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Sample records for bivalvo perumytilus purpuratus

  1. Geographical variation of shell thickness in the mussel Perumytilus purpuratus along the southeast Pacific coast.

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    Briones, Carolina; Rivadeneira, Marcelo M; Fernández, Miriam; Guiñez, Ricardo

    2014-12-01

    At broad geographical scales, the variation in bivalve shell thickness can be modulated by environmental factors that vary with latitude, such as sea surface temperature (SST), seawater pH, or calcium carbonate availability. Mussels usually form multilayered beds, and shell thickness is also expected to be affected by density and layering due to intraspecific competition. In this work, we explored the geographical variation of shell thickness in the intertidal mussel Perumytilus purpuratus between 18° and 42°S along the southeastern Pacific coast. We tested the hypothesis that there was a positive relationship between shell thickness and SST, and then we explored other variables that could have an effect on thickness, such as density, number of layers, and others environmental variables (pH and calcite concentration). The expected positive linear relationship between shell thickness and sea surface temperature was not found, but when the other population variables were included in the analysis, an unexpected inverse SST-thickness relationships appeared as significant, probably because this species could be adapted to colder and more acid seawater as are those of the tips of South America. Thickness was also negatively affected by density, which was expected for a gregarious species showing high intraspecific competition. Finally, our results highlight the importance of including density and crowding effects when macroscale patterns are explored, particularly in gregarious species, since these patterns could also be modulated by density-dependent processes, which might then override latitudinal trends of shell thickness when they are not included in the analyses. © 2014 Marine Biological Laboratory.

  2. Caracterización de algunas técnicas de inmunofluorescencia y de fluorescencia en mejillones chilenos Perumytilus purpuratus y Semimytilus algosus

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    Orlando Garrido

    2014-06-01

    Full Text Available Gametos y estadios larvales de los mejillones P. purpuratus y S. algosus fueron tratados in vitro con técnicas de fluorescencia y no fluorescencia a fin de detectar microfilamentos, DNA y gránulos corticales involucrados con estadios de la reproducción como fertilización y clivaje. En P. purouratus se detectó tubulina a nivel de los cilios y el velum; asimismo, la actina fue detectada desde el estadio de fertilización a los estadios de desarrollo tanto en P purpuratus como en S. algosus, lo que sugiere que no son descartados durante el proceso de fertilización. Los microfilamentos detectados en ambos mejillones sugieren que ellos juegan un rol importante como integrante del citoesqueleto durante el desarrollo.

  3. Cryptosporidium en moluscos bivalvos

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    Gómez Couso, Hipólito

    2005-01-01

    El objetivo del presente trabajo de investigación es contribuir al establecimiento de las bases científico-técnicas que permitan garantizar la calidad y la seguridad de los moluscos bivalvos destinados al consumo humano, determinando para ello el papel que desempeñan estos organismos en la transmisión de la cryptosporidiosis.

  4. Adiciones a la fauna de bivalvos del mar peruano

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    Carlos Paredes

    2012-10-01

    Full Text Available Se registran por primera vez para el mar peruano 10 especies de bivalvos: Ennucula panamina (Dall, 1908, Nuculana (Nuculana loshka, (Dall, 1908, Saccella laeviradius (Pilsbry & Lowe, 1932, Liralucina approximata (Dall, 1901, Carditamera radiata (G. B. Sowerby I, 1833, Carditella (Carditella naviformis (Reeve, 1843; Macoma (Psammacoma elytrum Keen, 1958, Psammotreta (Psammotreta pura (Gould, 1853, Sphenia fragilis (H. Adams & A. Adams, 1854 y Caryocorbula amethystina Olsson, 1961. Se informa sobre la distribución, el hábitat y comentarios relevantes sobre cada una de las especies.

  5. Nuevos bivalvos para el Perú en Bahía Independencia

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    Oswaldo Cornejo

    2013-06-01

    Full Text Available Se registran por primera vez para el Perú las siguientes especies de bivalvos Nucula (Nucula pisum Sowerby I, 1833, y Lyonsia delicata Marincovich, 1973, colectadas en Bahía Independencia, Pisco, Perú, en el 2002.

  6. Nuevos bivalvos para el Perú en Bahía Independencia

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    Cornejo, Oswaldo; Laboratorio de Ecología, Facultad de Ciencias Biológicas. Universidad Nacional Mayor de San Marcos; Paredes, Carlos; Laboratorio de Biología y Sistemática de Invertebrados Marinos, Facultad de Ciencias Biológicas. Universidad Nacional Mayor de San Marcos

    2013-01-01

    The following species of marine bivalves have been recorded for the first time in Peru Nucula (Nucula) pisum Sowerby I,1833 and Lyonsia delicata Marincovich,1973, colected in Independencia Bay in Pisco, Peru, at 2002. Se registran por primera vez para el Perú las siguientes especies de bivalvos Nucula (Nucula) pisum Sowerby I, 1833, y Lyonsia delicata Marincovich, 1973, colectadas en Bahía Independencia, Pisco, Perú, en el 2002.

  7. Asociación del color de la concha de reproductores de Argopecten purpuratus (Lamarck, 1819 con la supervivencia, crecimiento y desarrollo larval de sus progenies Association between shell color of breeds (Lamarck, 1819 and the survival, growth and larval development of their progenies

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    Ricardo M García

    2012-07-01

    Full Text Available Las conchas de moluscos bivalvos marinos son extremadamente diversas en sus patrones de pigmentación y riqueza de colores. Tal diversidad se debe a factores ambientales y genéticos. En bivalvos marinos adultos, individuos con coloraciones de concha poco comunes en las poblaciones silvestres suelen presentar tasas de crecimiento y supervivencia menores que aquellos con colores de concha más frecuentes. Conociendo que la variación del color de la concha en Argopecten purpuratus está bajo control genético, en este trabajo se pone a prueba la hipótesis de que los loci responsables de dicha variación pueden afectar el crecimiento, la supervivencia y la tasa de desarrollo de las larvas de esta especie. Se estimó la supervivencia y el crecimiento en progenies de cruzamientos dirigidos entre individuos de A. purpuratus con colores de concha blanco, naranja y marrón, y se verificó la existencia de diferencias en las tasas de desarrollo. El crecimiento de las larvas producidas en cruzamientos que incluyeron individuos marrones o blancos con naranja no mostraron diferencias entre sí. En cambio, las progenies producto de autofecundaciones de individuos naranja y blancos presentaron tasas de crecimiento significativamente menores que las anteriores y distintas entre sí. Las tasas de desarrollo y de supervivencia, en cambio, no mostraron diferencias entre las progenies de los distintos tipos de cruzamientos. Los resultados sugieren que los genes que controlan la variación del color en las conchas de juveniles y adultos de A. purpuratus afectarían la tasa de crecimiento de sus larvas, pero no la tasa de desarrollo ni su supervivencia.Marine bivalve mollusks are extremely diverse in shell color and pigmentation patterns. Such diversity is affected by environmental and genetic factors. Some evidences in adult marine bivalves shows that individuals with low-frequency shell colors have lower growth rates and/or higher mortalities than those with the

  8. Lectins identify distinct populations of coelomocytes in Strongylocentrotus purpuratus.

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    Liao, Wen-Yun; Fugmann, Sebastian D

    2017-01-01

    Coelomocytes represent the immune cells of echinoderms, but detailed knowledge about their roles during immune responses is very limited. One major challenge for studying coelomocyte biology is the lack of reagents to identify and purify distinct populations defined by objective molecular markers rather than by morphology-based classifications that are subjective at times. Glycosylation patterns are known to differ significantly between cell types in vertebrates, and furthermore they can vary depending on the developmental stage and activation states within a given lineage. Thus fluorescently labeled lectins that recognize distinct glycan structures on cell surface proteins are routinely used to identify discrete cell populations in the vertebrate immune system. Here we now employed a panel of fifteen fluorescently-labeled lectins to determine differences in the glycosylation features on the surface of Strongylocentrotus purpuratus coelomocytes by fluorescence microscopy and flow cytometry. Eight of the lectins (succinylated wheat germ agglutinin, Len culinaris lectin, Pisum sativum agglutinin, Saphora japonica agglutinin, Solanum tuberosum lectin, Lycopersicon esculentum lectin, Datura stramonium lectin, Vicia villosa lectin) showed distinct binding patterns to fixed and live cells of three major coelomocyte classes: phagocytic cells, red spherule cells, and vibratile cells. Importantly, almost all lectins bound only to a subgroup of cells within each cell type. Lastly, we established fluorescently-labeled lectin-based fluorescence activated cell sorting as a strategy to purify distinct S. purpuratus coelomocyte (sub-)populations based on molecular markers. We anticipate that this will become a routine approach in future studies focused on dissecting the roles of different coelomocytes in echinoderm immunity.

  9. Lectins identify distinct populations of coelomocytes in Strongylocentrotus purpuratus.

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    Wen-Yun Liao

    Full Text Available Coelomocytes represent the immune cells of echinoderms, but detailed knowledge about their roles during immune responses is very limited. One major challenge for studying coelomocyte biology is the lack of reagents to identify and purify distinct populations defined by objective molecular markers rather than by morphology-based classifications that are subjective at times. Glycosylation patterns are known to differ significantly between cell types in vertebrates, and furthermore they can vary depending on the developmental stage and activation states within a given lineage. Thus fluorescently labeled lectins that recognize distinct glycan structures on cell surface proteins are routinely used to identify discrete cell populations in the vertebrate immune system. Here we now employed a panel of fifteen fluorescently-labeled lectins to determine differences in the glycosylation features on the surface of Strongylocentrotus purpuratus coelomocytes by fluorescence microscopy and flow cytometry. Eight of the lectins (succinylated wheat germ agglutinin, Len culinaris lectin, Pisum sativum agglutinin, Saphora japonica agglutinin, Solanum tuberosum lectin, Lycopersicon esculentum lectin, Datura stramonium lectin, Vicia villosa lectin showed distinct binding patterns to fixed and live cells of three major coelomocyte classes: phagocytic cells, red spherule cells, and vibratile cells. Importantly, almost all lectins bound only to a subgroup of cells within each cell type. Lastly, we established fluorescently-labeled lectin-based fluorescence activated cell sorting as a strategy to purify distinct S. purpuratus coelomocyte (sub-populations based on molecular markers. We anticipate that this will become a routine approach in future studies focused on dissecting the roles of different coelomocytes in echinoderm immunity.

  10. Non-directional photoreceptors in the pluteus of Strongylocentrotus purpuratus

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    Alberto Valero-Gracia

    2016-11-01

    Full Text Available In comparison to complex visual systems, non-directional photoreception – the most primitive form of biological photodetection – has been poorly investigated, although it is essential to many biological processes such as circadian and seasonal rhythms. Here we describe the spatiotemporal expression pattern of the major molecular actors mediating light reception – opsins – localized in the Strongylocentrotus purpuratus larva. In contrast to other zooplanktonic larvae, the echinopluteus lacks photoreceptor cells with observable shading pigments involved in directional visual tasks. Nonetheless, the echinopluteus expresses two distinct classes of opsins: a Go-opsin and a rhabdomeric opsin. The Go-opsin, Sp-opsin3.2, is detectable at early (3 days post fertilization and four armed pluteus stages (4 days post fertilization in two cells that flank the apical organ. To rule out the presence of shading pigments involved in directional photoreception, we used electron microscopy to explore the expression domain of Go-opsin Sp-opsin3.2 positive cells. The rhabdomeric opsin Sp-Opsin4 expression is detectable in clusters of cells located around the primary podia at the five-fold ectoderm pentagonal disc stage (day 18-21 and thereafter, thus indicating that Sp-Opsin4 may not be involved in the photoreception mechanism of the larva, but only of the juvenile. We discuss the putative function of the relevant cells in their neural context, and propose a model for understanding simple photodetection in marine larvae.

  11. Dinámica de la paleodiversidad de los Bivalvos del Triásico y Jurásico Inferior.

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    Ros Franch, Sonia

    2009-01-01

    Los bivalvos son un grupo de invertebrados muy utilizado para el estudio de dinámicas evolutivas, dado que su concha los hace buenos candidatos para la fosilización y son abundantes en el registro fósil. El objetivo de esta tesis es el estudio de la paleodiversidad genérica de los bivalvos marinos en el intervalo Induense (Triásico Inferior) - Sinemuriense (Jurásico Inferior) [In-Sin], que comienza con la recuperación de la extinción del límite Pérmico - Triásico (P/T) y termina con la recupe...

  12. Dinámica de la paleodiversidad de los Bivalvos del Triásico y Jurásico Inferior.

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    Ros Franch, Sonia

    2009-01-01

    RESUMEN Los bivalvos son un grupo de invertebrados muy utilizado para el estudio de dinámicas evolutivas, dado que su concha los hace buenos candidatos para la fosilización y son abundantes en el registro fósil. El objetivo de esta tesis es el estudio de la paleodiversidad genérica de los bivalvos marinos en el intervalo Induense (Triásico Inferior) Sinemuriense (Jurásico Inferior) [In-Sin], que comienza con la recuperación de la extinción del límite Pérmico Triásico (P/T) y termina con la...

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

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    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

  14. Composición y estructura de la macrofauna asociada con agregaciones de dos especies de bivalvos en Isla de Cubagua, Venezuela

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    Iván Hernández-Ávila

    2013-06-01

    Full Text Available Las agregaciones de bivalvos constituyen un microhábitat para una gran variedad de organismos en el ambiente intermareal, submareal y en aguas profundas. Agregaciones de la ostra perla (Pinctada imbricata y pepitona (Arca zebra a diferentes densidades poblacionales se evaluaron para determinar la composición y estructura comunitaria de la macrofauna asociada en tres taxa (Crustacea Decapoda, Mollusca y Echinodermata. La hipótesis nula de no diferencias en descriptores univariados y multivariados fue probada comparando la fauna asociada entre las agregaciones de las dos especies a tres niveles de densidad. En estas agregaciones se identificaron 102 especies de 55 familias. Mithraculus forceps (Majidae, Crucibulum auricula (Calyptraeidae y Ophiotrix angulata (Ophiothrichidae fueron las especies más comunes encontradas en estas asociaciones. Las densidades medias y altas de las agregaciones de bivalvos presentaron mayor número de especies, abundancia, diversidad de Shannon, equidad, diversidad taxonómica y distinción taxonómica de la fauna asociada que las agregaciones de baja densidad poblacional. Análisis multivariados detectaron diferentes estructuras de los ensambles de la fauna asociada en agregaciones de bivalvos con densidad baja en comparación con los de densidad media y alta. Adicionalmente no se detectaron diferencias en la fauna asociada entre las especies. La densidad de las agregaciones de bivalvos, asociada a la complejidad topográfica, es un factor importante para la composición de la fauna asociada.

  15. New biomarkers of post-settlement growth in the sea urchin Strongylocentrotus purpuratus.

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    Fadl, Alyaa Elsaid Abdelaziz; Mahfouz, Magdy Elsayed; El-Gamal, Mona Mabrouk Taha; Heyland, Andreas

    2017-10-01

    Some sea urchins, including the purple sea urchin Strongylocentrotus purpuratus, have been successfully used in aquaculture, but their slow growth and late reproduction are challenging to overcome when developing efficient aquaculture production techniques. S. purpuratus develops via an indirect life history that is characterized by a drastic settlement process at the end of a larval period that lasts for several weeks. During this transition, the bilateral larva is transformed into a pentaradial juvenile, which will start feeding and growing in the benthic habitat. Due to predation and other ecological factors, settlement is typically associated with high mortality rates in juvenile populations. Additionally, juveniles require several days to develop a functional mouth and digestive system. During this perimetamorphic period, juveniles use up larval resources until they are capable to digest adult food. Mechanisms underlying the onset of juvenile feeding and metabolism have implications for the recruitment of natural populations as well as aquaculture and are relatively poorly understood in S. purpuratus . The insulin/insulin-like growth factor signalling (IIS)/Target of Rapamycin (TOR) pathway (IIS/TOR) is well conserved among animal phyla and regulates physiological and developmental functions, such as growth, reproduction, aging and nutritional status. We analyzed the expression of FoxO, TOR, and ILPs in post-settlement juveniles in conjunction with their early growth trajectories. We also tested how pre-settlement starvation affected post-settlement expression of IIS. We found that FoxO provides a useful molecular marker in early juveniles as its expression is strongly correlated with juvenile growth. We also found that pre-settlement starvation affects juvenile growth trajectories as well as IIS. Our findings provide preliminary insights into the mechanisms underlying post-settlement growth and metabolism in S. purpuratus . They also have important

  16. Histamine is a modulator of metamorphic competence in Strongylocentrotus purpuratus (Echinodermata: Echinoidea

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    Sutherby Josh

    2012-04-01

    Full Text Available Abstract Background A metamorphic life-history is present in the majority of animal phyla. This developmental mode is particularly prominent among marine invertebrates with a bentho-planktonic life cycle, where a pelagic larval form transforms into a benthic adult. Metamorphic competence (the stage at which a larva is capable to undergo the metamorphic transformation and settlement is an important adaptation both ecologically and physiologically. The competence period maintains the larval state until suitable settlement sites are encountered, at which point the larvae settle in response to settlement cues. The mechanistic basis for metamorphosis (the morphogenetic transition from a larva to a juvenile including settlement, i.e. the molecular and cellular processes underlying metamorphosis in marine invertebrate species, is poorly understood. Histamine (HA, a neurotransmitter used for various physiological and developmental functions among animals, has a critical role in sea urchin fertilization and in the induction of metamorphosis. Here we test the premise that HA functions as a developmental modulator of metamorphic competence in the sea urchin Strongylocentrotus purpuratus. Results Our results provide strong evidence that HA leads to the acquisition of metamorphic competence in S. purpuratus larvae. Pharmacological analysis of several HA receptor antagonists and an inhibitor of HA synthesis indicates a function of HA in metamorphic competence as well as programmed cell death (PCD during arm retraction. Furthermore we identified an extensive network of histaminergic neurons in pre-metamorphic and metamorphically competent larvae. Analysis of this network throughout larval development indicates that the maturation of specific neuronal clusters correlates with the acquisition of metamorphic competence. Moreover, histamine receptor antagonist treatment leads to the induction of caspase mediated apoptosis in competent larvae. Conclusions We

  17. The neuropeptide transcriptome of a model echinoderm, the sea urchin Strongylocentrotus purpuratus.

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    Rowe, Matthew L; Elphick, Maurice R

    2012-12-01

    Neuronal secretion of peptide signaling molecules (neuropeptides) is an evolutionarily ancient feature of nervous systems. Here we report the identification of 20 cDNAs encoding putative neuropeptide precursors in the sea urchin Strongylocentrotus purpuratus (Phylum Echinodermata), providing new insights on the evolution and diversity of neuropeptides. Identification of a gonadotropin-releasing hormone-like peptide precursor (SpGnRHP) is consistent with the widespread phylogenetic distribution of GnRH-type neuropeptides in the bilateria. A protein (SpTRHLP) comprising multiple copies of peptides that share structural similarity with thyrotropin-releasing hormone (TRH) is the first TRH-like precursor to be identified in an invertebrate. SpCTLP is the first calcitonin-like peptide with two N-terminally located cysteine residues to be found in a non-chordate species. Discovery of two proteins (SpPPLNP1, SpPPLNP2) comprising homologs of molluscan pedal peptides and arthropod orcokinins indicates the existence of a bilaterian family of pedal peptide/orcokinin-type neuropeptides. Other proteins identified contain peptides that do not share apparent sequence similarity with known neuropeptides. These include Spnp5, which comprises multiple copies of C-terminally amidated peptides that have an N-terminal Ala-Asn motif (AN peptides), and Spnp9, Spnp10 and Spnp12, which contain putative neuropeptides with a C-terminal Phe-amide, Ser-amide or Pro-amide, respectively. Several proteins (Spnp11, 14, 15, 16, 17, 18, 19 and 20) contain putative neuropeptides with multiple cysteine residues (2, 6 or 8), which may mediate formation of intramolecular or intermolecular disulphide bridges. Looking ahead, the identification of these neuropeptide precursors in S. purpuratus has provided a strong basis for a comprehensive analysis of neuropeptide function in this model echinoderm species. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Serotonin and its metabolism in basal deuterostomes: insights from Strongylocentrotus purpuratus and Xenoturbella bocki.

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    Squires, Leah N; Rubakhin, Stanislav S; Wadhams, Andinet Amare; Talbot, Kristen N; Nakano, Hiroaki; Moroz, Leonid L; Sweedler, Jonathan V

    2010-08-01

    Serotonin (5-HT), an important molecule in metazoans, is involved in a range of biological processes including neurotransmission and neuromodulation. Both its creation and release are tightly regulated, as is its removal. Multiple neurochemical pathways are responsible for the catabolism of 5-HT and are phyla specific; therefore, by elucidating these catabolic pathways we glean greater understanding of the relationships and origins of various transmitter systems. Here, 5-HT catabolic pathways were studied in Strongylocentrotus purpuratus and Xenoturbella bocki, two organisms occupying distinct positions in deuterostomes. The 5-HT-related compounds detected in these organisms were compared with those reported in other phyla. In S. purpuratus, 5-HT-related metabolites include N-acetyl serotonin, gamma-glutamyl-serotonin and 5-hydroxyindole acetic acid; the quantity and type were found to vary based on the specific tissues analyzed. In addition to these compounds, varying levels of tryptamine were also seen. Upon addition of a 5-HT precursor and a monoamine oxidase inhibitor, 5-HT itself was detected. In similar experiments using X. bocki tissues, the 5-HT-related compounds found included 5-HT sulfate, gamma-glutamyl-serotonin and 5-hydroxyindole acetic acid, as well as 5-HT and tryptamine. The sea urchin metabolizes 5-HT in a manner similar to both gastropod mollusks, as evidenced by the detection of gamma-glutamyl-serotonin, and vertebrates, as indicated by the presence of 5-hydroxyindole acetic acid and N-acetyl serotonin. In contrast, 5-HT metabolism in X. bocki appears more similar to common protostome 5-HT catabolic pathways.

  19. Morphological alterations in cryopreserved spermatozoa of scallop Argopecten purpuratus Alteraciones morfológicas en espermatozoides criopreservados de concha de abanico Argopecten purpuratus

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    Carlos Espinoza

    2010-01-01

    Full Text Available The present work identifies and quantifies the morphological alterations of scallop Argopecten purpuratus spermatozoa caused by long-term cryopreservation. Percentages of motility, fertilization and injured spermatozoa were quantified by optic microscopy and scanned electron microscopy. These parameters were evaluated in sperm without treatment (CTR, spermatozoa incubated in cryoprotective solution but not freezed (ICS and freezed-thawed spermatozoa (FTS. Spermatozoa of ICS treatment remained motile longer than those of CTR, whereas those of FTS treatment were lowest. Morphology of the spermatozoa was affected in several ways by the freeze-thawing treatment; some had their head deformed or swollen, others had their cell membrane folded or broken; acrosome reaction; anomalous positions or absence of mitochondria as well as broken, stiff or loss of lineal structure of tail. CTR and ICS treatments had higher percentages of undamaged sperm (87.7% and 79.0% respectively, while FTS samples had 14.2% of undamaged sperm. The tail was the spermatic structure most commonly injured in FTS (77.0%, the percentage of sperm with head injury was 55.1% and with acrosome reaction was 28.7%, whereas middle piece was affected in 23.9% of sperm. Percentages of fertilization were 68.3%, 67.9% and 58.2% for CTR, ICS and FTS respectively, which were not significantly different. There was a higher correlation between injuries and motility than between injuries and fertilization success. Correlation between motility and fertilization was low (0.605 and 0.668 with motility at 5 and 30 min, respectively.El presente trabajo identifica y cuantifica las alteraciones morfológicas en espermatozoides de concha de abanico A. purpuratus causadas por la criopreservación en nitrógeno líquido. Porcentajes de motilidad, fecundación de ovocitos frescos y espermatozoides lesionados (en cabeza, acrosoma, pieza media y flagelo fueron determinados bajo microscopía óptica y electr

  20. Ocean acidification research in the 'post-genomic' era: Roadmaps from the purple sea urchin Strongylocentrotus purpuratus.

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    Evans, Tyler G; Padilla-Gamiño, Jacqueline L; Kelly, Morgan W; Pespeni, Melissa H; Chan, Francis; Menge, Bruce A; Gaylord, Brian; Hill, Tessa M; Russell, Ann D; Palumbi, Stephen R; Sanford, Eric; Hofmann, Gretchen E

    2015-07-01

    Advances in nucleic acid sequencing technology are removing obstacles that historically prevented use of genomics within ocean change biology. As one of the first marine calcifiers to have its genome sequenced, purple sea urchins (Strongylocentrotus purpuratus) have been the subject of early research exploring genomic responses to ocean acidification, work that points to future experiments and illustrates the value of expanding genomic resources to other marine organisms in this new 'post-genomic' era. This review presents case studies of S. purpuratus demonstrating the ability of genomic experiments to address major knowledge gaps within ocean acidification. Ocean acidification research has focused largely on species vulnerability, and studies exploring mechanistic bases of tolerance toward low pH seawater are comparatively few. Transcriptomic responses to high pCO₂ seawater in a population of urchins already encountering low pH conditions have cast light on traits required for success in future oceans. Secondly, there is relatively little information on whether marine organisms possess the capacity to adapt to oceans progressively decreasing in pH. Genomics offers powerful methods to investigate evolutionary responses to ocean acidification and recent work in S. purpuratus has identified genes under selection in acidified seawater. Finally, relatively few ocean acidification experiments investigate how shifts in seawater pH combine with other environmental factors to influence organism performance. In S. purpuratus, transcriptomics has provided insight into physiological responses of urchins exposed simultaneously to warmer and more acidic seawater. Collectively, these data support that similar breakthroughs will occur as genomic resources are developed for other marine species. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Characterization and expression analysis of Galnts in developing Strongylocentrotus purpuratus embryos.

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    Amber L Famiglietti

    Full Text Available Mucin-type O-glycosylation is a ubiquitous posttranslational modification in which N-Acetylgalactosamine (GalNAc is added to the hydroxyl group of select serine or threonine residues of a protein by the family of UDP-GalNAc:Polypeptide N-Acetylgalactosaminyltransferases (GalNAc-Ts; EC 2.4.1.41. Previous studies demonstrate that O-glycosylation plays essential roles in protein function, cell-cell interactions, cell polarity and differentiation in developing mouse and Drosophila embryos. Although this type of protein modification is highly conserved among higher eukaryotes, little is known about this family of enzymes in echinoderms, basal deuterostome relatives of the chordates. To investigate the potential role of GalNAc-Ts in echinoderms, we have begun the characterization of this enzyme family in the purple sea urchin, S. purpuratus. We have fully or partially cloned a total of 13 genes (SpGalnts encoding putative sea urchin SpGalNAc-Ts, and have confirmed enzymatic activity of five recombinant proteins. Amino acid alignments revealed high sequence similarity among sea urchin and mammalian glycosyltransferases, suggesting the presence of putative orthologues. Structural models underscored these similarities and helped reconcile some of the substrate preferences observed. Temporal and spatial expression of SpGalnt transcripts, was studied by whole-mount in situ hybridization. We found that many of these genes are transcribed early in developing embryos, often with restricted expression to the endomesodermal region. Multicolor fluorescent in situ hybridization (FISH demonstrated that transcripts encoding SpGalnt7-2 co-localized with both Endo16 (a gene expressed in the endoderm, and Gcm (a gene expressed in secondary mesenchyme cells at the early blastula stage, 20 hours post fertilization (hpf. At late blastula stage (28 hpf, SpGalnt7-2 message co-expresses with Gcm, suggesting that it may play a role in secondary mesenchyme development. We

  2. Estado actual de la taxonomía de bivalvos dulceacuícolas chilenos: progresos y conflictos

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    ESPERANZA PARADA

    2002-12-01

    Full Text Available Se presenta una revisión actualizada de la taxonomía de los bivalvos dulceacuícolas chilenos. Los bivalvos descritos a la fecha, están adscritos a dos familias: Hyriidae representada sólo por el género Diplodon con dos especies (D. chilensis y D. solidulus y Sphaeriidae representada por tres géneros: Pisidium con siete especies (P. chilense, P. magellanicum, P. lebruni, P. observationis, P. meierbrooki, P. huillichum y P. llanquihuense, Sphaerium con dos especies (S. lauricochae y S. forbesi y Musculium con dos especies (M. argentinum y M. patagonicum. Entidades subgenéricas y subespecíficas son reconocidas sólo para Hyriidae. Se incluye la sinonimia, localidad tipo y distribución geográfica donde las especies han sido registradas. Los caracteres diagnósticos más confiables para la identificación de las especies de Hyriidae son la morfología de la charnela en adultos y en larvas, la presencia o ausencia de los dientes larvales, y la posición y forma de éstos. En los Sphaeriidae, los caracteres taxonómicos más confiables a nivel de género son la forma y el número de sifones, y el tamaño de ambas hemibranquias; a nivel específico, son la morfometría y morfología de las valvas, la que incluye, posición del umbo, características de la charnela, forma y tamaño de los dientes cardinales, esculpido de las valvas y densidad de poros en la superficie interna de ellas. Se discuten los resultados en relación a los progresos y conflictos respecto del ordenamiento taxonómico y sistemático en ambas familias, las dificultades para la recopilación de la información, la necesidad de redescribir algunas especies a la luz de nuevas técnicas citogenéticas y moleculares y ampliar la base de datos con nuevos registros en áreas geográficas no estudiadas aún. Se propone a Pisidium chilense, P. huillichum, P. llanquihuense y P. lebruni como especies endémicas de Chile y se bosquejan regiones zoogeográficas considerando la

  3. Cell surface of sea urchin micromeres and primary mesenchyme. [Arbacia punctulata; Strongylocentrotus drobachiensis; Strongylocentrotus purpuratus

    Energy Technology Data Exchange (ETDEWEB)

    DeSimone, D.W.

    1985-01-01

    The cell surface and extracellular matrix (ECM) of the sea urchin embryo were studied during the early morphogenetic events involved in the differentiation of the micromere cell lineage. Sixteen-cell and early cleavage stage blastomeres were isolated and the protein composition of their cell surfaces examined by /sup 125/I-labelling followed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Micromere-specific cell surface proteins are reported for Arbacia punctulata, Strongylocentrotus droebachiensis, and Strongylocentrotus purpuratus. Cell surface glycoproteins were characterized on the basis of lectin binding specificity with a novel lectin affinity transfer technique. Using this procedure, cell-type specific surface proteins, which are also lectin-binding specific, can be detected. In addition, fluorescein conjugated lectins were microinjected into the blastocoels of living S. drobachiensis and Lytechinus pictus embryos and the patterns of lectin bindings observed by fluorescence microscopy. The evidence presented in this thesis suggests that the differentiation of the primary mesenchyme cells is correlated with changes in the molecular composition of the cell-surface and the ECM.

  4. Effect of temperature on physiological responses of Peruvian scallop Argopecten purpuratus

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    Jhon Dionicio Acedo

    2015-12-01

    Full Text Available The effect of temperature on the clearance rate (CR, ingestion rate (IR and specific oxygen consumption (SOC in individuals of Argopecten purpuratus at different size groups were determined. The CR and IR tests were performed at a concentration of approximately 1x106 cel.mlL-1 of Chaetoceros calcitrans, two temperatures 17 and 22 °C were evaluated and different groups of average size were formed of 7.6 ± 0.265, and 0.058 ± 4.9 3.7 ± 0.173 cm. In SOC test the average size groups were 8.1 ± 0.351, 0.058 ± 5.6 and 4.3 ± 0.100 cm. The results show a significant effect of temperature in CR (Lh-1 and IR (cel.h-1 x 105 on the larger individuals (7.6 ± 0.265 cm, it was observed at 22 °C an average increase, about 17 °C, up to 250% to CR and 48% to IR. In addition, a direct relationship of body size with CR and IR in both temperatures was observed. The effect of temperature at 22 ° C on SOC in all groups was evaluated, with an increase of 239.8, 165.3 and 183.4% for size individuals of 8.1 ± 0.351, 0.058 ± 5.6 and 4.3 ± 0.100 respectively. Furthermore, in both evaluated temperatures, the results show an indirect relationship of body size with the SOC.

  5. Feeding behaviour and growth of the Peruvian scallop (Argopecten purpuratus) under daily cyclic hypoxia conditions

    Science.gov (United States)

    Aguirre-Velarde, Arturo; Jean, Fred; Thouzeau, Gérard; Flye-Sainte-Marie, Jonathan

    2018-01-01

    As a secondary consequence of the high productivity of the upwelling system, organisms inhabiting Peruvian coastal bays are frequently exposed to hypoxic conditions. The aim of the present paper was to investigate the effects of daily-cyclic-severe hypoxia on energetics of a species presenting little escape ability when facing hypoxia. For this purpose, juvenile Peruvian scallops (Argopecten purpuratus) were exposed to four experimental conditions: fed and starved, combined or not to nightly severe hypoxia (5% oxygen saturation) for ≈ 12 h over a 21-day experiment. In both fed conditions, clearance rate was measured by the mean of an open-flow system. Our results indicate that the Peruvian scallop is able to maintain an active filtration even at low oxygen saturation, at least during expositions up to 12 h. During the first phase of exposure to hypoxia, clearance rate decreased abruptly when oxygen saturation dropped below 10%, but rapidly recovered to values close to those found under normoxia. As a consequence of this ability to feed during hypoxia, no difference in soft tissue dry weight (digestive gland not included) was observed at the end of the experimental period between oxic conditions among fed scallops. However, shell growth was negatively affected by hypoxic condition. Starved individuals exhibited similar weight loss between hypoxic and normoxic conditions indicating no or little effect of oxic condition on maintenance costs. Considering the observed responses for feeding, growth and maintenance, we can hypothesize that this species presents metabolic/bioenergetic efficient adaptations to deal with hypoxic conditions that are recurrent in Peruvian coastal bays. We hypothesize that the small observed effects might be modelled in the context of the Dynamic Energy Budget theory as a restriction of reserve mobilization under hypoxic conditions.

  6. Biomineralization changes with food supply confer juvenile scallops (Argopecten purpuratus) resistance to ocean acidification

    KAUST Repository

    Ramajo, Laura

    2015-12-08

    Future ocean acidification (OA) will affect physiological traits of marine species, with calcifying species being particularly vulnerable. As OA entails high energy demands, particularly during the rapid juvenile growth phase, food supply may play a key role in the response of marine organisms to OA. We experimentally evaluated the role of food supply in modulating physiological responses and biomineralization processes in juveniles of the Chilean scallop, Argopecten purpuratus, that were exposed to control (pH ~ 8.0) and low pH (pH ~ 7.6) conditions using three food supply treatments (high, intermediate, and low). We found that pH and food levels had additive effects on the physiological response of the juvenile scallops. Metabolic rates, shell growth, net calcification, and ingestion rates increased significantly at low pH conditions, independent of food. These physiological responses increased significantly in organisms exposed to intermediate and high levels of food supply. Hence, food supply seems to play a major role modulating organismal response by providing the energetic means to bolster the physiological response of OA stress. On the contrary, the relative expression of chitin synthase, a functional molecule for biomineralization, increased significantly in scallops exposed to low food supply and low pH, which resulted in a thicker periostracum enriched with chitin polysaccharides. Under reduced food and low pH conditions, the adaptive organismal response was to trade-off growth for the expression of biomineralization molecules and altering of the organic composition of shell periostracum, suggesting that the future performance of these calcifiers will depend on the trajectories of both OA and food supply. Thus, incorporating a suite of traits and multiple stressors in future studies of the adaptive organismal response may provide key insights on OA impacts on marine calcifiers.

  7. Estructura comunitaria de bivalvos y gasterópodos en raíces del mangle rojo Rhizophora mangle (Rhizophoraceae en isla Larga, bahía de Mochima, Venezuela

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    Vanessa Acosta Balbas

    2014-08-01

    Full Text Available Las raíces del mangle rojo forman un complejo ecosistema donde se reproducen, refugian y establecen de manera permanente una gran diversidad de organismos. En este estudio, se evaluó la diversidad de bivalvos y gasterópodos que habitan las raíces del mangle rojo Rhizophora mangle, en isla Larga, Bahía de Mochima, estado Sucre Venezuela. Se realizaron recolectas bimensuales desde enero 2007 hasta mayo 2008, en cuatro zonas de estudio denominadas: zona sur, norte, este y oeste. En cada zona se muestrearon cinco raíces de mangle, de donde se obtuvieron los especímenes. Se analizaron un total 180 raíces y se contabilizaron 35 especies de bivalvos y 25 de gasterópodos. Los bivalvos más abundantes fueron: Isognomon alatus, Isognomon bicolor, Ostrea equestris, Crassostrea rhizophorae y Brachidontes exustus, mientras que los gasterópodos más frecuentes: Littorina angulifera, Cymatium pileare y Diodora cayenensis. Los meses donde se observaron las mayores abundancias de especies y número de individuos fueron enero y julio 2007 y marzo 2008. El ecosistema de manglar en isla Larga, presentó un número de individuos y especies superior al reportado en otros trabajos realizados en Venezuela y otras regiones del Caribe.

  8. Estudio de la variabilidad genética en poblaciones de Argopecten purpuratus de Chile y Perú

    OpenAIRE

    Ysla Ch., Luis; Facultad de Pesquería, Universidad Nacional Agraria La Molina (Perú).

    2009-01-01

    La concha de abanico (Argopecten purpuratus) se distribuye en la costa del Pacifico Sur desde Perú (Bahía de Sechura) hasta Chile (Bahía de Tongoy). El conocimiento de la estructura genética poblacional es de gran importancia para el manejo y conservación de este recurso compartido por ambos países. Para esto se estudiaron trespoblaciones de concha de abanico de cada país con el fin de compararlas, utilizando para ello electroforesis de aloenzimas. Las enzimas que tuvieron un mejor revelado f...

  9. Substratum cavities affect growth-plasticity, allometry, movement and feeding rates in the sea urchin Strongylocentrotus purpuratus.

    Science.gov (United States)

    Hernández, J C; Russell, M P

    2010-02-01

    We assessed the influence of rock cavities, or pits, on the growth dynamics and behavior of the purple sea urchin, Strongylocentrotus purpuratus. In a paired-designed, laboratory experiment, sea urchins were assigned to sandstone blocks that were either 'Flat' or had a 'Pit' drilled into the center. At the start, both groups were approximately the same shape and size. In just 2 months, the shapes of the tests were significantly different between the two treatments, with the Pit urchins having an increased height:diameter profile. This result demonstrates the plastic nature of the sea urchin test and that, despite its apparent rigidity, it is capable of deforming during growth. In addition, the presence of pits modified behavior and food consumption as well as allometric growth of the test and Aristotle's lantern. Sea urchins on Pit sandstone blocks tended to stay in the cavities and not move about the flat areas, whereas individuals on Flat blocks changed position. Sea urchins in the Pit treatment consumed less food and had relatively larger demipyramids (the 'jaw' ossicle in Aristotle's lantern). These morphological and allometric changes occurred over a short time-period (8-20 weeks). We conclude that microhabitat is an important factor in controlling the behavior and growth dynamics of the bioeroding sea urchin S. purpuratus.

  10. REVISIÓN DE LOS BIOCOREMAS MARINOS GLOBALES DEL JURÁSICO SEGÚN LA DISTRIBUCIÓN DE LOS MOLUSCOS BIVALVOS

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    Damborenea, Susana E.

    2017-11-01

    Full Text Available Numerosos trabajos regionales o locales han propuesto el reconocimiento de unidades biogeográficas de distintos rangos (biocoremas basadas sobre la distribución de los moluscos bivalvos para el Jurásico, pero no existía una síntesis a nivel mundial. Este trabajo es una revisión de las más significativas de esas propuestas, en un intento de lograr una síntesis de los patrones biogeográficos globales desde el Jurásico Temprano al Tardío, mientras se producían cambios sustanciales en la paleogeografía de la Tierra y los patrones de circulación oceánica como resultado de la disgregación de Pangea. Se hace también un breve análisis de la evolución en el tiempo y el espacio de cada una de las principales unidades reconocidas y de sus relaciones. Estos biocoremas pueden agruparse en tres unidades de primer orden que han tenido continuidad en el tiempo: Boreal, Tethys y Austral. Las unidades revisadas aquí han sido reconocidas y caracterizadas de forma muy heterogénea por los distintos autores, pero los criterios básicos más utilizados incluyen desde el grado de endemismo y la diversidad relativa, hasta las afinidades paleobiogeográficas de los taxones a nivel genérico. Los patrones de distribución de los bivalvos jurásicos no solamente son claves para entender cuestiones puramente biogeográficas, sino que han sido utilizados como argumento y evidencia en discusiones de índole paleogeográfica (como el establecimiento de corredores oceánicos, o patrones de circulación marina superficial, e incluso son pruebas de peso para la discusión de tópicos paleotectónicos, como la localización de terrenos desplazados y la deriva continental.

  11. The role of Argopecten purpuratus shells structuring the soft bottom community in shallow waters of southern Peru

    Science.gov (United States)

    Lomovasky, Betina J.; Gamero, Patricia A.; Romero, Leonardo; Firstater, Fausto N.; Gamarra Salazar, Alex; Hidalgo, Fernando; Tarazona, Juan; Iribarne, Oscar O.

    2015-12-01

    Accumulation of Argopecten purpuratus shells often occurs after El Niño events in shallow waters of Independencia Bay (14°17‧S-76°10‧W; Pisco, Peru). Here we experimentally investigate the effects of their shell accumulation on macrobenthos assemblages in soft bottom, shallow areas of the bay. A field experiment (from May 2006 to May 2007), including four treatments with different coverage levels of empty shells of A. purpuratus, were randomly arranged in: (1) areas devoid of shells ("Empty" treatment: experimental control), (2) 50% of the plot area covered with shells haphazardly distributed over the bottom ("medium" treatment), (3) 100% of the plot area covered with shells, forming a 10 cm valve layer ("full" treatment) and (4) "natural control". We found a total of 124 taxa throughout the experiment. Polychaetes, crustaceans and mollusks were the most abundant groups in "natural controls", dominated by the gastropod Nassarius gayi and the polychaetes Prionospio peruana, Platynereis bicanaliculata and Mediomastus branchiferus. The abundance of individuals (N) and the species richness (S) were higher in the "medium" treatment, but only in one month under positive sea bottom thermal anomalies. Similarity analysis (Bray-Curtis) showed that "natural control", "empty" and "full" treatments were more similar among them than the "medium" treatment. Multidimensional analysis showed no clear species association among treatments and a higher grouping among the samplings of Jun-06, Aug-06 and Nov-06. Our results also showed that the commercial crab Romaleon polyodon and the polyplacophora Tonicia elegans were positively affected by shell accumulations ("medium" treatment), while the limpet Fissurella crassa was negatively affected. Our study shows that directly by changing habitat structure or indirectly by changing sediment characteristics, the addition of scallop shells to the soft bottom can modify the macrobenthic assemblage; however, the seasonal oceanographic

  12. La bioénergétique du pétoncle péruvien (Argopecten purpuratus) dans un contexte environnemental limitant en oxygène

    OpenAIRE

    Aguirre-Velarde , Arturo

    2016-01-01

    During the past two decades, the scallop (Argopecten Purpuratus) culture developed in the Peruvian coastal bays. The trophic availability linked to the upwelling system supports the production scallop. However, the Peruvian coasts are also known to have a high environmental variability especially in oceanic domain. Although scallop farms are vulnerable to production hazards (mortality, low growth), environmental variability in coastal bays of Peru and its effects on growth, reproduction and s...

  13. Developmental expression of a cell surface protein involved in sea urchin skeleton formation. [Strongylocentrotus purpuratus; Lytechinus pictus

    Energy Technology Data Exchange (ETDEWEB)

    Farach, M.C.; Valdizan, M.; Park, H.R.; Decker, G.L.; Lennarz, W.J.

    1986-05-01

    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 (/sup 3/H) 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.

  14. Elimination of vibrio cholerae El Tor, in scallops (Argopecten purpuratus) by gamma radiation and product organoleptic evaluation

    International Nuclear Information System (INIS)

    Torres, Z.; Bernuy, B.; Vivanco, M.; Kahn, G.

    1999-03-01

    V. cholerae D 10 value in scallops (Argopecten purpuratus) was determined in vivo. D 10 was found to be 0,143 kGy, requiring therefore the application of 8D in scallops, equivalent to a 1,14 kGy dose, the optimal dose for life span extension of samples kept under refrigeration conditions (0-1 o ), and examined periodically under different analytic method criteria. Life span for the appearance characteristic reaches the acceptability limit of 3, after 11 days for control samples, and 16 and 13 days for samples radiated at 1 and 2 kGy. Smell of control samples was accepted only until the 13 th day while samples radiated at 1 and 2 kGy went beyond this level, reaching 19 and 17 days respectively. In the same way, life span for the flavor characteristic was extended to 19 and 20 days for samples radiated at 1 and 2 kGy, respectively, while control samples only reached 15 days. Control sample texture remained within acceptable limits until the 18 th day, whereas samples radiated at 1 and 2 kGy reached 21 and 17 days, respectively. Use of ph and nitrogen volatile bases were also evaluated as quality indicators. (authors)

  15. Aplicación de dos biomarcadores para el análisis de lesiones en el DNA de bivalvos marinos

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    Giovanna Sotil

    2013-05-01

    Full Text Available El presente trabajo describe la estandarización de las técnicas del Test de Micronúcleo (MN y Ensayo Cometa para la evaluación del daño en el DNA de bivalvos marinos. La importancia de estas técnicas radica en que permiten evaluar la respuesta temprana al estrés ocasionado por agentes contaminantes y cambios ambientales. Tejidos branquiales de Semimytilus algosus y Aulacomya ater fueron utilizados para tratamientos in vivo e in vitro. Los tejidos fueron expuestos a los agentes mutagénicos Mitomicina C en concentraciones de 0,02; 0,04 y 0,06 x 10-6 M y H2 O2 en una concentración de 100 μM con tiempos de evaluación de 1, 3, 6, 24 y 48 h. Diferentes soluciones para la colecta del tejido y aislamiento celular fueron evaluados obteniendo una mayor viabilidad celular en la solución salina CMFS, pH 7,3; en frío. El Test de Micronúcleo se modificó en la forma de obtener el disgregado celular, realizando la hipotonización en Citrato de sodio 0,9%, fijación en metanol por segundos posterior al frotis y la tinción con Giemsa 2%. La estandarización del Ensayo Cometa Alcalino, descrita por Wilson et al. (1998, se realizó modificando la suspensión celular en agarosa LMP (1% en solución Kenny, pH 7,5, la exposición a solución de lisis (pH 10 con DMSO y Tritón con variaciones en el tiempo de 1 a 16 h, y la electroforesis en solución alcalina pH 13,7 y tinción con Bromuro de etidio y Nitrato de plata para geles de agarosa. Los cambios realizados en ambas técnicas permitieron obtener un alto número celular con morfología definida, observándose macrolesiones como la formación de MN y aberraciones nucleares, y la determinación cualitativa de microlesiones observadas por fragmentación y migración del DNA.

