known as conceptual translation products previously, were identified by mass spectrometric sequence analysis of peptides derived from in vitro matrix degradation. The matrices also contained proteins implicated in biomineralization processes previously by inhibition studies using antibodies or specific enzyme inhibitors, such as matrix metalloproteases and members of the mesenchyme-specific MSP130 family. Other components were carbonic anhydrase, collagens, echinonectin, a α2-macroglobulin-like protein and several proteins containing scavenger receptor cysteine-rich domains. A few possible signal transduction pathway components, such as GTP-binding proteins, a semaphorin and a possible tyrosine kinase were also identified. Conclusion This report presents the most comprehensive

  5. Enhancement Effect of Sea Urchin Grow-out Cages in Lucero, Bolinao, Pangasinan

    Maria Celia Defrance Malay; Helen Grace Bangi; Marie Antonette Juinio-Meñez

    2000-01-01

    A preliminary study was conducted on the environmental impact of sea urchin (Tripneustes gratilla Linnaeas) grow-out culture in Lucero, Bolinao, Pangasinan. It was hypothesized that the feces generated by the caged urchins (~6,000 individuals at any one time) might cause localised sediment organic enrichment and subsequent shifts in benthic faunal communities. Results from preliminary surveys conducted in April and August of 1999 indicated minimal impact of sea urchin grow-out culture on the ...

  6. INHIBITING MAP KINASE ACTIVITY PREVENTS CALCIUM TRANSIENTS AND MITOSIS ENTRY IN EARLY SEA URCHIN EMBRYOS

    Philipova, Rada; Larman, Mark G.; Leckie, Calum P.; Harrison, Patrick K.; Groigno, Laurence; Whitaker, Michael

    2005-01-01

    A transient calcium increase triggers nuclear envelope breakdown (mitosis entry) in sea urchin embryos. Cdk1/cyclin B kinase activation is also known to be required for mitosis entry. More recently MAP kinase activity has also been shown to increase during mitosis. In sea urchin embryos both kinases show a similar activation profile, peaking at the time of mitosis entry.

  7. Predators of the destructive sea urchin Strongylocentrotus droebachiensis on the Norwegian coast

    Pedersen, Morten Foldager; Fagerli, Camilla With; Norderhaug, Kjell Magnus;

    2014-01-01

    most efficient sea urchin predator, and it was more abundant at kelp forest sites than on barren grounds. Stocks of C. pagurus have increased dramatically in central Norway since the 1990s, and predation by C. pagurus may contribute to the decline in sea urchin densities, allowing kelp recovery and...... conferring resilience of the new kelp forest state....

  8. Pigment cell differentiation in sea urchin blastula-derived primary cell cultures.

    Ageenko, Natalya V; Kiselev, Konstantin V; Dmitrenok, Pavel S; Odintsova, Nelly A

    2014-07-01

    The quinone pigments of sea urchins, specifically echinochrome and spinochromes, are known for their effective antioxidant, antibacterial, antifungal, and antitumor activities. We developed in vitro technology for inducing pigment differentiation in cell culture. The intensification of the pigment differentiation was accompanied by a simultaneous decrease in cell proliferation. The number of pigment cells was two-fold higher in the cells cultivated in the coelomic fluids of injured sea urchins than in those intact. The possible roles of the specific components of the coelomic fluids in the pigment differentiation process and the quantitative measurement of the production of naphthoquinone pigments during cultivation were examined by MALDI and electrospray ionization mass spectrometry. Echinochrome A and spinochrome E were produced by the cultivated cells of the sand dollar Scaphechinus mirabilis in all tested media, while only spinochromes were found in the cultivated cells of another sea urchin, Strongylocentrotus intermedius. The expression of genes associated with the induction of pigment differentiation was increased in cells cultivated in the presence of shikimic acid, a precursor of naphthoquinone pigments. Our results should contribute to the development of new techniques in marine biotechnology, including the generation of cell cultures producing complex bioactive compounds with therapeutic potential. PMID:24979272

  9. Pigment Cell Differentiation in Sea Urchin Blastula-Derived Primary Cell Cultures

    Natalya V. Ageenko

    2014-06-01

    Full Text Available The quinone pigments of sea urchins, specifically echinochrome and spinochromes, are known for their effective antioxidant, antibacterial, antifungal, and antitumor activities. We developed in vitro technology for inducing pigment differentiation in cell culture. The intensification of the pigment differentiation was accompanied by a simultaneous decrease in cell proliferation. The number of pigment cells was two-fold higher in the cells cultivated in the coelomic fluids of injured sea urchins than in those intact. The possible roles of the specific components of the coelomic fluids in the pigment differentiation process and the quantitative measurement of the production of naphthoquinone pigments during cultivation were examined by MALDI and electrospray ionization mass spectrometry. Echinochrome A and spinochrome E were produced by the cultivated cells of the sand dollar Scaphechinus mirabilis in all tested media, while only spinochromes were found in the cultivated cells of another sea urchin, Strongylocentrotus intermedius. The expression of genes associated with the induction of pigment differentiation was increased in cells cultivated in the presence of shikimic acid, a precursor of naphthoquinone pigments. Our results should contribute to the development of new techniques in marine biotechnology, including the generation of cell cultures producing complex bioactive compounds with therapeutic potential.

  10. The genome of the sea urchin Strongylocentrotus purpuratus.

    Sodergren, Erica; Weinstock, George M; Davidson, Eric H; Cameron, R Andrew; Gibbs, Richard A; Angerer, Robert C; Angerer, Lynne M; Arnone, Maria Ina; Burgess, David R; Burke, Robert D; Coffman, James A; Dean, Michael; Elphick, Maurice R; Ettensohn, Charles A; Foltz, Kathy R; Hamdoun, Amro; Hynes, Richard O; Klein, William H; Marzluff, William; McClay, David R; Morris, Robert L; Mushegian, Arcady; Rast, Jonathan P; Smith, L Courtney; Thorndyke, Michael C; Vacquier, Victor D; Wessel, Gary M; Wray, Greg; Zhang, Lan; Elsik, Christine G; Ermolaeva, Olga; Hlavina, Wratko; Hofmann, Gretchen; Kitts, Paul; Landrum, Melissa J; Mackey, Aaron J; Maglott, Donna; Panopoulou, Georgia; Poustka, Albert J; Pruitt, Kim; Sapojnikov, Victor; Song, Xingzhi; Souvorov, Alexandre; Solovyev, Victor; Wei, Zheng; Whittaker, Charles A; Worley, Kim; Durbin, K James; Shen, Yufeng; Fedrigo, Olivier; Garfield, David; Haygood, Ralph; Primus, Alexander; Satija, Rahul; Severson, Tonya; Gonzalez-Garay, Manuel L; Jackson, Andrew R; Milosavljevic, Aleksandar; Tong, Mark; Killian, Christopher E; Livingston, Brian T; Wilt, Fred H; Adams, Nikki; Bellé, Robert; Carbonneau, Seth; Cheung, Rocky; Cormier, Patrick; Cosson, Bertrand; Croce, Jenifer; Fernandez-Guerra, Antonio; Genevière, Anne-Marie; Goel, Manisha; Kelkar, Hemant; Morales, Julia; Mulner-Lorillon, Odile; Robertson, Anthony J; Goldstone, Jared V; Cole, Bryan; Epel, David; Gold, Bert; Hahn, Mark E; Howard-Ashby, Meredith; Scally, Mark; Stegeman, John J; Allgood, Erin L; Cool, Jonah; Judkins, Kyle M; McCafferty, Shawn S; Musante, Ashlan M; Obar, Robert A; Rawson, Amanda P; Rossetti, Blair J; Gibbons, Ian R; Hoffman, Matthew P; Leone, Andrew; Istrail, Sorin; Materna, Stefan C; Samanta, Manoj P; Stolc, Viktor; Tongprasit, Waraporn; Tu, Qiang; Bergeron, Karl-Frederik; Brandhorst, Bruce P; Whittle, James; Berney, Kevin; Bottjer, David J; Calestani, Cristina; Peterson, Kevin; Chow, Elly; Yuan, Qiu Autumn; Elhaik, Eran; Graur, Dan; Reese, Justin T; Bosdet, Ian; Heesun, Shin; Marra, Marco A; Schein, Jacqueline; Anderson, Michele K; Brockton, Virginia; Buckley, Katherine M; Cohen, Avis H; Fugmann, Sebastian D; Hibino, Taku; Loza-Coll, Mariano; Majeske, Audrey J; Messier, Cynthia; Nair, Sham V; Pancer, Zeev; Terwilliger, David P; Agca, Cavit; Arboleda, Enrique; Chen, Nansheng; Churcher, Allison M; Hallböök, F; Humphrey, Glen W; Idris, Mohammed M; Kiyama, Takae; Liang, Shuguang; Mellott, Dan; Mu, Xiuqian; Murray, Greg; Olinski, Robert P; Raible, Florian; Rowe, Matthew; Taylor, John S; Tessmar-Raible, Kristin; Wang, D; Wilson, Karen H; Yaguchi, Shunsuke; Gaasterland, Terry; Galindo, Blanca E; Gunaratne, Herath J; Juliano, Celina; Kinukawa, Masashi; Moy, Gary W; Neill, Anna T; Nomura, Mamoru; Raisch, Michael; Reade, Anna; Roux, Michelle M; Song, Jia L; Su, Yi-Hsien; Townley, Ian K; Voronina, Ekaterina; Wong, Julian L; Amore, Gabriele; Branno, Margherita; Brown, Euan R; Cavalieri, Vincenzo; Duboc, Véronique; Duloquin, Louise; Flytzanis, Constantin; Gache, Christian; Lapraz, François; Lepage, Thierry; Locascio, Annamaria; Martinez, Pedro; Matassi, Giorgio; Matranga, Valeria; Range, Ryan; Rizzo, Francesca; Röttinger, Eric; Beane, Wendy; Bradham, Cynthia; Byrum, Christine; Glenn, Tom; Hussain, Sofia; Manning, Gerard; Miranda, Esther; Thomason, Rebecca; Walton, Katherine; Wikramanayke, Athula; Wu, Shu-Yu; Xu, Ronghui; Brown, C Titus; Chen, Lili; Gray, Rachel F; Lee, Pei Yun; Nam, Jongmin; Oliveri, Paola; Smith, Joel; Muzny, Donna; Bell, Stephanie; Chacko, Joseph; Cree, Andrew; Curry, Stacey; Davis, Clay; Dinh, Huyen; Dugan-Rocha, Shannon; Fowler, Jerry; Gill, Rachel; Hamilton, Cerrissa; Hernandez, Judith; Hines, Sandra; Hume, Jennifer; Jackson, Laronda; Jolivet, Angela; Kovar, Christie; Lee, Sandra; Lewis, Lora; Miner, George; Morgan, Margaret; Nazareth, Lynne V; Okwuonu, Geoffrey; Parker, David; Pu, Ling-Ling; Thorn, Rachel; Wright, Rita

    2006-11-10

    We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes. PMID:17095691

  11. Sea Urchin Spines as a Model-System for Permeable, Light-Weight Ceramics with Graceful Failure Behavior. Part I. Mechanical Behavior of Sea Urchin Spines under Compression

    V. Presser; S. Schultheiβ; C. Berthold; K. G. Nickel

    2009-01-01

    The spines of pencil and lance urchins Heterocentrotus mammillatus and Phyllacanthus imperialis were studied as a model of light-weight material with high impact resistance. The complex and variable skeleton construction ("stereom") of body and spines of sea urchins consists of highly porous Mg-bearing calcium carbonate. This basically brittle material with pronounced single-crystal cleavage does not fracture by spontaneous catastrophic device failure but by graceful failure over the range of tens of millimeter of bulk compression instead. This was observed in bulk compression tests and blunt indentation experiments on regular, infiltrated and latex coated sea urchin spine segments. Microstructural characterization was carried out using X-ray computer tomography, optical and scanning electron microscopy. The behavior is interpreted to result from the hierarchic structure of sea urchin spines from the macroscale down to the nanoscale. Guidelines derived from this study see ceramics with layered porosity as a possible biomimetic construction for appropriate applications.

  12. Isolating specific embryonic cells of the sea urchin by FACS.

    Juliano, Celina; Swartz, S Zachary; Wessel, Gary

    2014-01-01

    Isolating cells based on specific gene expression enables a focused biochemical and molecular analysis. While cultured cells and hematopoietic cells, for example, are routinely isolated by fluorescence activated cell sorting (FACS), early embryonic cells are a relatively untapped source for FACS applications often because the embryos of many animals are quite limiting. Furthermore, many applications require genetic model organisms in which cells can be labeled by fluorescent transgenes, or antibodies against cell surface antigens. Here we define conditions in the sea urchin embryo for isolation of embryonic cells based on expression of specific proteins. We use the sea urchin embryo for which a nearly unlimited supply of embryonic cells is available and demonstrate the conditions for separation of the embryo into single cells, fixation of the cells for antibody penetration into the cells, and conditions for FACS of a rare cell type in the embryo. This protocol may be adapted for analysis of mRNA, chromatin, protein, or carbohydrates and depends only on the probe availability for the cell of interest. We anticipate that this protocol will be broadly applicable to embryos of other species. PMID:24567215

  13. [Morphology of gametes in sea urchins from Peter the Great Bay, Sea of Japan].

    Drozdov, A L; Vinnikova, V V

    2010-01-01

    The fine structure of the gametes in six sea urchin species of the Sea of Japan was studied. The spermatozoons in Strongylocentrotus nudus, S. intermedius, Echinocardium cordatum, Scaphechinus mirabilis, Sc. grizeus and Echinarachnius parma are species-specific. The conical head and symmetrically disposed ring-shape mitochondrion are common to regular sea urchin sperm cells. S. nudus is characterized by the bulb-shaped head of the zoosperm; S. intermedius, by a bullet-shaped one. The zoosperm spearhead and small amount of postacrosome material are common to irregular sea urchins; the sperm width: length ratio varies for different species, with the highest for Sc. mirabilis. The zoosperm of Sc. griseus is characterized by two lipid drops in the cell center. Asymmetrical mitochondrion disposal is usual for E. parma. Actin filaments are found in the postacrosome material in the zoosperm of cordiform sea urchins. The differences in the fine structure of zoosperm in eurybiont species Ech. cordatum inhabiting the Sea of Japan and coastal areas of the Northeast Atlantic may bear record to the complex existence of species Ech. cordatum. The fine structure of zoosperm is unique for each of the studied families, Strongylocentrotidae, Scutellidae, and Loveniidae. The eggs of all the species are characterized by vitelline and tremelloid membranes. The vitelline membrane is formed by cytoplasm protrusions; the area between them is filled with fubrillary material. The tremelloid membrane is formed by fubrillary material associated with apical parts of microvilli of the vitelline membrane. The irregular sea urchins Sc. griseus, Sc. mirabilis and E. parma are characterized by chromatophores situated in the tremelloid membrane, with the highest abundance in Sc. mirabilis. PMID:20184121

  14. Effects of gravity on spicule formation in cultured micromeres of sea urchin embryo

    Izumi-Kurotani, A.; Kiyomoto, M.; Imai, M.; Eguchi, H.

    2006-01-01

    To investigate the effects of gravity on morphogenesis at the cellular level, we have proposed a new experimental system with micromeres from sea urchin embryos [Izumi-Kurotani, A., Kiyomoto, M. Morphogenesis and gravity in a whole Amphibian Embryo and in isolated blastomeres of sea urchins, in: Marthy, H. -J. (Ed.), Developmental Biology Research in Space. Adv. Space Biol. Med. vol. 9, Elsevier, Amsterdam, pp. 83 99, 2003]. We studied spicule formation in cultured micromeres of sea urchin embryo under various conditions of gravity: hypergravity by a centrifuge and simulated microgravity in a vertical clinostat. Spicule elongation was suppressed under both experimental conditions.

  15. Accumulation of 95mTc by marine algae and sea urchin

    It is necessary to investigate the accumulation of technetium by marine algae popular in Japan and it is also important to examine the contribution of food to the accumulation of the nuclide by sea urchin which grazes algae. In the laboratory tracer experiment, some species of algae and sea urchin were kept separately for 7 days in sea water containing 95mTc (uptake experiment) and then transferred into non-radioactive sea water to be held for 28 days with the frequent renewal of the sea water (excretion experiment). No food was given during the uptake experiment to prevent the urchins from accumulating 95mTc through food. Another experiment was done by feeding urchins with 95mTc labeled algae in the non-radioactive sea water. Five species of brown algae showed CFs in the range of 900 and 35000 but CFs of green and red algae were 1-4. Sea urchin accumulated more 95mTc through food (brown algae) than directly from sea water, so that the main pathway of technetium accumulation by sea urchin was estimated to be brown algae which were the most favorite food of the organism. (author)

  16. Acetylcholine synthesis and possible functions during sea urchin development

    C Angelini

    2009-06-01

    Full Text Available Cholinergic neurotransmitter system molecules were found to play a role during fertilisation and early cell cycles of a large number of invertebrate and vertebrate organisms. In this study, we investigated the presence and possible function of choline acetyltransferase (ChAT, the biosynthetic enzyme of acetylcholine in gametes of the sea urchin, Paracentrotus lividus, through localisation and functional studies. ChAT-like molecules were detected in oocytes, mature eggs and zygotes with indirect immunofluorescence methods. Positive immunoreactivity was found in the ovarian egg cytoplasm and surface as well as at the zygote surface. This suggests the eggs' capacity to autonomously synthesise acetylcholine (ACh, the signal molecule of the cholinergic system. Acetylcholinesterase (AChE, the lytic enzyme of acetylcholine was also found in ovarian eggs, with a similar distribution; however, it disappeared after fertilisation. Ultrastructural ChAT localisation in sperms, which was carried out with the immuno-gold method, showed immunoreactivity in the acrosome of unreacted sperms and at the head surface of reacted sperms. In order to verify a functional role of ACh during fertilization and sea urchin development, in vivo experiments were performed. Exposure of the eggs before fertilisation to 1 mM ACh + 1 ?M eserine caused an incomplete membrane depolarisation and consequently enhanced polyspermy, while lower concentrations of ACh caused developmental anomalies. The exposure of zygotes to 0,045 AChE Units/mL of sea water caused developmental anomalies as well, in 50% of the embryos. Altogether, these findings and other previously obtained results, suggest that the cholinergic system may subserve two different tasks during development, according to which particular type of ACh receptor is active during each temporal window. The first function, taking place in the course of fertilisation is a result of autonomously synthesised ACh in sperms, while the

  17. Kelp Forests versus Urchin Barrens: Alternate Stable States and Their Effect on Sea Otter Prey Quality in the Aleutian Islands

    Nathan L. Stewart

    2012-01-01

    Full Text Available Macroalgal and urchin barren communities are alternately stable and persist in the Aleutians due to sea otter presence and absence. In the early 1990s a rapid otter population decline released urchins from predation and caused a shift to the urchin-dominated state. Despite increases in urchin abundance, otter numbers continued to decline. Although debated, prey quality changes have been implicated in current otter population status. This study examined otter prey abundance, size, biomass, and potential energy density in remnant kelp forest and urchin-dominated communities to determine if alternate stable states affect prey quality. Findings suggest that although urchin barrens provide more abundant urchin prey, individual urchins are smaller and provide lower biomass and potential energy density compared to kelp forests. Shifts to urchin barrens do affect prey quality but changes are likely compensated by increased prey densities and are insufficient in explaining current otter population status in the Aleutians.

  18. Development of an underwater high sensitivity Cherenkov detector: Sea Urchin

    The need for a high gain, high sensitivity Cherenkov light sensor to be used in a deep underwater muon and neutrino detector (DUMAND) array has led to the design of the Sea Urchin detector. In this design a spherical photocathode PMTis optically coupled through a glass hemisphere to a large number of glass spines, each of which is filled with a wavelength-shifting (WLS) solution of a high quantum efficiency phosphor. The Cherenkov radiation is absorbed in the spine, isotropically re-radiated at a longer wavelength, and a fraction of the fluorescent light is internally reflected in the spine, and guided to the photomultiplier concentrically located in the glass hemisphere. Experiments measuring the optical characteristics of the spines and computer programs simulating light transformation and detection cross sections are described. Overall optical gains in the range 5-10 are achieved. The WLS solution is inexpensive, and may have other applications. (orig.)

  19. Expression of Pigment Cell-Specific Genes in the Ontogenesis of the Sea Urchin Strongylocentrotus intermedius

    Natalya V. Ageenko; Konstantin V. Kiselev; Odintsova, Nelly A.

    2011-01-01

    One of the polyketide compounds, the naphthoquinone pigment echinochrome, is synthesized in sea urchin pigment cells. We analyzed polyketide synthase (pks) and sulfotransferase (sult) gene expression in embryos and larvae of the sea urchin Strongylocentrotus intermedius from various stages of development and in specific tissues of the adults. We observed the highest level of expression of the pks and sult genes at the gastrula stage. In unfertilized eggs, only trace amounts of the pks and sul...

  20. Pigment Cell Differentiation in Sea Urchin Blastula-Derived Primary Cell Cultures

    Natalya V. Ageenko; Konstantin V. Kiselev; Dmitrenok, Pavel S.; Odintsova, Nelly A.

    2014-01-01

    The quinone pigments of sea urchins, specifically echinochrome and spinochromes, are known for their effective antioxidant, antibacterial, antifungal, and antitumor activities. We developed in vitro technology for inducing pigment differentiation in cell culture. The intensification of the pigment differentiation was accompanied by a simultaneous decrease in cell proliferation. The number of pigment cells was two-fold higher in the cells cultivated in the coelomic fluids of injured sea urchin...

  1. Stated Preferences for Consumption of Sea Urchin: A Choice Experiment in Sardinia (Italy

    Roberto Furesi

    2014-10-01

    Full Text Available In Sardinia sea urchin (Paracentrotus lividus roe is a basic ingredient for several dishes (e.g. pasta, pizza, croutons and its demand is constantly increasing. However marketable value of local sea urchin appears to be potentially higher than the current value. This paper aims to estimate the value of a based sea urchin dish according to the stated preference of consumers. A Choice Experiment (CE analysis on 475 consumers was carried out in order to estimate their willingness to pay (WTP for consuming sea urchin. Seafood was proposed as alternative to sea urchin. CE concerned two attributes:certification of local origin and place where dishes are consumed. Findings suggest that WTP for a generic dish is significantly higher for sea urchin (11.65 Euros than for seafood (7.94 Euros based dish. Furthermore, we found that WTP is higher when both foods are consumed with spaghetti and as raw fresh product, whereas an opposite effect is associated to pizza. Finally, the influence of some socio‐economic characteristics of responders on their preferences was estimated.

  2. Experimental evidence that intra-specific competition in seagrass meadows reduces reproductive potential in the sea urchin Paracentrotus lividus (Lamarck)

    Tomàs Nash, Fiona; Romero, Javier; Turon Barrera, Xavier

    2005-01-01

    To better understand the biological controls that regulate sea urchin dynamics, we studied the effects of potential inter- and intra-specific competition for food on several biological variables of the main sea urchin in the Mediterranean (Paracentrotus lividus). We carried out a caging experiment in which we manipulated sea urchin density (natural vs. high density) and herbivorous fish (Sarpa salpa) accessibility (free access vs. exclusion) in a Posidonia oceanica meadow. No evidence of comp...

  3. Isolation and structural studies of a sulfated sialosphingolipid from the sea urchin Echinocardium cordatum.

    Kochetkov, N K; Smirnova, G P; Chekareva, N V

    1976-02-23

    Three sialosphingolipids have been isolated from a lipid extract of gonads of the sea urchin Echinocardium cordatum by partition dialysis and DEAE-cellulose column chromatography. The structure of the sialosphingolipid containing sulfate group has been established. On the basis of the results of total and partial acid hydrolysis, methanolysis, methylation, periodate oxidation and enzymatic hydrolysis with neuraminidase the sulfated sialosphingolipid was identified as 8-sulfate-sialyl-alpha-(2 leads to 6)glucopyranosyl-(1 leads to 1)ceramide. The long-chain bases were mainly phytosphingosine and its C16 homologue. The fatty acids of the sialosphingolipid were the mixture of normal and alpha-hydroxy fatty acids, their compositions were analysed by gas-liquid chromatography. PMID:1252492

  4. First insights into the biochemistry of tube foot adhesive from the sea urchin Paracentrotus lividus (Echinoidea, Echinodermata).

    Santos, R; da Costa, G; Franco, C; Gomes-Alves, P; Flammang, P; Coelho, A V

    2009-01-01

    Sea urchins are common inhabitants of wave-swept shores. To withstand the action of waves, they rely on highly specialized independent adhesive organs, the adoral tube feet. The latter are extremely well-designed for temporary adhesion being composed by two functional subunits: (1) an apical disc that produces an adhesive secretion to fasten the sea urchin to the substratum, as well as a deadhesive secretion to allow the animal to move and (2) a stem that bears the tensions placed on the animal by hydrodynamism. Despite their technological potential for the development of new biomimetic underwater adhesives, very little is known about the biochemical composition of sea urchin adhesives. A characterization of sea urchin adhesives is presented using footprints. The latter contain inorganic residues (45.5%), proteins (6.4%), neutral sugars (1.2%), and lipids (2.5%). Moreover, the amino acid composition of the soluble protein fraction revealed a bias toward six amino acids: glycine, alanine, valine, serine, threonine, and asparagine/aspartic acid, which comprise 56.8% of the total residues. In addition, it also presents higher levels of proline (6.8%) and half-cystine (2.6%) than average eukaryotic proteins. Footprint insolubility was partially overcome using strong denaturing and reducing buffers, enabling the visualization of 13 proteins by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The conjugation of mass spectrometry with homology-database search allowed the identification of six proteins: alpha and beta tubulin, actin, and histones H2B, H3, H2A, and H4, whose location and function in the adhesive are discussed but require further investigation. For the remaining unidentified proteins, five de novo-generated peptide sequences were found that were not present in the available protein databases, suggesting that they might be novel or modified proteins. PMID:19221839

  5. Hsp70 as a stress marker of sea urchin coelomocytes in short term cultures.

    Matranga, Valeria; Bonaventura, Rosa; Di Bella, Gloria

    2002-06-01

    Coelomocytes are the immune effectors of the sea urchin and have shown to respond to environmental and experimental challenge by the activation of stress markers. We extended our in vivo studies to in vitro short term cultures of sea urchin coelomocytes by analysing their response to temperature being stress, acid pH and heavy metals, using the hsp70 protein as a stress marker. We found that the in vitro time course of temperature stress recapitulates results obtained in vivo where the highest overexpression was observed after 1 hour. Coelomocytes overexpress hsp70 in a time-dependent manner when cultured for 1 to 6 hr at pH 4.7 +/- 0.2 in isotonic buffer, supplemented with EDTA as anticoagulant. A peak in the level of hsp70 expression was observed at 2 hr of culture, corresponding to a 10-fold increase over the levels of control coelomocytes cultured at pH 7.3 +/- 0.2. The effect of different concentrations of CdCl2 in the culture over a period of 4 hr was also tested. We found that CdCl2 greatly increases the hsp70 expression, with 10(-3) M the dose at which the highest overexpression is observed. PMID:12064441

  6. Triphenylphosphonium Cations of the Diterpenoid Isosteviol: Synthesis and Antimitotic Activity in a Sea Urchin Embryo Model.

    Strobykina, Irina Yu; Belenok, Mayya G; Semenova, Marina N; Semenov, Victor V; Babaev, Vasiliy M; Rizvanov, Ildar Kh; Mironov, Vladimir F; Kataev, Vladimir E

    2015-06-26

    A series of novel triphenylphosphonium (TPP) cations of the diterpenoid isosteviol (1, 16-oxo-ent-beyeran-19-oic acid) have been synthesized and evaluated in an in vivo phenotypic sea urchin embryo assay for antimitotic activity. The TPP moiety was applied as a carrier to provide selective accumulation of a connected compound into mitochondria. When applied to fertilized eggs, the targeted isosteviol TPP conjugates induced mitotic arrest with the formation of aberrant multipolar mitotic spindles, whereas both isosteviol and the methyltriphenylphosphonium cation were inactive. The structure-activity relationship study revealed the essential role of the TPP group for the realization of the isosteviol effect, while the chemical structure and the length of the linker only slightly influenced the antimitotic potency. The results obtained using the sea urchin embryo model suggested that TPP conjugates of isosteviol induced mitotic spindle defects and mitotic arrest presumably by affecting mitochondrial DNA. Since targeting mitochondria is considered as an encouraging strategy for cancer therapy, TPP-isosteviol conjugates may represent promising candidates for further design as anticancer agents. PMID:26042548

  7. Sperm chemotaxis promotes individual fertilization success in sea urchins.

    Hussain, Yasmeen H; Guasto, Jeffrey S; Zimmer, Richard K; Stocker, Roman; Riffell, Jeffrey A

    2016-05-15

    Reproductive success fundamentally shapes an organism's ecology and evolution, and gamete traits mediate fertilization, which is a critical juncture in reproduction. Individual male fertilization success is dependent on the ability of sperm from one male to outcompete the sperm of other males when searching for a conspecific egg. Sperm chemotaxis, the ability of sperm to navigate towards eggs using chemical signals, has been studied for over a century, but such studies have long assumed that this phenomenon improves individual male fitness without explicit evidence to support this claim. Here, we assessed fertilization changes in the presence of a chemoattractant-digesting peptidase and used a microfluidic device coupled with a fertilization assay to determine the effect of sperm chemotaxis on individual male fertilization success in the sea urchin Lytechinus pictus We show that removing chemoattractant from the gametic environment decreases fertilization success. We further found that individual male differences in chemotaxis to a well-defined gradient of attractant correlate with individual male differences in fertilization success. These results demonstrate that sperm chemotaxis is an important contributor to individual reproductive success. PMID:26994183

  8. Gal4-gene-dependent alterations of embryo development and cell growth in primary culture of sea urchins.

    Bulgakov, V P; Odintsova, N A; Plotnikov, S V; Kiselev, K V; Zacharov, E V; Zhuravlev, Y N

    2002-10-01

    Primary cell cultures from sea urchins have a low proliferative level that prevents the establishment of long-term cultures. To increase expression levels of the genes regulating cell growth in sea urchins, and thus enhance cell growth, we used the transcriptional activator gene Gal4 found earlier in yeast. Sea urchin embryos were treated with plasmid DNA containing the Gal4 gene. Expression of the transgene was confirmed by reverse transcriptase polymerase chain reaction. When the fully functional gene was used, embryos effectively formed teratoma-like structures after 50 to 55 hours of cultivation. In contrast, the Gal4 gene, devoid of acidic activating regions, possessed little activity as a teratogen. The Gal4-treated cells in blastula-derived culture showed higher DNA synthesis and higher proliferative activity than control cells. We suggest that formation of the teratoma-like structures in embryos, activation of DNA synthesis, and significant increase of cell number in embryo-derived cell cultures could be attributed to Gal4 gene action. PMID:14961241

  9. Diatom-derived oxylipins induce cell death in sea urchin embryos activating caspase-8 and caspase 3/7.

    Ruocco, Nadia; Varrella, Stefano; Romano, Giovanna; Ianora, Adrianna; Bentley, Matt G; Somma, Domenico; Leonardi, Antonio; Mellone, Stefano; Zuppa, Antonio; Costantini, Maria

    2016-07-01

    Diatoms are an important class of unicellular algae that produce bioactive secondary metabolites with cytotoxic activity collectively termed oxylipins, including polyunsaturated aldehydes (PUAs), hydroxyacids (HEPEs), oxo-acids and epoxyalcohols. Previous results showed that at higher concentrations, the PUA decadienal induced apoptosis on copepods and sea urchin embryos via caspase-3 activation; at lower concentrations decadienal affected the expression levels of the caspase-8 gene in embryos of the sea urchin Paracentrotus lividus. In the present work, we studied the effects of other common oxylipins produced by diatoms: two PUAs (heptadienal and octadienal) and four hydroxyacids (5-, 9- 11- and 15-HEPE) on P. lividus cell death and caspase activities. Our results showed that (i) at higher concentrations PUAs and HEPEs induced apoptosis in sea urchin embryos, detected by microscopic observation and through the activation of caspase-3/7 and caspase-8 measured by luminescent assays; (ii) at low concentrations, PUAs and HEPEs affected the expression levels of caspase-8 and caspase-3/7 (isolated for the first time here in P. lividus) genes, detected by Real Time qPCR. These findings have interesting implications from the ecological point of view, given the importance of diatom blooms in nutrient-rich aquatic environments. PMID:27130972

  10. Enhancement Effect of Sea Urchin Grow-out Cages in Lucero, Bolinao, Pangasinan

    Maria Celia Defrance Malay

    2000-12-01

    Full Text Available A preliminary study was conducted on the environmental impact of sea urchin (Tripneustes gratilla Linnaeas grow-out culture in Lucero, Bolinao, Pangasinan. It was hypothesized that the feces generated by the caged urchins (~6,000 individuals at any one time might cause localised sediment organic enrichment and subsequent shifts in benthic faunal communities. Results from preliminary surveys conducted in April and August of 1999 indicated minimal impact of sea urchin grow-out culture on the local reef flat community. Some enhancement of faunal abundance and sediment organic matter content in the cage area were noted; however, the impact was limited to a radius of 5-25 meters from the grow-out cages. The enhancement effects appeared to be seasonal occurrences that were dependent on local currents and degree of wave exposure. Epiphyte biomass, total suspended solids, sediment grain size, and relative water movement seemed largely unaffected by sea urchin grow-out culture. However, more frequent and thorough samplings are needed to validate these initial results. The presence of localised enrichment in sediment organic content and epibenthic faunal density suggest the possibility of converting the sea urchin grow-out area into polyculture systems that would make more efficient use of the food resources available while minimizing potential anthropogenic impacts on the environment.

