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Sample records for argopecten purpuratus lamarck

  1. In vitro fertilization with cryopreserved spermatozoa in small pieces of gonad of the scallop Argopecten purpuratus (Lamarck, 1819).

    PubMed

    Dupré, Enrique; Covarrubias, Alejandra; Goldstein, Merari; Guerrero, Alicia; Rojas, Herman

    2016-10-01

    The aim of this work was to evaluate the fertilization rates through the first cleavage, obtained with fresh oocytes inseminated with sperm cryopreserved at different freezing rates (-8.8,-10 and -12 °C/min) and at two thawing rates, using cryoprotectant solution (Me2SO, at 1 M, 2 M, 3 M, 4 M and 5 M with or without egg yolk and sucrose). Sperm contained in small pieces of male gonad were frozen at the three freezing rates, stored in liquid nitrogen and later the samples were thawed at two rates by immersing the samples in water at 50 °C (rapid) or 30 °C. Control fertilization rates ranged from 69.2 ± 2.8%-45.5% ± 1.6%. To determine the best concentration of the cryoprotectant (between 1 M and 5 M), in a first step, a freezing of -15 °C/min and a rapid thawing was used. Fertilization rates ranged between 9.6 ± 2.5% and 34.6± 12.2% and the highest percentages of fertilized oocytes (34.6%) was obtained with 3 M concentration with cryoaditive. The second step, using 3 M Me2SO with cryoadditive, determined that the freezing rate -8.8 °C/min produces the best result 29 ± 2.9% of fertilized oocytes corresponding to 59.2 ± 9.1% compared to controls. Although there were no significant differences among the different freezing rates, the fertilization rate tended to be higher with a lower freezing rate. Comparing the results of the present study, which used a cryoprotective solution composed of Me2SO and a cryoadditive, to those of other studies that used Me2SO without cryoadditives, suggests that the addition of a cryoadditive to the cryoprotectant Me2SO improves the fertilizing capacity of the sperm of Argopecten purpuratus after being cryopreserved.

  2. Pathogenicity of a highly exopolysaccharide-producing Halomonas strain causing epizootics in larval cultures of the Chilean scallop Argopecten purpuratus (Lamarck, 1819).

    PubMed

    Rojas, Rodrigo; Miranda, Claudio D; Amaro, Ana María

    2009-01-01

    Mass mortalities of larval cultures of Chilean scallop Argopecten purpuratus have repeatedly occurred in northern Chile, characterized by larval agglutination and accumulation in the bottom of rearing tanks. The exopolysaccharide slime (EPS) producing CAM2 strain was isolated as the primary organism from moribund larvae in a pathogenic outbreak occurring in a commercial hatchery producing larvae of the Chilean scallop Argopecten purpuratus located in Bahía Inglesa, Chile. The CAM2 strain was characterized biochemically and was identified by polymerase chain reaction amplification of 16S rRNA as Halomonas sp. (Accession number DQ885389.1). Healthy 7-day-old scallop larvae cultures were experimentally infected for a 48-h period with an overnight culture of the CAM2 strain at a final concentration of ca. 10(5) cells per milliliter, and the mortality and vital condition of larvae were determined by optical and scanning electron microscopy (SEM) to describe the chronology of the disease. Pathogenic action of the CAM2 strain was clearly evidenced by SEM analysis, showing a high ability to adhere and detach larvae velum cells by using its "slimy" EPS, producing agglutination, loss of motility, and a posterior sinking of scallop larvae. After 48 h, a dense bacterial slime on the shell surface was observed, producing high percentages of larval agglutination (63.28 +/- 7.87%) and mortality (45.03 +/- 4.32%) that were significantly (P < 0.05) higher than those of the unchallenged control cultures, which exhibited only 3.20 +/- 1.40% dead larvae and no larval agglutination. Furthermore, the CAM2 strain exhibited a high ability to adhere to fiberglass pieces of tanks used for scallop larvae rearing (1.64 x 10(5) cells adhered per square millimeters at 24 h postinoculation), making it very difficult to eradicate it from the culture systems. This is the first report of a pathogenic activity on scallop larvae of Halomonas species, and it prompts the necessity of an appraisal on

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Mitochondrial genome of the Peruvian scallop Argopecten purpuratus (Bivalvia: Pectinidae).

    PubMed

    Marín, Alan; Alfaro, Rubén; Fujimoto, Takafumi; Arai, Katsutoshi

    2015-01-01

    The mitochondrial genome of the Peruvian scallop Argopecten purpuratus was determined. The length of the mitochondrial coding region is 15,608 bp. A typical bivalve mitochondrial composition was detected with 12 protein-coding genes, 2 ribosomal RNA genes and 21 transfer RNA genes, with the absence of the atp8 gene. Fifty percent of the protein-coding genes use typical ATG start codon, whereas five genes utilize ATA as their start codon. Only one gene was found to utilize TTG as its start codon. The A. purpuratus mitogenome shows a significant similarity to that of A. irradians irradians, in length as well as in gene composition.

  5. Molecular genetic analysis of heterosis in interspecific hybrids of Argopecten purpuratus x A. irradians irradians.

    PubMed

    Hu, L P; Huang, X T; Sun, Y; Mao, J X; Wang, S; Wang, C D; Bao, Z M

    2015-09-09

    Argopecten purpuratus and Argopecten irradians irradians hybridization was successfully performed and the hybrid offspring displayed apparent heterosis in growth traits. To better understand the genetic basis of heterosis, the genomic composition and genetic variation of the hybrids were analyzed with amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Seven of eight universal SSR primers displayed polymorphism in the hybrids and their parental groups, and hybrids inherited both parental geno-types at each locus. Using five primer combinations in AFLP analysis, 433 loci were amplified in the hybrids and their parental groups. The frequency of polymorphisms was 88.22%. F1 hybrids inherited 88.11 and 92.88% of AFLP bands from their parents. Some loci did not follow Mendelian Law, including 48 loci in parents that were lost, and 11 new loci that were amplified in the hybrids. The parameters of Nei's gene diversity, Shannon's Information index, genetic distance, and molecular variance between groups were calculated. The genetic differentiation between two hybrid groups (0.253) was smaller than that between hybrids and their parents (0.554 to 0.645), and was especially smaller than that between two parental groups (0.769). The high genetic similarity (0.9347) and low genetic differentiation (0.2531) between two hybrid groups suggests that these hybrid groups were genetically very close. Heterozygosities of hybrid groups were higher than those of parental groups, indicating that the hybrids had increased genetic diversity.

  6. Genome Sequence of Vibrio VPAP30, Isolated from an Episode of Massive Mortality of Reared Larvae of the Scallop Argopecten purpuratus

    PubMed Central

    Rojas, Rodrigo; Miranda, Claudio D.; Romero, Jaime; Asenjo, Freddy; Valderrama, Katherinne; Segovia, Cristopher

    2015-01-01

    We report here the 5.167-Mbp draft genome sequence of Vibrio VPAP30, isolated from an Argopecten purpuratus larval culture. Vibrio VPAP30 is the etiological agent of a vibriosis outbreak causing a complete collapse of a larval culture of the scallop A. purpuratus, which occurred in a commercial hatchery in Chile. PMID:26159530

  7. Genomic Characterization of Interspecific Hybrids between the Scallops Argopecten purpuratus and A. irradians irradians

    PubMed Central

    Hu, Liping; Huang, Xiaoting; Mao, Junxia; Wang, Chunde; Bao, Zhenmin

    2013-01-01

    The Peruvian scallop (Argopecten purpuratus) has been introduced to China and has successfully been hybridized with the bay scallop (A. irradians irradians). The F1 hybrids of these two scallops exhibited a large increase in production traits and some other interesting new characteristics. To understand the genetic basis of this heterosis, nuclear gene and partial mtDNA sequences, and genomic in situ hybridization (GISH) were employed to analyze the genomic organization of the hybrids. Amplification of the ribosomal DNA internal transcribed spacer (ITS) showed that the parental ITS sequences were present in all the hybrid individuals, illustrating that the hybrid offspring inherited nuclear DNA from both parents. Sequence analyses of the ITS region further confirmed that the hybrids harbored alleles from their parents; some recombinant variants were also detected, which revealed some alterations in the nuclear genetic material of the hybrids. The analysis of mitochondrial 16S rDNA showed that the hybrids possessed sequences that were identical to the 16S rDNA of the female parents, proving a matrilineal inheritance of mitochondrial genes in scallops. In addition, GISH clearly discriminated between the parental chromosomes and indicated a combination of haploid genomes of duplex parents in the hybrids. The genetic analyses in our study illustrated that the F1 hybrids inherited nuclear material from both parents and cytoplasmic genetic material maternally, and some variations occurred in the genome, which might contribute to a further understanding of crossbreeding and heterosis in scallop species. PMID:23620828

  8. Inheritance of the general shell color in the scallop Argopecten purpuratus (Bivalvia: Pectinidae).

    PubMed

    Winkler, F M; Estévez, B F; Jollán, L B; Garrido, J P

    2001-01-01

    Although some external coloration and pigmentation patterns in molluscan shells may be attributable to environmental factors, most variation in these phenotypic characters depends on uncomplicated genetic mechanisms. Genetic research on inheritance of color variations in the north-Chilean scallop (Argopecten purpuratus) has now been expanded to analyze color segregation in juvenile scallops produced under controlled conditions employing self- and cross-fertilization. Calculations from the results were used for comparison with different numerical models based on Mendelian inheritance, and results were also obtained on the inheritance of a dorsoventral white line often observed on the left (upper) valve in this species. The results confirmed the hereditary basis for color variation in the shell of this scallop, suggesting a simple, dominant model of epistasis to explain the distribution of the different color variants observed (purple, brown, orange, yellow, and white). The presence of the white line may be controlled by a recessive allele with simple Mendelian traits on a locus distinct from those that control color variation.

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

    PubMed

    Ramajo, Laura; Marbà, Núria; Prado, Luis; Peron, Sophie; Lardies, Marco A; Rodriguez-Navarro, Alejandro B; Vargas, Cristian A; Lagos, Nelson A; Duarte, Carlos M

    2016-06-01

    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.

  10. Transcriptomic response of Argopecten purpuratus post-larvae to copper exposure under experimental conditions.

    PubMed

    Zapata, Manuel; Tanguy, Arnaud; David, Elise; Moraga, Dario; Riquelme, Carlos

    2009-08-01

    Few studies have described the molecular response of mollusk larvae to heavy metal exposure. We investigated the response of Chilean scallop Argopecten purpuratus post-larvae to copper exposure under experimental conditions. Post-larvae were maintained with and without copper stress in tanks containing netlon collectors with biofilms that were formed by the bacterium Halomonas sp. and the diatom Amphora sp., known to increase larval settlement. We focused on the analysis of the differential expression patterns of genes associated with copper response. A suppression subtractive hybridization method was used to identify copper-specific up- and down-regulated genes in the post-larvae following 4 days and 8 days exposure to 2.5 and 10 microg/l Cu(+2). This method revealed 145 different sequences corresponding to 10 major physiological functions. The expression of 15 potentially regulated genes was analyzed by real-time PCR in post-larvae at different sampling times during the copper stress. The genes chosen were alpha tubulin, elongation factor 1-alpha (EF1A), tributylin binding protein type 1 (TBT), NADH dehydrogenase subunit 2 (NADH2), cavortin, glutathione peroxidase (GPx), ferritin, heat shock protein 70 (HSP70), Pam highwire rpm1 (Phr1), insulin-like growth factor 1 (IGF1), cellulase, and ribosomal proteins: L18, L44, S3a and S15. This study contributes to the characterization of potential genetic markers that could be used in future environmental monitoring and to explore new mechanisms of stress tolerance in marine mollusk species, especially in early stages of development.

  11. Energy vs. essential fatty acids: what do scallop larvae (Argopecten purpuratus) need most?

    PubMed

    Nevejan, Nancy; Saez, Iris; Gajardo, Gonzalo; Sorgeloos, Patrick

    2003-04-01

    Larvae of the Chilean-Peruvian scallop Argopecten purpuratus were fed a Dunaliella tertiolecta diet (Dun-diet) supplemented with lipid emulsions, rich in 20:5n-3 (EmEPA), 22:6n-3 (EmDHA) or in saturated fatty acids (EmCOCO). A mixed algal diet of Isochrysis galbana (T-iso) and Chaetoceros neogracile served as a positive control (St-diet). Lipid supplementation to the Dun-diet improved the larval growth and increased the percentage of eyed larvae significantly, compared to the non-supplemented Dun-diet because of the extra energy supplied and not because of its fatty acid composition. No significant differences were observed between supplementation with EmEPA, EmDHA or EmCOCO. A mixture of 20% EmEPA+20% EmDHA (40% EmHUFA) was more efficient in raising the total lipid content in larvae than 40% EmCOCO. Both emulsions increased the triacylglycerol content in larvae compared to the non-supplemented Dun-diet. The best result, however, was obtained with the St-diet, probably because of a more suitable 18:2n-6/18:3n-3 ratio and a higher level of arachidonic acid. A positive relationship between the 18:2n-6/18:3n-3 ratio and the larval performance was found. No significant difference was observed in post-settlement larval size or percentage of metamorphosed larvae between the St-diet and the St-diet supplemented with 20% EmHUFA or 20% EmCOCO. The metamorphosed larvae had a constant DHA/EPA ratio of 3.7, independent from the diet, which suggested a metabolic control of the two fatty acids and a species-dependency of the ratio.

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

    NASA Astrophysics Data System (ADS)

    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

  13. A novel antifungal peptide designed from the primary structure of a natural antimicrobial peptide purified from Argopecten purpuratus hemocytes.

    PubMed

    Arenas, Gloria; Guzmán, Fanny; Cárdenas, Constanza; Mercado, Luis; Marshall, Sergio H

    2009-08-01

    We have isolated and purified a natural antimicrobial peptide from Argopecten purpuratus hemocytes. 47 residues were determined from its primary structure representing the N-terminal of the complete sequence. This peptide of 5100.78Da was chemically synthesized and named Ap. The peptide has 25% of hydrophobic amino acids with a net charge of +1, and partial homology with known active antimicrobial peptides. Based on that sequence, a new peptide was designed and modeled to increase hydrophobicity and cationicity. The designed 30-residue peptide was chemically synthesized resulting in a novel 38% hydrophobic molecule named peptide Ap-S, with a net charge of +5 and 3028Da. A secondary structure was shown by circular dichroism, thus exposing a hydrophobic epitope toward the N-terminus and a hydrophilic one toward the C-terminus, improving amphipathicity. Ap-S was much more active than the parental Ap. Ap-S up to 100microM has no cytotoxic effect against fish cell line CHSE-214. We demonstrated that the chemical modification of a natural peptide and the chemical synthesis of derived molecules may be a powerful tool for obtaining substitutes to conventional antibiotics, displaying the many advantages of antimicrobial peptides and overcoming the limitations of natural peptides for large-scale production and application, such as the low specific activity and the minute amounts recovered in vivo. This peptide may have a relevant application in aquaculture by controlling Saprolegna sp., a parasitic pathogen fungus that attacks the culture of fish in different stages of their growth, from egg to adult.

  14. Molecular characterization of two ferritins of the scallop Argopecten purpuratus and gene expressions in association with early development, immune response and growth rate.

    PubMed

    Coba de la Peña, Teodoro; Cárcamo, Claudia B; Díaz, María I; Brokordt, Katherina B; Winkler, Federico M

    2016-08-01

    Ferritin is involved in several iron homoeostasis processes in molluscs. We characterized two ferritin homologues and their expression patterns in association with early development, growth rate and immune response in the scallop Argopecten purpuratus, a species of economic importance for Chile and Peru. Two ferritin subunits (Apfer1 and Apfer2) were cloned. Apfer1 cDNA is a 792bp clone containing a 516bp open reading frame (ORF) that corresponds to a novel ferritin subunit in A. purpuratus. Apfer2 cDNA is a 681bp clone containing a 522bp ORF that corresponds to a previously sequenced EST. A putative iron responsive element (IRE) was identified in the 5'-untranslated region of both genes. The deduced protein sequences of both cDNAs possessed the motifs and domains characteristic of functional ferritin subunits. Both genes showed differential expression patterns at tissue-specific and early development stage levels. Apfer1 expression level increased 40-fold along larval developmental stages, decreasing markedly after larval settlement. Apfer1 expression in mantle tissue was 2.8-fold higher in fast-growing than in slow-growing scallops. Apfer1 increased 8-fold in haemocytes 24h post-challenge with the bacterium Vibrio splendidus. Apfer2 expression did not differ between fast- and slow-growing scallops or in response to bacterial challenge. These results suggest that Apfer1 and Apfer2 may be involved in iron storage, larval development and shell formation. Apfer1 expression may additionally be involved in immune response against bacterial infections and also in growth; and thus would be a potential marker for immune capacity and for fast growth in A. purpuratus.

  15. First Report of Vibrio tubiashii Associated with a Massive Larval Mortality Event in a Commercial Hatchery of Scallop Argopecten purpuratus in Chile

    PubMed Central

    Rojas, Rodrigo; Miranda, Claudio D.; Santander, Javier; Romero, Jaime

    2016-01-01

    The VPAP30 strain was isolated as the highly predominant bacteria from an episode of massive larval mortality occurring in a commercial culture of the Chilean scallop Argopecten purpuratus. The main aims of this study were, to characterize and identify the pathogenic strain using biochemical and molecular methods to demonstrate its pathogenic activity on scallop larvae, to characterize its pathogenic properties and to describe the chronology of this pathology. The pathogenic strain was identified as Vibrio tubiashii based on its phenotypic properties and the sequence analysis of its 16S rRNA and housekeeping genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA). When triplicate cultures of healthy 10–day–old scallop larvae were challenged with 1 × 105 colony forming units (CFU) mL-1 of the VPAP30 strain, percentages of larval survival of 78.87 ± 3.33%, 34.32 ± 4.94%, and 0% were observed at 12, 24, and 36 h, respectively; whereas uninfected larval cultures showed survival rates of 97.4 ± 1.24% after of 48 h. Clinical symptoms exhibited by the scallop larvae infected with the VPAP30 strain include the accumulation of bacteria around the scallop larvae, velum disruption and necrosis of digestive gland. The 50% lethal dose (LD50) of VPAP30 strain at 24 and 48 h was 1.3 × 104 and 1.2 × 103 CFU mL-1, respectively. The invasive pathogenic activity of the VPAP30 strain was investigated with staining of the bacterial pathogen with 5-DTAF and analyzing bacterial invasion using epifluorescence, and a complete bacterial dissemination inside the larvae at 24 h post-infection was observed. When scallop larvae were inoculated with cell-free extracellular products (ECPs) of VPAP30, the larval survival rate was 59.5 ± 1.66%, significantly (P < 0.001) lower than the control group (97.4 ± 1.20%) whereas larvae treated with heat-treated ECPs exhibited a survival rate of 61.6 ± 1.84% after 48 h of exposure. This is the first report of the isolation of V. tubiashii

  16. First Report of Vibrio tubiashii Associated with a Massive Larval Mortality Event in a Commercial Hatchery of Scallop Argopecten purpuratus in Chile.

    PubMed

    Rojas, Rodrigo; Miranda, Claudio D; Santander, Javier; Romero, Jaime

    2016-01-01

    The VPAP30 strain was isolated as the highly predominant bacteria from an episode of massive larval mortality occurring in a commercial culture of the Chilean scallop Argopecten purpuratus. The main aims of this study were, to characterize and identify the pathogenic strain using biochemical and molecular methods to demonstrate its pathogenic activity on scallop larvae, to characterize its pathogenic properties and to describe the chronology of this pathology. The pathogenic strain was identified as Vibrio tubiashii based on its phenotypic properties and the sequence analysis of its 16S rRNA and housekeeping genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA). When triplicate cultures of healthy 10-day-old scallop larvae were challenged with 1 × 10(5) colony forming units (CFU) mL(-1) of the VPAP30 strain, percentages of larval survival of 78.87 ± 3.33%, 34.32 ± 4.94%, and 0% were observed at 12, 24, and 36 h, respectively; whereas uninfected larval cultures showed survival rates of 97.4 ± 1.24% after of 48 h. Clinical symptoms exhibited by the scallop larvae infected with the VPAP30 strain include the accumulation of bacteria around the scallop larvae, velum disruption and necrosis of digestive gland. The 50% lethal dose (LD50) of VPAP30 strain at 24 and 48 h was 1.3 × 10(4) and 1.2 × 10(3) CFU mL(-1), respectively. The invasive pathogenic activity of the VPAP30 strain was investigated with staining of the bacterial pathogen with 5-DTAF and analyzing bacterial invasion using epifluorescence, and a complete bacterial dissemination inside the larvae at 24 h post-infection was observed. When scallop larvae were inoculated with cell-free extracellular products (ECPs) of VPAP30, the larval survival rate was 59.5 ± 1.66%, significantly (P < 0.001) lower than the control group (97.4 ± 1.20%) whereas larvae treated with heat-treated ECPs exhibited a survival rate of 61.6 ± 1.84% after 48 h of exposure. This is the first report of the isolation of V

  17. Expression of an optimized Argopecten purpuratus antimicrobial peptide in E. coli and evaluation of the purified recombinant protein by in vitro challenges against important plant fungi.