  16. Comparación del crecimiento de Argopecten purpuratus entre cohortes obtenidas de captación de larvas en ambiente natural y de hatchery Comparison of growth among cohorts obtained Argopecten purpuratus larval recruitment in natural and hatchery

    Directory of Open Access Journals (Sweden)

    Eduardo P Pérez

    2012-11-01

    Full Text Available En Chile los cultivos del ostión del norte Argopecten purpuratus han sido desarrollados intensivamente a partir de la captación de semillas en ambiente natural y desde principios de 1980 con semillas obtenidas en hatchery. Para aportar información sobre el desempeno de semillas de ostión del norte en este estudio se comparó, mediante ANCOVA, el crecimiento en longitud entre cohortes producidas a partir de semillas de ambiente natural y de hatchery en Tongoy, Chile. Se evaluó la consistencia de esta comparación en distintos anos y estaciones, comparándose parejas de cohortes producidas simultáneamente en los anos 2003 (primavera, 2005 (invierno y 2006 (verano. El análisis estadístico mostró que existen diferencias estadísticas significativas entre cohortes obtenidas en ambiente natural y aquellas obtenidas en hatchery. La prueba de Tukey evidenció diferencias significativas entre CN2003 y CH2003 como también entre CN2005 y CH2005, pero no así entre CN2006 y CH2006. Estas diferencias indican que las cohortes de semillas de ambiente natural crecieron más rápido que las de hatchery. La comparación interanual evidenció diferencias estadísticas significativas. Estos resultados son discutidos a la luz de dos factores: la temperatura de cultivo y la heterocigocidad de la población de cultivo.In Chile crops of the northern scallop Argopecten purpuratus have been developed intensively from seeds obtained in natural environment, and since 1980 from hatchery's seed, when this technique could be controlled and developed. In order to provide information on the performance of seeds of northern scallops in this study growth in length between cohorts produced from seeds obtained in natural environment (CN and hatchery (CH in Tongoy (Chile was compared using ANCOVA. We assessed the consistency of this comparison in different years and seasons. The compared cohorts are pairs of cohorts produced simultaneously in the years 2003 (spring, 2005

  17. Crecimiento y estructura demográfica de Argopecten purpuratus en la Reserva Marina La Rinconada, Antofagasta, Chile

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available Se presentan los parámetros de crecimiento L∞ = 120.38 mm y K = 0.9668 para el banco de Argopecten purpuratus de la Reserva Marina La Rinconada (Antofagasta, Chile, obtenidos entre marzo de 2001 y mayo de 2003 usando métodos de marcaje y recaptura de ejemplares. La elevada recaptura de individuos marcados (60–80% indica baja mortalidad natural y una conducta sedentaria del recurso. Las evaluaciones anuales realizadas para estimar el tamaño del banco confirmaron tal conducta, encontrándose la mayoría de los individuos agregados en el centro, con densidades que variaron entre años de 9 a 14.8 ind m–2. La abundancia de ejemplares también mostró variabilidad interanual, con cifras de 10.1 × 106 en 2001, 8.2 × 106 en 2002 y 12.4 × 106 en 2003. Estas evaluaciones mostraron, además, una disminución en la talla media de la estructura demográfica del banco entre un año y otro, reduciéndose de 75.8 mm en 2001 a 62.1 mm en 2002 y a 51.7 mm en 2003. Esta disminución también ocurrió con el número de ejemplares mayores o iguales a la talla mínima legal (90 mm, reduciéndose de 2.6 × 106 ejemplares presentes en 2001 a 3.7 × 105 ejemplares en 2003. La aplicación de los parámetros de crecimiento sobre la estructura poblacional del banco entre 2002 y 2003 señaló la integración de una nueva clase anual de 6.5 × 106 de ejemplares en 2002 y de 11.2 × 106 de individuos en 2003. El descuento de estas cifras, del número total de ejemplares presentes en ambos años, demuestra una pérdida cercana a los 8.4 × 106 de ostiones en 2002 y de cerca de 7.0 × 106 de individuos en 2003. Estas pérdidas correspondieron a ejemplares con tallas superiores a los 60 mm, lo cual es corroborado con el análisis de la curva de captura realizado con el programa Fisat, cuyos resultados señalan una mortalidad Z = 2.15 en 2002 para el segmento de la población entre 67.5 y 115.5 mm, y Z = 3.08 en 2003 para el segmento de 64.3 a 112.5 mm. Los

  18. Composición y estructura de la macrofauna asociada con agregaciones de dos especies de bivalvos en Isla de Cubagua, Venezuela Composition and structure of the macrofauna associated with beds of two bivalve species in Cubagua Island, Venezuela

    Directory of Open Access Journals (Sweden)

    Iván Hernández-Ávila

    2013-06-01

    Full Text Available Las agregaciones de bivalvos constituyen un microhábitat para una gran variedad de organismos en el ambiente intermareal, submareal y en aguas profundas. Agregaciones de la ostra perla (Pinctada imbricata y pepitona (Arca zebra a diferentes densidades poblacionales se evaluaron para determinar la composición y estructura comunitaria de la macrofauna asociada en tres taxa (Crustacea Decapoda, Mollusca y Echinodermata. La hipótesis nula de no diferencias en descriptores univariados y multivariados fue probada comparando la fauna asociada entre las agregaciones de las dos especies a tres niveles de densidad. En estas agregaciones se identificaron 102 especies de 55 familias. Mithraculus forceps (Majidae, Crucibulum auricula (Calyptraeidae y Ophiotrix angulata (Ophiothrichidae fueron las especies más comunes encontradas en estas asociaciones. Las densidades medias y altas de las agregaciones de bivalvos presentaron mayor número de especies, abundancia, diversidad de Shannon, equidad, diversidad taxonómica y distinción taxonómica de la fauna asociada que las agregaciones de baja densidad poblacional. Análisis multivariados detectaron diferentes estructuras de los ensambles de la fauna asociada en agregaciones de bivalvos con densidad baja en comparación con los de densidad media y alta. Adicionalmente no se detectaron diferencias en la fauna asociada entre las especies. La densidad de las agregaciones de bivalvos, asociada a la complejidad topográfica, es un factor importante para la composición de la fauna asociada.Bivalve aggregations constitute a microhabitat for a wide variety of organisms in intertidal, subtidal and deep-water marine benthic habitats. Increase in density of bivalve beds could offer more crevices and substratum for the associated fauna, affecting community composition. Beds of the Atlantic Pearl Oyster (Pinctada imbricata and the Turkey Wing (Arca zebra of contrasting population densities were evaluated to determine

  19. The effects of copper and nickel on the embryonic life stages of the purple sea urchin (Strongylocentrotus purpuratus).

    Science.gov (United States)

    Tellis, Margaret S; Lauer, Mariana M; Nadella, Sunita; Bianchini, Adalto; Wood, Chris M

    2014-10-01

    The aim of this research was to generate data on the mechanisms of toxicity of copper [Cu (4-12 µg/L)] and nickel [Ni (33-40 µg/L)] during continuous sublethal exposure in seawater (32 ppt, 15 °C) in a sensitive test organism (Strongylocentrotus purpuratus) at its most sensitive life stage (developing embryo). Whole-body ions [calcium (Ca), sodium (Na), potassium (K), and magnesium (Mg)], metal burdens, Ca uptake, and Ca ATPase activity were measured every 12 h during the first 72-84 h of development. Ionoregulatory disruption was clearly an important mechanism of toxicity for both metals and occurred with minimal metal bioaccumulation. Most noteworthy was a significant disruption of Ca homeostasis, which was evident from an inhibition of unidirectional Ca uptake rates, whole-body Ca accumulation, and Ca ATPase activity intermittently during 72-84 h of development. At various times, Cu- and Ni-exposed embryos also displayed lower levels of K and increased levels of Na suggesting inhibition of Na/K ATPase activity. Greater levels of Mg during initial stages of development in Cu-exposed embryos were also observed and were considered a possible compensatory mechanism for disruptions to Ca homeostasis because both of these ions are important constituents of the developing spicule. Notably, most of these effects occurred during the initial stages of development but were reversed by 72-84 h. We therefore propose that it is of value to study the toxic impacts of contaminants periodically during development before the traditional end point of 48-72 h.

  20. Analysis of the DNA binding proteins interacting with specific upstream sequences of the S. purpuratus CyI actin gene.

    Science.gov (United States)

    Ganster, R; Paul, H; Katula, K S

    1992-12-01

    The CyI actin gene of the sea urchin, Strongylocentrotus purpuratus, is regulated temporally and spatially within the cells of the early embryo. In an effort to understand the molecular basis for the CyI actin pattern of expression, we have begun analyzing the protein-DNA interactions within regions previously shown to be of potential functional importance (Katula et al., 1987). Using DNase I footprinting, 10 protected regions were identified containing both conserved and apparently novel protein binding sites. Gel mobility shift competition assays confirmed the presence of multiple protein factors which specifically recognize CyI actin upstream sequences. Determination of a relative affinity constant value (Kr) indicated that most of the protein factors preferred their respective oligonucleotide sequences vs. a synthetic competitor DNA in a range of 10(4). The highest affinity binding was observed for proteins binding to the oligonucleotide probe containing the octamer element (Kr approximately 10(6)). Heterologous gel shift competition assays were carried out to investigate the interrelatedness of the protein factors. These studies, combined with other data, indicate there are both unique and redundant protein-DNA interactions in the region being examined. Possible alterations in CyI actin DNA binding proteins were investigated during the period of CyI transcriptional activation by gel mobility shift analysis. An increase in binding activity was observed for most of the factors, indicating that early transcriptional activity of CyI actin may involve a general increase in the amount or activity of specific transcription factors. In addition, qualitative changes, as seen by alterations in the shift patterns, were observed for some of the oligonucleotide probes.

  1. A pancreatic exocrine-like cell regulatory circuit operating in the upper stomach of the sea urchin Strongylocentrotus purpuratus larva.

    Science.gov (United States)

    Perillo, Margherita; Wang, Yue Julia; Leach, Steven D; Arnone, Maria Ina

    2016-05-26

    Digestive cells are present in all metazoans and provide the energy necessary for the whole organism. Pancreatic exocrine cells are a unique vertebrate cell type involved in extracellular digestion of a wide range of nutrients. Although the organization and regulation of this cell type is intensively studied in vertebrates, its evolutionary history is still unknown. In order to understand which are the elements that define the pancreatic exocrine phenotype, we have analyzed the expression of genes that contribute to specification and function of this cell-type in an early branching deuterostome, the sea urchin Strongylocentrotus purpuratus. We defined the spatial and temporal expression of sea urchin orthologs of pancreatic exocrine genes and described a unique population of cells clustered in the upper stomach of the sea urchin embryo where exocrine markers are co-expressed. We used a combination of perturbation analysis, drug and feeding experiments and found that in these cells of the sea urchin embryo gene expression and gene regulatory interactions resemble that of bona fide pancreatic exocrine cells. We show that the sea urchin Ptf1a, a key transcriptional activator of digestive enzymes in pancreatic exocrine cells, can substitute for its vertebrate ortholog in activating downstream genes. Collectively, our study is the first to show with molecular tools that defining features of a vertebrate cell-type, the pancreatic exocrine cell, are shared by a non-vertebrate deuterostome. Our results indicate that the functional cell-type unit of the vertebrate pancreas may evolutionarily predate the emergence of the pancreas as a discrete organ. From an evolutionary perspective, these results encourage to further explore the homologs of other vertebrate cell-types in traditional or newly emerging deuterostome systems.

  2. Effects of an oil production effluent on gametogenesis and gamete performance in the purple sea urchin (Strongylocentrotus purpuratus Stimpson)

    International Nuclear Information System (INIS)

    Krause, P.R.

    1994-01-01

    Adult organisms subjected to chronic discharges from a point source of pollution may exhibit several sublethal responses. One such response is the impairment of gamete production. This may be expressed in the amount and/or quality of gametes produced by adults. In this study the effects of chronic exposure to produced water (an oil production effluent) on the gametogenesis and gamete performance of the purple sea urchin (Strongylocentrotus purpuratus Stimpson) were examined using an in situ caging experiment. Adult purple sea urchins were kept in benthic cages arrayed down-field from a discharging diffuser at 13 sites, with distances ranging from 5 to 1,000 m. Cage exposures were maintained in the field for eight weeks, and each cage held 25 animals. Gametogenesis was examined for each sex by comparing a size-independent measure of relative gonads ass as determined by analysis of covariance. Results showed that there was a significant negative relationship between these estimates of relative gonad mass and distance from the outfall for both sexes, indicating that sea urchins living closer to the outfall produced significantly larger gonads. Gamete performance was measured through a fertilization kinetics bioassay that held the concentration of eggs constant and varied the amount of sperm added. The proportion of eggs fertilized under each sperm concentration was determined and the response fit to a model of fertilizability showed a positive relationship with distance away from the outfall. These findings indicate that although adult sea urchins exposed to a produced water outfall exhibit larger gonads, they suffer a marked decrease in a gamete performance

  3. Confirmación molecular de tres especies de bivalvos xilótrofos (Familia Teredinidae en las bahías de Cartagena y Barbacoas, mar Caribe, Colombia

    Directory of Open Access Journals (Sweden)

    Michael Ahrens

    2013-12-01

    Full Text Available A pesar de la existencia de un extenso hábitat de manglares en Colombia, solo unos pocos estudios han descrito la diversidad de bivalvos teredinidos xilótrofos (conocidos como “broma” en el país. El presente estudio investigó la presencia de bivalvos teredinidos en las bahías de Cartagena y Barbacoas. En un estudio de campo llevado a cabo en marzo de 2013, diez individuos de dos géneros de Teredinidae, correspondientes morfológicamente a Neoteredo reynei y Bankia spp., fueron encontrados en las raíces sumergidas de mangle rojo (Rhizophora mangle. Identificaciones morfológicas iniciales se complementaron con identificación molecular. Para esto, dos fragmentos de genes fueron secuenciados: 588 pares de bases (pb del gen mitocondrial citocromo oxidasa subunidad 1 (CO1 y 305 pb del gen nuclear de la subunidad ribosómica pequeña (18S. Búsquedas de alineación básica (BLAST y árboles filogenéticos utilizando secuencias de CO1 y 18S de otras especies de Teredinidae públicamente disponibles y no publicadas confirmaron la identidad de Neoteredo reynei en la bahía de Barbacoas. En contraste, las secuencias obtenidas para Bankia, indicaron la presencia de dos especies distintas en la bahía de Cartagena. La confirmación de al menos tres especies de Teredinidae en las bahías de Cartagena y Barbacoas sugiere la presencia de especies adicionales y justifica un mayor esfuerzo de muestreo para este grupo de descomponedores de madera tan importante ecológica y económicamente.

  4. Sclerochronological records and daily microgrowth of the Peruvian scallop (Argopecten purpuratus, Lamarck, 1819) related to environmental conditions in Paracas Bay, Pisco, Peru

    Science.gov (United States)

    Aguirre Velarde, Arturo; Flye-Sainte-Marie, Jonathan; Mendo, Jaime; Jean, Fred

    2015-05-01

    We investigated the rhythm of micro-striae formation in the shell of Argopecten purpuratus and environmental influence on micro-growth increments by monitoring growth over a 98-day period between April and July 2007 under bottom and suspended culture (2 m above the bottom) rearing conditions. The transfer of individuals to the study site induced the formation of a notable growth mark that allowed us to count the number of micro-striae formed between transfer and sampling dates. Micro-striae counts showed a deposition rate of one stria per day independent of rearing condition. This result allowed us to analyse the relationships between growth increments and environmental conditions. We therefore examined the deviations between observed growth rates and growth rates predicted from a Von Bertalanffy growth function. Cross-correlation analysis revealed significant correlations, without time-lag, between these deviations and both particulate organic carbon and nitrogen concentrations in the bottom treatment. Additionally, we observed negative correlations with temperature and current speed at this depth with time-lags of 1 and 10 days respectively. In the suspended treatment, we observed a significant negative correlation with temperature, only with a 12-day lag-time. Our results show that growth response to environmental variability is not always instantaneous. This delay can be explained by the time delay over which metabolic processes need to be performed (e.g. digestion, use/movements of reserves, growth, reproduction). Further modeling studies could help to better understand these processes.

  5. The elemental composition of purple sea urchin (Strongylocentrotus purpuratus calcite and potential effects of pCO2 during early life stages

    Directory of Open Access Journals (Sweden)

    M. LaVigne

    2013-06-01

    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 (e.g. magnesium into the crystal lattice of these skeletal structures, a process that is sensitive to a variety of biological and environmental factors. Here we explore 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-Mg 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 spanning a range of carbonate chemistry conditions (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 μatm; pHT = 8.02 ± 0.03 1 SD; Ωcalcite = 3.3 ± 0.2 1 SD. However, when reared under elevated pCO2 (900 μatm; pHT = 7.73 ± 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

  6. Short-term feeding response of the mussel Mytilus chilensis exposed to diets containing the toxic dinoflagellate Alexandrium catenella Respuesta alimentaria inicial del bivalvo Mytilus chilensis expuesto a dietas conteniendo el dinoflagelado tóxico Alexandrium catenella

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    JORGE M NAVARRO

    2008-03-01

    Full Text Available The short-term feeding response of the bivalve Mytilus chilensis was measured using four diets containing different proportions of the toxic dinoflagellate Alexandrium catenella. The diets containing the highest concentrations of the dinoflagellate showed the greatest effect on the feeding activity in the mussel, with clearance and ingestión rates significantly reduced during the first hours of exposure. After this period, M. chilensis demonstrated a capacity to acclimate to the toxic diets, with feeding parameters reaching values similar to those of untreated control organisms. It was not clear if the negative effect on the feeding behavior was caused by the presence of the paralytic toxin, or due to the larger size of the dinoflagellate cells in comparison with cells of Isochrysis galbana used in the control diet. However, parallel studies with diets containing the nontoxic dinoflagellate Alexandrium affine of similar size and shape to that of A. catenella, suggested the cell size was the main cause for impairment of feeding behavior. The capacity for acclimation to either toxin or cell size by M. chilensis makes it a good indicator species for the early detection of harmful PSP events, since its relative insensitivity to the toxin allows it to quickly recover normal feeding behavior and permits it to accumulate PSP in its tissues in a short timeLa respuesta inicial del bivalvo Mytilus chilensis fue medida bajo cuatro dietas que contenían diferentes proporciones del dinoflagelado tóxico Alexandrium catenella. Las dietas que contenían las concentraciones más altas de este dinoflagelado mostraron el mayor efecto durante las primeras horas de exposición. Después de este periodo inicial, M. chilensis demostró la capacidad para aclimatarse a estas dietas tóxicas, con parámetros de alimentación que alcanzaron valores similares a aquellos de los organismos controles. No fue claro si el efecto negativo sobre la conducta de alimentación fue

  7. Biomineralization changes with food supply confer juvenile scallops (Argopecten purpuratus) resistance to ocean acidification, supplement to: Ramajo, L; Marba, Núria; Prado, Luis; Peron, Sophie; Lardies, Marco A; Rodriguez-Navarro, Alejandro; Vargas, C A; Lagos, Nelson A; Duarte, Carlos M (2016): Biomineralization changes with food supply confer juvenile scallops (Argopecten purpuratus) resistance to ocean acidification. Global Change Biology, 22(6), 2025-2037

    KAUST Repository

    Ramajo, L

    2016-01-01

    Future ocean acidification (OA) will affect physiological traits of marine species, with calcifying species being particularly vulnerable. As OA entails high energy demands, particularly during the rapid juvenile growth phase, food supply may play a key role in the response of marine organisms to OA. We experimentally evaluated the role of food supply in modulating physiological responses and biomineralization processes in juveniles of the Chilean scallop, Argopecten purpuratus, that were exposed to control (pH 8.0) and low pH (pH 7.6) conditions using three food supply treatments (high, intermediate, and low). We found that pH and food levels had additive effects on the physiological response of the juvenile scallops. Metabolic rates, shell growth, net calcification, and ingestion rates increased significantly at low pH conditions, independent of food. These physiological responses increased significantly in organisms exposed to intermediate and high levels of food supply. Hence, food supply seems to play a major role modulating organismal response by providing the energetic means to bolster the physiological response of OA stress. On the contrary, the relative expression of chitin synthase, a functional molecule for biomineralization, increased significantly in scallops exposed to low food supply and low pH, which resulted in a thicker periostracum enriched with chitin polysaccharides. Under reduced food and low pH conditions, the adaptive organismal response was to trade-off growth for the expression of biomineralization molecules and altering of the organic composition of shell periostracum, suggesting that the future performance of these calcifiers will depend on the trajectories of both OA and food supply. Thus, incorporating a suite of traits and multiple stressors in future studies of the adaptive organismal response may provide key insights on OA impacts on marine calcifiers.

  8. Community structure of the macroinfauna in the sediments below an intertidal mussel bed (Mytilus chilensis (Hupe of southern Chile Estructura comunitaria de la macroinfauna en los sedimentos bajo un banco intermareal de bivalvos (Mytilus chilensis (Hupe en el sur de Chile

    Directory of Open Access Journals (Sweden)

    CRISTIAN DUARTE

    2006-09-01

    two separate from that of the other stations (i.e. located outside the mussel bed. Results of ANOVA showed significant differences for all sediment variables, with the exception of percentages of gravel particles and mean grain size of sands. The most noticeable difference was that shown by station 1 (lower contents of sand and higher content of mud, biogenic aggregates and total organic matter. The results of BIO-ENV routine showed that the best fit between the taxonomic composition of the macroinfauna and single sediment variables, was reached with percentages of sand and mud. It is concluded, that mussel beds of sedimentary bottoms of southern Chile have a significant role on the sediment quality and community structure of the macroinfauna, a probable combined effect of physiological processes (ingestion of larvae, biodeposition and the complex physical matrix of the bedEl bivalvo Mytilus chilensis (Hupe puede formar densos bancos en áreas sedimentarias de la costa protegida de los archipiélagos norpatagónicos de la costa de Chile (ca. 40-43º S. Durante el otoño del 2002, se recolectaron muestras replicadas en cinco estaciones en la zona intermareal de Panitao (Golfo de Reloncaví a lo largo de un transecto paralelo a la línea de marea baja y extendido desde el centro de un banco de bivalvos (estaciones uno y dos con 100 y ca. 25 % de cobertura, respectivamente hasta una zona libre de bivalvos (estaciones tres, cuatro y cinco. La macroinfauna estuvo dominada numéricamente por los grupos Polychaeta, Olygochaeta y Crustacea Peracarida. El número total de especies recolectadas fue 14, siendo las más abundantes el poliqueto Perinereis vallata, oligoquetos de la familia Tubificidae y el crustáceo anfípodo Corophium insidiosum. El número de especies, el índice de diversidad de Shannon-Wiener y la abundancia total de la macroinfauna no presentaron diferencias significativas entre las estaciones de muestreo. Sin embargo, la contribución porcentual de los

  9. Asociación entre la tasa de autofecundación y la frecuencia de larvas malformadas en poblaciones cultivadas del ostión del norte Argopecten purpuratus (Lamarck, 1819 Association between self-fertilization rates and the frequency of malformed larvae in farmed populations of the northern scallop Argopecten purpuratus (Lamarck, 1819

    Directory of Open Access Journals (Sweden)

    Christopher Concha

    2011-07-01

    Full Text Available El incremento de la frecuencia de malformaciones y la reducción de la viabilidad y fecundidad suelen ser las primeras manifestaciones de la depresión por consanguinidad en animales. El ostión del norte, Argopectenpurpuratus (Lamarck, 1819, es una especie hermnafrodita funcional con autofecundación parcial y durante la reproducción artificial puede presentar altos grados de autofecundación. En este trabajo se analizó la asociación de la tasa de autofecundación con la frecuencia de larvas malformadas y la supervivencia larval. Se desovaron adultos maduros y se recogieron separadamente los gametos femeninos del 5° pulso de liberación en adelante y los masculinos. Los ovocitos fueron fecundados con espermatozoides de otro individuo, formando familias de hermanos completos. La tasa de autofecundación se verificó por la proporción de ovocitos que entra en división en una muestra de ellos sin fecundar. La tasa de autofecundación varió entre familias de 0 a 100%, con distribución de frecuencias normal. La proporción de larvas malformadas se distribuyó al azar entre las familias analizadas, pero se correlacionó negativamente, en forma moderada pero significativa, con la tasa de autofecundación y la temperatura media del cultivo. Los datos sugieren que la autofecundación en las familias de ostiones puede favorecer una mayor homeostasis del desarrollo larval.Increased frequencies of malformations and the reduction of viability and fecundity are some of the first manifestations of inbreeding depression in animals. The northern scallop, Argopecten purpuratus (Lamarck, 1819, is a functional hermaphrodite species with partial self-fertilization. During artificial reproduction, this species may present high degrees of self-fertilization. In this work, the association between the selfing rate and the frequency of larval malformations and survival were analyzed. Mature adults were spawned, and female and male gametes were collected

  10. Is there redundancy in bioengineering for molluscan assemblages on the rocky shores of central Chile? ¿Existe redundancia en la bioingeniería de los ensambles de moluscos de las costas rocosas de Chile central?

    OpenAIRE

    BRENDAN P KELAHER; JUAN CARLOS CASTILLA; LUIS PRADO

    2007-01-01

    Bioengineers modify habitats via their own physical structures and substantially increase local diversity in marine ecosystems. On rocky shores, there are large overlaps in the composition of communities associated with bioengineers that form complex mat-like habitats. We investigated the potential for redundancy in habitat provision by these types of habitats by comparing diverse molluscan assemblages associated with Perumytilus purpuratus mussel beds and algal turfs of Corallina officinalis...

  11. Simulation model of the scallop (Argopecten purpuratus farming in northern Chile: some applications in the decision making process Modelo de simulación para el cultivo del ostión (Argopecten purpuratus en el norte de Chile: aplicaciones para la toma de decisiones

    Directory of Open Access Journals (Sweden)

    Renato Molina

    2012-09-01

    Full Text Available Aquaculture farming is a complex system integrating several disciplines, including biology, engineering and economics, all which need to be correctly intertwined to have a profitable and environmentally sustainable activity. During the past recent years, scallop (Argopectenpurpuratus farmers in northern Chile have come to comprehend the hard way that aquaculture producers operate in a complex and dynamic environment where natural and economic factors are in constant change. Thus, to keep a profitable and competitive business in today's world, aquaculture farm managers are in need of relatively easy to use tools for efficient and timely decision making. Harvest size and time, mortality and growth rates, stocking rates, costs and market prices are important variables and parameters to monitor, where decisions with respect to their levels or values have to be made. In this context, non-linear and dynamic quantitative bioeconomic models should become valuable tools, for periodic decision making in the aquaculture business. This paper shows how to emulate Chilean scallop farming using a simulation model that mimics some of the industry's features. The model presented here focuses on a scallop aquaculture center that uses the common technology approach of pearl net and lanterns of the northern region of Chile, and analyses the farming strategies based on harvesting size. Also, these strategies were subject to variations in the parameters in order to identify patterns and asses the sensibility of the model to input values.La acuicultura es un sistema complejo que integra varias disciplinas, incluyendo la biología, ingeniería y economía, las cuales deben ser correctamente entrelazadas para lograr una actividad rentable y ambientalmente sostenible. Durante los últimos anos, los cultivadores del ostión del norte (Argopecten purpuratus en Chile han comprendido de la peor manera, que las actividades de acuicultura operan en un entorno complejo y din

  12. Inactivation of Vibrio cholerae O1 El Tor inoculated into Peruvian ''choro'' mussels (Aulacomya ater) and two species of clams (Argopecten purpuratus and Gari solida) using medium-dose irradiation

    International Nuclear Information System (INIS)

    Torres, Z.; Bernuy, B.; Kahn, G.; Zapata, G.; Vivanco, M.; Guzman, E.; Leon, R.

    2001-01-01

    The radiation decimal reduction dose (D 10 ) for Vibrio cholerae O1 biotype El Tor inoculated through the natural feeding system into three species of bivalve mollusks from the Peruvian Pacific coast: ''choro'' mussels (Aulacome ater), ''abanico'' clams (Argopecten purpuratus), and common clams (Gari solida), was determined in vivo. The D 10 value obtained in vivo was 0.14 kGy in all mollusks tested. Concurrent studies conducted to determine the potential use of irradiation to extend the microbiological shelf-life of the mollusks during post-irradiation storage at 0-1 deg. C indicated that a dose of 1.0 kGy was optimal for choro mussels and abanico clams, whereas 2.0 kGy produced the best results when treating common clams. Shelf-life extension thus achieved was 31 days for choro mussels, 16 days for abanico clams, and 21 days for common clams. Non-irradiated control samples of all mollusks spoiled after 17 days of refrigerated storage. There were no significant (p<.05) adverse effects from the application of the optimal radiation treatments on the sensory characteristics (i.e. appearance, odor, flavor, and texture) of the mollusks. Total volatile basic nitrogen (VBN) and pH values were examined for use as indexes of seafood freshness. (author)

  13. Reproductive and larval cycle of the scallop Argopecten purpuratus (Ostreoida: Pectinidae, during El Niño-La Niña events and normal weather conditions in Antofagasta, Chile

    Directory of Open Access Journals (Sweden)

    Miguel Avendaño

    2008-03-01

    Full Text Available Seasonality, amplitude, and magnitude of spawning events were determined for Argopecten purpuratus in the La Rinconada marine reserve, Antofagasta, Chile, between December 1995 and January 2004. During the same period, samples of scallop larvae were obtained in vertical plankton hauls recovered within this reserve in an area routinely exposed to circular, gyre-like currents which helped retain the larvae within the bay. The reproduction of this population in normal or cool (e.g. "La Niña", 1998-2000 years occurred throughout the year, with a more active period between September and April, declining in June and August; this contrasted with the warmer "El Niño" oceanographic period of 1997-98 in which reproductive activity was more intense and prolonged throughout the entire year. The reproductive events in this population were mostly synchronous, although one asynchronous period occurred each year following the more intense March to May spawnings. This reproductive activity generated a continuous presence of larvae in the area in which no strict relation could be found between the intensities of spawning and numbers of larvae in the water. Larval presence was, however, generally correlated with active spawning periods. Important increases in larval numbers recorded at the end of 1999 and the beginning of 2003 were correlated with census data showing a higher percentage presence of broodstock over 90 mm in shell length during these years. An adequate stock of this size class is needed for a successful seed capture program in the reserve (for mass culture. Rev. Biol. Trop. 56 (1: 121-132. Epub 2008 March 31.Entre 1995 y 2004 se determinó, con el índice gonadosomático, el ciclo reproductivo de Argopecten purpuratus en La Rinconada, Antofagasta, Chile. Paralelamente se realizaron muestreos larvales mediante arrastres verticales de plancton. La reproducción, en años normales y fríos (La Niña, 1998-2000, ocurre todo el año, con un período m

  14. Patrones de colonización y ecología de poblaciones de dos bivalvos invasores (mejillón cebra Dreissena polymorpha Pallas, 1771 y almeja asiática Corbicula fluminea Müller, 1774 en un tramo lótico del Ebro medio (Castejón, Navarra.

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    MORALES, J., FLECHOSO, F., LIZANA, M., NEGRO, A.

    2013-01-01

    Full Text Available Los bivalvos dulceacuícolas son un componente importante de la ecología fluvial, fundamentalmente por el papel que desempeñan como organismos filtradores y de remoción del sedimento. Además son un grupo zoológico diverso y amenazado a escala global, en el que se incluyen algunas de las especies invasoras más dañinas. El estudio de sus poblaciones es imprescindible para conocer el estado de conservación de las comunidades bentónicas. Para esto se prospectaron 17 parcelas vadeables y 7 escolleras a lo largo de 7,38 km de meandros del río Ebro en Castejón (Navarra, tanto el cauce principal como en brazos secundarios de corriente permanente y/o temporal. El mejillón cebra Dreissena polymorpha Pallas, 1771 se encontró en 7 escolleras y 6 parcelas. El sustrato preferente fueron rocas (85%, donde la densidad resultó 0,31-5,45 mejillones/m2; el 2,6% se hallaron sobre plásticos agrícolas abandonados. En las escolleras sólo el 3,6% de los ejemplares eran juveniles y un 33% tenían una edad > 4 años. La almeja asiática Corbicula fluminea Müller, 1774 se encontró en todas las parcelas. La densidad resultó muy diferente en los tres tipos de ambientes fluviales con valores máximos de 15.100 almejas/m2, lo que constituye un nuevo máximo fluvial en Europa. Se encontraron subpoblaciones de almeja asiática con diferentes estructuras de edad según los ambientes fluviales, además de poblaciones menos numerosas en el brazo principal del río que en los otros tipos. Los resultados muestran que junto a estas especies alóctonas en expansión, con altas tasas de reclutamiento, se encuentra una estructura poblacional muy precaria para las autóctonas, de las cuales únicamente se localizaron 12 náyades vivas y ningún esférido.

  15. Las comunidades de mitilidos del mediolitoral rocoso del departamento de Lima

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    Carlos Paredes

    2014-06-01

    Full Text Available Se estudiaron 34 muestras de los conglomerados de mitilidos de la zona medio litoral rocosa del Departamento de Lima, (10°45'38"S a 12°57'39"S, tomadas periódicamente, entre junio y noviembre de 1972. Utilizando el método del índice biológico, se determinó la existencia de dos comunidades: Comunidad de Perumytilus purpuratus (Lamarck, 1819, en el horizonte medio de la zona mediolitoral. Comunidad de Semimytilus algosus (Gould, 1850, en el horizonte inferior de la zona mediolitoral.

  16. Aspectos ecologicos de las algas marinas de la provincia de Concepcion, Chile

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    Krisler Alveal

    1980-12-01

    Full Text Available Studies carried out in various localities of the Province of Concepción, Chile (36º40'S; 70º06'W estabilished the existence of two principal patterns of zonation defined by the populations of Mastocarpus sp. (¿ ?, Tridaea laminarioides, Gelidium pussilum, Ulva lactuca and Perumytilus purpuratus which occupy the lower hydrolittoral. In submerged levels the populations of Gracilaria and Macrocystis. form growths of moderate dimensions and in shallow waters, Iridaea ciliata, Gymnogongrus furcellatus and Gigartina chamissoii in scatterd patches.

  17. Rocky Intertidal Zonation Pattern in Antofagasta, Chile: Invasive Species and Shellfish Gathering

    Science.gov (United States)

    Castilla, Juan Carlos; Manríquez, Patricio H.; Delgado, Alejandro; Ortiz, Verónica; Jara, María Elisa; Varas, Manuel

    2014-01-01

    Background Biological invasions affecting rocky intertidal zonation patterns, yield information on species interactions. In the Bay of Antofagasta, northern Chile, the non-indigenous tunicate Pyura praeputialis, originally from Australia, has invaded (in the past century or so) and monopolized a major portion of the mid-intertidal rocky shore, displacing upshore the native mussel Perumytilus purpuratus. In Antofagasta the tunicate is subjected to intensive exploitation. Monitoring protocols show that in the past 10 years Antofagasta's tunicate population has experienced a drastic decline, affecting the intertidal zonation pattern. Methodology/Principal Findings A 12.5 km of coastline, on the southern eastern shore of the Bay of Antofagasta, was studied. Eight sites were systematically (1993–1994) or sporadically (2003–2014) monitored for the seaward-shoreward expansion or reduction of the tunicate Pyura praeputialis, and native mussel and barnacle bands. A notable reduction in the mid-intertidal band of P. praeputialis and a seaward expansion of the mussel, Perumytilus purpuratus, and barnacle bands was observed. We suggest that the major cause for the decline in the tunicate is due to its intensive exploitation by rocky shore Pyura-gathers. The rate of extraction of tunicates by professional Pyura-gathers ranged between 256–740 tunicates hour−1. Between 2009–2014 the density of professional Pyura-gather ranged between 0.5–4.5 km−1 per low tide. Hence, 10 professional Pyura-gathers working 1 h for 10 low tides per month, during 6 months, will remove between 307–888 m2 of tunicates. A drastic decline in tunicate recruitment was observed and several P. praeputialis ecosystems services have been lost. Conclusion and Significance In Antofagasta, the continuous and intensive intertidal gathering of the invasive tunicate Pyura praeputialis, has caused a drastic reduction of its population modifying the zonation pattern. Thereby, native mussel Perumytilus

  18. Variability of cadmium, copper and zinc levels in molluscs and associated sediments from Chile.

    Science.gov (United States)

    De Gregori, I; Pinochet, H; Gras, N; Muñoz, L

    1996-01-01

    The concentrations of cadmium, copper and zinc in mussel and sediment samples collected together from eight different geographical coastal areas of Chile were determined. The mussels studied were 'Chorito Maico', 'Almejas' and 'Navajuelas Chilenas' (Perumytilus purpuratus, Semelle solida and Tagellus dombeii, respectively). Sampling was carried out in July and September 1992 and January and April 1993 (winter, spring, summer and autumn seasons in Chile, respectively). The metal levels in these mussels varied among species; there were several sites where the metal concentrations in molluscs approached or exceeded the criteria levels for Cd, Cu and Zn in shellfish products: 1, 10 and 50 ppm ww respectively, which are regarded as safe levels for human consumption. The results of metal levels in sediments showed two areas clearly polluted with Cu. Strong relationships between Cu concentrations in the three molluscs and sediments were found; weak correlations were observed for Zn in S. solida.

  19. Fijacion primaria y variaciones morfologicas, durante la metamorfosis de algunos bivalvos chilenos

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    Juan Uribe Barichivith

    1980-12-01

    Full Text Available The larval primary settlement and the changes originated during the metamorphosis of some species of Chilean bivalves, are comparatively studied, being described, the larval and post - larval stages from the veliconcha to late plantigrade. By observing in ropes "anchovetera" nets and plankton samples, in the mitiliculture of Codihué (41º 46'S; 73º 24'W, it was verified for Mytilus chilensis Hupé, 1854 and Aulacomya ater (Molina, 1782, primary settlement on the filamentous algae of genera Enteromorpha with an average size of 33º µ high, minimum average of definitive settlement, byssus positional changes, etc. Information concerning average and number of larval and post - larval attachment to different deep and inmersión period and morphological characters of larval and post - larval of: Bankia martensi Stempell, 1898 (Teredinidae, Pholas chiloensis (Molina, 1782 (Pholadidae y Chlamys patriae Doello Jurado, 1918 (Pectinidae, are also given.

  20. The life cycle of Prosorhynchoides carvajali (Trematoda: Bucephalidae) involving species of bivalve and fish hosts in the intertidal zone of central Chile.

    Science.gov (United States)

    Muñoz, G; Valdivia, I; López, Z

    2015-09-01

    We describe the life cycle of the bucephalid Prosorhynchoides carvajali from the intertidal rocky zone of central Chile. To elucidate the life cycle of this digenean, two mytilid bivalves, Semimytilus algosus and Perumytilus purpuratus, and ten intertidal fish species belonging to the families Blenniidae, Tripterygiidae, Labrisomidae, Kyphosidae and Gobiesocidae were analysed for natural infections. In addition, experimental infections of fish were undertaken and molecular analyses were performed of several developmental stages of the digeneans in various host species. Experimental infections of fish were made from infected mytilids to determine which fish species were suitable for the metacercarial stage of Prosorhynchoides. We also determined the abundance and prevalence of metacercariae in natural infections in fish and found that they were lower than in the experimental infections. A molecular analysis showed that sporocysts from S. algosus were identical to metacercariae from five fish species and P. carvajali adults. Sporocysts isolated from P. purpuratus were similar to metacercaria found in one fish species only (G. laevifrons) but were different from P. carvajali, with 1.9-2.0% genetic divergence. Therefore, the complete life cycle of P. carvajali consists of the mytilid species S. algosus as the first intermediate host, at least five intertidal fish species as second intermediate hosts (Scartichthys viridis, Auchenionchus microcirrhis, Hypsoblennius sordidus, Helcogrammoides chilensis and Gobiesox marmoratus), two carnivorous fish as definitive hosts (Auchenionchus microcirrhis and A. variolosus) and one occasional definitive host (Syciases sanguineus). This is the second description of a life cycle of a marine digenean from Chile.

  1. Community structure of intertidal boulder-cobble fields in the Straits of Magellan, Chile

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    Carlos Ríos

    1999-12-01

    Full Text Available Based on quantitative samples taken along 4 transects in mobile hard-bottom intertidal areas of the Canal Whiteside, Magellan region, biotic composition, abundance and distribution patterns are described. The intertidal substrates, mainly formed by boulders and cobbles, represent highly heterogenous habitats from the structural point of view, and demonstrated a species richness higher than previously mentioned in some preliminary reports. Community structure parameters (abundance, species richness, diversity, and evenness were not homogenous in the study areas, suggesting local dynamics. Differences in the vertical distribution of organisms were also found, suggesting changes of the zonation pattern along the beach profile. The macrofaunal assemblages were dominated by few species, with different specific compositions between transects. In general, representatives of Mollusca (Mytilus chilensis, Perumytilus purpuratus, Polychaeta (Hemipodus simplex, and Amphipoda (Paramoera fissicauda, P. brachyura, Transorchestia chilensis were the numerically dominant groups. In terms of biomass, molluscs were highly dominant, mainly M. chilensis and P. purpuratus. Among the macroalgae, rhodophytes were the group with the highest presence, but Ulva lactuca (Chlorophyta was the dominant species. In the upper sandy terrace, no macroorganisms were found. Several species found at Canal Whiteside have a wide circumpolar distribution in Sub-Antarctic regions.

  2. Contaminación de alimentos marinos por cadmio en Lima, 2015

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    Gloria Marín Vallejos

    2015-12-01

    Full Text Available Los objetivos fueron determinar las concentraciones de cadmio en ocho especies de alimentos marinos y comparar con los valores máximos permitidos según la Comisión de la Unión Europea en su Reglamento (CE Nº 1881/2006 y su modificatoria Reglamento (UE N° 488/2014. La investigación fue de carácter descriptivo, trasversal. Las muestras fueron de 100 g de cada ejemplar de pescado en tres oportunidades; los ejemplares fueron: jurel (Trachurus picturatus murphyi, langostinos (Penaeus vannamei, conchas abanico (Argopecten purpuratus, conchas blancas (Semele sp, choros (Aulacomya ater, almejas (Gari solida, machas (Mesonesma donacium y pota (Dosidicus gigas recolectadas al azar en el terminal pesquero de Villa María del Triunfo, provenientes del litoral de la región Lima, sub área 3: Chorrillos – Islas Pachacámac. El proceso de análisis se realizó por espectrofotometría de absorción atómica. Como resultados de los promedios de las concentraciones de cadmio tenemos: en pescados, jurel (Trachurus picturatus murphyi fue 0,35 mg/kg peso fresco; en crustáceos, langostino (Penaeus vannamei fue 0,42 mg/kg peso fresco; en moluscos bivalvos tenemos conchas blancas (Semele sp, conchas abanico (Argopecten purpuratus, choros (Aulacomya ater, machas (Mesonesma donacium y almejas (Gari solida fueron 0,82 – 0,83 – 1,00 – 1,28 y 1,39 mg/kg peso fresco respectivamente. Con este estudio se concluyó que las concentraciones de cadmio en pescados, en moluscos bivalvos y cefalópodos superan los límites permitidos, pero en crustáceos no superan estos límites.

  3. Is there redundancy in bioengineering for molluscan assemblages on the rocky shores of central Chile? ¿Existe redundancia en la bioingeniería de los ensambles de moluscos de las costas rocosas de Chile central?

    Directory of Open Access Journals (Sweden)

    BRENDAN P KELAHER

    2007-06-01

    Full Text Available Bioengineers modify habitats via their own physical structures and substantially increase local diversity in marine ecosystems. On rocky shores, there are large overlaps in the composition of communities associated with bioengineers that form complex mat-like habitats. We investigated the potential for redundancy in habitat provision by these types of habitats by comparing diverse molluscan assemblages associated with Perumytilus purpuratus mussel beds and algal turfs of Corallina officinalis var. chilenis, Gelidium chilense and Gastroclonium cylindricum. At three times between September 2003 and January 2004, we sampled the molluscan assemblages associated with each bioengineer at similar tidal heights on two rocky shores on the coast of central Chile. Of the 31 molluscan species identified, 30 were found in Corallina and 19-22 were identified from the other habitats. The pool of species found associated with each bioengineer overlapped greatly, demonstrating the potential for redundancy in habitat provision and little habitat-specificity. However, multivariate and univariate analyses showed all bioengineers except Gastroclonium contained a unique molluscan assemblage for at least one time of sampling because of variation in frequency of occurrence, richness and total abundance. Recent studies have highlighted many anthropogenic and natural processes that directly influence the diversity and composition of bioengineering species on rocky shores. We demonstrate that the loss of any particular bioengineer would not substantially alter the overall pool of molluscan species on the rocky shores of Chile. The loss of any bioengineer except Gastroclonium would, however, result in decreased local biodiversity because the molluscan assemblages in Perumytilus, Corallina and Gelidium, each contained a significantly different community structure for at least one time of samplingEn los ecosistemas marinos los organismos bioingenieros modifican habitats a

  4. Impacto de "El Niño 1997-98" sobre el asentamiento larval de algunos invertebrados marinos bentónicos de bahía Independencia, Pisco -Perú

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    Elmer Ramos

    2014-06-01

    Full Text Available Se evaluó mensualmente los cambios y la magnitud del impacto de "El Niño" (EN, sobre el mecanismo del asentamiento larval de algunos invertebrados marinos bentónicos, en sustratos artificiales filamentosos (fibra nylon, entre enero 1996 y julio 1998, en una estación fija, a 10m de profundidad, situada en el lado oriental de la Isla Independencia, en Bahía Independencia, Durante 1996, en la fase fría "La Niña" (LN, el número de especies presentó un pico en abril y la densidad en junio. En la fase cálida EN 199798, la densidad total y el número de especies, presentaron un primer pico en marzo de 1997, luego, un segundo pico, en febrero y julio de 1998, respectivamente. Un primer grupo de especies que intensificó su asentamiento durante la fase fría LN 1996, estuvo constituido por el bivalvo Hiatella solida, el turbelario Notoplana sp. y el gastrópodo Caecum chilense. El segundo grupo intensificó su asentamiento en la etapa temprana de la fase cálida EN 1997-98, Y lo formaron el braquiópodo Discinisca lamel/osa, el equinodermo Ophíactís kr6yerí y bivalvos de la Familia Mytllidae, Un tercer grupo, mostró una intensificación del asentamiento larval, en la etapa tardía de la fase cálida EN 1997-98, a inicios de 1998, y fue formado por el bivalvo Argopecten purpuratus y un gastrópodo turriforme. La aparición de larvas recién asentadas de especies tropicales, como el bivalvo Ptería stema y el gastrópodo Epitoníum sp., tuvo lugar en la etapa tardía de la fase cálida EN 1997-98.

  5. Fouling community dominated by Metridium senile (Cnidaria: Anthozoa: Actiniaria in Bahía San Julián (southern Patagonia, Argentina

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    Juan Pablo Martin

    2015-06-01

    Full Text Available The objective of this study is to provide information about a harbour-fouling community dominated by Metridium senile in southern Patagonia. Several steel tubes from the wharf of Puerto San Julián were extracted to perform repair tasks, allowing the attached benthic community to be studied. Sampling was conducted at three levels: lower intertidal, 3-4 m depth and 6-7 m depth. In the lower intertidal, M. senile had a relative abundance of 43%, the most abundant accompanying species being Perumytilus purpuratus, Mytilus edulis platensis and Aulacomya atra atra. At subtidal level, the anemone showed relative abundances of 64% and 65%, and was accompanied by Monocorophium insidiosum at 3-4 m depth and by polychaetes of families Sabellidae and Syllidae at 6-7 m at depth. In the lower intertidal, epibiosis was more frequent on P. purpuratus, A. atra atra and M. edulis platensis, while in the subtidal, the richness of substrate-organisms increased significantly and the anemone was fixed to A. atra atra, M. edulis platensis, Paramolgula gregaria, Crepipatella dilatata, Austromegabalanus psittacus, Hiatella arctica, Polyzoa opuntia, Pyura sp. and Sabellidae tubes. The ability of M. senile to settle on many different organisms, along with other strategies, makes it a colonizer able to displace other species that could compete with it for substratum. Given the cosmopolitan nature of M. senile, the fact that this species has not been previously reported in the coastal zone of the region, and the results of our study, we discuss the possibility that this sea anemone is an invasive alien species in southern Patagonia, or at least a cryptogenic species.