  11. Revision of new species of Eocene sea urchins from Istria, described in the 19th and 20th centuries

    Vasja Mikuž

    2008-06-01

    Full Text Available In paper are presented drawings and pictures of sea urchins from original works of authors who determined and documented new species from Istria. TARAMELLI (1874, BITTNER (1880, OPPENHEIM (1901, TONIOLO (1909 and DEGLI INNOCENTI (1924 a, b established in Paleogene beds of Istria 18 new species of Eocene sea urchins. Determined were four species of regular sea urchins of genera Stereocidaris, Phyllacanthus, “Eucidaris” and Arachniopleurus,and fourteen species of irregular sea urchins of nine genera - Conoclypus, Echinolampas, Rhyncholampas,Gitolampas, Ditremaster, Pericosmus, Prenaster, Brissopsis and Cyclaster. The highest species diversity was recorded within genus Echinolampas. New sea urchins species originate prevailingly in the Middle Eocene – Lutetian beds of localities in the narrower and broader surroundings of Koper, Buzet, Roč, Grdoselo, Pazin, Pićan, Ćepić and Labin.

  12. The contribution of apoptosis and necrosis in freezing injury of sea urchin embryonic cells.

    Boroda, Andrey V; Kipryushina, Yulia O; Yakovlev, Konstantin V; Odintsova, Nelly A

    2016-08-01

    Sea urchins have recently been reported to be a promising tool for investigations of oxidative stress, UV light perturbations and senescence. However, few available data describe the pathway of cell death that occurs in sea urchin embryonic cells after cryopreservation. Our study is focused on the morphological and functional alterations that occur in cells of these animals during the induction of different cell death pathways in response to cold injury. To estimate the effect of cryopreservation on sea urchin cell cultures and identify the involved cell death pathways, we analyzed cell viability (via trypan blue exclusion test, MTT assay and DAPI staining), caspase activity (via flow cytometry and spectrophotometry), the level of apoptosis (via annexin V-FITC staining), and cell ultrastructure alterations (via transmission electron microscopy). Using general caspase detection, we found that the level of caspase activity was low in unfrozen control cells, whereas the number of apoptotic cells with activated caspases rose after freezing-thawing depending on cryoprotectants used, also as the number of dead cells and cells in a late apoptosis. The data using annexin V-binding assay revealed a very high apoptosis level in all tested samples, even in unfrozen cells (about 66%). Thus, annexin V assay appears to be unsuitable for sea urchin embryonic cells. Typical necrotic cells with damaged mitochondria were not detected after freezing in sea urchin cell cultures. Our results assume that physical cell disruption but not freezing-induced apoptosis or necrosis is the predominant reason of cell death in sea urchin cultures after freezing-thawing with any cryoprotectant combination. PMID:27364314

  13. A carbohydrate-based mechanism of species recognition in sea urchin fertilization

    P.A.S. Mourão

    2007-01-01

    Full Text Available In the present review, we describe a systematic study of the sulfated polysaccharides from marine invertebrates, which led to the discovery of a carbohydrate-based mechanism of sperm-egg recognition during sea urchin fertilization. We have described unique polymers present in these organisms, especially sulfated fucose-rich compounds found in the egg jelly coat of sea urchins. The polysaccharides have simple, linear structures consisting of repeating units of oligosaccharides. They differ among the various species of sea urchins in specific patterns of sulfation and/or position of the glycosidic linkage within their repeating units. These polysaccharides show species specificity in inducing the acrosome reaction in sea urchin sperm, providing a clear-cut example of a signal transduction event regulated by sulfated polysaccharides. This distinct carbohydrate-mediated mechanism of sperm-egg recognition coexists with the bindin-protein system. Possibly, the genes involved in the biosynthesis of these sulfated fucans did not evolve in concordance with evolutionary distance but underwent a dramatic change near the tip of the Strongylocentrotid tree. Overall, we established a direct causal link between the molecular structure of a sulfated polysaccharide and a cellular physiological event - the induction of the sperm acrosome reaction in sea urchins. Small structural changes modulate an entire system of sperm-egg recognition and species-specific fertilization in sea urchins. We demonstrated that sulfated polysaccharides - in addition to their known function in cell proliferation, development, coagulation, and viral infection - mediate fertilization, and respond to evolutionary mechanisms that lead to species diversity.

  14. Cyclic GMP-specific Phosphodiesterase-5 Regulates Motility of Sea Urchin Spermatozoa

    Su, Yi-Hsien; Vacquier, Victor D.

    2006-01-01

    Motility, chemotaxis, and the acrosome reaction of animal sperm are all regulated by cyclic nucleotides and protein phosphorylation. One of the cyclic AMP-dependent protein kinase (PKA) substrates in sea urchin sperm is a member of the phosphodiesterase (PDE) family. The molecular identity and in vivo function of this PDE remained unknown. Here we cloned and characterized this sea urchin sperm PDE (suPDE5), which is an ortholog of human PDE5. The recombinant catalytic domain of suPDE5 hydroly...

  15. Pattern formation during gastrulation in the sea urchin embryo.

    McClay, D R; Armstrong, N A; Hardin, J

    1992-01-01

    The sea urchin embryo follows a relatively simple cell behavioral sequence in its gastrulation movements. To form the mesoderm, primary mesenchyme cells ingress from the vegetal plate and then migrate along the basal lamina lining the blastocoel. The presumptive secondary mesenchyme and endoderm then invaginate from the vegetal pole of the embryo. The archenteron elongates and extends across the blastocoel until the tip of the archenteron touches and attaches to the opposite side of the blastocoel. Secondary mesenchyme cells, originally at the tip of the archenteron, differentiate to form a variety of structures including coelomic pouches, esophageal muscles, pigment cells and other cell types. After migration of the secondary mesenchyme cells from their original position at the tip of the archenteron, the endoderm fuses with an invagination of the ventral ectoderm (the stomodaem), to form the mouth and complete the process of gastrulation. A larval skeleton is made by primary mesenchyme cells during the time of archenteron and mouth formation. A number of experiments have established that these morphogenetic movements involve a number of cell autonomous behaviors plus a series of cell interactions that provide spatial, temporal and scalar information to cells of the mesoderm and endoderm. The cell autonomous behaviors can be demonstrated by the ability of micromeres or endoderm to perform their morphogenetic functions if either is isolated and grown in culture. The requirement for cell interactions has been demonstrated by manipulative experiments where it has been shown that axial information, temporal information, spatial information and scalar information is obtained by mesoderm and endoderm from other embryonic cells.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1299366

  16. Contrasting recruitment seasonality of sea urchin species in Gran Canaria, Canary Islands (eastern Atlantic

    S. GARCIA-SANZ

    2014-09-01

    Full Text Available Despite sea-urchins can play an important role affecting the community structure of subtidal bottoms, factors controlling the dynamics of sea-urchin populations are still poorly understood. We assessed the seasonal variation in recruitment of three sea-urchin species (Diadema africanum, Paracentrotus lividus and Arbacia lixula at Gran Canaria Island (eastern Atlantic via monthly deployment of artificial collectors throughout an entire annual cycle on each of four adjacent habitat patches (seagrasses, sandy patches, ‘urchin-grazed’ barrens and macroalgal-dominated beds within a shallow coastal landscape. Paracentrotus lividus and A. lixula had exclusively one main recruitment peak in late winter-spring. Diadema africanum recruitment was also seasonal, but recruits appeared in late summer-autumn, particularly on ‘urchin-grazed’ barrens with large abundances of adult conspecifics. In conclusion, this study has demonstrated non-overlapping seasonal recruitment patterns of the less abundant species (P. lividus and A. lixula with the most conspicuous species (D. africanum in the study area.

  17. In-depth, high-accuracy proteomics of sea urchin tooth organic matrix

    Mann Matthias

    2008-12-01

    Full Text Available Abstract Background The organic matrix contained in biominerals plays an important role in regulating mineralization and in determining biomineral properties. However, most components of biomineral matrices remain unknown at present. In sea urchin tooth, which is an important model for developmental biology and biomineralization, only few matrix components have been identified. The recent publication of the Strongylocentrotus purpuratus genome sequence rendered possible not only the identification of genes potentially coding for matrix proteins, but also the direct identification of proteins contained in matrices of skeletal elements by in-depth, high-accuracy proteomic analysis. Results We identified 138 proteins in the matrix of tooth powder. Only 56 of these proteins were previously identified in the matrices of test (shell and spine. Among the novel components was an interesting group of five proteins containing alanine- and proline-rich neutral or basic motifs separated by acidic glycine-rich motifs. In addition, four of the five proteins contained either one or two predicted Kazal protease inhibitor domains. The major components of tooth matrix were however largely identical to the set of spicule matrix proteins and MSP130-related proteins identified in test (shell and spine matrix. Comparison of the matrices of crushed teeth to intact teeth revealed a marked dilution of known intracrystalline matrix proteins and a concomitant increase in some intracellular proteins. Conclusion This report presents the most comprehensive list of sea urchin tooth matrix proteins available at present. The complex mixture of proteins identified may reflect many different aspects of the mineralization process. A comparison between intact tooth matrix, presumably containing odontoblast remnants, and crushed tooth matrix served to differentiate between matrix components and possible contributions of cellular remnants. Because LC-MS/MS-based methods directly

  18. Photoquadrat Analysis of how Sea Urchins Reduce Abundance of Kappaphycus and Analysis of Regrowth of Coral on Plots in Kaneohe Bay, Oahu, Hawaii in 2002 (NODC Accession 0001022)

    National Oceanic and Atmospheric Administration, Department of Commerce — An experiment was performed to assess the potential to use native sea urchins as biocontrols for alien/invasive seaweeds. One species of urchin, tripneustes...

  19. Photoquadrat analysis of how sea urchins reduce abundance of Kappaphycus and analysis of regrowth of coral on plots in Kaneohe Bay, Oahu, Hawaii in 2002 (NODC Accession 0001022)

    National Oceanic and Atmospheric Administration, Department of Commerce — An experiment was performed to assess the potential to use native sea urchins as biocontrols for alien/invasive seaweeds. One species of urchin, tripneustes...

  20. Solvothermal synthesis and high optical performance of three-dimensional sea-urchin-like TiO2

    Graphical abstract: I–V characteristics of different TiO2 microspheres based DSSCs (a) 3D sphere-like, (b) 3D flower-like, (c) 3D sea-urchin-like. - Highlights: • 3D sea-urchin-like TiO2 was synthesized by solvothermal method. • The effects of preparation parameters on the microstructure of the microspheres were investigated. • The photoelectric properties of 3D sea-urchin-like TiO2 were studied upon DSSCs. • The PCE of the 3D sea-urchin-like TiO2 was higher than that of other morphologies. - Abstract: Three-dimensional (3D) sea-urchin-like TiO2 microspheres were successfully synthesised by solvothermal method. The effects of preparation parameters including reaction temperature, concentration and mass fraction of precursor, and solvent volume on the microstructure of the microspheres were investigated. Results of scanning electron microscopy showed that the preparation parameters played a critical role in the morphology of 3D sea-urchin-like TiO2. In addition, when the sea-urchin-like TiO2 nanostructures were used as the dye-sensitized solar cells (DSSCs) anode, the power-conversion efficiency was higher than that of other morphologies, which was due to the special 3D hierarchical nanostructure, large specific surface area, and enhanced absorption of UV–vis of the TiO2 nanostructures

  1. Solvothermal synthesis and high optical performance of three-dimensional sea-urchin-like TiO{sub 2}

    Zhou, Yi, E-mail: zhouyihn@163.com; Wang, Yutang; Li, Mengyao; Li, Xuzhi; Yi, Qin; Deng, Pan; Wu, Hongyan

    2015-06-15

    Graphical abstract: I–V characteristics of different TiO{sub 2} microspheres based DSSCs (a) 3D sphere-like, (b) 3D flower-like, (c) 3D sea-urchin-like. - Highlights: • 3D sea-urchin-like TiO{sub 2} was synthesized by solvothermal method. • The effects of preparation parameters on the microstructure of the microspheres were investigated. • The photoelectric properties of 3D sea-urchin-like TiO{sub 2} were studied upon DSSCs. • The PCE of the 3D sea-urchin-like TiO{sub 2} was higher than that of other morphologies. - Abstract: Three-dimensional (3D) sea-urchin-like TiO{sub 2} microspheres were successfully synthesised by solvothermal method. The effects of preparation parameters including reaction temperature, concentration and mass fraction of precursor, and solvent volume on the microstructure of the microspheres were investigated. Results of scanning electron microscopy showed that the preparation parameters played a critical role in the morphology of 3D sea-urchin-like TiO{sub 2}. In addition, when the sea-urchin-like TiO{sub 2} nanostructures were used as the dye-sensitized solar cells (DSSCs) anode, the power-conversion efficiency was higher than that of other morphologies, which was due to the special 3D hierarchical nanostructure, large specific surface area, and enhanced absorption of UV–vis of the TiO{sub 2} nanostructures.

  2. Involvement of l(-)-rhamnose in sea urchin gastrulation. Part II: α-l-Rhamnosidase.

    Liang, Jing; Aleksanyan, Heghush; Metzenberg, Stan; Oppenheimer, Steven B

    2016-06-01

    The sea urchin embryo is recognized as a model system to reveal developmental mechanisms involved in human health and disease. In Part I of this series, six carbohydrates were tested for their effects on gastrulation in embryos of the sea urchin Lytechinus pictus. Only l-rhamnose caused dramatic increases in the numbers of unattached archenterons and exogastrulated archenterons in living, swimming embryos. It was found that at 30 h post-fertilization the l-rhamnose had an unusual inverse dose-dependent effect, with low concentrations (1-3 mM) interfering with development and higher concentrations (30 mM) having little to no effect on normal development. In this study, embryos were examined for inhibition of archenteron development after treatment with α-l-rhamnosidase, an endoglycosidase that removes terminal l-rhamnose sugars from glycans. It was observed that the enzyme had profound effects on gastrulation, an effect that could be suppressed by addition of l-rhamnose as a competitive inhibitor. The involvement of l-rhamnose-containing glycans in sea urchin gastrulation was unexpected, since there are no characterized biosynthetic pathways for rhamnose utilization in animals. It is possible there exists a novel l-rhamnose-containing glycan in sea urchins, or that the enzyme and sugar interfere with the function of rhamnose-binding lectins, which are components of the innate immune system in many vertebrate and invertebrate species. PMID:26168775

  3. Functional diversification of sea urchin ABCC1 (MRP1) by alternative splicing.

    Gökirmak, Tufan; Campanale, Joseph P; Reitzel, Adam M; Shipp, Lauren E; Moy, Gary W; Hamdoun, Amro

    2016-06-01

    The multidrug resistance protein (MRP) family encodes a diverse repertoire of ATP-binding cassette (ABC) transporters with multiple roles in development, disease, and homeostasis. Understanding MRP evolution is central to unraveling their roles in these diverse processes. Sea urchins occupy an important phylogenetic position for understanding the evolution of vertebrate proteins and have been an important invertebrate model system for study of ABC transporters. We used phylogenetic analyses to examine the evolution of MRP transporters and functional approaches to identify functional forms of sea urchin MRP1 (also known as SpABCC1). SpABCC1, the only MRP homolog in sea urchins, is co-orthologous to human MRP1, MRP3, and MRP6 (ABCC1, ABCC3, and ABCC6) transporters. However, efflux assays revealed that alternative splicing of exon 22, a region critical for substrate interactions, could diversify functions of sea urchin MRP1. Phylogenetic comparisons also indicate that while MRP1, MRP3, and MRP6 transporters potentially arose from a single transporter in basal deuterostomes, alternative splicing appears to have been the major mode of functional diversification in invertebrates, while duplication may have served a more important role in vertebrates. These results provide a deeper understanding of the evolutionary origins of MRP transporters and the potential mechanisms used to diversify their functions in different groups of animals. PMID:27053522

  4. Monodictyquinone A: a new antimicrobial anthraquinone from a sea urchin-derived fungus Monodictys sp.

    El-Beih, Ahmed Atef; Kawabata, Tetsuro; Koimaru, Keiichiro; Ohta, Tomihisa; Tsukamoto, Sachiko

    2007-07-01

    A new antimicrobial anthraquinone, 1,8-dihydroxy-2-methoxy-6-methylanthraquinone, monodictyquinone A (1), was isolated from a culture of a marine-derived fungus of the genus Monodictys which was isolated from the sea urchin, Anthocidaris crassispina, along with three known compounds, pachybasin (2), chrysophanol (3), and emodin (4). PMID:17603212

  5. Antimicrobial and antistaphylococcal biofilm activity from the sea urchin Paracentrotus lividus

    Schillaci, D.; Arizza, V.; Parrinello, N.;

    2010-01-01

    Aims: Staphylococcal biofilm-associated infections are resistant to conventional antibiotics. Consequently, new agents are needed to treat them. With this aim, we focused on the effector cells (coelomocytes) of the sea urchin Paracentrotus lividus immune system. Methods and Results: We tested the...

  6. Detection of DNA damage in mussels and sea urchins exposed to crude oil using comet assay

    The single-cell microgel electrophoresis assay or the comet assay was used to evaluate DNA damage of dispersed crude oil on sea urchins (Strongylocentrotus droebachiensis) and mussels (Mytilus edulis L.). Sea urchins were exposed to 0.06 and 0.25 mg/L dispersed crude oil in a continuous flow system, while the mussels were exposed to 0.015, 0.06 and 0.25 mg/L dispersed crude oil. Sea urchin coelomocytes and mussel haemocytes were sampled after 4 and 5 weeks exposure, respectively. In the sea urchin coelomocytes, there was a significant concentration-related increase in the percentage of DNA in comet tail. In mussel haemocytes, there was a significantly higher percentage of DNA in comet tail for all treatments compared to the control. The responses were concentration-related up to 0.06 mg/L oil. The two highest exposure concentrations of mussels were not significantly different from each other. These results indicate that the comet assay can be used for biomonitoring of DNA damage in marine invertebrates following oil contamination. (author)

  7. Identification and developmental expression of the ets gene family in the sea urchin (Strongylocentrotus purpuratus).

    Rizzo, Francesca; Fernandez-Serra, Montserrat; Squarzoni, Paola; Archimandritis, Aristea; Arnone, Maria I

    2006-12-01

    A systematic search in the available scaffolds of the Strongylocentrotus purpuratus genome has revealed that this sea urchin has 11 members of the ets gene family. A phylogenetic analysis of these genes showed that almost all vertebrate ets subfamilies, with the exception of one, so far found only in mammals, are each represented by one orthologous sea urchin gene. The temporal and spatial expression of the identified ETS factors was also analyzed during embryogenesis. Five ets genes (Sp-Ets1/2, Sp-Tel, Sp-Pea, Sp-Ets4, Sp-Erf) are also maternally expressed. Three genes (Sp-Elk, Sp-Elf, Sp-Erf) are ubiquitously expressed during embryogenesis, while two others (Sp-Gabp, Sp-Pu.1) are not transcribed until late larval stages. Remarkably, five of the nine sea urchin ets genes expressed during embryogenesis are exclusively (Sp-Ets1/2, Sp-Erg, Sp-Ese) or additionally (Sp-Tel, Sp-Pea) expressed in mesenchyme cells and/or their progenitors. Functional analysis of Sp-Ets1/2 has previously demonstrated an essential role of this gene in the specification of the skeletogenic mesenchyme lineage. The dynamic, and in some cases overlapping and/or unique, developmental expression pattern of the latter five genes suggests a complex, non-redundant function for ETS factors in sea urchin mesenchyme formation and differentiation. PMID:16997294

  8. Determinants of Paracentrotus lividus sea urchin recruitment under oligotrophic conditions: Implications for conservation management.

    Oliva, Silvia; Farina, Simone; Pinna, Stefania; Guala, Ivan; Agnetta, Davide; Ariotti, Pierre Antoine; Mura, Francesco; Ceccherelli, Giulia

    2016-06-01

    Sea urchins may deeply shape the structure of macrophyte-dominated communities and require the implementation of sustainable management strategies. In the Mediterranean, the identification of the major recruitment determinants of the keystone sea urchin species Paracentrotus lividus is required, so that source areas of the populations can be identified and exploitation or programmed harvesting can be spatially managed. In this study a collection of eight possible determinants, these encompassing both the biotic (larvae, adult sea urchins, fish, encrusting coralline algae, habitat type and spatial arrangement of habitats) and abiotic (substrate complexity and nutritional status) realms was considered at different spatial scales (site, area, transect and quadrat). Data from a survey including sites subject to different levels of human influence (i.e. from urbanized to protected areas), but all corresponding to an oligotrophic and low-populated region were fitted by means of a generalized linear mixed model. Despite the extensive sampling effort of benthic quadrats, an overall paucity of recruits was found, recruits being aggregated in a very small number of quadrats and in few areas. The analysis of data detected substrate complexity, and adult sea urchin and predatory fish abundances as the momentous determinants of Paracentrotus lividus recruitment. Possible mechanisms of influence are discussed beyond the implications of conservation management. PMID:27043483

  9. Sulphation as a metabolic pathway for oestradiol in the sea urchin Strongylocentrotus franciscanus

    Creange, John E.; Szego, Clara M.

    1967-01-01

    1. Aerobic incubation of [14C]oestradiol, in the presence of surviving gut tissue of the sea urchin Strongylocentrotus franciscanus, or a soluble enzyme system prepared therefrom, resulted in rapid formation of a water-soluble metabolite, identified as oestradiol 3-sulphate. 2. No evidence was obtained for the formation of other metabolic derivatives by the urchin-gut enzymes, or for the presence of the sulphating capacity in any other tissues of the organism under the conditions used. 3. The data are consistent with the possibility that oestradiol, previously detected in the gonads, is synthesized therein and excreted in a conjugated, highly water-soluble form via the gut. PMID:16742507

  10. Advances in the cryopreservation of sea-urchin embryos: Potential application in marine water quality assessment.

    Bellas, Juan; Paredes, Estefanía

    2011-06-01

    Among the most widely used biological techniques in marine pollution assessment, the sea-urchin embryo-larval bioassay is in an advanced developmental stage. Cryopreservation might help to overcome the problem of the spawning seasonality and therefore strengthen the use of those embryo-larval bioassays. This work investigates different factors influencing cryopreservation of sea-urchin embryos, including the cooling rates and holding temperatures, the seeding, or the impact of plunging into liquid nitrogen. The blastula stage yielded better results than the fertilised egg, and the most effective cryoprotectants combination was dimethyl sulfoxide 1.5M plus trehalose 0.04M. The optimised protocol developed begins with an initial hold at 4°C for 2min, followed by cooling at -1°Cmin(-1) to -12°C. At this point a seeding step was incorporated with a 2min hold, followed by a second cooling at -1°Cmin(-1) to -80°C. After a final hold of 2min the cryovials are transferred into liquid nitrogen for storage. Although the cryopreservation processes might cause a delay in the development of sea-urchin embryos, high larval growth (71-98% of controls) was obtained when cryopreserved blastulae were further incubated for 72-96h in artificial seawater. We conclude that embryo-larval bioassays with cryopreserved sea-urchin blastulae are suitable for use in marine pollution monitoring programs and may be considered as an acceptable solution to the reproductive seasonality of sea-urchin species. PMID:21338597

  11. Sea urchin coelomocytes are resistant to a variety of DNA damaging agents

    Increasing anthropogenic activities are creating environmental pressures that threaten marine ecosystems. Effective environmental health assessment requires the development of rapid, sensitive, and cost-effective tools to predict negative impacts at the individual and ecosystem levels. To this end, a number of biological assays using a variety of cells and organisms measuring different end points have been developed for biomonitoring programs. The sea urchin fertilization/development test has been useful for evaluating environmental toxicology and it has been proposed that sea urchin coelomocytes represent a novel cellular biosensor of environmental stress. In this study we investigated the sensitivity of coelomocytes from the sea urchin Lytechinus variegatus to a variety of DNA-damaging agents including ultraviolet (UV) radiation, hydrogen peroxide (H2O2), methylmethane sulfonate (MMS) and benzo[a]pyrene (BaP). LD50 values determined for coelomocytes after 24 h of exposure to these DNA damaging agents indicated a high level of resistance to all treatments. Significant increases in the formation of apurinic/apyrimidinic (AP or abasic) sites in DNA were only detected using high doses of H2O2, MMS and UV radiation. Comparison of sea urchin coelomocytes with hemocytes from the gastropod mollusk Aplysia dactylomela and the decapod crustacean Panulirus argus indicated that sensitivity to different DNA damaging agents varies between species. The high level of resistance to genotoxic agents suggests that DNA damage may not be an informative end point for environmental health assessment using sea urchin coelomocytes however, natural resistance to DNA damaging agents may have implications for the occurrence of neoplastic disease in these animals.

  12. Sea urchin coelomocytes are resistant to a variety of DNA damaging agents

    Loram, Jeannette; Raudonis, Renee; Chapman, Jecar; Lortie, Mae [Bermuda Institute of Ocean Sciences, St. George' s, Bermuda, GE 01 (Bermuda); Bodnar, Andrea, E-mail: andrea.bodnar@bios.edu [Bermuda Institute of Ocean Sciences, St. George' s, Bermuda, GE 01 (Bermuda)

    2012-11-15

    Increasing anthropogenic activities are creating environmental pressures that threaten marine ecosystems. Effective environmental health assessment requires the development of rapid, sensitive, and cost-effective tools to predict negative impacts at the individual and ecosystem levels. To this end, a number of biological assays using a variety of cells and organisms measuring different end points have been developed for biomonitoring programs. The sea urchin fertilization/development test has been useful for evaluating environmental toxicology and it has been proposed that sea urchin coelomocytes represent a novel cellular biosensor of environmental stress. In this study we investigated the sensitivity of coelomocytes from the sea urchin Lytechinus variegatus to a variety of DNA-damaging agents including ultraviolet (UV) radiation, hydrogen peroxide (H{sub 2}O{sub 2}), methylmethane sulfonate (MMS) and benzo[a]pyrene (BaP). LD{sub 50} values determined for coelomocytes after 24 h of exposure to these DNA damaging agents indicated a high level of resistance to all treatments. Significant increases in the formation of apurinic/apyrimidinic (AP or abasic) sites in DNA were only detected using high doses of H{sub 2}O{sub 2}, MMS and UV radiation. Comparison of sea urchin coelomocytes with hemocytes from the gastropod mollusk Aplysia dactylomela and the decapod crustacean Panulirus argus indicated that sensitivity to different DNA damaging agents varies between species. The high level of resistance to genotoxic agents suggests that DNA damage may not be an informative end point for environmental health assessment using sea urchin coelomocytes however, natural resistance to DNA damaging agents may have implications for the occurrence of neoplastic disease in these animals.

  13. Genome editing in sea urchin embryos by using a CRISPR/Cas9 system.

    Lin, Che-Yi; Su, Yi-Hsien

    2016-01-15

    Sea urchin embryos are a useful model system for investigating early developmental processes and the underlying gene regulatory networks. Most functional studies using sea urchin embryos rely on antisense morpholino oligonucleotides to knockdown gene functions. However, major concerns related to this technique include off-target effects, variations in morpholino efficiency, and potential morpholino toxicity; furthermore, such problems are difficult to discern. Recent advances in genome editing technologies have introduced the prospect of not only generating sequence-specific knockouts, but also providing genome-engineering applications. Two genome editing tools, zinc-finger nuclease (ZFN) and transcription activator-like effector nucleases (TALENs), have been utilized in sea urchin embryos, but the resulting efficiencies are far from satisfactory. The CRISPR (clustered regularly interspaced short palindromic repeat)-Cas9 (CRISPR-associated nuclease 9) system serves as an easy and efficient method with which to edit the genomes of several established and emerging model organisms in the field of developmental biology. Here, we apply the CRISPR/Cas9 system to the sea urchin embryo. We designed six guide RNAs (gRNAs) against the well-studied nodal gene and discovered that five of the gRNAs induced the expected phenotype in 60-80% of the injected embryos. In addition, we developed a simple method for isolating genomic DNA from individual embryos, enabling phenotype to be precisely linked to genotype, and revealed that the mutation rates were 67-100% among the sequenced clones. Of the two potential off-target sites we examined, no off-target effects were observed. The detailed procedures described herein promise to accelerate the usage of CRISPR/Cas9 system for genome editing in sea urchin embryos. PMID:26632489

  14. Effects of five southern California macroalgal diets on consumption, growth, and gonad weight, in the purple sea urchin Strongylocentrotus purpuratus

    Matthew C. Foster

    2015-01-01

    Full Text Available Consumer growth and reproductive capacity are direct functions of diet. Strongylocentrotid sea urchins, the dominant herbivores in California kelp forests, strongly prefer giant kelp (Macrocystis pyrifera, but are highly catholic in their ability to consume other species. The biomass of Macrocystis fluctuates greatly in space and time, and the extent to which urchins can use alternate species of algae or a mixed diet of multiple algal species to maintain fitness when giant kelp is unavailable is unknown. We experimentally examined the effects of single and mixed species diets on consumption, growth and gonad weight in the purple sea urchin Strongylocentrotus purpuratus. Urchins were fed single species diets consisting of one of four common species of macroalgae (the kelps Macrocystis pyrifera and Pterygophora californica, and the red algae Chondracanthus corymbiferus and Rhodymenia californica (hereafter referred to by genus or a mixed diet containing all four species ad libitum over a 13-week period in a controlled laboratory setting. Urchins fed Chondracanthus, Macrocystis and a mixed diet showed the highest growth (in terms of test diameter, wet weight and jaw length and gonad weight, while urchins fed Pterygophora and Rhodymenia showed the lowest. Urchins consumed their preferred food, Macrocystis, at the highest rate when offered a mixture, but consumed Chondracanthus or Macrocystis at similar rates when the two algae were offered alone. The differences in urchin feeding behavior and growth observed between these diet types suggest the relative availability of the algae tested here could affect urchin populations and their interactions with the algal assemblage. The fact that the performance of urchins fed Chondracanthus was similar or higher than those fed the preferred Macrocystis suggests that the availability of the former could could sustain growth and reproduction of purple sea urchins during times of low Macrocystis abundance as is

  15. Effects of produced water on gametogenesis and gamete performance in the purple sea urchin (Stronglyocentrotus purpuratus)

    The author examined the effects of a chronic exposure to produced water (an oil production effluent) discharge on the gametogenesis and gamete performance of the purple sea urchin (Strongylocentrotus purpuratus) using an in situ caging experiment. Adult purple urchins were kept in benthic cages arrayed down-field from a discharging diffuser at 13 sites with distances ranging from 5m to 1,000m. Cage exposures were maintained in the field for eight weeks and each cage held 25 urchins. Gametogenesis was examined for each sex by comparing a size-independent measure of gonad mass as determined by analysis of covariance. The author found that there was a significant negative relationship between gonad mass and cage distance for both sexes, indicating that urchins living closer to the outfall produced significantly larger gonads. Gamete performance was measured through a fertilization kinetic bioassay that holds the concentration of eggs constant and varies the amount of sperm added. The proportion of eggs fertilized under each sperm concentration was determined and the response fit to a kinetics model. Significant differences were found in the fertilizability of eggs between cages. This showed a positive relationship with distance away from the outfall. The findings indicate that while adult urchins exposed to a produced water outfall produced larger gonads, they suffered a marked decreases in gamete performance

  16. Physiological compensation for environmental acidification is limited in the deep-sea urchin Strongylocentrotus fragilis

    Taylor, J. R.; Lovera, C.; Whaling, P. J.; Buck, K. R.; Pane, E. F.; Barry, J. P.

    2013-05-01

    Anthropogenic CO2 is now reaching depths over 1000 m in the Eastern Pacific, overlapping the Oxygen Minimum Zone (OMZ). Deep-sea animals - particularly, calcifiers - are suspected to be especially sensitive to environmental acidification associated with global climate change. We have investigated the effects of hypercapnia and hypoxia on the deep-sea urchin Strongylocentrotus fragilis, during two long-term exposure experiments (1 month and 4 month) at three levels of reduced pH at in situ O2 levels of approx. 10% saturation, and also to control pH at 100% O2 saturation. During the first experiment, internal acid-base balance was investigated during a one-month exposure; results show S. fragilis has limited ability to compensate for the respiratory acidosis brought on by reduced pH, due in part to low non-bicarbonate extracellular fluid buffering capacity. During the second experiment, longer-term effects of hypercapnia and variable O2 on locomotion, feeding, growth, and gonadosomatic index (GSI) were investigated; results show significant mortality and correlation of all measured parameters with environmental acidification at pH 6.6. Transient adverse effects on locomotion and feeding were seen at pH 7.2, without compromise of growth or GSI. Based on the expected changes in ocean pH and oxygen, results suggest extinction of S. fragilis in the eastern North Pacific is unlikely. Rather, we expect a shoaling and contraction of its bathymetric range.