    PubMed

    Tapia, Eduardo; Montes, Christian; Rebufel, Patricia; Paradela, Alberto; Prieto, Humberto; Arenas, Gloria

    2011-09-01

    Antimicrobial peptides (AMP) have been widely described in several organisms from different kingdoms. We recently designed and evaluated a synthetic version of an AMP isolated and characterized from Argopecten purpuratus hemocytes. This study describes the generation of a chimaeric gene encoding for Ap-S, the use of this construct to transform E. coli strain BL21, and the evaluation of the purified recombinant Ap-S (rApS) as an antifungal agent. The proposed gene coding for rAp-S consists of 93 nucleotides arranged downstream from the IPTG-inducible T7 promoter. The best synthesis conditions were obtained after E. coli cultivation at 26°C for 3h, which allowed for the production of an rAp-S-enriched fraction containing the peptide at 249μM. Mass spectrometry analysis of the purified rAp-S (3085.80Da) showed the addition of a glycine residue on its N-terminal end derived from vector design and peptide purification. The purified rApS fraction was assayed for antifungal activity by direct addition of purified rApS elution to potato dextrose agar media at a final concentration of 81nM. These assays showed important growth inhibitions of both biotrophic (Fusarium oxysporum, Trichoderma harzianum) and necrotrophic (Botrytis cinerea, Alternaria spp.) fungi in that the hyphae structures and spore count were affected in all cases. The strategy of cloning and expressing rAp-S in E. coli, the high yield obtained and its successful use for controlling pathogenic fungi suggest that this molecule could be applied to agricultural crops using various management strategies.

  18. Effects of elevated seawater pCO2 on early development of scallop Argopecten irradias (Lamarck, 1819)

    NASA Astrophysics Data System (ADS)

    Wang, Weimin; Liu, Guangxing; Zhang, Tianwen; Chen, Hongju; Tang, Liao; Mao, Xuewei

    2016-12-01

    To investigate the effects of elevated seawater pCO2 on the early developmental stages of marine benthic calcifying organisms, we exposed the eggs and larvae of Argopecten irradias, an important bivalve species in Chinese aquaculture, in seawater equilibrated with CO2-enriched (1000 ppm) gas mixtures. We demonstrated that elevated seawater pCO2 significantly interfered with fertilization and larval development and resulted in an increased aberration rate. Fertilization in the treatment (pH 7.6) was 74.3% ± 3.8%, which was 9.7% lower than that in the control (pH 8.3) (84.0% ±3.0%). Hatching success decreased by 23.7%, and aberration rate increased by 30.3% under acidic condition. Larvae in acidified seawater still developed a shell during the post-embryonic phase. However, the shell length and height in the treatment were smaller than those in the control. The development of embryos differed significantly at 12 h after fertilization between the two experimental groups. Embryos developed slower in acidified seawater. Nearly half of the embryos in the control developed into D-shaped larvae at 48 h after fertilization, which were considerably more than those in the treatment (11.7%). Results suggest that future ocean acidification (OA) would cause detrimental effects on the early development of A. irradias.

  19. Molecular characterization of an inhibitor of NF-κB in the scallop Argopecten purpuratus: First insights into its role on antimicrobial peptide regulation in a mollusk.

    PubMed

    Oyanedel, D; Gonzalez, R; Flores-Herrera, P; Brokordt, K; Rosa, R D; Mercado, L; Schmitt, P

    2016-05-01

    Inhibitors of nuclear factor kappa B (IκBs) are major control components of the Rel/NF-κB signaling pathway, a key regulator in the modulation of the expression of immune-related genes in vertebrates and invertebrates. The activation of the Rel/NF-κB signaling pathway depends largely in the degradation of IκB proteins and thus, IκBs are a main target for the identification of genes whose expression is controlled by Rel/NF-κB pathway. In order to identify such regulation in bivalve mollusks, the cDNA sequence encoding an IκB protein was characterized in the scallop Argopecten purpuratus, ApIκB. The cDNA sequence of ApIκB is comprised of 1480 nucleotides with a 1086 bp open reading frame encoding for 362 amino acids. Bioinformatics analysis showed that ApIκB displays the conserved features of IκB proteins. The deduced amino acid sequence consists of a 39.7 kDa protein, which has an N-terminal degradation motif, six ankyrin repeats and a C-terminal phosphorylation site motif. Phylogenetic analysis revealed a high degree of identity between ApIκB and other IκBs from mollusks, but also to arthropod cactus proteins and vertebrate IκBs. Tissue expression analysis indicated that ApIκB is expressed in all examined tissues and it is upregulated in circulating hemocytes from scallops challenged with the pathogenic Gram-negative bacterium Vibrio splendidus. After inhibiting ApIκB gene expression using the RNA interference technology, the gene expression of the antimicrobial peptide big defensin was upregulated in hemocytes from non-challenged scallops. Results suggest that ApIκB may control the expression of antimicrobial effectors such as big defensin via a putative Rel/NF-κB signaling pathway. This first evidence will help to deepen the knowledge of the Rel/NF-κB conserved pathway in scallops.

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

    PubMed

    Avendaño, Miguel; Cantillánez, Marcela; Le Pennec, Marcel; Thouzeau, Gérard

    2008-03-01

    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).

  1. Epigenetics, Darwin, and Lamarck

    PubMed Central

    Penny, David

    2015-01-01

    It is not really helpful to consider modern environmental epigenetics as neo-Lamarckian; and there is no evidence that Lamarck considered the idea original to himself. We must all keep learning about inheritance, but attributing modern ideas to early researchers is not helpful, and can be misleading. PMID:26026157

  2. Genomic in situ hybridization identifies parental chromosomes in hybrid scallop (Bivalvia, Pectinoida, Pectinidae) between female Chlamys farreri and male Argopecten irradians irradians

    PubMed Central

    Huang, Xiaoting; Bi, Ke; Lu, Wei; Wang, Shi; Zhang, Lingling; Bao, Zhenmin

    2015-01-01

    Abstract Interspecific crossing was artificially carried out between Chlamys farreri (Jones & Preston, 1904) ♀ and Argopecten irradians irradians (Lamarck, 1819) ♂, two of the dominant cultivated scallop species in China. Genomic in situ hybridization (GISH) was used to examine the chromosome constitution and variation in hybrids at early embryonic stage. The number of chromosomes in 66.38% of the metaphases was 2n = 35 and the karyotype was 2n = 3 m + 5 sm + 16 st + 11 t. After GISH, two parental genomes were clearly distinguished in hybrids, most of which comprised 19 chromosomes derived from their female parent (Chlamys farreri) and 16 chromosomes from their male parent (Argopecten irradians irradians). Some chromosome elimination and fragmentation was also observed in the hybrids. PMID:26140161

  3. JUVENILE BAY SCALLOP (ARGOPECTEN IRRADIANS) HABITAT PREFERENCES

    EPA Science Inventory

    Habitat quality and quantity are known to be important for maintaining populations of bay scallops (Argopecten irradians), but data linking habitat attributes to bay scallop populations are lacking. This information is essential to understand the role of habitat alteration in th...

  4. A HABITAT SUITABILITY INDEX FOR THE BAY SCALLOP ARGOPECTEN IRRADIANS

    EPA Science Inventory

    Poster presentation at a scientific meeting. A survey of Lagoon Pond, Martha's Vineyard, MA, USA was conducted in September 2005 to determine the combination of habitat factors most highly correlated with the bay scallop Argopecten irradians) abundance. A stratified random samp...

  5. The Impact of Lamarck's Theory of Evolution Before Darwin's Theory.

    PubMed

    Galera, Andrés

    2017-02-01

    This paper analyzes the impact that Lamarckian evolutionary theory had in the scientific community during the period between the advent of Zoological Philosophy and the publication Origin of Species. During these 50 years Lamarck's model was a well known theory and it was discussed by the scientific community as a hypothesis to explain the changing nature of the fossil record throughout the history of Earth. Lamarck's transmutation theory established the foundation of an evolutionary model introducing a new way to research in nature. Darwin's selectionist theory was proposed in 1859 to explain the origin of species within this epistemological process. In this context, Charles Lyell's Principles of Geology and Auguste Comte's Cours de Philosophie Positive appear as two major works for the dissemination of Lamarck's evolutionary ideology after the death of the French naturalist in 1829.

  6. Age and intrusive relations of the Lamarck granodiorite and associated mafic plutons, Sierra Nevada, California

    SciTech Connect

    Joye, J.L.; Bachl, C.A.; Miller, J.S.; Glazner, A.F. . Dept. of Geology); Frost, T.P. ); Coleman, D.S. . Dept. of Earth, Atmospheric and Planetary Sciences)

    1993-04-01

    The compositionally zoned Late Cretaceous Lamarck granodiorite, west of Bishop, hosts numerous mafic intrusions ranging from hornblende gabbro to mafic granodiorite. Frost and Mahood (1987) suggested from field relations that the Lamarck and the associated mafic plutons were co-intrusive. Contact relations between the Lamarck host and the mafic intrusions are variable (sharp to diffuse) and in places suggest commingling. In order to constrain the intrusive relationships between the Lamarck and its associated mafic plutons, the authors have analyzed feldspars from the Mt. Gilbert pluton and the Lamarck granodiorite to see if feldspar compositions in the Mt. Gilbert overlap those in the Lamarck host and determined U-Pb zircon ages for the Mt. Gilbert and Lake Sabrina plutons to see if they have the same age as the Lamarck granodiorite. Feldspars from the Lamarck granodiorite are normally zoned and range compositionally from An[sub 38--32]; those in the Mt. Gilbert diorite are also normally zoned but range compositionally from An[sub 49--41] and do not overlap the Lamarck host. Four to five zircon fractions from each pluton were handpicked and dated using U-Pb methods. The Mt. Gilbert mafic diorite has a concordant age of 92.5 Ma and the Lake Sabrina diorite has a concordant age of 91.5 Ma. Ages for the two plutons overlap within error, but multiple fractions from each suggest that the Lake Sabrina pluton is slightly younger than the Mt. Gilbert pluton. These data and field relationships indicate: (1) plagioclase phenocrysts in the Mt. Gilbert pluton were not derived from the Lamarck granodiorite despite their textural similarity; but (2) the Lamarck granodiorite and its associated mafic plutons are co-intrusive as supported by the close agreement of the ages with the crystallization age obtained by Stern and others for the Lamarck granodiorite.

  7. Freud's 'Lamarckism' and the politics of racial science.

    PubMed

    Slavet, Eliza

    2008-01-01

    This article re-contextualizes Sigmund Freud's interest in the idea of the inheritance of acquired characteristics in terms of the socio-political connotations of Lamarckism and Darwinism in the 1930s and 1950s. Many scholars have speculated as to why Freud continued to insist on a supposedly outmoded theory of evolution in the 1930s even as he was aware that it was no longer tenable. While Freud's initial interest in the inheritance of phylogenetic memory was not necessarily politically motivated, his refusal to abandon this theory in the 1930s must be understood in terms of wider debates, especially regarding the position of the Jewish people in Germany and Austria. Freud became uneasy about the inheritance of memory not because it was scientifically disproven, but because it had become politically charged and suspiciously regarded by the Nazis as Bolshevik and Jewish. Where Freud seemed to use the idea of inherited memory as a way of universalizing his theory beyond the individual cultural milieu of his mostly Jewish patients, such a notion of universal science itself became politically charged and identified as particularly Jewish. The vexed and speculative interpretations of Freud's Lamarckism are situated as part of a larger post-War cultural reaction against Communism on the one hand (particularly in the 1950s when Lamarckism was associated with the failures of Lysenko), and on the other hand, against any scientific concepts of race in the wake of World War II.

  8. The genome of the sea urchin Strongylocentrotus purpuratus.

    PubMed

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

    2006-11-10

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

  9. French roots of French neo-lamarckisms, 1879-1985.

    PubMed

    Loison, Laurent

    2011-01-01

    This essay attempts to describe the neo-Lamarckian atmosphere that was dominant in French biology for more than a century. Firstly, we demonstrate that there were not one but at least two French neo-Lamarckian traditions. This implies, therefore, that it is possible to propose a clear definition of a (neo)Lamarckian conception, and by using it, to distinguish these two traditions. We will see that these two conceptions were not dominant at the same time. The first French neo-Lamarckism (1879-1931) was structured by a very mechanic view of natural processes. The main representatives of this first period were scientists such as Alfred Giard (1846-1908), Gaston Bonnier (1853-1922) and Félix Le Dantec (1869-1917). The second Lamarckism - much more vitalist in its inspiration - started to develop under the supervision of people such as Albert Vandel (1894-1980) and Pierre-Paul Grassé (1895-1985). Secondly, this essay suggests that the philosophical inclinations of these neo-Lamarckisms reactivated a very ancient and strong dichotomy of French thought. One part of this dichotomy is a material, physicalist tradition, which started with René Descartes but developed extensively during the 18th and 19th centuries. The other is a spiritual and vitalist reaction to the first one, which also had a very long history, though it is most closely associated with the work of Henri Bergson. Through Claude Bernard, the first neo-Lamarckians tried to construct a mechanical and determinist form of evolutionary theory which was, in effect, a Cartesian theory. The second wave of neo-Lamarckians wanted to reconsider the autonomy and reactivity of life forms, in contrast to purely physical systems.

  10. The identity of Callicarpa minutiflora Y. Y. Qian (Lamiaceae) and taxonomic synonym of C. longifolia Lamarck

    PubMed Central

    Ma, Zhonghui; Su, Zhiwei

    2016-01-01

    Abstract Although the specific epithet of Callicarpa minutiflora Y. Y. Qian has been revised for many times, during the study of the genus Callicarpa, we find that Callicarpa minutiflora Y. Y. Qian is identical to Callicarpa longifolia Lamarck by a series of morphologic characters. In order to avoid more confusion, here Callicarpa minutiflora Y. Y. Qian is reduced as a synonym of Callicarpa longifolia Lamarck. PMID:28127241

  11. Lamarck, Evolution, and the Inheritance of Acquired Characters

    PubMed Central

    Burkhardt, Richard W.

    2013-01-01

    Scientists are not always remembered for the ideas they cherished most. In the case of the French biologist Jean-Baptiste Lamarck, his name since the end of the nineteenth century has been tightly linked to the idea of the inheritance of acquired characters. This was indeed an idea that he endorsed, but he did not claim it as his own nor did he give it much thought. He took pride instead in advancing the ideas that (1) nature produced successively all the different forms of life on earth, and (2) environmentally induced behavioral changes lead the way in species change. This article surveys Lamarck’s ideas about organic change, identifies several ironies with respect to how his name is commonly remembered, and suggests that some historical justice might be done by using the adjective “Lamarckian” to denote something more (or other) than a belief in the inheritance of acquired characters. PMID:23908372

  12. The larval stages of the sea urchin, Strongylocentrotus purpuratus.

    PubMed

    Smith, M Meighan; Cruz Smith, Luisa; Cameron, R Andrew; Urry, Lisa A

    2008-06-01

    The adult body plan of Strongylocentrotus purpuratus is established within the imaginal rudiment during the larval stages. To facilitate the study of these stages, we have defined a larval staging scheme, which consists of seven stages: Stage I, four-arm stage; Stage II, eight-arm stage; Stage III, vestibular invagination stage; Stage IV, rudiment initiation stage; Stage V, pentagonal disc stage; Stage VI, advanced rudiment stage; and Stage VI, tube-foot protrusion stage. Each stage is characterized by significant morphological features observed for the first time at that stage. This scheme is intended as a guide for determining the degree of larval development, and for identifying larval and adult structures. Larval anatomy was visualized using light and confocal microscopy as required on living material, whole mount fixed specimens, and serial sections. Antibody staining to localize specific gene products was also used. Detailed analysis of these data has furthered our understanding of the morphogenesis of the rudiment, and has suggested provocative questions regarding the molecular basis for these events. We intend this work to be of use to investigators studying gene expression and morphogenesis in postembryonic larvae.

  13. Apoptosis in early development of the sea urchin, Strongylocentrotus purpuratus.

    PubMed

    Vega Thurber, Rebecca; Epel, David

    2007-03-01

    Apoptosis provides metazoans remarkable developmental flexibility by (1) eliminating damaged undifferentiated cells early in development and then (2) sculpting, patterning, and restructuring tissues during successive stages thereafter. We show here that apoptotic programmed cell death is infrequent and not obligatory during early embryogenesis of the purple sea urchin, Strongylocentrotus purpuratus. During the first 30 h of urchin development, fewer than 20% of embryos exhibit any cell death. Cell death during the cleavage stages consists of necrotic or pathological cell death, while cell death during the blastula and gastrula stages is random and predominantly caspase-mediated apoptosis. Apoptosis remains infrequent during the late blastula stage followed by a gradual increase in frequency during gastrulation. Even after prolonged exposure during the cleavage period to chemical stress, apoptosis occurs in less than 50% of embryos and always around the pre-hatching stage. Embryonic suppression of apoptosis through caspase inhibition leads to functionally normal larvae that can survive to metamorphosis, but in the presence of inducers of apoptosis, caspase inhibition leads to deformed larvae and reduced survival. Remarkably, however, pharmacological induction of apoptosis, while reducing overall survival, also significantly accelerates development of the survivors such that metamorphosis occurs up to a week before controls.

  14. Refertilization in eggs of the sea urchin Strongylocentrotus purpuratus.

    PubMed

    Kubota, L F; Carroll, E J

    1988-09-01

    To determine the role of the sea urchin egg plasma membrane in the species-specificity of fertilization, the ability of denuded activated eggs to be heterospecifically refertilized was determined. Our initial studies included evaluating the effectiveness of three commonly used methods of vitelline envelope (VE) removal using indirect immunofluorescence microscopy with antibodies directed against the VE. Unfertilized Strongylocentrotus purpuratus eggs were extracted with 0.01 M dithiothreitol (DTT) for 3 min or digested with 1.0 mg/ml pronase for 1 hr. Eggs were also fertilized, then diluted into a divalent-free medium to produce thin, elevated envelopes (VE*s) that were mechanically removed by sieving the eggs through nylon mesh. We found that both DTT extraction and pronase digestion were not completely effective in VE removal, and mechanical removal methods gave rise to a mixed population of eggs, those that had their VEs removed and those with a collapsed envelope that was not detectable at the light microscope level. Therefore, a new method of VE removal was developed. Eggs with VE*s were prepared followed by treatment with 0.01 M DTT to solubilize the envelopes. Nearly 100% of the denuded activated eggs incorporated one or more homologous and heterologous sperm, suggesting that the egg plasma membrane does not function in determining the species-specificity of fertilization.

  15. Structure and mechanical properties of Saxidomus purpuratus biological shells.

    PubMed

    Yang, W; Zhang, G P; Zhu, X F; Li, X W; Meyers, M A

    2011-10-01

    The strength and fracture behavior of Saxidomus purpuratus shells were investigated and correlated with the structure. The shells show a crossed lamellar structure in the inner and middle layers and a fibrous/blocky and porous structure composed of nanoscaled particulates (~100 nm diameter) in the outer layer. It was found that the flexure strength and fracture mode are a function of lamellar organization and orientation. The crossed lamellar structure of this shell is composed of domains of parallel lamellae with approximate thickness of 200-600 nm. These domains have approximate lateral dimensions of 10-70 μm with a minimum of two orientations of lamellae in the inner and middle layers. Neighboring domains are oriented at specific angles and thus the structure forms a crossed lamellar pattern. The microhardness across the thickness was lower in the outer layer because of the porosity and the absence of lamellae. The tensile (from flexure tests) and compressive strengths were analyzed by means of Weibull statistics. The mean tensile (flexure) strength at probability of 50%, 80-105 MPa, is on the same order as the compressive strength (~50-150 MPa) and the Weibull moduli vary from 3.0 to 7.6. These values are significantly lower than abalone nacre, in spite of having the same aragonite structure. The lower strength can be attributed to a smaller fraction of the organic interlayer. The fracture path in the specimens is dominated by the orientation of the domains and proceeds preferentially along lamella boundaries. It also correlates with the color changes in the cross section of the shell. The cracks tend to undergo a considerable change in orientation when the color changes abruptly. The distributions of strengths, cracking paths, and fracture surfaces indicate that the mechanical properties of the shell are anisotropic with a hierarchical nature.