  6. Plasticity and trade-offs in physiological traits of intertidal mussels subjected to freshwater-induced environmental variation

    KAUST Repository

    Ramajo, L

    2016-05-17

    Environmental gradients play an important role in shaping geographic variability in coastal marine populations. Thus, the ability of organisms to cope with these changes will depend on their potential to acclimatize, or adapt, to these new environmental conditions. We investigated the spatial variability in biological responses shown by Perumytilus purpuratus mussels collected from 2 intertidal areas experiencing contrasting freshwater input influences (river-influenced vs. marine conditions). To highlight the role of plasticity and adaptive potential in biological responses, we performed a reciprocal-Transplant experiment and measured relevant phenotypic traits including mortality, growth, calcification, metabolism, and chemical composition of the shell periostra-cum. We determined that mussels exposed to river-influenced conditions had increased metabolic rates and reduced growth rates, as compared to mussels experiencing marine conditions (p > 0.05). While the energy investment strategies of the 2 local populations resulted in similar net calcification rates, these rates decreased significantly when mussels were transplanted to the river-influenced site. Stressful conditions at the river-influenced site were evidenced by decreased survivorship across treatments. Freshwater inputs modify the organic composition of the shell periostracum through a significant reduction in polysaccharides. Although our field experiment did not identify specific environmental factors underlying these contrasting phenotypic changes, the results imply that plasticity plays a strong role when P. purpuratus is exposed to some combination of natural (e.g. salinity) and anthropogenic influences (e.g. pollution), and that the lack of exposure to freshwater may promote less tolerant mussels with greater potential for local adaptation. © The authors 2016.

  7. Efecto del detergente biodegradable (aquil sulfonato de sodio en el consumo de oxígeno y tasa de filtración del bivalvo Semimytilus algosus

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    Guillermo Alvarez

    2014-06-01

    Full Text Available El consumo de oxigeno específico (COE e individual (COI de Semimytilus algosus (0,0856 a 0,1869 g fue determinado en respirómetros cerrados estáticos (300 ml aprox. en presencia de 3 concentraciones de detergente (CO = 0,00; C1 = 0,02; C2 = 0,04; y C3 = 0,06 mg I-1 de detergente. Para detectar el oxigeno disuelto se usó el método de Winkler. La tasa de Filtración individual (TFI fue calculada en ausencia de detergente por consumo de la diatomea Chaetoceros gracilis con los mismos individuos expuestos al detergente durante los experimentos de respiración. Las condiciones de experimentación fueron 35 % de salinidad y 17 ± 0,5ºC. Los resultados observados indican que el detergente aún siendo biodegradable, a tiempos; cortos de exposición altera la tasa respiratoria e incrementa el consumo de oxigeno y velocidad de la tasa de filtración a medida que la concentración de detergente se incrementa.

  8. Definición estratégica y viabilidad económica de un vivero para moluscos bivalvos en el delta del Ebro

    OpenAIRE

    Parisi Sarobé, Jaume

    2011-01-01

    Moluscos Deltamar empezó su actividad exclusivamente con el engorde de mejillón. En 1999 amplía su actividad al engorde de ostrón a partir de semilla de un tamaño de 10 - 15 mm. En 2008 inicia la fase de pre-engorde de ostrón (4-5 mm) y engorde de almeja. Ahora pretende dar otro salto cualitativo en las primeras fases del cultivo de la semilla de almeja y ostrón reduciendo su tamaño de entrada e iniciarse en el engorde de la ostra plana (Ostrea edulis). El proyecto incide en...

  9. Effect of marine contamination on the genetic population structure of the bivalve Crassostrea angulata; Efecto de la contaminacion marina sobre la estructura genetica poblacional del bivalvo Crassostrea angulata

    Energy Technology Data Exchange (ETDEWEB)

    Cross, Ismael; Rebordinos, Laureana [Laboratorio de Genetica, Facultad de Ciencias del Mar, Universidad de Cadiz, Cadiz (Spain)

    2003-06-15

    Seven enzyme loci were analyzed in three natural populations of Crassostrea angulata located on the southern Atlantic coast of the Iberian Peninsula. Two of the populations showed distinct levels of contamination by heavy metals, whereas the third was not contaminated and served as control. These seven loci were shown to be very variable in terms of the number of alleles, polymorphism and average heterozygosity. The Lap and Mdh1 loci presented null alleles. A significant positive correlation was found between the number of alleles and the concentration of iron that was fitted to a model of linear regression. However, this correlation was negative for the heterozygosity, and significant for cadmium and zinc. The Em, Lap, Mdh1 y Xdh loci showed a deficit of heterozygotes in all the populations. The values of heterozygotic deficit (D) were statistically significant between the contaminated populations and the control for Mdh1 and very close to a significant level for Em. In Pgm, a heterozygotic excess appeared in the control population and deficit, which was correlated to the increased levels of metal concentration, occurred in the other two populations. The differences between the D values of the three populations were also significant in this locus. Positive, negative and significant relationships were obtained between the concentration of metals and some alleles of the Em, Lap and Pgm loci. Also, the homozygotic genotypes of the alleles with positive correlation values were selected in the contaminated areas, while the heterozygotes were more favoured in the control population, showing an adaptive behavior and corroborating the utility of some of these loci as biomarkers in studies of population dynamics in areas subjected to environmental contamination. [Spanish] Se analizaron siete loci alozimicos en tres poblaciones naturales de Crassostrea angulata localizadas en la costa suratlantica de la Peninsula Iberica. Dos de las poblaciones mostraban distintos niveles de contaminacion por metales pesados, mientras que la otra no estaba contaminada y se utilizo como control. Los siete loci se mostraron muy variables en cuanto a numero de alelos, nivel de polimorfismo y heterocigosidad media. Los Loci Lap y Mdh1 presentaron alelos nulos. Para el hierro se encontro una correlacion positiva significativa entre el numero de alelos y la concentracion que se ajustaba a un modelo de regresion lineal; sin embargo, esta correlacion fue negativa para la heterocigosidad, y significativa para el cadmio y el zinc. Los loci Em, Lap, Mdh1 y Xdh mostraron deficits de heterocigotos en todas las poblaciones. Los valores de deficit de heterocigotos (D) fueron estadisticamente significativos entre las poblaciones contaminadas y el control para el locus Mdh1 y muy proximos al nivel de significacion para el Em. En el locus Pgm aparecio un exceso de heterocigotos en la poblacion control y un deficit, correlacionado con el aumento de niveles de concentracion de metales, en los otros dos. Las diferencias entre los valores de D de las tres poblaciones tambien fueron significativas para este locus. Se obtuvieron relaciones significativas, positivas y negativas entre la concentracion de metales y algunos alelos de los loci Em, Lap y Pgm. Ademas, los genotipos homocigotos de los alelos con valores de correlacion positivos fueron seleccionados en las zonas mas contaminadas, mientras los heterocigotos eran los mas favorecidos en la poblacion control, mostrando un comportamiento adaptativo y corroborando la utilidad de algunos de estos loci como biomarcadores en estudio de dinamica de poblaciones en zonas sometidas a contaminacion ambiental.

  10. Consumption and digestion of animal food by rocky intertidal herbivores: an evaluation of digestive flexibility and omnivory in three grazing species Consumo y digestión de alimento animal por herbívoros del intermareal rocoso: evaluación de flexibilidad digestiva y omnivoría en tres especies de pastoreadores

    Directory of Open Access Journals (Sweden)

    Patricio A Camus

    2009-01-01

    Full Text Available The ingestion of invertebrates by herbivores on rocky intertidal shores is traditionally considered a casual phenomenon. However, a recent study of 29 species in northern Chile shows that animal consumption is widespread, consistent, and important, suggesting that some of these herbivores may actually be omnivores. Therefore, we examined the capability of three common Chilean herbivores (the key-hole limpets Fissurella limbata and Fissurella pida and the polyplacophoran Chiton granosus to digest animal food. For each species, we conducted no-choice feeding experiments using artificial foods based on either algal or animal tissue from one of their frequent prey (Ulva rigida, Perumytilus purpuratus. After the feeding trials, we evaluated the total proteolytic activity (availability of free amino acids in the digestive contents of the species studied and, as a reference, we evaluated this activity in animals obtained directly from the field. We found that all three species were able to eat animal food, and this consumption was not significantly different from that of algal food, suggesting that both foods were not only edible but at least similarly palatable. In addition, we detected comparable levels of proteolytic activity under the three feeding conditions for the three species. No statistical differences were found for C. granosus, but activity was significantly higher with animal food in F. limbata and with algal food in F. pida. Our data show the high digestive flexibility of these species, suggesting their ability for adaptive modulation and the possibility that they are true omnivorous consumers. We discuss the implications of these results for our current view of the structure of rocky intertidal food webs.La ingestión de invertebrados por herbívoros de costas intermareales rocosas se considera tradi-cionalmente un fenómeno casual. Sin embargo, un estudio reciente en 29 especies del norte de Chile muestra que el consumo animal es

  11. Butyltin compounds and their relation with organic matter in marine sediments from San Vicente Bay-Chile.

    Science.gov (United States)

    Pinochet, Hugo; Tessini, Catherine; Bravo, Manuel; Quiroz, Waldo; De Gregori, Ida

    2009-08-01

    Tributyltin and its degradation products, mono-and dibutyltin have been determined in sediments collected in some representative sites in San Vicente Bay, Chile. The organic matter contents of sediments and water collected simultaneously from the same sampling sites were also determined. High levels of total organic carbon were found in sediments, especially in those from the northern part of the bay (1.80-8.87%). Good correlations were found between total organic carbon and the oxidizable and refractory carbon fractions. Among the butyltin species determined, TBT presented the highest levels, ranging from 14 to 1,560 ng Sn g(-1) dry weight. Concentration ratios of TBT to DBT ranged between 1.33 and 3.10, showing a high degree of contamination in sediments of this Chilean bay. All data obtained were analysed by the chemometric method of principal components analysis. A strong correlation was found between TBT and DBT concentrations in sediments, the different organic matter contents in sediments and water. In marine organisms only TBT was detected, containing the filterer organism Semele solida higher level than Perumytilus purpuratus and Pyura chilensis (220, 150 and 120 ng Sn g(-1) dry weight, respectively). For the alga Rodoficea iridae the TBT concentration was 60 ng Sn g(-1) dw. Comparatively, these values are higher than those reported for the same kind of marine organisms worldwide. The different samples from San Vicente Bay were found to be contaminated by TBT. This contamination can be attributed to the different anthropogenic activities taking place in the bay.

  12. Gene : CBRC-PHAM-01-1001 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available ical protein, partial [Strongylocentrotus purpuratus] 3e-79 50% MHACIHPSTFPSTHSPIHPPPIHSSIHPPTHLSTHPSTHFPIHASTHPSTHQPASYPFIYLPIHPSTH...PSTHSPIHASTHPSTHQPTSQPAIHLSTHPSIHPSIHPPTHSPTHPPTHPSIHPSMHPPIRPPTSQPASQPFIYLPIHPSTH...PSTHPPIHPFIHPPIHPCIHPSIHPLIHQSIHPSIHPSTHPLTHSFTHSPIHPSTQPSIYPSTHSFIHSPTHPSIDPSTHPFI

  13. Gene : CBRC-CJAC-01-0267 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available ein [Strongylocentrotus purpuratus] 6e-23 26% MRHRDAAGDRRHKLQPGAGRAIGQSACVGPGPSTTPHADSPILLCPSTTPHADCPILLRLSTTPNADCPILLLCPSTTPHADCP...ILLYPSNTPHADCPILLCPSTTPNADCPILLCPSTTPHADCPILLCPSTTPHADCPILFLCPSTTPHADCPSLLYPSNTPHADC...PILLCPSTTPSADCPILLCPSTTPHGDCPILCPSTTPHADCPILLCPCTTPHADCPILLCPSTTSHADCPVLLCPSTXXXXXX

  14. Ecotoxicidad de metales en el bivalvo dulceacuícola Anodontites trapesialis y su potencial uso en el biomonitoreo de ambientes acuáticos en la Amazonía peruana

    NARCIS (Netherlands)

    Loayza-Muro, R.; Elías-Letts, R.; Herkovits, J.

    2009-01-01

    The effects of Cd, Cu and Zn on the filtration rate of Anodontites trapesialis were tested in order to evaluate the suitability of this freshwater mussel for ecotoxicity bioassays. This sublethal endpoint is very relevant due to the ecological role of this mussel in Amazonian environments. The

  15. Ausencia de detección de enterovirus en bivalvos Anadara tuberculosa (Bivalvia: Arcidae) por contaminación química en el Pacífico de Costa Rica

    OpenAIRE

    Libia Herrero U.; Alejandro Palacios F.; Laya Hun O.; Francisco Vega A.

    1999-01-01

    Anadara tuberculosa es uno de los moluscos más abundantes de importancia comercial en Costa Rica. Su hábitat acuático es una fuente potencial de contaminación fecal y química para el ser humano. El objetivo de este trabajo fue determinar enterovirus, especialmente poliovirus y el virus de la hepatitis A y contaminación química como nitratos y sulfatos en las carnes y los líquidos internos. Se recogieron trece muestras de cuatro sitios del golfo de Nicoya, de tres sitios del manglar Sierpe-Tér...

  16. Ausencia de detección de enterovirus en bivalvos Anadara tuberculosa (Bivalvia: Arcidae por contaminación química en el Pacífico de Costa Rica

    Directory of Open Access Journals (Sweden)

    Libia Herrero U.

    1999-09-01

    Full Text Available Anadara tuberculosa es uno de los moluscos más abundantes de importancia comercial en Costa Rica. Su hábitat acuático es una fuente potencial de contaminación fecal y química para el ser humano. El objetivo de este trabajo fue determinar enterovirus, especialmente poliovirus y el virus de la hepatitis A y contaminación química como nitratos y sulfatos en las carnes y los líquidos internos. Se recogieron trece muestras de cuatro sitios del golfo de Nicoya, de tres sitios del manglar Sierpe-Térraba (pacífico de Costa Rica y de cinco pescaderías de San José, la capital de Costa Rica. Las muestras fueron ensayadas por 1 coliformes fecales (Número Más Probable/100 ml, 2 aislamiento de enterovirus en cultivos celulares (Hep-2 y FrhK-4, 3 citotoxicidad en células Vero y 4 la habilidad de las muestras de inactivar 10 DI50% de poliovirus en cultivos celulares. El Número Más Probable/100 ml de las aguas fue más alto de lo que se considera adecuado para el uso recreacional, aunque los coliformes en los líquidos y las carnes fue en general mucho más bajo. No se logró el aislamiento de ningún agente citopatogénico, pero encontramos que la concentración de nitratos y sulfatos de las muestras fue mayor a lo aceptable para consumo humano. La toxicidad intrínseca de las muestras en cultivos celulares fue de una dilución de 1/8 aunque algunas muestras mostraron toxicidad a una dilución de 1/128. Los líquidos fueron más tóxicos que las carnes pero no se encontró una correlación entre la toxicidad en cultivos celulares y la toxicidad química: aparentemente otros contaminantes no identificados en este trabajo fueron los responsables. Se analizó la habilidad de los líquidos y las carnes de inactivar 10 DI50% de poliovirus demostrando que los líquidos y las carnes con más toxicidad en cultivos celulares fueron los que mostraron un porcentaje mayor de inactivación del poliovirus. Se recomienda la vigilancia de la contaminación química de estas aguas.Anadara tuberculosa is one of the most abundant mollusks of commercial importance in Costa Rica. Its habitat water is a potential source of fecal and chemical contamination to humans. We wanted to asses enterovirus, mainly poliovirus and hepatitis A virus and chemicals such as sulphates and nitrates in meat and body fluids. Thirteen samples were taken from four sites in Nicoya Gulf, three sites in the Sierpe-Térraba mangrove (Pacific of Costa Rica and from five fish markets in San José, the capital of Costa Rica. Samples were tested for 1 fecal coliforms (Most Probable Number/100 ml, 2 isolation of enterovirus in cell culture (Hep-2, FrhK-4, 3 cell cytotoxicity in Vero cells and 4 the ability to inactivate 10 ID50% of poliovirus in cell culture. The Most Probable Number/100 ml in surrounding water was higher than the accepted standard for recreational waters, although the number of fecal coliforms in meats and body fluids was lower than in the external water. No cytopathogenic agents were isolated, but we found nitrate and sulphate concentrations that exceeded maxima for human consumption and recreation. The intrinsic cytotoxicity of the samples was at a 1/8 dilution, but some samples were cytotoxic at dilutions of 1/128. Body fluids were more cytotoxic than meats, but a positive correlation between cytotoxicity and chemical contamination was not determined: apparently other pollutants not identified in this study were responsible. Fluid and meat capacity to inactivate 10 ID50% of poliovirus in cell culture was demonstrated. Samples that were toxic for cell cultures also showed a higher percentage of poliovirus inactivation. Monitoring chemical pollution in these waters is highly recommended.

  17. Caracterización del antígeno reconocido por el anticuerpo monoclonal M22.8 y su posible implicación en la biomineralización de bivalvos

    OpenAIRE

    Calvo Iglesias, Juan

    2017-01-01

    En el laboratorio de Inmunología de la Universidad de Vigo se obtuvieron anticuerpos monoclonales dirigidos específicamente frente a larvas de mejillón. Desde su obtención, se han optimizado los métodos de detección específica de dichas larvas, y se vienen empleando de forma rutinaria por parte de la Fundación Cetmar desde finales de 2008 en el muestreo semanal que se realiza para conocer la distribución espacio-temporal de larvas. Uno de los anticuerpos, el M22.8 se ha demostrado que...

  18. Gene : CBRC-PHAM-01-1775 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available ical protein, partial [Strongylocentrotus purpuratus] 4e-96 53% MTHPSIHLPTHLSMHPSTHPLIHPSTHPSIHPSTHPSTHPSTHPSIHPPTHPPIHPSTH...PPIHPPIHPSIHPPIHPSIHPPTHPSIHPSTHPPIHPSTYLSIHPSTHPSTHPSIHPPTHPPIHPSTH...PPIHPPIHPSIIHYLXXXXXXXXXXXXXXXXXHPPIHPSIHPPTHPSIHPSIHPSIHPSTHPSTHPSIHPPTHPSIHPSTHPPIHPSTYLSIHPSTHPSTHPSIHP...PTHPSIHLPTHPFIHPSIHPPTHPLIHSSIHISTHPSIHPSIHPSIHPPIHPSTHPPIHPSTYPSTHSSIHPPTYPPIHPCIINPPTYPSMHVPIDPPIHPSIRPLIHPSIHPSIHPSTH

  19. Gene : CBRC-PHAM-01-1697 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available ical protein, partial [Strongylocentrotus purpuratus] 1e-83 51% MLGLEIETHPSTHSSIHPSIHPPIHPSTHPPIHPSTHPSIHPPSIHPPIHPSIHPSTRPPIHPSTH...PPIHPPTHPSIHPPTHPSTHPPIHPSTHPPIHPPTHPSIHLPIHQSTHPSIHPSTHPSSHPTTHPSTH...PSIHPSIHPSIHPTIHPLIHSSIHLSIHPSVHPSIHPSIHLPTHLSTHPPTHPSIHPSTDLSTYPSSINPPIYPPIHLSIHLSIHPFIYPFIYISIHSPIHPFTHPSTHLPTHPSTHPSSHPFINPSIHHPTLPPIHPSIHPSTHLCIHPPIHPSSHQSFTEKLLCIRQHFRN ...

  20. Gene : CBRC-PHAM-01-1058 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available cal protein, partial [Strongylocentrotus purpuratus] 4e-82 50% MYLGGSYPTTAPFSHWSSSGRGRAPWLMPLCARLLKEVTEPAAPLSHSSTH...PLTPPTPXXXXXXXXXXXXXXXXXLIHSSTQPIHLPTFPLNHSSTHPLFPSTHSSTHPPIHSSTHPPTHSSTHPP...NHLPTYPPIHSPTHPLTHSLIHSPTQSLIHPPTHPLVHLPAHPPTPLIHSPTHPLIHPPTHPLNHPSTYPPILLPTYPLTYPPTHPPTHSSTHPPRHSSTHPPSHSSTH...PLIHLSAYLLIHPPHSFTHPPTHSSTHPPTHPSIQPHTYLSTHPLIHLPTYLLIHSPTQPPVHLPTHPLTHPSTHPLTHPATHPPTHPSTCPPTCSSTHPAHPLTHPPTHPSTQPPTHLSTH...PPTHLSPHLPTHSSTHPLIHSPTHPLIHLSTHPLIHTPTYPLVHLPAHPLTHPSTCPPTYSFTHPP

  1. Gene : CBRC-PHAM-01-1822 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available cal protein, partial [Strongylocentrotus purpuratus] 7e-69 47% MHSSTHSCIHPPVHPFIHPSIHPSIHPSIHPSIHPSIHPSTHTSTYPPIHPSTHPLIHLPIHLSTH...PHIHSPARLPTHPLTHSSTHSSTHSCIYLSTYPPAHPSTHSSIHPSIQPVIHLPIHLSTHPPTYPFTHPSVYASTH...PFIYPFINPFMHPSIHPLTHPPTHPSTHLSIHSSIHPSTHPLIHLPIHSSIHPSIHPSIHPSIYPSTHPLIHLPIHPPNHPSIHPPIYLPIHSPIHPPIHASIHASIHPSTHPPTHPSIHSQNQPHSPTQSVEEPSVSLGKGETYPVSQHSSNL ...

  2. Gene : CBRC-PHAM-01-0393 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available ical protein, partial [Strongylocentrotus purpuratus] 7e-71 47% MYPSIHSSSTHPFIQHPSTHTPIHPSIHPSTHPSTHPSTHLSIY...PTIHPPIHIPIHPVIQLSIHPPTHSSIYPHTHPSTYSSAHPSPSIDPPSICPSIYPSTHPSIHPSMHPSTHPQTHPSTHPFIHLPIHPSTHPSICPSTH...PPTHPSIHPSIRLPIHPPTHPFTHPSTYSSAHQSIHPRAHLAIHPSTHPSTHPSIYPCIHPLFTPHHPSTHPSIHLPVHSPSHPTTHPLIHLPIHPSTH...LPIHLSIHPSIRLPTHPPIHTYTHLSIHSCTVHPSVHPSIPPSLSPSLPPSPNHPSTHTHSPTSHHCRVPGPLLSTPSGPGRELL ...

  3. Gene : CBRC-TTRU-01-0415 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available TED: hypothetical protein [Strongylocentrotus purpuratus] 2e-59 34% MRSCMSPLHKHTMNHPLGHLCRLNETMHVEQLASIIHPPSIHPSSTYLPVIHPSTH...HPSIHPSSTYLPIIHLSTHHPSIHPSSTYPPIIHPSTHHPSIHPSSTYPPIIHLSTRHPSIHPSSIHPPIIHLSTHHPPIHPSSTYLLVIHPSTH...HPPIYPSSTYPPIIHLSTRHPSIHPSSTYPPIIHLSTHHPPIHPSSTYPPSSIHPPIIHLSTHHPSIHPSSTYPPIIHPSTH...HPPIHPSSTYPPIIHLSTRHPSIHPSSIHPLIIHLSTHHPPIYPSSTYPPIIHLSTHHPSIHPSSIYPPIIPPIYPSTIHSTPSSXXXPIIHLSTHHPPIHPSSTYPPIIHLSTH...HPPIHHHPSIHPSSTYPPIIHPSTHHPPIHPSSIHPPIIHLSTHHPPIHPSSTYPPVIHPSTHHPSIHSSSTYPPIIHLSTHHPPILPSSIYPLIIHPSTHHPSIHPSSTYLPIHHPSTH

  4. Gene : CBRC-PHAM-01-0998 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available cal protein, partial [Strongylocentrotus purpuratus] 1e-90 51% MHPPTHPSIHPSTHPSTHPPIYPPIHPPIHPSTHPPTHRTIHPPIEPSIHPPTHLSTHPSTHPSIYPSTH...PSIHPSTHPSTHPPIYLPIHPPIHPSIHPSTHPPTHRTIHPPIEPSTHPLNHPPTH...PSIHPSIHLSIHPPIHPSIHSSIHPSIHPSTHRTIHPPIEPSTHPPIEPSTXXXXXXXXXXXXXXXXXPSIHLSIHPPIHPSIHSSIHPSIHPSIHPSTHPSIHPPIHPSTHPSNHPPIHPSIHPSTHPSTH...PPIYPPVHPPIHPSIHPSTHPSNHPPTHPPIHPPIEPSTHPSNHPSTHPPIYPPIPPPIHPSIHPPTHPSIHPFIHPPIHPSIHSSIHPSIHPSTHPPIHPPIEPSTH...PSIHPSIHSSIHPPTHLSTRPSTHPSIHPPIHPPIEPSTHPSNHPPTHPSIHPPTHP

  5. Gene : CBRC-TTRU-01-1225 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available ical protein, partial [Strongylocentrotus purpuratus] 8e-97 55% MCREKTHPPTYPSIHPPIHPLIHPSIHPSIHPPIHSPIHPSTHPSNHPSTH...PPNHSSIHSCIHPSIHPFTHPNTHPSTHPSVHPPIHPLIHPSIHPSTNSSSHPSTHPSTHPSTHSLIHPSIHPCFHPSTHPSTHPSIHPSTH...PSIHPPTHPSIHPPTHPSTHSSTHPPIHPSTLPSIHSFIHPSIHPPTHPATHPLIHPPTHPPIHPSTHPSIHASTHPPTHPPIHPPIHPP...IHPSIHPPIHPSIHPPIHPSIHPSIHPSIHPPIHPSIHPPTHPSIHPSTHPSTHPSIHHPSSHPTTHPPTHPSIHSPIHPPKHPHIHPPIHTSICPFEYLTVLVTHKDV ...

  6. Gene : CBRC-PHAM-01-1379 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available ical protein, partial [Strongylocentrotus purpuratus] 2e-82 52% MHPFIFSGPEATPSFLPPIHPSTHPSTHPPIHPSTHPSIHPPIH...PPIHPPIHPFTHPLTHPSIHPFTHPLIHPSIHPSTQPLTHPSIHPSTHSSTHPLIHQSIHPFTHPLTHPSIHPPIHSPIHPSTHPPIHPPIHSSTHPSTH...SPIHSSIHPSTHSSTHPLIHPSIHPFTHPLIHPPIHPFIHPSTHPPIHPPIHPFTHPLTHPLIHPFTHPLTHPSIHPFTHPLIHPSIHP...FTHPLIHPSIHPFTHPLXXXXXXXXXXXXXXXXXPPIHPFIHPSTHPPIHPPIHPSTHPSIHPPIRLTFSPFISVLEAVSGSRGPHGASFCHRGPRIWGDRIKHDMRGSQWFRAHLGLSCLRARSLALRRVDRGS ...

  7. Gene : CBRC-GGOR-01-1310 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available ical protein, partial [Strongylocentrotus purpuratus] 1e-47 38% MVSVNTSSVTSVSTPSVSTPSVTSLSTPSVTSLSTPSVTSLSTLSVSSLSTPSVTSVSTPSLSTPSVT...SLSTPSVTSLGTPSVTSLGTPSVTSVSIPSVTSLSTLSVSPLSTPSVTSLSTPSVTSVSTPSLSTPSVTSLGTPSVT...SVGTPSVTSVSTPSLSTPSVTSLSTPSVTSVSTPSVTSLSTPSVSSLSTPSVTSLSTPSITSLSTPSVTTPSVPSVSTPSVTSLSTLSVSSLSTPSVT...SVGTPSVSTPSVPSVSTPSVTSLSIPSLSTPSVTSLSTPSVTSVHHHSVHHQSHHSVHHQSHHSVHHQSHHSVHHQSHHSVHHQSHQYTITQYTISHITRYTISLTTQYTISHITRYTISHITQYTISHISQYTISHITQ ...

  8. Efectos económicos de la estrategia de cosechas múltiples en el cultivo del ostión del norte Argopecten purpuratus: una oportunidad para mejorar la competitividad

    Directory of Open Access Journals (Sweden)

    Eduardo P Pérez

    2014-03-01

    Full Text Available Una situación recurrente en el mercado de muchas especies bajo cultivo acuícola es la tendencia en la disminución del precio internacional en oposición al aumento en los costos de los insumos, lo que obliga a la industria a ser innovadora al momento de rentabilizar la inversión. Una opción poco explorada es el aumento del valor de la producción a través de una cuidadosa selección de tamaños y tiempos de cosechas. Las cosechas parciales permiten que calibres subóptimos puedan tener el tiempo necesario de crecimiento hasta alcanzar mejores atributos, al mismo tiempo que la fracción de mejor crecimiento es cosechada y puesta disponible en el mercado. Difiere significativamente de la estrategia alternativa de cosechas totales, donde la totalidad de la producción es cosechada al mismo tiempo. Así, el óptimo económico será resultado del tiempo de primera cosecha (DPC, de la longitud de cosecha (LC, número de cosechas (NC e intervalo de tiempo (Δt entre cosechas sucesivas. Mediante un modelo de simulación, alimentado con valores reales de una empresa de cultivo de ostión del norte (Argopectenpurpuratus se analizó el resultado económico de la estrategia de cosechas múltiples. Los resultados indican que las combinaciones alternativas de DPC, LC, Δt y NC generan distintos niveles de rendimientos económicos, aspecto que debiera ser considerado por los productores. En los escenarios simulados de cosechas, una decisión incorrecta en este sentido podría generar una diferencia del orden de US$ 510.000.

  9. Informe final. Proyecto FIP N° 2006-36 (2a. licitación) Programación y análisis de información biológica y oceanográfica obtenida a través del programa de sanidad de moluscos bivalvos (PSMB).

    OpenAIRE

    Murillo Haro, V.; Figueroa Fabrega, Luis; Paredes Iturrieta, N.; González Maier, R.; Oyarzún Vera, M.; Espinoza Alvarado, C.; González Van de Pierre, M.; Sánchez Valenzuela, L.; Guzmán Méndez, F.

    2008-01-01

    La investigación tuvo como objetivo recopilar, analizar y correlacionar los parámetros y variables provenientes de los registros de la aplicación del PSMB, así como de otras fuentes de información, con el fin de conocer la evolución de los eventos de Floraciones de Algas Nocivas y poder identificarlas y proponer macrozonas que se caractericen por la ocurrencia de determinados FANs o plagas hidrobiológicas.

  10. NCBI nr-aa BLAST: CBRC-DNOV-01-0174 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DNOV-01-0174 ref|XP_786035.2| PREDICTED: similar to autism-related protein 1 [...Strongylocentrotus purpuratus] ref|XP_001191209.1| PREDICTED: similar to autism-related protein 1 [Strongylocentrotus purpuratus] XP_786035.2 2.3 34% ...

  11. NCBI nr-aa BLAST: CBRC-DDIS-04-0105 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DDIS-04-0105 ref|XP_795306.2| PREDICTED: similar to mind bomb [Strongylocentro...tus purpuratus] ref|XP_001195978.1| PREDICTED: similar to mind bomb [Strongylocentrotus purpuratus] XP_795306.2 0.003 64% ...

  12. NCBI nr-aa BLAST: CBRC-CBRE-01-1093 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CBRE-01-1093 ref|XP_783390.1| PREDICTED: similar to tachykinin receptor [Stron...gylocentrotus purpuratus] ref|XP_001192442.1| PREDICTED: similar to tachykinin receptor [Strongylocentrotus purpuratus] XP_783390.1 6e-47 31% ...

  13. NCBI nr-aa BLAST: CBRC-CELE-04-0101 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CELE-04-0101 ref|XP_783390.1| PREDICTED: similar to tachykinin receptor [Stron...gylocentrotus purpuratus] ref|XP_001192442.1| PREDICTED: similar to tachykinin receptor [Strongylocentrotus purpuratus] XP_783390.1 1e-45 34% ...

  14. NCBI nr-aa BLAST: CBRC-CREM-01-1164 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CREM-01-1164 ref|XP_783390.1| PREDICTED: similar to tachykinin receptor [Stron...gylocentrotus purpuratus] ref|XP_001192442.1| PREDICTED: similar to tachykinin receptor [Strongylocentrotus purpuratus] XP_783390.1 3e-45 34% ...

  15. NCBI nr-aa BLAST: CBRC-CBRE-01-0130 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CBRE-01-0130 ref|XP_782524.1| PREDICTED: similar to Slc40a1-prov protein [Stro...ngylocentrotus purpuratus] ref|XP_001190795.1| PREDICTED: similar to Slc40a1-prov protein [Strongylocentrotus purpuratus] XP_782524.1 4e-26 30% ...

  16. NCBI nr-aa BLAST: CBRC-GGOR-01-1262 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-GGOR-01-1262 ref|XP_781825.2| PREDICTED: similar to spicule matrix protein SM29... [Strongylocentrotus purpuratus] ref|XP_001189992.1| PREDICTED: similar to spicule matrix protein SM29 [Strongylocentrotus purpuratus] XP_781825.2 3e-36 29% ...

  17. Dicty_cDB: Contig-U01139-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 179314 ) Strongylocentrotus purpuratus clone R3-1102P16, W... 32 6.6 5 ( FG289388 ) 1108793297216 New World ...Screwworm Egg 9261 ESTs C... 38 6.9 2 ( FG286433 ) 1108770714983 New World Screww

  18. Centrocestus formosanus (Opisthorchiida: Heterophyidae) como causa de muerte de alevines de tilapia gris Oreochromis niloticus (Perciforme: Cichlidae) en el Pacífico seco de Costa Rica

    OpenAIRE

    Arguedas Cortés, Donald; Dolz, Gaby; J. Romero Zúñiga, Juan; E. Jiménez Rocha, Ana; León Alán, Dennis

    2009-01-01

    Centrocestus formosanus es un parásito trematodo zoonótico originario de Asia asociado con muertes de peces principalmente de cultivo. 907 moluscos provenientes de estanques sembrados con tilapias, seleccionados uno por provincia fueron identificados al nivel taxonómico especifico. Se identificaron cuatro gastrópodos y un bivalvo: M. tuberculata, M. turricula, P. flagellata, H. cubensis y A. luteola. Se reporta, por primera vez, la presencia de dos especies de moluscos en Costa Rica. Se ident...

  19. Notes on Plectranthus (Lamiaceae from southern Africa

    Directory of Open Access Journals (Sweden)

    E. J. van Jaarsveld

    1997-10-01

    Full Text Available Four new Plectranthus taxa from South Africa are described: P. malvinus Van Jaarsv. & TJ.Edwards, P. saccatus subsp. pondoensis Van Jaarsv. & S.Milstein,  P. purpuratus subsp. tongaensis Van Jaarsv. & TJ.Edwards and  P. purpuratus subsp. montanus Van Jaarsv. & TJ.Edwards.  P. aliciae (Codd Van Jaarsv. & TJ.Edwards and  P. lucidus (Benth. Van Jaarsv. & TJ.Edwards are given new status, and P. pentheri (Giirke Van Jaarsv. & TJ.Edwards is transferred to this genus from Coleus and recognized as a species.

  20. Dicty_cDB: Contig-U15761-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available FC852030 ) CBHN7140.fwd CBHN Metridium senile tentacle Metri... 38 0.027 4 ( AM436240 ) Vitis vinifera cont...fwd CBHN Metridium senile tentacle Metri... 36 0.15 4 ( AM562664 ) Paracentrotus lividus EST, clone MPMGp117...Repeat Enriched Librar... 42 0.47 2 ( FC852433 ) CBHN7354.fwd CBHN Metridium senile tentacle...622.fwd CBHN Metridium senile tentacle Metri... 48 0.50 2 ( AC177745 ) Strongylocentrotus purpuratus clone R...77102 ) Strongylocentrotus purpuratus clone R3-4012O12, W... 44 1.8 9 ( FC853499 ) CBHN7939.fwd CBHN Metridium senile tentacle

  1. Domain combination of the vertebrate-like TLR gene family ...

    Indian Academy of Sciences (India)

    similar to Oncorhynchus mykiss TLRs. 74180 similar to Takifugu rubripes TLR9. 102021 similar to Strongylocentrotus purpuratus TLR3 precursor. Table 2. Database accession numbers of V-TLRs, V-TIRs, V-LRRs and P-Tolls used for phylogenetic analysis. The accession numbers of. NCBI are listed. Branchiostoma floridae ...

  2. EST Table: FS927325 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available ar to Restin (Reed-Steinberg cell-expressed intermediate filament-associated protein) [Strongylocentrotus pu...rpuratus] ref|XP_001183478.1| PREDICTED: similar to Restin (Reed-Steinberg cell-expressed intermediate filam...CTED: similar to restin (Reed-Steinberg cell-expressed intermediate filament-associated protein) [Tribolium castaneum] CK533543 fwgP ...

  3. Classification and expression analyses of homeobox genes from ...

    Indian Academy of Sciences (India)

    2015-04-27

    Apr 27, 2015 ... neoformans; Ec: Encephalitozoon cuniculi; Nv: Nematostella vectensis; Cs: Cupiennius salei; Sp: Strongylocentrotus purpuratus; Mda: Myotis davidii; Aa: Aedes aegypti; Ta: Trichoplax adhaerens; Sk: Saccoglossus kowalevskii; Cgi: Crassostrea gigas; Dr: Danio rerio; Rn: Rattus norvegicus; Cg: Cricetulus ...

  4. Dicty_cDB: Contig-U13388-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 26 10 ( CP000768 ) Campylobacter jejuni subsp. doylei 269.97, comple... 32 0.35 2... 0.41 4 ( AC201457 ) Strongylocentrotus purpuratus clone R3-3037H20, W... 40 0.47 2 ( AY816330 ) Campylobacter jejuni subsp. doyle

  5. Fulltext PDF

    Indian Academy of Sciences (India)

    Quililongo C. J., Rıos-Ramırez M. A., Velásquez-Cumplido L., Morales-Mun˜oz B. and Escobar-Fica J. A. 2012 Development and characterization of ten polymorphic microsatellites isolated from the scallop Argopecten purpuratus. J. Genet.

  6. Dicty_cDB: CHK163 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ylocentrotus purpuratus genomic clone Plate=74 Col=16 Row=D, DNA sequence. 44 9e-12 6 BW529286 |BW529286.1 Ciona savigny...i cDNA, clone:cslv010m05, 5'end, single read. 48 1e-10 6 BW559326 |BW559326.1 Ciona savigny

  7. Hábitos alimenticios de Sphoeroides testudineus (Perciformes: Tetraodontidae en el sistema lagunar de Ría Lagartos, Yucatán, México

    Directory of Open Access Journals (Sweden)

    Ariel Adriano Chi-Espínola

    2013-06-01

    Full Text Available Sphoeroides testudineus, es una especie dominante en los sistemas costeros de Yucatán. Debido a su amplia distribución, ocurrencia y abundancia realiza un importante papel funcional en los ecosistemas costeros. Evaluamos para esta especie las preferencias tróficas y su variación a nivel espacial y temporal en la laguna de Ría Lagartos, un ecosistema hiperhalino localizado al noroeste de la península de Yucatán. Los especímenes fueron recolectados bimensualmente durante dos periodos anuales (2004-2005 y 2007-2008 en 23 sitios distribuidos a lo largo del sistema en cuatro zonas (marina, canal, Coloradas oeste y Coloradas este. Las variaciones tróficas espaciales y temporales fueron evaluadas mediante un análisis de correspondencia canónica (ACC. En un total de 382 individuos, se obtuvieron 68 recursos alimenticios incluidos en 20 grupos tróficos. El mayor índice de importancia relativa (IIR lo obtuvieron los bivalvos, gasterópodos y macrófitas. La variación trófica estacional mostró que los bivalvos y gasterópodos son consumidos a lo largo del año, mientras que las macrófitas constituyeron el alimento preferencial en la temporada de lluvias y nortes. La variación espacial indica un bajo consumo de gasterópodos hacia el interior de la laguna, y lo opuesto sucedió con los bivalvos. El consumo de macrófitas pudo ser debido a su mayor abundancia durante lluvias y en la zona del canal. El ACC mostró que la variación trófica espacial se debió a la abundancia de las presas preferenciales (bivalvos y gasterópodos, mientras que las diferencias estacionales por las presas secundarias (anfípodos, huevos, nematodos, braquiuros, detritus, nemátodos. Los resultados contribuyen al conocimiento biológico de la especie y resaltan la importancia y función trófica de Sphoeroides testudineus en las transferencias de energía desde el bentos hacia los niveles tróficos superiores de la cadena alimenticia.

  8. Prevalencia del protozoario Perkinsus sp. en un cultivo de ostión japonés Crassostrea gigas en Sinaloa, México

    OpenAIRE

    Villanueva-Fonseca,Lizeth Carolina; Escobedo-Bonilla,César Marcial

    2013-01-01

    Crassostrea gigas es un molusco bivalvo de gran importancia comercial. En el noroeste de México su producción es afectada por mortalidades cuyo origen infeccioso no ha sido determinado claramente. En este trabajo se determinó la prevalencia e intensidad de la infección por Perkinsus sp. en un cultivo de C. gigas en el ciclo 2011-2012. El cultivo se hizo en un sistema de línea suspendida con densidades de 28 y 42 ostiones/canasta y se determinó un tamaño de muestra de 30 ostiones por mes. La d...

  9. Poliploidia en moluscos de importancia comercial (almeja catarina Argopecten ventricosus Sowerby ii, 1842; almeja mano de leon Nodipecten subnodosus Sowerby 1835; y abulón rojo Haliotis rufescens Swainson 1822)

    OpenAIRE

    Maldonado Amparo, Rosalío

    2003-01-01

    La poliploidía ha sido una de las biotecnologías más empleadas en la ultima década para el mejoramiento genético de moluscos bivalvos por ser una de las mejores alternativas a corto plazo para incrementar la producción. Los organismos triploides presentan tres juegos completos de cromosomas homólogos que afectan la sinapsis, lo cual da como resultado una esterilidad parcial o total, la cual teóricamente repercute favorablemente en el crecimiento. Sin embargo, la inducción a la triploidía pres...

  10. DESARROLLO DE PROCESOS Y TECNOLOGIAS PARA EL DISEÑO Y DIMENSIONAMIENTO DE UN MODULO DE DETOXIFICACION DE MOLUSCOS VIVOS DE IMPORTANCIA COMERCIAL

    OpenAIRE

    SIMPFENDORFER K., ROBERT

    2013-01-01

    El presente proyecto Fondef tuvo como objetivo central el investigar metodologías de detoxificación de toxinas tipo VPM (veneno paralizante) en 3 moluscos bivalvos vivos, de interés comercial (pesquería artesanal y mitilicultura), como lo son chorito, almeja y cholga. Se estudió procedimientos biológicos y fisico-químicos de detoxificación con el objeto de validar metodologías viables para el diseño y dimensionamiento de módulos de detoxificación aplicables industrialmente. El ...

  11. Lectins with Potential for Anti-Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Tammy Yau

    2015-02-01

    Full Text Available This article reviews lectins of animal and plant origin that induce apoptosis and autophagy of cancer cells and hence possess the potential of being developed into anticancer drugs. Apoptosis-inducing lectins encompass galectins, C-type lectins, annexins, Haliotis discus discus lectin, Polygonatum odoratum lectin, mistletoe lectin, and concanavalin A, fucose-binding Dicentrarchus labrax lectin, and Strongylocentrotus purpuratus lectin, Polygonatum odoratum lectin, and mistletoe lectin, Polygonatum odoratum lectin, autophagy inducing lectins include annexins and Polygonatum odoratum lectin.

  12. The "lecithotrophic" sea urchin Heliocidaris erythrogramma lacks typical yolk platelets and yolk glycoproteins.

    Science.gov (United States)

    Scott, L B; Lennarz, W J; Raff, R A; Wray, G A

    1990-03-01

    The sea urchin Heliocidaris tuberculata undergoes typical development, forming an echinoid pluteus larva, whereas H. erythrogramma undergoes direct development via a highly modified, nonfeeding larva. Using a polyclonal antibody prepared against yolk glycoproteins from the typical developer Stronglyocentrotus purpuratus, we found that H. tuberculata contains cross-reactive proteins in abundance, but H. erythrogramma does not. In addition, we used immunoelectron microscopy to demonstrate that unfertilized eggs of H. tuberculata contain yolk platelets, but those of H. erythrogramma do not.

  13. Organization of an echinoderm Hox gene cluster

    OpenAIRE

    Martinez, Pedro; Rast, Jonathan P.; Arenas-Mena, César; Davidson, Eric H.

    1999-01-01

    The Strongylocentrotus purpuratus genome contains a single ten-gene Hox complex >0.5 megabase in length. This complex was isolated on overlapping bacterial artificial chromosome and P1 artificial chromosome genomic recombinants by using probes for individual genes and by genomic walking. Echinoderm Hox genes of Paralog Groups (PG) 1 and 2 are reported. The cluster includes genes representing all paralog groups of vertebrate Hox clusters, except that there is a sing...

  14. Dicty_cDB: Contig-U05011-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 4 1.0 3 ( FG289817 ) 1108793307980 New World Screwworm Egg 9261 ESTs C... 38 1.3 3 ( AC176252 ) Strongylocen...trotus purpuratus clone R3-3060I22, W... 40 1.3 4 ( FG290522 ) 1108793323765 New World... Screwworm Egg 9261 ESTs C... 38 1.4 3 ( FG286635 ) 1108770723708 New World Screwworm Egg 9261 ESTs C..

  15. Marine Bacteria with antimicrobials capacity isolated from cultures of bivalve mollusks

    OpenAIRE

    Fabiola Pellon; Rita Orozco; Jorge León

    2014-01-01

    Microorganisms have commonly been studied as producers of antibacterial substances; yet they are also considered producers of antifungic, antiviral, antiparasitic, citotoxics and inhibitory of other forms of cellular growth substances. This paper describes the isolation, inhibitory potential and phenotipic characterization of native bacterial strains associated to bivalve mollusks such as Argopecten purpuratus “concha de abanico” and Crassostrea gigas “ostra” in cultivation systems. From ...

  16. The biologically active form of the sea urchin egg receptor for sperm is a disulfide-bonded homo-multimer

    OpenAIRE

    1994-01-01

    Since many cell surface receptors exist in their active form as oligomeric complexes, we have investigated the subunit composition of the biologically active sperm receptor in egg plasma membranes from Strongylocentrotus purpuratus. Electrophoretic analysis of the receptor without prior reduction of disulfide bonds revealed that the surface receptor exists in the form of a disulfide-bonded multimer, estimated to be a tetramer. These findings are in excellent agreement with the fact that the N...

  17. Gamete traits influence the variance in reproductive success, the intensity of sexual selection, and the outcome of sexual conflict among congeneric sea urchins.

    Science.gov (United States)

    Levitan, Don R

    2008-06-01

    Sea-urchin species differ in susceptibility to sperm limitation and polyspermy, but the influences of gamete traits on reproductive variance, sexual selection, and sexual conflict are unknown. I compared male and female reproductive success of two congeners at natural densities in the sea. The eggs of the species occurring at higher densities, Strongylocentrotus purpuratus, require higher sperm concentrations for fertilization but are more resistant to polyspermy compared to S. franciscanus. Both species show high variance in male fertilization success at all densities and high variance in female success at low densities, but they differ in female variance at high densities, where only S. franciscanus shows high female variance. The intensity of sexual selection based on Bateman gradients is high in males of both species, variable in S. franciscanus females, and low in S. purpuratus females. Strongylocentrotus franciscanus females experience sexual selection at low densities and sexual conflict at high densities. Strongylocentrotus purpuratus may rarely experience sperm limitation and may have evolved to ameliorate sexual conflict. This reduces the variance in female fertilization, providing females with more control over fertilization. Sperm availability influences sexual selection directly by determining sperm-egg encounter probabilities and indirectly through selection on gamete traits that alter reproductive variances.