  17. Physiological compensation for environmental acidification is limited in the deep-sea urchin Strongylocentrotus fragilis

    J. R. Taylor

    2013-05-01

    Full Text Available Anthropogenic CO2 is now reaching depths over 1000 m in the Eastern Pacific, overlapping the Oxygen Minimum Zone (OMZ. Deep-sea animals – particularly, calcifiers – are suspected to be especially sensitive to environmental acidification associated with global climate change. We have investigated the effects of hypercapnia and hypoxia on the deep-sea urchin Strongylocentrotus fragilis, during two long-term exposure experiments (1 month and 4 month at three levels of reduced pH at in situ O2 levels of approx. 10% saturation, and also to control pH at 100% O2 saturation. During the first experiment, internal acid-base balance was investigated during a one-month exposure; results show S. fragilis has limited ability to compensate for the respiratory acidosis brought on by reduced pH, due in part to low non-bicarbonate extracellular fluid buffering capacity. During the second experiment, longer-term effects of hypercapnia and variable O2 on locomotion, feeding, growth, and gonadosomatic index (GSI were investigated; results show significant mortality and correlation of all measured parameters with environmental acidification at pH 6.6. Transient adverse effects on locomotion and feeding were seen at pH 7.2, without compromise of growth or GSI. Based on the expected changes in ocean pH and oxygen, results suggest extinction of S. fragilis in the eastern North Pacific is unlikely. Rather, we expect a shoaling and contraction of its bathymetric range.

  18. Cathepsin B/X is secreted by Echinometra lucunter sea urchin spines, a structure rich in granular cells and toxins

    Sciani, Juliana Mozer; Antoniazzi, Marta Maria; Neves, Adriana da Costa; Pimenta, Daniel Carvalho

    2013-01-01

    Background Echinometra lucunter is a common American sea urchin responsible for the majority of the marine accidents in Brazil. Although not lethal, these accidents are reported to be extremely painful. Recently, our group described the presence of toxins in its spines that contribute to the pathological reactions. Additionally, we have observed that the E. lucunter spines can regenerate when broken. In the present work we evaluated the enzymatic activities of sea urchin spine extracts in ord...

  19. Sperm velocity and longevity trade off each other and influence fertilization in the sea urchin Lytechinus variegatus.

    Levitan, D R

    2000-01-01

    The theoretical prediction that fast sperm should be more effective at fertilizing eggs has never been documented empirically. Interspecific comparisons suggest an inverse relationship between sperm velocity and sperm longevity but this trade-off has never been demonstrated within a species. Here I investigate how sperm velocity and sperm longevity influence the patterns of fertilization in the sea urchin Lytechinus variegatus. In the laboratory I examined 11 male female pairs of sea urchins ...

  20. RNA Deep Sequencing Reveals Differential MicroRNA Expression during Development of Sea Urchin and Sea Star

    Kadri, Sabah; Hinman, Veronica F.; Benos, Panayiotis V.

    2011-01-01

    microRNAs (miRNAs) are small (20–23 nt), non-coding single stranded RNA molecules that act as post-transcriptional regulators of mRNA gene expression. They have been implicated in regulation of developmental processes in diverse organisms. The echinoderms, Strongylocentrotus purpuratus (sea urchin) and Patiria miniata (sea star) are excellent model organisms for studying development with well-characterized transcriptional networks. However, to date, nothing is known about the role of miRNAs d...

  1. The sea urchin, a versatile model for eco-toxicity studies and ecological experimental research

    D. Privitera

    2011-01-01

    Full Text Available Echinoderm early developmental stages represent a good tool for toxicity testing in different fields, ranging from environment to food contamination, and in full respect of the 3Rs objectives (Reduction, Refinement, Replacement of animal experiments, that will lead to the reduction of vertebrate use for toxicity testing. Further, sea urchins are key species in a wide range of marine habitats, as they are able to structure algal community. Experiments and observations aiming at the  characterization of anthropogenic or climate changes effects on their settlement, population structure, feeding behaviour and reproductive condition, may be useful to describe future scenarios regarding the whole marine community. The present paper represents a short review of the possible applications of eco-toxicity bioassays using Paracentrotus lividus gametes and embryos. Further, examples of ecological researches, involving sea urchins, aiming at the definition of future scenarios will be preserved.

  2. Reduced O2 and elevated ROS in sea urchin embryos leads to defects in ectoderm differentiation.

    Agca, Cavit; Klein, William H; Venuti, Judith M

    2009-07-01

    The sea urchin oral-aboral (OA) axis is established in part by Nodal signaling. The OA axis is also influenced by treatments affecting respiration and Nodal transcription is influenced by redox-dependent transcription factors. This suggests that intracellular redox state plays a role in OA axis specification. Since cellular redox state can be altered by the formation of excess reactive oxygen species (ROS), and hypoxia and paraquat generate ROS in cells, we asked whether these treatments affected specification of the OA axis and Nodal expression. Embryos cultured under conditions that elevate ROS, demonstrate perturbed ectoderm specification, but other territories are not affected. Immunohistochemical and Q-RT-PCR analyses revealed that both oral and aboral ectoderm genes are downregulated. Our results argue that elevating ROS in sea urchin embryos by these treatments blocks early steps in ectoderm differentiation preceding the polarization of the ectoderm into oral and aboral territories. PMID:19517573

  3. Characteristics of palindromic sequences in DNA of the sea urchin Stronglyocentrotus intermedius

    The fraction of palindromic sequences in the nuclear DNA of the sea urchin S. intermedius was characterized. Using chromatography on hydroxyapatite and treatment with S1 nuclease, it was shown that the fraction of palindromic sequences more than doubles when the sodium concentration in solution is increased or the temperature of reassociation is lowered. The increase is due to the involvement of inverted repeats in reassociation, which are characterized by a substantial nonhomologous character and/or the presence of an extended intervening DNA sequence. It was found by the method of reassociation of a nicked palindrome fraction with an excess of total homologous DNA that most of the inverted repeats in the sea urchin genome are unique sequences. The complexity of the palindrome fraction was estimated at 8.2 x 107 nucleotide pairs, and the number of palindromes per haploid genome ∼ 500,000

  4. High ordered biomineralization induced by carbon nanoparticles in the sea urchin Paracentrotus lividus

    A surprising and unexpected biomineralization process was observed during toxicological assessment of carbon nanoparticles on Paracentrotus lividus (sea urchin) pluteus larvae. The larvae activate a process of defense against external material, by incorporating the nanoparticles into microstructures of aragonite similarly to pearl oysters. Aiming at a better understanding of this phenomenon, the larvae were exposed to increasing concentrations of carbon nanoparticles and the biomineralization products were analyzed by electron microscopy, x-ray diffraction and Raman spectroscopy. In order to evaluate the possible influence of Sp-CyP-1 expression on this biomineralization process by larvae, analyses of gene expression (Sp-CyP-1) and calcein labeling were performed. Overall, we report experimental evidence about the capability of carbon nanoparticles to induce an increment of Sp-CyP-1 expression with the consequent activation of a biomineralization process leading to the production of a new pearl-like biomaterial never previously observed in sea urchins. (paper)

  5. The sea urchin, a versatile model for eco-toxicity studies and ecological experimental research

    Privitera, D; M.G. Aluigi; C Falugi; Chiantore, M.

    2011-01-01

    Echinoderm early developmental stages represent a good tool for toxicity testing in different fields, ranging from environment to food contamination, and in full respect of the 3Rs objectives (Reduction, Refinement, Replacement of animal experiments), that will lead to the reduction of vertebrate use for toxicity testing. Further, sea urchins are key species in a wide range of marine habitats, as they are able to structure algal community. Experiments and observations aiming at the  character...

  6. Effects of oscillatory flow on fertilization in the green sea urchin Strongylocentrotus droebachiensis

    Kregting, Louise T.; Bass, Anna L.; Guadayol, Òscar; Yund, Philip O.; Thomas, Florence I. M.

    2013-01-01

    Broadcast spawning invertebrates that live in shallow, high-energy coastal habitats are subjected to oscillatory water motion that creates unsteady flow fields above the surface of animals. The frequency of the oscillatory fluctuations is driven by the wave period, which will influence the stability of local flow structures and may affect fertilization processes. Using an oscillatory water tunnel, we quantified the percentage of eggs fertilized on or near spawning green sea urchins, Strongylo...

  7. The immune gene repertoire encoded in the purple sea urchin genome.

    Hibino, Taku; Loza-Coll, Mariano; Messier, Cynthia; Majeske, Audrey J; Cohen, Avis H; Terwilliger, David P; Buckley, Katherine M; Brockton, Virginia; Nair, Sham V; Berney, Kevin; Fugmann, Sebastian D; Anderson, Michele K; Pancer, Zeev; Cameron, R Andrew; Smith, L Courtney; Rast, Jonathan P

    2006-12-01

    Echinoderms occupy a critical and largely unexplored phylogenetic vantage point from which to infer both the early evolution of bilaterian immunity and the underpinnings of the vertebrate adaptive immune system. Here we present an initial survey of the purple sea urchin genome for genes associated with immunity. An elaborate repertoire of potential immune receptors, regulators and effectors is present, including unprecedented expansions of innate pathogen recognition genes. These include a diverse array of 222 Toll-like receptor (TLR) genes and a coordinate expansion of directly associated signaling adaptors. Notably, a subset of sea urchin TLR genes encodes receptors with structural characteristics previously identified only in protostomes. A similarly expanded set of 203 NOD/NALP-like cytoplasmic recognition proteins is present. These genes have previously been identified only in vertebrates where they are represented in much lower numbers. Genes that mediate the alternative and lectin complement pathways are described, while gene homologues of the terminal pathway are not present. We have also identified several homologues of genes that function in jawed vertebrate adaptive immunity. The most striking of these is a gene cluster with similarity to the jawed vertebrate Recombination Activating Genes 1 and 2 (RAG1/2). Sea urchins are long-lived, complex organisms and these findings reveal an innate immune system of unprecedented complexity. Whether the presumably intense selective processes that molded these gene families also gave rise to novel immune mechanisms akin to adaptive systems remains to be seen. The genome sequence provides immediate opportunities to apply the advantages of the sea urchin model toward problems in developmental and evolutionary immunobiology. PMID:17027739

  8. The immune gene repertoire encoded in the purple sea urchin genome

    Hibino, Taku; Loza-Coll, Mariano; Messier, Cynthia; Majeske, Audrey J.; Cohen, Avis H.; Terwilliger, David P.; Buckley, Katherine M.; Brockton, Virginia; Nair, Sham V.; Berney, Kevin; Fugmann, Sebastian D.; Anderson, Michele K.; Pancer, Zeev; Cameron, R. Andrew; Smith, L Courtney

    2006-01-01

    Echinoderms occupy a critical and largely unexplored phylogenetic vantage point from which to infer both the early evolution of bilaterian immunity and the underpinnings of the vertebrate adaptive immune system. Here we present an initial survey of the purple sea urchin genome for genes associated with immunity. An elaborate repertoire of potential immune receptors, regulators and effectors is present, including unprecedented expansions of innate pathogen recognition genes. These include a di...

  9. Inhibition of glycoprotein processing blocks assembly of spicules during development of the sea urchin embryo

    1990-01-01

    Previous studies have implicated an 130-kD glycoprotein containing complex, N-linked oligosaccharide chain(s) in the process of spicule formation in sea urchin embryos. To ascertain whether the processing of high mannose oligosaccharides to complex oligosaccharides is necessary for spiculogenesis, intact embryos and cultures of spicule-forming primary mesenchyme cells were treated with glycoprotein processing inhibitors. In both the embryonic and cell culture systems 1- deoxymannojirimycin (1...

  10. Aggregation of sea urchin phagocytes is augmented in vitro by lipopolysaccharide.

    Majeske, Audrey J; Bayne, Christopher J; Smith, L Courtney

    2013-01-01

    Development of protocols and media for culturing immune cells from marine invertebrates has not kept pace with advancements in mammalian immune cell culture, the latter having been driven by the need to understand the causes of and develop therapies for human and animal diseases. However, expansion of the aquaculture industry and the diseases that threaten these systems creates the need to develop cell and tissue culture methods for marine invertebrates. Such methods will enable us to better understand the causes of disease outbreaks and to develop means to avoid and remedy epidemics. We report a method for the short-term culture of phagocytes from the purple sea urchin, Strongylocentrotus purpuratus, by modifying an approach previously used to culture cells from another sea urchin species. The viability of cultured phagocytes from the purple sea urchin decreases from 91.6% to 57% over six days and phagocyte morphology changes from single cells to aggregates leading to the formation of syncytia-like structures. This process is accelerated in the presence of lipopolysaccharide suggesting that phagocytes are capable of detecting this molecular pattern in culture conditions. Sea urchin immune response proteins, called Sp185/333, are expressed on the surface of a subset of phagocytes and have been associated with syncytia-like structures. We evaluated their expression in cultured phagocytes to determine their possible role in cell aggregation and in the formation of syncytia-like structures. Between 0 and 3 hr, syncytia-like structures were observed in cultures when only ~10% of the cells were positive for Sp185/333 proteins. At 24 hr, ~90% of the nuclei were Sp185/333-positive when all of the phagocytes had aggregated into syncytia-like structures. Consequently, we conclude that the Sp185/333 proteins do not have a major role in initiating the aggregation of cultured phagocytes, however the Sp185/333 proteins are associated with the clustered nuclei within the

  11. Autonomy in specification of primordial germ cells and their passive translocation in the sea urchin

    Yajima, Mamiko; Wessel, Gary M.

    2012-01-01

    The process of germ line determination involves many conserved genes, yet is highly variable. Echinoderms are positioned at the base of Deuterostomia and are crucial to understanding these evolutionary transitions, yet the mechanism of germ line specification is not known in any member of the phyla. Here we demonstrate that small micromeres (SMics), which are formed at the fifth cell division of the sea urchin embryo, illustrate many typical features of primordial germ cell (PGC) specificatio...

  12. Ovothiol Isolated from Sea Urchin Oocytes Induces Autophagy in the Hep-G2 Cell Line

    Gian Luigi Russo; Maria Russo; Immacolata Castellano; Alessandra Napolitano; Anna Palumbo

    2014-01-01

    Ovothiols are histidine-derived thiols isolated from sea urchin eggs, where they play a key role in the protection of cells toward the oxidative burst associated with fertilization by controlling the cellular redox balance and recycling oxidized glutathione. In this study, we show that treatment of a human liver carcinoma cell line, Hep-G2, with ovothiol A, isolated from Paracentrotus lividus oocytes, results in a decrease of cell proliferation in a dose-dependent manner. The activation of a...

  13. Muscles advance the teeth in sand dollars and other sea urchins

    Ellers, O.; Telford, M.

    1997-01-01

    We demonstrate the action of the dental promoter muscles in advancing the continuously growing teeth of sand dollars and sea urchins. Teeth wear at the occlusal end, while new calcite is added to the opposite end. Dental ligaments rigidly hold teeth during chewing, but soften and reform during advancement. The source of forces that advance the teeth was unknown until our discovery of the dental promoter muscles. The muscles, which underly the tooth, attach centrally to the stereom of the pyra...

  14. Draft Genome Sequence of Altererythrobacter troitsensis JCM 17037, Isolated from the Sea Urchin Strongylocentrotus intermedius.

    Zhou, Peng; Wu, Yue-Hong; Cheng, Hong; Wang, Chun-Sheng; Xu, Xue-Wei

    2016-01-01

    The habitats of the genus Altererythrobacter are various, including marine sediment, seawater, rhizosphere of wild rice, desert sand, etc. The genome of the type strain of Altererythrobacter troitsensis JCM 17037, isolated from sea urchin, was sequenced. This study would not only facilitate the understanding of the physiology, adaptation, and evolution of the Altererythrobacter species, but also provide a good resource for the study of synthesis of astaxanthin, since several enzymes involved in the production of astaxanthin were predicted. PMID:26769941

  15. Absence of postzygotic isolating mechanisms: evidence from experimental hybridization between two species of tropical sea urchins*

    Rahman, M. Aminur; Uehara, Tsuyoshi; Arshad, Aziz; Yusoff, Fatimah Md; Shamsudin, Mariana Nor

    2012-01-01

    Two reef margin species of tropical sea urchins, Echinometra sp. C (Ec) and Echinometra oblonga (Eo), occur sympatrically on Okinawa intertidal reefs in southern Japan. Hybridization between these species was examined through a series of cross-fertilization experiments. At limited sperm concentrations, where conspecific crosses reached near 100% fertilization, both heterospecific crosses showed high fertilization rates (81%–85%). The compatibility of the gametes demonstrated that if gamete re...

  16. Didymium-like myxogastrids (class Mycetozoa) as endocommensals of sea urchins (Sphaerechinus granularis)

    Dyková, Iva; Lom, Jiří; Dvořáková, Helena; Pecková, Hana; Fiala, Ivan

    2007-01-01

    Roč. 54, č. 1 (2007), s. 1-12. ISSN 0015-5683 R&D Projects: GA ČR GA206/05/2384; GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : Didymium-like myxogastrids * Myxogastrea * sea-urchin amoeba strains * SSU rDNA * flagellar apparatus * phylogeny Subject RIV: EA - Cell Biology Impact factor: 1.000, year: 2007

  17. Cloning of the sea urchin mitochondrial RNA polymerase and reconstitution of the transcription termination system

    Polosa, Paola Loguercio; Deceglie, Stefania; Falkenberg, Maria; Roberti, Marina; Di Ponzio, Barbara; Gadaleta, Maria Nicola; Cantatore, Palmiro

    2007-01-01

    Termination of transcription is a key process in the regulation of mitochondrial gene expression in animal cells. To investigate transcription termination in sea urchin mitochondria, we cloned the mitochondrial RNA polymerase (mtRNAP) of Paracentrotus lividus and used a recombinant form of the enzyme in a reconstituted transcription system, in the presence of the DNA-binding protein mtDBP. Cloning of mtRNAP was performed by a combination of PCR with degenerate primers and library screening. T...

  18. Developing the technology of mayonnaise sauce with sea urchin caviar, laminaria and nettle

    Grokhovsky V. A.

    2015-12-01

    Full Text Available Some aspects of consumer demand on mayonnaise production have been found due to marketing researches. The technology of mayonnaise sauce using such valuable ingredients as sea urchin caviar, laminaria and nettle has been scientifically proved and produced. The formula of the new product composition has been developed; the specimens of such mayonnaise sauce have been made; they have been explored during their storage

  19. Innate immune complexity in the purple sea urchin: diversity of the Sp185/333 system

    L Courtney Smith

    2012-01-01

    The California purple sea urchin, Strongylocentrotus purpuratus, is a long-lived echinoderm with a complex and sophisticated innate immune system. Several large gene families that function in immunity in this species includes the Sp185/333 gene family with ~50 (±10) members. The family shows intriguing sequence diversity and encodes a broad array of diverse yet similar proteins. The genes have two exons of which the second encodes the mature protein and has repeats and blocks of sequence...

  20. Primary cell cultures from sea urchin ovaries: a new experimental tool.

    Mercurio, Silvia; Di Benedetto, Cristiano; Sugni, Michela; Candia Carnevali, M Daniela

    2014-02-01

    In the present work, primary cell cultures from ovaries of the edible sea urchin Paracentrotus lividus were developed in order to provide a simple and versatile experimental tool for researches in echinoderm reproductive biology. Ovary cell phenotypes were identified and characterized by different microscopic techniques. Although cell cultures could be produced from ovaries at all stages of maturation, the cells appeared healthier and viable, displaying a higher survival rate, when ovaries at early stages of gametogenesis were used. In terms of culture medium, ovarian cells were successfully cultured in modified Leibovitz-15 medium, whereas poor results were obtained in minimum essential medium Eagle and medium 199. Different substrates were tested, but ovarian cells completely adhered only on poly-L-lysine. To improve in vitro conditions and stimulate cell proliferation, different serum-supplements were tested. Fetal calf serum and an originally developed pluteus extract were detrimental to cell survival, apparently accelerating processes of cell death. In contrast, cells cultured with sea urchin egg extract appeared larger and healthier, displaying an increased longevity that allowed maintaining them for up to 1 month. Overall, our study provides new experimental bases and procedures for producing successfully long-term primary cell cultures from sea urchin ovaries offering a good potential to study echinoid oogenesis in a controlled system and to investigate different aspects of echinoderm endocrinology and reproductive biology. PMID:24002666

  1. The use of cryopreserved sea urchin embryos (Paracentrotus lividus) in marine quality assessment.

    Paredes, E; Bellas, J

    2015-06-01

    We have established for first time an ecotoxicological bioassay using cryopreserved sea urchin embryos (Paracentotus lividus) and provided a comparison to the already standardized sea urchin embryo-larval bioassay, using selected (organic and inorganic) pollutants and sediment elutriates from 4 different locations from Ria de Vigo harbour (Galicia, NW Iberian Peninsula). A cryopreservation protocol was designed in order to enable the successful cryopreservation and cryobanking of gametes and embryos to be used for marine quality assessment and ensure the accessibility to high quality reproductive material all year round, as an option to conditioning adults for out of season reproduction. The calculated EC50 using the cryopreserved blastula was 53.7 μg L(-1) for copper, 81.0 μg L(-1) for lead, 300.6 μg L(-1) for BP-3 and 300.6 μg L(-1) for 4-MBC. The sensitivity of the classic sea urchin embryo-larval bioassay was compared with the bioassay conducted with cryopreserved blastula. The results showed that the use of cryopreserved blastula bioassay allows detecting lower concentrations of pollutants in comparison with the classic bioassay. PMID:25725396

  2. Cryopreservation of sea urchin embryos (Paracentrotus lividus) applied to marine ecotoxicological studies.

    Paredes, Estefanía; Bellas, Juan

    2009-12-01

    Current strategies for marine pollution monitoring are based on the integration of chemical and biological techniques. The sea urchin embryo-larval bioassays are among the biological methods most widely used worldwide. Cryopreservation of early embryos of sea urchins could provide a useful tool to overcome one of the main limitations of such bioassays, the availability of high quality biological material all year round. The present study aimed to determine the suitability of several permeant (dimethyl sulfoxide, Me(2)SO; propylene glycol, PG; and ethylene glycol, EG) and non-permeant (trehalose, TRE; polyvinylpyrrolidone, PVP) cryoprotectant agents (CPAs) and their combination, for the cryopreservation of eggs and embryos of the sea urchin Paracentrotus lividus. On the basis of the CPAs toxicity, PG and EG, in combination with PVP, seem to be most suitable for the cryopreservation of P. lividus eggs and embryos. Several freezing procedures were also assayed. The most successful freezing regime consisted on cooling from 4 to -12 degrees C at 1 degrees C/min, holding for 2 min for seeding, cooling to -20 degrees C at 0.5 degrees C/min, and then cooling to -35 degrees C at 1 degrees C/min. Maximum normal larvae percentages of 41.5% and 68.5%, and maximum larval growth values of 42.9% and 60.5%, were obtained for frozen fertilized eggs and frozen blastulae, respectively. PMID:19786009

  3. Morphological evolution in sea urchin development: hybrids provide insights into the pace of evolution.

    Byrne, Maria; Voltzow, Janice

    2004-04-01

    Hybridisations between related species with divergent ontogenies can provide insights into the bases for evolutionary change in development. One example of such hybridisations involves sea urchin species that exhibit either standard larval (pluteal) stages or those that develop directly from embryo to adult without an intervening feeding larval stage. In such crosses, pluteal features were found to be restored in fertilisations of the eggs of some direct developing sea urchins (Heliocidaris erythrogramma) with the sperm of closely (Heliocidaris tuberculata) and distantly (Pseudoboletia maculata) related species with feeding larvae. Such results can be argued to support the punctuated equilibrium model-conservation in pluteal regulatory systems and a comparatively rapid switch to direct development in evolution.1,2 Generation of hybrids between distantly related direct developers may, however, indicate evolutionary convergence. The 'rescue' of pluteal features by paternal genomes may require maternal factors from H. erythrogramma because the larva of this species has pluteal features. In contrast, pluteal features were not restored in hybridisations with the eggs of Holopneustes purpurescens, which lacks pluteal features. How much of pluteal development can be lost before it cannot be rescued in such crosses? The answer awaits hybridisations among indirect and direct developing sea urchins differing in developmental phenotype, in parallel with investigations of the genetic programs involved. PMID:15057932

  4. Different migration patterns of sea urchin and mouse sperm revealed by a microfluidic chemotaxis device.

    Haixin Chang

    Full Text Available Chemotaxis refers to a process whereby cells move up or down a chemical gradient. Sperm chemotaxis is known to be a strategy exploited by marine invertebrates such as sea urchins to reach eggs efficiently in moving water. Less is understood about how or whether chemotaxis is used by mammalian sperm to reach eggs, where fertilization takes place within the confinement of a reproductive tract. In this report, we quantitatively assessed sea urchin and mouse sperm chemotaxis using a recently developed microfluidic model and high-speed imaging. Results demonstrated that sea urchin Arbacia punctulata sperm were chemotactic toward the peptide resact with high chemotactic sensitivity, with an average velocity Vx up the chemical gradient as high as 20% of its average speed (238 μm/s, while mouse sperm displayed no statistically significant chemotactic behavior in progesterone gradients, which had been proposed to guide mammalian sperm toward eggs. This work demonstrates the validity of a microfluidic model for quantitative sperm chemotaxis studies, and reveals a biological insight that chemotaxis up a progesterone gradient may not be a universal strategy for mammalian sperm to reach eggs.

  5. Cell mediated immune response of the Mediterranean sea urchin Paracentrotus lividus after PAMPs stimulation.

    Romero, A; Novoa, B; Figueras, A

    2016-09-01

    The Mediterranean sea urchin (Paracentrotus lividus) is of great ecological and economic importance for the European aquaculture. Yet, most of the studies regarding echinoderm's immunological defense mechanisms reported so far have used the sea urchin Strongylocentrotus purpuratus as a model, and information on the immunological defense mechanisms of Paracentrotus lividus and other sea urchins, is scarce. To remedy this gap in information, in this study, flow cytometry was used to evaluate several cellular immune mechanisms, such as phagocytosis, cell cooperation, and ROS production in P. lividus coelomocytes after PAMP stimulation. Two cell populations were described. Of the two, the amoeboid-phagocytes were responsible for the phagocytosis and ROS production. Cooperation between amoeboid-phagocytes and non-adherent cells resulted in an increased phagocytic response. Stimulation with several PAMPs modified the phagocytic activity and the production of ROS. The premise that the coelomocytes were activated by the bacterial components was confirmed by the expression levels of two cell mediated immune genes: LPS-Induced TNF-alpha Factor (LITAF) and macrophage migration inhibitory factor (MIF). These results have helped us understand the cellular immune mechanisms in P. lividus and their modulation after PAMP stimulation. PMID:27113124

  6. Sensitivity to UV radiation in early life stages of the Mediterranean sea urchin Sphaerechinus granularis (Lamarck)

    Nahon, Sarah [UPMC Univ Paris 06, UMR 7621, LOBB, Observatoire Oceanologique, F-66651, Banyuls/mer (France); CNRS, UMR 7621, LOBB, Observatoire Oceanologique, F-66651, Banyuls/mer (France); Castro Porras, Viviana A. [UPMC Univ Paris 06, UMR 7621, LOBB, Observatoire Oceanologique, F-66651, Banyuls/mer (France); Pruski, Audrey M. [UPMC Univ Paris 06, UMR 7621, LOBB, Observatoire Oceanologique, F-66651, Banyuls/mer (France); CNRS, UMR 7621, LOBB, Observatoire Oceanologique, F-66651, Banyuls/mer (France); Charles, Francois [UPMC Univ Paris 06, UMR 7621, LOBB, Observatoire Oceanologique, F-66651, Banyuls/mer (France); CNRS, UMR 7621, LOBB, Observatoire Oceanologique, F-66651, Banyuls/mer (France)], E-mail: charles@obs-banyuls.fr

    2009-03-01

    The sea urchin Sphaerechinus granularis was used to investigate the impact of relevant levels of UV-B radiation on the early life stages of a common Mediterranean free spawning benthic species. Sperm, eggs and embryos were exposed to a range of UV radiation doses. The resulting endpoints were evaluated in terms of fertilisation success, development and survival rates. Above a weighted UV radiation dose of 0.0029 kJ m{sup -2}, fertilisation capability of irradiated sperm decreased rapidly. The exposure of the eggs to 0.0175 kJ m{sup -2} and more led to delayed and inhibited development with ensuing embryonic morphological abnormalities. One-day old larvae remained strongly sensitive to UV radiation as shown by the 50% decrease of the larval survival rate for a dose of 0.025 kJ m{sup -2} UVR. The elevated sensitivity of embryos to experimental UVR went along with a lack of significant amount of sunscreen compounds (e.g., mycosporine-like amino acids) in the eggs. The present results demonstrated that gamete viability and embryonic development may be significantly impaired by solar UV radiation in S. granularis, compromising in this way the reproduction of the species. Unless adaptive behavioural reproductive strategies exist, the influence of ambient UV radiation appears as a selective force for population dynamics of broadcast spawners in the shallow benthic Mediterranean environment.

  7. [Standardization of larval development of the sea urchin, Paracentrotus lividus, as tool for the assessment sea water quality].

    Pétinay, Stéphanie; Chataigner, Claire; Basuyaux, Olivier

    2009-12-01

    All stages of development of the sea urchin are of interest in ecotoxicology; the largest number of prior works concerns studies on gametes. Previous studies indicated that the use of sea urchin larvae was difficult because of the need to obtain the parent generations and good quality gametes. Progress in sea urchin culture has allowed one to standardize the method. The proposed technique is based on an evaluation of the number of non-developing fertilized eggs, on the frequency of malformations, and on the length of the larvae at 96 hours, using parents raised under well-controlled conditions. Temperature (18-22 degrees C), salinity (28-34 ppt) and pH (8-8.4) have been fixed to standardize the proposed biological test. Thirty micrograms per litre of copper reduce significantly the length of the larvae and could be used as a positive control. On the other hand, reconstituted sea water permits an optimal development of the larvae and may be used as negative control. A seasonal follow-up of water quality has been achieved to validate the use of this technique in a surveillance network of water quality. The method may be used whatever the salinity, including fresh and brackish waters. PMID:19931848

  8. Physiological effects of environmental acidification in the deep-sea urchin Strongylocentrotus fragilis

    Taylor, J. R.; Lovera, C.; Whaling, P. J.; Buck, K. R.; Pane, E. F.; Barry, J. P.

    2014-03-01

    Anthropogenic CO2 is now reaching depths over 1000 m in the Eastern Pacific, overlapping the Oxygen Minimum Zone (OMZ). Deep-sea animals are suspected to be especially sensitive to environmental acidification associated with global climate change. We have investigated the effects of elevated pCO2 and variable O2 on the deep-sea urchin Strongylocentrotus fragilis, a species whose range of 200-1200 m depth includes the OMZ and spans a pCO2 range of approx. 600-1200 μatm (approx. pH 7.6 to 7.8). Individuals were evaluated during two exposure experiments (1-month and 4 month) at control and three levels of elevated pCO2 at in situ O2 levels of approx. 10% air saturation. A treatment of control pCO2 at 100% air saturation was also included in experiment two. During the first experiment, perivisceral coelomic fluid (PCF) acid-base balance was investigated during a one-month exposure; results show S. fragilis has limited ability to compensate for the respiratory acidosis brought on by elevated pCO2, due in part to low non-bicarbonate PCF buffering capacity. During the second experiment, individuals were separated into fed and fasted experimental groups, and longer-term effects of elevated pCO2 and variable O2 on righting time, feeding, growth, and gonadosomatic index (GSI) were investigated for both groups. Results suggest that the acidosis found during experiment one does not directly correlate with adverse effects during exposure to realistic future pCO2 levels.