  16. Sphedgehog is expressed by pigment cell precursors during early gastrulation in Strongylocentrotus purpuratus.

    PubMed

    Egaña, Ana L; Ernst, Susan G

    2004-10-01

    We have sequenced the Sphedgehog (Sphh) gene from the sea urchin Strongylocentrotus purpuratus. Sphh transcripts are detected first at the mesenchyme blastula stage, and they accumulate throughout early embryogenesis. The Sphh protein is produced by precursor pigment cells during early and midgastrulation. NiCl2 inhibits pigment cell differentiation in sea urchins. Here, we show that, in S. purpuratus, nickel affects a process(es) between 17 and 24 hr of development, corresponding to the time period when Sphh mRNA is first detected. However, nickel treatment does not alter the early expression of Sphh.

  17. Strongylocentrotus purpuratus spindle tubulin. II. Characteristics of its sensitivity to Ca++ and the effects of calmodulin isolated from bovine brain and S. purpuratus eggs

    PubMed Central

    1982-01-01

    Tubulin was extracted from spindles isolated from embryos of the sea urchin Strongylocentrotus purpuratus and purified through cycles of temperature-dependent assembly and disassembly. At 37 degrees C, the majority of the cycle-purified spindle tubulin polymer is insensitive to free Ca++ at concentrations below 0.4 mM, requiring free Ca++ concentrations greater than 1 mM for complete depolymerization. However, free Ca++ at concentrations above 1 microM inhibits initiation of polymer formation without significantly inhibiting the rate of elongation onto existing polymer. At 15 degrees C and 18 degrees C, temperatures that are physiological for S. purpuratus embryos, spindle tubulin polymer is sensitive to free Ca++ at micromolar concentrations such that 3-20 microM free Ca++ causes complete depolymerization. Calmodulin purified from either bovine brain or S. purpuratus eggs does not affect the Ca++ sensitivity of the spindle tubulin at 37 degrees C, although both increase the Ca++ sensitivity of cycle-purified bovine brain tubulin. These results indicate that cycle-purified spindle tubulin and cycle-purified bovine brain tubulin differ significantly in their responses to calmodulin and in their Ca++ sensitivities at their physiological temperatures. They also suggest that, in vivo, spindle tubulin may be regulated by physiological levels of intracellular Ca++ in the absence of Ca++-sensitizing factors. PMID:7119003

  18. Analytical psychology and the ghost of Lamarck: did Jung believe in the inheritance of acquired characteristics?

    PubMed

    Rensma, Ritske

    2013-04-01

    Whether Jung was a Lamarckian or not has always been a hotly debated topic, both within the post-Jungian community and amongst scholars with an interest in Jung in the wider academic community. Yet surprisingly few substantial pieces of work have been dedicated to it and, to my mind, no one has yet managed to do justice to all the subtleties involved. The scholars who have claimed that Jung is a Lamarckian have, for the most part, oversimplified the debate by failing to discuss the passages in which Jung appears to be defending himself against Lamarckism; the scholars who have defended Jung against Lamarckism, however, have as a rule not adequately dealt with the question of whether these passages actually get Jung off the hook. This paper will attempt to correct this imbalance by putting forward four key passages spanning Jung's career that all represent conclusive evidence that Jung was indeed a Lamarckian. After discussing these, it will then deal in detail with the passages in which Jung appears to be defending himself against Lamarckism, making the case that they do not represent a defence against Lamarckism at all and have therefore generally been misinterpreted by many scholars.

  19. Cytological comparison of gametogenesis of scallops, Argopecten irradians and Chlamys farreri

    NASA Astrophysics Data System (ADS)

    Dong, Xin-Hong; Liu, Bao-Zhong; Wu, Chang-Gong; Xiang, Jian-Hai

    2002-09-01

    Histological characteristics of gametogenesis of two kinds of scallops, gonochoric Chinese scallop, Chlamys farreri and hermaphroditic bay scallop, Argopecten irradians were investigated in this study. Spermatogenesis in C. farreri has different developmental stages: spermatogonia, primary spermatocyte, second spermatocyte, spermatid and spermatozoon. A large number of same developmental stage spermatic cells converge at a definite area of the testis. Premeiotic, previtellogenic and vitellogenic oocytes can be found during oogenesis in C. farreri, where oocyte distribution is obviously irregular. The A. irradians gonad consists of two different parts in one individual: one part functions as testis, the other as ovary. Between these two parts is a special appearance area, where a large number of spermatic cells are bound with two layers of acellular substance with many oocytes in it.

  20. Presence of two mitochondrial genomes in the mytilid Perumytilus purpuratus: Phylogenetic evidence for doubly uniparental inheritance

    PubMed Central

    Vargas, Jaime; Pérez, Montse; Toro, Jorge; Astorga, Marcela P.

    2015-01-01

    This study presents evidence, using sequences of ribosomal 16S and COI mtDNA, for the presence of two mitochondrial genomes in Perumytilus purpuratus. This may be considered evidence of doubly uniparental mtDNA inheritance. The presence of the two types of mitochondrial genomes differentiates females from males. The F genome was found in the somatic and gonadal tissues of females and in the somatic tissues of males; the M genome was found in the gonads and mantle of males only. For the mitochondrial 16S region, ten haplotypes were found for the F genome (nucleotide diversity 0.004), and 7 haplotypes for the M genome (nucleotide diversity 0.001), with a distance Dxy of 0.125 and divergence Kxy of 60.33%. For the COI gene 17 haplotypes were found for the F genome (nucleotide diversity 0.009), and 10 haplotypes for the M genome (nucleotide diversity 0.010), with a genetic distance Dxy of 0.184 and divergence Kxy of 99.97%. Our results report the presence of two well-differentiated, sex-specific types of mitochondrial genome (one present in the male gonad, the other in the female gonad), implying the presence of DUI in P. purpuratus. These results indicate that care must be taken in phylogenetic comparisons using mtDNA sequences of P. purpuratus without considering the sex of the individuals. PMID:26273220

  1. Review of Australasian spider flies (Diptera, Acroceridae) with a revision of Panops Lamarck

    PubMed Central

    Winterton, Shaun L.

    2012-01-01

    Abstract The Australasian spider flies (Diptera: Acroceridae) are reviewed, with all eight currently recognized genera diagnosed and figured. The panopine genus Panops Lamarck, 1804 from Australia and Indonesia is revised with four new species described, increasing the total number of species in the genus to nine: Panops aurum sp. n., Panops danielsi sp. n., Panops jade sp. n. and Panops schlingeri sp. n. Five species of Panops are redescribed: Panops austrae Neboiss, 1971, Panops baudini Lamarck, 1804, Panops boharti (Schlinger, 1959), comb. n., Panops conspicuus (Brunetti, 1926) and Panops grossi (Neboiss, 1971), comb. n. The monotypic genera Neopanops Schlinger, 1959 and Panocalda Neboiss, 1971 are synonymized with Panops. Keys to genera of Australasian Acroceridae and species of Panops, Helle Osten Sacken, 1896 and Australasian Pterodontia Gray, 1832 are included. PMID:22448114

  2. Marine Toxin Okadaic Acid Affects the Immune Function of Bay Scallop (Argopecten irradians).

    PubMed

    Chi, Cheng; Giri, Sib Sankar; Jun, Jin Woo; Kim, Hyoun Joong; Yun, Saekil; Kim, Sang Guen; Park, Se Chang

    2016-08-24

    Okadaic acid (OA) is produced by dinoflagellates during harmful algal blooms and is a diarrhetic shellfish poisoning toxin. This toxin is particularly problematic for bivalves that are cultured for human consumption. This study aimed to reveal the effects of exposure to OA on the immune responses of bay scallop, Argopecten irradians. Various immunological parameters were assessed (total hemocyte counts (THC), reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), lactate dehydrogenase (LDH), and nitric oxide (NO) in the hemolymph of scallops at 3, 6, 12, 24, and 48 h post-exposure (hpe) to different concentrations of OA (50, 100, and 500 nM). Moreover, the expression of immune-system-related genes (CLT-6, FREP, HSP90, MT, and Cu/ZnSOD) was also measured. Results showed that ROS, MDA, and NO levels and LDH activity were enhanced after exposure to different concentrations of OA; however, both THC and GSH decreased between 24-48 hpe. The expression of immune-system-related genes was also assessed at different time points during the exposure period. Overall, our results suggest that exposure to OA had negative effects on immune system function, increased oxygenic stress, and disrupted metabolism of bay scallops.

  3. A STAGE-BASED POPULATION MODEL FOR BAY SCALLOPS (ARGOPECTEN IRRADIANS) AND IMPLICATIONS FOR POPULATION-LEVEL EFFECTS OF HABITAT ATLERATION.

    EPA Science Inventory

    Bay scallops (Argopecten irradians) inhabit shallow subtidal habitats along the Atlantic coast of the United States and require settlement substrates, such as submerged aquatic vegetation (SAV), for their early juvenile stages. The short lifespan of bay scallops (1-2 yr) coupled...

  4. Purple sea urchin Strongylocentrotus purpuratus gamete manipulation using optical trapping and microfluidics

    NASA Astrophysics Data System (ADS)

    Chandsawangbhuwana, Charlie; Shi, Linda Z.; Zhu, Qingyuan; Berns, Michael W.

    2013-04-01

    A system has been developed that allows for optical and fluidic manipulation of gametes. The optical manipulation is performed by using a single-point gradient trap with a 40× oil immersion PH3 1.3 NA objective on a Zeiss inverted microscope. The fluidic manipulation is performed by using a custom microfluidic chamber designed to fit into the short working distance between the condenser and objective. The system is validated using purple sea urchin Strongylocentrotus purpuratus gametes and has the potential to be used for mammalian in vitro fertilization and animal husbandry.

  5. The involvement of HSP22 from bay scallop Argopecten irradians in response to heavy metal stress.

    PubMed

    Zhang, Lei; Wang, Lingling; Song, Linsheng; Zhao, Jianmin; Qiu, Limei; Dong, Chaohua; Li, Fengmei; Zhang, Huan; Yang, Guanpin

    2010-04-01

    Heat shock protein 22 (HSP22) is an important member of small heat shock protein (sHSP) subfamily which plays a key role in the process of protecting cells, facilitating the folding of nascent peptides, and responding to stress. In the present study, the cDNA of HSP22 was cloned from Argopecten irradians (designated as AiHSP22) by rapid amplification cDNA end (RACE) based on the expressed sequence tags (ESTs). The full-length cDNA of AiHSP22 was of 1,112 bp, with an open reading frame of 588 bp encoding a polypeptide of 195 amino acids. The deduced amino acid sequence of AiHSP22 showed high similarity to previously identified HSP22s. The expression patterns of AiHSP22 mRNA in different tissues and in haemocytes of scallops exposed to Cd(2+), Pb(2+) or Cu(2+) were investigated by real-time quantitative RT-PCR. The mRNA of AiHSP22 was constitutively expressed in all examined tissues, including haemocyte, muscle, kidney, gonad, gill and heart. The expression level in heart and muscle was higher than that in other tissues. The mRNA level of AiHSP22 in haemocytes was up-regulated after a 10 days exposure of scallops to Cu(2+), Pb(2+) and Cd(2+). However, the expression of AiHSP22 did not increase linearly along with the rise of heavy metal concentration. Different concentrations of the same metal resulted in different effects on AiHSP22 expression. The sensitive response of AiHSP22 to Cu(2+), Pb(2+) and Cd(2+) stress indicated that it could be developed as an indicator of exposure to heavy metals for the pollution monitoring programs in aquatic environment.

  6. Morphological and molecular analyses of larval trematodes in the intertidal bivalve Perumytilus purpuratus from central Chile.

    PubMed

    Muñoz, G; López, Z; Cárdenas, L

    2013-09-01

    The bivalve Perumytilus purpuratus is a common species that is widely distributed throughout rocky intertidal zones in Chile. This bivalve is the first intermediate host for three trematode species: one bucephalid (an undetermined species) and two fellodistomids (Proctoeces lintoni and one undetermined species). A few studies based on morphological comparisons, experimental infection and molecular analyses have been performed to ascertain the taxon (at least at the family level) to which these trematodes belong; yet, there remains no clarification about the specific identity of these trematodes. Therefore, in this study, we compared the V4 region nucleotide sequences of the 18S rRNA of these three sporocyst species, classified as morphotypes, found in P. purpuratus and nine adult trematode species from intertidal fishes that are likely definitive hosts for these parasites. The sequences from two of the sporocyst morphotypes matched with adult trematodes from the intertidal fish: type 1 sporocyst was similar to Prosorhynchoides carvajali (Bucephalidae), with a mean genetic divergence of 0.78%, and type 2 sporocyst was similar to Proctoeces sp. (but not P. lintoni), with 0% genetic divergence. The third species (type 3 sporocyst) was classified to the family Fellodistomidae; however, the sequence from this species differed greatly from the three other fellodistomid species documented in the marine fish of Chile and from other fellodistomids in public databases. Moreover, this morphotype has a particular cercarial morphology that greatly differs from other fellodistomid species described thus far. Therefore, this intriguing trematode remains a mystery.

  7. Gene structure in the sea urchin Strongylocentrotus purpuratus based on transcriptome analysis.

    PubMed

    Tu, Qiang; Cameron, R Andrew; Worley, Kim C; Gibbs, Richard A; Davidson, Eric H

    2012-10-01

    A comprehensive transcriptome analysis has been performed on protein-coding RNAs of Strongylocentrotus purpuratus, including 10 different embryonic stages, six feeding larval and metamorphosed juvenile stages, and six adult tissues. In this study, we pooled the transcriptomes from all of these sources and focused on the insights they provide for gene structure in the genome of this recently sequenced model system. The genome had initially been annotated by use of computational gene model prediction algorithms. A large fraction of these predicted genes were recovered in the transcriptome when the reads were mapped to the genome and appropriately filtered and analyzed. However, in a manually curated subset, we discovered that more than half the computational gene model predictions were imperfect, containing errors such as missing exons, prediction of nonexistent exons, erroneous intron/exon boundaries, fusion of adjacent genes, and prediction of multiple genes from single genes. The transcriptome data have been used to provide a systematic upgrade of the gene model predictions throughout the genome, very greatly improving the research usability of the genomic sequence. We have constructed new public databases that incorporate information from the transcriptome analyses. The transcript-based gene model data were used to define average structural parameters for S. purpuratus protein-coding genes. In addition, we constructed a custom sea urchin gene ontology, and assigned about 7000 different annotated transcripts to 24 functional classes. Strong correlations became evident between given functional ontology classes and structural properties, including gene size, exon number, and exon and intron size.

  8. Evidence from the lamarck granodiorite for rapid late cretaceous crust formation in California

    USGS Publications Warehouse

    Coleman, D.S.; Frost, T.P.; Glazner, A.F.

    1992-01-01

    Strontium and neodymium isotopic data for rocks from the voluminous 90-million-year-old Lamarck intrusive suite in the Sierra Nevada batholith, California, show little variation across a compositional range from gabbro to granite. Data for three different gabbro intrusions within the suite are identical within analytical error and are consistent with derivation from an enriched mantle source. Recognition of local involvement of enriched mantle during generation of the Sierran batholith modifies estimates of crustal growth rates in the United States. These data indicate that parts of the Sierra Nevada batholith may consist almost entirely of juvenile crust added during Cretaceous magmatism.

  9. Evidence from the lamarck granodiorite for rapid late cretaceous crust formation in california.

    PubMed

    Coleman, D S; Glazner, A F; Frost, T P

    1992-12-18

    Strontium and neodymium isotopic data for rocks from the voluminous 90-million-year-old Lamarck intrusive suite in the Sierra Nevada batholith, California, show little variation across a compositional range from gabbro to granite. Data for three different gabbro intrusions within the suite are identical within analytical error and are consistent with derivation from an enriched mantle source. Recognition of local involvement of enriched mantle during generation of the Sierran batholith modifies estimates of crustal growth rates in the United States. These data indicate that parts of the Sierra Nevada batholith may consist almost entirely of juvenile crust added during Cretaceous magmatism.

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

    PubMed Central

    2012-01-01

    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 conclude that HA is a modulator

  11. Contractile properties of the striated adductor muscle in the bay scallop Argopecten irradians at several temperatures.

    PubMed

    Olson, J M; Marsh, R L

    1993-03-01

    The isometric and isotonic contractile properties of the cross-striated adductor muscle of the bay scallop (Argopecten irradians) were measured in vitro at 10, 15 and 20 degrees C. The length at which twitch force was maximal as a function of the closed length in situ (L0/Lcl) averaged 1.38 +/- 0.01 (mean +/- S.E.M.) at 10 degrees C. This length is very close to the typical length at maximum gape during natural swimming at this temperature. Passive force was very low over the range of lengths measured here; at L0, passive force averaged approximately 0.08 N cm-2, or only 0.5% of the corresponding peak twitch force. The mean peak isometric twitch force (Ptw,max) at 10 degrees C was 21.43 +/- 0.68 N cm-2 (S.E.M.), and the ratio of peak twitch force to tetanic force (Ptw,max/P0) averaged 0.89 +/- 0.01. Temperature did not affect either twitch force (Ptw), once fatigue was taken into account, or Ptw,max/P0. In contrast, the time-related properties of twitch contractions (latent period, tL; time to peak tension, tPtw; and time from peak tension to half-relaxation, t50%R) were positively modified by temperature at all temperatures measured (Q10 > 1.8). All three properties were more temperature-sensitive over the range 10-15 degrees C than over the range 15-20 degrees C. The force-velocity relationships of the striated adductor muscle were fitted to the hyperbolic-linear (HYP-LIN) equation. The force-velocity curves of the striated adductor muscle of the scallop were strongly influenced by temperature. Maximal velocity at zero force (Vmax), and therefore maximal power output, increased significantly with temperature. The Q10 over the temperature range 10-15 degrees C (1.42) was significantly lower than that over the range 15-20 degrees C (2.41). The shape of the force-velocity relationship, assessed through comparisons of the power ratio (Wmax/VmaxP0), was not influenced by temperature.

  12. The Vindication of Lamarck? Epigenetics at the Intersection of Law and Mental Health.

    PubMed

    DeLisi, Matt; Vaughn, Michael G

    2015-10-01

    Research on epigenetic mechanisms is gaining traction, yet is poorly understood by criminologists and behavioral scientists. The current objective is to review relevant studies of interest to behavioral scientists who study crime, and to translate admittedly challenging scientific information into text that is digestible to the average criminologist. Using systematic search procedures the authors identified and reviewed 41 studies of epigenetic mechanisms in psychiatric and behavioral phenotypes among humans. Findings revealed significant epigenetic effects in an assortment of genes that are implicated in the etiology of depression, suicidality, callous-unemotional traits, and chronic and intergenerational aggressive behavior. Several polymorphisms that mediate the HPA axis, neurotransmission, immune response, brain development, serotonin synthesis, and other processes were found. Although prescriptive knowledge based on epigenetic findings to date is premature, epigenetics is a new and exciting scientific frontier not too different in spirit from Lamarck's observations centuries ago.

  13. [Lamarck needs Darwin: the search for purpose in the study of evolution and of history].

    PubMed

    Moreno, Juan

    2009-01-01

    Lamarck's theory of the inheritance of acquired characteristics and immediate responses to environmental challenges has offered a promise of protagonism of human beings and their fellow travellers, the other organisms, in the evolutionary process. Darwin's theory about evolution by natural selection does not offer this consolation and does not presuppose anything else other than gradual changes in the composition of natural populations. The study of ecology, ethology, neurobiology, animal culture, psychology and human history reveals that the lamarckian interpretations of change and character transmission processes always assume what they intend to explain, that is previous processes of darwinian evolution that guarantee the adaptive nature of the observed responses. The permanent search of direction and intentionality in evolutionary processes by many scientists suggests the limited acceptance of materialistic explanations as those offered by Darwin's theory.

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

    PubMed

    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.

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

    SciTech Connect

    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.

  16. Spatial and temporal variation in results of purple urchin (Strongylocentrotus purpuratus) toxicity tests with zinc

    SciTech Connect

    Phillips, B.M.; Anderson, B.S.; Hunt, J.W.

    1998-03-01

    Purple urchins (Strongylocentrotus purpuratus) were maintained in year-round spawning condition in the laboratory for use in fertilization and larval development experiments designed to assess temporal variability in response to zinc. Results of these tests were compared to those from tests using gametes obtained from a field-collected population. Fertilization and larval development tests were also conducted comparing field-collected purple urchins from three geographically distinct groups on the West Coast of the United States. Fertilization tests conducted to assess temporal variability produced variable median effects concentrations (EC50s) ranging from 4.1 to >100 {micro}g/L zinc. Larval development tests did not demonstrate significant differences in response to zinc between geographically distinct purple urchin populations. Fertilization test variability was examined in terms of sperm concentration and sperm collection method during two seasons. Reduced variability was found with dry sperm collection in tests conducted in March 1995 but increased again in tests conducted in June 1995, regardless of sperm collection method. Increased variability in response to zinc may be caused by seasonal temperature effects.