  18. Distribución del género Diplodon (Mollusca: Bivalvia: Hyriidae en territorio Argentino mediante el uso de Colecciones Biológicas

    Directory of Open Access Journals (Sweden)

    Santiago Hernán Torres

    2013-10-01

    Full Text Available Los bivalvos nacaríferos dulciacuícolas (“náyades”, son especies infaunales, endémicas de la RegiónNeotropical, pertenecientes a las familias Hyriidae (Swaison, 1840 y Etheriidae (Swaison, 1840. La alteración del ambiente y la competencia con especies invasoras como Corbicula fluminea (Müller, 1774 y Limnoperna fortunei (Dunker, 1857, impactan sobre las poblaciones naturales. En esta comunicación, se presenta el inicio de un Proyecto de investigación sobre la distribución geográfica de las especies del género Diplodon en la Argentina. Estas especies son un componente importante de la infauna de los cuerpos lóticos y lénticos, viviendo en fondos limosos, limo-arenosos, excepcionalmente en sustratos duros, con un régimen nutricio filtrador, teniendo un papel importante como recicladores de materia orgánica. Conocer la distribución de los bivalvos pertenecientes al género Diplodon en el territorio Argentino permitirá el reconocimiento de potenciales áreas prioritarias para su conservación. Sobre la base de la bibliografía disponible y los ejemplares de las especies del genero Diplodon depositados en la Colección Malacológica del Museo de La Plata (FCNyM-UNLP, se confeccionó una matriz de datos que incluye la identificación del ejemplar, la colección en que se encuentra depositado, el número de catálogo, la localidad y la fecha de colecta. Cada localidad fue ubicada mediante el uso de cartas geográficas de Argentina y revisiones bibliográficas en imágenes satelitales de GoogleEarth, asignando las coordenadas para cada punto. Como resultado del trabajo se obtiene la distribución de estas especies nativas y se discute el grado de solapamiento con las dos especies de bivalvos invasores y el impacto de actividades humanas. 

  19. Hábitos alimenticios de Sphoeroides testudineus (Perciformes: Tetraodontidae en el sistema lagunar de Ría Lagartos, Yucatán, México Feeding habits of Sphoeroides testudineus (Perciformes: Tetraodontidae in the lagoon system of Ria Lagartos, Yucatán, Mexico

    Directory of Open Access Journals (Sweden)

    Ariel Adriano Chi-Espínola

    2013-06-01

    Full Text Available Sphoeroides testudineus, es una especie dominante en los sistemas costeros de Yucatán. Debido a su amplia distribución, ocurrencia y abundancia realiza un importante papel funcional en los ecosistemas costeros. Evaluamos para esta especie las preferencias tróficas y su variación a nivel espacial y temporal en la laguna de Ría Lagartos, un ecosistema hiperhalino localizado al noroeste de la península de Yucatán. Los especímenes fueron recolectados bimensualmente durante dos periodos anuales (2004-2005 y 2007-2008 en 23 sitios distribuidos a lo largo del sistema en cuatro zonas (marina, canal, Coloradas oeste y Coloradas este. Las variaciones tróficas espaciales y temporales fueron evaluadas mediante un análisis de correspondencia canónica (ACC. En un total de 382 individuos, se obtuvieron 68 recursos alimenticios incluidos en 20 grupos tróficos. El mayor índice de importancia relativa (IIR lo obtuvieron los bivalvos, gasterópodos y macrófitas. La variación trófica estacional mostró que los bivalvos y gasterópodos son consumidos a lo largo del año, mientras que las macrófitas constituyeron el alimento preferencial en la temporada de lluvias y nortes. La variación espacial indica un bajo consumo de gasterópodos hacia el interior de la laguna, y lo opuesto sucedió con los bivalvos. El consumo de macrófitas pudo ser debido a su mayor abundancia durante lluvias y en la zona del canal. El ACC mostró que la variación trófica espacial se debió a la abundancia de las presas preferenciales (bivalvos y gasterópodos, mientras que las diferencias estacionales por las presas secundarias (anfípodos, huevos, nematodos, braquiuros, detritus, nemátodos. Los resultados contribuyen al conocimiento biológico de la especie y resaltan la importancia y función trófica de Sphoeroides testudineus en las transferencias de energía desde el bentos hacia los niveles tróficos superiores de la cadena alimenticia.Sphoeroides testudineus is a

  20. The vertical distribution and abundance of gastropods and bivalves from rocky beaches of Cuastecomate Bay, Jalisco. México

    Directory of Open Access Journals (Sweden)

    M. C Esqueda

    2000-12-01

    Full Text Available The vertical distribution and abundance of conspicuous gastropod and bivalve species were studied at five rocky beaches in Cuastecomate Bay, Jalisco. Sampling was done from September, 1993 through March, 1994 with 0.75 m2 quadrants placed along replicate transect lines (10 m long in the supralittoral and mesolittoral (upper, middle and lower intertidal zones. A total of 6 643 mollusks were collected. Gastropods dominated the samples (6 272 individuals, 44 species; the bivalves were less abundant and diverse (371 individuals, five species. Seventeen species comprised 89.8% of all individuals collected. The gastropods Nodilittorina aspera and Nerita scabricosta were the most abundant with 637.8 and 71.43 individuals/m2, respectively. The most abundant bivalves were Brachidontes adamsianus and Chloromytilus palliopunctatus with 60.7 and 61.3 individuals/m2 respectively. The abundance of gastropods decreased from the supralittoral to the lower tidal zones while the number of species increased in the same direction. The number of species of bivalves also increased from the supralittoral to the lower intertidal zone; the abundance of individuals was higher at the middle intertidal zone. Affinities between groups of species among sampling stations were identified by computing Pearson’s correlation coefficient using abundance values (ind./m2 and Jaccard's dissimilarity index using species presence or absence in the lower intertidal zone. Affinity among stations was not dependent upon their vicinity but on the high dominance of few species, the occurrence of many secondary species and beach characteristics.Se presenta la distribución y abundancia de las especies conspicuas de gastrópodos y bivalvos encontradas en cinco playas rocosas de la Bahía Cuatecomate, Jalisco. El muestreo se realizó desde septiembre de 1993 hasta marzo de 1994 usando cuadrantes de 0.75 m2 colocados a lo largo de líneas de transectos (longitud = 10 m en réplica, en las

  1. Modelación del crecimiento individual del callo de hacha Atrina maura (Bivalvia: Pinnidae a partir de la inferencia multi modelo

    Directory of Open Access Journals (Sweden)

    Eugenio Alberto Aragón-Noriega

    2013-09-01

    Full Text Available El molusco bivalvo Atrina maura (Sowervy 1835 habita aguas marinas someras y estuarios en la costa del Pacífico desde Baja California, México hasta Perú. Es un organismo cuyo crecimiento individual ha sido insuficientemente modelado. El objetivo del estudio fue modelar su crecimiento individual absoluto mediante el uso de datos de longitud a la edad obtenidos de una región del Golfo de California. Los parámetros fueron obtenidos con el uso de cinco modelos de crecimiento; von Bertalanffy, Gompertz, Logístico, Caso 1 de Schnute y Schnute & Richards. Se seleccionó el mejor modelo usando el criterio de información de Akaike, AIC, pero se calcularon también la suma de residuos al cuadrado y la R² ajustada. Para obtener la longitud asintótica se siguió el enfoque de inferencia multi modelo IMM. Según el AIC el modelo que mejor describe el crecimiento absoluto de A. maura es el de Gompertz y colocó en cuarto lugar jerárquico el de von Bertalanffy. La longitud asintótica promedio encontrada, siguiendo la IMM, fue de 218.9mm (IC 212.3-225.5 de longitud de concha. Se concluye que tanto la IMM como el AIC representan las herramientas más sólidas para evaluar parámetros de crecimiento individual de A. maura y que el modelo de crecimiento de von Bertalanffy no debe ser seleccionado a priori como la opción para describir el crecimiento individual en moluscos bivalvos como la especie estudiada.

  2. The test skeletal matrix of the black sea urchin Arbacia lixula.

    Science.gov (United States)

    Kanold, Julia M; Immel, Francoise; Broussard, Cédric; Guichard, Nathalie; Plasseraud, Laurent; Corneillat, Marion; Alcaraz, Gérard; Brümmer, Franz; Marin, Frédéric

    2015-03-01

    In the field of biomineralization, the past decade has been marked by the increasing use of high throughput techniques, i.e. proteomics, for identifying in one shot the protein content of complex macromolecular mixtures extracted from mineralized tissues. Although crowned with success, this approach has been restricted so far to a limited set of key-organisms, such as the purple sea urchin Strongylocentrotus purpuratus, the pearl oyster or the abalone, leaving in the shadow non-model organisms. As a consequence, it is still unknown to what extent the calcifying repertoire varies, from group to group, at high (phylum, class), median (order, family) or low (genus, species) taxonomic rank. The present paper shows the first biochemical and proteomic characterization of the test matrix of the Mediterranean black sea urchin Arbacia lixula (Arbacioida). Our work suggests that the skeletal repertoire of A. lixula exhibits some similarities but also several differences with that of the few sea urchin species (S. purpuratus, Paracentrotus lividus), for which molecular data are already available. The differences may be attributable to the taxonomic position of the species considered: A. lixula belongs to an order - Arbacioida - that diverged more than one hundred million years ago from the Camarodonta, which includes the two species S. purpuratus and P. lividus. For the echinoid class, we suggest that large-scale proteomic screening should be performed in order to understand which molecular functions related to calcification are conserved and which ones have been co-opted for biomineralization in particular lineages. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Current Status of Echinoderm Genome Analysis - What do we Know?

    Science.gov (United States)

    Kondo, Mariko; Akasaka, Koji

    2012-01-01

    Echinoderms have long served as model organisms for a variety of biological research, especially in the field of developmental biology. Although the genome of the purple sea urchin Strongylocentrotus purpuratus has been sequenced, it is the only echinoderm whose whole genome sequence has been reported. Nevertheless, data is rapidly accumulating on the chromosomes and genomic sequences of all five classes of echinoderms, including the mitochondrial genomes and Hox genes. This blossoming new data will be essential for estimating the phylogenetic relationships among echinoderms, and also to examine the underlying mechanisms by which the diverse morphologies of echinoderms have arisen. PMID:23024605

  4. Aislamiento de enterobacterias en algunos moluscos del mar peruano

    Directory of Open Access Journals (Sweden)

    Dora A. Taboada P.

    2014-06-01

    Full Text Available En este trabajo se da a conocer el resultado de un estudio bacteriológico en 5 especies de moluscos que se utilizan en la alimentación humana, ellos fueron: Aulacomya ater, Gari sp., Mesodesma donacium, Aequipecten purpuratus y Thais chocolata, obtenidos de diversos centros de expendio del Callao y Lima. Se aisló Salmonella enteritidis serotipo Derby y Edwardsiella de Gari sp. Otras bacterias como Proteus, Citrobacter, Enterobacter y Serratia estuvieron presentes en los diversos moluscos. El 100% de ellos presentó contaminación por E. coli.

  5. Kelp forest monitoring 1993 annual report. Channel Islands National Park. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kushner, D.; Walder, R.; Gorodezky, L.; Lerma, D.; Richards, D.

    1993-06-01

    The 1993 results of the Channel Islands National Park Kelp Forest Monitoring Project are described in this report. Population dynamics of 68 taxa or categories of algea, fish, and invertebrates were measured at 16 permanent sites around the five islands within the park. Survey techniques utilized SCUBA and surface-supplied-air, and included quadrats, band transects, random contacts, fish transects, video transects, size frequency measurements, artificial recruitment modules, and species list surveys. Temperature data was collected using Sea Data batheothermographs, and HOBOTEMP temperature loggers. Temperature loggers were installed at each of the sixteen sites. Size frequency measurements were taken from artifical recruitment modules at nine sites. In 1993, 13 sites had giant kelp, Macrocysts pyrifera, forests, one site was dominated by the aggregating red sea cucumber, pachythyone rubra, one site was dominated by red sea urchins, Strongylocentrotus franciscanus, and another by purple sea urchins, S. purpuratus. The 13 sites with kelp forests consisted of 10 mature and three young kelp forests. Wasting disease was observed in sea stars and wasting syndrome was apparent in sea urchins. Sea urchins wasting syndrome appears to have caused mass mortality of purple sea urchins, S. purpuratus, at two Santa Barbara Island sites.

  6. Scanning electron microscopy study of adhesion in sea urchin blastulae. M.S. Thesis

    Science.gov (United States)

    Crowther, Susan D.

    1988-01-01

    The dissociation supernatant (DS) isolated by disaggregating Strongylocentrotus purpuratus blastulae in calcium- and magnesium-free seawater specifically promotes reaggregation of S. purpuratus blastula cells. The purpose of this study was to use scanning electron microscopy to examine the gross morphology of aggregates formed in the presence of DS to see if it resembles adhesion in partially dissociated blastulae. A new reaggregation procedure developed here, using large volumes of cell suspension and a large diameter of rotation, was utilized to obtain sufficient quantities of aggregates for scanning electron microscopy. The results indicate that aggregates formed in the presence of DS resemble partially dissociated intact embryos in terms of the direct cell-cell adhesion observed. DS did not cause aggregation to form as a result of the entrapment of cells in masses of extracellular material. These studies provide the groundwork for further studies using transmission electron microscopy to more precisely define the adhesive contacts made by cells in the presence of the putative adhesion molecules present in DS.

  7. Annual reversible plasticity of feeding structures: cyclical changes of jaw allometry in a sea urchin.

    Science.gov (United States)

    Ebert, Thomas A; Hernández, José Carlos; Clemente, Sabrina

    2014-03-22

    A wide variety of organisms show morphologically plastic responses to environmental stressors but in general these changes are not reversible. Though less common, reversible morphological structures are shown by a range of species in response to changes in predators, competitors or food. Theoretical analysis indicates that reversible plasticity increases fitness if organisms are long-lived relative to the frequency of changes in the stressor and morphological changes are rapid. Many sea urchin species show differences in the sizes of jaws (demi-pyramids) of the feeding apparatus, Aristotle's lantern, relative to overall body size, and these differences have been correlated with available food. The question addressed here is whether reversible changes of relative jaw size occur in the field as available food changes with season. Monthly samples of the North American Pacific coast sea urchin Strongylocentrotus purpuratus were collected from Gregory Point on the Oregon (USA) coast and showed an annual cycle of relative jaw size together with a linear trend from 2007 to 2009. Strongylocentrotus purpuratus is a long-lived species and under field conditions individuals experience multiple episodes of changes in food resources both seasonally and from year to year. Their rapid and reversible jaw plasticity fits well with theoretical expectations.

  8. Sea urchin akt activity is Runx-dependent and required for post-cleavage stage cell division

    KAUST Repository

    Robertson, Anthony J.

    2013-03-25

    In animal development following the initial cleavage stage of embryogenesis, the cell cycle becomes dependent on intercellular signaling and controlled by the genomically encoded ontogenetic program. Runx transcription factors are critical regulators of metazoan developmental signaling, and we have shown that the sea urchin Runx gene runt-1, which is globally expressed during early embryogenesis, functions in support of blastula stage cell proliferation and expression of the mitogenic genes pkc1, cyclinD, and several wnts. To obtain a more comprehensive list of early runt-1 regulatory targets, we screened a Strongylocentrotus purpuratus microarray to identify genes mis-expressed in mid-blastula stage runt-1 morphants. This analysis showed that loss of Runx function perturbs the expression of multiple genes involved in cell division, including the pro-growth and survival kinase Akt (PKB), which is significantly underexpressed in runt-1 morphants. Further genomic analysis revealed that Akt is encoded by two genes in the S. purpuratus genome, akt-1 and akt-2, both of which contain numerous canonical Runx target sequences. The transcripts of both genes accumulate several fold during blastula stage, contingent on runt-1 expression. Inhibiting Akt expression or activity causes blastula stage cell cycle arrest, whereas overexpression of akt-1 mRNA rescues cell proliferation in runt-1 morphants. These results indicate that post-cleavage stage cell division requires Runx-dependent expression of akt.

  9. Estado del conocimiento de la durofagia en el registro fósil: interacción depredador-presa en moluscos marinos (Clases Gastropoda y Bivalvia

    Directory of Open Access Journals (Sweden)

    Catalina Gómez-Espinosa

    2015-01-01

    Full Text Available La depredación como un mecanismo evolutivo, de diversificación y biomineralización es un tópico de gran interés. Un tipo específico de depredación es la durofagia que se define como el hábito alimenticio de los animales que consumen organismos con un esqueleto duro mineralizado, ya sea concha o exoesqueleto. Los moluscos representan una fuente muy importante para examinar la depredación durófaga en el registro fósil debido a su distribución mundial, abundancia, buena preservación y a que habitan en una gran variedad de ambientes. En este trabajo se revisa el número de artículos publicados en revistas de circulación internacional que se enfocan en el tema de la durofagia y que tienen como potenciales presas a gasterópodos y bivalvos marinos fósiles. Se recuperaron y revisaron 101 artículos sobre este tema, enfocados en seis tipos de evidencia: perforación, reparación y fragmentación de la concha, mordidas, “punctures” y coprolitos. La mayoría de los ejemplos correspondieron a moluscos del Cenozoico. En general hay más registros en la zona tropical. Durante el Paleozoico, la mayoría de las veces, no se identificó el potencial depredador; esta tendencia continuó en el Mesozoico pero se reconoció la depredación de gasterópodos y bivalvos por parte de gasterópodos carnívoros, artrópodos, peces y reptiles. Durante el Cenozoico dominó la depredación por parte de gasterópodos natícidos y murícidos y se reconoció también la depredación por parte de ar trópodos, peces y mamíferos.

  10. Evaluación in vitro de sustancias antibacterianas producidas por bacterias aisladas de diferentes organismos marinos

    Directory of Open Access Journals (Sweden)

    Isabel Castillo

    2001-12-01

    Full Text Available Se realizaron antibiogramas directos para detectar la presencia de bacterias productoras de sustancias antibacterianas aisladas de diferentes organismos marinos, utilizando el patógeno de humanos Staphylococcus aureus ATCC6538 como germen revelador. Alas bacterias que produjeron sustancias inhibidoras del crecimiento del germen revelador se les realizó pruebas morfológicas, fisiológicas y bioquímicas en función de identificarlas a nivel de género. De un total de 290 cepas 54 (18.6 % inhibieron el crecimiento del germen revelador, pero sólo 27 se mantuvieron viables. Los grupos más representativos de donde se aislaron las bacterias productoras de sustancias antibacterianas fueron los moluscos bivalvos, las esponjas y corales, presentaron un 41.2, 33.3 y 29.7 %, respectivamente, de bacterias productoras relativas al número de sus aislados. Los organismos que presentaron una mayor proporción de bacterias inhibidoras del germen revelador se aislaron del coral Madracis decactis (62.5 %, la esponja Cliona sp. (57.1 %, y el octocoral Plexaura flexuosa (50.0 %. De las 27 cepas productoras de sustancias antibacterianas que se identificaron, 51.85 % pertenecieron al género Aeromonas y 14.8% al género Vibro. Los resultados muestran la abundancia de bacterias marinas productoras de sustancias antibacterianas, la mayoría de ellas pertenecientes al grupo de las vibrionáceas principalmente aisladas de corales y moluscos bivalvosBacteria from several groups of marine organisms were isolated and, using direct antibiograms, identified those that produce antibacterial substances, using a human pathogenic strain of Staphylococcus aureus ATCC6538 as revealing microorganism. Bacteria which produce substances that inhibite S. aureus growth were identified through morphological, physiological and biochemical tests. Out of 290 bacteria, 54 (18.6 % inhibited the growth of S. aureus, but only 27 survived for identification. Bivalves, sponges and corals were

  11. Cambios alimenticios en tres especies de Sphoeroides (Tetraodontiformes: Tetraodontidae posterior al huracán Isidoro en Bocana de la Carbonera, Sureste del Golfo de México

    Directory of Open Access Journals (Sweden)

    Sonia Eugenia Palacios-Sánchez

    2010-12-01

    Full Text Available Se analizan los cambios producidos por el huracán Isidoro en la repartición de los recursos alimenticios de tres especies de peces de la familia Tetraodontidae (Sphoeroides nephelus, S. spengleri y S testudineus que cohabitan en la Bocana de la Carbonera (sureste del Golfo de México. Los Sphoeroides spp. basaron su alimentación en los organismos bentónicos, sobresaliendo por su consumo el mejillón (Brachidontes sp., la lapa (Balanus sp. y gasterópodos (Crepidula sp.. Previo al impacto del huracán, las tres especies utilizaron de forma diferencial los recursos alimenticios disponibles (bivalvos, gasterópodos, cirrípedos y decápodos recurriendo a diferentes estrategias que les permitieron minimizar la competencia interespecífica y coexistir. Posterior al impacto, la disponibilidad de las presas disminuyó y la competencia interespecífica por el alimento se incrementó provocando que S. testudineus y S. nephelus cambiaran su espectro trófico (xiphosuros, anfípodos, isópodos y detritus desplazando a S. spengleri de la bocana. La repartición de los recursos alimenticios estuvo condicionada por la abundancia y diversidad de las presas así como la respuesta adaptativa de cada especie.

  12. COLONIZACIÓN DE MOLUSCOS Y CRUSTÁCEOS EN RAÍCES DE MANGLE ROJO EN UNA LAGUNA COSTERA DE LA PUNTA NORTE DEL GOLFO DE MORROSQUILLO

    Directory of Open Access Journals (Sweden)

    PRÜSMANN JOHANNA

    2010-05-01

    Full Text Available Se evaluaron la colonización y sucesión de moluscos y crustáceos en un sustrato de raíces de mangle en tres estaciones en la ciénaga La Boquilla, Punta San Bernardo en la parte norte del Golfo de Morrosquillo. Para el seguimiento del proceso de colonización se ubicaron tres sitios en las márgenes occidental, norte y oriental, y se fijaron en cada estación seis raíces aéreas deshojadas de Rhizophora mangle. Luego de 76 y 200 días de exposición, se retiraron tres raíces de cada sitio y se identificaron los organismos por morfoespecie. Después de 200 días de exposición, se determinaron 19 especies de moluscos y cinco de crustáceos. El anfípodo Corophium sp. y el bivalvo Brachidontes exustus fueron las especies mas numerosas y agruparon una fracción muy importante de la totalidad de los individuos recolectados. La mayoría de las especies encontradas son típicas de la fauna acompañante de las raíces de mangle en el Caribe colombiano.

  13. Algunos aspectos relacionados con las enfermedades tropicales transmitidas por moluscos

    Directory of Open Access Journals (Sweden)

    A. Mijail Pérez

    1999-12-01

    Full Text Available Muchas especies de moluscos son hospedantes de diversos parásitos que provocan infecciones muy serias e incluso mortales en seres humanos y ganado. La esquistosomiasis extendida por 74 países, infecta a unos 200 millones de personas y está en segundo lugar, después de la malaria, como causa de la mortalidad humana originada por parásitos. La infección es causada por un platelminto que se desarrolla en caracoles de agua dulce y que desde el agua puede penetrar en la piel de un ser humano y desarrollarse dentro de sus órganos, produciendo distintos grados de infección, hasta provocar la muerte. Distintas especies de esos caracoles están extendidas por Centro América. El cólera, otra enfermedad que también es mortal, se ha encontrado en moluscos bivalvos comestibles colectados en el Golfo de Nicoya, que bordea Nicaragua y Costa Rica Estas epidemias se pueden combatir con diversos métodos de control de los caracoles hospedantes de parásitos.

  14. APORTE AL CONOCIMIENTO DE LOS MACROINVERTEBRADOS ASOCIADOS A LAS RAICES DEL MANGLE (Rizophora mangle EN LA CIENAGA LA BOQUILLA, MUNICIPIO DE SAN ONOFRE, SUCRE.

    Directory of Open Access Journals (Sweden)

    QUICENO CUARTAS PAULA ANDREA

    2010-05-01

    Full Text Available Con el fin de establecer la estructura de la comunidad de macroinvertebrados asociados a las raíces del mangle rojo Rizophora mangle en la ciénaga La Boquilla, se muestreó cuatro veces en cinco estaciones entre febrero y agosto de 1999. En cada estación, se retiraron de dos a cinco raíces y cuantificó el número y la cobertura de los macroinvertebrados asociados. En general, en la ciénaga La Boquilla se mantienen temperaturas altas con ligeras fluctuaciones a través del tiempo. En forma similar, la salinidad permaneció en niveles superiores a 30 UPS con sólo ligeras fluctuaciones. En total se capturaron 33 morfoespecies, la mayoría de origen marino y con un marcado carácter estenohalino. Entre las especies encontradas, los bivalvos presentaron las mayores áreas de cubrimiento y abundancia, en general, la composición de la comunidad asociada a las raíces no varió significativamente en el tiempo y en el espacio. El número de especies y la diversidad fueron bajos en comparación con otros ambientes lagunares del Caribe colombiano.

  15. SEM and x-ray microanalysis of cellular differentiation in Sea Urchin Embryos: a frozen hydrated study

    International Nuclear Information System (INIS)

    Klein, S.B.

    1985-12-01

    Quantitative studies of major chemical element distribution among individual differentiating cells were attempted using scanning electron microscopy. Frozen hydrated embryos of the sea urchin Strongelocentrotus purpuratus were examined at three stages: blastula, mesenchyme blastula, and early gastrula. The blastocoel matrix contained large beads of approximately 1 μm diameter. The cells of the archenteron lacked well defined cell boundaries. Characteristic levels of beam damage and charging provided structural information. The primary mesenchyme cells within the blastocoel were particularly susceptible to both effects. Damaging effects were noted in material stored in liquid nitrogen longer than three months. Ice crystal growth, shrinkage, elemental shift, density changes and charge accumulation may take place in these stored specimens. 151 refs., 50 figs., 3 tabs

  16. A partial skeletal proteome of the brittle star Ophiocoma wendtii

    Science.gov (United States)

    Seaver, Ryan W.

    The formation of mineralized tissue was critical to the evolution and diversification of metazoans and remains functionally significant in most animal lineages. Of special importance is the protein found occluded within the mineral matrix, which facilitates the process of biomineralization and modulates the final mineral structure. These skeletal matrix proteins have well been described in several species, including the sea urchin Stronglyocentrotus purpuratus, an important model organism. Biomineralization research is limited in other echinoderm classes. This research encompasses the first description of mineral matrix proteins in a member of the echinoderm class Ophiuroidea. This work describes the skeletal matrix proteins of the brittle star Ophiocoma wendtii using bioinformatic and proteomic techniques. General characteristics of matrix protein are described and a number of candidate biomineralization related genes have been identified, cloned, and sequenced. The unique evolutionary and biochemical properties of brittle star skeletal matrix proteins are also described.

  17. Phase transitions in biogenic amorphous calcium carbonate.

    Science.gov (United States)

    Gong, Yutao U T; Killian, Christopher E; Olson, Ian C; Appathurai, Narayana P; Amasino, Audra L; Martin, Michael C; Holt, Liam J; Wilt, Fred H; Gilbert, P U P A

    2012-04-17

    Crystalline biominerals do not resemble faceted crystals. Current explanations for this property involve formation via amorphous phases. Using X-ray absorption near-edge structure (XANES) spectroscopy and photoelectron emission microscopy (PEEM), here we examine forming spicules in embryos of Strongylocentrotus purpuratus sea urchins, and observe a sequence of three mineral phases: hydrated amorphous calcium carbonate (ACC · H(2)O) → dehydrated amorphous calcium carbonate (ACC) → calcite. Unexpectedly, we find ACC · H(2)O-rich nanoparticles that persist after the surrounding mineral has dehydrated and crystallized. Protein matrix components occluded within the mineral must inhibit ACC · H(2)O dehydration. We devised an in vitro, also using XANES-PEEM, assay to identify spicule proteins that may play a role in stabilizing various mineral phases, and found that the most abundant occluded matrix protein in the sea urchin spicules, SM50, stabilizes ACC · H(2)O in vitro.

  18. Dicty_cDB: Contig-U15045-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available e) Bacillus anthracis str. CDC 684... 286 2e-75 EU302126_1( EU302126 |pid:none) Luciola terminali... AE006470_46( AE006470 |pid:none) Chlorobium tepidum TLS, complete ... 207 2e-51 AM494956_128( AM494956 |pid...centrotus purpuratus clone R3-42P23, WOR... 36 0.051 11 ( EK354403 ) 1095468426890 Global-Ocean-Sampling_GS-...** SEQUENCI... 38 0.25 13 ( EJ594751 ) 1092961073324 Global-Ocean-Sampling_GS-29-01-01-1... 40 0.26 2 ( BA00...170 ) 1093018401251 Global-Ocean-Sampling_GS-36-01-01-2... 50 0.35 1 ( ER486373 ) 1093015301415 Global-Ocean-Sampli

  19. Dicty_cDB: Contig-U15813-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available purpuratus... 32 4.9 3 ( FL641392 ) TS04-B2 Reticulitermes flavipes symbiont library ... 34 5.0 3 ( FE94079... AC102207 ) Mus musculus chromosome 1, clone RP24-262A17, com... 50 0.41 1 ( EJ558886 ) 1092959528858 Global-Ocean-Sampli...ng_GS-29-01-01-1... 50 0.41 1 ( EJ552305 ) 1092959463211 Global-Ocean-Sampli...) 1095460136297 Global-Ocean-Sampling_GS-31-01-01-1... 48 1.6 1 ( ED538584 ) KBrB132D17F KBrB, Brassica rapa BamHI BAC li...-L03.F SB_BBc Sorghum bicolor genomic 5'... 46 3.4 2 ( EJ602444 ) 1092961206927 Global-Ocean-Sampli

  20. Dicty_cDB: Contig-U06881-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available T, clone G000... 44 4.9 1 ( CB077241 ) hj51d10.g1 Hedyotis terminalis flower - Stage 2 (... 44 4.9 1 ( BI739...) 1092959732476 Global-Ocean-Sampling_GS-31-01-01-1... 36 0.16 3 ( EJ122584 ) 1092343379871 Global-Ocean-Sampli...one mth2-12f13... 38 0.28 7 ( EJ342623 ) 1092963526465 Global-Ocean-Sampling_GS-28-01-01-1... 48 0.32 1 ( CE...2 ) 1095469414961 Global-Ocean-Sampling_GS-31-01-01-1... 40 0.59 2 ( AJ871361 ) Nyctotherus ovalis partial g...180574 ) Strongylocentrotus purpuratus clone R3-3095P18, W... 46 1.2 1 ( EJ372544 ) 1092963729038 Global-Ocean-Sampli

  1. Influence of 60-Hz magnetic fields on sea urchin development

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, S.; Zimmerman, A.M.; Winters, W.D.; Cameron, I.L. (York Univ., Toronto, Ontario (Canada))

    1990-01-01

    Continuous exposure of sea urchin (Strongylocentrotus purpuratus) embryos at 18 degrees C to a cyclic 60-Hz magnetic field at 0.1 mT rms beginning 4 min after insemination caused a significant developmental delay during the subsequent 23 hours. No delay in development was recorded for periods up to 18 hours after fertilization. At 18 h, most embryos were in the mesenchyme blastula stage. At 23 h, most control embryos were in mid-gastrula whereas most magnetic-field-exposed embryos were in the early gastrula stage. Thus an estimated 1-h delay occurred between these developmental stages. The results are discussed in terms of possible magnetic-field modification of transcription as well as interference with cell migration during gastrulation. The present study extends and supports the growing body of information about potential effects of exposures to extremely-low-frequency (ELF) magnetic fields on developing organisms.

  2. The impact of gene expression variation on the robustness and evolvability of a developmental gene regulatory network.

    Directory of Open Access Journals (Sweden)

    David A Garfield

    2013-10-01

    Full Text Available Regulatory interactions buffer development against genetic and environmental perturbations, but adaptation requires phenotypes to change. We investigated the relationship between robustness and evolvability within the gene regulatory network underlying development of the larval skeleton in the sea urchin Strongylocentrotus purpuratus. We find extensive variation in gene expression in this network throughout development in a natural population, some of which has a heritable genetic basis. Switch-like regulatory interactions predominate during early development, buffer expression variation, and may promote the accumulation of cryptic genetic variation affecting early stages. Regulatory interactions during later development are typically more sensitive (linear, allowing variation in expression to affect downstream target genes. Variation in skeletal morphology is associated primarily with expression variation of a few, primarily structural, genes at terminal positions within the network. These results indicate that the position and properties of gene interactions within a network can have important evolutionary consequences independent of their immediate regulatory role.

  3. Dicty_cDB: Contig-U01028-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available , BAC clone: RNB1-142B13, 5'... 36 0.26 3 ( FC835657 ) CBHI6246.rev CBHI Metridium senile tentacle Metri... ...agen, partial cds. 40 0.89 2 ( FC834206 ) CBHI5463.fwd CBHI Metridium senile tentacle Metri... 40 0.90 2 ( C...F655243 ) tac86g11.y1 Hydra EST -IV Hydra magnipapillata cD... 40 0.90 2 ( FC836287 ) CBHI6585.fwd CBHI Metridium senile tentacle...NA ... 48 1.0 1 ( FC831009 ) CBHI3780.fwd CBHI Metridium senile tentacle Metri... 48 1.0 1 ( EY924105 ) RR4D...0 ) CBHI5256.fwd CBHI Metridium senile tentacle Metri... 40 1.1 2 ( AC178239 ) Strongylocentrotus purpuratus

  4. SEM and x-ray microanalysis of cellular differentiation in Sea Urchin Embryos: a frozen hydrated study

    Energy Technology Data Exchange (ETDEWEB)

    Klein, S.B.

    1985-12-01

    Quantitative studies of major chemical element distribution among individual differentiating cells were attempted using scanning electron microscopy. Frozen hydrated embryos of the sea urchin Strongelocentrotus purpuratus were examined at three stages: blastula, mesenchyme blastula, and early gastrula. The blastocoel matrix contained large beads of approximately 1 ..mu..m diameter. The cells of the archenteron lacked well defined cell boundaries. Characteristic levels of beam damage and charging provided structural information. The primary mesenchyme cells within the blastocoel were particularly susceptible to both effects. Damaging effects were noted in material stored in liquid nitrogen longer than three months. Ice crystal growth, shrinkage, elemental shift, density changes and charge accumulation may take place in these stored specimens. 151 refs., 50 figs., 3 tabs.

  5. Reconstructing SALMFamide Neuropeptide Precursor Evolution in the Phylum Echinodermata: Ophiuroid and Crinoid Sequence Data Provide New Insights

    Science.gov (United States)

    Elphick, Maurice R.; Semmens, Dean C.; Blowes, Liisa M.; Levine, Judith; Lowe, Christopher J.; Arnone, Maria I.; Clark, Melody S.

    2015-01-01

    The SALMFamides are a family of neuropeptides that act as muscle relaxants in echinoderms. Analysis of genome/transcriptome sequence data from the sea urchin Strongylocentrotus purpuratus (Echinoidea), the sea cucumber Apostichopus japonicus (Holothuroidea), and the starfish Patiria miniata (Asteroidea) reveals that in each species there are two types of SALMFamide precursor: an L-type precursor comprising peptides with a C-terminal LxFamide-type motif and an F-type precursor solely or largely comprising peptides with a C-terminal FxFamide-type motif. Here, we have identified transcripts encoding SALMFamide precursors in the brittle star Ophionotus victoriae (Ophiuroidea) and the feather star Antedon mediterranea (Crinoidea). We have also identified SALMFamide precursors in other species belonging to each of the five echinoderm classes. As in S. purpuratus, A. japonicus, and P. miniata, in O. victoriae there is one L-type precursor and one F-type precursor. However, in A. mediterranea only a single SALMFamide precursor was found, comprising two peptides with a LxFamide-type motif, one with a FxFamide-type motif, five with a FxLamide-type motif, and four with a LxLamide-type motif. As crinoids are basal to the Echinozoa (Holothuroidea + Echinoidea) and Asterozoa (Asteroidea + Ophiuroidea) in echinoderm phylogeny, one model of SALMFamide precursor evolution would be that ancestrally there was a single SALMFamide gene encoding a variety of SALMFamides (as in crinoids), which duplicated in a common ancestor of the Echinozoa and Asterozoa and then specialized to encode L-type SALMFamides or F-type SALMFamides. Alternatively, a second SALMFamide precursor may remain to be discovered or may have been lost in crinoids. Further insights will be obtained if SALMFamide receptors are identified, which would provide a molecular basis for experimental analysis of the functional significance of the “cocktails” of SALMFamides that exist in echinoderms. PMID:25699014

  6. Reconstructing SALMFamide neuropeptide precursor evolution in the phylum Echinodermata: ophiuroid and crinoid sequence data provide new insights

    Directory of Open Access Journals (Sweden)

    Maurice R Elphick

    2015-02-01

    Full Text Available The SALMFamides are a family of neuropeptides that act as muscle relaxants in echinoderms. Analysis of genome/transcriptome sequence data from the sea urchin Strongylocentrotus purpuratus (Echinoidea, the sea cucumber Apostichopus japonicus (Holothuroidea and the starfish Patiria miniata (Asteroidea reveals that in each species there are two types of SALMFamide precursor: an L-type precursor comprising peptides with a C-terminal LxFamide-type motif and an F-type precursor solely or largely comprising peptides with a C-terminal FxFamide-type motif. Here we have identified transcripts encoding SALMFamide precursors in the brittle star Ophionotus victoriae (Ophiuroidea and the feather star Antedon mediterranea (Crinoidea. We have also identified SALMFamide precursors in other species belonging to each of the five echinoderm classes. As in S. purpuratus, A. japonicus and P. miniata, in O. victoriae there is one L-type precursor and one F-type precursor. However, in A. mediterranea only a single SALMFamide precursor was found, comprising two peptides with a LxFamide-type motif, one with a FxFamide-type motif, five with a FxLamide-type motif and four with a LxLamide-type motif. As crinoids are basal to the Echinozoa (Holothuroidea + Echinoidea and Asterozoa (Asteroidea + Ophiuroidea in echinoderm phylogeny, one model of SALMFamide precursor evolution would be that ancestrally there was a single SALMFamide gene encoding a variety of SALMFamides (as in crinoids, which duplicated in a common ancestor of the Echinozoa and Asterozoa and then specialised to encode L-type SALMFamides or F-type SALMFamides. Alternatively, a second SALMFamide precursor may remain to be discovered or may have been lost in crinoids. Further insights will be obtained if SALMFamide receptors are identified, which would provide a molecular basis for experimental analysis of the functional significance of the cocktails of SALMFamides that exist in echinoderms.

  7. Dynamic evolution of toll-like receptor multigene families in echinoderms

    Directory of Open Access Journals (Sweden)

    Katherine M Buckley

    2012-06-01

    Full Text Available The genome of the purple sea urchin, Strongylocentrotus purpuratus, was the first to be sequenced from a long-lived large invertebrate. Analysis of this genome uncovered a surprisingly complex immune system in which the moderately sized sets of pattern recognition receptors that form the core of vertebrate innate immunity are encoded in large multigene families. The sea urchin genome contains 253 Toll-like receptor (TLR genes, more than 200 Nod-like receptors and 1095 scavenger receptor cysteine-rich domains, a ten-fold expansion relative to vertebrates. Given their stereotypic structure and simple intron-exon architecture, the TLRs are the most tractable of these families for more detailed analysis. An immune defense role for these receptors is suggested by their sequence diversity and expression in immunologically active tissues, including phagocytes. This complexity of the sea urchin TLR multigene families largely derives from expansions that are independent of those in vertebrates and protostomes, although a small family of TLRs with structure similar to that of Drosophila Toll likely originated in an ancient eumetazoan ancestor. Several other invertebrate deuterostome genomes have been sequenced, including the cephalochordate, Branchiostoma floridae and the sea urchin Lytechinus variegatus, as well as partial sequences from two other sea urchin species. Here, we present an analysis of the invertebrate deuterostome TLRs with emphasis on the echinoderms. Representatives of most of the S. purpuratus TLR subfamilies and homologs of the protostome-like sequences are found in L. variegatus. The phylogeny of these genes within sea urchins highlights lineage-specific expansions at higher resolution than is evident at the phylum level. These analyses identify quickly evolving TLR subfamilies that are likely to have novel functions and other, more stable, subfamilies that may function similarly to those of vertebrates.

  8. Transcriptomic responses to ocean acidification in larval sea urchins from a naturally variable pH environment.

    Science.gov (United States)

    Evans, Tyler G; Chan, Francis; Menge, Bruce A; Hofmann, Gretchen E

    2013-03-01

    Some marine ecosystems already experience natural declines in pH approximating those predicted with future anthropogenic ocean acidification (OA), the decline in seawater pH caused by the absorption of atmospheric CO2 . The molecular mechanisms that allow organisms to inhabit these low pH environments, particularly those building calcium carbonate skeletons, are unknown. Also uncertain is whether an enhanced capacity to cope with present day pH variation will confer resistance to future OA. To address these issues, we monitored natural pH dynamics within an intertidal habitat in the Northeast Pacific, demonstrating that upwelling exposes resident species to pH regimes not predicted to occur elsewhere until 2100. Next, we cultured the progeny of adult purple sea urchins (Strongylocentrotus purpuratus) collected from this region in CO2 -acidified seawater representing present day and near future ocean scenarios and monitored gene expression using transcriptomics. We hypothesized that persistent exposure to upwelling during evolutionary history will have selected for increased pH tolerance in this population and that their transcriptomic response to low pH seawater would provide insight into mechanisms underlying pH tolerance in a calcifying species. Resulting expression patterns revealed two important trends. Firstly, S. purpuratus larvae may alter the bioavailability of calcium and adjust skeletogenic pathways to sustain calcification in a low pH ocean. Secondly, larvae use different strategies for coping with different magnitudes of pH stress: initiating a robust transcriptional response to present day pH regimes but a muted response to near future conditions. Thus, an enhanced capacity to cope with present day pH variation may not translate into success in future oceans. © 2013 Blackwell Publishing Ltd.

  9. Dynamic evolution of toll-like receptor multigene families in echinoderms.

    Science.gov (United States)

    Buckley, Katherine M; Rast, Jonathan P

    2012-01-01

    The genome sequence of the purple sea urchin, Strongylocentrotus purpuratus, a large and long-lived invertebrate, provides a new perspective on animal immunity. Analysis of this genome uncovered a highly complex immune system in which the gene families that encode homologs of the pattern recognition receptors that form the core of vertebrate innate immunity are encoded in large multigene families. The sea urchin genome contains 253 Toll-like receptor (TLR) sequences, more than 200 Nod-like receptors and 1095 scavenger receptor cysteine-rich domains, a 10-fold expansion relative to vertebrates. Given their stereotypic protein structure and simple intron-exon architecture, the TLRs are the most tractable of these families for more detailed analysis. A role for these receptors in immune defense is suggested by their similarity to TLRs in other organisms, sequence diversity, and expression in immunologically active tissues, including phagocytes. The complexity of the sea urchin TLR multigene families is largely derived from expansions independent of those in vertebrates and protostomes, although a small family of TLRs with structure similar to that of Drosophila Toll can be traced to an ancient eumetazoan ancestor. Several other echinoderm sequences are now available, including Lytechinus variegatus, as well as partial sequences from two other sea urchin species. Here, we present an analysis of the invertebrate deuterostome TLRs with emphasis on the echinoderms. Representatives of most of the S. purpuratus TLR subfamilies and homologs of the mccTLR sequences are found in L. variegatus, although the L. variegatus TLR gene family is notably smaller (68 TLR sequences). The phylogeny of these genes within sea urchins highlights lineage-specific expansions at higher resolution than is evident at the phylum level. These analyses identify quickly evolving TLR subfamilies that are likely to have novel immune recognition functions and other, more stable, subfamilies that may

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

    Energy Technology Data Exchange (ETDEWEB)

    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. SoxB2

    Science.gov (United States)

    Anishchenko, Evgeniya; Arnone, Maria Ina; D'Aniello, Salvatore

    2018-01-01

    Current studies in evolutionary developmental biology are focused on the reconstruction of gene regulatory networks in target animal species. From decades, the scientific interest on genetic mechanisms orchestrating embryos development has been increasing in consequence to the fact that common features shared by evolutionarily distant phyla are being clarified. In 2011, a study across eumetazoan species showed for the first time the existence of a highly conserved non-coding element controlling the SoxB2 gene, which is involved in the early specification of the nervous system. This discovery raised several questions about SoxB2 function and regulation in deuterostomes from an evolutionary point of view. Due to the relevant phylogenetic position within deuterostomes, the sea urchin Strongylocentrotus purpuratus represents an advantageous animal model in the field of evolutionary developmental biology. Herein, we show a comprehensive study of SoxB2 functions in sea urchins, in particular its expression pattern in a wide range of developmental stages, and its co-localization with other neurogenic markers, as SoxB1 , SoxC and Elav . Moreover, this work provides a detailed description of the phenotype of sea urchin SoxB2 knocked-down embryos, confirming its key function in neurogenesis and revealing, for the first time, its additional roles in oral and aboral ectoderm cilia and skeletal rod morphology. We concluded that SoxB2 in sea urchins has a neurogenic function; however, this gene could have multiple roles in sea urchin embryogenesis, expanding its expression in non-neurogenic cells. We showed that SoxB2 is functionally conserved among deuterostomes and suggested that in S. purpuratus this gene acquired additional functions, being involved in ciliogenesis and skeletal patterning.

  12. SoxB2 in sea urchin development: implications in neurogenesis, ciliogenesis and skeletal patterning

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    Evgeniya Anishchenko

    2018-02-01

    Full Text Available Abstract Background Current studies in evolutionary developmental biology are focused on the reconstruction of gene regulatory networks in target animal species. From decades, the scientific interest on genetic mechanisms orchestrating embryos development has been increasing in consequence to the fact that common features shared by evolutionarily distant phyla are being clarified. In 2011, a study across eumetazoan species showed for the first time the existence of a highly conserved non-coding element controlling the SoxB2 gene, which is involved in the early specification of the nervous system. This discovery raised several questions about SoxB2 function and regulation in deuterostomes from an evolutionary point of view. Results Due to the relevant phylogenetic position within deuterostomes, the sea urchin Strongylocentrotus purpuratus represents an advantageous animal model in the field of evolutionary developmental biology. Herein, we show a comprehensive study of SoxB2 functions in sea urchins, in particular its expression pattern in a wide range of developmental stages, and its co-localization with other neurogenic markers, as SoxB1, SoxC and Elav. Moreover, this work provides a detailed description of the phenotype of sea urchin SoxB2 knocked-down embryos, confirming its key function in neurogenesis and revealing, for the first time, its additional roles in oral and aboral ectoderm cilia and skeletal rod morphology. Conclusions We concluded that SoxB2 in sea urchins has a neurogenic function; however, this gene could have multiple roles in sea urchin embryogenesis, expanding its expression in non-neurogenic cells. We showed that SoxB2 is functionally conserved among deuterostomes and suggested that in S. purpuratus this gene acquired additional functions, being involved in ciliogenesis and skeletal patterning.

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

    Science.gov (United States)

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

    2016-03-16

    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. © 2016 The Authors.