  9. Sea urchin mtDBP is a two-faced transcription termination factor with a biased polarity depending on the RNA polymerase

    Fernandez-Silva, Patricio; Polosa, Paola Loguercio; Roberti, Marina; Di Ponzio, Barbara; Gadaleta, Maria Nicola; Montoya, Julio; Cantatore, Palmiro

    2001-01-01

    The sea urchin mitochondrial displacement (D)-loop binding protein mtDBP has been previously identified and cloned. The polypeptide (348 amino acids) displays a significant homology with the human mitochondrial transcription termination factor mTERF. This similarity, and the observation that the 3′ ends of mitochondrial RNAs coded by opposite strands mapped in correspondence of mtDBP-binding sites, suggested that mtDBP could function as transcription termination factor in sea urchin mitochondria. To investigate such a role we tested the capability of mtDBP bound to its target sequence in the main non-coding region to affect RNA elongation by mitochondrial and bacteriophage T3 and T7 RNA polymerases. We show that mtDBP was able to terminate transcription bidirectionally when initiated by human mitochondrial RNA polymerase but only unidirectionally when initiated by T3 or T7 RNA polymerases. Time-course experiments indicated that mtDBP promotes true transcription termination rather than transcription pausing. These results indicate that mtDBP is able to function as a bipolar transcription termination factor in sea urchin mitochondria. The functional significance of such an activity could be linked to the previously proposed dual role of the protein in modulating mitochondrial DNA transcription and replication. PMID:11713324

  10. Substituting mouse transcription factor Pou4f2 with a sea urchin orthologue restores retinal ganglion cell development

    Mocko-Strand, Julie A.; Wang, Jing; Ullrich-Lüter, Esther; Pan, Ping; Wang, Steven W.; Arnone, Maria Ina; Frishman, Laura J.; Klein, William H.

    2016-01-01

    Pou domain transcription factor Pou4f2 is essential for the development of retinal ganglion cells (RGCs) in the vertebrate retina. A distant orthologue of Pou4f2 exists in the genome of the sea urchin (class Echinoidea) Strongylocentrotus purpuratus (SpPou4f1/2), yet the photosensory structure of sea urchins is strikingly different from that of the mammalian retina. Sea urchins have no obvious eyes, but have photoreceptors clustered around their tube feet disc. The mechanisms that are associated with the development and function of photoreception in sea urchins are largely unexplored. As an initial approach to better understand the sea urchin photosensory structure and relate it to the mammalian retina, we asked whether SpPou4f1/2 could support RGC development in the absence of Pou4f2. To answer this question, we replaced genomic Pou4f2 with an SpPou4f1/2 cDNA. In Pou4f2-null mice, retinas expressing SpPou4f1/2 were outwardly identical to those of wild-type mice. SpPou4f1/2 retinas exhibited dark-adapted electroretinogram scotopic threshold responses, indicating functionally active RGCs. During retinal development, SpPou4f1/2 activated RGC-specific genes and in S. purpuratus, SpPou4f2 was expressed in photoreceptor cells of tube feet in a pattern distinct from Opsin4 and Pax6. Our results suggest that SpPou4f1/2 and Pou4f2 share conserved components of a gene network for photosensory development and they maintain their conserved intrinsic functions despite vast morphological differences in mouse and sea urchin photosensory structures. PMID:26962139

  11. [Juvenile production of the red sea urchin Strongylocentrotus franciscanus (Echinodermata: Echinoidea) in Baja California, Mexico].

    Salas-Garza, A; Carpizo-Ituarte, E; Parés-Sierra, G; Martínez-López, R; Quintana-Rodríguez, R

    2005-12-01

    The red sea urchin Strongylocentrotusfranciscanus (Agassiz 1863) is harvested commercially in Baja California, Mexico, since 1970; however, in the last ten years the capture per unit effort (CPUE) has decreased from 310 kg/fishing unit/day to 120 kg/fishing unit/day. For this reason, actions were taken to develop a culture technology allowing massive production of juveniles for re-stocking natural populations or for growing them commercially. We summarize some of the basic studies and main achievements in this effort. In Baja California, considerably faster larval development (approximately 21 days) has been attained than in the US northwest coast (62 days). Spawning of red sea urchins was routinely induced with KCI while egg fertilization was performed using a 100,000-sperm/ml solution. Six microalgae species were tested and Rhodomonas sp. produced the best larval development. The mean survival rate at the end of the larval period was 25%, but results varied widely with bactch. From the feed ratios tested, best results were obtained using 7000 cel/ml during the first week of larval development, followed by 10,000 cel/ml during the second and 15,000 cel/ml during the third week. KCl proved the most consistent metamorphic inducer, regularly yielding metamorphosis percentages higher than 90%. Metamorphosis was considered complete when the functional jaw that juveniles use for first benthic feeding appeared (as soon as 20 days after induction). With this method several thousands of red sea urchin juveniles were produced. They reached up to 1.5 mm in size during the first 50 days of culture after metamorphosis, showing the great potential for mass production of this species in the laboratory. PMID:17469265

  12. Freezing tolerance of sea urchin embryonic cells: Differentiation commitment and cytoskeletal disturbances in culture.

    Odintsova, Nelly A; Ageenko, Natalya V; Kipryushina, Yulia O; Maiorova, Mariia A; Boroda, Andrey V

    2015-08-01

    This study focuses on the freezing tolerance of sea urchin embryonic cells. To significantly reduce the loss of physiological activity of these cells that occurs after cryopreservation and to study the effects of ultra-low temperatures on sea urchin embryonic cells, we tested the ability of the cells to differentiate into spiculogenic or pigment directions in culture, including an evaluation of the expression of some genes involved in pigment differentiation. A morphological analysis of cytoskeletal disturbances after freezing in a combination of penetrating (dimethyl sulfoxide and ethylene glycol) and non-penetrating (trehalose and polyvinylpyrrolidone) cryoprotectants revealed that the distribution pattern of filamentous actin and tubulin was similar to that in the control cultures. In contrast, very rare spreading cells and a small number of cells with filamentous actin and tubulin were detected after freezing in the presence of only non-penetrating cryoprotectants. The largest number of pigment cells was found in cultures frozen with trehalose or trehalose and dimethyl sulfoxide. The ability to induce the spicule formation was lost in the cells frozen only with non-penetrating cryoprotectants, while it was maximal in cultures frozen in a cryoprotective mixture containing both non-penetrating and penetrating cryoprotectants (particularly, when ethylene glycol was present). Using different markers for cell state assessment, an effective cryopreservation protocol for sea urchin cells was developed: three-step freezing with a low cooling rate (1-2°C/min) and a combination of non-penetrating and penetrating cryoprotectants made it possible to obtain a high level of cell viability (up to 65-80%). PMID:26049089

  13. Characterization of an Alpha Type Carbonic Anhydrase from Paracentrotus lividus Sea Urchin Embryos.

    Karakostis, Konstantinos; Costa, Caterina; Zito, Francesca; Brümmer, Franz; Matranga, Valeria

    2016-06-01

    Carbonic anhydrases (CA) are zinc metalloenzymes that catalyze the reversible hydration of carbon dioxide to bicarbonate. In the sea urchin, CA has a role in the formation of the calcitic skeleton during embryo development. Here, we report a newly identified mRNA sequence from embryos of the sea urchin Paracentrotus lividus, referred to as Pl-can. The complete coding sequence was identified with the aid of both EST databases and experimental procedures. Pl-CAN is a 447 aa-long protein, with an estimated molecular mass of 48.5 kDa and an isoelectric point of 6.83. The in silico study of functional domains showed, in addition to the alpha type CA-specific domain, the presence of an unexpected glycine-rich region at the N-terminal of the molecule. This is not found in any other species described so far, but probably it is restricted to the sea urchins. The phylogenetic analysis indicated that Pl-CAN is evolutionarily closer to human among chordates than to other species. The putative role(s) of the identified domains is discussed. The Pl-can temporal and spatial expression profiles, analyzed throughout embryo development by comparative qPCR and whole-mount in situ hybridization (WMISH), showed that Pl-can mRNA is specifically expressed in the primary mesenchyme cells (PMC) of the embryo and levels increase along with the growth of the embryonic skeleton, reaching a peak at the pluteus stage. A recombinant fusion protein was produced in E. coli and used to raise specific antibodies in mice recognized the endogenous Pl-CAN by Western blot in embryo extracts from gastrula and pluteus. PMID:27230618

  14. Development of scientifically base management towards a sustainable fishery of the common sea urchin, Paracentrotus Lividus, in Sardinia

    Secci, Marco

    2014-01-01

    In recent years sea urchins have become a premium commodity in the world where both males and females of the species are harvested for their gonads, generally referred to as “roe” in the fishery and catering market. Fishing for sea urchins can be a very profitable business during the first 5 to 10 years operations on a new fishing ground. However, after that short period of time, wild populations decline due to the high efficiency and selectivity of the employed fishing techniques. In several...

  15. Role of fibronectin in primary mesenchyme cell migration in the sea urchin

    1985-01-01

    We studied the effect of fibronectin (FN) on the behavior of primary mesenchyme cells isolated from sea urchin mesenchyme blastulae in vitro using a time-lapse technique. The migration of isolated primary mesenchyme cells reconstituted in seawater and horse serum is dependent on the presence or absence of exogenous FN in the culture media. The cells in FN, 4 and 40 micrograms/ml, show a high percentage of migration and migrate long distances, whereas a higher concentration of FN at 400 microg...

  16. Aggregation of sea urchin phagocytes is augmented in vitro by lipopolysaccharide.

    Audrey J Majeske

    Full Text Available Development of protocols and media for culturing immune cells from marine invertebrates has not kept pace with advancements in mammalian immune cell culture, the latter having been driven by the need to understand the causes of and develop therapies for human and animal diseases. However, expansion of the aquaculture industry and the diseases that threaten these systems creates the need to develop cell and tissue culture methods for marine invertebrates. Such methods will enable us to better understand the causes of disease outbreaks and to develop means to avoid and remedy epidemics. We report a method for the short-term culture of phagocytes from the purple sea urchin, Strongylocentrotus purpuratus, by modifying an approach previously used to culture cells from another sea urchin species. The viability of cultured phagocytes from the purple sea urchin decreases from 91.6% to 57% over six days and phagocyte morphology changes from single cells to aggregates leading to the formation of syncytia-like structures. This process is accelerated in the presence of lipopolysaccharide suggesting that phagocytes are capable of detecting this molecular pattern in culture conditions. Sea urchin immune response proteins, called Sp185/333, are expressed on the surface of a subset of phagocytes and have been associated with syncytia-like structures. We evaluated their expression in cultured phagocytes to determine their possible role in cell aggregation and in the formation of syncytia-like structures. Between 0 and 3 hr, syncytia-like structures were observed in cultures when only ~10% of the cells were positive for Sp185/333 proteins. At 24 hr, ~90% of the nuclei were Sp185/333-positive when all of the phagocytes had aggregated into syncytia-like structures. Consequently, we conclude that the Sp185/333 proteins do not have a major role in initiating the aggregation of cultured phagocytes, however the Sp185/333 proteins are associated with the clustered

  17. Innate Immune Complexity in the Purple Sea Urchin: Diversity of the Sp185/333 System

    Smith, L. Courtney

    2012-01-01

    The California purple sea urchin, Strongylocentrotus purpuratus, is a long-lived echinoderm with a complex and sophisticated innate immune system. There are several large gene families that function in immunity in this species including the Sp185/333 gene family that has ∼50 (±10) members. The family shows intriguing sequence diversity and encodes a broad array of diverse yet similar proteins. The genes have two exons of which the second encodes the mature protein and has repeats and blocks o...

  18. Aryl sulfate formation in sea urchins (Strongylocentrotus droebachiensis) ingesting marine algae (Fucus distichus) containing 2,6-dimethylnapthalene

    The metabolism of tritiated 2,6-dimethylnapthalene (2,6-DMN) was studied in sea urchins (Strongylocentrotus droebachiensis) feeding on marine algae (Fucus distichus). The Fucus accumulated this hydrocarbon from sea water without converting it to metabolites. Most of the tritium accumulated by the sea urchins (e.g., 70.8% after 3 days) from feeding on 2,6-DMN-exposed Fucus was present in the exoskeleton (shell and spines). Moreover, after 3 days feeding, about 90% of the tritium in the total metabolite fraction of the gonads and digestive tract of the sea urchin was present as sulfate derivatives. These metabolites were identified through hydrolysis with aryl sulfatase, followed by thin-layer chromatography of the products. After 14 days of feeding, the tritium associated with the sulfate derivatives decreased in the gonads and digestive tract to 61 and 65%, respectively, of the total metabolite fraction. Hydroxy compounds from sulfatase hydrolysis were chromatographed using multiple elutions with toluene. The hydroxy isomers were separated and the R/sub f/ values were compared to those of pure reference compounds. The data indicated that 80% of the 2,6-dimethylnaphtyl sulfate contained the sulfate on the 1 and/or 3 position of the aromatic ring. Moreover, 6-methyl-2-naphthalenemethanol was not detected, which implies that sea urchins, unlike fish, metabolize alkyl-substituted aromatic hydrocarbons primarily through aromatic ring oxidations

  19. Expression of tryptophan 5-hydroxylase gene during sea urchin neurogenesis and role of serotonergic nervous system in larval behavior.

    Yaguchi, Shunsuke; Katow, Hideki

    2003-11-10

    Tryptophan 5-hydroxylase (TPH) is the rate-limiting enzyme in the biosynthesis of serotonin. cDNA cloning of TPH was carried out, and the occurrence of spatiotemporal transcription of TPH message was examined in larvae of the sea urchin, Hemicentrotus pulcherrimus (HpTPH), with in situ hybridization by using the tyramide signal amplification (TSA) technique and Northern hybridization. Based on deduced amino acids sequence of HpTPH, phylogenetically sea urchin locates at the closest position to vertebrates among invertebrates, and HpTPH had common conserved sequences in a catalytic domain. Initiation of HpTPH transcription occurred at the late gastrula stage exclusively in serotonin cells of apical ganglion (SAG) that was composed of a cluster of HpTPH-positive cells and the negative cells in between. In situ hybridization showed that the mRNA expression pattern was similar to the immunohistochemical localization of serotonin cells reported before (Bisgrove and Burke [1986] Dev. Growth Differ. 28:557-569; Yaguchi et al. [2000] Dev. Growth Differ. 42:479-488). p-Chlorophenylalanine (CPA), an irreversible inhibitor of TPH activity, considerably decreased serotonin content in the serotonin cells, whereas the HpTPH expression pattern and timing, and the extension of neurofibers from SAG cells were apparently unaffected, suggesting CPA exclusively perturbed synthesis of serotonin but not nervous system organization. CPA-treated larvae did not swim, despite the occurrence of ciliary beating in culture chamber, suggesting that proper serotonin synthesis is necessary for normal swimming of the larvae. PMID:14528449

  20. Embryotoxicity of Copper and Zinc in Tropical Sea Urchin Tripneustes gratilla

    Brisneve Edullantes

    2014-06-01

    Full Text Available The study determined the individual toxicity of copper (Cu and zinc (Zn in sea urchin Tripneustes gratilla. Bioassay using inhibitions on fertilization, early cleavage, mid cleavage, late cleavage and blastulation as endpoints involved exposure of viable gametes to Cu and Zn for 0.5, 3, 6, 9 and 12 h, respectively. Inhibitions increased significantly with concentration of Cu and Zn. Probit analysis estimated EC50 values for Cu and Zn, respectively, at 32 and 67 μg·L-1 on fertilization; 31 and 93 μg·L-1 on early cleavage; 43 and 61 μg·L-1 on mid cleavage; 42 and 42 μg·L-1 on late cleavage; and 20 and 44 μg·L-1 on blastulation. Results showed that toxicity of Cu is significantly higher (p<0.05 than that of Zn in all developmental stages, except in late cleavage. Also, the inhibitions elicited by Cu showed sensitivity to life stages. This study provided evidence on heavy metal species-sensitive, concentration-dependent and stage-specif ic inhibitions on embryonic development in T. gratilla to Cu and Zn. Keywords: Embryotoxicity, sea urchin development, individual toxicity, heavy metals

  1. Functional analysis of the sea urchin-derived arylsulfatase (Ars)-element in mammalian cells.

    Watanabe, Satoshi; Watanabe, Sachiko; Sakamoto, Naoaki; Sato, Masahiro; Akasaka, Koji

    2006-09-01

    An insulator is a DNA sequence that has both enhancer-blocking activity, through its ability to modify the influence of neighboring cis-acting elements, and a barrier function that protects a transgene from being silenced by surrounding chromatin. Previously, we isolated and characterized a 582-bp-long element from the sea urchin arylsulfatase gene (Ars). This Ars-element was effective in sea urchin and Drosophila embryos and in plant cells. To investigate Ars-element activity in mammalian cells, we placed the element between the cytomegalovirus enhancer and a luciferase (luc) expression cassette. In contrast to controls lacking the Ars-element, NIH3T3 and 293T cells transfected with the element-containing construct displayed reduced luciferase activities. The Ars-element therefore acts as an enhancer-blocking element in mammalian cells. We assessed the barrier activity of the Ars-element using vectors in which a luc expression cassette was placed between two elements. Transfection experiments demonstrated that luc activity in these vectors was approximately ten-fold higher than in vectors lacking elements. Luc activities were well maintained even after 12 weeks in culture. Our observations demonstrate that the Ars-element has also a barrier activity. These results indicated that the Ars-element act as an insulator in mammalian cells. PMID:16923122

  2. Autonomy in specification of primordial germ cells and their passive translocation in the sea urchin.

    Yajima, Mamiko; Wessel, Gary M

    2012-10-01

    The process of germ line determination involves many conserved genes, yet is highly variable. Echinoderms are positioned at the base of Deuterostomia and are crucial to understanding these evolutionary transitions, yet the mechanism of germ line specification is not known in any member of the phyla. Here we demonstrate that small micromeres (SMics), which are formed at the fifth cell division of the sea urchin embryo, illustrate many typical features of primordial germ cell (PGC) specification. SMics autonomously express germ line genes in isolated culture, including selective Vasa protein accumulation and transcriptional activation of nanos; their descendants are passively displaced towards the animal pole by secondary mesenchyme cells and the elongating archenteron during gastrulation; Cadherin (G form) has an important role in their development and clustering phenotype; and a left/right integration into the future adult anlagen appears to be controlled by a late developmental mechanism. These results suggest that sea urchin SMics share many more characteristics typical of PGCs than previously thought, and imply a more widely conserved system of germ line development among metazoans. PMID:22991443

  3. Recombinant sea urchin vascular endothelial growth factor directs single-crystal growth and branching in vitro.

    Knapp, Regina T; Wu, Ching-Hsuan; Mobilia, Kellen C; Joester, Derk

    2012-10-31

    Biomineralization in sea urchin embryos is a crystal growth process that results in oriented single-crystalline spicules with a complex branching shape and smoothly curving surfaces. Uniquely, the primary mesenchyme cells (PMCs) that construct the endoskeleton can be cultured in vitro. However, in the absence of morphogenetic cues secreted by other cells in the embryo, spicules deposited in PMC culture lack the complex branching behavior observed in the embryo. Herein we demonstrate that recombinant sea urchin vascular endothelial growth factor (rVEGF), a signaling molecule that interacts with a cell-surface receptor, induces spiculogenesis and controls the spicule shape in PMC culture. Depending on the rVEGF concentration, PMCs deposit linear, "h"- and "H"-shaped, or triradiate spicules. Remarkably, the change from linear to triradiate occurs with a switch from bidirectional crystal growth parallel to the calcite c axis to growth along the three a axes. This finding has implications for our understanding of how cells integrate morphogenesis on the multi-micrometer scale with control over lattice orientation on the atomic scale. The PMC model system is uniquely suited to investigate this mechanism and develop biotechnological approaches to single-crystal growth. PMID:23066927

  4. Expression of recombinant sea urchin cellulase SnEG54 using mammalian cell lines.

    Okumura, Fumihiko; Kameda, Hiroyuki; Ojima, Takao; Hatakeyama, Shigetsugu

    2010-05-01

    We previously identified the cellulase SnEG54 from Japanese purple sea urchin Strongylocentrotus nudus, the molecular mass of which is about 54kDa on SDS-PAGE. It is difficult to express and purify a recombinant cellulase protein using bacteria such as Escherichia coli or yeast. In this study, we generated mammalian expression vectors encoding SnEG54 to transiently express SnEG54 in mammalian cells. Both SnEG54 expressed in mammalian cells and SnEG54 released into the culture supernatant showed hydrolytic activity toward carboxymethyl cellulose. By using a retroviral expression system, we also established a mammalian cell line that constitutively produces SnEG54. Unexpectedly, SnEG54 released into the culture medium was not stable, and the peak time showing the highest concentration was approximately 1-2days after seeding into fresh culture media. These findings suggest that non-mammalian sea urchin cellulase can be generated in human cell lines but that recombinant SnEG54 is unstable in culture medium due to an unidentified mechanism. PMID:20381456

  5. Unusual Gene Order and Organization of the Sea Urchin Hox Cluster

    Cameron, R A; Rowen, L; Nesbitt, R; Bloom, S; Rast, J P; Berney, K; Arenas-Mena, C; Martinez, P; Lucas, S; Richardson, P M; Davidson, E H; Peterson, K J; Hood, L

    2005-10-11

    The highly consistent gene order and axial colinear expression patterns found in vertebrate hox gene clusters are less well conserved across the rest of bilaterians. We report the first deuterostome instance of an intact hox cluster with a unique gene order where the paralog groups are not expressed in a sequential manner. The finished sequence from BAC clones from the genome of the sea urchin, Strongylocentrotus purpuratus, reveals a gene order wherein the anterior genes (Hox1, Hox2 and Hox3) lie nearest the posterior genes in the cluster such that the most 3 gene is Hox5. (The gene order is : 5-Hox1, 2, 3, 11/13c, 11/13b, 11/13a, 9/10, 8, 7, 6, 5 - 3). The finished sequence result is corroborated by restriction mapping evidence and BAC-end scaffold analyses. Comparisons with a putative ancestral deuterostome Hox gene cluster suggest that the rearrangements leading to the sea urchin gene order were many and complex.

  6. Unusual Gene Order and Organization of the Sea Urchin HoxCluster

    Richardson, Paul M.; Lucas, Susan; Cameron, R. Andrew; Rowen,Lee; Nesbitt, Ryan; Bloom, Scott; Rast, Jonathan P.; Berney, Kevin; Arenas-Mena, Cesar; Martinez, Pedro; Davidson, Eric H.; Peterson, KevinJ.; Hood, Leroy

    2005-05-10

    The highly consistent gene order and axial colinear expression patterns found in vertebrate hox gene clusters are less well conserved across the rest of bilaterians. We report the first deuterostome instance of an intact hox cluster with a unique gene order where the paralog groups are not expressed in a sequential manner. The finished sequence from BAC clones from the genome of the sea urchin, Strongylocentrotus purpuratus, reveals a gene order wherein the anterior genes (Hox1, Hox2 and Hox3) lie nearest the posterior genes in the cluster such that the most 3' gene is Hox5. (The gene order is : 5'-Hox1,2, 3, 11/13c, 11/13b, '11/13a, 9/10, 8, 7, 6, 5 - 3)'. The finished sequence result is corroborated by restriction mapping evidence and BAC-end scaffold analyses. Comparisons with a putative ancestral deuterostome Hox gene cluster suggest that the rearrangements leading to the sea urchin gene order were many and complex.

  7. Cloning of the sea urchin mitochondrial RNA polymerase and reconstitution of the transcription termination system

    Polosa, Paola Loguercio; Deceglie, Stefania; Falkenberg, Maria; Roberti, Marina; Di Ponzio, Barbara; Gadaleta, Maria Nicola; Cantatore, Palmiro

    2007-01-01

    Termination of transcription is a key process in the regulation of mitochondrial gene expression in animal cells. To investigate transcription termination in sea urchin mitochondria, we cloned the mitochondrial RNA polymerase (mtRNAP) of Paracentrotus lividus and used a recombinant form of the enzyme in a reconstituted transcription system, in the presence of the DNA-binding protein mtDBP. Cloning of mtRNAP was performed by a combination of PCR with degenerate primers and library screening. The enzyme contains 10 phage-like conserved motifs, two pentatricopeptide motifs and a serine-rich stretch. The protein expressed in insect cells supports transcription elongation in a promoter-independent assay. Addition of recombinant mtDBP caused arrest of the transcribing mtRNAP when the enzyme approached the mtDBP-binding site in the direction of transcription of mtDNA l-strand. When the polymerase encountered the protein-binding site in the opposite direction, termination occurred in a protein-independent manner, inside the mtDBP-binding site. Pulse-chase experiments show that mtDBP caused true transcription termination rather than pausing. These data indicate that mtDBP acts as polar termination factor and suggest that transcription termination in sea urchin mitochondria could take place by two alternative modes based on protein-mediated or sequence-dependent mechanisms. PMID:17392338

  8. The potential for cryopreserving larvae of the sea urchin, Evechinus chloroticus.

    Adams, Serean L; Hessian, Paul A; Mladenov, Philip V

    2006-02-01

    Larvae of the sea urchin, Evechinus chloroticus, at varying stages of development, were assessed for their potential to survive cryopreservation. Ethylene glycol (EG) and dimethyl sulphoxide (Me2SO), at concentrations of 1-2 M, were evaluated as cryoprotectants (CPAs) in freezing regimes initially based on methods established for freezing larvae of other sea urchin species. Subsequent work varied cooling rate, holding temperature, holding time, and plunge temperature. Ethylene glycol was less toxic to larvae than Me2SO. However, no larvae survived freezing and thawing in EG. Larvae frozen in Me2SO at the gastrula stage and 4-armed pluteus stage regained motility post-thawing. The most successful freezing regime cooled straws containing larvae in 1.5 M Me2SO from 0 to -35 degrees C at 2.5 degrees C min(-1), held at -35 degrees C for 5 min, then plunged straws into liquid nitrogen. Motility was high 2-4 h post-thawing using this regime but decreased markedly within 24 h. Some 4-armed pluteus larvae that survived beyond this time developed through to metamorphosis and settled. Different Me2SO concentrations and supplementary trehalose did not improve long-term survival. Large variation in post-thaw survival was observed among batches of larvae produced from different females. PMID:16321369

  9. Mechanism of Calcite Co-Orientation in the Sea Urchin Tooth

    Killian, Christopher; Metzler, Rebecca; Gong, Y. U. T.; Olson, Ian; Aizenberg, Joanna; Politi, Yael; Wilt, Fred; Scholl, Andreas; Young, Anthony; Doran, Andrew; Kunz, Martin; Tamura, Nobumichi; Coppersmith, Susan; Gilbert, P. U. P. A.

    2009-12-01

    Sea urchin teeth are remarkable and complex calcite structures, continuously growing at the forming end and self-sharpening at the mature grinding tip. The calcite (CaCO{sub 3}) crystals of tooth components, plates, fibers, and a high-Mg polycrystalline matrix, have highly co-oriented crystallographic axes. This ability to co-orient calcite in a mineralized structure is shared by all echinoderms. However, the physico-chemical mechanism by which calcite crystals become co-oriented in echinoderms remains enigmatic. Here, we show differences in calcite c-axis orientations in the tooth of the purple sea urchin (Strongylocentrotus purpuratus), using high-resolution X-ray photoelectron emission spectromicroscopy (X-PEEM) and microbeam X-ray diffraction ({mu}XRD). All plates share one crystal orientation, propagated through pillar bridges, while fibers and polycrystalline matrix share another orientation. Furthermore, in the forming end of the tooth, we observe that CaCO{sub 3} is present as amorphous calcium carbonate (ACC). We demonstrate that co-orientation of the nanoparticles in the polycrystalline matrix occurs via solid-state secondary nucleation, propagating out from the previously formed fibers and plates, into the amorphous precursor nanoparticles. Because amorphous precursors were observed in diverse biominerals, solid-state secondary nucleation is likely to be a general mechanism for the co-orientation of biomineral components in organisms from different phyla.

  10. A Protocol for Bioinspired Design: A Ground Sampler Based on Sea Urchin Jaws.

    Frank, Michael B; Naleway, Steven E; Wirth, Taylor S; Jung, Jae-Young; Cheung, Charlene L; Loera, Faviola B; Medina, Sandra; Sato, Kirk N; Taylor, Jennifer R A; McKittrick, Joanna

    2016-01-01

    Bioinspired design is an emerging field that takes inspiration from nature to develop high-performance materials and devices. The sea urchin mouthpiece, known as the Aristotle's lantern, is a compelling source of bioinspiration with an intricate network of musculature and calcareous teeth that can scrape, cut, chew food and bore holes into rocky substrates. We describe the bioinspiration process as including animal observation, specimen characterization, device fabrication and mechanism bioexploration. The last step of bioexploration allows for a deeper understanding of the initial biology. The design architecture of the Aristotle's lantern is analyzed with micro-computed tomography and individual teeth are examined with scanning electron microscopy to identify the microstructure. Bioinspired designs are fabricated with a 3D printer, assembled and tested to determine the most efficient lantern opening and closing mechanism. Teeth from the bioinspired lantern design are bioexplored via finite element analysis to explain from a mechanical perspective why keeled tooth structures evolved in the modern sea urchins we observed. This circular approach allows for new conclusions to be drawn from biology and nature. PMID:27166636

  11. Sea urchin-like cobalt-iron phosphide as an active catalyst for oxygen evolution reaction

    Mendoza-Garcia, Adriana; Su, Dong; Sun, Shouheng

    2016-02-01

    Sea urchin-like (CoxFe1-x)2P shows Co/Fe-composition dependent catalysis for oxygen evolution reaction (OER) in 0.1 M KOH. The (Co0.54Fe0.46)2P is the most efficient OER catalyst, reaching 10 mA cm-2 at an overpotential of 0.37 V (vs. RHE). The report offers a new synergistic approach to tune and optimize the electrocatalysis of OER.Sea urchin-like (CoxFe1-x)2P shows Co/Fe-composition dependent catalysis for oxygen evolution reaction (OER) in 0.1 M KOH. The (Co0.54Fe0.46)2P is the most efficient OER catalyst, reaching 10 mA cm-2 at an overpotential of 0.37 V (vs. RHE). The report offers a new synergistic approach to tune and optimize the electrocatalysis of OER. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr08763e

  12. Cadmium induces the expression of specific stress proteins in sea urchin embryos

    Marine organisms are highly sensitive to many environmental stresses, and consequently, the analysis of their bio-molecular responses to different stress agents is very important for the understanding of putative repair mechanisms. Sea urchin embryos represent a simple though significant model system to test how specific stress can simultaneously affect development and protein expression. Here, we used Paracentrotus lividus sea urchin embryos to study the effects of time-dependent continuous exposure to subacute/sublethal cadmium concentrations. We found that, between 15 and 24 h of exposure, the synthesis of a specific set of stress proteins (90, 72-70, 56, 28, and 25 kDa) was induced, with an increase in the rate of synthesis of 72-70 kDa (hsps), 56 kDa (hsp), and 25 kDa, which was dependent on the lengths of treatment. Recovery experiments in which cadmium was removed showed that while stress proteins continued to be synthesized, embryo development was resumed only after short lengths of exposure

  13. Developmental effects of two different copper oxide nanomaterials in sea urchin (Lytechinus pictus) embryos.

    Torres-Duarte, Cristina; Adeleye, Adeyemi S; Pokhrel, Suman; Mädler, Lutz; Keller, Arturo A; Cherr, Gary N

    2016-08-01

    Copper oxide nanomaterials (nano-CuOs) are widely used and can be inadvertently introduced into estuarine and marine environments. We analyzed the effects of different nano-CuOs (a synthesized and a less-pure commercial form), as well as ionic copper (CuSO4) on embryo development in the white sea urchin, a well-known marine model. After 96 h of development with both nano-CuO exposures, we did not detect significant oxidative damage to proteins but did detect decreases in total antioxidant capacity. We show that the physicochemical characteristics of the two nano-CuOs play an essential role in their toxicities. Both nano-CuOs were internalized by embryos and their differential dissolution was the most important toxicological parameter. The synthesized nano-CuO showed greater toxicity (EC50 = 450 ppb of copper) and had increased dissolution (2.5% by weight over 96 h) as compared with the less-pure commercial nano-CuO (EC50 = 5395 ppb of copper, 0.73% dissolution by weight over 96 h). Copper caused specific developmental abnormalities in sea urchin embryos including disruption of the aboral-oral axis as a result in changes to the redox environment caused by dissolution of internalized nano-CuO. Abnormal skeleton formation also occurred. PMID:26643145

  14. Molecular Response to Toxic Diatom-Derived Aldehydes in the Sea Urchin Paracentrotus lividus

    Stefano Varrella

    2014-04-01

    Full Text Available Diatoms are dominant photosynthetic organisms in the world’s oceans and represent a major food source for zooplankton and benthic filter-feeders. However, their beneficial role in sustaining marine food webs has been challenged after the discovery that they produce secondary metabolites, such as polyunsaturated aldehydes (PUAs, which negatively affect the reproductive success of many invertebrates. Here, we report the effects of two common diatom PUAs, heptadienal and octadienal, which have never been tested before at the molecular level, using the sea urchin, Paracentrotus lividus, as a model organism. We show that both PUAs are able to induce teratogenesis (i.e., malformations, as already reported for decadienal, the better-studied PUA of this group. Moreover, post-recovery experiments show that embryos can recover after treatment with all three PUAs, indicating that negative effects depend both on PUA concentrations and the exposure time of the embryos to these metabolites. We also identify the time range during which PUAs exert the greatest effect on sea urchin embryogenesis. Finally, we report the expression levels of thirty one genes (having a key role in a broad range of functional responses, such as stress, development, differentiation, skeletogenesis and detoxification processes in order to identify the common targets affected by PUAs and their correlation with morphological abnormalities. This study opens new perspectives for understanding how marine organisms afford protection from environmental toxicants through an integrated network of genes.