  17. Characterization of the proteins comprising the integral matrix of Strongylocentrotus purpuratus embryonic spicules

    NASA Technical Reports Server (NTRS)

    Killian, C. E.; Wilt, F. H.

    1996-01-01

    In the present study, we enumerate and characterize the proteins that comprise the integral spicule matrix of the Strongylocentrotus purpuratus embryo. Two-dimensional gel electrophoresis of [35S]methionine radiolabeled spicule matrix proteins reveals that there are 12 strongly radiolabeled spicule matrix proteins and approximately three dozen less strongly radiolabeled spicule matrix proteins. The majority of the proteins have acidic isoelectric points; however, there are several spicule matrix proteins that have more alkaline isoelectric points. Western blotting analysis indicates that SM50 is the spicule matrix protein with the most alkaline isoelectric point. In addition, two distinct SM30 proteins are identified in embryonic spicules, and they have apparent molecular masses of approximately 43 and 46 kDa. Comparisons between embryonic spicule matrix proteins and adult spine integral matrix proteins suggest that the embryonic 43-kDa SM30 protein is an embryonic isoform of SM30. An adult 49-kDa spine matrix protein is also identified as a possible adult isoform of SM30. Analysis of the SM30 amino acid sequences indicates that a portion of SM30 proteins is very similar to the carbohydrate recognition domain of C-type lectin proteins.

  18. The chemical defensome: environmental sensing and response genes in the Strongylocentrotus purpuratus genome.

    PubMed

    Goldstone, J V; Hamdoun, A; Cole, B J; Howard-Ashby, M; Nebert, D W; Scally, M; Dean, M; Epel, D; Hahn, M E; Stegeman, J J

    2006-12-01

    Metazoan genomes contain large numbers of genes that participate in responses to environmental stressors. We surveyed the sea urchin Strongylocentrotus purpuratus genome for homologs of gene families thought to protect against chemical stressors; these genes collectively comprise the 'chemical defensome.' Chemical defense genes include cytochromes P450 and other oxidases, various conjugating enzymes, ATP-dependent efflux transporters, oxidative detoxification proteins, and transcription factors that regulate these genes. Together such genes account for more than 400 genes in the sea urchin genome. The transcription factors include homologs of the aryl hydrocarbon receptor, hypoxia-inducible factor, nuclear factor erythroid-derived 2, heat shock factor, and nuclear hormone receptors, which regulate stress-response genes in vertebrates. Some defense gene families, including the ABCC, the UGT, and the CYP families, have undergone expansion in the urchin relative to other deuterostome genomes, whereas the stress sensor gene families do not show such expansion. More than half of the defense genes are expressed during embryonic or larval life stages, indicating their importance during development. This genome-wide survey of chemical defense genes in the sea urchin reveals evolutionary conservation of this network combined with lineage-specific diversification that together suggest the importance of these chemical stress sensing and response mechanisms in early deuterostomes. These results should facilitate future studies on the evolution of chemical defense gene networks and the role of these networks in protecting embryos from chemical stress during development.

  19. Expression of two actin genes during larval development in the sea urchin Strongylocentrotus purpuratus.

    PubMed

    Cameron, R A; Britten, R J; Davidson, E H

    1989-01-01

    We report the first measurements of cell number, total RNA, and transcript accumulations for two actin genes during larval development of the sea urchin Strongylocentrotus purpuratus. At 5 weeks of feeding, when development of laboratory-raised larvae is completed, the cell number has increased about 100-fold with respect to the pluteus-stage embryo to about 150,000 +/- 50,000, and the total RNA has increased 46-fold to about 130 ng per larva. The transcripts of the Cylla cytoskeletal actin gene, which is expressed in adult tissues, continue to accumulate throughout larval development. A contrasting pattern of transcript accumulation is observed for Cyllla, a different cytoskeletal actin gene that in the embryo is expressed only in aboral ectoderm. These transcripts increase in number early in larval development, when the larval epidermis is differentiating, and then decline in quantity. It is known that at metamorphosis the larval epidermis is largely histolyzed and that the Cyllla gene is not expressed in the juvenile or adult.

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

    PubMed

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

    2006-12-01

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

  1. Age-related changes in gene expression in tissues of the sea urchin Strongylocentrotus purpuratus.

    PubMed

    Loram, Jeannette; Bodnar, Andrea

    2012-05-01

    The life history of sea urchins is fundamentally different from that of traditional models of aging and therefore they provide the opportunity to gain new insight into this complex process. Sea urchins grow indeterminately, reproduce throughout their life span and some species exhibit negligible senescence. Using a microarray and qRT-PCR, age-related changes in gene expression were examined in three tissues (muscle, esophagus and nerve) of the sea urchin species Strongylocentrotus purpuratus. The results indicate age-related changes in gene expression involving many key cellular functions such as the ubiquitin-proteasome pathway, DNA metabolism, signaling pathways and apoptosis. Although there are tissue-specific differences in the gene expression profiles, there are some characteristics that are shared between tissues providing insight into potential mechanisms that promote lack of senescence in these animals. As an example, there is an increase in expression of genes encoding components of the Notch signaling pathway with age in all three tissues and a decrease in expression of the Wnt1 gene in both muscle and nerve. The interplay between the Notch and Wnt pathways may be one mechanism that ensures continued regeneration of tissues with advancing age contributing to the general lack of age-related decline in these animals.

  2. Cloning and characterization of alphaP integrin in embryos of the sea urchin Strongylocentrotus purpuratus.

    PubMed

    Susan, J M; Just, M L; Lennarz, W J

    2000-06-16

    Differentially expressed integrins have been shown to be involved in the intricate cell movements that occur during early development. Because the migration and movement of cells have been well characterized in sea urchin embryos, we searched for alpha-integrin subunits in this organism. An alpha integrin subunit, alphaP, was cloned from Strongylocentrotus purpuratus mesenchyme blastula stage mRNA by RT-PCR and RACE and found to exhibit 74-77% sequence similarity to mammalian alpha(5), alpha(8), alpha(IIb), and alpha(v) integrin. The 8-kb transcript was most abundant at the prism stage, although low levels could be detected at all stages by Northern blot analysis and RT-PCR. A polyclonal antibody to this novel integrin was generated against a 100-amino-acid alphaP fragment fused to glutathione S-transferase and shown to recognize a 180-kDa alpha-integrin in the egg and in all stages of embryogenesis studied.

  3. Effects of seawater acidification on cell cycle control mechanisms in Strongylocentrotus purpuratus embryos.

    PubMed

    Place, Sean P; Smith, Bryan W

    2012-01-01

    Previous studies have shown fertilization and development of marine species can be significantly inhibited when the pH of sea water is artificially lowered. Little mechanistic understanding of these effects exists to date, but previous work has linked developmental inhibition to reduced cleavage rates in embryos. To explore this further, we tested whether common cell cycle checkpoints were involved using three cellular biomarkers of cell cycle progression: (1) the onset of DNA synthesis, (2) production of a mitotic regulator, cyclin B, and (3) formation of the mitotic spindle. We grew embryos of the purple sea urchin, Strongylocentrotus purpuratus, in seawater artifically buffered to a pH of ∼7.0, 7.5, and 8.0 by CO(2) infusion. Our results suggest the reduced rates of mitotic cleavage are likely unrelated to common cell cycle checkpoints. We found no significant differences in the three biomarkers assessed between pH treatments, indicating the embryos progress through the G(1)/S, G(2)/M and metaphase/anaphase transitions at relatively similar rates. These data suggest low pH environments may not impact developmental programs directly, but may act through secondary mechanisms such as cellular energetics.

  4. Neurosensory and neuromuscular organization in tube feet of the sea urchin Strongylocentrotus purpuratus.

    PubMed

    Agca, Cavit; Elhajj, Milad C; Klein, William H; Venuti, Judith M

    2011-12-01

    Several behavioral and electrophysiological studies indicate that all classes of echinoderms, including Echinoidia, the class to which sea urchins belong, are photosensitive and exhibit complex behavioral responses to light or changes in light intensity. However, no discrete photosensitive structure has been identified in sea urchins. The purpose of this study was to provide new insights into eye evolution by determining whether distinct photosensory structures are present in adult sea urchins. Recently, we showed that the Strongylocentrotus purpuratus genome contains orthologs of many mammalian retinal genes and that these genes are expressed in tube feet, suggesting the presence of photoreceptor neurons. To determine whether this is so, we identified several features of tube feet that relate to a possible invertebrate phototransduction system. We show that rhabdomeric opsin is expressed severalfold higher within the disk region of the tube feet and is the most abundant opsin. Immunostaining identified βIII-tubulin-expressing cells at the periphery of disk in the vicinity of the synaptotagmin-expressing nerve fibers. We also showed that Pax6 expression in the disk was restricted to the periphery, where small clusters of putative sensory neurons reside. Our results reveal neuromuscular organization of the tube foot neuromuscular system. They further support earlier studies suggesting the presence of a photosensory system in tube feet.

  5. [Jean-Baptiste de Lamarck (1744-1829). A dispute on the mechanism of evolution. On the bicentenary of the publication of Philosophie Zoologique (1809)].

    PubMed

    Bednarczyk, Andrzej

    2009-01-01

    The author of the paper has made an attempt to prove that a teleological interpretation of Lamarck's theory is false. It is unwarranted to attribute to Lamarck the idea that a living organism has an internal tendency to complicate its organization and to improve its mode of functioning; such a concept is not confirmed by existing textual evidence, and it is also in direct conflict with Lamarck's undisputed mechanicism. The proof presented in the paper begins with an outline of the history of this false interpretation, including the opinions of Charles Lyell and Charles Darwin. As the tendency is ascribed also to nature itself, the next phase of the proof has involved reconstructing the fully ateleological notion of nature to which Lamarck subscribed. Supposed evidence for the tendency is said to be provided by the existence of a series in which the organization of a living body grows from the simplest to the most complex. That is why the author of the current paper has analysed the concept of série animale used by Lamarck in some detail, in order to demonstrate that it is typological in character, and has nothing to do with the tendency that is allegedly inherent in the nature of an organism. Also presented in the paper, in connection with the construction of the series, is the problem of spontaneous generation, which was made complicated by Lamarck. Finally, the very notion of tendency is analysed and confronted with Lamarck's text; the latter in fact does not contain any explanations that would be teleological in the strict sense of the word. The analysis has enabled the author of the current paper to conduct an exegesis of the fragment of Lamarck's text which might give grounds to it being construed in terms of an explanation resorting to the notion of tendency, and possible interpretations of that fragment have been presented. The paper ends with a description of the mechanism which, according to Lamarck, is responsible for the rise in complexity of an

  6. Early developmental gene regulation in Strongylocentrotus purpuratus embryos in response to elevated CO₂ seawater conditions.

    PubMed

    Hammond, LaTisha M; Hofmann, Gretchen E

    2012-07-15

    Ocean acidification, or the increased uptake of CO(2) by the ocean due to elevated atmospheric CO(2) concentrations, may variably impact marine early life history stages, as they may be especially susceptible to changes in ocean chemistry. Investigating the regulatory mechanisms of early development in an environmental context, or ecological development, will contribute to increased understanding of potential organismal responses to such rapid, large-scale environmental changes. We examined transcript-level responses to elevated seawater CO(2) during gastrulation and the initiation of spiculogenesis, two crucial developmental processes in the purple sea urchin, Strongylocentrotus purpuratus. Embryos were reared at the current, accepted oceanic CO(2) concentration of 380 microatmospheres (μatm), and at the elevated levels of 1000 and 1350 μatm, simulating predictions for oceans and upwelling regions, respectively. The seven genes of interest comprised a subset of pathways in the primary mesenchyme cell gene regulatory network (PMC GRN) shown to be necessary for the regulation and execution of gastrulation and spiculogenesis. Of the seven genes, qPCR analysis indicated that elevated CO(2) concentrations only had a significant but subtle effect on two genes, one important for early embryo patterning, Wnt8, and the other an integral component in spiculogenesis and biomineralization, SM30b. Protein levels of another spicule matrix component, SM50, demonstrated significant variable responses to elevated CO(2). These data link the regulation of crucial early developmental processes with the environment that these embryos would be developing within, situating the study of organismal responses to ocean acidification in a developmental context.

  7. Critical tissue copper residues for marine bivalve (Mytilus galloprovincialis) and echinoderm (Strongylocentrotus purpuratus) embryonic development: conceptual, regulatory and environmental implications.

    PubMed

    Rosen, Gunther; Rivera-Duarte, Ignacio; Chadwick, D Bart; Ryan, Adam; Santore, Robert C; Paquin, Paul R

    2008-09-01

    Critical tissue copper (Cu) residues associated with adverse effects on embryo-larval development were determined for the Mediterranean mussel (Mytilus galloprovincialis) and purple sea urchin (Strongylocentrotus purpuratus) following laboratory exposure to Cu-spiked seawater collected from San Diego Bay, California, USA. Whole body no-observed-effect-residues (NOER) were similar, with means of 21 and 23 microg g(-1) dw, for M. galloprovincialis and S. purpuratus, respectively. Mean whole body median effect residues (ER50) were 49 and 142 microg g(-1) dw for M. galloprovincialis and S. purpuratus, respectively. The difference in ER50s between species was reduced to a factor of <2 when expressed as soft tissue residues. Coefficients of variation among whole body-ER50s were 3-fold lower than median waterborne effect concentrations (EC50) for both species exposed to samples varying in water quality characteristics. This suggests that tissue concentrations were a better predictor of toxicity than water concentrations. The CBRs described herein do not differentiate between the internal Cu concentrations that are metabolically available and those that are accumulated and then detoxified. They do appear, however, to be well enough related to the level of accumulation at the site of action of toxicity that they serve as useful surrogates for the copper concentration that affects embryonic development of the species tested. Results presented have potentially important implications for a variety of monitoring and assessment strategies. These include regulatory approaches for deriving saltwater ambient water quality criteria for Cu, contributions towards the development of a saltwater biotic ligand model, the conceptual approach of using CBRs, and ecological risk assessment.

  8. Elimination of 2,4,5,2',4',5'-hexachlorobiphenyl by the purple sea urchin, Strongylocentrotus purpuratus, following single exposure

    SciTech Connect

    Tjeerdema, R.S.; Jacobs, R.S.

    1987-06-01

    Understanding the fate of a single PCB isomer in a resident species may aid in assessing the risk to the marine community. Therefore, the elimination of 2,4,5,2',4',5'-hexachlorobiphenyl (HCBP) by the purple sea urchin, Strongylocentrotus purpuratus, following a single exposure, was investigated. The purple sea urchin was chosen because of its economic importance and ability to proliferate in certain polluted conditions. Single exposure may best mimic the effects of intermittent oceanic incineration or disposal, and 2,4,5,2',4',5'-HCBP was chosen due to its presence in common PCB mixtures and high chlorine content, thus strong lipophilicity.

  9. The next evolutionary synthesis: from Lamarck and Darwin to genomic variation and systems biology.

    PubMed

    Bard, Jonathan Bl

    2011-11-03

    The evolutionary synthesis, the standard 20th century view of how evolutionary change occurs, is based on selection, heritable phenotypic variation and a very simple view of genes. It is therefore unable to incorporate two key aspects of modern molecular knowledge: first is the richness of genomic variation, so much more complicated than simple mutation, and second is the opaque relationship between the genotype and its resulting phenotype. Two new and important books shed some light on how we should view evolutionary change now. "Evolution: a view from the 21st century" by J.A. Shapiro (2011, FT Press Science, New Jersey, USA. pp. 246) examines the richness of genomic variation and its implications. "Transformations of Lamarckism: from Subtle Fluids to Molecular Biology" edited by S.B. Gissis & E. Jablonka (2011, MIT Press, Cambridge, USA. pp. 457) includes some 40 papers that anyone with an interest in the history of evolutionary thought and the relationship between the environment and the genome will want to read. This review discusses both books within the context of contemporary evolutionary thinking and points out that neither really comes to terms with today's key systems-biology question: how does mutation-induced variation in a molecular network generate variation in the resulting phenotype?

  10. Redescription of Dicyemennea eledones (Wagener, 1857) (Phylum Dicyemida) from Eledone cirrhosa (Lamarck, 1798) (Mollusca: Cephalopoda: Octopoda).

    PubMed

    Souidenne, Dhikra; Florent, Isabelle; Dellinger, Marc; Romdhane, Mohamed Salah; Grellier, Philippe; Furuya, Hidetaka

    2016-11-01

    Dicyemids are common parasites found in the kidneys of many cephalopods. Species identification previously relied on old species descriptions containing considerable confusions, casting doubt on taxonomy and identification. Detailed morphological description and genotyping of all developmental stages are required for an exact taxonomy. To this end, we undertook the redescription of the dicyemid Dicyemennea eledones (Wagener, 1857), infecting the cephalopod Eledone cirrhosa (Lamarck). Samples were collected off Concarneau in the Bay of Biscay, France, and off La Goulette in the Gulf of Tunis, Tunisia. Dicyemennea eledones is a large species, with adults reaching c.7,000 μm in length. The vermiform stages are characterised by having 23 peripheral cells, a conical calotte and an axial cell that extends to the base of the propolar cells. An anterior abortive axial cell is present in vermiform embryos. Infusoriform embryos consist of 37 cells; a single nucleus is present in each urn cell and the refringent bodies, which were not always seen, are possibly liquid. For the first time, an 18S rDNA sequence is generated for D. eledones, illustrating genetic differences with the other dicyemid 18S rDNA sequences available in databases. This sequence can now be used for D. eledones barcoding, making the identification of the species easier and more reliable.

  11. Influence of copper on the feeding rate, growth and reproduction of the golden apple snail, Pomacea canaliculata Lamarck.

    PubMed

    Peña, Silvia C; Pocsidio, Glorina N

    2007-12-01

    The influence of copper on feeding rate, growth, and reproduction of Pomacea canaliculata Lamarck was evaluated. Ten days of exposure to copper of relatively high concentration (67.5 microg/L) reduced the snails' feeding rate and retarded their growth. Exposure to 20 microg/L after 36 days increased feeding rate to 28%. After 20 days of exposure at 30 microg/L, snail's growth was significant but thereafter declined. Growth of all snails including control was negligible by day 50 when snails were in the reproductive state. Copper did not affect reproduction.

  12. Manipulation of Developing Juvenile Structures in Purple Sea Urchins (Strongylocentrotus purpuratus) by Morpholino Injection into Late Stage Larvae

    PubMed Central

    2014-01-01

    Sea urchins have been used as experimental organisms for developmental biology for over a century. Yet, as is the case for many other marine invertebrates, understanding the development of the juveniles and adults has lagged far behind that of their embryos and larvae. The reasons for this are, in large part, due to the difficulty of experimentally manipulating juvenile development. Here we develop and validate a technique for injecting compounds into juvenile rudiments of the purple sea urchin, Strongylocentrotus purpuratus. We first document the distribution of rhodaminated dextran injected into different compartments of the juvenile rudiment of sea urchin larvae. Then, to test the potential of this technique to manipulate development, we injected Vivo-Morpholinos (vMOs) designed to knock down p58b and p16, two proteins involved in the elongation of S. purpuratus larval skeleton. Rudiments injected with these vMOs showed a delay in the growth of some juvenile skeletal elements relative to controls. These data provide the first evidence that vMOs, which are designed to cross cell membranes, can be used to transiently manipulate gene function in later developmental stages in sea urchins. We therefore propose that injection of vMOs into juvenile rudiments, as shown here, is a viable approach to testing hypotheses about gene function during development, including metamorphosis. PMID:25436992

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

    PubMed

    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.

  14. Manipulation of developing juvenile structures in purple sea urchins (Strongylocentrotus purpuratus) by morpholino injection into late stage larvae.

    PubMed

    Heyland, Andreas; Hodin, Jason; Bishop, Cory

    2014-01-01

    Sea urchins have been used as experimental organisms for developmental biology for over a century. Yet, as is the case for many other marine invertebrates, understanding the development of the juveniles and adults has lagged far behind that of their embryos and larvae. The reasons for this are, in large part, due to the difficulty of experimentally manipulating juvenile development. Here we develop and validate a technique for injecting compounds into juvenile rudiments of the purple sea urchin, Strongylocentrotus purpuratus. We first document the distribution of rhodaminated dextran injected into different compartments of the juvenile rudiment of sea urchin larvae. Then, to test the potential of this technique to manipulate development, we injected Vivo-Morpholinos (vMOs) designed to knock down p58b and p16, two proteins involved in the elongation of S. purpuratus larval skeleton. Rudiments injected with these vMOs showed a delay in the growth of some juvenile skeletal elements relative to controls. These data provide the first evidence that vMOs, which are designed to cross cell membranes, can be used to transiently manipulate gene function in later developmental stages in sea urchins. We therefore propose that injection of vMOs into juvenile rudiments, as shown here, is a viable approach to testing hypotheses about gene function during development, including metamorphosis.