  14. Diversidad y abundancia de moluscos de la epifauna en la comunidad sublitoral de Punta Patilla,Venezuela

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    Antulio Prieto A

    2005-06-01

    Full Text Available Se estudió la diversidad de una comunidad malacológica sublitoral en Punta Patilla, Estado Sucre, Venezuela, desde septiembre 1990 hasta septiembre 1991. Se identificaron 25 especies, 14 bivalvos y 11 gasterópodos. Los parámetros de diversidad total en número de la comunidad fueron H´=3.41 bits/ind., J´=0.74 y 1-D =0.85. Las máximas diversidades mensuales se observaron en marzo 1991 (3.12 bits/ind., junio 1991 (2.88 bits/ind y septiembre 1991 (2.95 bits/ind. y la mínima ocurrió en agosto 1991 (1.20 bits/ind.. Los datos del número de individuos conforman una línea recta ajustada por la serie logarítmica con un índice alfa =4.56 y alfa =3.11 para los de biomasa. Las especies más abundantes fueron Chione cancellata, Antigona listeri, Chione granulata y Arca zebra entre los bivalvos, y Chicoreus brevifrons, Turritella variegata y Phyllonotus pomum entre los gasterópodos, estos presentaron las máximas biomasas individuales. La biomasa total promedio de la comunidad (56.80 g/m² es baja cuando se compara con otros reportes de áreas tropicales. Los moluscos habitaron fondos de grava y arenofangoso cubiertos por praderas de Thalasia testudinumDiversity and abundance of mollusks in the sublittoral epifaunal community of Punta Patilla, Venezuela. The diversity of a sublittoral epifaunal mollusk community of Punta Patilla, Sucre State, Venezuela, was studied from September 1990 to September 1991. We identified 25 species (14 bivalves and 11 gastropods of mollusks that inhabit gravel, soft sand and bottoms covered by Thalassia testudinum.Total diversity indices were H´= 3.42, J´= 0.74 and 1-D = 0.85. Monthly diversity reached its maximum in March 1991 (3.12 bits/ ind., June 1991 (2.88 bits/ind. and September 1991 (2.95 bits/ind.; minimum diversity was recorded in August 1991 (1.20 bits/ind..A log series model showed a diversity index alpha = 4.56 for species abundance data and alpha = 3.11 for biomass data. The more abundant species were

  15. Heavy metals in the rock oyster Crassostrea iridescens (Filibranchia: Ostreidae from Mazatlan, Sinaloa, Mexico

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    Martín G Frías-Espericueta

    1999-12-01

    Full Text Available Two populations of Crassostrea iridescens were sampled off Mazatlan and in a zone free of anthropogenic activity. The bivalves were collected from February 1992 to February 1993. Concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn were determined by flame atomic absorption spectrophotometry. Annual mean values in the sampling zone off Mazatlan were higher in Co, Cu, Fe, Mn, Ni and Zn than in the sampling zone free of anthropogenic activity; however, differences were not statistically significant at 95% confidence level. Urban discharges in the coastal zone in front of Mazatlan city, have little or no heavy metal concentrations dissolved or particulated.Dos poblaciones de Crassostrea iridescens fueron muestreadas en la zona costera de la ciudad de Mazatlan y en una zona libre de actividad antropogénica. Los bivalvos fueron colectados de febrero de 1992 a febrero de 1993. Concentraciones de Cd, Co, Cr, Cu, Fe, Mn, Ni y Zn fueron determinados por espectrofotometría de absorción atómica. Los valores medios anuales en la estación de muestreo de la ciudad de Mazatlán fueron mayores en Co, Cu, Fe, Mn, Ni y Zn que los determinados en la zona libre de actividad antropogénica; sin embargo, las diferencias no fueron significativas al nivel de confianza del 95%. Una conclusión es que las descargas urbanas en la zona costera en frente de Mazatlán no tiene, o tiene, bajas concentraciones de metales pesados disueltos o particulados.

  16. REDESCRIPCIÓN DE POTAMOLITHUS SUPERSULCATUS PILSBRY, 1896 (GASTROPODA, TATEIDAE DEL SUR DE LA CUENCA DEL PLATA

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    MICAELA DE LUCÍA

    Full Text Available RESUMEN El género Potamolithus Pilsbry, 1896 (Gastropoda; Tateidae, posee 31 especies, 22 de las cuales se hayan en la Argentina distribuidas principalmente en la cuenca Del Plata, definiendo al río Uruguay y al Río de la Plata como una zona caliente de diversidad en gasterópodos dulceacuícolas. Sin embargo, la mayoría de sus especies han sido descriptas solo por caracteres conquilógicos y, unas pocas tienen datos anatómicos, conllevando a la descripción de subespecies o morfos que se superponen unos a otros. A Potamolithus lapidum algunos autores le atribuyen cuatro subespecies (con datos conquiológicos, y una con datos parciales de anatomía blanda, sin embargo otros incluyen ocho “morfos”. Aquí nosotros damos un comienzo en el estudio de Potamolithus lapidum elevando a Potamolithus lapidum supersulcatus Pilsbry, 1896 a la categoría de especie, de la cual solo se conocen caracteres conquiológicos y radulares parcialmente. Aportamos datos de: concha, órganos paleales, cabeza, pie, pene, rádula, sistemas reproductor femenino y masculino, sistema nervioso y, secuencia parcial del gen mitocondrial citocromo c oxidasa subunidad I. Es necesario realizar una buena descripción de las especies del género Potamolithus debido a que algunas de las especies ya han sido citadas como especies vulnerables y que habitan ríos que están siendo modificados por la actividad humana y por la presencia del bivalvo invasor Limnoperna fortunei.

  17. Paleoenvironmental interpretation of late Quaternary molluscan assemblages from southern South América: A taphonomic comparison between the Strait of Magellan and the Beagle Channel Interpretación paleoambiental de ensambles de moluscos del Cuaternario tardío del sur de América del Sur: una comparación tafonómica entre el Estrecho de Magallanes y el Canal Beagle

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    Javiera Cárdenas

    2009-01-01

    Full Text Available This study analyzes the Holocene molluscan assemblage in raised marine terraces along the coasts of the Strait of Magellan and the Beagle Channel. A total of 33 gastropods and 12 bivalves were identified. They constitute the first mollusk listing for deposits in the Strait of Magellan. Taphonomic analysis suggests a high energy environment with epifaunal elements in the Strait of Magellan and a low energy environment with the predominance of infaunal elements in the Beagle Channel. All the collected species are living taxa suggesting that postglacial climatic variations were not enough to alter the composition of the communities since at least 6,000 yr BP in the southern Chile-Argentina región.Este trabajo analiza los ensambles de moluscos del Holoceno de las terrazas marinas presentes a lo largo de las costas del Estrecho de Magallanes y del Canal Beagle. Un total de 33 especies de gastrópodos y 12 de bivalvos fueron identificados. Ellos constituyen un primer listado de moluscos para los depósitos del Estrecho de Magallanes. El análisis tafonómico sugiere un ambiente de alta energía con elementos epifaunales en el Estrecho de Magallanes y un ambiente de baja energía con el predominio de elementos infaunales para el Canal Beagle. Todas las especies colectadas son taxa vivientes, lo que sugiere que las variaciones climáticas postglaciales no fueron suficientes para alterar la composición de las comunidades desde al menos 6.000 años AP en el extremo austral de Chile-Argentina.

  18. Acondicionamiento de reproductores y caracterización gonadal de Tawera gayi (Hupé, 1854 (Bivalva: Veneridae bajo condiciones controladas de cultivo.

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    P.Trigo

    2013-12-01

    Full Text Available El presente estudio describe el acondicionamiento de reproductores bajo sistema controlado del bivalvo Tawera gayi (Hupé, 1854, en el cual se caracterizó el estado de madurez gonadal en base a la presencia de células germinales masculinas y femeninas, estableciéndose su identificación mediante histología a través de microscopia óptica. Como metodología para el acondicionamiento se empleó una bandeja de 15,31 L de volumen útil donde fueron mantenidos 100 ejemplares de T. gayi. El sistema se mantuvo con agua de mar a 29-30 ppm con recambio de agua cada 3 días a temperatura promedio de 16 -18 °C. Con alimentación continua de una mezcla de microalgas de Isochrysis galbana y Chaetoceros muelleri. Los resultados obtenidos, ponen en manifiesto que T. gayi es una especie dioica, sin dimorfismo sexual. Presenta fecundación externa, con un ciclo reproductivo continuo, asincrónico y sin reposo gonadal. Durante las primeras semanas de aclimatación los machos presentaron 100 % de madurez máxima, mientras que las hembras demostraron un 71 % de madurez avanzada y 29% de madurez máxima. Una vez acondicionadas y con alimento continuo, se logró 100% de evacuación parcial en hembras y 50% de evacuación parcial y total en machos, obteniendo desove en cautiverio.

  19. Centrocestus formosanus (Opisthorchiida: Heterophyidae como causa de muerte de alevines de tilapia gris Oreochromis niloticus (Perciforme: Cichlidae en el Pacífico seco de Costa Rica

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    Donald Arguedas Cortés

    2010-12-01

    Full Text Available Centrocestus formosanus es un parásito trematodo zoonótico originario de Asia asociado con muertes de peces principalmente de cultivo. 907 moluscos provenientes de estanques sembrados con tilapias, seleccionados uno por provincia fueron identificados al nivel taxonómico especifico. Se identificaron cuatro gastrópodos y un bivalvo: M. tuberculata, M. turricula, P. flagellata, H. cubensis y A. luteola. Se reporta, por primera vez, la presencia de dos especies de moluscos en Costa Rica. Se identificaron siete morfotipos de cercarias parasitando las cinco especies de moluscos encontradas. En la segunda exposición experimental se demostró que el morfotipo parapleurolofocercus encontrado en M. tuberculata concuerda con el hallazgo de C. formosanus en alevines de tilapia, después del examen clínico, anatomopatológico y parasitológico realizado a los alevines expuestos. Las metacercarias fueron extraídas del quiste utilizando microagujas y micropinzas lavadas en solución salina fisiológica (0.65%, fijadas en formol caliente al 4% y después esquematizadas con una cámara clara adaptada a un microscopio fotónico, estimándose una abundancia e intensidad media de 1018-1027 digeneos por branquia en cada pez parasitado, determinándose así el hospedador intermediario primario y secundario del parásito. En el presente trabajo se reporta por primera vez Centrocestus formosanus en Costa Rica.

  20. Cambios en el uso de la ostra perlera Pinctada mazatlanica (Bivalvia: Pteriidae en el Templo Mayor de Tenochtitlan Changes in the use of the pearl oyster Pinctada mazatlanica (Bivalvia: Pteriidae in the Great Temple of Tenochtitlan

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    Adrián Velázquez

    2007-10-01

    Full Text Available La concha del bivalvo panámico Pinctada mazatlanica fue ampliamente utilizada por las antiguas sociedades del México prehispánico; en las ofrendas enterradas en el Templo Mayor de Tenochtitlan se han encontrado alrededor de 600 objetos elaborados con ella, la mayor parte de los cuales proceden de la etapa constructiva IV (1440-1481, lo que llama la atención, ya que para entonces los mexicas no habían logrado conquistar emplazamientos en la costa del Pacífico. En los sucesivos agrandamientos arquitectónicos es notable el descenso en los objetos de la referida ostra, lo cual en principio se explicó por la mayor destrucción que éstos habían sufrido; sin embargo, el hallazgo de varios ricos depósitos en el predio conocido como Casa de las Ajaracas, correspondientes al reinado de Moctezuma II (1502-1521, en los que prácticamente se encuentra ausente la Pinctada mazatlanica, da lugar a nuevas interpretaciones. En el presente trabajo se presentan 2 posibles hipótesis para explicar el hecho anterior.The nacreous shell of the tropical Pacific mollusc Pinctada mazatlanica was widely used by the ancient inhabitants of Mexico. Around 600 pieces made of this shell have been found in offerings buried in the Great Temple of Tenochtitlan. Most of these objects come from the IVth construction stage (1440-1481, prior to the conquest of the Pacific Coast by the Aztecs. It was previously thought that the considerably smaller numbers found in the following stages were due to the greater degree of destruction suffered by the temple. Nevertheless, the almost complete absence of this material in nine offerings found recently corresponding to the VIIth construction stage (1502-1521, raise other possibilities. In this work two different hypotheses are presented to explain this observation.

  1. Metalotioninas en Perna viridis (Bivalvia: Mytilidae: variación estacional y su relación con la biología reproductiva

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    Mairin Lemus

    2013-06-01

    Full Text Available Las metalotioninas (Mts son proteínas de baja masa molecular que juegan un rol importante en la detoxificación de metales, en vista de su papel ecotoxicológico se evaluaron las metalotioneínas (MTs en 350 ejemplares del bivalvo Perna viridis en dos localidades de la costa norte del estado Sucre, desde febrero hasta diciembre 2003. Se determinaron los índices biométricos: índice de condición (IC, rendimiento de carne (RC y relación peso seco-talla (PSL. Las Mts fueron separadas por cromatografía de exclusión molecular, Sephadex G-50 y se cuantificaron por saturación con cadmio. Los índices biométricos (RC y PSL mostraron variaciones estacionales, entre localidades y estados de madurez, con la excepción del CI. No se encontraron diferencias significativas entre sexos. Las Mts mostraron variaciones estacionales, con concentraciones más elevadas entre febrero y marzo y mínimos entre septiembre y diciembre, que coincidieron con los períodos de alta y baja productividad en el área, respectivamente. Los mejillones de Río Caribe presentaron una mayor concentración de Mts que los de Chacopata. Los mejillones inmaduros mostraron la mayor concentración de Mts y la más baja en los desovados. Se encontró una relación negativa y significativa entre Mts y CI. Los resultados demuestran que las Mts de Perna viridis están influidas por el índice de condición y la condición reproductiva, asi como también pot los factores físico-químicos del ambiente marino.

  2. Paleontología y ambientes sedimentarios del Triásico medio, Muschelkalk, de la Cordillera Ibérica 1: Cuencas y Valencia. España

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    López Gómez, J.

    1989-12-01

    , constituyen la Facies Muscbelkalk al SE. de la Rama Castel1ana de la Cordil1era Ibérica. Este trabajo enfoca el estudio paleontológico y de los medios sedimentarios de las dos unidades carbonatadas (d.L. y d.c.C.. Para ello, se han utilizado 10 columnas estratigráficas a lo largo de todo el área de estudio en las cuales se han diferenciado 9 asociaciones de facies constituidas cada una por una secuencia característica de menos de 2 m. de espesor. Se ha escogido una serie tipo en la que se han diferenciado 9 tramos constituidos cada uno de el10s por la repetición de una misma secuencia de las anteriormente citadas. Del análisis de estas secuencias han sido diferenciados tres distintos subambientes para cada unidad carbonatada, siendo éstos de bajio, zona protegida poco profunda y zona supramareal «shoal», «lagoon» y «Sabkba», respectivamente dentro de una rampa somera, y dos episodios en el desarrollo del sistema deposicional, uno primero y corto transgresivo y otro segundo y mayor de carácter regresivo. Posiblemente debido a los efectos de la dolomitización, el registro fósil es en general escaso y mal conservado. El mayor contenido está constituido por moluscos de la clase Bivalvia que refleja una asociación bentónica principalmente compuesta por suspensívoros. Aunque los bivalvos son encontrados en ambas unidades carbonatadas, en la superior (d.c.C., la diversidad específica es mayor. El análisis tafonómico realizado nos permite identificar algunas asociaciones autóctonas, formadas principalmente por elementos acumulados en ambas unidades. Se define cuantitativamente la «Fauna de Teruel», como el conjunto de bivalvos característicos de las capas terminales del Muscbelkalk carbonatado más alto de la Cordillera Ibérica; para esta definición, nos basamos principalmente en los bal1azgos de las series de Villora y Henarejos. El conjunto de bivalvos está formado mayoritariamente por infaunales, seguido de endo y epibisados con una

  3. Dinámica poblacional de Donax dentifer (Veneroida: Donacidae en Bahía Málaga, Pacífico colombiano durante el fenómeno "El Niño" 1997/1998

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    José M. Riascos

    2002-12-01

    Full Text Available Donax dentifer es un bivalvo dominante en comunidades de playa arenosa en la costa del Pacífico colombiano. Se muestreó mensualmente una población de este bivalvo en Bahía Málaga, Pacífico colombiano entre agosto de 1997 y julio de 1998 cuando ocurrió el evento "El Niño" 1997/1998. Se tomaron muestras cuantitativas mensuales usando transectos lineales perpendiculares y paralelos a la línea de costa para determinar la densidad poblacional y realizar una distribución de frecuencias de longitud. Se tomaron también muestras cualitativas mensuales para estudiar la reproducción y establecer relaciones peso-longitud. Se registró la temperatura, oxígeno disuelto, salinidad y pH de la columna de agua en el sitio de muestreo. Adicionalmente se realizó un experimento de marcaje-recaptura para estimar el crecimiento de la población. Los resultados indican que la población tiene un ciclo de reproducción continuo, con dos períodos de desove anuales en diciembre y marzo. Los parámetros de crecimiento de la función de crecimiento de von Bertalanffy fueron K=0.624 año-1 y L∞=29.3 mm. La mortalidad total (Z fue de Z=2.605 año -1 para los individuos pequeños (entre 2 mm y 5 mm y menor (Z=1.714 año -1 para los individuos grandes (entre 19 mm y 25 mm. La biomasa promedio anual de la población fue =1.22 g de peso seco libre de cenizas m-2 y la producción somática anual Psom/= 1.215 g de peso seco libre de cenizas m-2, lo que corresponde a una tasa de Psom/= 0.988. Aunque se observó un incremento en la densidad poblacional durante noviembre y abril, no hay evidencia de una clara relación entre la densidad poblacional y la ocurrencia del fenómeno "El Niño". Los cambios en la concentración de oxígeno disuelto mostraron una alta correlación con los parámetros del ciclo reproductivo, posiblemente como consecuencia de la influencia de este parámetro en procesos de asimilación y el ciclo de peso corporal. El crecimiento de D. dentifer

  4. Testing lagoonal sediments with early life stages of the copepod Acartia tonsa (Dana): An approach to assess sediment toxicity in the Venice Lagoon.

    Science.gov (United States)

    Picone, Marco; Bergamin, Martina; Delaney, Eugenia; Ghirardini, Annamaria Volpi; Kusk, Kresten Ole

    2018-01-01

    The early-life stages of development of the calanoid copepod Acartia tonsa from egg to copepodite I is proposed as an endpoint for assessing sediment toxicity by exposing newly released eggs directly onto the sediment-water interface. A preliminary study of 5 sediment samples collected in the lagoon of Venice highlighted that the larval development rate (LDR) and the early-life stages (ELS) mortality endpoints with A. tonsa are more sensitive than the standard amphipod mortality test; moreover LDR resulted in a more reliable endpoint than ELS mortality, due to the interference of the sediment with the recovery of unhatched eggs and dead larvae. The LDR data collected in a definitive study of 48 sediment samples from the Venice Lagoon has been analysed together with the preliminary data to evaluate the statistical performances of the bioassay (among replicate variance and minimum significant difference between samples and control) and to investigate the possible correlation with sediment chemistry and physical properties. The results showed that statistical performances of the LDR test with A. tonsa correspond with the outcomes of other tests applied to the sediment-water interface (Strongylocentrotus purpuratus embryotoxicity test), sediments (Neanthes arenaceodentata survival and growth test) and porewater (S. purpuratus); the LDR endpoint did, however, show a slightly higher variance as compared with other tests used in the Lagoon of Venice, such as 10-d amphipod lethality test and larval development with sea urchin and bivalves embryos. Sediment toxicity data highlighted the high sensitivity and the clear ability of the larval development to discriminate among sediments characterized by different levels of contamination. The data of the definitive study evidenced that inhibition of the larval development was not affected by grain-size and the organic carbon content of the sediment; in contrast, a strong correlation between inhibition of the larval development

  5. The skeletal proteome of the sea star Patiria miniata and evolution of biomineralization in echinoderms.

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    Flores, Rachel L; Livingston, Brian T

    2017-06-05

    Proteomic studies of skeletal proteins have revealed large, complex mixtures of proteins occluded within the mineral. Many skeletal proteomes contain rapidly evolving proteins with repetitive domains, further complicating our understanding. In echinoderms, proteomic analysis of the skeletal proteomes of mineralized tissues of the sea urchin Strongylocentrotus purpuratus prominently featured spicule matrix proteins with repetitive sequences linked to a C-type lectin domain. A comparative study of the brittle star Ophiocoma wendtii skeletal proteome revealed an order of magnitude fewer proteins containing C-type lectin domains. A number of other proteins conserved in the skeletons of the two groups were identified. Here we report the complete skeletal proteome of the sea star Patiria miniata and compare it to that of the other echinoderm groups. We have identified eighty-five proteins in the P. miniata skeletal proteome. Forty-two percent of the proteins were determined to be homologous to proteins found in the S. purpuratus skeletal proteomes. An additional 34 % were from similar functional classes as proteins in the urchin proteomes. Thirteen percent of the P. miniata proteins had homologues in the O. wendtii skeletal proteome with an additional 29% showing similarity to brittle star skeletal proteins. The P. miniata skeletal proteome did not contain any proteins with C-lectin domains or with acidic repetitive regions similar to the sea urchin or brittle star spicule matrix proteins. MSP130 proteins were also not found. We did identify a number of proteins homologous between the three groups. Some of the highly conserved proteins found in echinoderm skeletons have also been identified in vertebrate skeletons. The presence of proteins conserved in the skeleton in three different echinoderm groups indicates these proteins are important in skeleton formation. That a number of these proteins are involved in skeleton formation in vertebrates suggests a common origin for

  6. Sequencing and analysis of the gastrula transcriptome of the brittle star Ophiocoma wendtii

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    Vaughn Roy

    2012-09-01

    Full Text Available Abstract Background The gastrula stage represents the point in development at which the three primary germ layers diverge. At this point the gene regulatory networks that specify the germ layers are established and the genes that define the differentiated states of the tissues have begun to be activated. These networks have been well-characterized in sea urchins, but not in other echinoderms. Embryos of the brittle star Ophiocoma wendtii share a number of developmental features with sea urchin embryos, including the ingression of mesenchyme cells that give rise to an embryonic skeleton. Notable differences are that no micromeres are formed during cleavage divisions and no pigment cells are formed during development to the pluteus larval stage. More subtle changes in timing of developmental events also occur. To explore the molecular basis for the similarities and differences between these two echinoderms, we have sequenced and characterized the gastrula transcriptome of O. wendtii. Methods Development of Ophiocoma wendtii embryos was characterized and RNA was isolated from the gastrula stage. A transcriptome data base was generated from this RNA and was analyzed using a variety of methods to identify transcripts expressed and to compare those transcripts to those expressed at the gastrula stage in other organisms. Results Using existing databases, we identified brittle star transcripts that correspond to 3,385 genes, including 1,863 genes shared with the sea urchin Strongylocentrotus purpuratus gastrula transcriptome. We characterized the functional classes of genes present in the transcriptome and compared them to those found in this sea urchin. We then examined those members of the germ-layer specific gene regulatory networks (GRNs of S. purpuratus that are expressed in the O. wendtii gastrula. Our results indicate that there is a shared ‘genetic toolkit’ central to the echinoderm gastrula, a key stage in embryonic development, though

  7. Transcriptome Analysis of the Scleractinian Coral Stylophora pistillata

    Science.gov (United States)

    Salmon-Divon, Mali; Katzenellenbogen, Mark; Tambutté, Sylvie; Bertucci, Anthony; Hoegh-Guldberg, Ove; Deleury, Emeline; Allemand, Denis; Levy, Oren

    2014-01-01

    The principal architects of coral reefs are the scleractinian corals; these species are divided in two major clades referred to as “robust” and “complex” corals. Although the molecular diversity of the “complex” clade has received considerable attention, with several expressed sequence tag (EST) libraries and a complete genome sequence having been constructed, the “robust” corals have received far less attention, despite the fact that robust corals have been prominent focal points for ecological and physiological studies. Filling this gap affords important opportunities to extend these studies and to improve our understanding of the differences between the two major clades. Here, we present an EST library from Stylophora pistillata (Esper 1797) and systematically analyze the assembled transcripts compared to putative homologs from the complete proteomes of six well-characterized metazoans: Nematostella vectensis, Hydra magnipapillata, Caenorhabditis elegans, Drosophila melanogaster, Strongylocentrotus purpuratus, Ciona intestinalis and Homo sapiens. Furthermore, comparative analyses of the Stylophora pistillata ESTs were performed against several Cnidaria from the Scleractinia, Actiniaria and Hydrozoa, as well as against other stony corals separately. Functional characterization of S. pistillata transcripts into KOG/COG categories and further description of Wnt and bone morphogenetic protein (BMP) signaling pathways showed that the assembled EST library provides sufficient data and coverage. These features of this new library suggest considerable opportunities for extending our understanding of the molecular and physiological behavior of “robust” corals. PMID:24551124

  8. Patterns of Mass Mortality among Rocky Shore Invertebrates across 100 km of Northeastern Pacific Coastline.

    Directory of Open Access Journals (Sweden)

    Laura J Jurgens

    Full Text Available Mass mortalities in natural populations, particularly those that leave few survivors over large spatial areas, may cause long-term ecological perturbations. Yet mass mortalities may remain undocumented or poorly described due to challenges in responding rapidly to unforeseen events, scarcity of baseline data, and difficulties in quantifying rare or patchily distributed species, especially in remote or marine systems. Better chronicling the geographic pattern and intensity of mass mortalities is especially critical in the face of global changes predicted to alter regional disturbance regimes. Here, we couple replicated post-mortality surveys with preceding long-term surveys and historical data to describe a rapid and severe mass mortality of rocky shore invertebrates along the north-central California coast of the northeastern Pacific Ocean. In late August 2011, formerly abundant intertidal populations of the purple sea urchin (Strongylocentrotus purpuratus, a well-known ecosystem engineer, and the predatory six-armed sea star (Leptasterias sp. were functionally extirpated from ~100 km of coastline. Other invertebrates, including the gumboot chiton (Cryptochiton stelleri the ochre sea star (Pisaster ochraceus, and subtidal populations of purple sea urchins also exhibited elevated mortality. The pattern and extent of mortality suggest the potential for long-term population, community, and ecosystem consequences, recovery from which may depend on the different dispersal abilities of the affected species.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Transcriptome analysis of the scleractinian coral Stylophora pistillata.

    Directory of Open Access Journals (Sweden)

    Sarit Karako-Lampert

    Full Text Available The principal architects of coral reefs are the scleractinian corals; these species are divided in two major clades referred to as "robust" and "complex" corals. Although the molecular diversity of the "complex" clade has received considerable attention, with several expressed sequence tag (EST libraries and a complete genome sequence having been constructed, the "robust" corals have received far less attention, despite the fact that robust corals have been prominent focal points for ecological and physiological studies. Filling this gap affords important opportunities to extend these studies and to improve our understanding of the differences between the two major clades. Here, we present an EST library from Stylophora pistillata (Esper 1797 and systematically analyze the assembled transcripts compared to putative homologs from the complete proteomes of six well-characterized metazoans: Nematostella vectensis, Hydra magnipapillata, Caenorhabditis elegans, Drosophila melanogaster, Strongylocentrotus purpuratus, Ciona intestinalis and Homo sapiens. Furthermore, comparative analyses of the Stylophora pistillata ESTs were performed against several Cnidaria from the Scleractinia, Actiniaria and Hydrozoa, as well as against other stony corals separately. Functional characterization of S. pistillata transcripts into KOG/COG categories and further description of Wnt and bone morphogenetic protein (BMP signaling pathways showed that the assembled EST library provides sufficient data and coverage. These features of this new library suggest considerable opportunities for extending our understanding of the molecular and physiological behavior of "robust" corals.

  11. Selective accumulation of germ-line associated gene products in early development of the sea star and distinct differences from germ-line development in the sea urchin.

    Science.gov (United States)

    Fresques, Tara; Zazueta-Novoa, Vanesa; Reich, Adrian; Wessel, Gary M

    2014-04-01

    Echinodermata is a diverse phylum, a sister group to chordates, and contains diverse organisms that may be useful to understand varied mechanisms of germ-line specification. We tested 23 genes in development of the sea star Patiria miniata that fall into five categories: (1) Conserved germ-line factors; (2) Genes involved in the inductive mechanism of germ-line specification; (3) Germ-line associated genes; (4) Molecules involved in left-right asymmetry; and (5) Genes involved in regulation and maintenance of the genome during early embryogenesis. Overall, our results support the contention that the posterior enterocoel is a source of the germ line in the sea star P. miniata. The germ line in this organism appears to be specified late in embryogenesis, and in a pattern more consistent with inductive interactions amongst cells. This is distinct from the mechanism seen in sea urchins, a close relative of the sea star clad. We propose that P. miniata may serve as a valuable model to study inductive mechanisms of germ-cell specification and when compared with germ-line formation in the sea urchin S. purpuratus may reveal developmental transitions that occur in the evolution of inherited and inductive mechanisms of germ-line specification. Copyright © 2013 Wiley Periodicals, Inc.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Macroarray analysis of coelomocyte gene expression in response to LPS in the sea urchin. Identification of unexpected immune diversity in an invertebrate.

    Science.gov (United States)

    Nair, Sham V; Del Valle, Heather; Gross, Paul S; Terwilliger, David P; Smith, L Courtney

    2005-06-16

    The purple sea urchin, Strongylocentrotus purpuratus, is a member of the phylum Echinodermata, which is basal to the phylum Chordata within the deuterostome lineage of the animal kingdom. This relationship makes the analysis of the sea urchin immune system relevant to understanding the evolution of the deuterostome immune system leading to the Vertebrata. Subtractive suppression hybridization was employed to generate cDNA probes for screening high-density arrayed, conventional cDNA libraries to identify genes that were upregulated in coelomocytes responding to lipopolysaccharide. Results from 1,247 expressed sequence tags (ESTs) were used to infer that coelomocytes upregulated genes involved in RNA splicing, protein processing and targeting, secretion, endosomal activities, cell signaling, and alterations to the cytoskeletal architecture including interactions with the extracellular matrix. Of particular note was a set of transcripts represented by 60% of the ESTs analyzed, which encoded a previously uncharacterized family of closely related proteins, provisionally designated as 185/333. These transcripts exhibited a significant level of variation in their nucleotide sequence and evidence of putative alternative splicing that could yield up to 15 translatable elements. On the basis of the striking increase in gene expression in response to lipopolysaccharide and the unexpected level of diversity of the 185/333 messages, we propose that this set of transcripts encodes a family of putative immune response proteins that may represent a major component of an immunological response to bacterial challenge.

  14. Deadenylase depletion protects inherited mRNAs in primordial germ cells.

    Science.gov (United States)

    Swartz, S Zachary; Reich, Adrian M; Oulhen, Nathalie; Raz, Tal; Milos, Patrice M; Campanale, Joseph P; Hamdoun, Amro; Wessel, Gary M

    2014-08-01

    A crucial event in animal development is the specification of primordial germ cells (PGCs), which become the stem cells that create sperm and eggs. How PGCs are created provides a valuable paradigm for understanding stem cells in general. We find that the PGCs of the sea urchin Strongylocentrotus purpuratus exhibit broad transcriptional repression, yet enrichment for a set of inherited mRNAs. Enrichment of several germline determinants in the PGCs requires the RNA-binding protein Nanos to target the transcript that encodes CNOT6, a deadenylase, for degradation in the PGCs, thereby creating a stable environment for RNA. Misexpression of CNOT6 in the PGCs results in their failure to retain Seawi transcripts and Vasa protein. Conversely, broad knockdown of CNOT6 expands the domain of Seawi RNA as well as exogenous reporters. Thus, Nanos-dependent spatially restricted CNOT6 differential expression is used to selectively localize germline RNAs to the PGCs. Our findings support a 'time capsule' model of germline determination, whereby the PGCs are insulated from differentiation by retaining the molecular characteristics of the totipotent egg and early embryo. © 2014. Published by The Company of Biologists Ltd.

  15. Transient translational quiescence in primordial germ cells.

    Science.gov (United States)

    Oulhen, Nathalie; Swartz, S Zachary; Laird, Jessica; Mascaro, Alexandra; Wessel, Gary M

    2017-04-01

    Stem cells in animals often exhibit a slow cell cycle and/or low transcriptional activity referred to as quiescence. Here, we report that the translational activity in the primordial germ cells (PGCs) of the sea urchin embryo ( Strongylocentrotus purpuratus ) is quiescent. We measured new protein synthesis with O-propargyl-puromycin and L-homopropargylglycine Click-iT technologies, and determined that these cells synthesize protein at only 6% the level of their adjacent somatic cells. Knockdown of translation of the RNA-binding protein Nanos2 by morpholino antisense oligonucleotides, or knockout of the Nanos2 gene by CRISPR/Cas9 resulted in a significant, but partial, increase (47%) in general translation specifically in the PGCs. We found that the mRNA of the translation factor eEF1A is excluded from the PGCs in a Nanos2-dependent manner, a consequence of a Nanos/Pumilio response element (PRE) in its 3'UTR. In addition to eEF1A, the cytoplasmic pH of the PGCs appears to repress translation and simply increasing the pH also significantly restores translation selectively in the PGCs. We conclude that the PGCs of this sea urchin institute parallel pathways to quiesce translation thoroughly but transiently. © 2017. Published by The Company of Biologists Ltd.

  16. SM30 protein function during sea urchin larval spicule formation.

    Science.gov (United States)

    Wilt, Fred; Killian, Christopher E; Croker, Lindsay; Hamilton, Patricia

    2013-08-01

    A central issue in better understanding the process of biomineralization is to elucidate the function of occluded matrix proteins present in mineralized tissues. A potent approach to addressing this issue utilizes specific inhibitors of expression of known genes. Application of antisense oligonucleotides that specifically suppress translation of a given mRNA are capable of causing aberrant biomineralization, thereby revealing, at least in part, a likely function of the protein and gene under investigation. We have applied this approach to study the possible function(s) of the SM30 family of proteins, which are found in spicules, teeth, spines, and tests of Strongylocentrotus purpuratus as well as other euechinoid sea urchins. It is possible using the anti-SM30 morpholino-oligonucleotides (MO's) to reduce the level of these proteins to very low levels, yet the development of skeletal spicules in the embryo shows little or no aberration. This surprising result requires re-thinking about the role of these, and possibly other occluded matrix proteins. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Transcriptome analysis of the scleractinian coral Stylophora pistillata.

    Science.gov (United States)

    Karako-Lampert, Sarit; Zoccola, Didier; Salmon-Divon, Mali; Katzenellenbogen, Mark; Tambutté, Sylvie; Bertucci, Anthony; Hoegh-Guldberg, Ove; Deleury, Emeline; Allemand, Denis; Levy, Oren

    2014-01-01

    The principal architects of coral reefs are the scleractinian corals; these species are divided in two major clades referred to as "robust" and "complex" corals. Although the molecular diversity of the "complex" clade has received considerable attention, with several expressed sequence tag (EST) libraries and a complete genome sequence having been constructed, the "robust" corals have received far less attention, despite the fact that robust corals have been prominent focal points for ecological and physiological studies. Filling this gap affords important opportunities to extend these studies and to improve our understanding of the differences between the two major clades. Here, we present an EST library from Stylophora pistillata (Esper 1797) and systematically analyze the assembled transcripts compared to putative homologs from the complete proteomes of six well-characterized metazoans: Nematostella vectensis, Hydra magnipapillata, Caenorhabditis elegans, Drosophila melanogaster, Strongylocentrotus purpuratus, Ciona intestinalis and Homo sapiens. Furthermore, comparative analyses of the Stylophora pistillata ESTs were performed against several Cnidaria from the Scleractinia, Actiniaria and Hydrozoa, as well as against other stony corals separately. Functional characterization of S. pistillata transcripts into KOG/COG categories and further description of Wnt and bone morphogenetic protein (BMP) signaling pathways showed that the assembled EST library provides sufficient data and coverage. These features of this new library suggest considerable opportunities for extending our understanding of the molecular and physiological behavior of "robust" corals.

  18. Identification and comparative analysis of complement C3-associated microRNAs in immune response of Apostichopus japonicus by high-throughput sequencing.

    Science.gov (United States)

    Zhong, Lei; Zhang, Feng; Zhai, Yu; Cao, Yanhui; Zhang, Si; Chang, Yaqing

    2015-12-04

    MicroRNAs (miRNAs) are important effectors in mediating host-pathogen interaction. In this report, coelomocytes miRNA libraries of three Japanese sea cucumbers Apostichopus japonicus were built by Illumina(®) Hiseq2000 from different time points after lipopolysaccharide challenge (at time 0 h, 6 h and 12 h). The clean data received from high throughput sequencing were used to sequences analysis. Referenced to the Strongylocentrotus purpuratus genome, 38 conserved miRNAs were found, and three miRNA candidates were predicted by software. According to the evidence resulting from the expression of AjC3, expressing levels of spu-miR-133, spu-miR-137 and spu-miR-2004 altered along with the expression of AjC3 changing at different time points after LPS injection. Thus, we speculated that the three miRNAs may have influence on A. japonicus complement C3. The spu-miR-137 and miR-137 gene family in miRBase were analyzed by bioinformatics. There is an obvious discrepancy between invertebrates and vertebrates. The first and ninth nucleotides in invertebrate miR-137 are offset compared vertebrate miR-137. Importantly, this is the first attempt to map the stage of immune response regulome in echinoderms, which might be considered as information for elucidating the intrinsic mechanism underlying the immune system in this species.

  19. Breaking out of the comfort zone: El Niño-Southern Oscillation as a driver of trophic flows in a benthic consumer of the Humboldt Current ecosystem.

    Science.gov (United States)

    Riascos, José M; Solís, Marco A; Pacheco, Aldo S; Ballesteros, Manuel

    2017-06-28

    The trophic flow of a species is considered a characteristic trait reflecting its trophic position and function in the ecosystem and its interaction with the environment. However, climate patterns are changing and we ignore how patterns of trophic flow are being affected. In the Humboldt Current ecosystem, arguably one of the most productive marine systems, El Niño-Southern Oscillation is the main source of interannual and longer-term variability. To assess the effect of this variability on trophic flow we built a 16-year series of mass-specific somatic production rate (P/B) of the Peruvian scallop ( Argopecten purpuratus ), a species belonging to a former tropical fauna that thrived in this cold ecosystem. A strong increase of the P/B ratio of this species was observed during nutrient-poor, warmer water conditions typical of El Niño, owing to the massive recruitment of fast-growing juvenile scallops. Trophic ecology theory predicts that when primary production is nutrient limited, the trophic flow of organisms occupying low trophic levels should be constrained (bottom-up control). For former tropical fauna thriving in cold, productive upwelling coastal zones, a short time of low food conditions but warm waters during El Niño could be sufficient to waken their ancestral biological features and display massive proliferations. © 2017 The Author(s).

  20. Exploring the Sea Urchin Neuropeptide Landscape by Mass Spectrometry

    Science.gov (United States)

    Monroe, Eric B.; Annangudi, Suresh P.; Wadhams, Andinet A.; Richmond, Timothy A.; Yang, Ning; Southey, Bruce R.; Romanova, Elena V.; Schoofs, Liliane; Baggerman, Geert; Sweedler, Jonathan V.

    2018-04-01

    Neuropeptides are essential cell-to-cell signaling messengers and serve important regulatory roles in animals. Although remarkable progress has been made in peptide identification across the Metazoa, for some phyla such as Echinodermata, limited neuropeptides are known and even fewer have been verified on the protein level. We employed peptidomic approaches using bioinformatics and mass spectrometry (MS) to experimentally confirm 23 prohormones and to characterize a new prohormone in nervous system tissue from Strongylocentrotus purpuratus, the purple sea urchin. Ninety-three distinct peptides from known and novel prohormones were detected with MS from extracts of the radial nerves, many of which are reported or experimentally confirmed here for the first time, representing a large-scale study of neuropeptides from the phylum Echinodermata. Many of the identified peptides and their precursor proteins have low homology to known prohormones from other species/phyla and are unique to the sea urchin. By pairing bioinformatics with MS, the capacity to characterize novel peptides and annotate prohormone genes is enhanced. [Figure not available: see fulltext.

  1. PRODUCCIÓN DE ENZIMAS EXTRACELLARES POR BACTERIAS AISLADAS DE INVERTEBRADOS MARINOS

    Directory of Open Access Journals (Sweden)

    Jorge León

    2014-06-01

    Full Text Available Con el fin de seleccionar las bacterias marinas con la capacidad de producir enzimas extracelulares ( CEE , se analizaron muestras de Argopecten purpuratus y Crassostrea gigas en el cultivo , así como de otros invertebrados interticlal y bentónicos. La selección de cepas de la CEE de productores se llevó a cabo en Agar Marino ( MA con la adición del sustrato relevante ( almidón , caseína , Tween - 80 , lecitina , ADN y gelatina . La CEE evaluación cepas productoras se llevó a cabo en 102 aislamientos . Los resultados muestran que las bacterias asociadas TOA . purpuratusand C. gigashave las mejores actividades multienzimáticos ; Sin embargo , Semimytilus algosus, Tetrapigus niger y Thais chocolata también son fuentes importantes de productores de bacterias de la CEE. La actividad multienzimático cualitativa en MA ( zonas claras u opacas alrededor de las colonias en mm de diámetro varió de 6 a > 16 mm . La frecuencia de la producción multienzimático fue caseinase 62,74 % , entre esterasa 57,84 % , 52,94 % de la amilasa , la gelatinasa 38,23 % , 33,3 % DNAsa , agarasa 5,43 % y 90,0 % lecitinasa . Los resultados sugieren la posibilidad de usar cepas nativas para fines biotecnológicos

  2. Asymmetric distribution of hypoxia-inducible factor α regulates dorsoventral axis establishment in the early sea urchin embryo.

    Science.gov (United States)

    Chang, Wei-Lun; Chang, Yi-Cheng; Lin, Kuan-Ting; Li, Han-Ru; Pai, Chih-Yu; Chen, Jen-Hao; Su, Yi-Hsien

    2017-08-15

    Hypoxia signaling is an ancient pathway by which animals can respond to low oxygen. Malfunction of this pathway disturbs hypoxic acclimation and can result in various diseases, including cancers. The role of hypoxia signaling in early embryogenesis remains unclear. Here, we show that in the blastula of the sea urchin Strongylocentrotus purpuratus , hypoxia-inducible factor α (HIFα), the downstream transcription factor of the hypoxia pathway, is localized and transcriptionally active on the future dorsal side. This asymmetric distribution is attributable to its oxygen-sensing ability. Manipulations of the HIFα level entrained the dorsoventral axis, as the side with the higher level of HIFα tends to develop into the dorsal side. Gene expression analyses revealed that HIFα restricts the expression of nodal to the ventral side and activates several genes encoding transcription factors on the dorsal side. We also observed that intrinsic hypoxic signals in the early embryos formed a gradient, which was disrupted under hypoxic conditions. Our results reveal an unprecedented role of the hypoxia pathway in animal development. © 2017. Published by The Company of Biologists Ltd.

  3. Spatial expression of Hox cluster genes in the ontogeny of a sea urchin

    Science.gov (United States)

    Arenas-Mena, C.; Cameron, A. R.; Davidson, E. H.

    2000-01-01

    The Hox cluster of the sea urchin Strongylocentrous purpuratus contains ten genes in a 500 kb span of the genome. Only two of these genes are expressed during embryogenesis, while all of eight genes tested are expressed during development of the adult body plan in the larval stage. We report the spatial expression during larval development of the five 'posterior' genes of the cluster: SpHox7, SpHox8, SpHox9/10, SpHox11/13a and SpHox11/13b. The five genes exhibit a dynamic, largely mesodermal program of expression. Only SpHox7 displays extensive expression within the pentameral rudiment itself. A spatially sequential and colinear arrangement of expression domains is found in the somatocoels, the paired posterior mesodermal structures that will become the adult perivisceral coeloms. No such sequential expression pattern is observed in endodermal, epidermal or neural tissues of either the larva or the presumptive juvenile sea urchin. The spatial expression patterns of the Hox genes illuminate the evolutionary process by which the pentameral echinoderm body plan emerged from a bilateral ancestor.

  4. Expression pattern of vascular endothelial growth factor 2 during sea urchin development.

    Science.gov (United States)

    Kipryushina, Yulia O; Yakovlev, Konstantin V; Kulakova, Milana A; Odintsova, Nelly A

    2013-12-01

    The VEGF family in the sea urchin is comprised of three members designated Vegf1 through Vegf3. In this study, we found a high level of similarity between the PDGF/VEGF domain of the predicted gene Sp-Vegf2 in the sea urchin Strongylocentrotus purpuratus and the same domain of a gene that we found in a closely related sea urchin, Strongylocentrotus intermedius. The sequence of the Si-Vegf2 cDNA was determined, and the expression of the Si-Vegf2 mRNA throughout early sea urchin development was studied by RT-PCR and in situ hybridization. Also we analyzed phylogenetic relationships of Si-Vegf2 and other members of the PDGF and VEGF families. We have found that the Si-Vegf2 present during the time span from the egg to the 4-arm pluteus stage. This mRNA is uniformly distributed in eggs, cleaving embryos and early blastulae. At the gastrula stage, the Si-Vegf2 transcripts are localized in the ventrolateral clusters of primary mesenchyme cells, and later, at the prism stage, they are detected in the forming apex. At the early pluteus stage, Si-Vegf2 mRNAs are found in two groups of mesenchyme cells in the scheitel region on the apical pole. We have determined that Si-Vegf2 is a mesenchyme-expressed factor but its developmental function is unknown. Copyright © 2013 Elsevier B.V. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Status and applications of echinoid (phylum echinodermata) toxicity test methods

    Energy Technology Data Exchange (ETDEWEB)

    Bay, S.; Burgess, R.; Nacci, D.

    1993-01-01

    The use of echinoderms for toxicity testing has focused primarily on sea urchins and sand dollars (Strongylocentrotus purpuratus, Arbacia punctulata, Lytechinus pictus, and Dendraster excentricus, for example). The status and relative sensitivity of various test methods are described. The most frequently used test methods consist of short-term exposures of sea urchin sperm or embryos; these tests can be easily conducted at all times of the year by using species with complementary spawning cycles or laboratory conditioned populations of a single species. Data from reference toxicant and effluent toxicity tests are summarized. Information on the precision and sensitivity of echinoid test methods are limited and preclude rigorous comparisons with other test methods. The available data indicate that the sensitivity and precision of these methods are comparable to short-term chronic methods for other marine invertebrates and fish. Recent application of the sperm test in toxicity identification evaluations (TIEs) and studies of effluent toxicity decay and sediment toxicity illustrate the versatility of this rapid (10 to 60 min exposure) test method. Embryo tests typically use a 48 to 96 h exposure period and measure the occurrence of embryo malformations. Most recent applications of the embryo test have been for the assessment of sediment elutriate toxicity. Adult echinoderms are not frequently used to assess effluent or receiving water toxicity. Recent studies have had success in using the adult life stage of urchins and sand dollars to assess the effects of contaminated sediment on growth, behavior, and bioaccumulation.

  7. Phylogenomic resolution of the hemichordate and echinoderm clade.

    Science.gov (United States)

    Cannon, Johanna T; Kocot, Kevin M; Waits, Damien S; Weese, David A; Swalla, Billie J; Santos, Scott R; Halanych, Kenneth M

    2014-12-01

    Ambulacraria, comprising Hemichordata and Echinodermata, is closely related to Chordata, making it integral to understanding chordate origins and polarizing chordate molecular and morphological characters. Unfortunately, relationships within Hemichordata and Echinodermata have remained unresolved, compromising our ability to extrapolate findings from the most closely related molecular and developmental models outside of Chordata (e.g., the acorn worms Saccoglossus kowalevskii and Ptychodera flava and the sea urchin Strongylocentrotus purpuratus). To resolve long-standing phylogenetic issues within Ambulacraria, we sequenced transcriptomes for 14 hemichordates as well as 8 echinoderms and complemented these with existing data for a total of 33 ambulacrarian operational taxonomic units (OTUs). Examination of leaf stability values revealed rhabdopleurid pterobranchs and the enteropneust Stereobalanus canadensis were unstable in placement; therefore, analyses were also run without these taxa. Analyses of 185 genes resulted in reciprocal monophyly of Enteropneusta and Pterobranchia, placed the deep-sea family Torquaratoridae within Ptychoderidae, and confirmed the position of ophiuroid brittle stars as sister to asteroid sea stars (the Asterozoa hypothesis). These results are consistent with earlier perspectives concerning plesiomorphies of Ambulacraria, including pharyngeal gill slits, a single axocoel, and paired hydrocoels and somatocoels. The resolved ambulacrarian phylogeny will help clarify the early evolution of chordate characteristics and has implications for our understanding of major fossil groups, including graptolites and somasteroideans. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. ATP-binding cassette (ABC) transporter expression and localization in sea urchin development.

    Science.gov (United States)

    Shipp, Lauren E; Hamdoun, Amro

    2012-06-01

    ATP-binding cassette (ABC) transporters are membrane proteins that regulate intracellular concentrations of myriad compounds and ions. There are >100 ABC transporter predictions in the Strongylocentrotus purpuratus genome, including 40 annotated ABCB, ABCC, and ABCG "multidrug efflux" transporters. Despite the importance of multidrug transporters for protection and signaling, their expression patterns have not been characterized in deuterostome embryos. Sea urchin embryos expressed 20 ABCB, ABCC, and ABCG transporter genes in the first 58 hr of development, from unfertilized egg to early prism. We quantified transcripts of ABCB1a, ABCB4a, ABCC1, ABCC5a, ABCC9a, and ABCG2b, and found that ABCB1a mRNA was 10-100 times more abundant than other transporter mRNAs. In situ hybridization showed ABCB1a was expressed ubiquitously in embryos, while ABCC5a was restricted to secondary mesenchyme cells and their precursors. Fluorescent protein fusions showed localization of ABCB1a on apical cell surfaces, and ABCC5a on basolateral surfaces. Embryos use many ABC transporters with predicted functions in cell signaling, lysosomal and mitochondrial homeostasis, potassium channel regulation, pigmentation, and xenobiotic efflux. Detailed characterization of ABCB1a and ABCC5a revealed that they have different temporal and spatial gene expression profiles and protein localization patterns that correlate to their predicted functions in protection and development, respectively. Copyright © 2012 Wiley Periodicals, Inc.