  15. Complete mitochondrial genome of Chilean sea urchin: Loxechinus albus (Camarodonta, Parechinidae).

    Jung, Gila; Lee, Youn-Ho

    2015-01-01

    The complete mitochondrial genome of Chilean sea urchin Loxechinus albus, the single species of the genus Loxechinus, is determined. The circular mitogenome is 15,709 bp in length containing 2 rRNA, 22 tRNA and 13 protein coding genes as well as the control region. The gene order is identical to those of described Camarodonta species. There are 24 bp gene overlaps at 6 locations and 124 bp intergenic spacers at 17 boundaries. The nucleotide composition of the genome is 31.2% A, 22.3% C, 29.7% T, and 16.8% G. The A+T bias (60.9%) is similar to that of P. lividus (60.3%) but slightly higher than those of strongylocentrotid species (58.8-59.8%). The mitogenome sequence of L. albus will provide valuable information on the phylogeny and evolution of the genus Loxechinus in relation to other Camarodonta sea urchins. PMID:24409862

  16. Use of specific glycosidases to probe cellular interactions in the sea urchin embryo.

    Idoni, Brian; Ghazarian, Haike; Metzenberg, Stan; Hutchins-Carroll, Virginia; Oppenheimer, Steven B; Carroll, Edward J

    2010-08-01

    We present an unusual and novel model for initial investigations of a putative role for specifically conformed glycans in cellular interactions. We have used alpha- and ss-amylase and alpha- and ss-glucosidase in dose-response experiments evaluating their effects on archenteron organization using the NIH designated sea urchin embryo model. In quantitative dose-response experiments, we show that defined activity levels of alpha-glucosidase and ss-amylase inhibited archenteron organization in living Lytechinus pictus gastrula embryos, whereas all concentrations of ss-glucosidase and alpha-amylase were without substantial effects on development. Product inhibition studies suggested that the enzymes were acting by their specific glycosidase activities and polyacrylamide gel electrophoresis suggested that there was no detectable protease contamination in the active enzyme samples. The results provide evidence for a role of glycans in sea urchin embryo cellular interactions with special reference to the possible structural conformation of these glycans based on the differential activities of the alpha- and ss-glycosidases. PMID:20435035

  17. Vegetable and synthetic tannins induce hormesis/toxicity in sea urchin early development and in algal growth

    De Nicola, Elena [Italian National Cancer Institute, G. Pascale Foundation, via M. Semmola, I-80131 Naples (Italy); Meric, Suereyya [Department of Civil Engineering, Salerno University, I-84084 Fisciano (Italy); Gallo, Marialuisa [Campania Regional Agency for Environmental Protection (ARPAC), I-80143 Naples (Italy); Iaccarino, Mario [Italian National Cancer Institute, G. Pascale Foundation, via M. Semmola, I-80131 Naples (Italy); Della Rocca, Claudio [Department of Civil Engineering, Salerno University, I-84084 Fisciano (Italy); Lofrano, Giusy [Department of Civil Engineering, Salerno University, I-84084 Fisciano (Italy); Russo, Teresa [Campania Regional Agency for Environmental Protection (ARPAC), I-80143 Naples (Italy); Pagano, Giovanni [Italian National Cancer Institute, G. Pascale Foundation, via M. Semmola, I-80131 Naples (Italy)]. E-mail: gbpagano@tin.it

    2007-03-15

    Mimosa tannin and phenol-based synthetic tannin (syntan) were tested for toxicity to sea urchin (Paracentrotus lividus and Sphaerechinus granularis) early development and to marine algal growth (Dunaliella tertiolecta). Sea urchin embryogenesis was affected by vegetable tannin and syntan water extracts (VTWE and STWE) at levels {>=}1 mg/L. Developmental defects were significantly decreased at VTWE and STWE levels of 0.1 and 0.3 mg/L when control cultures displayed suboptimal quality, i.e. <70% 'viable' (normal or retarded) larvae. Fertilization success of sea urchin sperm was increased up to 0.3 mg/L STWE or VTWE, then was inhibited by increasing tannin levels (1-30 mg/L). Offspring abnormalities, following sperm exposure to VTWE or STWE, showed the same shift from hormesis to toxicity. Cell growth bioassays in D. tertiolecta exposed to VTWE or STWE (0.1-30 mg/L) showed non-linear concentration-related toxicity. Novel criteria are suggested in defining control quality that should reveal hormetic effects. - Vegetable tannin and synthetic tannins were moderately toxic or displayed hormetic effects in sea urchins and in algae. Re-defining control quality is needed for evaluating hormetic effects.

  18. Vegetable and synthetic tannins induce hormesis/toxicity in sea urchin early development and in algal growth

    Mimosa tannin and phenol-based synthetic tannin (syntan) were tested for toxicity to sea urchin (Paracentrotus lividus and Sphaerechinus granularis) early development and to marine algal growth (Dunaliella tertiolecta). Sea urchin embryogenesis was affected by vegetable tannin and syntan water extracts (VTWE and STWE) at levels ≥1 mg/L. Developmental defects were significantly decreased at VTWE and STWE levels of 0.1 and 0.3 mg/L when control cultures displayed suboptimal quality, i.e. <70% 'viable' (normal or retarded) larvae. Fertilization success of sea urchin sperm was increased up to 0.3 mg/L STWE or VTWE, then was inhibited by increasing tannin levels (1-30 mg/L). Offspring abnormalities, following sperm exposure to VTWE or STWE, showed the same shift from hormesis to toxicity. Cell growth bioassays in D. tertiolecta exposed to VTWE or STWE (0.1-30 mg/L) showed non-linear concentration-related toxicity. Novel criteria are suggested in defining control quality that should reveal hormetic effects. - Vegetable tannin and synthetic tannins were moderately toxic or displayed hormetic effects in sea urchins and in algae. Re-defining control quality is needed for evaluating hormetic effects

  19. In the beginning...animal fertilization and sea urchin development.

    Briggs, Elissa; Wessel, Gary M

    2006-12-01

    What I most wished to discover [in my study] was the role that spermatozoids play in fertilization. In order to determine this, I put a droplet of red liquid, and at a small distance, a similar droplet of white liquid in a little trough on the viewing slide of the microscope; then, after covering all of this with a thin strip of glass, I added a drop of sea water. I was then able to watch the spermatozoids advance progressively towards the eggs. Some of [the eggs] were soon encircled by a compact mass of moving corpuscles; others, farther away, only found themselves in contact with a very small number [of sperm]; in both cases, I saw the signs of fertilization. The first apparent effect of this union is the almost immediate appearance of a perfectly transparent envelope that encircles the yolk at a certain distance, which is manifested by the appearance of a circular line. I saw this envelope manifest when in contact with a very small number of spermatozoids (three or four, sometimes even one only). PMID:17070796

  20. A sea urchin lectin, SUL-1, from the Toxopneustid sea urchin induces DC maturation from human monocyte and drives Th1 polarization in vitro.

    Takei, Masao; Nakagawa, Hideyuki

    2006-05-15

    The sea urchin Toxopneustes pileolus belonging to the family Toxopneustidae, they have well-developed globiferous pedicellariae with pharmacologically active substances. We have purified a novel sea urchin lectin-1 (SUL-1) from the large globiferous pedicellariae of T. pileolus. Dendritic cells (DC) are professional APC and play a pivotal role in controlling immune responses. This study investigated whether SUL-1 can drive DC maturation from human immature monocyte-derived DC in vitro. Human monocytes were cultured with GM-CSF and IL-4 for 6 days followed by another 1 day in the presence of SUL-1 or LPS. DC harvested on day 7 were examined using functional assays. The expression levels of CD1a, CD80, CD83, CD86 and HLA-DR as expressed by mean fluorescence intensity (MFI) on DC differentiated from immature DC after culture with 1.0 microg/ml of SUL-1 for 1 day were enhanced and decreased endocytic activity. SUL-1-treated DC also displayed enhanced T cell stimulatory capacity in an MLR, as measured by T cell proliferation. Cell surface expression of CD80, CD83 and CD86 on SUL-1-treated DC was inhibited by anti-DC-SIGN mAb, while anti-DC-SIGN mAb had no influence on allogeneic T cell proliferation by SUL-1-treated DC. DC differentiated with SUL-1 induced the differentiation of naïve T cell towards a helper T cell type 1 (Th1) response at DC/T (1:5) cells ratio depending on IL-12 secretion. In CTL assay, the production of IFN-gamma and 51Cr release on SUL-1-treated DC were more augmented than of immature DC or LPS-treated DC. SUL-1-treated DC expressed CCR7 and had a high migration to MIP-3beta. Intracellular Ca2+ mobilization in SUL-1-treated DC was also induced by MIP-3beta. These results suggest that SUL-1 bindings to DC-SIGN on surface of immature DC may lead to differentiate DC from immature DC. Moreover, it suggests that SUL-1 may be used on DC-based vaccines for cancer immunotherapy. PMID:16197973

  1. A sea urchin lectin, SUL-1, from the Toxopneustid sea urchin induces DC maturation from human monocyte and drives Th1 polarization in vitro

    The sea urchin Toxopneustes pileolus belonging to the family Toxopneustidae, they have well-developed globiferous pedicellariae with pharmacologically active substances. We have purified a novel sea urchin lectin-1 (SUL-1) from the large globiferous pedicellariae of T. pileolus. Dendritic cells (DC) are professional APC and play a pivotal role in controlling immune responses. This study investigated whether SUL-1 can drive DC maturation from human immature monocyte-derived DC in vitro. Human monocytes were cultured with GM-CSF and IL-4 for 6 days followed by another 1 day in the presence of SUL-1 or LPS. DC harvested on day 7 were examined using functional assays. The expression levels of CD1a, CD80, CD83, CD86 and HLA-DR as expressed by mean fluorescence intensity (MFI) on DC differentiated from immature DC after culture with 1.0 μg/ml of SUL-1 for 1 day were enhanced and decreased endocytic activity. SUL-1-treated DC also displayed enhanced T cell stimulatory capacity in an MLR, as measured by T cell proliferation. Cell surface expression of CD80, CD83 and CD86 on SUL-1-treated DC was inhibited by anti-DC-SIGN mAb, while anti-DC-SIGN mAb had no influence on allogeneic T cell proliferation by SUL-1-treated DC. DC differentiated with SUL-1 induced the differentiation of naive T cell towards a helper T cell type 1 (Th1) response at DC/T (1:5) cells ratio depending on IL-12 secretion. In CTL assay, the production of IFN-γ and 51Cr release on SUL-1-treated DC were more augmented than of immature DC or LPS-treated DC. SUL-1-treated DC expressed CCR7 and had a high migration to MIP-3β. Intracellular Ca2+ mobilization in SUL-1-treated DC was also induced by MIP-3β. These results suggest that SUL-1 bindings to DC-SIGN on surface of immature DC may lead to differentiate DC from immature DC. Moreover, it suggests that SUL-1 may be used on DC-based vaccines for cancer immunotherapy

  2. Cloning and characterisation of mtDBP, a DNA-binding protein which binds two distinct regions of sea urchin mitochondrial DNA.

    Loguercio Polosa, P; Roberti, M; Musicco, C; Gadaleta, M N; Quagliariello, E.; Cantatore, P

    1999-01-01

    The cDNA for the sea urchin mitochondrial D-loop-binding protein (mtDBP), a 40 kDa protein which binds two homologous regions of mitochondrial DNA (the D-loop region and the boundary between the oppositely transcribed ND5 and ND6 genes), has been cloned. Four different 3'-untranslated regions have been detected that are related to each other in pairs and do not contain the canonical polyadenylation signal. The in vitro synthesised mature protein (348 amino acids), deprived of the putative sig...

  3. Biogenic acidification reduces sea urchin gonad growth and increases susceptibility of aquaculture to ocean acidification.

    Mos, Benjamin; Byrne, Maria; Dworjanyn, Symon A

    2016-02-01

    Decreasing oceanic pH (ocean acidification) has emphasised the influence of carbonate chemistry on growth of calcifying marine organisms. However, calcifiers can also change carbonate chemistry of surrounding seawater through respiration and calcification, a potential limitation for aquaculture. This study examined how seawater exchange rate and stocking density of the sea urchin Tripneustes gratilla that were reproductively mature affected carbonate system parameters of their culture water, which in turn influenced growth, gonad production and gonad condition. Growth, relative spine length, gonad production and consumption rates were reduced by up to 67% by increased density (9-43 individuals.m(-2)) and reduced exchange rates (3.0-0.3 exchanges.hr(-1)), but survival and food conversion efficiency were unaffected. Analysis of the influence of seawater parameters indicated that reduced pH and calcite saturation state (ΩCa) were the primary factors limiting gonad production and growth. Uptake of bicarbonate and release of respiratory CO2 by T. gratilla changed the carbonate chemistry of surrounding water. Importantly total alkalinity (AT) was reduced, likely due to calcification by the urchins. Low AT limits the capacity of culture water to buffer against acidification. Direct management to counter biogenic acidification will be required to maintain productivity and reproductive output of marine calcifiers, especially as the ocean carbonate system is altered by climate driven ocean acidification. PMID:26595392

  4. Physiological compensation for environmental acidification is limited in the deep-sea urchin Strongylocentrotus fragilis

    J. R. Taylor; C. Lovera; P. J. Whaling; Buck, K.R.; E. F. Pane; Barry, J. P.

    2013-01-01

    Anthropogenic CO2 is now reaching depths over 1000 m in the Eastern Pacific, overlapping the Oxygen Minimum Zone (OMZ). Deep-sea animals – particularly, calcifiers – are suspected to be especially sensitive to environmental acidification associated with global climate change. We have investigated the effects of hypercapnia and hypoxia on the deep-sea urchin Strongylocentrotus fragilis, during two long-term exposure experiments (1 month and 4 month) at three levels of reduced pH at in ...

  5. Social-Ecological Scale Mismatches and the Collapse of the Sea Urchin Fishery in Maine, USA

    Robert L. Vadas

    2012-06-01

    Full Text Available Scale mismatches result in incomplete or ambiguous feedback that impairs the ability to learn and adapt and, ultimately, to sustain natural resources. Our aim is to examine the sea urchin fishery in Maine, USA to better understand the multiscale, social, and biophysical conditions that are important for the design of institutions that might be able to sustain the resource. During the late 1980s and 1990s, the Maine sea urchin fishery was a classic gold rush fishery. In the beginning, the fishery was characterized by an abundant resource with little to no harvesting activity, followed by a period of rapid increase in landings and effort that led to a subsequent and persistent decline in the sea urchin population and a significant reduction in effort. We conducted semistructured interviews with scientists and experienced fishermen to understand the multiscale, social, and biophysical conditions that influence fishermen's harvesting strategies, and the implications of this for the design of institutions for successful resource management. The current co-management system includes an advisory body made up of industry members and scientists it also includes limited entry, and additional input control mechanisms. Many of these measures are implemented at a very broad scale; however, we find that the ecological conditions relevant to the sustainable processes occur at the scale of individual fishing sites or ledges, which is a much finer scale than current management. Therefore, the co-management system maintains an open access system and leaves few incentives for the development of sustainable harvesting strategies among fishermen. The clear suggestion is that the appropriate management system would be one that directly addresses the fine scale ecological and social dynamics within this fishery and gives fishermen property rights over individual ledges (for example, leases. After having briefly reviewed experiences in Canada and Chile, we found that

  6. A Facile Method for Synthesizing TiO2 Sea-Urchin-Like Structures and Their Applications in Solar Energy Harvesting

    WANG Wen-Hui; WANG Wen-Zhong; XU Hong-Xing

    2011-01-01

    We present a new method to prepare TiO2 sea-urchin-like structures,which involves the initial formation of tubular nanostructures and subsequent self-assembly of the nanotubes into micrometer-scale sea-urchin-like structures.We also investigate the important role of alkali aqueous conditions in the preparation of TiO2 sea-urchin-like structures. This facile and cost-effective approach provides a new route for the preparation of self-assembled TiO2 structures.In addition,the performance of the as-synthesized TiO2 sea-urchin-like structures as the active layer of an efficient solar energy harvester is also studied and discussed.

  7. Use of a free ocean CO₂ enrichment (FOCE) system to evaluate the effects of ocean acidification on the foraging behavior of a deep-sea urchin.

    Barry, James P; Lovera, Chris; Buck, Kurt R; Peltzer, Edward T; Taylor, Josi R; Walz, Peter; Whaling, Patrick J; Brewer, Peter G

    2014-08-19

    The influence of ocean acidification in deep-sea ecosystems is poorly understood but is expected to be large because of the presumed low tolerance of deep-sea taxa to environmental change. We used a newly developed deep-sea free ocean CO2 enrichment (dp-FOCE) system to evaluate the potential consequences of future ocean acidification on the feeding behavior of a deep-sea echinoid, the sea urchin, Strongylocentrotus fragilis. The dp-FOCE system simulated future ocean acidification inside an experimental enclosure where observations of feeding behavior were performed. We measured the average movement (speed) of urchins as well as the time required (foraging time) for S. fragilis to approach its preferred food (giant kelp) in the dp-FOCE chamber (-0.46 pH units) and a control chamber (ambient pH). Measurements were performed during each of 4 trials (days -2, 2, 24, 27 after CO2 injection) during the month-long period when groups of urchins were continuously exposed to low pH or control conditions. Although urchin speed did not vary significantly in relation to pH or time exposed, foraging time was significantly longer for urchins in the low-pH treatment. This first deep-sea FOCE experiment demonstrated the utility of the FOCE system approach and suggests that the chemosensory behavior of a deep-sea urchin may be impaired by ocean acidification. PMID:25051305

  8. Estradiol and endocrine disrupting compounds adversely affect development of sea urchin embryos at environmentally relevant concentrations

    Roepke, Troy A. [Bodega Marine Laboratory, University of California, Davis, POB 247, Bodega Bay, CA 94923 (United States); Snyder, Mark J. [Bodega Marine Laboratory, University of California, Davis, POB 247, Bodega Bay, CA 94923 (United States); Cherr, Gary N. [Bodega Marine Laboratory, University of California, Davis, POB 247, Bodega Bay, CA 94923 (United States) and Departments of Environmental Toxicology and Nutrition, One Shields Avenue, University of California, Davis, CA 95616 (United States)]. E-mail: gncherr@ucdavis.edu

    2005-01-26

    Environmental endocrine disrupting compounds (EDCs) are a wide variety of chemicals that typically exert effects, either directly or indirectly, through receptor-mediated processes, thus mimicking endogenous hormones and/or inhibiting normal hormone activities and metabolism. Little is known about the effects of EDCs on echinoderm physiology, reproduction and development. We exposed developing sea urchin embryos (Strongylocentrotus purpuratus and Lytechinus anamesus) to two known EDCs (4-octylphenol (OCT), bisphenol A (BisA)) and to natural and synthetic reproductive hormones (17{beta}-estradiol (E{sub 2}), estrone (E{sub 1}), estriol (E{sub 3}), progesterone (P{sub 4}) and 17{alpha}-ethynylestradiol (EE{sub 2})). In addition, we studied two non-estrogenic EDCs, tributyltin (TBT) and o,p-DDD. Successful development to the pluteus larval stage (96 h post-fertilization) was used to define EDC concentration-response relationships. The order of compound potency based on EC{sub 50} values for a reduction in normal development was as follows: TBT {sub L.anamesus} > OCT > TBT {sub S.{sub p}}{sub urpuratus} >> E{sub 2} > EE{sub 2} > DDD >> BisA > P{sub 4} > E{sub 1} >> E{sub 3}. The effect of TBT was pronounced even at concentrations substantially lower than those commonly reported in heavily contaminated areas, but the response was significantly different in the two model species. Sea urchin embryos were generally more sensitive to estrogenic EDCs and TBT than most other invertebrate larvae. Stage-specific exposure experiments were conducted to determine the most sensitive developmental periods using blastula, gastrula and post-gastrula (pluteus) stages. The stage most sensitive to E{sub 2}, OCT and TBT was the blastula stage with less overall sensitivity in the gastrula stage, regardless of concentration. Selective estrogen receptor modulators (SERMs) were added to the experiments individually and in combination with estrogenic EDCs to interfere with potential receptor

  9. [Embryonic development of the sea urchin after low-temperature preservation].

    Gakhova, E N; Krasts, I V; Naĭdenko, T Kh; Savel'eva, N A; Bessonov, B I

    1988-01-01

    The sea urchin embryos were cooled to -196 degrees by two-step freezing with the use of 1-1.5 M dimethyl sulfoxide as a cryoprotectant. The embryos were equilibrated with the cryoprotectant for 20-30 min at 0 +/- 2 degrees. At -7 degrees ice crystallization was induced and the embryos were cooled to -38-42 degrees at a rate of 6-8 degrees /min. The embryos were then transferred into liquid nitrogen. The embryos were thawed in a water bath at 19 degrees. No less than 90% of the embryos frozen at the stages of blastula, gastrula, or pluteus were capable of recovery and normal development. The length of cryopreservation did not affect the survival of the embryos. PMID:3387042

  10. Hydrodynamism and its influence on the reproductive condition of the edible sea urchin Paracentrotus lividus.

    Gianguzza, Paola; Bonaviri, Chiara; Prato, Ermelinda; Fanelli, Giovanni; Chiantore, Mariachiara; Privitera, Davide; Luzzu, Filippo; Agnetta, Davide

    2013-04-01

    Despite the large body of work published in the last two decades on the reproduction of the sea urchin Paracentrotus lividus, the reproductive aspects linked to hydrodynamic conditions and their influence on gonad production remain poorly understood. The present paper aims to evaluate the effect of hydrodynamism on the reproductive cycle of P. lividus. Variability in the gonadosomatic index (GSI) of P. lividus was estimated seasonally from 2007 to 2008 at two shallow sub-littoral flat basaltic areas at Ustica Island (Western Mediterranean). GSI was higher in the sites characterized by low hydrodynamism than in those with high hydrodynamism. Results also suggest a possible role for hydrodynamism in triggering processes of resource limitation (food shortage), probably by interfering with P. lividus feeding activity. PMID:23333347

  11. Innate immune complexity in the purple sea urchin: diversity of the Sp185/333 system

    L. Courtney Smith

    2012-04-01

    Full Text Available The California purple sea urchin, Strongylocentrotus purpuratus, is a long-lived echinoderm with a complex and sophisticated innate immune system. Several large gene families that function in immunity in this species includes the Sp185/333 gene family with ~50 (±10 members. The family shows intriguing sequence diversity and encodes a broad array of diverse yet similar proteins. The genes have two exons of which the second encodes the mature protein and has repeats and blocks of sequence called elements. Mosaics of element patterns plus SNPs within the elements result in significant sequence diversity among the genes yet maintains similar structure among the members of the family. An Sp185/333-positive BAC insert has a cluster of six, tightly linked Sp185/333 genes that are flanked by GA microsatellites. The sequences between the GA microsatellites are much more similar to each other than are the sequences outside the microsatellites suggesting processes such as gene conversion, recombination, or duplication. However, close linkage does not correspond with greater sequence similarity compared to randomly cloned and sequenced genes that are unlikely to be linked. There are three segmental duplications that are bounded by GAT microsatellites and include three almost identical genes. RNA editing is detectible throughout the messages and putative post-translational modifications to the proteins result in broad arrays of Sp185/333 proteins that differ among individuals. The mature proteins have an N-terminal glycine-rich region, a central RGD motif, and a C-terminal histidine-rich region. The Sp185/333 proteins are localized to the cell surface and are found within vesicles in subsets of polygonal and small phagocytes. The coelomocyte proteome shows full-length and truncated proteins, including some with missense sequence. Current results suggest that both native and a recombinant Sp185/333 protein bind bacteria and are likely important in sea urchin

  12. Design strategies of sea urchin teeth: structure, composition and micromechanical relations to function.

    Wang, R Z; Addadi, L; Weiner, S

    1997-01-01

    The teeth of sea urchins comprise a variety of different structural entities, all of which are composed of magnesium-bearing calcite together with a small amount of organic material. The teeth are worn down continuously, but in such a way that they remain sharp and functional. Here we describe aspects of the structural, compositional and micromechanical properties of the teeth of Paracentrotus lividus using scanning electron microscopy, infrared spectrometry, atomic absorption. X-ray diffraction and microindentation. The S-shaped single crystalline calcitic fibres are one of the main structural elements of the tooth. They extend from the stone part to the keel. The diameter of the fibres increases gradually from less than 1 micron at the stone tip to about 20 microns at the keel end, while their MgCO3 contents decrease from about 13 mol% to about 4.5 mol%. Each fibre is coated by a thin organic sheath and surrounded by polycrystalline calcitic discs containing as much as 35 mol% MgCO3. This structure constitutes a unique kind of gradient fibre-reinforced ceramic matrix composite, whose microhardness and toughness decrease gradually from the stone part to the keel. Primary plates are also important structural elements of the tooth. Each primary plate has a very unusual sandwich-like structure with a calcitic envelope surrounding a thin apparently amorphous CaCO3 layer. This central layer, together with the primary plate/disc interface, improves the toughness of this zone by stopping and blunting cracks. The self-sharpening function of the teeth is believed to result from the combination of the geometrical shape of the main structural elements and their spatial arrangement, the interfacial strength between structural elements, and the hardness gradient extending from the working stone part to the surrounding zones. The sea urchin tooth structure possesses an array of interesting functional design features, some of which may possibly be applicable to materials science

  13. Regulation of membrane fusion and secretory events in the sea urchin embryo

    Membrane fusion and secretory events play a key role in fertilization and early development in the sea urchin embryo. To investigate the mechanism of membrane fusion, the effect of inhibitors of metalloendoprotease activity was studied on two model systems of cell fusion; fertilization and spiculogenesis by primary mesenchyme cells in the embryo. Both the zinc chelator, 1,10-phenanthroline, and peptide metalloprotease substrates were found to inhibit both fertilization and gamete fusion, while peptides that are not substrates of metalloproteases did not affect either process. Primary mesenchyme cells form the larval skeleton in the embryo by deposition of mineral and an organic matrix into a syncytial cavity formed by fusion of filopodia of these cells. Metalloprotease inhibitors were found to inhibit spiculogenesis both in vivo and in cultures of isolated primary mesenchyme cells, and the activity of a metalloprotease of the appropriate specificity was found in the primary mesenchyme cells. These two studies implicate the activity of a metalloprotease in a necessary step in membrane fusion. Following fertilization, exocytosis of the cortical granules results in the formation of the fertilization envelope and the hyaline layer, that surround the developing embryo. The hatching enzyme is secreted by the blastula stage sea urchin embryo, which proteolyzes the fertilization envelope surrounding the embryo, allowing the embryo to hatch. Using an assay that measures 125I-fertilization envelope degradation, the hatching enzyme was identified as a 33 kDa metalloprotease, and was purified by ion-exchange and affinity chromatography from the hatching media of Strongylocentrotus purpuratus embryos. The hatching enzyme showed a substrate preference for only a minor subset of fertilization envelope proteins

  14. Membrane permeability characteristics and osmotic tolerance limits of sea urchin (Evechinus chloroticus) eggs.

    Adams, Serean L; Kleinhans, F W; Mladenov, Philip V; Hessian, Paul A

    2003-08-01

    Development of effective cryopreservation protocols relies on knowledge of the fundamental cryobiological characteristics for a particular cell type. These characteristics include osmotic behaviour, membrane permeability characteristics, and osmotic tolerance limits. Here, we report on measures of these characteristics for unfertilized and fertilised eggs of the sea urchin (Evechinus chloroticus). In NaCl solutions of varying osmolalities, sea urchin eggs behaved as ideal linear osmometers. The osmotically inactive volume (vb) was similar for unfertilized and fertilised eggs, 0.367+/-0.008 (mean+/-SE) and 0.303+/-0.007, respectively. Estimates of water solubility (Lp) and solute permeability (Ps) and their respective activation energies (Ea) for unfertilized and fertilised eggs were determined following exposure to cryoprotectant (CPA) solutions at different temperatures. Irrespective of treatment, fertilised eggs had higher values of Lp and Ps. The presence of a CPA decreased Lp. Among CPAs, solute permeability was highest for propylene glycol followed by dimethyl sulphoxide and then ethylene glycol. Measures of osmotic tolerance limits of the eggs revealed unfertilized eggs were able to tolerate volumetric changes of -20% and +30% of their equilibrium volume; fertilised eggs were able to tolerate changes +/-30%. Using membrane permeability data and osmotic tolerance limits, we established effective methods for loading and unloading CPAs from the eggs. The results of this study establish cryobiological characteristics for E. chloroticus eggs of use for developing an effective cryopreservation protocol. The approach we outline can be readily adapted for determining cryobiological characteristics of other species and cell types, as an aid to successful cryopreservation. PMID:12963407

  15. Neurogenesis in sea urchin embryos and the diversity of deuterostome neurogenic mechanisms.

    Garner, Sarah; Zysk, Ivona; Byrne, Glynis; Kramer, Marabeth; Moller, Daniel; Taylor, Valerie; Burke, Robert D

    2016-01-15

    A single origin to the diverse mechanisms of metazoan neurogenesis is suggested by the involvement of common signaling components and similar classes of transcription factors. However, in many forms we lack details of where neurons arise, patterns of cell division, and specific differentiation pathway components. The sea urchin larval nervous system is composed of an apical organ, which develops from neuroepithelium and functions as a central nervous system, and peripheral neurons, which differentiate in the ciliary band and project axons to the apical organ. To reveal developmental mechanisms of neurogenesis in this basal deuterostome, we developed antibodies to SoxC, SoxB2, ELAV and Brn1/2/4 and used neurons that develop at specific locations to establish a timeline for neurogenesis. Neural progenitors express, in turn, SoxB2, SoxC, and Brn1/2/4, before projecting neurites and expressing ELAV and SynB. Using pulse-chase labeling of cells with a thymidine analog to identify cells in S-phase, we establish that neurons identified by location are in their last mitotic cycle at the time of hatching, and S-phase is coincident with expression of SoxC. The number of cells expressing SoxC and differentiating as neurons is reduced in embryos injected with antisense morpholino oligonucleotides to SoxC, SoxB2 or Six3. Injection of RNA encoding SoxC into eggs does not enhance neurogenesis. In addition, inhibition of FGF receptors (SU5402) or a morpholino to FGFR1 reduces expression of SoxC. These data indicate that there are common features of neurogenesis in deuterostomes, and that sea urchins employ developmental mechanisms that are distinct from other ambulacraria. PMID:26511925

  16. Characterization of the bacterial communities associated with the bald sea urchin disease of the echinoid Paracentrotus lividus.

    Becker, Pierre T; Egea, Emilie; Eeckhaut, Igor

    2008-06-01

    The microbial communities involved in the bald sea urchin disease of the echinoid Paracentrotus lividus are investigated using culture-independent techniques. Lesions of diseased specimens from two locations in France, La Ciotat (Mediterranean Sea) and Morgat (Atlantic Ocean), are examined by Scanning Electron Microscopy (SEM) and the diversity of their microbiota is analysed by Denaturing Gradient Gel Electrophoresis (DGGE) and 16S rRNA gene clones libraries construction. Microscopic observations demonstrated that only the central area of the lesions is invaded by bacteria but not the peripheral zone and the surrounding healthy tissues. Molecular analysis identified at least 24 bacterial genomospecies in bald sea urchin lesions: 5 are Alphaproteobacteria, 10 are Gammaproteobacteria, 8 are CFB bacteria and 1 is a Fusobacteria. Out of them, 4 are observed in both locations while 10 occur only in the Atlantic Ocean and 10 only in the Mediterranean Sea. Gammaproteobacteria are the most represented in clones libraries from both locations, with respectively 65% and 43% of the total clones. CFB and Alphaproteobacteria accounted for the majority of the remaining clones and were detected by DGGE in virtually all samples from both stations. Our results demonstrate that bacterial communities observed on diseased individuals of the same echinoid species but originating from distinct locations are not similar and thus support the hypothesis that bacteria involved in the worldwide echinoid disease commonly called the bald sea urchin disease are opportunistic and not specific. PMID:18191940

  17. Identification of a New Sea Urchin Ets Protein, SpEts4, by Yeast One-Hybrid Screening with the Hatching Enzyme Promoter

    Wei, Zheng; Angerer, Robert C.; Angerer, Lynne M.

    1999-01-01

    We report the use of a yeast one-hybrid system to isolate a transcriptional regulator of the sea urchin embryo hatching enzyme gene, SpHE. This gene is asymmetrically expressed along the animal-vegetal axis of sea urchin embryos under the cell-autonomous control of maternal regulatory activities and therefore provides an excellent entry point for understanding the mechanism that establishes animal-vegetal developmental polarity. To search for transcriptional regulators, we used a fragment of ...