  15. Early Exposure of Bay Scallops (Argopecten irradians) to High CO2 Causes a Decrease in Larval Shell Growth

    PubMed Central

    White, Meredith M.; McCorkle, Daniel C.; Mullineaux, Lauren S.; Cohen, Anne L.

    2013-01-01

    Ocean acidification, characterized by elevated pCO2 and the associated decreases in seawater pH and calcium carbonate saturation state (Ω), has a variable impact on the growth and survival of marine invertebrates. Larval stages are thought to be particularly vulnerable to environmental stressors, and negative impacts of ocean acidification have been seen on fertilization as well as on embryonic, larval, and juvenile development and growth of bivalve molluscs. We investigated the effects of high CO2 exposure (resulting in pH = 7.39, Ωar = 0.74) on the larvae of the bay scallop Argopecten irradians from 12 h to 7 d old, including a switch from high CO2 to ambient CO2 conditions (pH = 7.93, Ωar = 2.26) after 3 d, to assess the possibility of persistent effects of early exposure. The survival of larvae in the high CO2 treatment was consistently lower than the survival of larvae in ambient conditions, and was already significantly lower at 1 d. Likewise, the shell length of larvae in the high CO2 treatment was significantly smaller than larvae in the ambient conditions throughout the experiment and by 7 d, was reduced by 11.5%. This study also demonstrates that the size effects of short-term exposure to high CO2 are still detectable after 7 d of larval development; the shells of larvae exposed to high CO2 for the first 3 d of development and subsequently exposed to ambient CO2 were not significantly different in size at 3 and 7 d than the shells of larvae exposed to high CO2 throughout the experiment. PMID:23596514

  16. Quantitative functional interrelations within the cis-regulatory system of the S. purpuratus Endo16 gene.

    PubMed

    Yuh, C H; Moore, J G; Davidson, E H

    1996-12-01

    Embryonic expression of the Endo16 gene of Strongylocentrotus purpuratus is controlled by interactions with at least 13 different DNA-binding factors. These interactions occur within a cis-regulatory domain that extends about 2300 bp upstream from the transcription start site. A recent functional characterization of this domain reveals six different subregions, or cis-regulatory modules, each of which displays a specific regulatory subfunction when linked with the basal promoter and in some cases various other modules (C.-H. Yuh and E. Davidson (1996) Development 122, 1069-1082). In the present work, we analyzed quantitative time-course measurements of the CAT enzyme output of embryos bearing expression constructs controlled by various Endo16 regulatory modules, either singly or in combination. Three of these modules function positively in that, in isolation, each is capable of promoting expression in vegetal plate and adjacent cell lineages, though with different temporal profiles of activity. Models for the mode of interaction of the three positive modules with one another were tested by assuming mathematical relations that would generate, from the measured single module time courses, the experimentally observed profiles of activity obtained when the relevant modules are physically linked in the same construct. The generated and observed time functions were compared, and the differences were minimized by least squares adjustment of a scale parameter. When the modules were tested in context of the endogenous promoter region, one of the positive modules (A) was found to increase the output of the others (B and G), by a constant factor. In contrast, a solution in which the time-course data of modules A and B are multiplied by one another was required for the interrelations of the positive modules when a minimal SV40 promoter was used. One interpretation is that, in this construct, each module independently stimulates the basal transcription complex. We used a

  17. Identification and characterization of homeobox transcription factor genes in Strongylocentrotus purpuratus, and their expression in embryonic development.

    PubMed

    Howard-Ashby, Meredith; Materna, Stefan C; Brown, C Titus; Chen, Lili; Cameron, R Andrew; Davidson, Eric H

    2006-12-01

    A set of 96 homeobox transcription factors was identified in the Strongylocentrotus purpuratus genome using permissive blast searches with a large collection of authentic homeodomain sequences from mouse, human and fly. A phylogenetic tree was constructed to compare the sea urchin homeobox gene family to those of vertebrates, with the result that with the only a few exceptions, orthologs of all vertebrate homeodomain genes were uncovered by our search. QPCR time course measurements revealed that 65% of these genes are expressed within the first 48 h of development (late gastrula). For genes displaying sufficiently high levels of transcript during the first 24 h of development (late blastula), whole mount in situ hybridization was carried out up to 48 h to determine spatial patterns of expression. The results demonstrate that homeodomain transcription factors participate in multiple and diverse developmental functions, in that they are used at a range of time points and in every territory of the developing embryo.

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

    PubMed Central

    2010-01-01

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

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

    SciTech Connect

    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.

  20. Assortative mating drives linkage disequilibrium between sperm and egg recognition protein loci in the sea urchin Strongylocentrotus purpuratus.

    PubMed

    Stapper, Andres Plata; Beerli, Peter; Levitan, Don R

    2015-04-01

    Sperm and eggs have interacting proteins on their surfaces that influence their compatibility during fertilization. These proteins are often polymorphic within species, producing variation in gamete affinities. We first demonstrate the fitness consequences of various sperm bindin protein (Bindin) variants in the sea urchin Strongylocentrotus purpuratus, and assortative mating between males and females based on their sperm Bindin genotype. This empirical finding of assortative mating based on sperm Bindin genotype could arise by linkage disequilibrium (LD) between interacting sperm and egg recognition loci. We then examine sequence variation in eight exons of the sea urchin egg receptor for sperm Bindin (EBR1). We find little evidence of LD among the eight exons of EBR1, yet strong evidence for LD between sperm Bindin and EBR1 overall, and varying degrees of LD between sperm Bindin among the eight exons. We reject the alternate hypotheses of LD driven by shared evolutionary histories, population structure, or close physical linkage between these interacting loci on the genome. The most parsimonious explanation for this pattern of LD is that it represents selection driven by assortative mating based on interactions among these sperm and egg loci. These findings indicate the importance of ongoing sexual selection in the maintenance of protein polymorphisms and LD, and more generally highlight how LD can be used as an indication of current mate choice, as opposed to historic selection.

  1. What Is the Core Oscillator in the Speract-Activated Pathway of the Strongylocentrotus purpuratus Sperm Flagellum?

    PubMed Central

    Aguilera, Luis U.; Galindo, Blanca E.; Sánchez, Daniel; Santillán, Moisés

    2012-01-01

    Sperm chemotaxis has an important role in fertilization. Most of our knowledge regarding this phenomenon comes from studies in organisms whose fertilization occurs externally, like sea urchins. Sea urchin spermatozoa respond to sperm-activating peptides, which diffuse from the egg jelly coat and interact with their receptor in the flagellum, triggering several physiological responses: changes in membrane potential, intracellular pH, cyclic nucleotide levels, and intracellular Ca2+ concentration ([Ca2+]). In particular, flagellar [Ca2+] has been shown to oscillate. These [Ca2+] oscillations are correlated with changes in the flagellar shape and so with the regulation of the sperm swimming paths. In this study, we demonstrate, from a mathematical modeling perspective, that the reported speract-activated signaling pathway in Strongylocentrotus purpuratus (speract being a sperm-activating peptide specific to this species) has the necessary elements to replicate the reported [Ca2+] oscillations. We further investigate which elements of this signaling pathway constitute the core oscillator. PMID:22713563

  2. Nutrient uptake by marine invertebrates: cloning and functional analysis of amino acid transporter genes in developing sea urchins (Strongylocentrotus purpuratus).

    PubMed

    Meyer, Eli; Manahan, Donal T

    2009-08-01

    Transport of amino acids from low concentrations in seawater by marine invertebrates has been extensively studied, but few of the genes involved in this physiological process have been identified. We have characterized three amino acid transporter genes cloned from embryos of the sea urchin Strongylocentrotus purpuratus. These genes show phylogenetic proximity to classical amino acid transport systems, including Gly and B0+, and the inebriated gene (INE). Heterologous expression of these genes in frog oocytes induced a 40-fold increase in alanine transport above endogenous levels, demonstrating that these genes mediate alanine transport. Antibodies specific to one of these genes (Sp-AT1) inhibited alanine transport, confirming the physiological activity of this gene in larvae. Whole-mount antibody staining of larvae revealed expression of Sp-AT1 in the ectodermal tissues associated with amino acid transport, as independently demonstrated by autoradiographic localization of radioactive alanine. Maximum rates of alanine transport increased 6-fold during early development, from embryonic to larval stages. Analysis of gene expression during this developmental period revealed that Sp-AT1 transcript abundance remained nearly constant, while that of another transporter gene (Sp-AT2) increased 11-fold. The functional characterization of these genes establishes a molecular biological basis for amino acid transport by developmental stages of marine invertebrates.

  3. Population genetics of cis-regulatory sequences that operate during embryonic development in the sea urchin Strongylocentrotus purpuratus.

    PubMed

    Garfield, David; Haygood, Ralph; Nielsen, William J; Wray, Gregory A

    2012-01-01

    Despite the fact that noncoding sequences comprise a substantial fraction of functional sites within all genomes, the evolutionary mechanisms that operate on genetic variation within regulatory elements remain poorly understood. In this study, we examine the population genetics of the core, upstream cis-regulatory regions of eight genes (AN, CyIIa, CyIIIa, Endo16, FoxB, HE, SM30 a, and SM50) that function during the early development of the purple sea urchin, Strongylocentrotus purpuratus. Quantitative and qualitative measures of segregating variation are not conspicuously different between cis-regulatory and closely linked "proxy neutral" noncoding regions containing no known functional sites. Length and compound mutations are common in noncoding sequences; conventional descriptive statistics ignore such mutations, under-representing true genetic variation by approximately 28% for these loci in this population. Patterns of variation in the cis-regulatory regions of six of the genes examined (CyIIa, CyIIIa, Endo16, FoxB, AN, and HE) are consistent with directional selection. Genetic variation within annotated transcription factor binding sites is comparable to, and frequently greater than, that of surrounding sequences. Comparisons of two paralog pairs (CyIIa/CyIIIa and AN/HE) suggest that distinct evolutionary processes have operated on their cis-regulatory regions following gene duplication. Together, these analyses provide a detailed view of the evolutionary mechanisms operating on noncoding sequences within a natural population, and underscore how little is known about how these processes operate on cis-regulatory sequences.

  4. Temperature and CO(2) additively regulate physiology, morphology and genomic responses of larval sea urchins, Strongylocentrotus purpuratus.

    PubMed

    Padilla-Gamiño, Jacqueline L; Kelly, Morgan W; Evans, Tyler G; Hofmann, Gretchen E

    2013-05-22

    Ocean warming and ocean acidification, both consequences of anthropogenic production of CO2, will combine to influence the physiological performance of many species in the marine environment. In this study, we used an integrative approach to forecast the impact of future ocean conditions on larval purple sea urchins (Strongylocentrotus purpuratus) from the northeast Pacific Ocean. In laboratory experiments that simulated ocean warming and ocean acidification, we examined larval development, skeletal growth, metabolism and patterns of gene expression using an orthogonal comparison of two temperature (13°C and 18°C) and pCO2 (400 and 1100 μatm) conditions. Simultaneous exposure to increased temperature and pCO2 significantly reduced larval metabolism and triggered a widespread downregulation of histone encoding genes. pCO2 but not temperature impaired skeletal growth and reduced the expression of a major spicule matrix protein, suggesting that skeletal growth will not be further inhibited by ocean warming. Importantly, shifts in skeletal growth were not associated with developmental delay. Collectively, our results indicate that global change variables will have additive effects that exceed thresholds for optimized physiological performance in this keystone marine species.

  5. The C2H2 zinc finger genes of Strongylocentrotus purpuratus and their expression in embryonic development.

    PubMed

    Materna, Stefan C; Howard-Ashby, Meredith; Gray, Rachel F; Davidson, Eric H

    2006-12-01

    The C2H2 zinc finger is one of the most abundant protein domains and is thought to have been extensively replicated in diverse animal clades. Some well-studied proteins that contain this domain are transcriptional regulators. As part of an attempt to delineate all transcription factors encoded in the Strongylocentrotus purpuratus genome, we identified the C2H2 zinc finger genes indicated in the sequence, and examined their involvement in embryonic development. We found 377 zinc finger genes in the sea urchin genome, about half the number found in mice or humans. Their expression was measured by quantitative PCR. Up to the end of gastrulation less than a third of these genes is expressed, and about 75% of the expressed genes are maternal; both parameters distinguish these from all other classes of regulatory genes as measured in other studies. Spatial expression pattern was determined by whole mount in situ hybridization for 43 genes transcribed at a sufficient level, and localized expression was observed in diverse embryonic tissues. These genes may execute important regulatory functions in development. However, the functional meaning of the majority of this large gene family remains undefined.

  6. Comparative analysis of fibrillar and basement membrane collagen expression in embryos of the sea urchin, Strongylocentrotus purpuratus.

    PubMed

    Suzuki, H R; Reiter, R S; D'Alessio, M; Di Liberto, M; Ramirez, F; Exposito, J Y; Gambino, R; Solursh, M

    1997-06-01

    The time of appearance and location of three distinct collagen gene transcripts termed 1 alpha, 2 alpha, and 3 alpha, were monitored in the developing S. purpuratus embryo by in situ hybridization. The 1 alpha and 2 alpha transcripts of fibrillar collagens were detected simultaneously in the primary (PMC) and secondary (SMC) mesenchyme cells of the late gastrula stage and subsequently expressed in the spicules and gut associated cells of the pluteus stage. The 3 alpha transcripts of the basement membrane collagen appeared earlier than 1 alpha and 2 alpha, and were first detected in the presumptive PMC at the vegetal plate of the late blastula stage. The PMC exhibited high expression of 3 alpha at the mesenchyme blastula stage, but during gastrulation the level of expression was reduced differentially among the PMC. In the late gastrula and pluteus stages, both PMC and SMC expressed 3 alpha mRNA, and thus at these stages all three collagen genes displayed an identical expression pattern by coincidence. This study thus provides the first survey of onset and localization of multiple collagen transcripts in a single sea urchin species.

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

    NASA Astrophysics Data System (ADS)

    LaVigne, M.; Hill, T. M.; Sanford, E.; Gaylord, B.; Russell, A. D.; Lenz, E. A.; Hosfelt, J. D.; Young, M. K.

    2012-12-01

    Ocean acidification will likely have negative impacts on invertebrates producing skeletons composed of calcium carbonate. Skeletal solubility is partly controlled by the incorporation of "foreign" ions (such as Mg and Sr) into the crystal lattice of these skeletal structures, a process that is sensitive to a variety of biological and environmental factors. Here we explore the effects of life stage, oceanographic region of origin, and changes in the partial pressure of carbon dioxide in seawater (pCO2) on trace elemental composition in the purple sea urchin (Strongylocentrotus purpuratus). We show that, similar to other urchin taxa, adult purple sea urchins have the ability to precipitate skeleton composed of a range of biominerals spanning low to high magnesium calcites. Mg/Ca and Sr/Ca ratios were substantially lower in adult spines compared to adult tests. On the other hand, trace elemental composition was invariant among adults collected from four oceanographically distinct regions along the US west coast (Oregon, Northern California, Central California, and Southern California). Skeletons of newly settled juvenile urchins that originated from adults from the four regions exhibited intermediate Mg/Ca and Sr/Ca between adult spine and test endmembers, indicating that skeleton precipitated during early life stages is more soluble than adult spines and less soluble than adult tests. Mean skeletal Mg/Ca or Sr/Ca of juvenile skeleton did not vary with source region when larvae were reared under present-day, global-average seawater carbonate conditions (400 ppm; pH = 8.02 ± 0.03 1 SD; Ωcalcite = 3.3 ± 0.2 1 SD). However, when reared under elevated CO2 (900 ppm; pH = 7.72 ± 0.03; Ωcalcite = 1.8 ± 0.1), skeletal Sr/Ca in juveniles exhibited increased variance across the four regions. Although larvae from the northern populations (Oregon, Northern California, Central California) did not exhibit differences in Mg or Sr incorporation under elevated CO2 (Sr/Ca = 2

  8. Accumulation, Biotransformation, Histopathology and Paralysis in the Pacific Calico Scallop Argopecten ventricosus by the Paralyzing Toxins of the Dinoflagellate Gymnodinium catenatum

    PubMed Central

    Escobedo-Lozano, Amada Y.; Estrada, Norma; Ascencio, Felipe; Contreras, Gerardo; Alonso-Rodriguez, Rosalba

    2012-01-01

    The dinoflagellate Gymnodinium catenatum produces paralyzing shellfish poisons that are consumed and accumulated by bivalves. We performed short-term feeding experiments to examine ingestion, accumulation, biotransformation, histopathology, and paralysis in the juvenile Pacific calico scallop Argopecten ventricosus that consume this dinoflagellate. Depletion of algal cells was measured in closed systems. Histopathological preparations were microscopically analyzed. Paralysis was observed and the time of recovery recorded. Accumulation and possible biotransformation of toxins were measured by HPLC analysis. Feeding activity in treated scallops showed that scallops produced pseudofeces, ingestion rates decreased at 8 h; approximately 60% of the scallops were paralyzed and melanin production and hemocyte aggregation were observed in several tissues at 15 h. HPLC analysis showed that the only toxins present in the dinoflagellates and scallops were the N-sulfo-carbamoyl toxins (C1, C2); after hydrolysis, the carbamate toxins (epimers GTX2/3) were present. C1 and C2 toxins were most common in the mantle, followed by the digestive gland and stomach-complex, adductor muscle, kidney and rectum group, and finally, gills. Toxin profiles in scallop tissue were similar to the dinoflagellate; biotransformations were not present in the scallops in this short-term feeding experiment. PMID:22822356

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

    PubMed

    Foster, Matthew C; Byrnes, Jarrett E K; Reed, Daniel C

    2015-01-01

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

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

    SciTech Connect

    Krause, P.R. . Dept. of Biological Sciences)

    1994-07-01

    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.

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

    PubMed

    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.

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

    PubMed Central

    Byrnes, Jarrett E.K.; Reed, Daniel C.

    2015-01-01

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

  13. Two new species of poecilostomatoid copepods symbiotic on the venomous echinoid Toxopneustes pileolus (Lamarck) (Echinodermata) from Vietnam.

    PubMed

    Venmathi Maran, Balu Alagar; Kim, Il-Hoi; Bratova, Olga A; Ivanenko, Viatcheslav N

    2017-02-01

    Two new coexisting species of crustacean copepods (Poecilostomatoida) belonging to the echinoid-specific genera Mecomerinx Humes, 1977 (Pseudanthessiidae) and Clavisodalis Humes, 1970 (Taeniacanthidae) found associated with the venomous flower urchin Toxopneustes pileolus (Lamarck) (Echinodermata: Echinoidea: Toxopneustidae) in the South China Sea (Vietnam) are described. The diagnostic features of Mecomerinx ohtsukai n. sp. are: (i) three setae and one aesthetasc on the first segment of antennules; (ii) relatively long caudal ramus; (iii) elongated terminal segment of the antenna; and (iv) two claws on the terminal segment of antenna slightly unequal in length. The taeniacanthid copepod Clavisodalis toxopneusti n. sp. is distinguished from all seven known congeners by having two-segmented endopod of the legs 2-4 and four setae on the distal endopodal segment of the leg 1. This is the first report on copepods associated with echinoids of the genus Toxopneustes Agassiz and the first finding of Mecomerinx as well as taeniacanthid copepods in the South China Sea associated with echinoids.

  14. Seasonal variation of biochemical components in clam ( Saxidomus purpuratus Sowerby 1852) in relation to its reproductive cycle and the environmental condition of Sanggou Bay, China

    NASA Astrophysics Data System (ADS)

    Bi, Jinhong; Li, Qi; Zhang, Xinjun; Zhang, Zhixin; Tian, Jinling; Xu, Yushan; Liu, Wenguang

    2016-04-01

    Seasonal variation of biochemical components in clam ( Saxidomus purpuratus Sowerby 1852) was investigated from March 2012 to February 2013 in relation to environmental condition of Sanggou Bay and the reproductive cycle of clam. According to the histological analysis, the reproductive cycle of S. purpuratus includes two distinctive phases: a total spent and inactive stage from November to January, and a gametogenesis stage, including ripeness and spawning, during the rest of the year. Gametes were generated at a low temperature (2.1°C) in February. Spawning took place once a year from June to October. The massive spawning occurred in August when the highest water temperature and chlorophyll a level could be observed. The key biochemical components (glycogen, protein and lipid) in five tissues (gonad, foot, mantle, siphon and adductor muscle) were analyzed. The glycogen content was high before gametogenesis, and decreased significantly during the gonad development in the gonad, mantle and foot of both females and males, suggesting that glycogen was an important energy source for gonad development. The protein and lipid contents increased in the ovary during the gonad development, demonstrating that they are the major organic components of oocytes. The lipid and protein contents decreased in the testis, implying that they can provide energy and material for spermatogenesis. The results also showed that protein stored in the mantle and foot could support the reproduction after the glycogen was depleted.