  9. Transformation and Crystallization Energetics of Synthetic and Biogenic Amorphous Calcium Carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Radha, A. V. [Peter A. Rock Thermochemistry Lab. and Nanomaterials in the Environment, Agriculture, and Technology Organized Research Unit (NEAT ORU), Univ. of California, Davis, CA (United States); Forbes, Tori Z. [Peter A. Rock Thermochemistry Lab. and Nanomaterials in the Environment, Agriculture, and Technology Organized Research Unit (NEAT ORU), Univ. of California, Davis, CA (United States); Killian, Christopher E. [Univ. of Wisconsin, Madison, WI (United States); Gilbert, P.U.P.A [Univ. of Wisconsin, Madison, WI (United States); Navrotsky, Alexandra [Peter A. Rock Thermochemistry Lab. and Nanomaterials in the Environment, Agriculture, and Technology Organized Research Unit (NEAT ORU), Univ. of California, Davis, CA (United States)

    2010-01-01

    Amorphous calcium carbonate (ACC) is a metastable phase often observed during low temperature inorganic synthesis and biomineralization. ACC transforms with aging or heating into a less hydrated form, and with time crystallizes to calcite or aragonite. The energetics of transformation and crystallization of synthetic and biogenic (extracted from California purple sea urchin larval spicules, Strongylocentrotus purpuratus) ACC were studied using isothermal acid solution calorimetry and differential scanning calorimetry. Transformation and crystallization of ACC can follow an energetically downhill sequence: more metastable hydrated ACC → less metastable hydrated ACC→anhydrous ACC ~ biogenic anhydrous ACC→vaterite → aragonite → calcite. In a given reaction sequence, not all these phases need to occur. The transformations involve a series of ordering, dehydration, and crystallization processes, each lowering the enthalpy (and free energy) of the system, with crystallization of the dehydrated amorphous material lowering the enthalpy the most. ACC is much more metastable with respect to calcite than the crystalline polymorphs vaterite or aragonite. The anhydrous ACC is less metastable than the hydrated, implying that the structural reorganization during dehydration is exothermic and irreversible. Dehydrated synthetic and anhydrous biogenic ACC are similar in enthalpy. The transformation sequence observed in biomineralization could be mainly energetically driven; the first phase deposited is hydrated ACC, which then converts to anhydrous ACC, and finally crystallizes to calcite. The initial formation of ACC may be a first step in the precipitation of calcite under a wide variety of conditions, including geological CO₂ sequestration.

  10. Extraordinary Diversity of Immune Response Proteins among Sea Urchins: Nickel-Isolated Sp185/333 Proteins Show Broad Variations in Size and Charge

    Science.gov (United States)

    Sherman, Lauren S.; Schrankel, Catherine S.; Brown, Kristy J.; Smith, L. Courtney

    2015-01-01

    Effective protection against pathogens requires the host to produce a wide range of immune effector proteins. The Sp185/333 gene family, which is expressed by the California purple sea urchin Strongylocentrotus purpuratus in response to bacterial infection, encodes a highly diverse repertoire of anti-pathogen proteins. A subset of these proteins can be isolated by affinity to metal ions based on multiple histidines, resulting in one to four bands of unique molecular weight on standard Western blots, which vary depending on the individual sea urchin. Two dimensional gel electrophoresis (2DE) of nickel-isolated protein samples followed by Western blot was employed to detect nickel-isolated Sp185/333 (Ni-Sp185/333) proteins and to evaluate protein diversity in animals before and after immune challenge with marine bacteria. Ni-Sp185/333 proteins of the same molecular weight on standard Western blots appear as a broad complex of variants that differ in pI on 2DE Western blots. The Ni-Sp185/333 protein repertoire is variable among animals, and shows a variety of changes among individual sea urchins in response to immune challenges with both the same and different species of bacteria. The extraordinary diversity of the Ni-Sp185/333 proteins may provide significant anti-pathogen capabilities for sea urchins that survive solely on innate immunity. PMID:26406912

  11. Marine Bacteria with antimicrobials capacity isolated from cultures of bivalve mollusks

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    Fabiola Pellon

    2014-06-01

    Full Text Available Microorganisms have commonly been studied as producers of antibacterial substances; yet they are also considered producers of antifungic, antiviral, antiparasitic, citotoxics and inhibitory of other forms of cellular growth substances. This paper describes the isolation, inhibitory potential and phenotipic characterization of native bacterial strains associated to bivalve mollusks such as Argopecten purpuratus “concha de abanico” and Crassostrea gigas “ostra” in cultivation systems. From 345 marine strains collected, 20 strains were recovered that had the ability of inhibiting a wide spectrum of fish, mollusks and shellfish pathogenic bacteria; being the most sensitive pathogens Aeromonas sobria P-281, Aeromonas hydrophila ATCC 7966, Vibrio vulnificus ATCC 27562 and Vibrio parahaemolyticus ATCC 17803. The phenotipic characterization of this strains with inhibitory capacity allowed the identification of the following genera: Vibrio (40%, Aeromonas (15%, Flavobacterium (10%, Pseudomonas (5%, Moraxella (5%, Flexibacter (5%. A 20% could not be identified. The results suggest that the isolated bacteria could be used as probiotics agents for the biological control of pathogens from marine organisms of interest in mariculture.

  12. Diversidad y abundancia de moluscos en las praderas de Thalassia testudinum de la Bahía de Mochima, Parque Nacional Mochima, Venezuela

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    Antulio Prieto

    2003-06-01

    Full Text Available Se estudio la diversidad y abundancia de la comunidad béntica malacológica asociada a Thalassia testudinum en cuatro localidades de la Bahía de Mochima, Estado Sucre, Venezuela. Las muestras fueron recolectadas mensualmente en cada localidad sobre transeptos perpendiculares a diferentes profundidades (0-4m desde enero 1991 hasta diciembre 1991, utilizando una cuadrata de 0.25 m² para recolectar los organismos con el sedimento. Un total de 2 988 organismos de la infauna y epifauna, pertenecientes a las clases Gastrópoda (40 y Bivalvia (41 fueron identificados. Las especies más abundantes y en consecuencia mejor adaptadas a los habitats suministrados por la T. testudinum en la Bahía de Mochima fueron Anadara notabilis, Codakia orbicularis, Cerithium litteratum, Cerithium eburneum, Batillaria minima, Modiolus squamosus, Modulus modulus, Chione cancellata, Turritella variegata, Arca zebra, y Laevicardium laevigatum. Se determinaron diferencias significativas en el número de organismos en relación a la profundidad y el tiempo en la localidad de la Gabarra, la cual presentó los valores mas altos de diversidad total (4.51 bits/ind y mensual (2.75-3.90 bits/ind. La biomasa y la abundancia de moluscos fueron bajas y la estación mas interna (Varadero presentó los valores mas elevados. El bivalvo A. notabilis y el gastropodo Modulus modulus fueron las especies constantes en las cuatro estaciones.The diversity and abundance of benthic malacological communities associated to Thalassia testudinum beds was studied at four localities of Mochima Bay, Sucre state, Venezuela. At each locality, samples were taken monthly on perpendicular transect at different depths (0-4 m, from January 1991 to December 1991, using a quadrate (0.25 m 2 for collecting mollusks and sediments. A total of 2 988 organisms of infauna and epifauna belonging to 81 species of the classes Gastropoda (41 and Bivalvia (40 were collected. More abundant species were Anadara notabilis

  13. Ecología trófica de una especie endémica de Patagonia Sur: el Ostrero Austral (Haematopus Leucopodus en el estuario del Río Gallegos (Santa Cruz

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    Emiliano Juan Pablo Leiva

    2014-06-01

    Full Text Available Ecología trófica de una especie endémica de Patagonia sur: el Ostrero Austral (Haematopus leucopodus en el estuario del río Gallegos (Santa Cruz. Este estudio contribuye con información sobre la variación poblacional del Ostrero Austral, el comportamiento alimentario y su dieta en un sector del estuario del río Gallegos, durante el año 2010. Asimismo, se presentan las variaciones temporales en la densidad, biomasa y longitud máxima de valvas de la población de alme-jas (Darina solenoides disponibles, en la zona llamada Orenaike. La abundancia máxima de ostreros fue de 650 en el mes de marzo y el mínimo de 15 individuos en octubre. La tasa media de alimenta-ción fue de 0,67 presas/min. Los ostreros dedicaron 93,20% del tiempo a la búsqueda de alimento; mientras que el resto se distribuyó entre manipulación e ingesta de la presa, y una pequeña proporción (0,56% al acicalamiento o descanso. Las principales presas fueron los moluscos bivalvos Darina solenoides y Mytilus edulis platensis las cuales aportaron en conjunto casi el 60% de la dieta. Los poliquetos también resultaron importantes, contribuyendo con más del 40% a la alimentación. La densidad media de almejas disponibles en el sustrato fue de 56,08 ind/m2, la biomasa media de 0,189 g/ind y el largo de valva promedio de 24,89 mm. Las dimensiones medias de las presas seleccionadas por el ostrero fueron 28,25 mm de largo máximo y 12,98 mm de alto para Darina solenoides y 26,43 mm de largo máximo y 13,55 mm de alto para Mytilus edulis platensis, lo que estaría indicando que es una especie altamente selectiva en relación a las dimensiones de sus presas. La biomasa media de las presas consumidas fue de 0,194 g de peso seco/almeja.

  14. Paleoambientes lacustres en la sección inferior de la Formación Río Negro, (Mioceno - Plioceno, Río Negro, Argentina

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    Roberto Schillizzi

    2008-12-01

    Full Text Available Se estudian paleoambientes lacustres aflorantes en un sector de la plataforma marina ubicadas en la localidad de La Lobería, Provincia de Río Negro. Los medios lagunares son buenos indicadores de las modificaciones climáticas soportadas por el ambiente. La metodología aplicada para la investigación consistió en tamizados por vía seca de las psamítas, análisis con difractometría de rayos "X" de las arcillas y observaciones paleontológicas. En la plataforma intermareal se determino la presencia de tres secciones que componen el miembro inferior de la Formación Río Negro. La sección basal esta formada por areniscas finas, gris verdoso, de origen eólico y depositadas en un medio de dunas con influencia ácuea. La sección media esta constituida por limolitas arcillosas a arenosas finas, color pardo rosado, con estratificación, moldes de bivalvos dulceacuícolas e icnitas de vertebrados. Esta sección se asocia a lagunas someras y restringidas, ambiente que se habría extendido en dirección NE. Este nivel esta cubierto por la sección superior formada por areniscas gris azuladas claras, con estratificación cruzada a horizontal, depositadas en un medio eólico. En la actualidad los ambientes lagunares descriptos soportan una fuerte erosión marina.This paper describes pond paleoenvironments from a marine platform sited in La Lobería, Río Negro Province, Argentina. Ponds are good indicators of paleoenvironmental evolution because they are very sensitive to changes in climatic conditions. The methodology used for this research consisted in dry sieving, X-ray diffractometry analysis and paleontological observations. Three sections belonging to the lower section of the Río Negro formation were determined in the intertidal platform. The lower section is composed of fine-grained greenish gray sandstones deposited in an aeolian dune environment with acueos influence. The middle section consists of stratifield pinkish brown clayey to

  15. Efecto de bacterias probióticas en el cultivo larvario del ostión de placer Crassostrea corteziensis (Bivalvia: Ostreidae

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    Angel Isidro Campa-Córdova

    2011-03-01

    Full Text Available El ostión de placer u ostra del Cortés (Crassostrea corteziensis se considera como una especie con potencial para ser cultivada en gran escala. Sin embargo, al igual que en otros bivalvos, la alta mortalidad que se presenta durante la etapa larvaria y juvenil, es el principal problema que limita el desarrollo del cultivo en el laboratorio. Un método que está ganando aceptación en la acuicultura es el uso de bacterias probióticas para controlar patógenos microbianos. Este estudio analiza el efecto de estas bacterias en la supervivencia y talla final de larvas de ostión de placer Crassostrea corteziensis. Se utilizó una cepa de bacterias ácido lácticas (cepa NS61 aisladas N. subnodosus, así como de bacilos aislados de L. vannamei (Pseudomonas aeruginosa, cepa YC58 y de C. corteziensis (Burkholderia cepacia, cepa Y021. Las cepas se evaluaron por inmersión en cultivos larvarios de C. corteziensis a dos concentraciones diferentes, hasta completar el estadio pediveliger. Los organismos se trataron con bacterias ácido lácticas (Lb, una mezcla de bacilos (Lb en proporción 1:1 y un grupo control. La concentración de 1x10(4UFC/ml registró una mayor supervivencia con Lb y Mb respecto al grupo control. La supervivencia con Mb a una concentración de 1x10(5UFC/ml fue mayor que la del grupo control y del grupo tratado con Lb. Los resultados mostraron que las larvas de C. corteziensis tratadas con probióticos no incrementaron significativamente su talla respecto a las larvas del grupo control. Mientras que las tratadas con Lb a la concentración mayor, 1x10(5UFC/ml, mostraron una disminución de la supervivencia respecto a las tratadas con 1x10(4UFC/ml. Este estudio demostró el efecto benéfico de cepas probióticas utilizadas individualmente o en mezcla en el cultivo larvario de C. corteziensis.

  16. Producción secundaria e índice de condición en Arca zebra (Mollusca: Bivalvia del Golfo de Cariaco, Venezuela

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    Antulio Prieto Arcas

    2001-06-01

    Full Text Available Se estudió la biomasa, producción secundaria e índice de condición del bivalvo Arca zebra, desde agosto, 1984 hasta agosto, 1985 en Pariche, localidad situada en la costa norte del Golfo de Cariaco, Venezuela. La densidad promedio fue de 37 ind.m-2, con una mayor abundancia a 3 m de profundidad (49.75 ind.m-2. La estructura poblacional es estable con reclutamientos en octubre, diciembre 1984 y junio 19885. Los valores bimensuales de biomasa oscilaron entre 189.86 g Ps m-2 (agosto-84 y 28.51 g Ps m-2 (octubre-84, con un promedio de 93.69 g Ps m-2, y no presentaron diferencias significativas (Fs, P 0.05. Utilizando un método para poblaciones con reproducción contínua y edades no separables, se obtuvo una producción secundaria de 131.61 g Ps. m-2.año-1, y la relación P/B de1.41 año-1. La mayor producción secundaria ocurrió entre febrero 1985 y agosto 1985 (65%, con el mayor aporte por el intervalo 60.00-79.95 mm (45.73%. Se observaron cambios significativos en la variación mensual del índice de condición (IC= (Ps/ Ph x100 en dos clases de tallas analizadas, presentando los valores más altos en julio de 1985 (26.84% y el mínimo en enero de 1985 (16.31%.Production and condition index of a turkeywing (Arca zebra population were studied from August 1984 to August 1985 in Pariche, Cariaco Gulf, Venezuela. Production was studied through bimonthly collections using a method designed for populations with continuous reproduction and indistinguishable age classes. The population distribution was stable with a mean density of 37 ind.m-2. A production of 131.61 g dry weight m-2.year-1 was calcuclated from data on density, biomass and weight increase along the year. Highest production was between February 1985 and August 1985 (65% and concentrated in individuals 60.00-79.95 mm long (45.73%. There was large seasonal variation in the mean monthly condition index (IC= (Ps/Ph x100 in the two size classes examined: it reached a maximum in July 1985

  17. Triásico medio de Bugarra (Valencia. España

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    Márquez-Aliaga, A.

    1984-12-01

    ón, polígonos de expansión, impresiones de gotas de lluvia y pseudomorfos de cristales de evaporitas. En el límite entre ambos subtramos se ha hallado una abundante fauna de bivalvos: Neoschizodus laevigatus (GOLD., Plocunopsis teruelensis WURM, Bakevellia costata (SCHLOTH., Pseudocorbula gregaria (MUNST.. La presencia de D.lommeli permite datar la parte inferior como del Ladiniense superior.

  18. Moluscos asociados a las raíces sumergidas del mangle rojo Rhizophora mangle, en el Golfo de Santa Fe, Estado Sucre, Venezuela

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    B. Márquez

    2002-12-01

    Full Text Available Se realizó un estudio mensual cualitativo y cuantitativo de la comunidad de moluscos asociados a las raíces sumergidas del mangle rojo, Rhizophora mangle, entre octubre de 1998 y septiembre de 1999, en seis estaciones del Golfo de Santa Fe (Estado Sucre, Venezuela. Se colectaron e identificaron un total de 4 704 individuos pertenecientes a 45 especies de moluscos (22 gasterópodos, 15 bivalvos y 8 polyplacóforos. Las especies más abundantes fueron: Crassostrea rhizophorae, Isognomon bicolor L alatus y Brachidontes exustus. Los valores más altos de diversidad y equitabilidad, y los menores valores de dominancia, se encontraron en las estaciones tres y cuatro, mientras que lo opuesto ocurrió en las estaciones uno y dos. El análisis de afinidad mostró que en las cinco primeras estaciones las variaciones espaciales en la composición de la comunidad son mayores que las variaciones temporales, mientras que en la estación seis priman las diferencias temporales. Se encontraron factores que podrían ser importantes para determinar la estructura de la comunidad, como vecindad a otros ecosistemas y/6 aspectos biológicos específicos de las especies como adaptaciones a condiciones fluctuantes, hábitos alimenticios y migración en busca de ambientes sombreados y protegidos.A qualitative and quantitative monthly study of the mollusks community associated to the submered roots of the red mangrove, Rhizophora mangle (L., between October of 1998 and September of 1999, in six stations of the Gulf of Santa Fe. (Suere State, Venezuela. Were collected 4 704 specimens, 45 species of mollusks were identified (22 gastropods, 15 bivalves and 8 chitons. The most abundant species were: Crassostrea rhizophorae, Isognomon bicolor, L alatus and Brachidontes exustus. The highest values in diversity and evenness, and the smallest dominant values, were in the stations three and four, while the opposed happened in the stations one and two. The analysis of likeness

  19. Molluscs from the fossil site of "Lo Hueco" (Upper Cretaceous, Cuenca, Spain: Palaeoenvironmental and sequential implications

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    Callapez, P. M.

    2013-12-01

    conchas bien preservadas ha obligado a la utilización de nomenclatura abierta. Los bivalvos identificados se encuentran representados por moldes margosos desarticulados de Margaritifera sp., Anodonta sp., ?Corbicula sp. y Pisidium sp., y la mayoría de los gasterópodos por moldes de yeso de Faunus sp. Esta asociación corresponde a una típica paleofauna de agua dulce, en la que la presencia de gasterópodos melanópsidos parece sugerir la influencia esporádica de episodios de agua salobre. Estos datos confirman las interpretaciones paleoambientales previas propuestas para el yacimiento. Adicionalmente, la presencia del gasterópodo terrestre Palaeocyclophorus sp. en niveles infrayacentes con una elevada proporción de materia orgánica vegetal, situados sobre una importante discordancia erosiva, ha permitido localizar el inicio de la secuencia deposicional correspondiente a "Lo Hueco".

  20. La contaminación por metales pesados en la Ciénaga Grande de Santa Marta, Caribe colombiano La contaminación por metales pesados en la Ciénaga Grande de Santa Marta, Caribe colombiano

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    Campos C. Néstor Hernando

    1990-09-01

    Full Text Available Se dan los resultados de los estudios sobre la contaminación por metales pesados en la Ciénaga Grande de Santa Marta. Las determinaciones se realizaron en el material en suspensión, en los bivalvos Crassostrea rhizophorae e Isognomon alatus y en los peces Gathorops spixii y Ariopsis bonillai. Los análisis de los metales Cd, Zn y Cu en el material en suspensión permitieron determinar que las mayores descargas de estos metales se suceden principalmente desde el Río Magdalena a través del Canal del Clarín y de los ríos que fluyen del piedemonte de la Sierra Nevada de Santa Marta. La comparación de los contenidos en bivalvas permiten determinar la importancia de estos organismos como bioindicadores. Los análisis en las dos especies de peces mostraron una diferenciación en la capacidad de acumulación entre una y otra.  Al comparar los contenidos de metales entre los diferentes tipos de muestras con los cambios en los contenidos en el material en suspensión y la salinidad, se observó que estos dos parámetros son principalmente los que controlan la biodisponibilidad de los metales y además afectan los procesos fisiológicos de los organismos, aumentando o disminuyendo la capacidad de bioacumulación. Results of the studies of heavy metals pollution in the Ciénaga Grande de Santa Marta are provided. The determinations have been done on the suspended matter, on the bivalves Crassostrea rhizophorae and Isognomon alatus, and in the fishes Gathorops spixii and Ariopsis bonillai. The analysis of Cd, Zn and Cu in the suspended matter led to determine that the discharges come principally from the Río Magdalena through the Canal del Clarín and the rivers coming from the Sierra Nevada de Santa Marta. Comparisons of the concentration in bivalves show the importance of this organisms as bioindicators. The analysis in both fish species show a difference in their capacity of accumulation. Comparison of the metals contents between different types

  1. Cambios alimenticios en tres especies de Sphoeroides (Tetraodontiformes: Tetraodontidae posterior al huracán Isidoro en Bocana de la Carbonera, Sureste del Golfo de México

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    Sonia Eugenia Palacios-Sánchez

    2010-12-01

    Full Text Available Se analizan los cambios producidos por el huracán Isidoro en la repartición de los recursos alimenticios de tres especies de peces de la familia Tetraodontidae (Sphoeroides nephelus, S. spengleri y S testudineus que cohabitan en la Bocana de la Carbonera (sureste del Golfo de México. Los Sphoeroides spp. basaron su alimentación en los organismos bentónicos, sobresaliendo por su consumo el mejillón (Brachidontes sp., la lapa (Balanus sp. y gasterópodos (Crepidula sp.. Previo al impacto del huracán, las tres especies utilizaron de forma diferencial los recursos alimenticios disponibles (bivalvos, gasterópodos, cirrípedos y decápodos recurriendo a diferentes estrategias que les permitieron minimizar la competencia interespecífica y coexistir. Posterior al impacto, la disponibilidad de las presas disminuyó y la competencia interespecífica por el alimento se incrementó provocando que S. testudineus y S. nephelus cambiaran su espectro trófico (xiphosuros, anfípodos, isópodos y detritus desplazando a S. spengleri de la bocana. La repartición de los recursos alimenticios estuvo condicionada por la abundancia y diversidad de las presas así como la respuesta adaptativa de cada especie.Feeding changes for three Sphoeroides species (Tetraodontiformes: Tetraodontidae after Isidore hurricane impact in Carbonera Inlet, Southeastern Gulf of Mexico. The coexistence of ecologically similar species may occur because of resources distribution, such as prey and habitat type and segregation time, that minimizes the interspecific competition. The changes brought about by Hurricane Isidore in the distribution of food resources by three coexisting fish species of the family Tetraodontidae (Sphoeroides nephelus, S. spengleri and S testudineus, were analyzed at the Carbonera Inlet. Sphoeroides spp. based their food on benthic organisms; principally, they consume mussels (Brachidontes sp., barnacles (Balanus sp. and gastropods (Crepidula sp. Before

  2. First report of diarrheic shellfish toxins in mollusks from Buenos Aires province (Argentina associated with dinophysis spp.: evidence of okadaic acid, dinophysistoxin-1 and their acylderivatives

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    Eugenia A Sar

    2012-06-01

    Full Text Available In January 2010, the toxin-producing dinoflagellates Dinophysis acuminata and D. caudata (10³ cells·l-1 were detected in Mar Azul during routine plankton monitoring in Buenos Aires Province coastal waters, Argentina. Wild clams Mesodesma mactroides and Donax hanleyanus from Mar Azul intertidal beach, which are part of the diet for local inhabitants and tourists, tested positive with the offcial lipophilic mouse bioassay. This paper focuses on the detection of Diarrhetic Shellfsh Poison (DSP toxins in these samples using a HPLC-FLD pre column derivatization procedure. The data showed that shellfish were contaminated with complex DSP toxin profiles composed of Okadaic Acid (OA, Dinophysistoxin-1 (DTX-1, Acyl-Dinophysistoxin-1 (Acyl-DTX-1 and Acyl-Okadaic Acid (Acyl-OA. The DSP toxins found in this study produce diarrhea symptoms consistent with those experienced by patients who had ingested cooked shellfish in January. This is the first report of Acyl-derivatives in South American Atlantic shellfish samples and of OA in Argentinean shellfish samples.Primer reporte de toxinas diarreicas de moluscos en bivalvos de la Provincia de Buenos Aires (Argentina asociado con Dinophysis spp.: evidencia de Ácido Okadaico, Dinophysistoxina-1 y sus acyl-derivados. En enero de 2010, los dinoflagelados productores de toxinas Dinophysis acuminata y D. caudata (10³ cells·l-1 fueron detectados en Mar Azul durante un monitoreo rutinario de fitoplancton realizado en aguas costeras de la Provincia de Buenos Aires, Argentina. Mesodesma mactroides (almeja amarilla y Donax hanleyanus (berberecho del intermareal de Mar Azul, que son parte de la dieta de los habitantes del lugar y de turistas, dieron resultado positivo para toxinas lipofílicas mediante bioensayo ratón. Este trabajo está focalizado en la detección de Toxinas Diarreicas de Moluscos (DSP en muestras colectadas durante el evento de toxicidad usando un HPLC-FLD con procedimiento de derivatizaci

  3. Comunidad de moluscos asociados al mejillón verde Perna viridis (Mollusca: Bivalvia y sus relaciones tróficas en la costa norte de la Península de Araya, Estado Sucre, Venezuela

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    Sioliz Villafranca

    2006-12-01

    Full Text Available Perna viridis es un bivalvo procedente del Indo-Pacífico que habita en la zona intermareal y ha invadido varios ecosistemas de la costa norte del estado Sucre, Venezuela. Con la finalidad de realizar un estudio sobre las comunidades de moluscos asociadas a esta especie y sus relaciones tróficas, se llevaron a cabo muestreos bimensuales entre octubre/97 y agosto/98, en un banco natural de mejillones a dos metros de profundidad en la costa norte de la península de Araya (10°40’N -48°63’W. Los organismos fueron recolectados delimitando el área con una cuadrícula de 0.25 m². Se identificaron los organismos hasta la categoría de especies utilizando claves específicas para moluscos y bibliográficamente se les determinó categoría trófica.Se capturó un total de 1 235 individuos de P. viridis y asociados a la especie 3 163 especímenes pertenecientes al phylum Mollusca, contenidos en tres clases: Bivalvia,Gastropoda y Polyplacophora. Éstas estuvieron representadas por 50 especies correspondientes a 10 órdenes, 24 familias; para los gasterópodos se contabilizaron 25 especies, para los bivalvos 22 y tres para los poliplacóforos. Del total de las especies, 40% fueron filtradoras, 26% carnívoras, 24% herbívoras y el 10% restante presentó dos categorías.De las filtradoras las más representativas fueron: Perna perna, Musculus lateralis, Crassostrea rhizophorae y Ostrea equestris; en el grupo de los carnívoros dominaron tres especies de la familia Columbellidae:Mitrella lunata, Anachis obesa y Nitidella ocellata y para el grupo de los herbívoros destacaron dos especies de la familia Fisurellidae: Diodora cayenensis y D. minuta. Se registraron dos especies filtradoras-detritívoras, y tres especies herbívoras-filtradoras representantes del género C repidula. El alto porcentaje de filtradores sería un indicativo de que dentro de este sistema probablemente hay una mayor disponibilidad de fracciones alimenticias para este grupo

  4. MicroRNAs support the monophyly of enteropneust hemichordates.

    Science.gov (United States)

    Peterson, Kevin J; Su, Yi-Hsien; Arnone, Maria Ina; Swalla, Billie; King, Benjamin L

    2013-09-01

    Understanding the evolutionary history of deuterostomes requires elucidating the phylogenetic interrelationships amongst the constituent taxa. Although the monophyly and interrelationships among the three principal groups-the chordates, the echinoderms, and the hemichordates-are well established, as are the internal relationships among the echinoderm and chordate taxa, the interrelationships among the principal groups of hemichordates-the harrimaniid enteropneusts, the ptychoderid enteropneusts, and the pterobranchs-remain unresolved. Depending on the study some find enteropneusts paraphyletic with pterobranchs (e.g., Cephalodiscus) more closely related to the harrimaniid enteropneusts (e.g., Saccoglossus) than either are to the ptychoderid enteropneusts (e.g., Ptychodera), whereas other studies support a monophyletic Enteropneusta. To try and resolve between these two competing hypotheses, we turned to microRNAs, small ∼22 nt non-coding RNA genes that have been shown to shed insight into particularly difficult phylogenetic questions. Using deep sequencing we characterized the small RNA repertoires of two hemichordate species, Cephalodiscus hodgsoni and Ptychodera flava, and the crinoid echinoderm Antedon mediterranea, and combined our results with the described complements of the hemichordate Saccoglossus kowalevskii, the sea urchin Strongylocentrotus purpuratus, and the starfish Patiria miniata. Our data unambiguously support the monophyly of Enteropneusts as S. kowalevskii shares 12 miRNA sequences with P. flava that are not present in the C. hodgsoni or A. mediterranea libraries, and have never been reported from another metazoan taxon. Thus, these data resolve the phylogenetic position of pterobranchs, ultimately allowing for a better understanding of body plan evolution throughout the deuterostomes. Copyright © 2013 Wiley Periodicals, Inc.

  5. Comparative genomics of neuroglobin reveals its early origins.

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    Jasmin Dröge

    Full Text Available Neuroglobin (Ngb is a hexacoordinated globin expressed mainly in the central and peripheral nervous system of vertebrates. Although several hypotheses have been put forward regarding the role of neuroglobin, its definite function remains uncertain. Ngb appears to have a neuro-protective role enhancing cell viability under hypoxia and other types of oxidative stress. Ngb is phylogenetically ancient and has a substitution rate nearly four times lower than that of other vertebrate globins, e.g. hemoglobin. Despite its high sequence conservation among vertebrates Ngb seems to be elusive in invertebrates.We determined candidate orthologs in invertebrates and identified a globin of the placozoan Trichoplax adhaerens that is most likely orthologous to vertebrate Ngb and confirmed the orthologous relationship of the polymeric globin of the sea urchin Strongylocentrotus purpuratus to Ngb. The putative orthologous globin genes are located next to genes orthologous to vertebrate POMT2 similarly to localization of vertebrate Ngb. The shared syntenic position of the globins from Trichoplax, the sea urchin and of vertebrate Ngb strongly suggests that they are orthologous. A search for conserved transcription factor binding sites (TFBSs in the promoter regions of the Ngb genes of different vertebrates via phylogenetic footprinting revealed several TFBSs, which may contribute to the specific expression of Ngb, whereas a comparative analysis with myoglobin revealed several common TFBSs, suggestive of regulatory mechanisms common to globin genes.Identification of the placozoan and echinoderm genes orthologous to vertebrate neuroglobin strongly supports the hypothesis of the early evolutionary origin of this globin, as it shows that neuroglobin was already present in the placozoan-bilaterian last common ancestor. Computational determination of the transcription factor binding sites repertoire provides on the one hand a set of transcriptional factors that are

  6. Phylogeny of Echinoderm Hemoglobins.

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    Ana B Christensen

    Full Text Available Recent genomic information has revealed that neuroglobin and cytoglobin are the two principal lineages of vertebrate hemoglobins, with the latter encompassing the familiar myoglobin and α-globin/β-globin tetramer hemoglobin, and several minor groups. In contrast, very little is known about hemoglobins in echinoderms, a phylum of exclusively marine organisms closely related to vertebrates, beyond the presence of coelomic hemoglobins in sea cucumbers and brittle stars. We identified about 50 hemoglobins in sea urchin, starfish and sea cucumber genomes and transcriptomes, and used Bayesian inference to carry out a molecular phylogenetic analysis of their relationship to vertebrate sequences, specifically, to assess the hypothesis that the neuroglobin and cytoglobin lineages are also present in echinoderms.The genome of the sea urchin Strongylocentrotus purpuratus encodes several hemoglobins, including a unique chimeric 14-domain globin, 2 androglobin isoforms and a unique single androglobin domain protein. Other strongylocentrotid genomes appear to have similar repertoires of globin genes. We carried out molecular phylogenetic analyses of 52 hemoglobins identified in sea urchin, brittle star and sea cucumber genomes and transcriptomes, using different multiple sequence alignment methods coupled with Bayesian and maximum likelihood approaches. The results demonstrate that there are two major globin lineages in echinoderms, which are related to the vertebrate neuroglobin and cytoglobin lineages. Furthermore, the brittle star and sea cucumber coelomic hemoglobins appear to have evolved independently from the cytoglobin lineage, similar to the evolution of erythroid oxygen binding globins in cyclostomes and vertebrates.The presence of echinoderm globins related to the vertebrate neuroglobin and cytoglobin lineages suggests that the split between neuroglobins and cytoglobins occurred in the deuterostome ancestor shared by echinoderms and vertebrates.

  7. Acute effects of non-weathered and weathered crude oil and dispersant associated with the Deepwater Horizon incident on the development of marine bivalve and echinoderm larvae.

    Science.gov (United States)

    Stefansson, Emily S; Langdon, Chris J; Pargee, Suzanne M; Blunt, Susanna M; Gage, Susan J; Stubblefield, William A

    2016-08-01

    Acute toxicity tests (48-96-h duration) were conducted with larvae of 2 echinoderm species (Strongylocentrotus purpuratus and Dendraster excentricus) and 4 bivalve mollusk species (Crassostrea virginica, Crassostrea gigas, Mytilus galloprovincialis, and Mercenaria mercenaria). Developing larvae were exposed to water-accommodated fractions (WAFs) and chemically enhanced water-accommodated fractions (CEWAFs) of fresh and weathered oils collected from the Gulf of Mexico during the Deepwater Horizon incident. The WAFs (oils alone), CEWAFs (oils plus Corexit 9500A dispersant), and WAFs of Corexit alone were prepared using low-energy mixing. The WAFs of weathered oils had no effect on survival and development of echinoderm and bivalve larvae, whereas WAFs of fresh oils showed adverse effects on larval development. Similar toxicities were observed for weathered oil CEWAFs and WAFs prepared with Corexit alone for oyster (C. gigas and C. virginica) larvae, which were the most sensitive of the tested invertebrate species to Corexit. Mean 10% effective concentration values for total polycyclic aromatic hydrocarbons and dipropylene glycol n-butyl ether (a marker for Corexit) in the present study were higher than all concentrations reported in nearshore field samples collected during and after the Deepwater Horizon incident. The results suggest that water-soluble fractions of weathered oils and Corexit dispersant associated with the Deepwater Horizon incident had limited, if any, acute impacts on nearshore larvae of eastern oysters and clams, as well as other organisms with similar sensitivities to those of test species in the present study; however, exposure to sediments and long-term effects were not evaluated. Environ Toxicol Chem 2016;35:2016-2028. © 2016 SETAC. © 2016 SETAC.

  8. An evolutionary transition of vasa regulation in echinoderms

    Science.gov (United States)

    Juliano, Celina E.; Wessel, Gary M.

    2011-01-01

    Summary Vasa, a DEAD box helicase, is a germline marker that may also function in multipotent cells. In the embryo of the sea urchin Strongylocentrotus purpuratus, Vasa protein is posttranscriptionally enriched in the small micromere lineage, which results from two asymmetric cleavage divisions early in development. The cells of this lineage are subsequently set aside during embryogenesis for use in constructing the adult rudiment. Although this mode of indirect development is prevalent among echinoderms, early asymmetric cleavage divisions are a derived feature in this phylum. The goal of this study is to explore how vasa is regulated in key members of the phylum with respect to the evolution of the micromere and small micromere lineages. We find that although striking similarities exist between the vasa mRNA expression patterns of several sea urchins and sea stars, the time frame of enriched protein expression differs significantly. These results suggest that a conserved mechanism of vasa regulation was shifted earlier in sea urchin embryogenesis with the derivation of micromeres. These data also shed light on the phenotype of a sea urchin embryo upon removal of the Vasa-positive micromeres, which appears to revert to a basal mechanism used by extant sea stars and pencil urchins to regulate Vasa protein accumulation. Furthermore, in all echinoderms tested here, Vasa protein and/or message is enriched in the larval coelomic pouches, the site of adult rudiment formation, thus suggesting a conserved role for vasa in undifferentiated multipotent cells set aside during embryogenesis for use in juvenile development. PMID:19754712

  9. Identification of sublethal toxicants in a BC coastal pulp and paper mill effluent

    Energy Technology Data Exchange (ETDEWEB)

    Eickhoff, C.V.; Pickard, J.; Kinnee, K. [BC Research Inc., Vancouver, BC (Canada); Dwernychuk, W. [Hatfield Consultants Ltd., West Vancouver, BC (Canada); Birkholz, D. [EnviroTest Lab., Edmonton, AB (Canada); Kilback, D. [Pacifica Papers, Powell River, BC (Canada)

    2001-06-01

    BC Research Inc. conducted a toxicity identification evaluation to identify the different compounds comprised in the mill Outfall number 1 effluent. The Environmental Effects Monitoring program had determined that these compounds were responsible for sublethal effects to organisms. Echinoderm species like the sand dollar, Dendraster excentricus Eshscholtz, the purple sea urchin, Stronglyocentrotus purpuratus Stimpson, and the marine algae, Champia parvula had suffered toxicity caused by the mill effluent. The last several Environmental Effects Monitoring testing periods had shown the sublethal toxicity of the Outfall number 1 effluent to echinoderms was very consistent. Based on the high cost and shipping associated with the Champia bioassays, toxicity tests conducted during the peak spawning season of the sea urchin and the non significant difference between the sensitivity of the sand dollar and the purple sea urchin, the purple sea urchin was selected to evaluate the toxicity of the manipulated samples for the tests. The tests conducted were: a baseline toxicity test performed immediately upon receipt of the effluent sample, the pH adjustment filtration test to determine if the toxic compound can be removed using filtration, the pH adjustment aeration test to determine if volatile compounds in the sample are toxic, the pH adjustment solid phase extraction test to determine the level of toxicity from organic compounds and metal chelates that can be removed by solid phase extraction. The results indicated that it seems high molecular weight molecules were responsible for the sublethal toxicity observed. Two different sources could be responsible: lignin derived macromolecules, and polymer compounds used as flocculants and sizing agents. Further testing of the pulp mill effluent to identify the source of the toxic high molecular weight compounds was recommended. 22 refs., 4 tabs., 6 figs.

  10. Phylogeny of Echinoderm Hemoglobins.

    Science.gov (United States)

    Christensen, Ana B; Herman, Joseph L; Elphick, Maurice R; Kober, Kord M; Janies, Daniel; Linchangco, Gregorio; Semmens, Dean C; Bailly, Xavier; Vinogradov, Serge N; Hoogewijs, David

    2015-01-01

    Recent genomic information has revealed that neuroglobin and cytoglobin are the two principal lineages of vertebrate hemoglobins, with the latter encompassing the familiar myoglobin and α-globin/β-globin tetramer hemoglobin, and several minor groups. In contrast, very little is known about hemoglobins in echinoderms, a phylum of exclusively marine organisms closely related to vertebrates, beyond the presence of coelomic hemoglobins in sea cucumbers and brittle stars. We identified about 50 hemoglobins in sea urchin, starfish and sea cucumber genomes and transcriptomes, and used Bayesian inference to carry out a molecular phylogenetic analysis of their relationship to vertebrate sequences, specifically, to assess the hypothesis that the neuroglobin and cytoglobin lineages are also present in echinoderms. The genome of the sea urchin Strongylocentrotus purpuratus encodes several hemoglobins, including a unique chimeric 14-domain globin, 2 androglobin isoforms and a unique single androglobin domain protein. Other strongylocentrotid genomes appear to have similar repertoires of globin genes. We carried out molecular phylogenetic analyses of 52 hemoglobins identified in sea urchin, brittle star and sea cucumber genomes and transcriptomes, using different multiple sequence alignment methods coupled with Bayesian and maximum likelihood approaches. The results demonstrate that there are two major globin lineages in echinoderms, which are related to the vertebrate neuroglobin and cytoglobin lineages. Furthermore, the brittle star and sea cucumber coelomic hemoglobins appear to have evolved independently from the cytoglobin lineage, similar to the evolution of erythroid oxygen binding globins in cyclostomes and vertebrates. The presence of echinoderm globins related to the vertebrate neuroglobin and cytoglobin lineages suggests that the split between neuroglobins and cytoglobins occurred in the deuterostome ancestor shared by echinoderms and vertebrates.

  11. Transcriptome sequencing and characterization for the sea cucumber Apostichopus japonicus (Selenka, 1867.

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    Huixia Du

    Full Text Available BACKGROUND: Sea cucumbers are a special group of marine invertebrates. They occupy a taxonomic position that is believed to be important for understanding the origin and evolution of deuterostomes. Some of them such as Apostichopus japonicus represent commercially important aquaculture species in Asian countries. Many efforts have been devoted to increasing the number of expressed sequence tags (ESTs for A. japonicus, but a comprehensive characterization of its transcriptome remains lacking. Here, we performed the large-scale transcriptome profiling and characterization by pyrosequencing diverse cDNA libraries from A. japonicus. RESULTS: In total, 1,061,078 reads were obtained by 454 sequencing of eight cDNA libraries representing different developmental stages and adult tissues in A. japonicus. These reads were assembled into 29,666 isotigs, which were further clustered into 21,071 isogroups. Nearly 40% of the isogroups showed significant matches to known proteins based on sequence similarity. Gene ontology (GO and KEGG pathway analyses recovered diverse biological functions and processes. Candidate genes that were potentially involved in aestivation were identified. Transcriptome comparison with the sea urchin Strongylocentrotus purpuratus revealed similar patterns of GO term representation. In addition, 4,882 putative orthologous genes were identified, of which 202 were not present in the non-echinoderm organisms. More than 700 simple sequence repeats (SSRs and 54,000 single nucleotide polymorphisms (SNPs were detected in the A. japonicus transcriptome. CONCLUSION: Pyrosequencing was proven to be efficient in rapidly identifying a large set of genes for the sea cucumber A. japonicus. Through the large-scale transcriptome sequencing as well as public EST data integration, we performed a comprehensive characterization of the A. japonicus transcriptome and identified candidate aestivation-related genes. A large number of potential genetic

  12. The skeletal proteome of the brittle star Ophiothrix spiculata identifies C-type lectins and other proteins conserved in echinoderm skeleton formation

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    Brian T. Livingston

    2016-07-01

    Full Text Available Determining the identity and functional role of proteins involved in biomineralization and the formation of skeletons is critical to our understanding of the process. Proteomics has allowed rapid characterization of the proteins occluded within mineralized tissue, but the large numbers of proteins detected makes it difficult to assign the relative importance of each protein. We have taken a comparative approach, examining the skeletal proteome of different species of echinoderms in order to identify the proteins that are conserved and likely to be important. Our previous study comparing the skeletal proteome of the brittle star Ophiocoma wendtii to the published proteomes of the sea urchin Strongylocentrotus purpuratus revealed some conservation of proteins, but indicated that the C-type lectin domain-containing spicule matrix proteins abundant in the sea urchin skeletal proteome were not conserved in the brittle star. Here we examine the skeletal proteome of a different species of brittle star, Ophiothrix spiculata. We have isolated the proteins from the skeleton of O. spiculata and performed LC/MS/MS to identify peptides present. Comparison to transcriptome and genome databases revealed the proteins present in the O. spiculata proteome. Despite being diverged for several million years, the two brittle stars have very similar proteins in their skeletons. Included is a fibrinogen C-like lectin and several C-type lectins proteins, which we describe in detail. The unusual number of C-type lectins found in the S. purpuatus skeleton and the repetitive regions seen in those spicule matrix proteins are not present in O. spiculata.

  13. RNA deep sequencing reveals differential microRNA expression during development of sea urchin and sea star.

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    Sabah Kadri

    Full Text Available 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 during development in these organisms, except that the genes that are involved in the miRNA biogenesis pathway are expressed during their developmental stages. In this paper, we used Illumina Genome Analyzer (Illumina, Inc. to sequence small RNA libraries in mixed stage population of embryos from one to three days after fertilization of sea urchin and sea star (total of 22,670,000 reads. Analysis of these data revealed the miRNA populations in these two species. We found that 47 and 38 known miRNAs are expressed in sea urchin and sea star, respectively, during early development (32 in common. We also found 13 potentially novel miRNAs in the sea urchin embryonic library. miRNA expression is generally conserved between the two species during development, but 7 miRNAs are highly expressed in only one species. We expect that our two datasets will be a valuable resource for everyone working in the field of developmental biology and the regulatory networks that affect it. The computational pipeline to analyze Illumina reads is available at http://www.benoslab.pitt.edu/services.html.

  14. RNA deep sequencing reveals differential microRNA expression during development of sea urchin and sea star.

    Science.gov (United States)

    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 during development in these organisms, except that the genes that are involved in the miRNA biogenesis pathway are expressed during their developmental stages. In this paper, we used Illumina Genome Analyzer (Illumina, Inc.) to sequence small RNA libraries in mixed stage population of embryos from one to three days after fertilization of sea urchin and sea star (total of 22,670,000 reads). Analysis of these data revealed the miRNA populations in these two species. We found that 47 and 38 known miRNAs are expressed in sea urchin and sea star, respectively, during early development (32 in common). We also found 13 potentially novel miRNAs in the sea urchin embryonic library. miRNA expression is generally conserved between the two species during development, but 7 miRNAs are highly expressed in only one species. We expect that our two datasets will be a valuable resource for everyone working in the field of developmental biology and the regulatory networks that affect it. The computational pipeline to analyze Illumina reads is available at http://www.benoslab.pitt.edu/services.html. © 2011 Kadri et al.

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

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    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.

  16. Trophic and environmental drivers of the Sechura Bay Ecosystem (Peru) over an ENSO cycle

    Science.gov (United States)

    Taylor, Marc H.; Wolff, Matthias; Vadas, Flora; Yamashiro, Carmen

    2008-03-01

    Interannual environmental variability in Peru is dominated by the El Niño Southern Oscillation (ENSO). The most dramatic changes are associated with the warm El Niño (EN) phase (opposite the cold La Niña phase), which disrupts the normal coastal upwelling and affects the dynamics of many coastal marine and terrestrial resources. This study presents a trophic model for Sechura Bay, located at the northern extension of the Peruvian upwelling system, where ENSO-induced environmental variability is most extreme. Using an initial steady-state model for the year 1996, we explore the dynamics of the ecosystem through the year 2003 (including the strong EN of 1997/98 and the weaker EN of 2002/03). Based on support from literature, we force biomass of several non-trophically-mediated ‘drivers’ (e.g. Scallops, Benthic detritivores, Octopus, and Littoral fish) to observe whether the fit between historical and simulated changes (by the trophic model) is improved. The results indicate that the Sechura Bay Ecosystem is a relatively inefficient system from a community energetics point of view, likely due to the periodic perturbations of ENSO. A combination of high system productivity and low trophic level target species of invertebrates (i.e. scallops) and fish (i.e. anchoveta) results in high catches and an efficient fishery. The importance of environmental drivers is suggested, given the relatively small improvements in the fit of the simulation with the addition of trophic drivers on remaining functional groups’ dynamics. An additional multivariate regression model is presented for the scallop Argopecten purpuratus, which demonstrates a significant correlation between both spawning stock size and riverine discharge-mediated mortality on catch levels. These results are discussed in the context of the appropriateness of trophodynamic modeling in relatively open systems, and how management strategies may be focused given the highly environmentally influenced marine

  17. Microplate assay for quantifying developmental morphologies: effects of exogenous hyalin on sea urchin gastrulation.

    Science.gov (United States)

    Razinia, Z; Carroll, E J; Oppenheimer, S B

    2007-05-01

    It is often difficult to determine the effects of various substances on the development of the sea urchin embryo due to the lack of appropriate quantitative microassays. Here, a microplate assay has been developed for quantitatively evaluating the effects of substances, such as hyalin, on living sea urchin embryos. Hyalin (330 kDa) is a major constituent of the sea urchin hyaline layer, an extracellular matrix that develops 20 min postinsemination. Function of the hyaline layer and its major constituent, is the adhesion of cells during morphogenesis. Using wide-mouthed pipette tips, 25 microl of 24-h Strongylocentrotus purpuratus embryos were transferred to each well of a 96-well polystyrene flat-bottom microplate yielding about 12 embryos per well. Specific concentrations of purified hyalin diluted in low calcium seawater were added to the wells containing the embryos, which were then incubated for 24 h at 15 degree C. The hyalin-treated and control samples were observed live and after fixation with 10% formaldehyde using a Zeiss Axiolab photomicroscope. The small number of embryos in each well allowed quantification of the developmental effects of the added media. Specific archenteron morphologies-attached, unattached, no invagination and exogastrula-were scored and a dose-dependent response curve was generated. Hyalin at high concentrations blocked invagination. At low concentrations, it inhibited archenteron elongation/attachment to the blastocoel roof. While many studies have implicated hyalin in a variety of interactions during morphogenesis, we are not aware of any past studies that have quantitatively examined the effects of exogenous hyalin on specific gastrulation events in whole embryos.