  18. Subtle reproductive impairment through nitric oxide-mediated mechanisms in sea urchins from an area affected by harmful algal blooms

    Migliaccio, Oriana; Castellano, Immacolata; di Cioccio, Davide; Tedeschi, Gabriella; Negri, Armando; Cirino, Paola; Romano, Giovanna; Zingone, Adriana; Palumbo, Anna

    2016-05-01

    The health of the sea urchin Paracentrotus lividus, a key species in the Mediterranean Sea, is menaced by several pressures in coastal environments. Here, we aimed at assessing the reproductive ability of apparently healthy P. lividus population in a marine protected area affected by toxic blooms of Ostreospsis cf. ovata. Wide-ranging analyses were performed in animals collected prior to and during the bloom, as well as at several times thereafter, during the reproductive season. Adults showed a low fertilization rate, along with high nitric oxide (NO) levels in the gonads and the nitration of the major yolk protein toposome, which is an important player in sea urchin development. Serious developmental anomalies were observed in the progeny, which persist several months after the bloom. NO levels were high in the different developmental stages, which also showed variations in the transcription of several genes that were found to be directly or indirectly modulated by NO. These results highlight subtle but important reproductive flaws transmitted from the female gonads to the offspring with the NO involvement. Despite a recovery along time after the bloom, insidious damages can be envisaged in the local sea urchin population, with possible reverberation on the whole benthic system.

  19. Comparison of the disposition of several nitrogen-containing compounds in the sea urchin and other marine invertebrates

    Landrum, P.F.; Crosby, D.G.

    1981-01-01

    1. The disposition of an aromatic amine and three aromatic nitro compounds was investigated in the sea urchin, Strongylocentrotus purpuratus. 2. The sea urchin rapidly eliminated injected compounds. The elimination rate constants decreased in the order p-toluidine greater than p-nitroanisole . p-nitrophenol greater than p-nitrotoluene. The fraction of total injected compound eliminated in 8 h was lowest for p-nitrophenol less than p-toluidine less than p-nitrotoluene less than p-nitroanisole. 3. Biotransformation for the sea urchin was primarily reduction of the nitro group followed by acetylation of the amine. 4. Other animals, starfish (Pisaster ochraceus), sea cucumber (Cucumaria miniata), gum boot chiton (Cryptochiton stelleri) and mussels (Mytilus californianus), injected with p-nitroanisole exhibited a trend toward oxidative biotransformation. 5. Elimination of parent compound was the major pathway for reducing body burden of xenobiotics for the invertebrates studied. 6. p-Toluidine oxidizes during analysis and was thus not suitable for studying biotransformation.

  20. Developmental gene regulatory networks in sea urchins and what we can learn from them [version 1; referees: 3 approved

    Megan L. Martik

    2016-02-01

    Full Text Available Sea urchin embryos begin zygotic transcription shortly after the egg is fertilized.  Throughout the cleavage stages a series of transcription factors are activated and, along with signaling through a number of pathways, at least 15 different cell types are specified by the beginning of gastrulation.  Experimentally, perturbation of contributing transcription factors, signals and receptors and their molecular consequences enabled the assembly of an extensive gene regulatory network model.  That effort, pioneered and led by Eric Davidson and his laboratory, with many additional insights provided by other laboratories, provided the sea urchin community with a valuable resource.  Here we describe the approaches used to enable the assembly of an advanced gene regulatory network model describing molecular diversification during early development.  We then provide examples to show how a relatively advanced authenticated network can be used as a tool for discovery of how diverse developmental mechanisms are controlled and work.

  1. The nucleotide sequences of 5S rRNAs from a sea-cucumber, a starfish and a sea-urchin.

    Ohama, T; Hori, H; Osawa, S

    1983-01-01

    The nucleotide sequences of 5S rRNA from three echinoderms, a sea-cucumber Stichopus oshimae, a starfish Asterina pectinifera and a sea-urchin Hemicentrotus pulcherrimus have been determined. These 5S rRNAs are all 120 nucleotides long. The echinoderm sequences are more related to the sequences of proterostomes animals such as mollusc, annelids and some others (87% identity on average) than to those of vertebrates (82% identity on average).

  2. Augmentative biocontrol in natural marine habitats: persistence, spread and non-target effects of the sea urchin Evechinus chloroticus.

    Javier Atalah

    Full Text Available Augmentative biocontrol aims to control established pest populations through enhancement of their indigenous enemies. To our knowledge, this approach has not been applied at an operational scale in natural marine habitats, in part because of the perceived risk of adverse non-target effects on native ecosystems. In this paper, we focus on the persistence, spread and non-target effects of the sea urchin Evechinus chloroticus when used as biocontrol agent to eradicate an invasive kelp from Fiordland, New Zealand. Rocky reef macrobenthic assemblages were monitored over 17 months in areas where the indigenous algal canopy was either removed or left intact prior to the translocation of a large number of urchins (>50 ind.·m(-2. Urchin densities in treated areas significantly declined ∼9 months after transplant, and began spreading to adjacent sites. At the end of the 17-month study, densities had declined to ∼5 ind.·m(-2. Compared to controls, treatment sites showed persistent shifts from kelp forest to urchin barrens, which were accompanied by significant reductions in taxa richness. Although these non-target effects were pronounced, they were considered to be localised and reversible, and arguably outweigh the irreversible and more profound ecological impacts associated with the establishment of an invasive species in a region of high conservation value. Augmentative biocontrol, used in conjunction with traditional control methods, represents a promising tool for the integrated management of marine pests.

  3. Cis-regulatory control of the nuclear receptor Coup-TF gene in the sea urchin Paracentrotus lividus embryo.

    Lamprini G Kalampoki

    Full Text Available Coup-TF, an orphan member of the nuclear receptor super family, has a fundamental role in the development of metazoan embryos. The study of the gene's regulatory circuit in the sea urchin embryo will facilitate the placement of this transcription factor in the well-studied embryonic Gene Regulatory Network (GRN. The Paracentrotus lividus Coup-TF gene (PlCoup-TF is expressed throughout embryonic development preferentially in the oral ectoderm of the gastrula and the ciliary band of the pluteus stage. Two overlapping λ genomic clones, containing three exons and upstream sequences of PlCoup-TF, were isolated from a genomic library. The transcription initiation site was determined and 5' deletions and individual segments of a 1930 bp upstream region were placed ahead of a GFP reporter cassette and injected into fertilized P.lividus eggs. Module a (-532 to -232, was necessary and sufficient to confer ciliary band expression to the reporter. Comparison of P.lividus and Strongylocentrotus purpuratus upstream Coup-TF sequences, revealed considerable conservation, but none within module a. 5' and internal deletions into module a, defined a smaller region that confers ciliary band specific expression. Putative regulatory cis-acting elements (RE1, RE2 and RE3 within module a, were specifically bound by proteins in sea urchin embryonic nuclear extracts. Site-specific mutagenesis of these elements resulted in loss of reporter activity (RE1 or ectopic expression (RE2, RE3. It is proposed that sea urchin transcription factors, which bind these three regulatory sites, are necessary for spatial and quantitative regulation of the PlCoup-TF gene at pluteus stage sea urchin embryos. These findings lead to the future identification of these factors and to the hierarchical positioning of PlCoup-TF within the embryonic GRN.

  4. "Spiral asters" and cytoplasmic rotation in sea urchin eggs: induction in Strongylocentrotus purpuratus eggs by elevated temperature

    1985-01-01

    "Spiral asters" composed of swirls of subcortical microtubules were recently described in fertilized eggs of the sea urchin Strongylocentrotus purpuratus. In our study, these structures did not occur at culture temperatures below 16 degrees C. When the culture temperature was elevated, however, "spiral asters" routinely appeared during a susceptible period before mitotic prophase when the sperm aster-diaster normally exists. A massive and protracted rotation of the cytoplasm (excluding an imm...

  5. An abundance of Epsilonproteobacteria revealed in the gut microbiome of the laboratory cultured sea urchin, Lytechinus variegatus

    Hakim, Joseph A.; Koo, Hyunmin; Dennis, Lacey N.; Kumar, Ranjit; Ptacek, Travis; Morrow, Casey D.; Lefkowitz, Elliot J.; Powell, Mickie L; Bej, Asim K.; Watts, Stephen A

    2015-01-01

    In this study, we have examined the bacterial community composition of the laboratory cultured sea urchin Lytechinus variegatus gut microbiome and its culture environment using NextGen amplicon sequencing of the V4 segment of the 16S rRNA gene, and downstream bioinformatics tools. Overall, the gut and tank water was dominated by Proteobacteria, whereas the feed consisted of a co-occurrence of Proteobacteria and Firmicutes at a high abundance. The gut tissue represented Epsilonproteobacteria a...

  6. Production, characterization and biocompatibility of marine collagen matrices from an alternative and sustainable source : the sea urchin Paracentrotus lividus

    Cristiano Di Benedetto; Alice Barbaglio; Tiziana Martinello; Valentina Alongi; Dario Fassini; Emanuele Cullorà; Marco Patruno; Francesco Bonasoro; Mario Adolfo Barbosa; Maria Daniela Candia Carnevali; Michela Sugni

    2014-01-01

    Collagen has become a key-molecule in cell culture studies and in the tissue engineering field. Industrially, the principal sources of collagen are calf skin and bones which, however, could be associated to risks of serious disease transmission. In fact, collagen derived from alternative and riskless sources is required, and marine organisms are among the safest and recently exploited ones. Sea urchins possess a circular area of soft tissue surrounding the mouth, the peristomial membrane (PM)...

  7. Augmentative Biocontrol in Natural Marine Habitats: Persistence, Spread and Non-Target Effects of the Sea Urchin Evechinus chloroticus

    Javier Atalah; Hopkins, Grant A.; Forrest, Barrie M.

    2013-01-01

    Augmentative biocontrol aims to control established pest populations through enhancement of their indigenous enemies. To our knowledge, this approach has not been applied at an operational scale in natural marine habitats, in part because of the perceived risk of adverse non-target effects on native ecosystems. In this paper, we focus on the persistence, spread and non-target effects of the sea urchin Evechinus chloroticus when used as biocontrol agent to eradicate an invasive kelp from Fiord...

  8. The Coordination of Centrosome Reproduction with Nuclear Events of the Cell Cycle in the Sea Urchin Zygote

    Hinchcliffe, Edward H.; Cassels, Grizzel O.; Rieder, Conly L.; Sluder, Greenfield

    1998-01-01

    Centrosomes repeatedly reproduce in sea urchin zygotes arrested in S phase, whether cyclin-dependent kinase 1–cyclin B (Cdk1-B) activity remains at prefertilization levels or rises to mitotic values. In contrast, when zygotes are arrested in mitosis using cyclin B Δ-90, anaphase occurs at the normal time, yet centrosomes do not reproduce. Together, these results reveal the cell cycle stage specificity for centrosome reproduction and demonstrate that neither the level nor the cycling of Cdk1-B...

  9. Protein synthesis and the cell cycle: centrosome reproduction in sea urchin eggs is not under translational control

    1990-01-01

    The reproduction, or duplication, of the centrosome is an important event in a cell's preparation for mitosis. We sought to determine if centrosome reproduction is regulated by the synthesis and accumulation of cyclin proteins and/or the synthesis of centrosome-specific proteins at each cell cycle. We continuously treat sea urchin eggs, starting before fertilization, with a combination of emetine and anisomycin, drugs that have separate targets in the protein synthetic pathway. These drugs in...

  10. Effect of Diets Supplemented with Different Sources of Astaxanthin on the Gonad of the Sea Urchin Anthocidaris crassispina

    Jiang-Hai Wang; Jian-Ping Yuan; Juan Peng

    2012-01-01

    The effect of the microalgae Haematococcus pluvialis and Chorella zofingiensis, and synthetic astaxanthin on the gonad of the sea urchin Anthocidaris crassispina was studied. The basal diet was supplemented with H. pluvialis, C. zofingiensis, or synthetic astaxanthin, at two levels of astaxanthin (approximately 400 mg/kg and 100 mg/kg), to obtain t...

  11. Maternal Exposure to Cadmium and Manganese Impairs Reproduction and Progeny Fitness in the Sea Urchin Paracentrotus lividus

    Oriana Migliaccio; Immacolata Castellano; Paola Cirino; Giovanna Romano; Anna Palumbo

    2015-01-01

    Metal contamination represents one of the major sources of pollution in marine environments. In this study we investigated the short-term effects of ecologically relevant cadmium and manganese concentrations (10(-6) and 3.6 x 10(-5) M, respectively) on females of the sea urchin Paracentrotus lividus and their progeny, reared in the absence or presence of the metal. Cadmium is a well-known heavy metal, whereas manganese represents a potential emerging contaminant, resulting from an increased p...

  12. New regulatory circuit controlling spatial and temporal gene expression in the sea urchin embryo oral ectoderm GRN

    Li, Enhu; Materna, Stefan C.; Davidson, Eric H.

    2013-01-01

    The sea urchin oral ectoderm gene regulatory network (GRN) model has increased in complexity as additional genes are added to it, revealing its multiple spatial regulatory state domains. The formation of the oral ectoderm begins with an oral-aboral redox gradient, which is interpreted by the cis-regulatory system of the nodal gene to cause its expression on the oral side of the embryo. Nodal signaling drives cohorts of regulatory genes within the oral ectoderm and its derived subdomains. Acti...

  13. Cis-regulatory control of the nodal gene, initiator of the sea urchin oral ectoderm gene network

    Nam, Jongmin; Su, Yi-Hsien; Lee, Pei Yun; Robertson, Anthony J; Coffman, James A.; Davidson, Eric H.

    2007-01-01

    Expression of the nodal gene initiates the gene regulatory network which establishes the transcriptional specification of the oral ectoderm in the sea urchin embryo. This gene encodes a TGFβ ligand, and in Strongylocentrotus purpuratus its transcription is activated in the presumptive oral ectoderm at about the 30-cell stage. Thereafter Nodal signaling occurs among all cells of the oral ectoderm territory, and nodal expression is required for expression of oral ectoderm regulatory genes. The ...

  14. GRAZING ACTIVITY OF THE SEA URCHIN TRIPNEUSTES GRATILLA IN TROPICAL SEAGRASS BEDS OF BUTON ISLAND, SOUTHEAST SULAWESI, INDONESIA

    Ma’ruf Kasim

    2009-01-01

    The research on grazing activity of a sea urchin (Tripneustes gratilla) in tropical seagrass beds wasconducted in Buton Island. The objectives of the research were to study the grazing activity such as foodpreference, grazing rate and grazing times of T. gratilla in tropical seagrass community. The results of theresearch showed that Thalassia hemprichii and Enhalus acoroides are primary food items of T. gratilla andcontained on average of 55 % and 31 % of the gut contents, respectively. The g...

  15. Production, Characterization and Biocompatibility of Marine Collagen Matrices from an Alternative and Sustainable Source: The Sea Urchin Paracentrotus lividus

    Cristiano Di Benedetto

    2014-09-01

    Full Text Available Collagen has become a key-molecule in cell culture studies and in the tissue engineering field. Industrially, the principal sources of collagen are calf skin and bones which, however, could be associated to risks of serious disease transmission. In fact, collagen derived from alternative and riskless sources is required, and marine organisms are among the safest and recently exploited ones. Sea urchins possess a circular area of soft tissue surrounding the mouth, the peristomial membrane (PM, mainly composed by mammalian-like collagen. The PM of the edible sea urchin Paracentrotus lividus therefore represents a potential unexploited collagen source, easily obtainable as a food industry waste product. Our results demonstrate that it is possible to extract native collagen fibrils from the PM and produce suitable substrates for in vitro system. The obtained matrices appear as a homogeneous fibrillar network (mean fibril diameter 30–400 nm and mesh < 2 μm and display remarkable mechanical properties in term of stiffness (146 ± 48 MPa and viscosity (60.98 ± 52.07 GPa·s. In vitro tests with horse pbMSC show a good biocompatibility in terms of overall cell growth. The obtained results indicate that the sea urchin P. lividus can be a valuable low-cost collagen source for mechanically resistant biomedical devices.

  16. Maintenance of somatic tissue regeneration with age in short- and long-lived species of sea urchins.

    Bodnar, Andrea G; Coffman, James A

    2016-08-01

    Aging in many animals is characterized by a failure to maintain tissue homeostasis and the loss of regenerative capacity. In this study, the ability to maintain tissue homeostasis and regenerative potential was investigated in sea urchins, a novel model to study longevity and negligible senescence. Sea urchins grow indeterminately, regenerate damaged appendages and reproduce throughout their lifespan and yet different species are reported to have very different life expectancies (ranging from 4 to more than 100 years). Quantitative analyses of cell proliferation and apoptosis indicated a low level of cell turnover in tissues of young and old sea urchins of species with different lifespans (Lytechinus variegatus, Strongylocentrotus purpuratus and Mesocentrotus franciscanus). The ability to regenerate damaged tissue was maintained with age as assessed by the regrowth of amputated spines and tube feet (motor and sensory appendages). Expression of genes involved in cell proliferation (pcna), telomere maintenance (tert) and multipotency (seawi and vasa) was maintained with age in somatic tissues. Immunolocalization of the Vasa protein to areas of the tube feet, spines, radial nerve, esophagus and a sub-population of circulating coelomocytes suggests the presence of multipotent cells that may play a role in normal tissue homeostasis and the regenerative potential of external appendages. The results indicate that regenerative potential was maintained with age regardless of lifespan, contrary to the expectation that shorter lived species would invest less in maintenance and repair. PMID:27095483

  17. Expression of the invertebrate sea urchin P16 protein into mammalian MC3T3 osteoblasts transforms and reprograms them into "osteocyte-like" cells.

    Alvares, Keith; Ren, Yinshi; Feng, Jian Q; Veis, Arthur

    2016-01-01

    P16 is an acidic phosphoprotein important in both sea urchin embryonic spicule development and transient mineralization during embryogenesis, syncytium formation, and mineralization in mature urchin tooth. Anti-P16 has been used to localize P16 to the syncytial membranes and the calcite mineral. Specific amino acid sequence motifs in P16 are similar to sequences in DSPP, a protein common to all vertebrate teeth, and crucial for their mineralization. Here, we examine the effect of P16 on vertebrate fibroblastic NIH3T3 cells and osteoblastic MC3T3 cells. Transfection of NIH3T3 cells with P16 cDNA resulted in profound changes in the morphology of the cells. In culture, the transfected cells sent out long processes that contacted processes from neighboring cells forming networks or syncytia. There was a similar change in morphology in cultured osteoblastic MC3T3 cells. In addition, the MC3T3 developed numerous dendrites as found in osteocytes. Importantly, there was also a change in the expression of the osteoblast and osteocyte specific genes. MC3T3 cells transfected with P16 showed an 18-fold increase in expression of the osteocyte specific Dentin matrix protein (DMP1) gene, accompanied by decreased expression of osteoblast specific genes: Bone sialoprotein (BSP), osteocalcin (OCN), and β-catenin decreased by 70%, 64%, and 68 %, respectively. Thus, invertebrate urchin P16 with no previously known analog in vertebrates was able to induce changes in both cell morphology and gene expression, converting vertebrate-derived osteoblast-like precursor cells to an "osteocyte-like" phenotype, an important process in bone biology. The mechanisms involved are presently under study. PMID:26581835

  18. Innate immune complexity in the purple sea urchin: diversity of the sp185/333 system.

    Smith, L Courtney

    2012-01-01

    The California purple sea urchin, Strongylocentrotus purpuratus, is a long-lived echinoderm with a complex and sophisticated innate immune system. There are several large gene families that function in immunity in this species including the Sp185/333 gene family that has ∼50 (±10) members. The family shows intriguing sequence diversity and encodes a broad array of diverse yet similar proteins. The genes have two exons of which the second encodes the mature protein and has repeats and blocks of sequence called elements. Mosaics of element patterns plus single nucleotide polymorphisms-based variants of the elements result in significant sequence diversity among the genes yet maintains similar structure among the members of the family. Sequence of a bacterial artificial chromosome insert shows a cluster of six, tightly linked Sp185/333 genes that are flanked by GA microsatellites. The sequences between the GA microsatellites in which the Sp185/333 genes and flanking regions are located, are much more similar to each other than are the sequences outside the microsatellites suggesting processes such as gene conversion, recombination, or duplication. However, close linkage does not correspond with greater sequence similarity compared to randomly cloned and sequenced genes that are unlikely to be linked. There are three segmental duplications that are bounded by GAT microsatellites and include three almost identical genes plus flanking regions. RNA editing is detectible throughout the mRNAs based on comparisons to the genes, which, in combination with putative post-translational modifications to the proteins, results in broad arrays of Sp185/333 proteins that differ among individuals. The mature proteins have an N-terminal glycine-rich region, a central RGD motif, and a C-terminal histidine-rich region. The Sp185/333 proteins are localized to the cell surface and are found within vesicles in subsets of polygonal and small phagocytes. The coelomocyte proteome shows full

  19. Development of the GABA-ergic signaling system and its role in larval swimming in sea urchin.

    Katow, Hideki; Abe, Kouki; Katow, Tomoko; Zamani, Alemeh; Abe, Hirokazu

    2013-05-01

    The present study aimed to elucidate the development and γ-amino butyric acid (GABA)-ergic regulation of larval swimming in the sea urchin Hemicentrotus pulcherrimus by cloning glutamate decarboxylase (Hp-gad), GABAA receptor (Hp-gabrA) and GABAA receptor-associated protein (Hp-gabarap), and by performing immunohistochemistry. The regulation of larval swimming was increasingly dependent on the GABAergic system, which was active from the 2 days post-fertilization (d.p.f.) pluteus stage onwards. GABA-immunoreactive cells were detected as a subpopulation of secondary mesenchyme cells during gastrulation and eventually constituted the ciliary band and a subpopulation of blastocoelar cells during the pluteus stage. Hp-gad transcription was detected by RT-PCR during the period when Hp-Gad-positive cells were seen as a subpopulation of blastocoelar cells and on the apical side of the ciliary band from the 2 d.p.f. pluteus stage. Consistent with these observations, inhibition of GAD with 3-mercaptopropioninc acid inhibited GABA immunoreactivity and larval swimming dose dependently. Hp-gabrA amplimers were detected weakly in unfertilized eggs and 4 d.p.f. plutei but strongly from fertilized eggs to 2 d.p.f. plutei, and Hp-GabrA, together with GABA, was localized at the ciliary band in association with dopamine receptor D1 from the two-arm pluteus stage. Hp-gabarap transcription and protein expression were detected from the swimming blastula stage. Inhibition of the GABAA receptor by bicuculline inhibited larval swimming dose dependently. Inhibition of larval swimming by either 3-mercaptopropionic acid or bicuculline was more severe in older larvae (17 and 34 d.p.f. plutei) than in younger ones (1 d.p.f. prism larvae). PMID:23307803

  20. Physiological effects of environmental acidification in the deep-sea urchin Strongylocentrotus fragilis

    J. R. Taylor; C. Lovera; P. J. Whaling; Buck, K.R.; E. F. Pane; Barry, J. P.

    2014-01-01

    Anthropogenic CO2 is now reaching depths over 1000 m in the Eastern Pacific, overlapping the Oxygen Minimum Zone (OMZ). Deep-sea animals are suspected to be especially sensitive to environmental acidification associated with global climate change. We have investigated the effects of elevated pCO2 and variable O2 on the deep-sea urchin Strongylocentrotus fragilis, a species whose range of 200–1200 m depth includes the OMZ and spans a pCO2 range of approx. 600–1200 μatm (ap...

  1. Production, characterization and biocompatibility of marine collagen matrices from an alternative and sustainable source: the sea urchin Paracentrotus lividus.

    Benedetto, Cristiano Di; Barbaglio, Alice; Martinello, Tiziana; Alongi, Valentina; Fassini, Dario; Cullorà, Emanuele; Patruno, Marco; Bonasoro, Francesco; Barbosa, Mario Adolfo; Carnevali, Maria Daniela Candia; Sugni, Michela

    2014-09-01

    Collagen has become a key-molecule in cell culture studies and in the tissue engineering field. Industrially, the principal sources of collagen are calf skin and bones which, however, could be associated to risks of serious disease transmission. In fact, collagen derived from alternative and riskless sources is required, and marine organisms are among the safest and recently exploited ones. Sea urchins possess a circular area of soft tissue surrounding the mouth, the peristomial membrane (PM), mainly composed by mammalian-like collagen. The PM of the edible sea urchin Paracentrotus lividus therefore represents a potential unexploited collagen source, easily obtainable as a food industry waste product. Our results demonstrate that it is possible to extract native collagen fibrils from the PM and produce suitable substrates for in vitro system. The obtained matrices appear as a homogeneous fibrillar network (mean fibril diameter 30-400 nm and mesh urchin P. lividus can be a valuable low-cost collagen source for mechanically resistant biomedical devices. PMID:25255130

  2. Assessment of the toxic effect exerted by fluorescent pseudomonads on embryos and larvae of the sea urchin Strongylocentrotus nudus.

    Beleneva, I A; Shamshurina, E V; Eliseikina, M G

    2015-05-01

    Strains of bacteria capable of growing on artificial culture media were isolated from the fouling of brass plates submerged in Nha Trang Bay, South China Sea, and from tissues of the seastar Distolasterias nipon, caught in Peter the Great Bay, Sea of Japan. According to the complex of data of genetic and physiological/biochemical analyzes, two strains of cultivated bacteria were identified by us as the species Pseudomonas aeruginosa, two strains as Pseudomonas fluorescens, and one strain as Ruegeria sp. It was shown that the cultivated strains of P. aeruginosa released exotoxins, particularly phenazine pigments, into the environment. Production of the toxins did not depend on presence of a target organism in the system and was aimed at regulation of interactions in the microbial community. The toxicity of the studied natural isolates of fluorescent pseudomonads was analyzed by using embryos and larvae of the sea urchin Strongylocentrotus nudus, which are the sensitive and dynamic toxicological sea-urchin embryo test (SET) system. As was established, exotoxins produced by the strains of P. aeruginosa inhibit activity of cilia in sea urchin larvae, as well as disturb processes of cell differentiation in embryos and larvae. Their toxic influence is accompanied by disturbances of protein synthesis and the disruptions of cytoskeleton in the course of zygote cleavage and larval development. Unlike P. aeruginosa, the strains of P. fluorescens and Ruegeria sp. did not exert the toxic effect on SET. The obtained data allow considering objects of the environment as the natural reservoir of opportunistic microorganisms posing a potential threat to human, whereas the use of SET for determination of toxicity of isolated bacteria provides an opportunity to study the mechanisms of their interactions with organisms in marine ecosystems. PMID:25728358

  3. Maternal Exposure to Cadmium and Manganese Impairs Reproduction and Progeny Fitness in the Sea Urchin Paracentrotus lividus

    Migliaccio, Oriana; Castellano, Immacolata; Cirino, Paola; Romano, Giovanna; Palumbo, Anna

    2015-01-01

    Metal contamination represents one of the major sources of pollution in marine environments. In this study we investigated the short-term effects of ecologically relevant cadmium and manganese concentrations (10-6 and 3.6 x 10-5 M, respectively) on females of the sea urchin Paracentrotus lividus and their progeny, reared in the absence or presence of the metal. Cadmium is a well-known heavy metal, whereas manganese represents a potential emerging contaminant, resulting from an increased production of manganese-containing compounds. The effects of these agents were examined on both P. lividus adults and their offspring following reproductive state, morphology of embryos, nitric oxide (NO) production and differential gene expression. Here, we demonstrated that both metals differentially impaired the fertilization processes of the treated female sea urchins, causing modifications in the reproductive state and also affecting NO production in the ovaries. A detailed analysis of the progeny showed a high percentage of abnormal embryos, associated to an increase in the endogenous NO levels and variations in the transcriptional expression of several genes involved in stress response, skeletogenesis, detoxification, multi drug efflux processes and NO production. Moreover, we found significant differences in the progeny from females exposed to metals and reared in metal-containing sea water compared to embryos reared in non-contaminated sea water. Overall, these results greatly expanded previous studies on the toxic effects of metals on P. lividus and provided new insights into the molecular events induced in the progeny of sea urchins exposed to metals. PMID:26125595

  4. Maternal Exposure to Cadmium and Manganese Impairs Reproduction and Progeny Fitness in the Sea Urchin Paracentrotus lividus.

    Oriana Migliaccio

    Full Text Available Metal contamination represents one of the major sources of pollution in marine environments. In this study we investigated the short-term effects of ecologically relevant cadmium and manganese concentrations (10(-6 and 3.6 x 10(-5 M, respectively on females of the sea urchin Paracentrotus lividus and their progeny, reared in the absence or presence of the metal. Cadmium is a well-known heavy metal, whereas manganese represents a potential emerging contaminant, resulting from an increased production of manganese-containing compounds. The effects of these agents were examined on both P. lividus adults and their offspring following reproductive state, morphology of embryos, nitric oxide (NO production and differential gene expression. Here, we demonstrated that both metals differentially impaired the fertilization processes of the treated female sea urchins, causing modifications in the reproductive state and also affecting NO production in the ovaries. A detailed analysis of the progeny showed a high percentage of abnormal embryos, associated to an increase in the endogenous NO levels and variations in the transcriptional expression of several genes involved in stress response, skeletogenesis, detoxification, multi drug efflux processes and NO production. Moreover, we found significant differences in the progeny from females exposed to metals and reared in metal-containing sea water compared to embryos reared in non-contaminated sea water. Overall, these results greatly expanded previous studies on the toxic effects of metals on P. lividus and provided new insights into the molecular events induced in the progeny of sea urchins exposed to metals.

  5. Effects of warm acclimation on physiology and gonad development in the sea urchin Evechinus chloroticus.

    Delorme, Natalí J; Sewell, Mary A

    2016-08-01

    The physiology of the New Zealand sea urchin Evechinus chloroticus was evaluated through feeding, respiration, growth and gonad growth in adult animals acclimated for 90days at 18°C (annual mean temperature) and 24°C (ambient summer temperature (21°C) +3°C). Measured parameters with representative rates of assimilation efficiency were used to calculate scope for growth (SfG) for each treatment. All physiological parameters were negatively affected at 24°C, showing a decrease in feeding rate which coincided with negative growth and gonad development at the end of the acclimation period, and a decrease in respiration rate suggesting metabolic depression. Histology of gonad samples after the acclimation period also showed no gametic material in animals acclimated at 24°C. All animals acclimated at 24°C had negative growth, differing from the calculated SfG which indicated that the animals had sufficient energy for production. The results suggest that calculated SfG in echinoderms should be used together with actual measurements of growth in individuals as, by itself, SfG may underestimate the actual effect of ocean warming when animals are exposed to stressful conditions. Overall, considering the total loss of reproductive output observed in E. chloroticus at higher temperatures, an increase in seawater temperature could dramatically influence the persistence of northern populations of this species, leading to flow-on effects in the subtidal ecosystem. PMID:27043875

  6. Ovothiol isolated from sea urchin oocytes induces autophagy in the Hep-G2 cell line.

    Russo, Gian Luigi; Russo, Maria; Castellano, Immacolata; Napolitano, Alessandra; Palumbo, Anna

    2014-07-01

    Ovothiols are histidine-derived thiols isolated from sea urchin eggs, where they play a key role in the protection of cells toward the oxidative burst associated with fertilization by controlling the cellular redox balance and recycling oxidized glutathione. In this study, we show that treatment of a human liver carcinoma cell line, Hep-G2, with ovothiol A, isolated from Paracentrotus lividus oocytes, results in a decrease of cell proliferation in a dose-dependent manner. The activation of an autophagic process is revealed by phase contrast and fluorescence microscopy, together with the expression of the specific autophagic molecular markers, LC3 II and Beclin-1. The effect of ovothiol is not due to its antioxidant capacity or to hydrogen peroxide generation. The concentration of ovothiol A in the culture media, as monitored by HPLC analysis, decreased by about 24% within 30 min from treatment. The proliferation of normal human embryonic lung cells is not affected by ovothiol A. These results hint at ovothiol as a promising bioactive molecule from marine organisms able to inhibit cell proliferation in cancer cells. PMID:25003791

  7. Ovothiol Isolated from Sea Urchin Oocytes Induces Autophagy in the Hep-G2 Cell Line

    Gian Luigi Russo

    2014-07-01

    Full Text Available Ovothiols are histidine-derived thiols isolated from sea urchin eggs, where they play a key role in the protection of cells toward the oxidative burst associated with fertilization by controlling the cellular redox balance and recycling oxidized glutathione. In this study, we show that treatment of a human liver carcinoma cell line, Hep-G2, with ovothiol A, isolated from Paracentrotus lividus oocytes, results in a decrease of cell proliferation in a dose-dependent manner. The activation of an autophagic process is revealed by phase contrast and fluorescence microscopy, together with the expression of the specific autophagic molecular markers, LC3 II and Beclin-1. The effect of ovothiol is not due to its antioxidant capacity or to hydrogen peroxide generation. The concentration of ovothiol A in the culture media, as monitored by HPLC analysis, decreased by about 24% within 30 min from treatment. The proliferation of normal human embryonic lung cells is not affected by ovothiol A. These results hint at ovothiol as a promising bioactive molecule from marine organisms able to inhibit cell proliferation in cancer cells.