  15. SpSM30 gene family expression patterns in embryonic and adult biomineralized tissues of the sea urchin, Strongylocentrotus purpuratus.

    PubMed

    Killian, Christopher E; Croker, Lindsay; Wilt, Fred H

    2010-01-01

    The SpSM30 gene family of the sea urchin, Strongylocentrotus purpuratus, is comprised of six members, designated SpSM30A through SpSM30F (Livingston et al., 2006). The SpSM30 proteins are found uniquely in embryonic and adult mineralized tissues of the sea urchin. Previous studies have revealed that SpSM30 proteins are occluded within the embryonic endoskeleton and adult mineralized tissues (Killian and Wilt, 1996; Mann et al., 2008a,b; Urry et al., 2000). Furthermore, some of the SpSM30 proteins are among the most abundant of the approximately four-dozen integral matrix proteins of the larval spicule (Killian and Wilt, 1996). The amino acid sequence, protein domain architecture, and contiguity within the genome strongly support the supposition that the six genes constitute a gene family. Reverse transcription-polymerase chain reaction (RT-PCR) is used in the present study to describe the time course of expression of the family members during embryonic development, and their expression in adult tissues. SpSM30A, B, C and E are expressed, albeit at different levels, during overt spicule deposition in the embryo with some differences in the precise timing of expression. SpSM30D is not expressed in the embryo, and SpSM30F is expressed transiently and at low levels just prior to overt spicule formation. Whole mount in situ hybridization studies show that SpSM30A, B, C, and E are expressed exclusively in primary mesenchyme (PMC) cells and their descendants. In addition, tissue fractionation studies indicate that SpSM30F expression is highly enriched in PMCs. Each adult tissue examined expresses a different cohort of the SpSM30 family members at varying levels: SpSM30A mRNA is not expressed in adult tissues. Its expression is limited to the embryo. Conversely, SpSM30D mRNA is not expressed in the embryo, but is expressed in adult spines and teeth. SpSM30B and SpSM30C are expressed at modest levels in all mineralized adult tissues; SpSM30E is expressed highly in tooth and

  16. Taxonomic revision and cladistic analysis of Avicularia Lamarck, 1818 (Araneae, Theraphosidae, Aviculariinae) with description of three new aviculariine genera.

    PubMed

    Fukushima, Caroline Sayuri; Bertani, Rogério

    2017-01-01

    The genus Avicularia Lamarck, 1818 is revised and all species are rediagnosed. The type species, described as Aranea avicularia Linnaeus, 1758, is the oldest mygalomorph species described and its taxonomic history is extensive and confusing. Cladistic analyses using both equal and implied weights were carried out with a matrix of 46 taxa from seven theraphosid subfamilies, and 71 morphological and ecological characters. The optimal cladogram found with Piwe and concavity = 6 suggests Avicularia and Aviculariinae are monophyletic. Subfamily Aviculariinae includes Avicularia Lamarck, 1818, Typhochlaena C. L. Koch, 1850, Tapinauchenius Ausserer, 1871, Stromatopelma Karsch, 1881, Ephebopus Simon, 1892, Psalmopoeus Pocock, 1895, Heteroscodra Pocock, 1899, Iridopelma Pocock, 1901, Pachistopelma Pocock, 1901, Ybyraporagen. n., Caribenagen. n., and Antillenagen. n. The clade is supported by well-developed scopulae on tarsi and metatarsi, greatly extended laterally. Avicularia synapomorphies are juveniles bearing black tarsi contrasting with other lighter articles; spermathecae with an accentuated outwards curvature medially, and male palpal bulb with embolus medial portion and tegulum's margin form an acute angle in retrolateral view. Avicularia is composed of twelve species, including three new species: Avicularia avicularia (Linnaeus, 1818), Avicularia glauca Simon, 1891, Avicularia variegata (F. O. Pickard-Cambridge, 1896) stat. n., Avicularia minatrix Pocock, 1903, Avicularia taunayi (Mello-Leitão, 1920), Avicularia juruensis Mello-Leitão, 1923, Avicularia rufa Schiapelli & Gerschman, 1945, Avicularia purpurea Kirk, 1990, Avicularia hirschii Bullmer et al. 2006, Avicularia merianaesp. n., Avicularia lynnaesp. n., and Avicularia caeisp. n.. Avicularia species are distributed throughout Mexico, Costa Rica, Panama, Trinidad and Tobago, Venezuela, Guyana, Suriname, French Guiana, Colombia, Ecuador, Peru, Bolivia, and Brazil. Three new genera are erected to accommodate

  17. A C-type lectin (AiCTL-3) from bay scallop Argopecten irradians with mannose/galactose binding ability to bind various bacteria.

    PubMed

    Huang, Mengmeng; Song, Xiaoyan; Zhao, Jianmin; Mu, Changkao; Wang, Lingling; Zhang, Huan; Zhou, Zhi; Liu, Xiaolin; Song, Linsheng

    2013-11-15

    C-type lectins are a family of Ca(2+)-dependent carbohydrate-binding proteins playing crucial roles in innate immunity of vertebrates and invertebrates. In the present study, the cDNA of a C-type lectin with one carbohydrate-recognition domain (CRD) of 127 amino acids was cloned from bay scallop Argopecten irradians (designated AiCTL-3) by rapid amplification of cDNA end (RACE) techniques based on expressed sequence tag (EST) analysis. The mRNA transcripts of AiCTL-3 could be detected in all the tested tissues including hepatopancreas, gonad, adductor muscle, heart, hemocytes, mantle and gill, with the highest expression level in hepatopancreas. After the challenges with Vibrio anguillarum and Micrococcus luteus, the mRNA expression level of AiCTL-3 was obviously up-regulated and reached the maximum level at 9h (11.87fold, P<0.01, and 20.02-fold, P<0.05, respectively). The recombinant AiCTL-3 (designated as rAiCTL-3) could bind LPS, PGN, and glucan in vitro, but could not bind mannan. And it also bound Gram-positive bacteria Staphylococcus aureus as well as Gram-negative bacteria Escherichia coli and V. anguillarum. With a Ca(2+) binding site 2 EPN (Glu-Pro-Asn) motif, rAiCTL-3 could bind both mannose and galactose which was quite different from those in vertebrate. Meanwhile, it could significantly enhance the phagocytosis of scallop hemocytes in vitro. The results clearly suggested that AiCTL-3 could serve not only as a PRR participated in the immune response against various PAMPs and bacteria in non-self recognition via mannose/galactose binding specificity but an opsonin playing an important part in clearance of invaders.

  18. Molecular cloning, expression of a big defensin gene from bay scallop Argopecten irradians and the antimicrobial activity of its recombinant protein.

    PubMed

    Zhao, Jianmin; Song, Linsheng; Li, Chenghua; Ni, Duojiao; Wu, Longtao; Zhu, Ling; Wang, Hao; Xu, Wei

    2007-01-01

    Antimicrobial peptides are important components of the host innate immune responses by exerting broad-spectrum microbicidal activity against pathogenic microbes. The first mollusk big defensin (designated AiBD) cDNA was cloned from bay scallop Argopecten irradians by expressed sequence tag (EST) and rapid amplification of cDNA ends (RACE) techniques. The scallop AiBD consisted of 531 nucleotides with a canonical polyadenylation signal sequence AATAAA and a poly(A) tail, encoding a polypeptide of 122 amino acids. The high similarity of AiBD deduced amino acid sequence with big defensin from Tachypleus tridentatus and Branchiostoma belcheri tsingtaunese indicated that AiBD should be a member of big defensin family. The expression of AiBD in various tissues was measured by using Northern blotting analysis. mRNA transcripts of AiBD could be detected in haemocytes of unchallenged scallops. The temporal expression of AiBD in haemolymph after Vibrio anguilarum challenge was recorded by quantitative real time PCR. The relative expression level of AiBD in haemolymph was up-regulated evenly in the first 8 h, followed by a drastic increase, and increased 131.1-fold at 32 h post-injection. These results indicated that AiBD could be induced by bacterial challenge, and it should participate in the immune responses of A. irradians. Biological activity assay revealed that recombinant AiBD could inhibit the growth of both Gram-positive and Gram-negative bacteria, and also showed strong fungicidal activity towards the expression host. Recombinant expression of AiBD made it possible to further characterize its functions involved in immune responses, and also provided a potential therapeutic agent for disease control in aquaculture.

  19. Unveiling the Rosetta Stone of syllids: redescription and neotype designation of Syllis monilaris Savigny in Lamarck, 1818, type species of type genus of family Syllidae Grube, 1850 (Annelida).

    PubMed

    Álvarez-Campos, Patricia; Gil, João; San Martín, Guillermo

    2015-11-11

    Syllis monilaris Savigny in Lamarck, 1818, the type species of the genus Syllis Savigny in Lamarck, 1818, is redescribed based on two specimens deposited in the Museum für Naturkunde Berlin (Germany). One specimen is designated as neotype, since the original type material is considered to be lost, and there is a necessity to stabilize the nomenclature of the group. The species is large sized, with long dorsal cirri on anterior segments, becoming short and fusiform from midbody, it has thick compound chaetae with short, unidentate blades, not fused to shafts. The lack of chaetae with fused shafts and blades contradicts the division of the genus Syllis into subgenera as proposed by Langerhans (1879), who considered the subgenus Syllis as having thick fused chaetae on midbody, in addition to compound chaetae, and the subgenus Typosyllis with only compound chaetae. A discussion about the systematics of the genus is included, and according to this new data, Typosyllis is a junior synonymy of Syllis.

  20. Genetic organization and embryonic expression of the ParaHox genes in the sea urchin S. purpuratus: insights into the relationship between clustering and colinearity.

    PubMed

    Arnone, Maria I; Rizzo, Francesca; Annunciata, Rosella; Cameron, R Andrew; Peterson, Kevin J; Martínez, Pedro

    2006-12-01

    The ANTP family of homeodomain transcription factors consists of three major groups, the NKL, the extended Hox, and the Hox/ParaHox family. Hox genes and ParaHox genes are often linked in the genome forming two clusters of genes, the Hox cluster and the ParaHox cluster, and are expressed along the major body axis in a nested fashion, following the relative positions of the genes within these clusters, a property called colinearity. While the presences of a Hox cluster and a ParaHox cluster appear to be primitive for bilaterians, few taxa have actually been examined for spatial and temporal colinearity, and, aside from chordates, even fewer still manifest it. Here we show that the ParaHox genes of the sea urchin Strongylocentrotus purpuratus show both spatial and temporal colinearity, but with peculiarities. Specifically, two of the three ParaHox genes-discovered through the S. purpuratus genome project-Sp-lox and Sp-Cdx, are expressed in the developing gut with nested domains in a spatially colinear manner. However, transcripts of Sp-Gsx, although anterior of Sp-lox, are detected in the ectoderm and not in the gut. Strikingly, the expression of the three ParaHox genes would follow temporal colinearity if they were clustered in the same order as in chordates, but each ParaHox gene is actually found on a different genomic scaffold (>300 kb each), which suggests that they are not linked into a single coherent cluster. Therefore, ParaHox genes are dispersed in the genome and are used during embryogenesis in a temporally and spatially coherent manner, whereas the Hox genes, now fully sequenced and annotated, are still linked and are employed as a complex only during the emergence of the adult body plan in the larva.

  1. A Consensus Microsatellite-Based Linkage Map for the Hermaphroditic Bay Scallop (Argopecten irradians) and Its Application in Size-Related QTL Analysis

    PubMed Central

    Li, Hongjun; Liu, Xiao; Zhang, Guofan

    2012-01-01

    Bay scallop (Argopecten irradians) is one of the most economically important aquaculture species in China. In this study, we constructed a consensus microsatellite-based genetic linkage map with a mapping panel containing two hybrid backcross-like families involving two subspecies of bay scallop, A. i. irradians and A. i. concentricus. One hundred sixty-one microsatellite and one phenotypic (shell color) markers were mapped to 16 linkage groups (LGs), which corresponds to the haploid chromosome number of bay scallop. The sex-specific map was 779.2 cM and 781.6 cM long in female and male, respectively, whereas the sex-averaged map spanned 849.3 cM. The average resolution of integrated map was 5.9 cM/locus and the estimated coverage was 81.3%. The proportion of distorted markers occurred more in the hybrid parents, suggesting that the segregation distortion was possibly resulted from heterospecific interaction between genomes of two subspecies of bay scallop. The overall female-to-male recombination rate was 1.13∶1 across all linked markers in common to both parents, and considerable differences in recombination also existed among different parents in both families. Four size-related traits, including shell length (SL), shell height (SH), shell width (SW) and total weight (TW) were measured for quantitative trait loci (QTL) analysis. Three significant and six suggestive QTL were detected on five LGs. Among the three significant QTL, two (qSW-10 and qTW-10, controlling SW and TW, respectively) were mapped on the same region near marker AiAD121 on LG10 and explained 20.5% and 27.7% of the phenotypic variance, while the third (qSH-7, controlling SH) was located on LG7 and accounted for 15.8% of the phenotypic variance. Six suggestive QTL were detected on four different LGs. The linkage map and size-related QTL obtained in this study may facilitate marker-assisted selection (MAS) in bay scallop. PMID:23077533

  2. Examining the Effects of Chromatic Aberration, Object Distance, and Eye Shape on Image-Formation in the Mirror-Based Eyes of the Bay Scallop Argopecten irradians.

    PubMed

    Speiser, Daniel I; Gagnon, Yakir Luc; Chhetri, Raghav K; Oldenburg, Amy L; Johnsen, Sönke

    2016-11-01

    The eyes of scallops form images using a concave spherical mirror and contain two separate retinas, one layered on top of the other. Behavioral and electrophysiological studies indicate that the images formed by these eyes have angular resolutions of about 2°. Based on previous ray-tracing models, it has been thought that the more distal of the two retinas lies near the focal point of the mirror and that the proximal retina, positioned closer to the mirror at the back of the eye, receives light that is out-of-focus. Here, we propose three mechanisms through which both retinas may receive focused light: (1) chromatic aberration produced by the lens may cause the focal points for longer and shorter wavelengths to fall near the distal and proximal retinas, respectively; (2) focused light from near and far objects may fall on the distal and proximal retinas, respectively; and (3) the eyes of scallops may be dynamic structures that change shape to determine which retina receives focused light. To test our hypotheses, we used optical coherence tomography (OCT), a method of near-infrared optical depth-ranging, to acquire virtual cross-sections of live, intact eyes from the bay scallop Argopecten irradians Next, we used a custom-built ray-tracing model to estimate the qualities of the images that fall on an eye's distal and proximal retinas as functions of the wavelengths of light entering the eye (400-700 nm), object distances (0.01-1 m), and the overall shape of the eye. When we assume 550 nm wavelength light and object distances greater than 0.01 m, our model predicts that the angular resolutions of the distal and proximal retinas are 2° and 7°, respectively. Our model also predicts that neither chromatic aberration nor differences in object distance lead to focused light falling on the distal and proximal retinas simultaneously. However, if scallops can manipulate the shapes of their eyes, perhaps through muscle contractions, we speculate that they may be able

  3. Taxonomic revision and cladistic analysis of Avicularia Lamarck, 1818 (Araneae, Theraphosidae, Aviculariinae) with description of three new aviculariine genera

    PubMed Central

    Fukushima, Caroline Sayuri; Bertani, Rogério

    2017-01-01

    Abstract The genus Avicularia Lamarck, 1818 is revised and all species are rediagnosed. The type species, described as Aranea avicularia Linnaeus, 1758, is the oldest mygalomorph species described and its taxonomic history is extensive and confusing. Cladistic analyses using both equal and implied weights were carried out with a matrix of 46 taxa from seven theraphosid subfamilies, and 71 morphological and ecological characters. The optimal cladogram found with Piwe and concavity = 6 suggests Avicularia and Aviculariinae are monophyletic. Subfamily Aviculariinae includes Avicularia Lamarck, 1818, Typhochlaena C. L. Koch, 1850, Tapinauchenius Ausserer, 1871, Stromatopelma Karsch, 1881, Ephebopus Simon, 1892, Psalmopoeus Pocock, 1895, Heteroscodra Pocock, 1899, Iridopelma Pocock, 1901, Pachistopelma Pocock, 1901, Ybyrapora gen. n., Caribena gen. n., and Antillena gen. n. The clade is supported by well-developed scopulae on tarsi and metatarsi, greatly extended laterally. Avicularia synapomorphies are juveniles bearing black tarsi contrasting with other lighter articles; spermathecae with an accentuated outwards curvature medially, and male palpal bulb with embolus medial portion and tegulum’s margin form an acute angle in retrolateral view. Avicularia is composed of twelve species, including three new species: Avicularia avicularia (Linnaeus, 1818), Avicularia glauca Simon, 1891, Avicularia variegata (F. O. Pickard-Cambridge, 1896) stat. n., Avicularia minatrix Pocock, 1903, Avicularia taunayi (Mello-Leitão, 1920), Avicularia juruensis Mello-Leitão, 1923, Avicularia rufa Schiapelli & Gerschman, 1945, Avicularia purpurea Kirk, 1990, Avicularia hirschii Bullmer et al. 2006, Avicularia merianae sp. n., Avicularia lynnae sp. n., and Avicularia caei sp. n.. Avicularia species are distributed throughout Mexico, Costa Rica, Panama, Trinidad and Tobago, Venezuela, Guyana, Suriname, French Guiana, Colombia, Ecuador, Peru, Bolivia, and Brazil. Three new genera are erected

  4. Measurements of mechanical properties of the blastula wall reveal which hypothesized mechanisms of primary invagination are physically plausible in the sea urchin Strongylocentrotus purpuratus.

    PubMed

    Davidson, L A; Oster, G F; Keller, R E; Koehl, M A

    1999-05-15

    Computer simulations showed that the elastic modulus of the cell layer relative to the elastic modulus of the extracellular layers predicted the effectiveness of different force-generating mechanisms for sea urchin primary invagination [L. A. Davidson, M. A. R. Koehl, R. Keller, and G. F. Oster (1995) Development 121, 2005-2018]. Here, we measured the composite elastic modulus of the cellular and extracellular matrix layers in the blastula wall of Strongylocentrotus purpuratus embryos at the mesenchyme blastula stage. Combined, these two layers exhibit a viscoelastic response with an initial stiffness ranging from 600 to 2300 Pa. To identify the cellular structures responsible for this stiffness we disrupted these structures and correlated the resulting lesions to changes in the elastic modulus. We treated embryos with cytochalasin D to disrupt the actin-based cytoskeleton, nocodazole to disrupt the microtubule-based cytoskeleton, and a gentle glycine extraction to disrupt the apical extracellular matrix (ECM). Embryos treated less than 60 min in cytochalasin D showed no change in their time-dependent elastic modulus even though F-actin was severely disrupted. Similarly, nocodazole had no effect on the elastic modulus even as the microtubules were severely disrupted. However, glycine extraction resulted in a 40 to 50% decrease in the elastic modulus along with a dramatic reduction in the hyalin protein at the apical ECM, thus implicating the apical ECM as a major mechanical component of the blastula wall. This finding bears on the mechanical plausibility of several models for primary invagination.

  5. Molecular phylogeny of the genus Taenia (Cestoda: Taeniidae): proposals for the resurrection of Hydatigera Lamarck, 1816 and the creation of a new genus Versteria.

    PubMed

    Nakao, Minoru; Lavikainen, Antti; Iwaki, Takashi; Haukisalmi, Voitto; Konyaev, Sergey; Oku, Yuzaburo; Okamoto, Munehiro; Ito, Akira

    2013-05-01

    The cestode family Taeniidae generally consists of two valid genera, Taenia and Echinococcus. The genus Echinococcus is monophyletic due to a remarkable similarity in morphology, features of development and genetic makeup. By contrast, Taenia is a highly diverse group formerly made up of different genera. Recent molecular phylogenetic analyses strongly suggest the paraphyly of Taenia. To clarify the genetic relationships among the representative members of Taenia, molecular phylogenies were constructed using nuclear and mitochondrial genes. The nuclear phylogenetic trees of 18S ribosomal DNA and concatenated exon regions of protein-coding genes (phosphoenolpyruvate carboxykinase and DNA polymerase delta) demonstrated that both Taenia mustelae and a clade formed by Taenia parva, Taenia krepkogorski and Taenia taeniaeformis are only distantly related to the other members of Taenia. Similar topologies were recovered in mitochondrial genomic analyses using 12 complete protein-coding genes. A sister relationship between T. mustelae and Echinococcus spp. was supported, especially in protein-coding gene trees inferred from both nuclear and mitochondrial data sets. Based on these results, we propose the resurrection of Hydatigera Lamarck, 1816 for T. parva, T. krepkogorski and T. taeniaeformis and the creation of a new genus, Versteria, for T. mustelae. Due to obvious morphological and ecological similarities, Taenia brachyacantha is also included in Versteria gen. nov., although molecular evidence is not available. Taenia taeniaeformis has been historically regarded as a single species but the present data clearly demonstrate that it consists of two cryptic species.