  18. Unique system of photoreceptors in sea urchin tube feet

    Science.gov (United States)

    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

  19. Experimental ocean acidification alters the allocation of metabolic energy.

    Science.gov (United States)

    Pan, T-C Francis; Applebaum, Scott L; Manahan, Donal T

    2015-04-14

    Energy is required to maintain physiological homeostasis in response to environmental change. Although responses to environmental stressors frequently are assumed to involve high metabolic costs, the biochemical bases of actual energy demands are rarely quantified. We studied the impact of a near-future scenario of ocean acidification [800 µatm partial pressure of CO2 (pCO2)] during the development and growth of an important model organism in developmental and environmental biology, the sea urchin Strongylocentrotus purpuratus. Size, metabolic rate, biochemical content, and gene expression were not different in larvae growing under control and seawater acidification treatments. Measurements limited to those levels of biological analysis did not reveal the biochemical mechanisms of response to ocean acidification that occurred at the cellular level. In vivo rates of protein synthesis and ion transport increased ∼50% under acidification. Importantly, the in vivo physiological increases in ion transport were not predicted from total enzyme activity or gene expression. Under acidification, the increased rates of protein synthesis and ion transport that were sustained in growing larvae collectively accounted for the majority of available ATP (84%). In contrast, embryos and prefeeding and unfed larvae in control treatments allocated on average only 40% of ATP to these same two processes. Understanding the biochemical strategies for accommodating increases in metabolic energy demand and their biological limitations can serve as a quantitative basis for assessing sublethal effects of global change. Variation in the ability to allocate ATP differentially among essential functions may be a key basis of resilience to ocean acidification and other compounding environmental stressors.

  20. An Elk transcription factor is required for Runx-dependent survival signaling in the sea urchin embryo.

    Science.gov (United States)

    Rizzo, Francesca; Coffman, James A; Arnone, Maria Ina

    2016-08-01

    Elk proteins are Ets family transcription factors that regulate cell proliferation, survival, and differentiation in response to ERK (extracellular-signal regulated kinase)-mediated phosphorylation. Here we report the embryonic expression and function of Sp-Elk, the single Elk gene of the sea urchin Strongylocentrotus purpuratus. Sp-Elk is zygotically expressed throughout the embryo beginning at late cleavage stage, with peak expression occurring at blastula stage. Morpholino antisense-mediated knockdown of Sp-Elk causes blastula-stage developmental arrest and embryo disintegration due to apoptosis, a phenotype that is rescued by wild-type Elk mRNA. Development is also rescued by Elk mRNA encoding a serine to aspartic acid substitution (S402D) that mimics ERK-mediated phosphorylation of a conserved site that enhances DNA binding, but not by Elk mRNA encoding an alanine substitution at the same site (S402A). This demonstrates both that the apoptotic phenotype of the morphants is specifically caused by Elk depletion, and that phosphorylation of serine 402 of Sp-Elk is critical for its anti-apoptotic function. Knockdown of Sp-Elk results in under-expression of several regulatory genes involved in cell fate specification, cell cycle control, and survival signaling, including the transcriptional regulator Sp-Runt-1 and its target Sp-PKC1, both of which were shown previously to be required for cell survival during embryogenesis. Both Sp-Runt-1 and Sp-PKC1 have sequences upstream of their transcription start sites that specifically bind Sp-Elk. These results indicate that Sp-Elk is the signal-dependent activator of a feed-forward gene regulatory circuit, consisting also of Sp-Runt-1 and Sp-PKC1, which actively suppresses apoptosis in the early embryo. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Perturbation of gut bacteria induces a coordinated cellular immune response in the purple sea urchin larva.

    Science.gov (United States)

    Ch Ho, Eric; Buckley, Katherine M; Schrankel, Catherine S; Schuh, Nicholas W; Hibino, Taku; Solek, Cynthia M; Bae, Koeun; Wang, Guizhi; Rast, Jonathan P

    2016-10-01

    The purple sea urchin (Strongylocentrotus purpuratus) genome sequence contains a complex repertoire of genes encoding innate immune recognition proteins and homologs of important vertebrate immune regulatory factors. To characterize how this immune system is deployed within an experimentally tractable, intact animal, we investigate the immune capability of the larval stage. Sea urchin embryos and larvae are morphologically simple and transparent, providing an organism-wide model to view immune response at cellular resolution. Here we present evidence for immune function in five mesenchymal cell types based on morphology, behavior and gene expression. Two cell types are phagocytic; the others interact at sites of microbial detection or injury. We characterize immune-associated gene markers for three cell types, including a perforin-like molecule, a scavenger receptor, a complement-like thioester-containing protein and the echinoderm-specific immune response factor 185/333. We elicit larval immune responses by (1) bacterial injection into the blastocoel and (2) seawater exposure to the marine bacterium Vibrio diazotrophicus to perturb immune state in the gut. Exposure at the epithelium induces a strong response in which pigment cells (one type of immune cell) migrate from the ectoderm to interact with the gut epithelium. Bacteria that accumulate in the gut later invade the blastocoel, where they are cleared by phagocytic and granular immune cells. The complexity of this coordinated, dynamic inflammatory program within the simple larval morphology provides a system in which to characterize processes that direct both aspects of the echinoderm-specific immune response as well as those that are shared with other deuterostomes, including vertebrates.

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

    Directory of Open Access Journals (Sweden)

    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

  3. De novo assembly and analysis of tissue-specific transcriptomes revealed the tissue-specific genes and profile of immunity from Strongylocentrotus intermedius.

    Science.gov (United States)

    Chen, Yadong; Chang, Yaqing; Wang, Xiuli; Qiu, Xuemei; Liu, Yang

    2015-10-01

    Strongylocentrotus intermedius is an important marine species in north China and Japan. Recent years, diseases are threating the sea urchin aquaculture industry seriously. To provide a genetic resource for S. intermedius as well as overview the immune-related genes of S. intermedius, we performed transcriptome sequencing of three cDNA libraries representing three tissues, coelomocytes, gut and peristomial membrane respectively. In total 138,421 contigs were assembled from all sequencing data. 96,764 contigs were annotated according to bioinformatics databases, including NT, nr, Swiss-Prot, KEGG, COG. 49,336 Contigs were annotated as CDS. In this study, we obtained 24,778 gene families from S. intermedius transcriptome. The gene expression analysis revealed that more genes were expressed in gut, more high expression level genes in coelomocytes when compared with other tissues. Specific expressed contigs in coelomocytes, gut, and peristomial membrane were 546, 1136, and 1012 respectively. Pathway analysis suggested 25, 17 and 36 potential specifically pathways may specific progressed in peristomial membrane, gut and coelomocytes respectively. Similarities and differences between S. intermedius and other echinoderms were analyzed. S. intermedius was more homology to Strongylocentrotus purpuratus than others sea urchin. Of 24,778 genes, 1074 genes are immune-related, immune genes were expressed with a higher level in coelomocytes than other tissues. Complement system may be the most important immune system in sea urchin. We also identified 2438 SSRs and 16,236 SNPs for S. intermedius. These results provide a transcriptome resource and foundation to study molecular mechanisms of sea urchin immune system. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

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    Roe, J.L.

    1990-01-01

    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 {sup 125}I-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.

  5. Characterization of the deleted in autism 1 protein family: implications for studying cognitive disorders.

    Directory of Open Access Journals (Sweden)

    Azhari Aziz

    2011-01-01

    Full Text Available Autism spectrum disorders (ASDs are a group of commonly occurring, highly-heritable developmental disabilities. Human genes c3orf58 or Deleted In Autism-1 (DIA1 and cXorf36 or Deleted in Autism-1 Related (DIA1R are implicated in ASD and mental retardation. Both gene products encode signal peptides for targeting to the secretory pathway. As evolutionary medicine has emerged as a key tool for understanding increasing numbers of human diseases, we have used an evolutionary approach to study DIA1 and DIA1R. We found DIA1 conserved from cnidarians to humans, indicating DIA1 evolution coincided with the development of the first primitive synapses. Nematodes lack a DIA1 homologue, indicating Caenorhabditis elegans is not suitable for studying all aspects of ASD etiology, while zebrafish encode two DIA1 paralogues. By contrast to DIA1, DIA1R was found exclusively in vertebrates, with an origin coinciding with the whole-genome duplication events occurring early in the vertebrate lineage, and the evolution of the more complex vertebrate nervous system. Strikingly, DIA1R was present in schooling fish but absent in fish that have adopted a more solitary lifestyle. An additional DIA1-related gene we named DIA1-Like (DIA1L, lacks a signal peptide and is restricted to the genomes of the echinoderm Strongylocentrotus purpuratus and cephalochordate Branchiostoma floridae. Evidence for remarkable DIA1L gene expansion was found in B. floridae. Amino acid alignments of DIA1 family gene products revealed a potential Golgi-retention motif and a number of conserved motifs with unknown function. Furthermore, a glycine and three cysteine residues were absolutely conserved in all DIA1-family proteins, indicating a critical role in protein structure and/or function. We have therefore identified a new metazoan protein family, the DIA1-family, and understanding the biological roles of DIA1-family members will have implications for our understanding of autism and mental

  6. Extracellular matrix remodeling and matrix metalloproteinases (ajMMP-2 like and ajMMP-16 like) characterization during intestine regeneration of sea cucumber Apostichopus japonicus.

    Science.gov (United States)

    Miao, Ting; Wan, Zixuan; Sun, Lina; Li, Xiaoni; Xing, Lili; Bai, Yucen; Wang, Fang; Yang, Hongsheng

    2017-10-01

    Remodeling of extracellular matrix (ECM) regulated by matrix metalloproteinases (MMPs) is essential for tissue regeneration. In the present study, we used immunohistochemistry (IHC) techniques against ECM components to reveal changes of ECM during intestine regeneration of Apostichopus japonicus. The expression of collagen I and laminin reduced apparently from the eviscerated intestine, while fibronectin exhibited continuous expression in all regeneration stages observed. Meanwhile, we cloned two MMP genes from A. japonicus by RACE PCR. The full-length cDNA of ajMMP-2 like is 2733bp and contains a predicted open reading frame (ORF) of 1716bp encoding 572 amino acids. The full-length cDNA of ajMMP-16 like is 2705bp and contains an ORF of 1452bp encoding 484 amino acids. The predicted protein sequences of each MMP contain two conserved domains, ZnMc_MMP and HX. Homology and phylogenetic analysis revealed that ajMMP-2 like and ajMMP-16 like share high sequence similarity with MMP-2 and MMP-16 from Strongylocentrotus purpuratus, respectively. Then we investigated spatio-temporal expression of ajMMP-2 like and ajMMP-16 like during different regeneration stages by qRT-PCR and IHC. The expression pattern of them showed a roughly opposite trend from that of ECM components. According to our results, a fibronectin-dominate temporary matrix is created in intestine regeneration, and it might provide structural integrity for matrix and promote cell movement. We also hypothesize that ajMMP-2 like and ajMMP-16 like could accelerate cell migration and regulate interaction between ECM components and growth factors. This work provides new evidence of ECM and MMPs involvement in sea cucumber regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. rab3 mediates cortical granule exocytosis in the sea urchin egg.

    Science.gov (United States)

    Conner, S; Wessel, G M

    1998-11-15

    Egg activation at fertilization in the sea urchin results in the exocytosis of approximately 15,000 cortical granules that are docked at the plasma membrane. Previously, we reported that several integral membrane proteins modeled in the SNARE hypothesis, synaptotagmin, VAMP, and syntaxin, in addition to a small GTPase of the ras superfamily, rab3, were present on cortical granules (Conner, S., Leaf, D., and Wessel, G., Mol. Reprod. Dev. 48, 1-13, 1997). Here we report that rab3 is associated with cortical granules throughout oogenesis, during cortical granule translocation, and while docked at the egg plasma membrane. Following cortical granule exocytosis, however, rab3 reassociates with a different population of vesicles, at least some of which are of endocytic origin. Because of its selective association with cortical granules in eggs and oocytes, we hypothesize that rab3 functions in cortical granule exocytosis. To test this hypothesis, we used a strategy of interfering with rab3 function by peptide competition with its effector domain, a conserved region within specific rab types. We first identified the effector domain sequence in Lytechinus variegatus eggs and find the sequence 94% identical to the effector domain of rab3 in Stronglocentrotus purpuratus. Then, with synthetic peptides to different regions of the rab3 protein, we find that cortical granule exocytosis is inhibited in eggs injected with effector domain peptides, but not with peptides from the hypervariable region or with a scrambled effector peptide. Additionally, effector-peptide-injected eggs injected with IP3 are blocked in their ability to exocytose cortical granules, suggesting that the inhibition is directly on the membrane fusion event and not the result of interference with the signal transduction mechanism leading to calcium release. We interpret these results to mean that rab3 functions in the regulation of cortical granule exocytosis following vesicle docking. Copyright 1998 Academic

  8. Evolutionary change during experimental ocean acidification.

    Science.gov (United States)

    Pespeni, Melissa H; Sanford, Eric; Gaylord, Brian; Hill, Tessa M; Hosfelt, Jessica D; Jaris, Hannah K; LaVigne, Michèle; Lenz, Elizabeth A; Russell, Ann D; Young, Megan K; Palumbi, Stephen R

    2013-04-23

    Rising atmospheric carbon dioxide (CO2) conditions are driving unprecedented changes in seawater chemistry, resulting in reduced pH and carbonate ion concentrations in the Earth's oceans. This ocean acidification has negative but variable impacts on individual performance in many marine species. However, little is known about the adaptive capacity of species to respond to an acidified ocean, and, as a result, predictions regarding future ecosystem responses remain incomplete. Here we demonstrate that ocean acidification generates striking patterns of genome-wide selection in purple sea urchins (Strongylocentrotus purpuratus) cultured under different CO2 levels. We examined genetic change at 19,493 loci in larvae from seven adult populations cultured under realistic future CO2 levels. Although larval development and morphology showed little response to elevated CO2, we found substantial allelic change in 40 functional classes of proteins involving hundreds of loci. Pronounced genetic changes, including excess amino acid replacements, were detected in all populations and occurred in genes for biomineralization, lipid metabolism, and ion homeostasis--gene classes that build skeletons and interact in pH regulation. Such genetic change represents a neglected and important impact of ocean acidification that may influence populations that show few outward signs of response to acidification. Our results demonstrate the capacity for rapid evolution in the face of ocean acidification and show that standing genetic variation could be a reservoir of resilience to climate change in this coastal upwelling ecosystem. However, effective response to strong natural selection demands large population sizes and may be limited in species impacted by other environmental stressors.

  9. A novel MKK gene (AjMKK3/6) in the sea cucumber Apostichopus japonicus: Identification, characterization and its response to pathogenic challenge.

    Science.gov (United States)

    Wang, Yi; Chen, Ge; Li, Kaiquan; Sun, Jingxian; Song, Jian; Zhan, Yaoyao; Zhang, Xiangxiang; Yang, Limeng; Chang, Yaqing

    2017-02-01

    The mitogen-activated protein kinase kinases (MKKs) are key components of MAP kinase (MAPK) cascades and function as redox-regulated signaling factors in pathological and physiological processes. In this study, we identified a novel MKK3/6 gene in the sea cucumber Apostichopus japonicus (designated as AjMKK3/6) by transcriptome database mining and rapid amplification of cDNA ends (RACE) approaches. Sequence analysis and protein structure prediction showed that AjMKK3/6 is highly conserved as compared to those from other invertebrate and vertebrate species. Molecular phylogeny result revealed that AjMKK3/6 exhibited a closest relationship with that from Strongylocentrotus purpuratus. Quantitative real-time PCR was employed to determine the expression profiles of AjMKK3/6 in healthy adult A. japonicus tissues and in coelomocytes after Vibrio splendidus infection in vivo, respectively. As results shown, AjMKK3/6 was ubiquitously expressed in all examined tissues of healthy adult A. japonicus with a relative expression level from high to low as body wall > tube feet > coelomocytes > respiratory tree > intestine > longitudinal muscle. Significant expression changes of AjMKK3/6 in coelomocytes were observed at 12 h- and 72 h-after V. splendidus infection, respectively. In general, the current study will enrich our knowledge of characterizations and immno-functions of MKK3/6 in sea cucumbers. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Oxidative Damage and Cellular Defense Mechanisms in Sea Urchin Models of Aging

    Science.gov (United States)

    Du, Colin; Anderson, Arielle; Lortie, Mae; Parsons, Rachel; Bodnar, Andrea

    2013-01-01

    The free radical or oxidative stress theory of aging proposes that the accumulation of oxidative cellular damage is a major contributor to the aging process and a key determinant of species longevity. This study investigates the oxidative stress theory in a novel model for aging research, the sea urchin. Sea urchins present a unique model for the study of aging due to the existence of species with tremendously different natural life spans including some species with extraordinary longevity and negligible senescence. Cellular oxidative damage, antioxidant capacity and proteasome enzyme activities were measured in the tissues of three sea urchin species: short-lived Lytechinus variegatus, long-lived Strongylocentrotus franciscanus and Strongylocentrotus purpuratus which has an intermediate lifespan. Levels of protein carbonyls and 4-hydroxynonenal (HNE) measured in tissues (muscle, nerve, esophagus, gonad, coelomocytes, ampullae) and 8-hydroxy-2’-deoxyguanosine (8-OHdG) measured in cell-free coelomic fluid showed no general increase with age. The fluorescent age-pigment lipofuscin measured in muscle, nerve and esophagus, increased with age however it appeared to be predominantly extracellular. Antioxidant mechanisms (total antioxidant capacity, superoxide dismutase) and proteasome enzyme activities were maintained with age. In some instances, levels of oxidative damage were lower and antioxidant activity higher in cells or tissues of the long-lived species compared to the short-lived species, however further studies are required to determine the relationship between oxidative damage and longevity in these animals. Consistent with the predictions of the oxidative stress theory of aging, the results suggest that negligible senescence is accompanied by a lack of accumulation of cellular oxidative damage with age and maintenance of antioxidant capacity and proteasome enzyme activities may be important mechanisms to mitigate damage. PMID:23707327

  11. Base excision DNA repair in the embryonic development of the sea urchin, Strongylocentrotus intermedius.

    Science.gov (United States)

    Torgasheva, Natalya A; Menzorova, Natalya I; Sibirtsev, Yurii T; Rasskazov, Valery A; Zharkov, Dmitry O; Nevinsky, Georgy A

    2016-06-21

    In actively proliferating cells, such as the cells of the developing embryo, DNA repair is crucial for preventing the accumulation of mutations and synchronizing cell division. Sea urchin embryo growth was analyzed and extracts were prepared. The relative activity of DNA polymerase, apurinic/apyrimidinic (AP) endonuclease, uracil-DNA glycosylase, 8-oxoguanine-DNA glycosylase, and other glycosylases was analyzed using specific oligonucleotide substrates of these enzymes; the reaction products were resolved by denaturing 20% polyacrylamide gel electrophoresis. We have characterized the profile of several key base excision repair activities in the developing embryos (2 blastomers to mid-pluteus) of the grey sea urchin, Strongylocentrotus intermedius. The uracil-DNA glycosylase specific activity sharply increased after blastula hatching, whereas the specific activity of 8-oxoguanine-DNA glycosylase steadily decreased over the course of the development. The AP-endonuclease activity gradually increased but dropped at the last sampled stage (mid-pluteus 2). The DNA polymerase activity was high at the first cleavage division and then quickly decreased, showing a transient peak at blastula hatching. It seems that the developing sea urchin embryo encounters different DNA-damaging factors early in development within the protective envelope and later as a free-floating larva, with hatching necessitating adaptation to the shift in genotoxic stress conditions. No correlation was observed between the dynamics of the enzyme activities and published gene expression data from developing congeneric species, S. purpuratus. The results suggest that base excision repair enzymes may be regulated in the sea urchin embryos at the level of covalent modification or protein stability.

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

    Science.gov (United States)

    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 during development in these organisms, except that the genes that are involved in the miRNA biogenesis pathway are expressed during their developmental stages. In this paper, we used Illumina Genome Analyzer (Illumina, Inc.) to sequence small RNA libraries in mixed stage population of embryos from one to three days after fertilization of sea urchin and sea star (total of 22,670,000 reads). Analysis of these data revealed the miRNA populations in these two species. We found that 47 and 38 known miRNAs are expressed in sea urchin and sea star, respectively, during early development (32 in common). We also found 13 potentially novel miRNAs in the sea urchin embryonic library. miRNA expression is generally conserved between the two species during development, but 7 miRNAs are highly expressed in only one species. We expect that our two datasets will be a valuable resource for everyone working in the field of developmental biology and the regulatory networks that affect it. The computational pipeline to analyze Illumina reads is available at http://www.benoslab.pitt.edu/services.html. PMID:22216218

  13. Perturbation of gut bacteria induces a coordinated cellular immune response in the purple sea urchin larva

    Science.gov (United States)

    CH Ho, Eric; Buckley, Katherine M; Schrankel, Catherine S; Schuh, Nicholas W; Hibino, Taku; Solek, Cynthia M; Bae, Koeun; Wang, Guizhi; Rast, Jonathan P

    2016-01-01

    The purple sea urchin (Strongylocentrotus purpuratus) genome sequence contains a complex repertoire of genes encoding innate immune recognition proteins and homologs of important vertebrate immune regulatory factors. To characterize how this immune system is deployed within an experimentally tractable, intact animal, we investigate the immune capability of the larval stage. Sea urchin embryos and larvae are morphologically simple and transparent, providing an organism-wide model to view immune response at cellular resolution. Here we present evidence for immune function in five mesenchymal cell types based on morphology, behavior and gene expression. Two cell types are phagocytic; the others interact at sites of microbial detection or injury. We characterize immune-associated gene markers for three cell types, including a perforin-like molecule, a scavenger receptor, a complement-like thioester-containing protein and the echinoderm-specific immune response factor 185/333. We elicit larval immune responses by (1) bacterial injection into the blastocoel and (2) seawater exposure to the marine bacterium Vibrio diazotrophicus to perturb immune state in the gut. Exposure at the epithelium induces a strong response in which pigment cells (one type of immune cell) migrate from the ectoderm to interact with the gut epithelium. Bacteria that accumulate in the gut later invade the blastocoel, where they are cleared by phagocytic and granular immune cells. The complexity of this coordinated, dynamic inflammatory program within the simple larval morphology provides a system in which to characterize processes that direct both aspects of the echinoderm-specific immune response as well as those that are shared with other deuterostomes, including vertebrates. PMID:27192936

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

    Science.gov (United States)

    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

  15. Calbindin-D32k Is Localized to a Subpopulation of Neurons in the Nervous System of the Sea Cucumber Holothuria glaberrima (Echinodermata)

    Science.gov (United States)

    Díaz-Balzac, Carlos A.; Lázaro-Peña, María I.; García-Rivera, Enrique M.; González, Carlos I.; García-Arrarás, José E.

    2012-01-01

    Members of the calbindin subfamily serve as markers of subpopulations of neurons within the vertebrate nervous system. Although markers of these proteins are widely available and used, their application to invertebrate nervous systems has been very limited. In this study we investigated the presence and distribution of members of the calbindin subfamily in the sea cucumber Holothuria glaberrima (Selenka, 1867). Immunohistological experiments with antibodies made against rat calbindin 1, parvalbumin, and calbindin 2, showed that these antibodies labeled cells and fibers within the nervous system of H. glaberrima. Most of the cells and fibers were co-labeled with the neural-specific marker RN1, showing their neural specificity. These were distributed throughout all of the nervous structures, including the connective tissue plexi of the body wall and podia. Bioinformatics analyses of the possible antigen recognized by these markers showed that a calbindin 2-like protein present in the sea urchin Strongylocentrotus purpuratus, corresponded to the calbindin-D32k previously identified in other invertebrates. Western blots with anti-calbindin 1 and anti-parvalbumin showed that these markers recognized an antigen of approximately 32 kDa in homogenates of radial nerve cords of H. glaberrima and Lytechinus variegatus. Furthermore, immunoreactivity with anti-calbindin 1 and anti-parvalbumin was obtained to a fragment of calbindin-D32k of H. glaberrima. Our findings suggest that calbindin-D32k is present in invertebrates and its sequence is more similar to the vertebrate calbindin 2 than to calbindin 1. Thus, characterization of calbindin-D32k in echinoderms provides an important view of the evolution of this protein family and represents a valuable marker to study the nervous system of invertebrates. PMID:22412907

  16. The protein precursors of peptides that affect the mechanics of connective tissue and/or muscle in the echinoderm Apostichopus japonicus.

    Directory of Open Access Journals (Sweden)

    Maurice R Elphick

    Full Text Available Peptides that cause muscle relaxation or contraction or that modulate electrically-induced muscle contraction have been discovered in the sea cucumber Apostichopus japonicus (Phylum Echinodermata; Class Holothuroidea. By analysing transcriptome sequence data, here the protein precursors of six of these myoactive peptides (the SALMFamides Sticho-MFamide-1 and -2, NGIWYamide, stichopin, GN-19 and GLRFA have been identified, providing novel insights on neuropeptide and endocrine-type signalling systems in echinoderms. The A. japonicus SALMFamide precursor comprises eight putative neuropeptides including both L-type and F-type SALMFamides, which contrasts with previous findings from the sea urchin Strongylocentrotus purpuratus where L-type and F-type SALMFamides are encoded by different genes. The NGIWYamide precursor contains five copies of NGIWYamide but, unlike other NG peptide-type neuropeptide precursors in deuterostomian invertebrates, the NGIWYamide precursor does not have a C-terminal neurophysin domain, indicating loss of this character in holothurians. NGIWYamide was originally discovered as a muscle contractant, but it also causes stiffening of mutable connective tissue in the body wall of A. japonicus, whilst holokinins (PLGYMFR and derivative peptides cause softening of the body wall. However, the mechanisms by which these peptides affect the stiffness of body wall connective tissue are unknown. Interestingly, analysis of the A. japonicus transcriptome reveals that the only protein containing the holokinin sequence PLGYMFR is an alpha-5 type collagen. This suggests that proteolysis of collagen may generate peptides (holokinins that affect body wall stiffness in sea cucumbers, providing a novel perspective on mechanisms of mutable connective tissue in echinoderms.

  17. Toxicity of sediment pore water in Puget Sound (Washington, USA): a review of spatial status and temporal trends

    Science.gov (United States)

    Long, Edward R.; Carr, R. Scott; Biedenbach, James M.; Weakland, Sandra; Partridge, Valerie; Dutch, Margaret

    2013-01-01

    Data from toxicity tests of the pore water extracted from Puget Sound sediments were compiled from surveys conducted from 1997 to 2009. Tests were performed on 664 samples collected throughout all of the eight monitoring regions in the Sound, an area encompassing 2,294.1 km2. Tests were performed with the gametes of the Pacific purple sea urchin, Strongylocentrotus purpuratus, to measure percent fertilization success as an indicator of relative sediment quality. Data were evaluated to determine the incidence, degree of response, geographic patterns, spatial extent, and temporal changes in toxicity. This is the first survey of this kind and magnitude in Puget Sound. In the initial round of surveys of the eight regions, 40 of 381 samples were toxic for an incidence of 10.5 %. Stations classified as toxic represented an estimated total of 107.1 km2, equivalent to 4.7 % of the total area. Percent sea urchin fertilization ranged from >100 % of the nontoxic, negative controls to 0 %. Toxicity was most prevalent and pervasive in the industrialized harbors and lowest in the deep basins. Conditions were intermediate in deep-water passages, urban bays, and rural bays. A second round of testing in four regions and three selected urban bays was completed 5–10 years following the first round. The incidence and spatial extent of toxicity decreased in two of the regions and two of the bays and increased in the other two regions and the third bay; however, only the latter change was statistically significant. Both the incidence and spatial extent of toxicity were lower in the Sound than in most other US estuaries and marine bays.

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

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    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

  19. Characterization of the deleted in autism 1 protein family: implications for studying cognitive disorders.

    Science.gov (United States)

    Aziz, Azhari; Harrop, Sean P; Bishop, Naomi E

    2011-01-19

    Autism spectrum disorders (ASDs) are a group of commonly occurring, highly-heritable developmental disabilities. Human genes c3orf58 or Deleted In Autism-1 (DIA1) and cXorf36 or Deleted in Autism-1 Related (DIA1R) are implicated in ASD and mental retardation. Both gene products encode signal peptides for targeting to the secretory pathway. As evolutionary medicine has emerged as a key tool for understanding increasing numbers of human diseases, we have used an evolutionary approach to study DIA1 and DIA1R. We found DIA1 conserved from cnidarians to humans, indicating DIA1 evolution coincided with the development of the first primitive synapses. Nematodes lack a DIA1 homologue, indicating Caenorhabditis elegans is not suitable for studying all aspects of ASD etiology, while zebrafish encode two DIA1 paralogues. By contrast to DIA1, DIA1R was found exclusively in vertebrates, with an origin coinciding with the whole-genome duplication events occurring early in the vertebrate lineage, and the evolution of the more complex vertebrate nervous system. Strikingly, DIA1R was present in schooling fish but absent in fish that have adopted a more solitary lifestyle. An additional DIA1-related gene we named DIA1-Like (DIA1L), lacks a signal peptide and is restricted to the genomes of the echinoderm Strongylocentrotus purpuratus and cephalochordate Branchiostoma floridae. Evidence for remarkable DIA1L gene expansion was found in B. floridae. Amino acid alignments of DIA1 family gene products revealed a potential Golgi-retention motif and a number of conserved motifs with unknown function. Furthermore, a glycine and three cysteine residues were absolutely conserved in all DIA1-family proteins, indicating a critical role in protein structure and/or function. We have therefore identified a new metazoan protein family, the DIA1-family, and understanding the biological roles of DIA1-family members will have implications for our understanding of autism and mental retardation.

  20. Multitasking Immune Sp185/333 Protein, rSpTransformer-E1, and Its Recombinant Fragments Undergo Secondary Structural Transformation upon Binding Targets.

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    Lun, Cheng Man; Bishop, Barney M; Smith, L Courtney

    2017-04-01

    The purple sea urchin, Strongylocentrotus purpuratus , expresses a diverse immune response protein family called Sp185/333. A recombinant Sp185/333 protein, previously called rSp0032, shows multitasking antipathogen binding ability, suggesting that the protein family mediates a flexible and effective immune response to multiple foreign cells. Bioinformatic analysis predicts that rSp0032 is intrinsically disordered, and its multiple binding characteristic suggests structural flexibility to adopt different conformations depending on the characteristics of the target. To address the flexibility and structural shifting hypothesis, circular dichroism analysis of rSp0032 suggests that it transforms from disordered (random coil) to α helical structure. This structural transformation may be the basis for the strong affinity between rSp0032 and several pathogen-associated molecular patterns. The N-terminal Gly-rich fragment of rSp0032 and the C-terminal His-rich fragment show unique transformations by either intensifying the α helical structure or changing from α helical to β strand depending on the solvents and molecules added to the buffer. Based on these results, we propose a name change from rSp0032 to rSpTransformer-E1 to represent its flexible structural conformations and its E1 element pattern. Given that rSpTransformer-E1 shifts its conformation in the presence of solvents and binding targets and that all Sp185/333 proteins are predicted to be disordered, many or all of these proteins may undergo structural transformation to enable multitasking binding activity toward a wide range of targets. Consequently, we also propose an overarching name change for the entire family from Sp185/333 proteins to SpTransformer proteins. Copyright © 2017 by The American Association of Immunologists, Inc.

  1. Proteomic profiles reveal age-related changes in coelomic fluid of sea urchin species with different life spans.

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    Bodnar, Andrea

    2013-05-01

    Sea urchins have a different life history from humans and traditional model organisms used to study the process of aging. Sea urchins grow indeterminately, reproduce throughout their life span and some species have been shown to exhibit negligible senescence with no increase in mortality rate at advanced ages. Despite these properties, different species of sea urchins are reported to have very different natural life spans providing a unique model to investigate cellular mechanisms underlying life span determination and negligible senescence. To gain insight into the biological changes that accompany aging in these animals, proteomic profiles were examined in coelomic fluid from young and old sea urchins of three species with different life spans: short-lived Lytechinus variegatus, long-lived Strongylocentrotus franciscanus and Strongylocentrotus purpuratus which has an intermediate life span. The proteomic profiles of cell-free coelomic fluid were complex with many proteins exhibiting different forms and extensive post-translational modifications. Approximately 20% of the protein spots on 2-D gels showed more than two-fold change with age in each of the species. Changes that are consistent with age in all three species may prove to be useful biomarkers for age-determination for these commercially fished marine invertebrates and also may provide clues to mechanisms of negligible senescence. Among the proteins that change with age, the ectodomain of low-density lipoprotein receptor-related protein 4 (LRP4) was significantly increased in the coelomic fluid of all three sea urchin species suggesting that the Wnt signaling pathway should be further investigated for its role in negligible senescence. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Variabilidade diária da zonação da macrofauna bentônica em praias arenosas do litoral norte do Rio Grande do Sul Daily zonation variation of sandy beach benthic macrofauna in north coast of the Rio Grande do Sul, Brazil

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    Frederico Monteiro Neves

    2009-03-01

    Full Text Available O objetivo deste trabalho é verificar a variação diária da zonação da macrofauna bentônica nas praias de Tramandaí, Harmonia e Jardim do Éden, Rio Grande do Sul. As coletas foram feitas ao longo de cinco dias consecutivos, utilizando-se um tubo de PVC de 20 cm de diâmetro. Foram demarcadas três transversais distantes 50 m uma da outra, com 4 estações de coleta e três amostras cada. As estações se estenderam desde 8 m acima do limite superior da zona de varrido (definida a cada dia até 1 m de profundidade. Também foram coletados diariamente dados dos perfis topográficos de cada praia. Os resultados mostraram que a macrofauna bentônica apresenta um padrão de zonação regular ao longo dos dias. O intermareal foi marcado pela presença do isópode Excirolana armata (Dana, 1853 e do poliqueta Euzonus furciferus (Ehlers, 1897. A zona de varrido apresentou grande abundância do caranguejo hipídeo Emerita brasiliensis (Schmitt, 1935, do bivalvo Donax hanleyanus (Philippi, 1842 e do poliqueto Scolelepis gaucha (Orensanz & Gianuca, 1974. As zonas de "surf" e arrebentação interna não apresentaram diferenças na composição de espécies, sendo dominantes os juvenis de D. hanleyanus, Mesodesma mactroides (Deshayes, 1854, o anfípode Phoxocephalopsis zimmeri (Schellenberg, 1931, o poliqueto Hemipodus olivieri (Orensanz & Gianuca, 1974, além do bivalve Donax gemmula (Morrison, 1971. Os resultados indicaram que, apesar do padrão de zonação da macrofauna ter sido regular ao longo do estudo, algumas mudanças na posição vertical das espécies foram observadas, principalmente em função da variação da zona de varrido.This work verified the daily zonation of benthic macrofauna in Tramandaí, Harmonia and Jardim do Éden beaches, north coast of the state of Rio Grande do Sul, southern Brazil, for five consecutive days. Biological data were collected with a PVC core (20 cm diameter along three transects distant 50 m of each other

  3. Distribución geográfica y depredación de Porites lobata (Anthozoa: Scleractinia en la costa occidental de México

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    Héctor Reyes Bonilla

    1999-06-01

    Full Text Available El coral hermatípico Porites lobata Dana, 1846 es, una de las especies más importantes en las comunidades arrecifales de América Central, pero fue registrada en México hasta 1992, en el Archipiélago de Revillagigedo. El objetivo del presente trabajo fue el de dar a conocer la distribución geográfica y algunos aspectos de la biología de P. lobata en la costa occidental de México, a partir de observaciones de campo y datos de literatura. Esta especie se distribuye en México dentro de un segmento de costa de aproximadamente 200 km, desde Nayarit (20° N hasta Colima (19° N, y en las Islas Revillagigedo (18° N; P. lobata no aparece en el Golfo de Califomia (23° a 30° N, o en comunidades coralnas situadas de los 17° N a los 15° N. Su distribución disjunta puede ser explicada tomando en cuenta que el emisor larval hacia el continente deben ser las Revillagigedo, utilizando la Contracorriente Norecuatorial como mecanismo de transporte y dispersión. Comparando las comunidades coralinas donde ha sido localizado, P. lobata era mucho más abundante en las Revillagigedo que en el continente. Sin embargo, los daños causados por los dedepredadores parecen ser mayores en Nayarit- Jalisco- Colima que en las islas oceánicas, quizá debido a que los peces coralívoros son poco comunes allí. La densidad poblacional de los bioerosionadores (esponjas, poliquetos, sipuncúlidos y bivalvos fue similar y a veces mayor en las colonias de P. lobata de las Revillagigedo que en aquellas de la costa continental, lo que sugiere la posibilidad de que haya un diferencial en la productividad primaria de esas localidades.The hermatypic coral Porites lobata Dana, 1846 is one of the most important species in Central American reef communities, recorded in México only in 1992, at the Revillagigedo Archipelago. This paper describes the geographic distribution and predation pressure on P. lobata in the west coast of México, based on field observations and

  4. Organismos de un arrecife fósil (Oligoceno Superior-Mioceno Inferior, del Caribe de Costa Rica

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    Teresita Aguilar Alvarez

    1999-09-01

    Full Text Available En la localidad de Jesús María, Turrialba, afloran de 12-30 m de calizas arrecifales, areniscas y conglomerados de edad Oligocena Superior-Miocena Inferior, que se asocian con la Formación Punta Pelada. En ésta localidad se registra una de las primeras comunidades arrecifales de la actual región Caribe de Costa Rica y constituye una de las pocas localidades de arrecifes de ésta edad en el área. Los afloramientos se interpretan como parches arrecifales debido a su distribución irregular y a su poca extensión lateral (50m, los cuales se desarrollaron bajo la influencia de diversos procesos: variación en la energía del medio, cambios en el nivel del mar, plataformas angostas, excesiva sedimentación clástica posiblemente desde islas. Se analizaron 460 ejemplares, los cuales corresponden a más de 36 especies, que permitieron hacer una recosnstrucción de la estructura y de las condiciones ambientales en que se desarrollaron. Los arrecifes constituyeron comunidades de baja diversidad: cuatro especies de corales (tres de constructores, 31 especies de moluscos (21 de Gastrópodos: una especie nueva, 14 de carnívoros, tres de herbívoros, tres de hábitos alimenticios desconocidos; 10 especies de Bivalvos: cinco endobentónicos, cinco epibentónicos, algas (representantes de por lo menos tres grupos, equinodermos, foraminíferos, crustáceos. La equidad también es muy baja, principalmente en lo referente a los corales Scleractinia, con un predominio muy marcado de Antiguastrea celullosa (80% de las formas encontradas. Esto permite inferir que se desarrollaron en un ambiente de poca profundidad (50-80 m, muy variable, con influencia ocasional de corrientes marinas fuertes y aporte de sedimentos terrígenos procedentes de islas cercanas.This paper describes the fossils, materials and paleoenvironmental conditions found in some outcrops near the town of Jesús María, Turrialba, Costa Rica. The rock materials (reefal limestone, sandstones

  5. The reproductive biology of Lutraria philippinarum (Veneroida: Mactridae and its fishery in the Philippines

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    Venus Bantoto

    2012-12-01

    Full Text Available The Snout Otter Clam, Lutraria philippinarum is a regularly harvested bivalve species for food and also as a source of income in the Philippines. For sustainable supply of this resource in the wild, efficient and effective management strategies are needed, and the evaluation of its reproductive biology and fishery are required. In this study, the reproductive biology and fishery of L. philippinarum in the Philippines were examined monthly from January to December 2010 in North Bais Bay, Manjuyod, Negros Oriental and Philippines. For reproductive biology, otter clams were sampled, and sex ratio (by microscopic observation, size at sexual maturity, shell length (with a vernier caliper, gonad development (by histological examination as resting, developing, mature, spawning and spent and spawning season were determined. Other information such as water temperature, salinity, pH and dissolved oxygen were also measured. To obtain information on the L. philippinarum fishery, interviews were conducted in Negros Oriental, Bohol, Cebu and Sarangani. A total of 677 snout otter clams were sampled. The study showed that L. philippinarum sex ratio was 1:1.15 and showed no significant difference from 1:1 ratio. Males attained its first sexual maturity at 43mm shell length while the females at 46mm. Histological examination on gonad development indicated that gametogenesis, maturation and spawning season of L. philippinarum occurred throughout the year with two spawning peaks, January and June. Changes in water temperature in North Bais Bay may have influenced the spawning peaks of L. philippinarum. Data on the fishery of L. philippinarum revealed that the Catch Per Unit Effort of L. philippinarum in the Philippines ranged from 0.2kg/hr-man to 1.25kg/hr-man suggesting low shell catch. We recommend that some mature individuals have to be left in the population to allow in situ breeding.Lutraria philippinarum es una especie de bivalvo recolectada regularmente para

  6. Genetic composition of Mytilus species in mussel populations from southern Chile Composición genética de especies de Mytilus en poblaciones de mejillón del sur de Chile

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    María Angélica Larraín

    2012-11-01

    Full Text Available Mussels are one of the most cultivated and commercialized bivalves worldwide and in southern Chile its culture represent an important economic activity. The species identification within the Mytilus genera, by morphological features, is unreliable, so we used a polymorphism RFLP in the gene encoding the polyphenolic adhesive protein as a species-specific genetic marker to describe Mytilus species diversity in southern Chile, and evaluate possible applications in traceability, food quality and safety. Using Me 15-16 marker most mussels were M. chilensis, finding no other pure individuals; however, putative hybrids of M. chilensis x M. trossulus and M. chilensis x M. galloprovincialis were detected. There was no evidence of M. edulis. The presence of the M. trossulus allele, faraway from its distribution area, demands further analysis with different genetic markers to allow a better understanding of its origin. In addition, the correspondence between markers that distinguishes northern from southern hemisphere M. galloprovincialis, with those who discriminates between M. chilensis and M. galloprovincialis would contribute to the taxonomic status of Chilean blue mussels. In Chile, the genetic composition of Mytilus indicates that geographical origin of mussels and its traceability cannot be established merely from the identification of the species. The use of other markers would be required.Los mejillones son una de las especies de bivalvos más cultivadas y comercializadas, en el sur de Chile donde su cultivo representa una actividad económica importante. La identificación de la especie dentro del género Mytilus, basada en las características morfológicas no es confiable por lo que se utilizó un polimorfismo RFLP en el gen que codifica la proteína adhesiva polifenólica como marcador genético específico de la especie para describir la diversidad de especies Mytilus en el sur de Chile, y evaluar posibles aplicaciones en trazabilidad

  7. Efecto de bacterias probióticas en el cultivo larvario del ostión de placer Crassostrea corteziensis (Bivalvia: Ostreidae

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    Angel Isidro Campa-Córdova

    2011-03-01

    Full Text Available El ostión de placer u ostra del Cortés (Crassostrea corteziensis se considera como una especie con potencial para ser cultivada en gran escala. Sin embargo, al igual que en otros bivalvos, la alta mortalidad que se presenta durante la etapa larvaria y juvenil, es el principal problema que limita el desarrollo del cultivo en el laboratorio. Un método que está ganando aceptación en la acuicultura es el uso de bacterias probióticas para controlar patógenos microbianos. Este estudio analiza el efecto de estas bacterias en la supervivencia y talla final de larvas de ostión de placer Crassostrea corteziensis. Se utilizó una cepa de bacterias ácido lácticas (cepa NS61 aisladas N. subnodosus, así como de bacilos aislados de L. vannamei (Pseudomonas aeruginosa, cepa YC58 y de C. corteziensis (Burkholderia cepacia, cepa Y021. Las cepas se evaluaron por inmersión en cultivos larvarios de C. corteziensis a dos concentraciones diferentes, hasta completar el estadio pediveliger. Los organismos se trataron con bacterias ácido lácticas (Lb, una mezcla de bacilos (Lb en proporción 1:1 y un grupo control. La concentración de 1x10(4UFC/ml registró una mayor supervivencia con Lb y Mb respecto al grupo control. La supervivencia con Mb a una concentración de 1x10(5UFC/ml fue mayor que la del grupo control y del grupo tratado con Lb. Los resultados mostraron que las larvas de C. corteziensis tratadas con probióticos no incrementaron significativamente su talla respecto a las larvas del grupo control. Mientras que las tratadas con Lb a la concentración mayor, 1x10(5UFC/ml, mostraron una disminución de la supervivencia respecto a las tratadas con 1x10(4UFC/ml. Este estudio demostró el efecto benéfico de cepas probióticas utilizadas individualmente o en mezcla en el cultivo larvario de C. corteziensis.Effect of probiotic bacteria on survival and growth of Cortez oyster larvae, Crassostrea corteziensis (Bivalvia: Ostreidae. Disease control

  8. Revision of the Mio-Pliocene bunodont otter-like mammals of the Indian Subcontinent

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    Pickford, M.