  8. UVB radiation prevents skeleton growth and stimulates the expression of stress markers in sea urchin embryos

    Ozone depletion results in an increased flux of biologically damaging radiations reaching the earth. Although ultraviolet (UV) penetration is attenuated by the seawater, harmful effects can be still observed at low depths where sea urchin embryos are living. We have used Paracentrotus lividus embryos to study the impacts of UV radiation on their development. Blastula cultures were exposed to different doses of UVB (312 nm) radiations and the resulting endpoint effects were evaluated in terms of embryonic morphological abnormalities, variations in specific gene expression, and changes in the levels of stress proteins. We found that embryos were moderately sensitive to 50 J/m2 UVB radiation; an increase in the number of developmentally delayed and malformed embryos was detected when increasing doses, up to 1000 J/m2, were used. Major developmental defects, observed 24 and 48 h after exposure, consisted in the failure of skeleton elongation and patterning. Accordingly, we found a reduction in the number of primary mesenchyme cells that expressed Pl-SM30, a gene coding for one of the specific matrix proteins of the skeleton. The morphological effects observed 1, 24, and 48 h after exposure were correlated with a dose-dependent increase in the level and in the activation of two recognized stress markers, namely hsp70 and p38 MAPk, respectively, consistent with their role in mediating cellular response to stress and suggesting a function in embryo survival

  9. Sea urchin arylsulfatase insulator exerts its anti-silencing effect without interacting with the nuclear matrix.

    Hino, Shinjiro; Akasaka, Koji; Matsuoka, Masao

    2006-03-17

    Chromatin insulators have been shown to stabilize transgene expression. Although insulators have been suggested to regulate the subcellular localization of chromosomes, it is still unclear whether this property is important for their anti-silencing activity. To investigate the underlying mechanisms governing the anti-silencing function of insulators, we studied the association of sea urchin arylsulfatase insulator (ArsI) with the nuclear matrix, which is a key component of the subnuclear localization of the genome. ArsI did not potentiate the nuclear matrix association with the transgene, even though it showed strong anti-silencing activity. This observation was in clear contrast to the results of the experiment using a human interferon-beta scaffold attachment region, in which the anti-silencing effect coincided with the enhanced matrix association. Chromatin immunoprecipitation analyses suggested that the absence of the matrix binding by ArsI was due to a lack of its binding to CCCTC-binding factor (CTCF), a protein known to be associated with matrix binding by chicken beta-globin insulator. Furthermore, ArsI maintained the nucleosome occupancy within the transgene at a constant level during long-term culture, although ArsI itself was not a nucleosome-excluding sequence. Taken together, these results suggest that this insulator exerts its anti-silencing activity by counteracting silencing-associated factors to maintain local chromatin environment, rather than by remodeling the subnuclear localization of the transgene locus. PMID:16426632

  10. Developmental expression of a cell surface protein involved in sea urchin skeleton formation

    The authors have previously used a monoclonal antibody (1223) to identify a 130 Kd cell surface protein involved in skeleton formation is sea urchin embryos. In the current study the authors have examined the expression of the 1223 antigen over the course of development of embryos of two species, Strongylocentrotus purpuratus and Lytechinus pictus. The 130 Kd protein is detected in S. purp eggs on immunoblots. Labeling with [3H] leucine and immunoaffinity chromatography show that it also is synthesized shortly after fertilization. Immunofluroescence reveals that at this early stage the 1223 antigen is uniformly distributed on all of the cells. Synthesis decreases to a minimum by the time of hatching (18 h), as does the total amount of antigen present in the embryo. A second period of synthesis commences at the mesenchyme blastula stage, when the spicule-forming primary mesenchyme cells (PMCs) have appeared. During this later stage, synthesis and cell surface expression are restricted to the PMCs. In contrast to S. purp., in L. pictus the 130 Kd protein does not appear until the PMCs are formed. Hybrid embryos demonstrate a pattern of expression of the maternal species. These results suggest that early expression of 1223 antigen in S. purp. is due to utilization of maternal transcripts present in the egg. In both species later expression in PMCs appears to be the result of cell-type specific synthesis, perhaps encoded by embryonic transcripts

  11. Central Spindle Self-Organization and Cytokinesis in Artificially Activated Sea Urchin Eggs.

    Henson, John H; Buckley, Mary W; Yeterian, Mesrob; Weeks, Richard M; Simerly, Calvin R; Shuster, Charles B

    2016-04-01

    The ability of microtubules of the mitotic apparatus to control the positioning and initiation of the cleavage furrow during cytokinesis was first established from studies on early echinoderm embryos. However, the identity of the microtubule population that imparts cytokinetic signaling is unclear. The two main--and not necessarily mutually exclusive--candidates are the central spindle and the astral rays. In the present study, we examined cytokinesis in ammonia-activated sea urchin eggs, which lack paternally derived centrosomes and undergo mitosis mediated by unusual anastral, bipolar mini-spindles. Live cell imaging and immunolabeling for microtubules and the centralspindlin constituent and kinesin-related protein, MKLP1, demonstrated that furrowing in ammonia-activated eggs was associated with aligned arrays of centralspindlin-linked, opposed bundles of antiparallel microtubules. These autonomous, zipper-like arrays were not associated with a mitotic apparatus, but did possess characteristics similar to the central spindle region of control, fertilized embryos. Our results highlight the self-organizing nature of the central spindle region and its ability to induce cytokinesis-like furrowing, even in the absence of a complete mitotic apparatus. PMID:27132131

  12. Toxicity of binary mixtures of oil fractions to sea urchin embryos.

    Rial, Diego; Vázquez, José A; Menduiña, Araceli; García, Ana M; González, M Pilar; Mirón, Jesús; Murado, Miguel A

    2013-12-15

    The assumption of additive toxicity for oil compounds is related to a narcotic mode of action. However, the joint toxicity of oil fractions has not been fully investigated. A fractionation of Maya crude oil into aliphatics, aromatics and polars was performed, fractions were dissolved in dimethyl sulfoxide (DMSO) and subsequently toxicity of single fractions and binary mixtures was assessed using the sea urchin embryo test. The descriptive ability of Concentration Addition (CA), Independent Action (IA) and modifications of both models for describing the joint toxicity of mixtures has also been evaluated. The hydrocarbon content extractable with dichloromethane of the fractions dissolved in DMSO was: 12.0 ± 1.8 mg mL(-1), 39.0 ± 0.5 mg mL(-1) and 20.5 ± 2.5 mg mL(-1) for aliphatics, aromatics and polars, respectively. The toxicity of the extracts in DMSO of the fractions as EC50 (μLL(-1)) was: aliphatics (165.8-242.3)binary mixtures (aliphatics-aromatics, aromatics-polars) greater than the IA (aliphatics-polars) according to the Akaike Information Criterion, so CA was considered a better option than IA to explain the joint toxicity of oil fractions. In addition, synergistic or antagonistic effects were not observed. PMID:24231335

  13. Complete mitogenome of the edible sea urchin Loxechinus albus: genetic structure and comparative genomics within Echinozoa.

    Cea, Graciela; Gaitán-Espitia, Juan Diego; Cárdenas, Leyla

    2015-06-01

    The edible Chilean red sea urchin, Loxechinus albus, is the only species of its genus and endemic to the Southeastern Pacific. In this study, we reconstructed the mitochondrial genome of L. albus by combining Sanger and pyrosequencing technologies. The mtDNA genome had a length of 15,737 bp and encoded the same 13 protein-coding genes, 22 transfer RNA genes, and two ribosomal RNA genes as other animal mtDNAs. The size of this mitogenome was similar to those of other Echinodermata species. Structural comparisons showed a highly conserved structure, composition, and gene order within Echinoidea and Holothuroidea, and nearly identical gene organization to that found in Asteroidea and Crinoidea, with the majority of differences explained by the inversions of some tRNA genes. Phylogenetic reconstruction supported the monophyly of Echinozoa and recovered the monophyletic relationship of Holothuroidea and Echinoidea. Within Holothuroidea, Bayesian and maximum likelihood analyses recovered a sister-group relationship between Dendrochirotacea and Aspidochirotida. Similarly within Echinoidea, these analyses revealed that L. albus was closely related to Paracentrotus lividus, both being part of a sister group to Strongylocentrotidae and Echinometridae. In addition, two major clades were found within Strongylocentrotidae. One of these clades comprised all of the representative species Strongylocentrotus and Hemicentrotus, whereas the other included species of Mesocentrotus and Pseudocentrotus. PMID:25433433

  14. pH-induced changes in mitotic and developmental patterns in sea urchin embryogenesis. I. Exposure of embryos.

    Pagano, G; Cipollaro, M; Corsale, G; Esposito, A; Ragucci, E; Giordano, G G

    1985-01-01

    The effects of different pH conditions have been investigated on sea urchin larval development following exposure of embryos to controlled, though changing, decreases or increases of seawater pH. The pH of filtered natural seawater was initially adjusted with 1 N HCl of 1 N KOH and then was altered back to its normal values (8.0-8.2) by the exchange with atmospheric CO2 and subsequent carbonic acid equilibrium. During cultures, pH was regularly monitored. When developing embryos were reared in different pH conditions, larval differentiation was sharply affected by an apparently moderate pH decrease, such as 0.5 pH units. However, even pH decreases as small as 0.2 pH units from the normal value showed reproducible damage to embryogenesis. This damage appeared to be early and irreversible, since the exposure of cleaving embryos resulted in more severe developmental defects than exposure of posthatching blastulae. Moreover, mitotic abnormalities were observed following early exposure of embryos to decreased pH. Increased pH, up to 8.6 (approximately 0.5 pH units above normal value), failed to exert any adverse effect on subsequent development. Moreover, an initial pH increase (8.5-8.7) resulted in the final adjustment of culture pH to 8.1-8.2, thus providing optimal conditions for rearing embryos. Two attempts to stabilize culture pH were performed by decreasing gaseous exchanges or by using Tris as a buffering agent. Both approaches appeared to be impractical, thus ruling out any further attempts. The results point out the hazards of acid contamination in restricted bodies of seawater, leading to apparently "moderate" decreases in pH, which can result in severe damage to some marine organisms, both adult and larval forms. PMID:2859664

  15. Do hatchery-reared sea urchins pose a threat to genetic diversity in wild populations?

    Segovia-Viadero, M; Serrão, E A; Canteras-Jordana, J C; Gonzalez-Wangüemert, M

    2016-04-01

    In salmonids, the release of hatchery-reared fish has been shown to cause irreversible genetic impacts on wild populations. However, although responsible practices for producing and releasing genetically diverse, hatchery-reared juveniles have been published widely, they are rarely implemented. Here, we investigated genetic differences between wild and early-generation hatchery-reared populations of the purple sea urchin Paracentrotus lividus (a commercially important species in Europe) to assess whether hatcheries were able to maintain natural levels of genetic diversity. To test the hypothesis that hatchery rearing would cause bottleneck effects (that is, a substantial reduction in genetic diversity and differentiation from wild populations), we compared the levels and patterns of genetic variation between two hatcheries and four nearby wild populations, using samples from both Spain and Ireland. We found that hatchery-reared populations were less diverse and had diverged significantly from the wild populations, with a very small effective population size and a high degree of relatedness between individuals. These results raise a number of concerns about the genetic impacts of their release into wild populations, particularly when such a degree of differentiation can occur in a single generation of hatchery rearing. Consequently, we suggest that caution should be taken when using hatchery-reared individuals to augment fisheries, even for marine species with high dispersal capacity, and we provide some recommendations to improve hatchery rearing and release practices. Our results further highlight the need to consider the genetic risks of releasing hatchery-reared juveniles into the wild during the establishment of restocking, stock enhancement and sea ranching programs. PMID:26758187

  16. Habitat traits and patterns of abundance of the purple sea urchin, Paracentrotus lividus (Lamarck, 1816), at multiple scales along the north Portuguese coast

    Domínguez, Rula; Domínguez Godino, Jorge; Freitas, Cristiano; Machado, Inês; Bertocci, Iacopo

    2015-03-01

    Spatial and temporal patterns of abundance and distribution of sea urchins (Paracentrotus lividus) from intertidal rockpools of the north Portuguese coast were examined in relation to physical (surface, altitude, depth, topographic complexity and exposure) and biological (substrate cover by dominant organisms) habitat traits. The methodology was based on a multi-factorial design where the total number and the abundance of urchins in each of six size classes were sampled over a range of spatial scales, from 10s of cm to kms, and a temporal scale of five months. The results highlighted three main features of the studied system: (1) the largest proportion of variability of sea urchins occurred at the smallest scale examined; (2) urchins from different size classes showed different patterns of abundance in relation to habitat traits; (3) variables normally invoked as potential drivers of distribution of urchins at a range of scales, such as hydrodynamics and shore height, were relatively less important than other abiotic (i.e. pool area, pool mean depth calculated over five replicate measures and sand cover) and biological (i.e. space occupancy by the reef-forming polychaete Sabellaria alveolata and mussels vs. availability of bare rock) variables to provide a considerable contribution to the variability of sea urchins. Intertidal populations of sea urchins are abundant on many rocky shores, where they are socially and economically important as food resource and ecologically key as habitat modelers. This study provides new clues on relatively unstudied populations, with relevant implications for possible management decisions, including the implementation of protection schemes able to preserve the main recruitment, settlement and development areas of P. lividus.

  17. Correlation analyses of covering and righting behaviors to fitness related traits of the sea urchin Glyptocidaris crenularis in diff erent environmental conditions

    Wei, Jing; Zhang, Lisheng; Zhao, Chong; Feng, Wenping; Sun, Ping; Chang, Yaqing

    2016-03-01

    Complex marine benthic environments shape a number of ecologically important behaviors in sea urchins, including covering and righting behaviors. The present study correlated covering and righting behaviors to a series of fitness-related traits in sea urchins. Righting response time of Glyptocidaris crenularis was significantly positively correlated with body size, but significantly negatively correlated with food consumption. Covering behavior was not significantly correlated with test diameter, test height or body weight, but covering response time was negatively correlated with body weight. A significantly negative correlation was found between righting response time and covering response time. Glyptocidaris crenularis showed a significantly positive correlation in covering response time with and without exposure to poured sand, but no significance in covering ability (number of shells used to cover). The present study provides new insight into internal mechanisms and evolutionary drives of covering and righting behaviors of sea urchins.

  18. Size-dependent distribution, abundance and diurnal rhythmicity patterns in the short-spined sea urchin Anthocidaris crassispina

    Freeman, S. M.

    2003-12-01

    Little is known about the ecology and behaviour of the sea urchin Anthocidaris crassispina, particularly in relation to changes in its surrounding environment. In Cape d'Aguilar Marine Reserve, Hong Kong Island, urchins ranged from a high abundance of ˜16 ind m -2 on steeply inclined rocky outcrops, which were exposed to strong onshore waves surges, to a complete absence on gravel and sandy substrata. Using a generalized additive model (GAM) the abundance and spatial extent of A. crassispina was predicted within the Bay. Predictions were strongly associated with the surface complexity of the habitat. On steep rocky slopes A. crassispina exhibited a size-dependent gradient where the mean test diameter increased in a down-shore direction as water depth increased. Since the mechanisms for maintaining this size-dependent distribution are unknown, a translocation experiment was conducted on two different size-classes of urchins. Following translocation, both large and small size-classes of A. crassispina were able to re-establish their original size-gradient within 3-5 days. Size-dependent distribution in A. crassispina may indicate resource partitioning, although the influence of hydrodynamic conditions on test size may also mediate this segregation. Anthocidaris crassispina was predominately nocturnal with almost 100% of the population moving between dusk and dawn. Locomotory activity patterns of urchins were strongly correlated with changes in seawater depth and changes in the direction of water-flow during tidal cycles. Anthocidaris crassispina exhibited an endogenously controlled locomotory activity pattern that was synchronized with changes in the tidal cycle, and which remained free-running for ˜13 h under constant laboratory conditions.

  19. An abundance of Epsilonproteobacteria revealed in the gut microbiome of the laboratory cultured sea urchin, Lytechinus variegatus

    Joseph Antoine Hakim

    2015-10-01

    Full Text Available In this study, we have examined the bacterial community composition in the laboratory cultured sea urchin Lytechinus variegatus gut microbiome and its culture environment using NextGen amplicon sequencing of the V4 segment of the 16S rRNA gene, and downstream bioinformatics tools. Overall, the gut and tank water was dominated by Proteobacteria, whereas the feed consisted of a co-occurrence of Proteobacteria and Firmicutes at a high abundance. The gut tissue represented Epsilonproteobacteria as dominant, with order Campylobacterales at the highest relative abundance (>95%. However, the pharynx tissue was dominated by class Alphaproteobacteria. The gut digesta and egested fecal pellets had a high abundance of class Gammaproteobacteria, from which Vibrio was found to be the primary genus, and Epsilonproteobacteria, with genus Arcobacter occurring at a moderate level. At the class level, the tank water was dominated by Gammaproteobacteria, and the feed by Alphaproteobacteria. Multi-Dimensional Scaling analysis showed that the microbial community of the gut tissue clustered together, as did the pharynx tissue to the feed. The gut digesta and egested fecal pellets showed a similar relationship to the tank water. Further analysis of Campylobacterales at a lower taxonomic level using the oligotyping method revealed 37 unique types across the ten samples, where Oligotype 1 was primarily represented in the gut tissue. BLAST analysis identified Oligotype 1 to be Arcobacter sp., Sulfuricurvum sp., and Arcobacter bivalviorum at an identity level >90%. This study showed that although distinct microbial communities were evident across multiple components of the sea urchin gut ecosystem, there is a noticeable correlation between the overall microbial communities of the gut with the sea urchin L. variegatus culture environment.

  20. An abundance of Epsilonproteobacteria revealed in the gut microbiome of the laboratory cultured sea urchin, Lytechinus variegatus.

    Hakim, Joseph A; Koo, Hyunmin; Dennis, Lacey N; Kumar, Ranjit; Ptacek, Travis; Morrow, Casey D; Lefkowitz, Elliot J; Powell, Mickie L; Bej, Asim K; Watts, Stephen A

    2015-01-01

    In this study, we have examined the bacterial community composition of the laboratory cultured sea urchin Lytechinus variegatus gut microbiome and its culture environment using NextGen amplicon sequencing of the V4 segment of the 16S rRNA gene, and downstream bioinformatics tools. Overall, the gut and tank water was dominated by Proteobacteria, whereas the feed consisted of a co-occurrence of Proteobacteria and Firmicutes at a high abundance. The gut tissue represented Epsilonproteobacteria as dominant, with order Campylobacterales at the highest relative abundance (>95%). However, the pharynx tissue was dominated by class Alphaproteobacteria. The gut digesta and egested fecal pellets had a high abundance of class Gammaproteobacteria, from which Vibrio was found to be the primary genus, and Epsilonproteobacteria, with genus Arcobacter occurring at a moderate level. At the class level, the tank water was dominated by Gammaproteobacteria, and the feed by Alphaproteobacteria. Multi-Dimensional Scaling analysis showed that the microbial community of the gut tissue clustered together, as did the pharynx tissue to the feed. The gut digesta and egested fecal pellets showed a similarity relationship to the tank water. Further analysis of Campylobacterales at a lower taxonomic level using the oligotyping method revealed 37 unique types across the 10 samples, where Oligotype 1 was primarily represented in the gut tissue. BLAST analysis identified Oligotype 1 to be Arcobacter sp., Sulfuricurvum sp., and Arcobacter bivalviorum at an identity level >90%. This study showed that although distinct microbial communities are evident across multiple components of the sea urchin gut ecosystem, there is a noticeable correlation between the overall microbial communities of the gut with the sea urchin L. variegatus culture environment. PMID:26528245

  1. Extracellular Ca2+ influx is crucial for the early embryonic development of the sea urchin Echinometra lucunter.

    de Araújo Leite, Jocelmo Cássio; Marques-Santos, Luis Fernando

    2012-03-01

    The involvement of Ca(2+) in the activation of eggs and in the first steps of the embryonic development of several species is a well-known phenomenon. An association between Ca(2+) sources with the fate of the blastopore during embryonic development has been investigated by several authors. Ca(2+) influx mediated by voltage-gated channels and Ca(2+) mobilization from intracellular stores are the major sources of Ca(2+) to egg activation and succeeding cell divisions. Studies on sea urchins embryonic development show that intracellular Ca(2+) stores are responsible for egg activation and early embryogenesis. In the present work we investigated the involvement of extracellular Ca(2+) in the first stages of the embryonic development of the sea urchin Echinometra lucunter. Divalent cation chelators EDTA and EGTA strongly blocked the early embryonic development. Adding to this, we demonstrated the involvement of voltage-gated Ca(2+) channels in E. lucunter embryogenesis since Ca(2+) channel blockers powerfully inhibited the early embryonic development. Our data also revealed that Ca(2+) influx is crucial for embryonic development during only the first 40 min postfertilization. However, intracellular Ca(2+) remains mandatory to embryonic development 40 min postfertilization, seen that both the intracellular Ca(2+) chelator BAPTA-AM and calmodulin antagonists trifluoperazine and chlorpromazine inhibited the first stages of development when added to embryos culture 50 min postfertilization. Our work highlights the crucial role of extracellular Ca(2+) influx through voltage-gated Ca(2+) channels for the early embryonic development of the sea urchin E. lucunter and characterizes an exception in the phylum Echinodermata. PMID:22532474

  2. Green sea urchin (Strongylocentrotus droebachiensis,Müller) in aquaculture: the effects of environmental factors on gonad growth.

    Siikavuopio, Sten Ivar

    2009-01-01

    Papers number 1, 2, 3, 5, 6, 7, 8, 9 and 10 of the thesis are not available in Munin due to publishers' restrictions: 1. Siikavuopio, S. I., Mortensen. A., Christiansen, J. S.: "Effects of body weight and temperature on feeding, gonad growth and oxygen consumption in green sea urchin, Strongylocentrotus droebachiensis." Aquaculture 2008; 281, 77-82 (Elsevier). Available at http://dx.doi.org/http://dx.doi.org/10.1016j.aquaculture.2008.05.033>2. Siikavuopio, S. I., Christiansen, J.S., Dale, T....

  3. POPULATION PHARMACOKINETICS OF ENROFLOXACIN AND ITS METABOLITE CIPROFLOXACIN IN THE GREEN SEA URCHIN (STRONGYLOCENTROTUS DROEBACHIENSIS) FOLLOWING INTRACOELOMIC AND IMMERSION ADMINISTRATION.

    Phillips, Brianne E; Harms, Craig A; Lewbart, Gregory A; Lahner, Lesanna L; Haulena, Martin; Rosenberg, Justin F; Papich, Mark G

    2016-03-01

    Sea urchin mass mortality events have been attributed to both infectious and noninfectious etiologies. Bacteria, including Vibrio spp. and Pseudoalteromonas spp., have been isolated during specific mortality events. Aquarium collection sea urchins are also subject to bacterial infections and could benefit from antimicrobial treatment, but pharmacokinetic studies have been lacking for this invertebrate group until recently. This study evaluated the pharmacokinetics of enrofloxacin and its active metabolite ciprofloxacin in the green sea urchin (Strongylocentrotus droebachiensis) after intracoelomic injection and medicated bath immersion administration. The utility of a population pharmacokinetic method using nonlinear mixed effects modeling (NLME) was also evaluated. Thirty sea urchins were assigned to either the injection or immersion group. Twelve study animals and three untreated controls were utilized for each administration method: enrofloxacin 10 mg/kg intracoelomic injection or a 6-hr enrofloxacin 10 mg/L immersion. Each animal was sampled four times from 0 to 120 hr. Water samples were collected during immersion treatment and posttreatment time points in both groups. Hemolymph and water sample drug concentrations were analyzed using high-performance liquid chromatography, and pharmacokinetic parameters were determined using an NLME population pharmacokinetic method. Enrofloxacin concentrations were fit to a two-compartment model with first-order input for the intracoelomic injection group. The enrofloxacin elimination half-life (t½), peak hemolymph concentration (CMAX), and area under the curve (AUC) were 38.82 hr, 90.92 μg/ml, and 1,199 hr·μg/ml, respectively. Enrofloxacin was modeled to a one-compartment model with first-order input for the immersion treatment. The enrofloxacin t½, CMAX, and AUC were 33.46 hr, 0.48 μg/ml, and 32.88 hr·μg/ml, respectively. Ciprofloxacin was detected in trace concentrations in all hemolymph samples, indicating

  4. Molecular cloning of the first metazoan beta-1,3 glucanase from eggs of the sea urchin Strongylocentrotus purpuratus.

    Bachman, E S; McClay, D R

    1996-01-01

    We report the molecular cloning of the first beta-1,3 glucanase from animal tissue. Three peptide sequences were obtained from beta-1,3 glucanase that had been purified from eggs of the sea urchin Strongylocentrotus purpuratus and the gene was cloned by PCR using oligonucleotides deduced from the peptide sequences. The full-length cDNA shows a predicted enzyme structure of 499 aa with a hydrophobic signal sequence. A 3.2-kb message is present in eggs, during early embryogenesis, and in adult ...

  5. Toxic effects of glyphosate-based herbicides on cell cycle regulation and early development of the sea urchin embryo

    Marc, Julie

    2004-01-01

    The use of early development of the sea urchin has allowed us to identify specific dysfunctions of cell cycle and early development. We show that Roundup causes a delay in the appearance of the first mitotic division; it delays the activation of complex regulator of entry into M phase, the complex CDK / cyclin B. The initial molecular target of the roundup is the activity of DNA synthesis. The transition of the monitoring mechanism G2M detects the anomaly and causes cell cycle delay. At the s...

  6. Embryonic, larval, and early juvenile development of the tropical sea urchin, Salmacis sphaeroides (Echinodermata: Echinoidea).

    Rahman, M Aminur; Yusoff, Fatimah Md; Arshad, A; Shamsudin, Mariana Nor; Amin, S M N

    2012-01-01

    Salmacis sphaeroides (Linnaeus, 1758) is one of the regular echinoids, occuring in the warm Indo-West Pacific, including Johor Straits, between Malaysia and Singapore. In order to investigate the developmental basis of morphological changes in embryos and larvae, we documented the ontogeny of S. sphaeroides in laboratory condition. Gametes were obtained from adult individuals by 0.5 M KCl injection into the coelomic cavity. Fertilization rate at limited sperm concentration (10(-5) dilution) was 96.6 ± 1.4% and the resulting embryos were reared at 24°C. First cleavage (2-cell), 4-cell, 8-cell, 16-cell, 32-cell, and multicell (Morulla) stages were achieved 01.12, 02.03, 02.28, 02.51, 03.12, and 03.32 h postfertilization. Ciliated blastulae with a mean length of 174.72 ± 4.43 μm hatched 08.45 h after sperm entry. The gastrulae formed 16.15 h postfertilization and the archenteron elongated constantly while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larva started to feed unicellular algae in 2 d, grew continuously, and finally attained metamorphic competence in 35 d after fertilization. Metamorphosis took approximately 1 h 30 min from attachment to the complete resorption of larval tissues and the development of complete juvenile structure with adult spines, extended tubefeet and well-developed pedicellaria, the whole event of which usually took place within 1 d postsettlement. This study represents the first successful investigation on embryonic, larval, and early juvenile development of S. sphaeroides. The findings would greatly be helpful towards the understanding of ontogeny and life-history strategies, which will facilitate us to develop the breeding, seed production, and culture techniques of sea urchins in captive condition. PMID:23055824

  7. Symbiosis initiation in the bacterially luminous sea urchin cardinalfish Siphamia versicolor.

    Dunlap, P V; Gould, A L; Wittenrich, M L; Nakamura, M

    2012-09-01

    To determine how each new generation of the sea urchin cardinalfish Siphamia versicolor acquires the symbiotic luminous bacterium Photobacterium mandapamensis, and when in its development the S. versicolor initiates the symbiosis, procedures were established for rearing S. versicolor larvae in an aposymbiotic state. Under the conditions provided, larvae survived and developed for 28 days after their release from the mouths of males. Notochord flexion began at 8 days post release (dpr). By 28 dpr, squamation was evident and the caudal complex was complete. The light organ remained free of bacteria but increased in size and complexity during development of the larvae. Thus, aposymbiotic larvae of the fish can survive and develop for extended periods, major components of the luminescence system develop in the absence of the bacteria and the bacteria are not acquired directly from a parent, via the egg or during mouth brooding. Presentation of the symbiotic bacteria to aposymbiotic larvae at 8-10 dpr, but not earlier, led to initiation of the symbiosis. Upon colonization of the light organ, the bacterial population increased rapidly and cells forming the light-organ chambers exhibited a differentiated appearance. Therefore, the light organ apparently first becomes receptive to colonization after 1 week post-release development, the symbiosis is initiated by bacteria acquired from the environment and bacterial colonization induces morphological changes in the nascent light organ. The abilities to culture larvae of S. versicolor for extended periods and to initiate the symbiosis in aposymbiotic larvae are key steps in establishing the experimental tractability of this highly specific vertebrate and microbe mutualism. PMID:22957874

  8. Photoreactivation of developmental abnormality in sea urchin embryos induced by UV-irradiated sperm

    The effects of UV-irradiation of sperm on the embryonic development of sea urchins (H. pulcherrimus, Anthocidaris crassispina, Pseudocentrotus depressus, and C. japonicus) were studied. Eggs inseminated with UV-irradiated sperm developed almost normally into blastulae without arrest of cleavage or hatching, even though they showed some division delay. Morphogenesis was disturbed in and after the gastrula stage, and the formation of normal pluteus larvae was inhibited depending on the UV dose (5 - 30 J/m2) given to the sperm. Morphological abnormalities observed were as follows: inhibition of gastrulation; abnormal delamination and random arrangement of primary mesenchymal cells onto the ectodermal wall; abnormal localization or an excess number of spicules; malformed skeletons. These developmental abnormalities were photoreactivated with high efficiency. Inhibition of pluteus formation to less than 5% by the UV-irradiation with 20 J/m2 completely recovered under fluorescent light illumination with 10 klux. By treating the eggs with brief illumination at various times after insemination, a stage-dependent change of the photoreactivation (PR) efficiency was found. PR treatment after the insemination up to the onset of the first DNA synthesizing phase was highly effective for the recovery, while the PR efficiency began to decrease during the S phase, becoming zero on and after the end of the phase. In eggs fertilized with UV-irradiated sperm, mitoses were abnormal and shromosomal bridges were formed at the anaphase of the first mitosis. Their frequency increased depending on the UV dose. The mitotic abnormality was also photoreactivated with visible light treatment after fertilization. The change in PR efficiency of the illumination was very similar to that of morphological abnormality. (Author)

  9. Embryonic, Larval, and Early Juvenile Development of the Tropical Sea Urchin, Salmacis sphaeroides (Echinodermata: Echinoidea

    M. Aminur Rahman

    2012-01-01

    Full Text Available Salmacis sphaeroides (Linnaeus, 1758 is one of the regular echinoids, occuring in the warm Indo-West Pacific, including Johor Straits, between Malaysia and Singapore. In order to investigate the developmental basis of morphological changes in embryos and larvae, we documented the ontogeny of S. sphaeroides in laboratory condition. Gametes were obtained from adult individuals by 0.5 M KCl injection into the coelomic cavity. Fertilization rate at limited sperm concentration (10−5 dilution was 96.6±1.4% and the resulting embryos were reared at 24°C. First cleavage (2-cell, 4-cell, 8-cell, 16-cell, 32-cell, and multicell (Morulla stages were achieved 01.12, 02.03, 02.28, 02.51, 03.12, and 03.32 h postfertilization. Ciliated blastulae with a mean length of 174.72±4.43 μm hatched 08.45 h after sperm entry. The gastrulae formed 16.15 h postfertilization and the archenteron elongated constantly while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larva started to feed unicellular algae in 2 d, grew continuously, and finally attained metamorphic competence in 35 d after fertilization. Metamorphosis took approximately 1 h 30 min from attachment to the complete resorption of larval tissues and the development of complete juvenile structure with adult spines, extended tubefeet and well-developed pedicellaria, the whole event of which usually took place within 1 d postsettlement. This study represents the first successful investigation on embryonic, larval, and early juvenile development of S. sphaeroides. The findings would greatly be helpful towards the understanding of ontogeny and life-history strategies, which will facilitate us to develop the breeding, seed production, and culture techniques of sea urchins in captive condition.

  10. Cell-surface proteoglycan in sea urchin primary mesenchyme cell migration

    Lane, M.C.

    1989-01-01

    Early in the development of the sea urchin embryo, the primary mesenchyme cells (PMC) migrate along the basal lamina of the blastocoel. Migration is inhibited in L. pictus embryos cultured in sulfate-free seawater and in S. purpuratus embryos exposed to exogenous {beta}-D-xylosides. An in vitro assay was developed to test the migratory capacity of normal PMC on normal and treated blastocoelic matrix. Sulfate deprivation and exposure to exogenous xyloside render PMC nonmotile on either matrix. Materials removed from the surface of normal PMC by treatment with 1 M urea restored migratory ability to defective cells, whereas a similar preparation isolated from the surface of epithelial cells at the same stage did not. Migration also resumed when cells were removed from the xyloside or returned to normal seawater. The urea extract was partially purified and characterized by radiolabeling, gel electrophoresis, fluorography, ion exchange chromatography, and western blotting. The PMC synthesize a large chondroitin sulfate/dermatan sulfate proteoglycan that is present in an active fraction isolated by chromatography. Chondroitinase ABC digestion of live cells blocked migration reversibly, further supporting the identification of the chondroitin sulfate/dermatan sulfate proteoglycan as the active component in the urea extract. Much of the incorporated sulfate was distributed along the filopodia in {sup 35}SO{sub 4}-labelled PMC by autoradiography. The morphology of normal and treated S. purpuratus PMC was examined by scanning electron microscopy, and differences in spreading, particularly of the extensive filopodia present on the cells, was observed. A model for the role of the chondroitin sulfate/dermatan sulfate proteoglycan in cell detachment during migration is proposed.