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

    NASA Astrophysics Data System (ADS)

    LaVigne, M.; Hill, T. M.; Sanford, E.; Gaylord, B.; Russell, A. D.; Lenz, E. A.; Hosfelt, J. D.; Young, M. K.

    2013-06-01

    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

  7. Effects of produced water on reproduction and early life stages of the purple sea urchin (Strongylocentrotus purpuratus): Field and laboratory tests

    SciTech Connect

    Krause, P.R.

    1993-01-01

    This dissertation focuses on the effects of produced water (an oil-production effluent) on reproduction in the purple sea urchin (Strongy-locentrotus purpuratus) using both field and laboratory experiments. The author investigated the effects of chronic exposure to produced water on the gametogenesis and gamete performance using an in-situ caging experiment. He found a significant negative relationship between gonad mass and cage distance for both sexes, indicating that urchins living closer to the outfall produced significantly larger gonads. He also found significant differences in the fertilizability of eggs between cages and this showed a positive relationship with distance from the outfall. These findings indicate that while urchins exposed to a produced water outfall produce large gonads, they suffer a marked decrease in gamete performance. In a subsequent study the author explored whether and how brief exposure to a range of concentrations of produced water affected gametes and early larval stages of the purple sea urchin. Specifically, he exposed separately and together, eggs, sperm, and zygotes to ascertain the relative sensitivities of these life stages to produced water at durations and concentrations realistic to each state. He also explored the nature of the biological responses, and the potential for delayed expression. I found that both apparent fertilization and embryonic developmental success showed decreased performance with increasing produced water concentrations. Produced water exposure effectively slowed embryological developmental rates, but did not affect embryo survivorship. The spatial and temporal variability in toxicity of receiving waters was addressed using a fertilization bioassay. Receiving waters were collected along a transect down-field from the discharge on three dates while the outfall was actively discharging, and on one date while the plant was not discharging.

  8. Cloning of a novel phospholipase C-delta isoform from pacific purple sea urchin (Strongylocentrotus purpuratus) gametes and its expression during early embryonic development.

    PubMed

    Coward, Kevin; Owen, Helen; Poustka, Albert J; Hibbitt, Olivia; Tunwell, Richard; Kubota, Hiroki; Swann, Karl; Parrington, John

    2004-01-23

    Calcium (Ca(2+)) is a ubiquitous intracellular messenger, controlling a diverse range of cellular processes, including fertilization and development of the embryo. One of the key mechanisms involved in triggering intracellular calcium release is the generation of the second messenger inositol-1,4,5-phosphate (IP(3)) by the phospholipase C (PLC) class of enzymes. Although five distinct forms of PLC have been identified in mammals (beta, gamma, delta, epsilon, and zeta), only one, PLCgamma, has thus far been detected in echinoderms. In the present study, we describe the isolation of a cDNA encoding a novel PLC isoform of the delta (delta) subclass, PLC-deltasu, from the egg of the Pacific purple sea urchin Strongylocentrotus purpuratus. We also demonstrate the presence of this PLC within the sperm and in the early embryo. The PLC-deltasu cDNA (2.44kb) encodes a 742 amino acid polypeptide with an open reading frame of 84.6kDa and a pI of 6.04. All of the characteristic domains found in mammalian PLCdelta isoforms (PH domain, EF hands, an X-Y catalytic region, and a C2 domain) are present in PLC-deltasu. A homology search revealed that PLC-deltasu shares most sequence identity with bovine PLCdelta2 (39%). We present evidence that PLC-deltasu is expressed in unfertilized eggs, fertilized eggs, and in the early embryo. In addition to Northern and polymerase chain reaction (PCR) analyses, in situ hybridization experiments further demonstrated that the embryonic regions within which the PLC-deltasu transcript can be detected during early embryonic development are associated with the highest levels of proliferative activity, suggesting a possible involvement with metabolism or cell cycle regulation.

  9. Characterization of insulin-like peptides (ILPs) in the sea urchin Strongylocentrotus purpuratus: insights on the evolution of the insulin family.

    PubMed

    Perillo, Margherita; Arnone, Maria Ina

    2014-09-01

    The evolutionary history of the insulin-like peptides (ILPs), members of the insulin family, is still a matter of debate. Although ILPs structure and expression have been described in different metazoans, little is known about these molecules in non-chordate deuterostomes, such as the echinoderms. In order to fill this gap in the current literature, we have characterized two members of the insulin family found in the sea urchin Strongylocentrotus purpuratus genome (SpIgf1 and SpIgf2 that, after our analysis, we suggest to rename SpILP1 and SpILP2, respectively) together with their putative receptor (SpInsr). We found that SpILP1 gene structure is more similar to the cephalochordate amphioxus ILP, while the SpILP2 gene shows a completely different organization. In addition, we have revealed that SpILP1 and SpILP2 transcripts are expressed in different compartments during embryo/larva development and that the SpILP1 protein mature form differs in the egg and the larva, suggesting different biological roles. Finally, we have analyzed SpILP1 transcript and protein expression in response to different feeding regimes through real-time quantitative PCR, Western blot and immunohistochemistry methodologies, and found that its expression and localization are feeding-dependent. We discuss our findings in a comparative evolutionary perspective including data available in other animal models and provide new insights into the evolution of the insulin family molecules. In the model we put forward, the last common ancestor of all deuterostomes presented an ILP composed of the B-C-A-D-E domains, and successive lineage specific independent gene duplication events resulted in the presence of several ILPs in vertebrates and in echinoderms.

  10. Precise cis-regulatory control of spatial and temporal expression of the alx-1 gene in the skeletogenic lineage of s. purpuratus.

    PubMed

    Damle, Sagar; Davidson, Eric H

    2011-09-15

    Deployment of the gene-regulatory network (GRN) responsible for skeletogenesis in the embryo of the sea urchin Strongylocentrotus purpuratus is restricted to the large micromere lineage by a double negative regulatory gate. The gate consists of a GRN subcircuit composed of the pmar1 and hesC genes, which encode repressors and are wired in tandem, plus a set of target regulatory genes under hesC control. The skeletogenic cell state is specified initially by micromere-specific expression of these regulatory genes, viz. alx1, ets1, tbrain and tel, plus the gene encoding the Notch ligand Delta. Here we use a recently developed high throughput methodology for experimental cis-regulatory analysis to elucidate the genomic regulatory system controlling alx1 expression in time and embryonic space. The results entirely confirm the double negative gate control system at the cis-regulatory level, including definition of the functional HesC target sites, and add the crucial new information that the drivers of alx1 expression are initially Ets1, and then Alx1 itself plus Ets1. Cis-regulatory analysis demonstrates that these inputs quantitatively account for the magnitude of alx1 expression. Furthermore, the Alx1 gene product not only performs an auto-regulatory role, promoting a fast rise in alx1 expression, but also, when at high levels, it behaves as an auto-repressor. A synthetic experiment indicates that this behavior is probably due to dimerization. In summary, the results we report provide the sequence level basis for control of alx1 spatial expression by the double negative gate GRN architecture, and explain the rising, then falling temporal expression profile of the alx1 gene in terms of its auto-regulatory genetic wiring.

  11. Development under elevated pCO2 conditions does not affect lipid utilization and protein content in early life-history stages of the purple sea urchin, Strongylocentrotus purpuratus.

    PubMed

    Matson, Paul G; Yu, Pauline C; Sewell, Mary A; Hofmann, Gretchen E

    2012-12-01

    Ocean acidification (OA) is expected to have a major impact on marine species, particularly during early life-history stages. These effects appear to be species-specific and may include reduced survival, altered morphology, and depressed metabolism. However, less information is available regarding the bioenergetics of development under elevated CO(2) conditions. We examined the biochemical and morphological responses of Strongylocentrotus purpuratus during early development under ecologically relevant levels of pCO(2) (365, 1030, and 1450 μatm) that may occur during intense upwelling events. The principal findings of this study were (1) lipid utilization rates and protein content in S. purpuratus did not vary with pCO(2); (2) larval growth was reduced at elevated pCO(2) despite similar rates of energy utilization; and (3) relationships between egg phospholipid content and larval length were found under control but not high pCO(2) conditions. These results suggest that this species may either prioritize endogenous energy toward development and physiological function at the expense of growth, or that reduced larval length may be strictly due to higher costs of growth under OA conditions. This study highlights the need to further expand our knowledge of the physiological mechanisms involved in OA response in order to better understand how present populations may respond to global environmental change.

  12. The genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae: Syllinae) from Australia (second part): four new species and re-description of twelve previously described species.

    PubMed

    Martín, Guillermo San; Álvarez-Campos, Patricia; Hutchings, Pat

    2017-02-27

    Syllis Savigny in Lamarck, 1818, the type genus of Syllidae, is the largest and most diverse within the family. This genus presents many taxonomic and phylogenetic problems due mainly to the lack of molecular data and morphological synapomorphies for many of the species, but also to poor or inadequate descriptions. In order to improve the knowledge of the genus, we have undertaken a morphological revision of Australian species, based on type material and material from the Australian Museum. Sixteen species are herein described, of which four are new and twelve are redescriptions of alreadyknown species, with six new combinations: Syllis boggemanni, n. sp.; S. joaoi, n. sp.; S. karlae, n. sp.; S. marceloi, n. sp.; S. albanyensis (Hartmann-Schröder, 1984) n. comb.; S. erikae (Hartmann-Schröder, 1981) n. comb.; S. krohnii Ehlers 1864; S. lunaris (Imajima, 1966) n. comb.; S. lutea (Hartmann-Schröder, 1960); S. macrodentata (Hartmann-Schröder, 1982) n. comb.; S. monilaris Savigny in Lamarck, 1818; S. nigropunctata Haswell, 1886; S. pectinans Haswell, 1920; S. rosea (Langerhans, 1879); S. warrnamboolensis (Hartmann-Schröder, 1987) n. comb.; and S. yallingupensis (Hartmann-Schröder, 1982), n. comb.

  13. Lamarck Will Not Lie Down.

    ERIC Educational Resources Information Center

    Lewin, Roger

    1981-01-01

    Describes recent research by Edward Steele appearing to support the Lamarckian theory of inheritance. Steele suggests that a mutant somatic cell favored by the environment will undergo clonal expansion. Altered genetic materials from these cells is then picked up by C-type viruses and inserted into the germ line genome. (CS)

  14. Development and validation of a selective and effective pressurized liquid extraction followed by liquid chromatography-mass spectrometry method for the determination of fructosazine analogues in the ammonia treated extract of Eugenia jambolana Lamarck seeds.

    PubMed

    Zhao, Minjie; Arau Jo, Michel Mozeika; Dal, Stéphanie; Sigrist, Séverine; Bergaentzlé, Martine; Ramanitrahasimbola, David; Andrianjara, Charles; Marchioni, Eric

    2016-11-18

    This study describes a selective and effective pressurized liquid extraction (PLE) coupled with HPLC-DAD-ESI/MS method for the identification and quantification of three fructosazine analogues (FZAs), fructosazine, 2,6- and 2,5-deoxyfructosazine in Madeglucyl(®) (MG) which is an ammonia treated extract of Eugenia jambolana Lamarck seeds, and is the world's first anti-diabetic phytodrug. FZAs were extracted from MG by PLE using methanol as extraction solvent. The PLE extract was then analyzed directly by HPLC-DAD-ESI/MS without cleanup step. Chromatographic separation of these highly related structures was achieved on a porous graphic carbon (PGC) column. The identification of the target FZAs was confirmed by the similar retention time, similar UV and MS spectra to the corresponding pure standards. The quantification was performed by using an electrospray positive ionization mass spectrometry in the selected ion monitoring (SIM) mode. The PLE procedure was optimized and overall method was validated in terms of sensitivity, linearity, selectivity and matrix effect, precision, accuracy and recovery, and stability of the target FZAs in the aqueous solution and in the PLE extracts solution of MG. The developed method was proved to be selective, sensitive, precise, accurate for the quantification of FZAs in MG.

  15. Lamarck Is Sitting in the Front Row

    ERIC Educational Resources Information Center

    Crow, Linda

    2004-01-01

    One of the unifying themes of modern biology is evolution. In introductory biology courses, evolution is studied in some detail and used as a focal point for many courses. For many teachers of those courses, the greatest frustration is their inability to help students become Darwinian. Students do not reject evolutionary ideas, but they quickly…

  16. Quantitative developmental transcriptomes of the sea urchin Strongylocentrotus purpuratus

    PubMed Central

    Tu, Qiang; Cameron, R. Andrew; Davidson, Eric H.

    2014-01-01

    Development depends on the precise control of gene expression in time and space. A critical step towards understanding the global gene regulatory networks underlying development is to obtain comprehensive information on gene expression. In this study, we measured expression profiles for the entire expressed gene set during sea urchin embryonic development. We confirmed the reliability of these profiles by comparison with NanoString measurements for a subset of genes and with literature values. The data show that ~16,500 genes have been activated by the end of embryogenesis, and for half of them the transcript abundance changes more than 10-fold during development. From this genome scale expression survey, we show that complex patterns of expression by many genes underlie embryonic development, particularly during the early stages before gastrulation. An intuitive web application for data query and visualization is presented to facilitate use of this large dataset. PMID:24291147

  17. Improving the Geologic Time Scale (Jean Baptiste Lamarck Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Gradstein, Felix M.

    2010-05-01

    The Geologic Time Scale (GTS) provides the framework for the physical, chemical and biological processes on Earth. The time scale is the tool "par excellence" of the geological trade, and insight in its construction, strength, and limitations enhances its function and its utility. Earth scientists should understand how time scales are constructed and its myriad of physical and abstract data are calibrated, rather than merely using ages plucked from a convenient chart or card. Calibration to linear time of the succession of events recorded in the rocks on Earth has three components: (1) the standard stratigraphic divisions and their correlation in the global rock record, (2) the means of measuring linear time or elapsed durations from the rock record, and (3) the methods of effectively joining the two scales, the stratigraphic one and the linear one. Under the auspices of the International Commission on Stratigraphy (ICS), the international stratigraphic divisions and their correlative events are now largely standardized, especially using the GSSP (Global Stratigraphic Section and Point) concept. The means of measuring linear time or elapsed durations from the rock record are objectives in the EARTH TIME and GTS NEXT projects, that also are educating a new generation of GTS dedicated scientists. The U/Pb, Ar/Ar and orbital tuning methods are intercalibrated, and external error analysis improved. Existing Ar/Ar ages become almost 0.5% older, and U/Pb ages stratigraphically more realistic. The new Os/Re method has potential for directly dating more GSSP's and its correlative events. Such may reduce scaling uncertainty between the sedimentary levels of an age date and that of a stage boundary. Since 1981, six successive Phanerozoic GTS have been published, each new one achieving higher resolution and more users. The next GTS is scheduled for 2011/2012, with over 50 specialists taking part. New chapters include an expanded planetary time scale, sequence stratigraphy, Osmium, Carbon and Oxygen stratigraphy, the Cryogenian period, history of the plants, hominid prehistory, and last but not least the Anthropocene. The Cambrian Period is radically improved with 10 standard stages and detailed trilobite biochronology. Ordovician now has a stable international stages and graptolites scale. The integration of a refined 100 and 400 ka sedimentary cycles scale and a truly high-resolution U/Pb ages scale for the Mississippian is a major step towards the global Carboniferous GTS. The Devonian GTS leaves to be desired with lack of firm definitions for its upper boundary, and the long Emsian stage; it also lacks age dates. Its stages scaling is disputed. The Rhaetian and Norian stages in the Triassic and the Berriasian stage in the Cretaceous urgently require lower boundary definitions, and also boundary age dates. The single ~400 ka eccentricity component is very stable and can extend orbital tuning from the Cenozoic well into the Mesozoic portion of the GTS. Jurassic and Cretaceous now have long orbitally tuned segments. A completely astronomical-tuned Geological Time Scale (AGTS) for the Cenozoic is within reach showing unprecedented accuracy, precision and resolution. Burdigalian in the Miocene, and Lutetian, Bartonian and Priabonian stages in the Eocene still require formal definition. The K/T boundary will become about 0.5 ± 0.1 Ma older. After 25 years of research and authorship in the GTS it behoves me to especially thank my colleagues James Ogg, Frits Agterberg, John McArthur and Roger Cooper for longstanding collaboration. As a final note I urge construction of more regional time scales(like developed ‘down under') calibrated to the standard global GTS, to scale regional rock units.

  18. Effects of environmental oxygen deficiency on embryos and larvae of bay scallop, Argopecten irradians irradians

    NASA Astrophysics Data System (ADS)

    Chun-de, Wang; Fu-Sui, Zhang

    1995-12-01

    The experimental results showed that: 1) The embryonic development of bay scallop is inhibited at a dissolved oxygen range of 1.38-3.64×10-3 at 23°C, and completely blocked below the lower limit. 2) The tolerance of larvae to anoxia increased with larval sizes and was related to their oxygen debt. 3) The scallop larvae exhibited specific behavioral responses to oxygen deficiency, which finally led to velum disintegration and larval death. The possible relationship between environmental oxygen deficiency and the disease of disintegration of the larval velum is also discussed. In this study, considerable oxygen debt was found in bay scallop larvae, which was greater in small animals. Based on the works of previous authors, a new concept is proposed for the estimation of oxygen debt, namely, the compensatory rate of oxygen debt (CROD). This can be used in intra—or interspecific comparison of oxygen debt. The results can be helpful in the management of water quality and for the prevention of larval diseases encountered in scallop culture.

  19. Expression of Spgatae, the Strongylocentrotus purpuratus ortholog of vertebrate GATA4/5/6 factors.

    PubMed

    Lee, Pei Yun; Davidson, Eric H

    2004-12-01

    Spgatae is the sea urchin ortholog of the vertebrate gata4/5/6 genes, as confirmed by phylogenetic analysis. The accumulation of Spgatae transcripts during embryonic development and the spatial pattern of expression are reported here. Expression was first detected in the 15 h blastula. The number of Spgatae RNA molecules increases steadily during blastula stages, with expression peaking during gastrulation. After gastrulation is complete, the level of expression decreases until the end of embryogenesis. Whole mount in situ hybridization showed that Spgatae transcripts were first detected in a ring of prospective mesoderm cells in the vegetal plate. Spgatae expression then expands to include the entire vegetal plate at the mesenchyme blastula stage. During gastrulation Spgatae is expressed at the blastopore, and at prism stage strongly in the hindgut and midgut but not foregut, and also in mesoderm cells at the tip of the archenteron. Towards the end of embryogenesis, expression in the hindgut decreases. The terminal pattern of expression is in midgut plus coelomic pouches.

  20. Cellular distribution of okadaic acid in the digestive gland of Mytilus galloprovincialis (Lamarck, 1819).

    PubMed

    Rossignoli, Araceli E; Blanco, Juan

    2008-12-15

    The distribution of okadaic acid between the digestive and the secretory cells of the digestive gland of Mytilus galloprovincialis was studied for the main purpose of determining if they might be responsible for the two-compartment depuration kinetics found in previous studies. The two cell types did not accumulate okadaic acid to the same degree. However, the concentrations found in each cellular type were not consistent with those expected from the output of the two-compartment depuration model, suggesting that a mechanism other that the differential accumulation in cellular types is involved. Binding to some yet undetermined cellular components is suggested.

  1. Metabolomic investigation of Mytilus galloprovincialis (Lamarck 1819) caged in aquatic environments.

    PubMed

    Fasulo, Salvatore; Iacono, Francesco; Cappello, Tiziana; Corsaro, Carmelo; Maisano, Maria; D'Agata, Alessia; Giannetto, Alessia; De Domenico, Elena; Parrino, Vincenzo; Lo Paro, Giuseppe; Mauceri, Angela

    2012-10-01

    Environmental metabolomics was applied to assess the metabolic responses in transplanted mussels to environmental pollution. Specimens of Mytilus galloprovincialis, sedentary filter-feeders, were caged in anthropogenic-impacted and reference sites along the Augusta coastline (Sicily, Italy). Chemical analysis revealed increased levels of PAHs in the digestive gland of mussels from the industrial area compared with control, and marked morphological changes were also observed. Digestive gland metabolic profiles, obtained by 1H NMR spectroscopy and analyzed by multivariate statistics, showed changes in metabolites involved in energy metabolism. Specifically, changes in lactate and acetoacetate could indicate increased anaerobic fermentation and alteration in lipid metabolism, respectively, suggesting that the mussels transplanted to the contaminated field site were suffering from adverse environmental condition. The NMR-based environmental metabolomics applied in this study results thus in it being a useful and effective tool for assessing environmental influences on the health status of aquatic organisms.