    2007-06-01

    Full Text Available A revision of the Enhydriodontini of the Indian Subcontinent is undertaken on the basis of previously described and recently collected bunodont otter-like fossils from the sub-Himalayan Siwalik Group. It is confirmed that, with the passage of geological time spanning the period 13 – 3 Ma, there occurred a progressive increase in body size, a reduction of the anterior part of the premolar row and an increase in degree of cheek tooth bunodonty and cusp mastoidization. Functional analysis of a snout with a partly preserved incisor battery of Enhydriodon sivalensis, reveals that it was probably a molluscivore, preying principally on bivalves, while other species of enhydriodonts were more likely to have been piscivores and cancrivores. One new species of Sivaonyx is described from the base of the Late Miocene of Pakistan. Bunodont otter-like mammals from Eurasia, Africa and North America are briefly discussed in light of the revision of the Indo-Pakistan ones. The origins and phylogenetic relationships of these mammals remains obscure. The major differences in dental anatomy indicate that these Old World otter-like mammals should not be classified in Enhydrini, but in a tribe of their own Enhydriodontini new tribe.La revisión de los Enhydriontinos del subcontinente Indio se aborda, tanto en base a los fósiles de nutrias bunodontas previamente descritos, como a los hallazgos recientemente realizados en el Grupo de los Siwaliks en el sub-Himalaya. Se confirma que durante el período de tiempo comprendido entre los 13 a 3 Ma hubo un progresivo incremento en la talla corporal, una reducción de la parte anterior de la serie premolar y un incremento en el grado de bunodoncia y mastoidización de las cúspides de los dientes. El análisis funcional de un hocico de Enhydriodon sivalensis con la batería de incisivos parcialmente conservados revela que esta especie fue parcialmente malacófaga, alimentándose principalmente de bivalvos, mientras que

  9. Diversidad y biomasa de macro-invertebrados en matrices intermareales del tunicado Pyura praeputialis (Heller, 1878 en la Bahía de Antofagasta, Chile Diversity and biomass of macro-invertebrates in intertidal matrices of the tunicate Pyura praeputialis (Heller, 1878 in the Bay of Antofagasta, Chile

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    MAURICIO CERDA

    2001-12-01

    Full Text Available Se analiza la diversidad biológica y biomasa de macro-invertebrados asociados a los mantos intermareales del tunicado Pyura praeputialis (Heller, 1878 en la Bahía de Antofagasta, donde la especie se encuentra casi exclusivamente confinada a lo largo de aproximadamente 70 km de extensión costera de dicha bahía. En la bahía se seleccionaron tres sitios para el análisis de los mantos de piures: uno localizado aproximadamente en el centro de la distribución del tunicado y dos cercanos a los límites norte y sur (ecotonos de dicha distribución. La arquitectura de las matrices de piures genera substrato secundario y bio-hábitat que corresponden a los de una especie bio-ingeniera ecosistémica. En las matrices se encontró una diversidad gama de 96 taxa de macro-invertebrados, pertenecientes a nueve phyla. Entre ellos destaca la riqueza de gastrópodos (28 %, poliquetos (26 %, decápodos (15 % y bivalvos (14 %. Para los macro-invertebrados se registró una biomasa promedio de 246,40 g m-2 . Los atributos de diversidad y biomasa de macro-invertebrados no presentaron diferencias significativas entre sitios, lo cual sugiere que el efecto de estas matrices sobre la diversidad y biomasa de los macro-invertebrados es similar a lo largo del rango de distribución dentro de la bahía. Los resultados son discutidos en términos de los patrones de biodiversidad de macro-invertebrados, sus biomasas y el rol que juega P. praeputialis como especie bio-ingeniera en la zona costera de la Bahía de Antofagasta. Se realizan comparaciones con un estudio similar realizado en mantos de Pyura stolonifera en Natal, Sudáfrica y respecto de la biodiversidad de invertebrados asociadas a otras especies bio-ingenierasThe study was conducted to analyze the biological diversity and biomass of macro-invertebrates in intertidal matrices of Pyura praeputialis (Heller, 1878 in the Bahía de Antofagasta, where the species is confined along approximately 70 km of coastline

  10. Ciclo gonadal del chorito Mytilus chilensis (Bivalvia: Mytilidae en dos localidades del sur de Chile Gonadal cycle of the mussel Mytilus chilensis (Bivalvia: Mytilidae at two localities in southern of Chile

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    Pablo A Oyarzún

    2011-11-01

    Full Text Available Se analizó de forma cualitativa y cuantitativa el ciclo gonadal del bivalvo Mytilus chilensis en las localidades de Chaihuín y bahía Yal, sur de Chile, entre octubre 2007 y junio 2008. Por medio de análisis histológico gonadal se determinaron cuatro estadios gametogénicos y a su vez se estimó en forma cuantitativa, el Volumen de la Fracción Gamética (VFG, el porcentaje de tejido interfolicular y el índice gonadal. El análisis cuantitativo (VFG fue el mejor indicador para determinar los desoves. En los ejemplares de Chaihuín se observaron dos eventos de emisión gamética en forma simultánea en ambos sexos, que ocurrieron en octubre y marzo. Sin embargo, en los ejemplares de bahía Yal se registraron cuatro desoves, principalmente de marzo a junio (otoño, cuando la temperatura del agua disminuyó. Se determinó una escasa relación entre el Índice Gonadosomático (IG y los estadios gametogénicos, al igual que entre el IG y el porcentaje de ovocitos maduros, por ende el IG no sería un indicador apropiado para los desoves en esta especie. Se sugiere la revisión del periodo de veda de Mytilus chilensis (1 noviembre a 31 diciembre, ya que la mayor parte de los individuos de las poblaciones estudiadas, maduran principalmente en octubre. En ambas localidades, el porcentaje de tejido conjuntivo de los especímenes estudiados fluctúo entre 15 y 70% de cobertura gonadal. Los resultados obtenidos mostraron diferencias en los ciclos reproductivos de Mytilus chilensis entre las localidades analizadas, las que se podrían atribuir a diferencias ambientales (e.g. temperatura causadas por el gradiente latitudinal.A qualitative and quantitative analysis was carried out of the gonadal cycle of the bivalve Mytilus chilensis from Chaihuín and Yal bay, southern Chile, between October 2007 and June 2008. Four gametogenic stages were determined using histological analysis of the gonads, and quantitative estimates were made of the Gametic Volume

  11. Centrocestus formosanus (Opisthorchiida: Heterophyidae como causa de muerte de alevines de tilapia gris Oreochromis niloticus (Perciforme: Cichlidae en el Pacífico seco de Costa Rica

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    Donald Arguedas Cortés

    2010-12-01

    Full Text Available Centrocestus formosanus es un parásito trematodo zoonótico originario de Asia asociado con muertes de peces principalmente de cultivo. 907 moluscos provenientes de estanques sembrados con tilapias, seleccionados uno por provincia fueron identificados al nivel taxonómico especifico. Se identificaron cuatro gastrópodos y un bivalvo: M. tuberculata, M. turricula, P. flagellata, H. cubensis y A. luteola. Se reporta, por primera vez, la presencia de dos especies de moluscos en Costa Rica. Se identificaron siete morfotipos de cercarias parasitando las cinco especies de moluscos encontradas. En la segunda exposición experimental se demostró que el morfotipo parapleurolofocercus encontrado en M. tuberculata concuerda con el hallazgo de C. formosanus en alevines de tilapia, después del examen clínico, anatomopatológico y parasitológico realizado a los alevines expuestos. Las metacercarias fueron extraídas del quiste utilizando microagujas y micropinzas lavadas en solución salina fisiológica (0.65%, fijadas en formol caliente al 4% y después esquematizadas con una cámara clara adaptada a un microscopio fotónico, estimándose una abundancia e intensidad media de 1018-1027 digeneos por branquia en cada pez parasitado, determinándose así el hospedador intermediario primario y secundario del parásito. En el presente trabajo se reporta por primera vez Centrocestus formosanus en Costa Rica.Centrocestus formosanus (Opisthorchiida: Heterophyidae as a cause of death in gray tilapia fry Oreochromis niloticus (Perciforme: Cichlidae in the dry Pacific of Costa Rica. Centrocestus formosanus is a zoonotic trematode from Asia and has been mainly associated as cause of death of cultured fish. To identify pathogen trematode species in tilapia fry (Oreochromis niloticus and to determine mollusks hosting these parasites, freshwater mollusks were collected from tilapia cultured ponds and experimental infections were carried out with tilapia fries and

  12. First records of freshwater molluscs from the ecological reserve El Edén, Quintana Roo, México Primeros registros de moluscos dulceacuícolas de la Reserva Ecológica El Edén, Quintana Roo, México

    Directory of Open Access Journals (Sweden)

    Roberto Cózatl-Manzano

    2007-12-01

    Full Text Available The diversity of the freshwater molluscs at El Edén was unknown. This is the first treatment of them, allowing us to compare spatial and temporal species distribution. Eleven species of freshwater molluscs were found in 2 surveys carried in March (dry season and September (rainy season 1998 at the reserve El Edén. A total of 266 individuals were collected; 8 pulmonates, Mayabina spiculata, Mexinauta impluviatus, Physa sp., Biomphalaria havanensis, Drepanotrema lucidum, Drepanotrema kermatoides, Planorbella (Pierosoma trivolvis, and Planorbula armigera; 2 prosobranchs, Pyrgophorus sp. and Pomacea flagellata; and one bivalve, Musculium transversum. Pulmonata dominate over Prosobranchia species in diversity. No significant differences were observed in diversity between dry and rainy seasons. However, species abundance recorded in both seasons was very low, probably due to a combination of inadequate food resources and disadvantageous climate (periodic conditions of drought and flooding. Further studies using a combination of different sampling methods and more frequent samplings are needed to confirm or identify these factors. We suggest that future studies should focus on cultivation of species with economic potential such as the apple snail Pomacea flagellata.La diversidad de moluscos dulceacuícolas de la Reserva Ecológica El Edén se desconocía; este estudio constituye su primer registro. Asimismo, esta investigación permite comparar la distribución espacial y temporal de las especies registradas. Las recolectas se efectuaron en marzo (temporada de sequía y septiembre (lluvia de 1998. Se registran 11 especies (266 individuos en total, 8 pulmonados: Mayabina spiculata, Mexinauta impluviatus, Physa sp., Biomphalaria havanensis, Drepanotrema lucidum, Drepanotrema kermatoides, Planorbella (Pierosoma trivolvis y Planorbula armigera; dos prosobranquios: Pyrgophorus sp. y Pomacea flagellata, y un bivalvo: Musculium transversum. Los pulmonados

  13. Metalotioninas en Perna viridis (Bivalvia: Mytilidae: variación estacional y su relación con la biología reproductiva Metallothioneins in Perna viridis (Bivalvia: Mytilidae: seasonal variation and its relation to reproductive biology

    Directory of Open Access Journals (Sweden)

    Mairin Lemus

    2013-06-01

    Full Text Available Las metalotioninas (Mts son proteínas de baja masa molecular que juegan un rol importante en la detoxificación de metales, en vista de su papel ecotoxicológico se evaluaron las metalotioneínas (MTs en 350 ejemplares del bivalvo Perna viridis en dos localidades de la costa norte del estado Sucre, desde febrero hasta diciembre 2003. Se determinaron los índices biométricos: índice de condición (IC, rendimiento de carne (RC y relación peso seco-talla (PSL. Las Mts fueron separadas por cromatografía de exclusión molecular, Sephadex G-50 y se cuantificaron por saturación con cadmio. Los índices biométricos (RC y PSL mostraron variaciones estacionales, entre localidades y estados de madurez, con la excepción del CI. No se encontraron diferencias significativas entre sexos. Las Mts mostraron variaciones estacionales, con concentraciones más elevadas entre febrero y marzo y mínimos entre septiembre y diciembre, que coincidieron con los períodos de alta y baja productividad en el área, respectivamente. Los mejillones de Río Caribe presentaron una mayor concentración de Mts que los de Chacopata. Los mejillones inmaduros mostraron la mayor concentración de Mts y la más baja en los desovados. Se encontró una relación negativa y significativa entre Mts y CI. Los resultados demuestran que las Mts de Perna viridis están influidas por el índice de condición y la condición reproductiva, asi como también pot los factores físico-químicos del ambiente marino.Metallothionein is a cytosolic protein found in a variety of tissues and have been involved in the regulation of essential trace metals such as copper and zinc, and in the detoxification of essential and nonessential metals. With the aim to study their seasonal variation and their possible role in reproductive behavior, we evaluated metallothioneins (Mts in Perna viridis, taken from Rio Caribe and Chacopata localities in the North coast of Sucre state, Venezuela. A total of 325

  14. Benthic communities associated to Thalassia testudinum (Hydrocharitaceae at three localities of Morrocoy National Park, Venezuela

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    Ricardo Bitter - Soto

    1999-09-01

    Full Text Available The benthic community associated with the turtlegrass Thalassia testudinum beds was analized at three localities of Morrocoy National Park, Venezuela. The localities were selected according to their exposure to the open sea : A (protected, B (intermediate and C (exposed. At each locality, a 20 x 20 m area was randomly chosen, delimited and divided into 400 1x1 m quadrats. Inside each, ten randomly selected quadrats/month were sampled during 13 consecutive months. At each site all macroinvertebrates and several physical variables were recorded, as well as leaf and rhizome biomass of T. testudinum. All parameters had a step- wise gradient from A through C: organic matter, carbon nitrogen, oxygen, salinity and temperature gradient was: ABC. Percentages of sand, silt and clay showed an inverse gradient; ASe analizó la comunidad bentónica asociada a Thalassia testudinum y su relación con algunos parámetros bióticos y abióticos, en tres localidades del Parque Nacional Morrocoy, Falcón-Venezuela; éstas fueron seleccionadas de acuerdo al grado de exposición al mar abierto: A(protegída, B (intermedia y C (expuesta. En cada localidad se demarcó un área de 20 x 20m, se muestrearon aleatoriamente 10cuadrantes/mes, (130 cuadrantes/localidad. Se efectuaron registros de oxígeno disuelto, salinidad, temperatura, porcentajes de materia orgánica, carbono y nitrógeno, textura del sedimento, biomasa foliar y de rizoma de T. testudinum. Todos los parámetros analizados presentaron un gradiente escalonado. Materia Orgánica, Carbono y Nitrógeno, Oxígeno disuelto, Salinidad y Temperatura presentaron el gradiente: ABC. Los porcentages de Arena, Limo y Arcilla presentaron un gradiente inverso. El patrón en la Diversidad, Equidad y Dominancia fue: BCA. La fauna colectada estuvo compuesta por los grupos: Coelenterata (Anthozoa, Polichaeta, Sipuncula, Molusca, Crustacea y Echinodermata. Se identificaron 15 especies de moluscos (gastrópodos y bivalvos, (3

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

    Science.gov (United States)

    Davidson, Eric H.; Rast, Jonathan P.; Oliveri, Paola; Ransick, Andrew; Calestani, Cristina; Yuh, Chiou-Hwa; Minokawa, Takuya; Amore, Gabriele; Hinman, Veronica; Arenas-Mena, Cesar; hide

    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

  16. Identification of a major polypeptide component of the sea urchin fertilization envelope.

    Science.gov (United States)

    Vater, C A; Jackson, R C

    1989-03-01

    A monoclonal antibody (MAb No. 25-16), raised against purified cortical secretory vesicles (CVs) from the eggs of Strongylocentrotus purpuratus, has been used to identify a previously uncharacterized CV-derived polypeptide component of the sea urchin fertilization envelope (FE). MAb No. 25-16, an IgG1, bound to a group of proteins with Mr approximately 200,000 on immunoblots of CVs. This same group of proteins also was detected in fertilization product and in soft FEs prepared from early embryos, indicating that the antigen is released at fertilization by CV exocytosis and becomes incorporated into the FE. The multiple components recognized by MAb No. 25-16 apparently did not result from proteolysis during sample preparation or differential N-linked glycosylation. No simplification of the SDS-gel or immunoblot patterns was observed when samples of fertilization product or cell surface complex were prepared in the presence of a cocktail of protease inhibitors; nor was a change in mobility of any of the antigen forms detected following treatment with endoglycosidase F. Upon partial denaturation and reduction of the protein by incubation at room temperature in the presence of SDS and dithiothreitol, the antigen was shown to undergo a decrease in relative mobility on SDS-PAGE. Complete reduction and denaturation, by boiling in dithiothreitol-containing SDS sample buffer or by an on-blot reduction technique, resulted in loss of the epitope. The protein component recognized by MAb No. 25-16 underwent a striking increase in mobility on SDS-PAGE after chelation of calcium ions with EGTA. Immunogold labeling on thin sections of unfertilized eggs revealed that the antigen is located in the spiral lamellar cores of all CVs. In fertilized eggs, fixed 5 min after insemination, the antigen was detected in the FE. Based on these biochemical and immunological data, we suggest that the antigen recognized by MAb No. 25-16 is released exocytotically from the CVs into the

  17. Molecular evolution of the reactive oxygen-generating NADPH oxidase (Nox/Duox family of enzymes

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    Lambeth J David

    2007-07-01

    Full Text Available Abstract Background NADPH-oxidases (Nox and the related Dual oxidases (Duox play varied biological and pathological roles via regulated generation of reactive oxygen species (ROS. Members of the Nox/Duox family have been identified in a wide variety of organisms, including mammals, nematodes, fruit fly, green plants, fungi, and slime molds; however, little is known about the molecular evolutionary history of these enzymes. Results We assembled and analyzed the deduced amino acid sequences of 101 Nox/Duox orthologs from 25 species, including vertebrates, urochordates, echinoderms, insects, nematodes, fungi, slime mold amoeba, alga and plants. In contrast to ROS defense enzymes, such as superoxide dismutase and catalase that are present in prokaryotes, ROS-generating Nox/Duox orthologs only appeared later in evolution. Molecular taxonomy revealed seven distinct subfamilies of Noxes and Duoxes. The calcium-regulated orthologs representing 4 subfamilies diverged early and are the most widely distributed in biology. Subunit-regulated Noxes represent a second major subdivision, and appeared first in fungi and amoeba. Nox5 was lost in rodents, and Nox3, which functions in the inner ear in gravity perception, emerged the most recently, corresponding to full-time adaptation of vertebrates to land. The sea urchin Strongylocentrotus purpuratus possesses the earliest Nox2 co-ortholog of vertebrate Nox1, 2, and 3, while Nox4 first appeared somewhat later in urochordates. Comparison of evolutionary substitution rates demonstrates that Nox2, the regulatory subunits p47phox and p67phox, and Duox are more stringently conserved in vertebrates than other Noxes and Nox regulatory subunits. Amino acid sequence comparisons identified key catalytic or regulatory regions, as 68 residues were highly conserved among all Nox/Duox orthologs, and 14 of these were identical with those mutated in Nox2 in variants of X-linked chronic granulomatous disease. In addition to

  18. The SpTransformer Gene Family (Formerly Sp185/333 in the Purple Sea Urchin and the Functional Diversity of the Anti-Pathogen rSpTransformer-E1 Protein

    Directory of Open Access Journals (Sweden)

    L. Courtney Smith

    2017-06-01

    Full Text Available The complex innate immune system of sea urchins is underpinned by several multigene families including the SpTransformer family (SpTrf; formerly Sp185/333 with estimates of ~50 members, although the family size is likely variable among individuals of Strongylocentrotus purpuratus. The genes are small with similar structure, are tightly clustered, and have several types of repeats in the second of two exons and that surround each gene. The density of repeats suggests that the genes are positioned within regions of genomic instability, which may be required to drive sequence diversification. The second exon encodes the mature protein and is composed of blocks of sequence called elements that are present in mosaics of defined element patterns and are the major source of sequence diversity. The SpTrf genes respond swiftly to immune challenge, but only a single gene is expressed per phagocyte. Many of the mRNAs appear to be edited and encode proteins with altered and/or missense sequence that are often truncated, of which some may be functional. The standard SpTrf protein structure is an N-terminal glycine-rich region, a central RGD motif, a histidine-rich region, and a C-terminal region. Function is predicted from a recombinant protein, rSpTransformer-E1 (rSpTrf-E1, which binds to Vibrio and Saccharomyces, but not to Bacillus, and binds tightly to lipopolysaccharide, β-1,3-glucan, and flagellin, but not to peptidoglycan. rSpTrf-E1 is intrinsically disordered but transforms to α helical structure in the presence of binding targets including lipopolysaccharide, which may underpin the characteristics of binding to multiple targets. SpTrf proteins associate with coelomocyte membranes, and rSpTrf-E1 binds specifically to phosphatidic acid (PA. When rSpTrf-E1 is bound to PA in liposome membranes, it induces morphological changes in liposomes that correlate with PA clustering and leakage of luminal contents, and it extracts or removes PA from the bilayer

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

    Science.gov (United States)

    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

  20. The Recombinant Sea Urchin Immune Effector Protein, rSpTransformer-E1, Binds to Phosphatidic Acid and Deforms Membranes

    Directory of Open Access Journals (Sweden)

    Cheng Man Lun

    2017-05-01

    Full Text Available The purple sea urchin, Strongylocentrotus purpuratus, possesses a sophisticated innate immune system that functions without adaptive capabilities and responds to pathogens effectively by expressing the highly diverse SpTransformer gene family (formerly the Sp185/333 gene family. The swift gene expression response and the sequence diversity of SpTransformer cDNAs suggest that the encoded proteins have immune functions. Individual sea urchins can express up to 260 distinct SpTransformer proteins, and their diversity suggests that different versions may have different functions. Although the deduced proteins are diverse, they share an overall structure of a hydrophobic leader, a glycine-rich N-terminal region, a histidine-rich region, and a C-terminal region. Circular dichroism analysis of a recombinant SpTransformer protein, rSpTransformer-E1 (rSpTrf-E1 demonstrates that it is intrinsically disordered and transforms to α helical in the presence of buffer additives and binding targets. Although native SpTrf proteins are associated with the membranes of perinuclear vesicles in the phagocyte class of coelomocytes and are present on the surface of small phagocytes, they have no predicted transmembrane region or conserved site for glycophosphatidylinositol linkage. To determine whether native SpTrf proteins associate with phagocyte membranes through interactions with lipids, when rSpTrf-E1 is incubated with lipid-embedded nylon strips, it binds to phosphatidic acid (PA through both the glycine-rich region and the histidine-rich region. Synthetic liposomes composed of PA and phosphatidylcholine show binding between rSpTrf-E1 and PA by fluorescence resonance energy transfer, which is associated with leakage of luminal contents suggesting changes in lipid organization and perhaps liposome lysis. Interactions with liposomes also change membrane curvature leading to liposome budding, fusion, and invagination, which is associated with PA clustering induced

  1. TheSpTransformerGene Family (FormerlySp185/333) in the Purple Sea Urchin and the Functional Diversity of the Anti-Pathogen rSpTransformer-E1 Protein.

    Science.gov (United States)

    Smith, L Courtney; Lun, Cheng Man

    2017-01-01

    The complex innate immune system of sea urchins is underpinned by several multigene families including the SpTransformer family ( SpTrf ; formerly Sp185/333 ) with estimates of ~50 members, although the family size is likely variable among individuals of Strongylocentrotus purpuratus . The genes are small with similar structure, are tightly clustered, and have several types of repeats in the second of two exons and that surround each gene. The density of repeats suggests that the genes are positioned within regions of genomic instability, which may be required to drive sequence diversification. The second exon encodes the mature protein and is composed of blocks of sequence called elements that are present in mosaics of defined element patterns and are the major source of sequence diversity. The SpTrf genes respond swiftly to immune challenge, but only a single gene is expressed per phagocyte. Many of the mRNAs appear to be edited and encode proteins with altered and/or missense sequence that are often truncated, of which some may be functional. The standard SpTrf protein structure is an N-terminal glycine-rich region, a central RGD motif, a histidine-rich region, and a C-terminal region. Function is predicted from a recombinant protein, rSpTransformer-E1 (rSpTrf-E1), which binds to Vibrio and Saccharomyces , but not to Bacillus , and binds tightly to lipopolysaccharide, β-1,3-glucan, and flagellin, but not to peptidoglycan. rSpTrf-E1 is intrinsically disordered but transforms to α helical structure in the presence of binding targets including lipopolysaccharide, which may underpin the characteristics of binding to multiple targets. SpTrf proteins associate with coelomocyte membranes, and rSpTrf-E1 binds specifically to phosphatidic acid (PA). When rSpTrf-E1 is bound to PA in liposome membranes, it induces morphological changes in liposomes that correlate with PA clustering and leakage of luminal contents, and it extracts or removes PA from the bilayer. The

  2. The Recombinant Sea Urchin Immune Effector Protein, rSpTransformer-E1, Binds to Phosphatidic Acid and Deforms Membranes.

    Science.gov (United States)

    Lun, Cheng Man; Samuel, Robin L; Gillmor, Susan D; Boyd, Anthony; Smith, L Courtney

    2017-01-01

    The purple sea urchin, Strongylocentrotus purpuratus , possesses a sophisticated innate immune system that functions without adaptive capabilities and responds to pathogens effectively by expressing the highly diverse SpTransformer gene family (formerly the Sp185/333 gene family). The swift gene expression response and the sequence diversity of SpTransformer cDNAs suggest that the encoded proteins have immune functions. Individual sea urchins can express up to 260 distinct SpTransformer proteins, and their diversity suggests that different versions may have different functions. Although the deduced proteins are diverse, they share an overall structure of a hydrophobic leader, a glycine-rich N-terminal region, a histidine-rich region, and a C-terminal region. Circular dichroism analysis of a recombinant SpTransformer protein, rSpTransformer-E1 (rSpTrf-E1) demonstrates that it is intrinsically disordered and transforms to α helical in the presence of buffer additives and binding targets. Although native SpTrf proteins are associated with the membranes of perinuclear vesicles in the phagocyte class of coelomocytes and are present on the surface of small phagocytes, they have no predicted transmembrane region or conserved site for glycophosphatidylinositol linkage. To determine whether native SpTrf proteins associate with phagocyte membranes through interactions with lipids, when rSpTrf-E1 is incubated with lipid-embedded nylon strips, it binds to phosphatidic acid (PA) through both the glycine-rich region and the histidine-rich region. Synthetic liposomes composed of PA and phosphatidylcholine show binding between rSpTrf-E1 and PA by fluorescence resonance energy transfer, which is associated with leakage of luminal contents suggesting changes in lipid organization and perhaps liposome lysis. Interactions with liposomes also change membrane curvature leading to liposome budding, fusion, and invagination, which is associated with PA clustering induced by rSpTrf-E1

  3. SM50 repeat-polypeptides self-assemble into discrete matrix subunits and promote appositional calcium carbonate crystal growth during sea urchin tooth biomineralization.

    Science.gov (United States)

    Mao, Yelin; Satchell, Paul G; Luan, Xianghong; Diekwisch, Thomas G H

    2016-01-01

    The two major proteins involved in vertebrate enamel formation and echinoderm sea urchin tooth biomineralization, amelogenin and SM50, are both characterized by elongated polyproline repeat domains in the center of the macromolecule. To determine the role of polyproline repeat polypeptides in basal deuterostome biomineralization, we have mapped the localization of SM50 as it relates to crystal growth, conducted self-assembly studies of SM50 repeat polypeptides, and examined their effect on calcium carbonate and apatite crystal growth. Electron micrographs of the growth zone of Strongylocentrotus purpuratus sea urchin teeth documented a series of successive events from intravesicular mineral nucleation to mineral deposition at the interface between tooth surface and odontoblast syncytium. Using immunohistochemistry, SM50 was detected within the cytoplasm of cells associated with the developing tooth mineral, at the mineral secreting front, and adjacent to initial mineral deposits, but not in muscles and ligaments. Polypeptides derived from the SM50 polyproline alternating hexa- and hepta-peptide repeat region (SM50P6P7) formed highly discrete, donut-shaped self-assembly patterns. In calcium carbonate crystal growth studies, SM50P6P7 repeat peptides triggered the growth of expansive networks of fused calcium carbonate crystals while in apatite growth studies, SM50P6P7 peptides facilitated the growth of needle-shaped and parallel arranged crystals resembling those found in developing vertebrate enamel. In comparison, SM50P6P7 surpassed the PXX24 polypeptide repeat region derived from the vertebrate enamel protein amelogenin in its ability to promote crystal nucleation and appositional crystal growth. Together, these studies establish the SM50P6P7 polyproline repeat region as a potent regulator in the protein-guided appositional crystal growth that occurs during continuous tooth mineralization and eruption. In addition, our studies highlight the role of species

  4. The chronic toxicity of molybdate to marine organisms. I. Generating reliable effects data

    Energy Technology Data Exchange (ETDEWEB)

    Heijerick, D.G., E-mail: Dagobert.heijerick@arche-consulting.be [ARCHE - Assessing Risks of Chemicals, Stapelplein 70 Bus 104, Gent (Belgium); Regoli, L. [International Molybdenum Association, 4 Heathfield Terrace, London, W4 4JE (United Kingdom); Stubblefield, W. [Oregon State University, Department of Environmental and Molecular Toxicology, 421 Weniger Hall, Corvallis, OR 97331 (United States)

    2012-07-15

    A scientific research program was initiated by the International Molybdenum Association (IMOA) which addressed identified gaps in the environmental toxicity data for the molybdate ion (MoO{sub 4}{sup 2-}). These gaps were previously identified during the preparation of EU-REACH-dossiers for different molybdenum compounds (European Union regulation on Registration, Evaluation, Authorization and Restriction of Chemical substances; EC, 2006). Evaluation of the open literature identified few reliable marine ecotoxicological data that could be used for deriving a Predicted No-Effect Concentration (PNEC) for the marine environment. Rather than calculating a PNEC{sub marine} using the assessment factor methodology on a combined freshwater/marine dataset, IMOA decided to generate sufficient reliable marine chronic data to permit derivation of a PNEC by means of the more scientifically robust species sensitivity distribution (SSD) approach (also called the statistical extrapolation approach). Nine test species were chronically exposed to molybdate (added as sodium molybdate dihydrate, Na{sub 2}MoO{sub 4}{center_dot}2H{sub 2}O) according to published standard testing guidelines that are acceptable for a broad range of regulatory purposes. The selected test organisms were representative for typical marine trophic levels: micro-algae/diatom (Phaeodactylum tricornutum, Dunaliella tertiolecta), macro-alga (Ceramium tenuicorne), mysids (Americamysis bahia), copepod (Acartia tonsa), fish (Cyprinodon variegatus), echinoderms (Dendraster exentricus, Strongylocentrotus purpuratus) and molluscs (Mytilus edulis, Crassostrea gigas). Available NOEC/EC{sub 10} levels ranged between 4.4 mg Mo/L (blue mussel M. edulis) and 1174 mg Mo/L (oyster C. gigas). Using all available reliable marine chronic effects data that are currently available, a HC{sub 5,50%} (median hazardous concentration affecting 5% of the species) of 5.74 (mg Mo)/L was derived with the statistical extrapolation approach, a

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

    Science.gov (United States)

    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

  6. Juvenile skeletogenesis in anciently diverged sea urchin clades.

    Science.gov (United States)

    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

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

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    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

  8. The SpTransformer Gene Family (Formerly Sp185/333) in the Purple Sea Urchin and the Functional Diversity of the Anti-Pathogen rSpTransformer-E1 Protein

    Science.gov (United States)

    Smith, L. Courtney; Lun, Cheng Man

    2017-01-01

    The complex innate immune system of sea urchins is underpinned by several multigene families including the SpTransformer family (SpTrf; formerly Sp185/333) with estimates of ~50 members, although the family size is likely variable among individuals of Strongylocentrotus purpuratus. The genes are small with similar structure, are tightly clustered, and have several types of repeats in the second of two exons and that surround each gene. The density of repeats suggests that the genes are positioned within regions of genomic instability, which may be required to drive sequence diversification. The second exon encodes the mature protein and is composed of blocks of sequence called elements that are present in mosaics of defined element patterns and are the major source of sequence diversity. The SpTrf genes respond swiftly to immune challenge, but only a single gene is expressed per phagocyte. Many of the mRNAs appear to be edited and encode proteins with altered and/or missense sequence that are often truncated, of which some may be functional. The standard SpTrf protein structure is an N-terminal glycine-rich region, a central RGD motif, a histidine-rich region, and a C-terminal region. Function is predicted from a recombinant protein, rSpTransformer-E1 (rSpTrf-E1), which binds to Vibrio and Saccharomyces, but not to Bacillus, and binds tightly to lipopolysaccharide, β-1,3-glucan, and flagellin, but not to peptidoglycan. rSpTrf-E1 is intrinsically disordered but transforms to α helical structure in the presence of binding targets including lipopolysaccharide, which may underpin the characteristics of binding to multiple targets. SpTrf proteins associate with coelomocyte membranes, and rSpTrf-E1 binds specifically to phosphatidic acid (PA). When rSpTrf-E1 is bound to PA in liposome membranes, it induces morphological changes in liposomes that correlate with PA clustering and leakage of luminal contents, and it extracts or removes PA from the bilayer. The

  9. The 10 sea urchin receptor for egg jelly proteins (SpREJ are members of the polycystic kidney disease-1 (PKD1 family

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    Miyata Shinji

    2007-07-01

    Full Text Available Abstract Background Mutations in the human polycystic kidney disease-1 (hPKD1 gene result in ~85% of cases of autosomal dominant polycystic kidney disease, the most frequent human monogenic disease. PKD1 proteins are large multidomain proteins involved in a variety of signal transduction mechanisms. Obtaining more information about members of the PKD1 family will help to clarify their functions. Humans have five hPKD1 proteins, whereas sea urchins have 10. The PKD1 proteins of the sea urchin, Strongylocentrotus purpuratus, are referred to as the Receptor for Egg Jelly, or SpREJ proteins. The SpREJ proteins form a subfamily within the PKD1 family. They frequently contain C-type lectin domains, PKD repeats, a REJ domain, a GPS domain, a PLAT/LH2 domain, 1–11 transmembrane segments and a C-terminal coiled-coil domain. Results The 10 full-length SpREJ cDNA sequences were determined. The secondary structures of their deduced proteins were predicted and compared to the five human hPKD1 proteins. The genomic structures of the 10 SpREJs show low similarity to each other. All 10 SpREJs are transcribed in either embryos or adult tissues. SpREJs show distinct patterns of expression during embryogenesis. Adult tissues show tissue-specific patterns of SpREJ expression. Conclusion Possession of a REJ domain of about 600 residues defines this family. Except for SpREJ1 and 3, that are thought to be associated with the sperm acrosome reaction, the functions of the other SpREJ proteins remain unknown. The sea urchin genome is one-fourth the size of the human genome, but sea urchins have 10 SpREJ proteins, whereas humans have five. Determination of the tissue specific function of each of these proteins will be of interest to those studying echinoderm development. Sea urchins are basal deuterostomes, the line of evolution leading to the vertebrates. The study of individual PKD1 proteins will increase our knowledge of the importance of this gene family.

  10. Genome-wide signals of positive selection in strongylocentrotid sea urchins.

    Science.gov (United States)

    Kober, Kord M; Pogson, Grant H

    2017-07-21

    Comparative genomics studies investigating the signals of positive selection among groups of closely related species are still rare and limited in taxonomic breadth. Such studies show great promise in advancing our knowledge about the proportion and the identity of genes experiencing diversifying selection. However, methodological challenges have led to high levels of false positives in past studies. Here, we use the well-annotated genome of the purple sea urchin, Strongylocentrotus purpuratus, as a reference to investigate the signals of positive selection at 6520 single-copy orthologs from nine sea urchin species belonging to the family Strongylocentrotidae paying careful attention to minimizing false positives. We identified 1008 (15.5%) candidate positive selection genes (PSGs). Tests for positive selection along the nine terminal branches of the phylogeny identified 824 genes that showed lineage-specific adaptive diversification (1.67% of branch-sites tests performed). Positively selected codons were not enriched at exon borders or near regions containing missing data, suggesting a limited contribution of false positives caused by alignment or annotation errors. Alignments were validated at 10 loci with re-sequencing using Sanger methods. No differences were observed in the rates of synonymous substitution (d S ), GC content, and codon bias between the candidate PSGs and those not showing positive selection. However, the candidate PSGs had 68% higher rates of nonsynonymous substitution (d N ) and 33% lower levels of heterozygosity, consistent with selective sweeps and opposite to that expected by a relaxation of selective constraint. Although positive selection was identified at reproductive proteins and innate immunity genes, the strongest signals of adaptive diversification were observed at extracellular matrix proteins, cell adhesion molecules, membrane receptors, and ion channels. Many candidate PSGs have been widely implicated as targets of pathogen

  11. Procesos naturales y antropogénicos asociados al evento de mortalidad de conchas de abanico ocurrido en la bahía de Paracas (Pisco, Perú en junio del 2000

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    Rita Cabello

    2013-06-01

    Full Text Available Con la finalidad de determinar los procesos que desencadenaron el evento de mortalidad de concha de abanico (Argopecten purpuratus el 6 de junio del 2000, se analizaron las condiciones ambientales naturales y antropogénicas en la Bahía de Paracas (Pisco, Perú durante el período de actividad pesquera industrial pesquera, entre el 17 de mayo y el 13 de junio del 2000. Se evaluaron diariamente las variables oceanográficas de temperatura, oxígeno disuelto, volumen de fitoplancton y variables de calidad acuática, aceites y grasas, sólidos suspendidos totales, DBO5 , pH, sulfuros y coliformes termotolerantes, en 5 estaciones de la Bahía de Paracas. Desde mediados de mayo, se registraron altos contenidos de aceites y grasas provenientes de efluentes pesqueros. A fines de mayo se observó la presencia de una marea roja asociada a un incremento en los sólidos suspendidos totales, pH y oxígeno disuelto, especialmente frente a Atenas y El Chaco. A inicios de junio en superficie se produjo una disminución de los sólidos suspendidos totales (< 25 mg.L-1 y oxígeno (< 3 mL.L-1, llegando a un máximo las concentraciones de grasa (m·x.: 10,1 mg.L-1, mientras que en los fondos el proceso acumulativo de carga orgánica produjo un estado anóxico con alto contenido de sulfuros (m·x.: 19,73 µg-at.L-1. Estas condiciones redujeron la calidad del ambiente marino, y produjeron la mortalidad de los organismos bentónicos. El aporte de materia org·nica proveniente de efluentes pesqueros, junto con el aporte proveniente de la floración algal nociva, ejerció un efecto sinérgico negativo sobre la calidad de la columna de agua y los sedimentos, lo que provocó la mortalidad de especies bentónicas, entre ellas la concha de abanico.

  12. The use of multivariate analysis to link sediment contamination and toxicity data to establish sediment quality guidelines: an example in the Gulf of Cadiz (Spain); El uso del analisis multivariante en la union de datos de toxicidad y contaminacion para establecer guias de calidad de sedimento: Un ejemplo en la Bahia de Cadiz (Espana)

    Energy Technology Data Exchange (ETDEWEB)

    Del Valls, T. Angel; Forja, Jesus M [Departamento de Quimica Fisica, Facultad de Ciencias del Mar, Universidad de Cadiz, Cadiz, (Spain); Gomez-Parra, Abelardo [Instituto de Ciencias Marinas de Andalucia, CSIC, Puerto Real, Cadiz, (Spain)

    1998-03-01

    which biological effects have been shown to be minimal (mg kg{sup -}1 dry sediment), are: Hg, 0.25; Ag, 0.78; Pb, 66.80; Cr, 101.2; LAS, 2.6. [Spanish] Para evaluar la calidad de los sedimentos marinos en el Golfo de Cadiz, los datos provenientes de concentraciones quimicas y respuestas de toxicidad en sedimentos fueron unidos usando el analisis ultivariante. Las muestras de sedimentos fueron recogidas sinopticamente en siete estaciones de dos ecosistemas litorales en el Golfo de Cadiz (cinco en la Bahia de Cadiz y dos en las marismas del rio Barbate) y fueron sujetas a seis tests de toxicidad de forma independiente y replicada, asi como a analisis quimicos. Los efectos toxicos en los sedimentos se chequearon utilizando tres fases operativas del sedimento: sedimento bruto, utilizando el anfipodo Microdeutopus gryllotalpa (10 d estatico: supervivencia) y la almeja de estuario Ruditapes philippinarum (48 h estatico: enterramiento); extracto de sedimento, utilizando larvas del bivalvo de estuario Crassostrea angulata (48 h estatico: supervivencia) y del pez marino Sparus aurata (48 h estatico: supervivencia); y agua intersticial, utilizando poblaciones del rotifero de estuario Brachionus plicatilis (7 d estatico: decaimiento de la poblacion) y de la bacteria marina Photobacterium phosphoreum (Microtox ). Para evaluar los niveles de contaminacion se determinaron las concentraciones en los sedimentos de carbono organico, 14 metales traza (Fe, Mn, Cu, Zn, Pb, Cd, Ag, Hg, As, Sn, V, Ni, Co y Cr) y el detergente alquibencenosulfonato lineal (LAS). Los resultados de los ensayos de toxicidad se compararon mediante relaciones de respuesta entre las diferentes estaciones, demostrando una concordancia general entre los valores de toxicidad determinados en todos los tests, excepto en el caso de la toxicidad en el agua intersticial (principalmente debido a mezclas de metales traza toxicas). Los datos obtenidos en los ensayos quimicos y de toxicidad se ensamblaron utilizando tecnicas

  13. Molluscan assemblage from a tropical intertidal estuarine sand-mud flat, Gulf of Nicoya, Pacific, Costa Rica (1984-1987

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    José A Vargas-Zamora

    2011-09-01

    computación y programas de cómputo facilitan el re-análisis de antiguos datos y la identificación de patrones ocultos en ellos. desde febrero de 1984 hasta abril de 1987 (49 fechas de colecta, muestras de barreno (17.7cm², 15cm de profundidad fueron recolectadas durante la marea baja en una planicie arenosa-fangosa en la región media del estuario del Golfo de Nicoya, Costa Rica. Experimentos de exclusión de depredadores (jaulas 0.5x0.5x0.2m, malla galvanizada, poro de 5mm, fueron realizados en el sitio en 1985 (estación seca vs estación lluviosa. Las muestras fueron preservadas con formalina al 5% en agua de mar teñida con Rosa de Bengala y lavadas después de 24 horas en un tamiz de 500 micras de poro de malla. Los 1 120 barrenos produjeron un total de 112 especie morfológicas, de las cuales los moluscos estuvieron representados por 23 especies que incluyen los bivalvos: Tellina rubescens, Tagelus bourgeoisae, Dosinia dunkeri y Leukoma asperrima, y los gastrópodos, Natica unifasciata, Nassarius luteostomus, Costoanachis rugosa y Turbonilla sp. Las 23 especies son indicadoras de una fauna de moluscos relativamente rica. T. bourgeoisae presentó una oscilación estacional, con mayor abundancia durante la estación de lluvias. T. rubescens no fue estacional, pero presentó una oscilación con máximos a intervalos de cerca de 1.5 años. Muchas conchas vacías de Cosmioconcha modesta, un poco menos de N. luteostomus y unas pocas de T. rubescens fueron encontradas con perforaciones hechas por el depredador N. unifasciata. T. rubescens no fue significativamente más abundande dentro o fuera de las jaulas. T. bourgeoisae mostró una falta de abundancia estacional, pero una densidad significativamente mayor dentro de las jaulas. Las fluctuaciones poblacionales de los moluscos fueron más importantes durante la estación de lluvias cuando se les compara con las fluctuaciones de los poliquetos, crustáceos y otros grupos. Mareas rojas en el Golfo de Nicoya durante 1985

  14. Seasonal and interannual variability in population abundances of the intertidal macroinfauna of Queule river estuary, south-central Chile Variabilidad estacional e interanual en las abundancias poblacionales de la macroinfauna intermareal del estuario del río Queule, centro-sur de Chile

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    EDUARDO JARAMILLO

    2001-06-01

    P. gualpensis. No significant differences among years were found for the total macroinfauna, P. (M. patagonica, P. gualpensis and P. hartmannorum at the muddy-sand site. On the other hand, the abundances of Capitella sp. and K. chilenica differed significantly among years. Significant differences among months within annual periods were found for the total macroinfauna and species population abundances at the sandy and muddy-sand sites. The temporal variability of the macroinfauna did not have any significant relationship with the temporal variability in sediment characteristicsDurante octubre de 1990 a abril de 1992 y entre septiembre de 1995 a noviembre de 1997 se recolectaron muestras mensuales de sedimento en el estuario del río Queule (ca. 39° S, centro sur de Chile, con el objetivo de estudiar la variabilidad temporal en las abundancias poblacionales de la macroinfauna que habita los sustratos arenosos y areno-fangosos del intermareal. Los sedimentos arenosos tuvieron mayores porcentajes de partículas de arena y porcentajes más bajos de partículas de fango, agregados biogénicos y materia orgánica total en relación a los sedimentos areno-fangosos. Se encontraron las mismas especies de macroinfauna en ambos sitios. La macroinfauna total estuvo dominada por poliquetos: Prionospio (Minuspio patagonica Augener 1923, Capitella sp. y Perinereis gualpensis Jeldes 1963. Otros organismos comunes fueron el anfípodo Paracorophium hartamannorum Andres 1975 y el pequeño bivalvo Kingiella chilenica Soot-Ryen 1959. Las abundancias más altas de la macroinfauna total ocurrieron usualmente durante los meses de verano (enero-febrero. La especie más abundante fue P. (M. patagonica (hasta 130-140.000 ind m-2 en los sedimentos areno-fangosos. Durante algunos meses, esta especie tuvo abundancias significativamente más altas en esos sedimentos. Tendencia similar es la mostrada por P. hartmannorum; i.e., abundancias significativamente más altas en los sedimentos areno

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  16. Molecular evolution of Phox-related regulatory subunits for NADPH oxidase enzymes

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    Lambeth J David

    2007-09-01

    Full Text Available Abstract Background The reactive oxygen-generating NADPH oxidases (Noxes function in a variety of biological roles, and can be broadly classified into those that are regulated by subunit interactions and those that are regulated by calcium. The prototypical subunit-regulated Nox, Nox2, is the membrane-associated catalytic subunit of the phagocyte NADPH-oxidase. Nox2 forms a heterodimer with the integral membrane protein, p22phox, and this heterodimer binds to the regulatory subunits p47phox, p67phox, p40phox and the small GTPase Rac, triggering superoxide generation. Nox-organizer protein 1 (NOXO1 and Nox-activator 1 (NOXA1, respective homologs of p47phox and p67phox, together with p22phox and Rac, activate Nox1, a non-phagocytic homolog of Nox2. NOXO1 and p22phox also regulate Nox3, whereas Nox4 requires only p22phox. In this study, we have assembled and analyzed amino acid sequences of Nox regulatory subunit orthologs from vertebrates, a urochordate, an echinoderm, a mollusc, a cnidarian, a choanoflagellate, fungi and a slime mold amoeba to investigate the evolutionary history of these subunits. Results Ancestral p47phox, p67phox, and p22phox genes are broadly seen in the metazoa, except for the ecdysozoans. The choanoflagellate Monosiga brevicollis, the unicellular organism that is the closest relatives of multicellular animals, encodes early prototypes of p22phox, p47phox as well as the earliest known Nox2-like ancestor of the Nox1-3 subfamily. p67phox- and p47phox-like genes are seen in the sea urchin Strongylocentrotus purpuratus and the limpet Lottia gigantea that also possess Nox2-like co-orthologs of vertebrate Nox1-3. Duplication of primordial p47phox and p67phox genes occurred in vertebrates, with the duplicated branches evolving into NOXO1 and NOXA1. Analysis of characteristic domains of regulatory subunits suggests a novel view of the evolution of Nox: in fish, p40phox participated in regulating both Nox1 and Nox2, but after the

  17. El fenómeno 'El Niño' y los moluscos de la Costa peruana

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    1993-01-01

    ópico, como en depósitos geológicos naturales. Por la distribución de las provincias zoogeográficas en la costa del Perú y por el fuerte impacto de las anomalías océano-climáticas del Niño en esta región, es de esperarse que las conchas de moluscos subactuales o fósiles puedan jugar un papel importante en la identificación de ocurrencias de eventos El Niño en el pasado. Se analizan, pues, las evidencias de presencia/ausencia de ciertas especies de bivalvos y gasterópodos en depósitos arqueológicos y geológicos, a la luz de las observaciones realizadas sobre el impacto de los eventos recientes de 1982-1983 y 1986-1987. Esta recopilación de datos relativos a eventos El Niño de los últimos años y a posibles ocurrencias del fenómeno en épocas más remotas, muestra que todavía quedan muchas incógnitas en cuanto a la dinámica poblacional y la ecología de los moluscos en respuesta a la anomalía oceanográfica. Por lo tanto, una cierta prudencia es necesaria al pretender reconstituir este tipo de anomalías en el pasado. En algunos casos, sin embargo, se presume la ocurrencia de condiciones de tipo El Niño, durante el Holoceno como en ciertos interglaciales del Pleistoceno, las que aparentemente permitieron el traslado de larvas de organismos de la Provincia Panameña, o de la Zona de Transición de Paita, hasta las costas del Centro y Sur del Perú (Provincia Peruana. EL NIÑO PHENOMENON AND THE MOLLUSCS OF THE PERUVIAN COAST. Among other El Niño biomarkers, coastal molluscs present the advantage of having a calcareous test that can easily be preserved in prehistoric shell mounds as well as in natural geological deposits. The distribution of the zoogeographic provinces along the Peruvian coast, and the strong impact of the El Niño oceano-climatic anomaly on this coastal region lead to consider that fossil mollusc shells may play a major role in the identification of former El Niño events. Therefore, we examined a series of reports on the presence