  11. Mesomere-derived glutamate decarboxylase-expressing blastocoelar mesenchyme cells of sea urchin larvae

    Hideki Katow

    2013-12-01

    The ontogenetic origin of blastocoelar glutamate decarboxylase (GAD-expressing cells (GADCs in larvae of the sea urchin Hemicentrotus pulcherrimus was elucidated. Whole-mount in situ hybridisation (WISH detected transcription of the gene that encodes GAD in H. pulcherrimus (Hp-gad in unfertilised eggs and all blastomeres in morulae. However, at and after the swimming blastula stage, the transcript accumulation was particularly prominent in clumps of ectodermal cells throughout the embryonic surface. During the gastrula stage, the transcripts also accumulated in the endomesoderm and certain blastocoelar cells. Consistent with the increasing number of Hp-gad transcribing cells, immunoblot analysis indicated that the relative abundance of Hp-Gad increased considerably from the early gastrula stage until the prism stage. The expression pattern of GADCs determined by immunohistochemistry was identical to the pattern of Hp-gad transcript accumulation determined using WISH. In early gastrulae, GADCs formed blastocoelar cell aggregates around the blastopore with primary mesenchyme cells. The increase in the number of blastocoelar GADCs was inversely proportional to the number of ectodermal GADCs ranging from a few percent of total GADCs in early gastrulae to 80% in late prism larvae; this depended on ingression of ectodermal GADCs into the blastocoel. Some of the blastocoelar GADCs were fluorescein-positive in the larvae that developed from the 16-cell stage chimeric embryos; these comprised fluorescein-labeled mesomeres and unlabelled macromeres and micromeres. Our finding indicates that some of the blastocoelar GADCs are derived from the mesomeres and thus they are the new group of mesenchyme cells, the tertiary mesenchyme cells.

  12. Cell-surface proteoglycan in sea urchin primary mesenchyme cell migration

    Early in the development of the sea urchin embryo, the primary mesenchyme cells (PMC) migrate along the basal lamina of the blastocoel. Migration is inhibited in L. pictus embryos cultured in sulfate-free seawater and in S. purpuratus embryos exposed to exogenous β-D-xylosides. An in vitro assay was developed to test the migratory capacity of normal PMC on normal and treated blastocoelic matrix. Sulfate deprivation and exposure to exogenous xyloside render PMC nonmotile on either matrix. Materials removed from the surface of normal PMC by treatment with 1 M urea restored migratory ability to defective cells, whereas a similar preparation isolated from the surface of epithelial cells at the same stage did not. Migration also resumed when cells were removed from the xyloside or returned to normal seawater. The urea extract was partially purified and characterized by radiolabeling, gel electrophoresis, fluorography, ion exchange chromatography, and western blotting. The PMC synthesize a large chondroitin sulfate/dermatan sulfate proteoglycan that is present in an active fraction isolated by chromatography. Chondroitinase ABC digestion of live cells blocked migration reversibly, further supporting the identification of the chondroitin sulfate/dermatan sulfate proteoglycan as the active component in the urea extract. Much of the incorporated sulfate was distributed along the filopodia in 35SO4-labelled PMC by autoradiography. The morphology of normal and treated S. purpuratus PMC was examined by scanning electron microscopy, and differences in spreading, particularly of the extensive filopodia present on the cells, was observed. A model for the role of the chondroitin sulfate/dermatan sulfate proteoglycan in cell detachment during migration is proposed

  13. Hyperlensing at NIR frequencies using a hemispherical metallic nanowire lens in a sea-urchin geometry.

    Bisht, Ankit; He, Wei; Wang, Xiaotian; Wu, Linda Y L; Chen, Xiaodong; Li, Shuzhou

    2016-05-19

    Label-free and real time far-field super-resolution imaging (hyperlensing) at the nanoscale is of significant interest where sub-λ imaging remains a constraint because of Abbe's diffraction limit. Though by utilizing anisotropic permittivities, metal-dielectric multilayers have been successful in reconstructing high-frequency components of sub-λ objects, yet they remain cumbersome and expensive to make. Most of the multilayer structures require multiple vacuum deposition cycles and are plagued by stringent requirements on the surface roughness of metallic layers. In contrast to the multilayer structure here we propose a 3D hyperbolic metamaterial model composed of metallic nanorods arranged in a sea-urchin geometry as a hyper-lensing device, which is capable of projecting and magnifying diffraction limited information into the far-field at Near-infrared (NIR) frequencies. The hyperlens generates a band of flat hyperbolic dispersions in spherical coordinates, which in turn supports the propagation of high wave-vector spatial harmonics leading to far-field super-resolution imaging. Using full-wave finite-difference time-domain (FDTD) simulations with diffraction limited trimer, quadrumer and ringed objects etched on thin perfect electric conductor (PEC) films, we show that the hyperlens model can achieve magnification factors of up to 10× in the far-field (∼4.5λ from the object's surface) under a light source with a wavelength of 1 μm, with successful resolution down to 220 nm (∼λ/5). The magnified image field distribution projected into the far-field is shown to follow the object under a reduction in the symmetry. These results are important for making progress in the realization of real-time biomolecular imaging systems, eliminating the need for near-field scanning, destructive electron microscopy and various image post-processing techniques. PMID:27149522

  14. Effects of increased pCO2 and geographic origin on purple sea urchin (Strongylocentrotus purpuratus calcite elemental composition

    J. D. Hosfelt

    2012-12-01

    Full Text Available Ocean acidification will likely have negative impacts on invertebrates producing skeletons composed of calcium carbonate. Skeletal solubility is partly controlled by the incorporation of "foreign" ions (such as Mg and Sr into the crystal lattice of these skeletal structures, a process that is sensitive to a variety of biological and environmental factors. Here we explore the effects of life stage, oceanographic region of origin, and changes in the partial pressure of carbon dioxide in seawater (pCO2 on trace elemental composition in the purple sea urchin (Strongylocentrotus purpuratus. We show that, similar to other urchin taxa, adult purple sea urchins have the ability to precipitate skeleton composed of a range of biominerals spanning low to high magnesium calcites. Mg/Ca and Sr/Ca ratios were substantially lower in adult spines compared to adult tests. On the other hand, trace elemental composition was invariant among adults collected from four oceanographically distinct regions along the US west coast (Oregon, Northern California, Central California, and Southern California. Skeletons of newly settled juvenile urchins that originated from adults from the four regions exhibited intermediate Mg/Ca and Sr/Ca between adult spine and test endmembers, indicating that skeleton precipitated during early life stages is more soluble than adult spines and less soluble than adult tests. Mean skeletal Mg/Ca or Sr/Ca of juvenile skeleton did not vary with source region when larvae were reared under present-day, global-average seawater carbonate conditions (400 ppm; pH = 8.02 ± 0.03 1 SD; Ωcalcite = 3.3 ± 0.2 1 SD. However, when reared under elevated CO2 (900 ppm; pH = 7.72 ± 0.03; Ωcalcite = 1.8 ± 0.1, skeletal Sr/Ca in juveniles exhibited increased variance across the four regions. Although larvae from the northern populations (Oregon, Northern California, Central California did not exhibit differences in Mg or Sr incorporation under elevated CO2

  15. Sea urchin development in a global change hotspot, potential for southerly migration of thermotolerant propagules

    Byrne, M.; Selvakumaraswamy, P.; Ho, M. A.; Woolsey, E.; Nguyen, H. D.

    2011-03-01

    The distribution of the sea urchin Heliocidaris erythrogramma coincides with the southeast Australia global change hot spot where marine ecosystems are warming significantly due to changes in ocean circulation. To address questions on future vulnerabilities, the thermotolerance of the planktonic life phase of H. erythrogramma was investigated in the climate and regionally relevant setting of projected near-future (2100) ocean warming. Experimental treatments ranged from 18 to 26 °C, with 26 °C representing +3-4 °C above recent ambient sea-surface temperatures. Developmental success across all stages (gastrula, 24 h; larva, 72 h; juvenile, 120 h) decreased with increasing temperature. Development was tolerant to a +1-2 °C increase above ambient, but significant deleterious effects were evident at +3-4 °C. However, larvae that developed through the early bottleneck of normal development at 26 °C metamorphosed successfully. The inverse relationship between temperature and planktonic larval duration (PLD) was seen in a 25% decrease in the PLD of H. erythrogramma at 24 and 26 oC. Ocean warming may be advantageous to a subset of larvae through early settlement and reduction of the vulnerable planktonic period. This positive effect of temperature may help buffer the negative effects of ocean warming. In parallel studies with progeny derived from northern (Coffs Harbour) and southern (Sydney) H. erythrogramma, northern embryos had significantly higher thermotolerance. This provides the possibility that H. erythrogramma populations might keep up with a warming world through poleward migration of thermotolerant propagules, facilitated by the strong southward flow of the East Australian Current. It is uncertain whether H. erythrogramma populations at the northern range of this species, with no source of immigrants, will have the capacity to persist in a warm ocean. Due to its extensive latitudinal distribution, its potential developmental thermotolerance and

  16. Habitat and scale shape the demographic fate of the keystone sea urchin Paracentrotus lividus in Mediterranean macrophyte communities.

    Patricia Prado

    Full Text Available Demographic processes exert different degrees of control as individuals grow, and in species that span several habitats and spatial scales, this can influence our ability to predict their population at a particular life-history stage given the previous life stage. In particular, when keystone species are involved, this relative coupling between demographic stages can have significant implications for the functioning of ecosystems. We examined benthic and pelagic abundances of the sea urchin Paracentrotus lividus in order to: 1 understand the main life-history bottlenecks by observing the degree of coupling between demographic stages; and 2 explore the processes driving these linkages. P. lividus is the dominant invertebrate herbivore in the Mediterranean Sea, and has been repeatedly observed to overgraze shallow beds of the seagrass Posidonia oceanica and rocky macroalgal communities. We used a hierarchical sampling design at different spatial scales (100 s, 10 s and <1 km and habitats (seagrass and rocky macroalgae to describe the spatial patterns in the abundance of different demographic stages (larvae, settlers, recruits and adults. Our results indicate that large-scale factors (potentially currents, nutrients, temperature, etc. determine larval availability and settlement in the pelagic stages of urchin life history. In rocky macroalgal habitats, benthic processes (like predation acting at large or medium scales drive adult abundances. In contrast, adult numbers in seagrass meadows are most likely influenced by factors like local migration (from adjoining rocky habitats functioning at much smaller scales. The complexity of spatial and habitat-dependent processes shaping urchin populations demands a multiplicity of approaches when addressing habitat conservation actions, yet such actions are currently mostly aimed at managing predation processes and fish numbers. We argue that a more holistic ecosystem management also needs to incorporate the

  17. Developmental abnormalities and neurotoxicological effects of CuO NPs on the black sea urchin Arbacia lixula by embryotoxicity assay.

    Maisano, Maria; Cappello, Tiziana; Catanese, Eva; Vitale, Valeria; Natalotto, Antonino; Giannetto, Alessia; Barreca, Davide; Brunelli, Elvira; Mauceri, Angela; Fasulo, Salvatore

    2015-10-01

    The embryotoxicity of CuO NPs was evaluated in the black sea urchin Arbacia lixula embryos, by using 24-well plates. Fertilized eggs were exposed to five doses of CuO NPs ranging from 0.07 to 20 ppb, until pluteus stage. CuO NPs suspensions in artificial seawater formed agglomerates of 80-200 nm size, and copper uptake was 2.5-fold up in larvae exposed to high NP concentrations in respect to control. Developmental delay and morphological alteration, including skeletal abnormalities, were observed, as well as impairment in cholinergic and serotonergic nervous systems. These findings suggest the potential of CuO NPs to interfere with the normal neurotransmission pathways, thus affecting larval morphogenesis. Overall, the embryotoxicity tests are effective for evaluation of nanoparticle effects on the health of aquatic biota. Furthermore, as the black sea urchin A. lixula demonstrated to be vulnerable to NP exposure, it may be a valid bioindicator in marine biomonitoring and ecotoxicological programmes. PMID:26026240

  18. Expression of spicule matrix protein gene SM30 in embryonic and adult mineralized tissues of sea urchin Hemicentrotus pulcherrimus

    Kitajima, T.; Tomita, M.; Killian, C. E.; Akasaka, K.; Wilt, F. H.

    1996-01-01

    We have isolated a cDNA clone for spicule matrix protein, SM30, from sea urchin Hemicentrotus pulcherrimus and have studied the expression of this gene in comparison with that of another spicule matrix protein gene, SM50. In cultured micromeres as well as in intact embryos transcripts of SM30 were first detectable around the onset of spicule formation and rapidly increased with the growth of spicules, which accompanied accumulation of glycosylated SM30 protein(s). When micromeres were cultured in the presence of Zn2+, spicule formation and SM30 expression were suppressed, while both events resumed concurrently after the removal of Zn2+ from the culture medium. Expression of SM50, in contrast, started before the appearance of spicules and was not sensitive to Zn2+. Differences were also observed in adult tissues; SM30 mRNA was detected in spines and tube feet but not in the test, while SM50 mRNA was apparent in all of these mineralized tissues at similar levels. These results strongly suggest that the SM30 gene is regulated by a different mechanism to that of the SM50 gene and that the products of these two genes are differently involved in sea urchin biomineralization. A possible role of SM30 protein in skeleton formation is discussed.

  19. Chloral hydrate alters the organization of the ciliary basal apparatus and cell organelles in sea urchin embryos

    Chakrabarti, A.; Schatten, H.; Mitchell, K. D.; Crosser, M.; Taylor, M.

    1998-01-01

    The mitotic inhibitor, chloral hydrate, induces ciliary loss in the early embryo phase of Lytechinus pictus. It causes a breakdown of cilia at the junction of the cilium and the basal body known as the basal plate. This leaves the plasma membrane temporarily unsealed. The basal apparatus accessory structures, consisting of the basal body, basal foot, basal foot cap, striated side arm, and striated rootlet, are either misaligned or disintegrated by treatment with chloral hydrate. Furthermore, microtubules which are associated with the basal apparatus are disassembled. Mitochondria accumulate at the base of cilia - underneath the plasma membrane - and show alterations in their structural organization. The accumulation of mitochondria is observed in 40% of all electron micrograph sections while 60% show the areas mostly devoid of mitochondria. The microvilli surrounding a cilium and striated rootlet remain intact in the presence of chloral hydrate. These results suggest that deciliation in early sea urchin embryos by chloral hydrate is caused by combined effects on the ciliary membrane and on microtubules in the cilia. Furthermore, it is suggested that chloral hydrate can serve as a tool to explore the cytoskeletal mechanisms that are involved in cilia motility in the developing sea urchin embryo.

  20. Systematic comparison and reconstruction of sea urchin (Echinoidea internal anatomy: a novel approach using magnetic resonance imaging

    Mueller Susanne

    2008-07-01

    Full Text Available Abstract Background Traditional comparative morphological analyses and subsequent three-dimensional reconstructions suffer from a number of drawbacks. This is particularly evident in the case of soft tissue studies that are technically demanding, time-consuming, and often prone to produce artefacts. These problems can partly be overcome by employing non-invasive, destruction-free imaging techniques, in particular micro-computed tomography or magnetic resonance imaging. Results Here, we employed high-field magnetic resonance imaging techniques to gather numerous data from members of a major marine invertebrate taxon, the sea urchins (Echinoidea. For this model study, 13 of the 14 currently recognized high-ranking subtaxa (orders of this group of animals were analyzed. Based on the acquired datasets, interactive three-dimensional models were assembled. Our analyses reveal that selected soft tissue characters can even be used for phylogenetic inferences in sea urchins, as exemplified by differences in the size and shape of the gastric caecum found in the Irregularia. Conclusion The main focus of our investigation was to explore the possibility to systematically visualize the internal anatomy of echinoids obtained from various museum collections. We show that, in contrast to classical preparative procedures, magnetic resonance imaging can give rapid, destruction-free access to morphological data from numerous specimens, thus extending the range of techniques available for comparative studies of invertebrate morphology.

  1. Novel Antimicrobial Peptides EeCentrocins 1, 2 and EeStrongylocin 2 from the Edible Sea Urchin Echinus esculentus Have 6-Br-Trp Post-Translational Modifications

    Solstad, Runar Gjerp; Li, Chun; Isaksson, Johan; Johansen, Jostein; Svenson, Johan; Stensvåg, Klara; Haug, Tor

    2016-01-01

    The global problem of microbial resistance to antibiotics has resulted in an urgent need to develop new antimicrobial agents. Natural antimicrobial peptides are considered promising candidates for drug development. Echinoderms, which rely on innate immunity factors in the defence against harmful microorganisms, are sources of novel antimicrobial peptides. This study aimed to isolate and characterise antimicrobial peptides from the Edible sea urchin Echinus esculentus. Using bioassay-guided purification and cDNA cloning, three antimicrobial peptides were characterised from the haemocytes of the sea urchin; two heterodimeric peptides and a cysteine-rich peptide. The peptides were named EeCentrocin 1 and 2 and EeStrongylocin 2, respectively, due to their apparent homology to the published centrocins and strongylocins isolated from the green sea urchin Strongylocentrotus droebachiensis. The two centrocin-like peptides EeCentrocin 1 and 2 are intramolecularly connected via a disulphide bond to form a heterodimeric structure, containing a cationic heavy chain of 30 and 32 amino acids and a light chain of 13 amino acids. Additionally, the light chain of EeCentrocin 2 seems to be N-terminally blocked by a pyroglutamic acid residue. The heavy chains of EeCentrocins 1 and 2 were synthesised and shown to be responsible for the antimicrobial activity of the natural peptides. EeStrongylocin 2 contains 6 cysteines engaged in 3 disulphide bonds. A fourth peptide (Ee4635) was also discovered but not fully characterised. Using mass spectrometric and NMR analyses, EeCentrocins 1 and 2, EeStrongylocin 2 and Ee4635 were all shown to contain post-translationally brominated Trp residues in the 6 position of the indole ring. PMID:27007817

  2. Novel Antimicrobial Peptides EeCentrocins 1, 2 and EeStrongylocin 2 from the Edible Sea Urchin Echinus esculentus Have 6-Br-Trp Post-Translational Modifications.

    Solstad, Runar Gjerp; Li, Chun; Isaksson, Johan; Johansen, Jostein; Svenson, Johan; Stensvåg, Klara; Haug, Tor

    2016-01-01

    The global problem of microbial resistance to antibiotics has resulted in an urgent need to develop new antimicrobial agents. Natural antimicrobial peptides are considered promising candidates for drug development. Echinoderms, which rely on innate immunity factors in the defence against harmful microorganisms, are sources of novel antimicrobial peptides. This study aimed to isolate and characterise antimicrobial peptides from the Edible sea urchin Echinus esculentus. Using bioassay-guided purification and cDNA cloning, three antimicrobial peptides were characterised from the haemocytes of the sea urchin; two heterodimeric peptides and a cysteine-rich peptide. The peptides were named EeCentrocin 1 and 2 and EeStrongylocin 2, respectively, due to their apparent homology to the published centrocins and strongylocins isolated from the green sea urchin Strongylocentrotus droebachiensis. The two centrocin-like peptides EeCentrocin 1 and 2 are intramolecularly connected via a disulphide bond to form a heterodimeric structure, containing a cationic heavy chain of 30 and 32 amino acids and a light chain of 13 amino acids. Additionally, the light chain of EeCentrocin 2 seems to be N-terminally blocked by a pyroglutamic acid residue. The heavy chains of EeCentrocins 1 and 2 were synthesised and shown to be responsible for the antimicrobial activity of the natural peptides. EeStrongylocin 2 contains 6 cysteines engaged in 3 disulphide bonds. A fourth peptide (Ee4635) was also discovered but not fully characterised. Using mass spectrometric and NMR analyses, EeCentrocins 1 and 2, EeStrongylocin 2 and Ee4635 were all shown to contain post-translationally brominated Trp residues in the 6 position of the indole ring. PMID:27007817

  3. Sequential expression of germ-layer specific molecules in the sea urchin embryo.

    Wessel, G M; McClay, D R

    1985-10-01

    Described are two germ-layer specific molecules that appear coincident with the formation of two germ layer cell lineages in the sea urchin embryo. Meso1 is a molecule of 380 kDa that is first detected at the time of primary mesenchyme cell delamination from the wall of the blastula. Endo1 is a molecule of 320 kDa that appears on endoderm cells at the time of archenteron formation a few hours after Meso1 appears. Both antigens are identified by monoclonal antibodies. The appearance of these antigens is described by immunofluorescence microscopy, and quantitative data on their localization has been obtained by ultrastructural immunoelectron microscopy. The synthesis of the molecules has been followed by pulse-chase immunoprecipitation. Meso1 is first expressed in trans Golgi-like saccules, is concentrated in peripheral low electron-dense vesicles, and is found throughout the plasma membrane of the mesenchymal cells and their filopodial extensions. Newly translated Meso1 can first be immunoprecipitated upon differentiation of the mesoderm cell lineage, and pulse-chase studies suggest that the determinant is the result of a post-translational modification. [35S]Methionine pulses early in development followed by a chase to the mesenchyme blastula or prism stage show that at least a portion of the molecule is translated well in advance of the mesenchyme blastula stage. Endo1, in contrast, does not appear to be translated until the onset of gastrulation, just preceding the post-translational expression of the Endo1 determinant. Endo1 is localized to the apical and basolateral cell surfaces of the midgut and hindgut. No label is detected in foregut cells, demonstrating a heterogeneity of cell populations within the endoderm cell lineage corresponding to a difference in morphology. In addition, Endo1 is shown to be the result of new transcription by the embryonic genome. Even though the function of neither molecule is known, together they show the spatial and temporal

  4. Promoter binding factors regulating cyclin B transcription in the sea urchin embryo.

    Thatcher, J D; McBride, B; Katula, K S

    1995-10-01

    Cyclin B is a key regulatory protein of the cell cycle, central to the control of the G2/M transition. In the developing sea urchin embryo, the cyclin B gene is transcriptionally regulated in concert with changing patterns of cell division. In an effort to understand the mechanism controlling cyclin B expression during development, we have conducted an analysis of the Strongylocentrotus purpuratus cyclin B gene promoter. DNase I foot-printing of the cyclin B upstream region revealed eight binding regions within 435 bp of the start of transcription; seven of these sites were within 215 bp. Found within these regions were consensus sequences for two CCAAT boxes, TATA, and E-boxes and sequences with some similarity to E2F and octamer binding motifs. Upstream sequences were functionally defined by generating cyclin B-CAT fusion genes, containing deletions and base specific mutations, and testing for relative levels of expression by gene transfer. Both CCAAT boxes were found to be essential for maximal levels of expression. A third binding site (PR7) with no recognizable consensus sequence was also found to act as a positive element. Our results suggest that protein binding to the E2F-like sequences may act to reduce expression. Protein binding was further characterized by gel mobility-shift and methylation interference. The CCAAT boxes were found to bind similar, if not identical, proteins. Sequence comparisons and methylation interference data indicate that the likely protein binding these CCAAT sequences is the characterized CCAAT-binding protein CP1. A probe containing site PR7 formed multiple gel shift complexes that, by methylation interference, appeared to be interrelated. One major complex was formed with an oligonucleotide containing the two E2F-like sequences. Protein binding to this probe was specific and required bases within the E2F-like sequences. Our results indicate that cyclin B is subject to positive and negative regulation, involving multiple factors

  5. A provisional regulatory gene network for specification of endomesoderm in the sea urchin embryo

    Davidson, Eric H.; Rast, Jonathan P.; Oliveri, Paola; Ransick, Andrew; Calestani, Cristina; Yuh, Chiou-Hwa; Minokawa, Takuya; Amore, Gabriele; Hinman, Veronica; Arenas-Mena, Cesar; Otim, Ochan; Brown, C. Titus; Livi, Carolina B.; Lee, Pei Yun; Revilla, Roger; Schilstra, Maria J.; Clarke, Peter J C.; Rust, Alistair G.; Pan, Zhengjun; Arnone, Maria I.; Rowen, Lee; Cameron, R. Andrew; McClay, David R.; Hood, Leroy; Bolouri, Hamid

    2002-01-01

    We present the current form of a provisional DNA sequence-based regulatory gene network that explains in outline how endomesodermal specification in the sea urchin embryo is controlled. The model of the network is in a continuous process of revision and growth as new genes are added and new experimental results become available; see http://www.its.caltech.edu/mirsky/endomeso.htm (End-mes Gene Network Update) for the latest version. The network contains over 40 genes at present, many newly uncovered in the course of this work, and most encoding DNA-binding transcriptional regulatory factors. The architecture of the network was approached initially by construction of a logic model that integrated the extensive experimental evidence now available on endomesoderm specification. The internal linkages between genes in the network have been determined functionally, by measurement of the effects of regulatory perturbations on the expression of all relevant genes in the network. Five kinds of perturbation have been applied: (1) use of morpholino antisense oligonucleotides targeted to many of the key regulatory genes in the network; (2) transformation of other regulatory factors into dominant repressors by construction of Engrailed repressor domain fusions; (3) ectopic expression of given regulatory factors, from genetic expression constructs and from injected mRNAs; (4) blockade of the beta-catenin/Tcf pathway by introduction of mRNA encoding the intracellular domain of cadherin; and (5) blockade of the Notch signaling pathway by introduction of mRNA encoding the extracellular domain of the Notch receptor. The network model predicts the cis-regulatory inputs that link each gene into the network. Therefore, its architecture is testable by cis-regulatory analysis. Strongylocentrotus purpuratus and Lytechinus variegatus genomic BAC recombinants that include a large number of the genes in the network have been sequenced and annotated. Tests of the cis-regulatory predictions of

  6. Monte Carlo analysis of an ODE Model of the Sea Urchin Endomesoderm Network

    Klipp Edda

    2009-08-01

    Full Text Available Abstract Background Gene Regulatory Networks (GRNs control the differentiation, specification and function of cells at the genomic level. The levels of interactions within large GRNs are of enormous depth and complexity. Details about many GRNs are emerging, but in most cases it is unknown to what extent they control a given process, i.e. the grade of completeness is uncertain. This uncertainty stems from limited experimental data, which is the main bottleneck for creating detailed dynamical models of cellular processes. Parameter estimation for each node is often infeasible for very large GRNs. We propose a method, based on random parameter estimations through Monte-Carlo simulations to measure completeness grades of GRNs. Results We developed a heuristic to assess the completeness of large GRNs, using ODE simulations under different conditions and randomly sampled parameter sets to detect parameter-invariant effects of perturbations. To test this heuristic, we constructed the first ODE model of the whole sea urchin endomesoderm GRN, one of the best studied large GRNs. We find that nearly 48% of the parameter-invariant effects correspond with experimental data, which is 65% of the expected optimal agreement obtained from a submodel for which kinetic parameters were estimated and used for simulations. Randomized versions of the model reproduce only 23.5% of the experimental data. Conclusion The method described in this paper enables an evaluation of network topologies of GRNs without requiring any parameter values. The benefit of this method is exemplified in the first mathematical analysis of the complete Endomesoderm Network Model. The predictions we provide deliver candidate nodes in the network that are likely to be erroneous or miss unknown connections, which may need additional experiments to improve the network topology. This mathematical model can serve as a scaffold for detailed and more realistic models. We propose that our method can

  7. Hyperlensing at NIR frequencies using a hemispherical metallic nanowire lens in a sea-urchin geometry

    Bisht, Ankit; He, Wei; Wang, Xiaotian; Wu, Linda Y. L.; Chen, Xiaodong; Li, Shuzhou

    2016-05-01

    Label-free and real time far-field super-resolution imaging (hyperlensing) at the nanoscale is of significant interest where sub-λ imaging remains a constraint because of Abbe's diffraction limit. Though by utilizing anisotropic permittivities, metal-dielectric multilayers have been successful in reconstructing high-frequency components of sub-λ objects, yet they remain cumbersome and expensive to make. Most of the multilayer structures require multiple vacuum deposition cycles and are plagued by stringent requirements on the surface roughness of metallic layers. In contrast to the multilayer structure here we propose a 3D hyperbolic metamaterial model composed of metallic nanorods arranged in a sea-urchin geometry as a hyper-lensing device, which is capable of projecting and magnifying diffraction limited information into the far-field at Near-infrared (NIR) frequencies. The hyperlens generates a band of flat hyperbolic dispersions in spherical coordinates, which in turn supports the propagation of high wave-vector spatial harmonics leading to far-field super-resolution imaging. Using full-wave finite-difference time-domain (FDTD) simulations with diffraction limited trimer, quadrumer and ringed objects etched on thin perfect electric conductor (PEC) films, we show that the hyperlens model can achieve magnification factors of up to 10× in the far-field (~4.5λ from the object's surface) under a light source with a wavelength of 1 μm, with successful resolution down to 220 nm (~λ/5). The magnified image field distribution projected into the far-field is shown to follow the object under a reduction in the symmetry. These results are important for making progress in the realization of real-time biomolecular imaging systems, eliminating the need for near-field scanning, destructive electron microscopy and various image post-processing techniques.Label-free and real time far-field super-resolution imaging (hyperlensing) at the nanoscale is of significant interest

  8. Characterization of the bacterial communities associated with the bald sea urchin disease of the echinoid Paracentrotus lividus

    Becker, P.; Egea, E.; Eeckhaut, I.

    2008-01-01

    The microbial communities involved in the bald sea urchin disease of the echinoid Paracentrotus lividus are investigated using culture-independent techniques. Lesions of diseased specimens from two locations in France, La Ciotat (Mediterranean Sea) and Morgat (Atlantic Ocean), are examined by Scanning Electron Microscopy (SEM) and the diversity of their microbiota is analysed by Denaturing Gradient Gel Electrophoresis (DGGE) and 16S rRNA gene clones libraries construction. Microscopic observa...

  9. High quality draft genome sequence of the slightly halophilic bacterium Halomonas zhanjiangensis type strain JSM 078169T (DSM 21076T) from a sea urchin in southern China

    Zhou, Yu; Li, Rui; Gao, Xiao-Yang; Lapidus, Alla; Han, James; Haynes, Matthew; Lobos, Elizabeth; Huntemann, Marcel; Pati, Amrita; Natalia N. Ivanova; Rohde, Manfred; Mavromatis, Konstantinos; Tindall, Brian J.; Markowitz, Victor; Woyke, Tanja

    2014-01-01

    Halomonas zhanjiangensis Chen et al. 2009 is a member of the genus Halomonas , family Halomonadaceae , class Gammaproteobacteria . Representatives of the genus Halomonas are a group of halophilic bacteria often isolated from salty environments. The type strain H. zhanjiangensis JSM 078169T was isolated from a sea urchin (Hemicentrotus pulcherrimus) collected from the South China Sea. The genome of strain JSM 078169T is the fourteenth sequenced genome in the genus Halomonas and the fifteenth i...

  10. The gut microbiome of the sea urchin, Lytechinus variegatus, from its natural habitat demonstrates selective attributes of microbial taxa and predictive metabolic profiles.

    Hakim, Joseph A; Koo, Hyunmin; Kumar, Ranjit; Lefkowitz, Elliot J; Morrow, Casey D; Powell, Mickie L; Watts, Stephen A; Bej, Asim K

    2016-09-01

    In this paper, we describe the microbial composition and their predictive metabolic profile in the sea urchin Lytechinus variegatus gut ecosystem along with samples from its habitat by using NextGen amplicon sequencing and downstream bioinformatics analyses. The microbial communities of the gut tissue revealed a near-exclusive abundance of Campylobacteraceae, whereas the pharynx tissue consisted of Tenericutes, followed by Gamma-, Alpha- and Epsilonproteobacteria at approximately equal capacities. The gut digesta and egested fecal pellets exhibited a microbial profile comprised of Gammaproteobacteria, mainly Vibrio, and Bacteroidetes. Both the seagrass and surrounding sea water revealed Alpha- and Betaproteobacteria. Bray-Curtis distances of microbial communities indicated a clustering profile with low intrasample variation. Predictive metagenomics performed on the microbial communities revealed that the gut tissue had high relative abundances of metabolisms assigned to the KEGG-Level-2 designation of energy metabolisms compared to the gut digesta, which had higher carbohydrate, amino acid and lipid metabolisms. Overall, the results of this study elaborate the spatial distribution of microbial communities in the gut ecosystem of L. variegatus, and specifically a selective attribute for Campylobacteraceae in the gut tissue. Also, the predictive functional significance of bacterial communities in uniquely compartmentalized gut ecosystems of L. variegatus has been described. PMID:27368709