  2. Arsenic exposure affects embryo development of sea urchin, Paracentrotus lividus (Lamarck, 1816).

    PubMed

    Gaion, Andrea; Scuderi, Alice; Pellegrini, David; Sartori, Davide

    2013-11-01

    Toxicity tests were performed with embryos of Paracentrotus lividus to investigate the toxicological effect of two arsenic species: arsenate (As(V)), expected to be more toxic, and dimethyl-arsinate (DMA) expected to be less toxic. Exposures to toxicants were performed at different developmental stages in order to identify the most sensitive phase of embryological development. Statistical analysis revealed a high significance of each factor (Molecule, Concentration and Time of exposure) and their interaction for the dependent variable "Percentage of normal-shaped plutei". In particular, the 8 cell stage was the most sensitive to arsenic; at a concentration of 50 μg L(-1) DMA proved to be more toxic than As(V), resulting in nearly 50 % of normal-shaped plutei against the 74 % recorded for As(V). Starting the administration of arsenic at the morula stage, arsenate proved to be significantly more toxic when compared to DMA.

  3. Effects of seawater acidification on early development of the intertidal sea urchin Paracentrotus lividus (Lamarck 1816).

    PubMed

    Moulin, Laure; Catarino, Ana Isabel; Claessens, Thomas; Dubois, Philippe

    2011-01-01

    The effect of pH ranging from 8.0 to 6.8 (total scale - pH(T)) on fertilization, cleavage and larval development until pluteus stage was assessed in an intertidal temperate sea urchin. Gametes were obtained from adults collected in two contrasting tide pools, one showing a significant nocturnal pH decrease (lowest pH(T)=7.4) and another where pH was more stable (lowest pH(T)=7.8). The highest pH(T) at which significant effects on fertilization and cleavage were recorded was 7.6. On the contrary, larval development was only affected below pH(T) 7.4, a value equal or lower than that reported for several subtidal species. This suggests that sea urchins inhabiting stressful intertidal environments produce offspring that may better resist future ocean acidification. Moreover, at pH(T) 7.4, the fertilization rate of gametes whose progenitors came from the tide pool with higher pH decrease was significantly higher, indicating a possible acclimatization or adaptation of gametes to pH stress.

  4. Histopathological effects of contaminated sediments on golden apple snail (Pomacea canaliculata, Lamarck 1822).

    PubMed

    Kruatrachue, M; Sumritdee, C; Pokethitiyook, P; Singhakaew, S

    2011-06-01

    Pomacea canaliculata were exposed experimentally to contaminated sediments from a tributary of the Mae Klong River, Thailand, for 3 months. The highest concentration of Cr, Zn and Fe accumulated in the digestive gland while the gill exhibited the highest concentration of Cu. In addition, histopathological changes (increased mucus vacuoles, loss of cilia, dilation of cells in the epithelial cells of digestive tract organs, and an increase in the number of dark granules in the digestive cells) were observed. The gill exhibited loss of cilia, wider hemolymph space, and degeneration of columnar epithelial cells.

  5. Mitochondrial genome of the Caribbean king crab Damithrax spinosissimus (Lamarck, 1818) (Decapoda: Majidae).

    PubMed

    Márquez, Edna J; Hurtado-Alarcón, Julio C; Isaza, Juan P; Alzate, Juan F; Campos, Néstor H

    2016-05-01

    The Caribbean king crab Damithrax spinosissimus (former Mithrax spinosissimus) is a large brachyuran in the tropical and subtropical western Atlantic. This is the first report of the complete mitochondrial genome of D. spinosissimus, which was pyrosequenced by FLX 454 technology. The mtDNA encodes for 13 proteins, 22 tRNAs and 2 ribosomal RNAs. In addition, the coding sequences and gene synteny were similar to other previously reported mitogenomes of brachyuran.

  6. Scale-invariance of sediment patterns - the fingerprint of fundamental drivers (Jean Baptiste Lamarck Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Schlager, Wolfgang

    2015-04-01

    In contrast to the realms of magmatism and metamorphism, most depositional processes can be observed directly at the earth's surface. Observation of sediment patterns advanced significantly with the advent of remote sensing and 3D reflection seismics. Remote sensing is particularly relevant for the present topic because it documents mainly Holocene sediments - the best objects to link depositional processes to products. Classic examples of scale-invariant geometry are channel-fan systems, i.e. river-delta and canyon-fan complexes. The underlying control in both instances is the energy-dispersion of a channeled stream of water that discharges in a body of still water. The resulting fan-shaped sediment accumulations are scale-invariant over 7 orders of magnitude in linear size. The Mesozoic-Cenozoic record shows comparable trends and patterns. Further examples of depositional scale-invariance include foresets of non-cohesive sediments and braided-channel deposits. Reefs and carbonate platforms offer an example of scale-invariance related to biotic growth. Shallow-water carbonate platforms rimmed by reefs or reef-rimmed atolls with deep lagoons are characteristic morphologies of tropical carbonate deposits. The structure has been compared to a bucket where stiff reef rims hold a pile of loose sediment. Remote sensing data from the Maldive, Chagos and Laccadive archipelagos of the Indian Ocean show that bucket structures are the dominant depositional pattern from meter-size reefs to archipelagos of hundreds of kilometers in diameter, i.e. over more than 4 orders of magnitude in linear size. Over 2.5 orders of magnitude, the bucket structures qualify as statistical fractals. Ecologic and hydrodynamic studies on modern reefs suggest that the bucket structure is a form of biotic self-organization: The edge position in a reef is favored over the center position because bottom shear is higher and the diffusive boundary layer between reef and water thinner. Thus, the reef edge has easier access to nutrients. Moreover, the edge is less likely to be buried by sediment. The bucket structure is an ecologic response to these conditions. Buckets have been documented from all periods of the Phanerozoic and analogous structures from the late Proterozoic show that the microbial carbonate factory also built buckets. We conclude that a voyage through scales in the sediment realm reveals islands of scale-invariance wherever a single principle dominates the sedimentation process.

  7. "Days of future passed" - climate change and carbon cycle history (Jean Baptiste Lamarck Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Weissert, Helmut

    2013-04-01

    With the beginning of the fossil fuel age in the 19th century mankind has become an important geological agent on a global scale. For the first time in human history action of man has an impact on global biogeochemical cycles. Increasing CO2 concentrations will result in a perturbation of global carbon cycling coupled with climate change. Investigations of past changes in carbon cycling and in climate will improve our predictions of future climate. Increasing atmospheric CO2 concentrations will drive climate into a mode of operation, which may resemble climate conditions in the deep geological past. Pliocene climate will give insight into 400ppm world with higher global sea level than today. Doubling of pre-industrial atmospheric CO2 levels will shift the climate system into a state resembling greenhouse climate in the Early Cenozoic or even in the Cretaceous. Carbon isotope geochemistry serves as tool for tracing the pathway of the carbon cycle through geological time. Globally registered negative C-isotope anomalies in the C-isotope record are interpreted as signatures of rapid addition (103 to a few 104 years) of CO2 to the ocean-atmosphere system. Positive C-isotope excursions following negative spikes record the slow post-perturbation recovery of the biosphere at time scales of 105 to 106 years. Duration of C-cycle perturbations in earth history cannot be directly compared with rapid perturbation characterizing the Anthropocene. However, the investigation of greenhouse pulses in the geological past provides insight into different climate states, it allows to identify tipping points in past climate systems and it offers the opportunity to learn about response reactions of the biosphere to rapid changes in global carbon cycling. Sudden injection of massive amounts of carbon dioxide into the atmosphere is recorded in C-isotope record of the Early Cretaceous. The Aptian carbon cycle perturbation triggered changes in temperature and in global hydrological cycling. Changes in physical and chemical oceanography are reflected in widespread black shale deposition ("Oceanic Anoxic Event 1a"), in carbonate platform drowning and in biocalcification crises. "Days of future passed" (Moody Blues, 1967) reminds us that the past provides essential information needed for decisions to be made in the interest of mankind's future.

  8. The first troglomorphic species of the genus Phrynus Lamarck, 1801 (Amblypygi: Phrynidae) from Mexico.

    PubMed

    Guzmán, Ali Abadallan; Joya, Daniel Chirivi; Francke, Oscar F

    2015-02-23

    A new troglomorphic species, Phrynus perrii sp. nov., is described from two adult females from Cueva del Naranjo, Municipio Cintalapa, Chiapas, Mexico. This is the first continental record of a troglomorphic Phrynus species, and the second troglomorphic species of the genus. With the description of this species, in Mexico there are ten extant species, plus one fossil of the genus Phrynus, and it is the seventh species of troglobitic whip spiders from Mexico, making it the country with the highest richness of amblypygids species worldwide.

  9. Lamarck rises from his grave: parental environment-induced epigenetic inheritance in model organisms and humans.

    PubMed

    Wang, Yan; Liu, Huijie; Sun, Zhongsheng

    2017-02-20

    Organisms can change their physiological/behavioural traits to adapt and survive in changed environments. However, whether these acquired traits can be inherited across generations through non-genetic alterations has been a topic of debate for over a century. Emerging evidence indicates that both ancestral and parental experiences, including nutrition, environmental toxins, nurturing behaviour, and social stress, can have powerful effects on the physiological, metabolic and cellular functions in an organism. In certain circumstances, these effects can be transmitted across several generations through epigenetic (i.e. non-DNA sequence-based rather than mutational) modifications. In this review, we summarize recent evidence on epigenetic inheritance from parental environment-induced developmental and physiological alterations in nematodes, fruit flies, zebrafish, rodents, and humans. The epigenetic modifications demonstrated to be both susceptible to modulation by environmental cues and heritable, including DNA methylation, histone modification, and small non-coding RNAs, are also summarized. We particularly focus on evidence that parental environment-induced epigenetic alterations are transmitted through both the maternal and paternal germlines and exert sex-specific effects. The thought-provoking data presented here raise fundamental questions about the mechanisms responsible for these phenomena. In particular, the means that define the specificity of the response to parental experience in the gamete epigenome and that direct the establishment of the specific epigenetic change in the developing embryos, as well as in specific tissues in the descendants, remain obscure and require elucidation. More precise epigenetic assessment at both the genome-wide level and single-cell resolution as well as strategies for breeding at relatively sensitive periods of development and manipulation aimed at specific epigenetic modification are imperative for identifying parental environment-induced epigenetic marks across generations. Considering their diverse epigenetic architectures, the conservation and prevalence of the mechanisms underlying epigenetic inheritance in non-mammals require further investigation in mammals. Interpretation of the consequences arising from epigenetic inheritance on organisms and a better understanding of the underlying mechanisms will provide insight into how gene-environment interactions shape developmental processes and physiological functions, which in turn may have wide-ranging implications for human health, and understanding biological adaptation and evolution.

  10. Early detection of potentially invasive invertebrate species in Mytilus galloprovincialis Lamarck, 1819 dominated communities in harbours

    NASA Astrophysics Data System (ADS)

    Preda, Cristina; Memedemin, Daniyar; Skolka, Marius; Cogălniceanu, Dan

    2012-12-01

    Constanţa harbour is a major port on the western coast of the semi-enclosed Black Sea. Its brackish waters and low species richness make it vulnerable to invasions. The intensive maritime traffic through Constanţa harbour facilitates the arrival of alien species. We investigated the species composition of the mussel beds on vertical artificial concrete substrate inside the harbour. We selected this habitat for study because it is frequently affected by fluctuating levels of temperature, salinity and dissolved oxygen, and by accidental pollution episodes. The shallow communities inhabiting it are thus unstable and often restructured, prone to accept alien species. Monthly samples were collected from three locations from the upper layer of hard artificial substrata (maximum depth 2 m) during two consecutive years. Ten alien macro-invertebrate species were inventoried, representing 13.5% of the total number of species. Two of these alien species were sampled starting the end of summer 2010, following a period of high temperatures that triggered hypoxia, causing mass mortalities of benthic organisms. Based on the species accumulation curve, we estimated that we have detected all benthic alien species on artificial substrate from Constanţa harbour, but additional effort is required to detect all the native species. Our results suggest that monitoring of benthic communities at small depths in harbours is a simple and useful tool in early detection of potentially invasive alien species. The selected habitat is easily accessible, the method is low-cost, and the samples represent reliable indicators of alien species establishment.

  11. Bioconversion of (13)C-labeled microalgal phytosterols to cholesterol by the Northern Bay scallop, Argopecten irradians irradians.

    PubMed

    Giner, José-Luis; Zhao, Hui; Dixon, Mark S; Wikfors, Gary H

    2016-02-01

    Bivalve mollusks lack de novo cholesterol biosynthesis capabilities and therefore rely upon dietary sources of sterols for rapid growth. Microalgae that constitute the main source of nutrition for suspension-feeding bivalves contain a diverse array of phytosterols, in most cases lacking cholesterol. Rapid growth of bivalves on microalgal diets with no cholesterol implies that some phytosterols can satisfy the dietary requirement for cholesterol through metabolic conversion to cholesterol, but such metabolic pathways have not been rigorously demonstrated. In the present study, stable isotope-labeled phytosterols were used to supplement a unialgal diet of Rhodomonas sp. and their biological transformation to cholesterol within scallop tissues was determined using (13)C-NMR spectroscopy. Scallops efficiently dealkylated ∆(5) C29 (24-ethyl) sterols to cholesterol, and the only C28 sterol that was dealkylated efficiently possessed the 24(28)-double bond. Non-metabolized dietary phytosterols accumulated in the soft tissues. Observed formation of ∆(5,7) sterols (provitamin D) from ∆(5) sterols may represent initiation of steroid hormone (possibly ecdysone) biosynthesis. These findings provide a key component necessary for formulation of nutritionally complete microalgal diets for hatchery production of seed for molluscan aquaculture.

  12. Growth and Development of Larval Bay Scallops (Argopecten irradians) in Response to Early Exposure to High CO2

    DTIC Science & Technology

    2013-02-01

    S .  Peck.  2009.  Early  larval   development  of  the  Sydney...Kurihara,  H.,   S .  Kato,  and  A.  Ishimatsu.  2007.  Effects  of  increased  seawater  pCO2  on   early   development ...and  L.   S .  Peck.  2009.  Early  larval   development  of  the  Sydney  rock  oyster  Saccostrea  glomerata

  13. Changes in trophic flow structure of Independence Bay (Peru) over an ENSO cycle

    NASA Astrophysics Data System (ADS)

    Taylor, Marc H.; Wolff, Matthias; Mendo, Jaime; Yamashiro, Carmen

    2008-10-01

    During the strong warm El Niño (EN) that occurred in 1997/98, Independence Bay (14°S, Peru) showed a ca. 10 °C increase in surface temperatures, higher oxygen concentrations, and clearer water due to decreased phytoplankton concentrations. Under these quasi-tropical conditions, many benthic species suffered (e.g. macroalgae, portunid crabs, and polychaetes) while others benefited (e.g. scallop, sea stars, and sea urchins). The most obvious change was the strong recruitment success and subsequent proliferation of the scallop Argopecten purpuratus, whose biomass increased fiftyfold. To understand these changes, steady-state models of the bay ecosystem trophic structure were constructed and compared for a normal upwelling year (1996) and during an EN (1998), and longer-term dynamics (1996-2003) were explored based on time series of catch and biomass using Ecopath with Ecosim (EwE) software. Model inputs were based on surveys and landings data collected by the Instituto del Mar del Perú (IMARPE). Results indicate that while ecosystem size (total throughput) is reduced by 18% during EN, mainly as a result of decreased total primary production, benthic biomass remains largely unchanged despite considerable shifts in the dominant benthic taxa (e.g. scallops replace polychaetes as secondary consumers). Under normal upwelling conditions, predation by snails and crabs utilize the production of their prey almost completely, resulting in more efficient energy flow to higher trophic levels than occurs during EN. However during EN, the proliferation of the scallop A. purpuratus combined with decreased phytoplankton increased the proportion of directly utilized primary production, while exports and flows to detritus are reduced. The simulations suggest that the main cause for the scallop outburst and for the reduction in crab and macroalgae biomass was a direct temperature effect, whereas other changes are partially explained by trophic interactions. The simulations suggest

  14. Permanent genetic resources added to Molecular Ecology Resources Database 1 August 2011-30 September 2011.

    PubMed

    A'Hara, S W; Amouroux, P; Argo, Emily E; Avand-Faghih, A; Barat, Ashoktaru; Barbieri, Luiz; Bert, Theresa M; Blatrix, R; Blin, Aurélie; Bouktila, D; Broome, A; Burban, C; Capdevielle-Dulac, C; Casse, N; Chandra, Suresh; Cho, Kyung Jin; Cottrell, J E; Crawford, Charles R; Davis, Michelle C; Delatte, H; Desneux, Nicolas; Djieto-Lordon, C; Dubois, M P; El-Mergawy, R A A M; Gallardo-Escárate, C; Garcia, M; Gardiner, Mary M; Guillemaud, Thomas; Haye, P A; Hellemans, B; Hinrichsen, P; Jeon, Ji Hyun; Kerdelhué, C; Kharrat, I; Kim, Ki Hwan; Kim, Yong Yul; Kwan, Ye-Seul; Labbe, Ellen M; LaHood, Eric; Lee, Kyung Mi; Lee, Wan-Ok; Lee, Yat-Hung; Legoff, Isabelle; Li, H; Lin, Chung-Ping; Liu, S S; Liu, Y G; Long, D; Maes, G E; Magnoux, E; Mahanta, Prabin Chandra; Makni, H; Makni, M; Malausa, Thibaut; Matura, Rakesh; McKey, D; McMillen-Jackson, Anne L; Méndez, M A; Mezghani-Khemakhem, M; Michel, Andy P; Paul, Moran; Muriel-Cunha, Janice; Nibouche, S; Normand, F; Palkovacs, Eric P; Pande, Veena; Parmentier, K; Peccoud, J; Piatscheck, F; Puchulutegui, Cecilia; Ramos, R; Ravest, G; Richner, Heinz; Robbens, J; Rochat, D; Rousselet, J; Saladin, Verena; Sauve, M; Schlei, Ora; Schultz, Thomas F; Scobie, A R; Segovia, N I; Seyoum, Seifu; Silvain, J-F; Tabone, Elisabeth; Van Houdt, J K J; Vandamme, S G; Volckaert, F A M; Wenburg, John; Willis, Theodore V; Won, Yong-Jin; Ye, N H; Zhang, W; Zhang, Y X

    2012-01-01

    This article documents the addition of 299 microsatellite marker loci and nine pairs of single-nucleotide polymorphism (SNP) EPIC primers to the Molecular Ecology Resources (MER) Database. Loci were developed for the following species: Alosa pseudoharengus, Alosa aestivalis, Aphis spiraecola, Argopecten purpuratus, Coreoleuciscus splendidus, Garra gotyla, Hippodamia convergens, Linnaea borealis, Menippe mercenaria, Menippe adina, Parus major, Pinus densiflora, Portunus trituberculatus, Procontarinia mangiferae, Rhynchophorus ferrugineus, Schizothorax richardsonii, Scophthalmus rhombus, Tetraponera aethiops, Thaumetopoea pityocampa, Tuta absoluta and Ugni molinae. These loci were cross-tested on the following species: Barilius bendelisis, Chiromantes haematocheir, Eriocheir sinensis, Eucalyptus camaldulensis, Eucalyptus cladocalix, Eucalyptus globulus, Garra litaninsis vishwanath, Garra para lissorhynchus, Guindilla trinervis, Hemigrapsus sanguineus, Luma chequen. Guayaba, Myrceugenia colchagüensis, Myrceugenia correifolia, Myrceugenia exsucca, Parasesarma plicatum, Parus major, Portunus pelagicus, Psidium guayaba, Schizothorax richardsonii, Scophthalmus maximus, Tetraponera latifrons, Thaumetopoea bonjeani, Thaumetopoea ispartensis, Thaumetopoea libanotica, Thaumetopoea pinivora, Thaumetopoea pityocampa ena clade, Thaumetopoea solitaria, Thaumetopoea wilkinsoni and Tor putitora. This article also documents the addition of nine EPIC primer pairs for Euphaea decorata, Euphaea formosa, Euphaea ornata and Euphaea yayeyamana.

  15. Induction of DNA-protein cross-links in developing embryos of the purple sea urchin, Strongylocentrotus purpuratus

    SciTech Connect

    Garman, G.D.; Cherr, G.N.; Anderson, S.L.

    1994-12-31

    Exposure to environmental agents during embryonic development may result in DNA-protein cross-linking (DPC), as has been demonstrated for mammalian cell lines. In the latter, formation of DPC`s upon exposure to a wide variety of agents, including some metals, has been observed. To determine whether DPCs could be detected in the sea urchin embryo during development, the authors adapted a mammalian cell assay utilizing potassium-SDS precipitation and a DNA fluorochrome to quantify relative amounts of free and protein-bound DNA. Sea urchin embryos exposed to a known DPC agent, nickel, through gastrulation exhibited a dose-dependent increase in DPCs, as well as an increase in developmental abnormalities. Morphological studies demonstrated that stage-specific exposure to Ni prior to gastrulation resulted in similar levels of abnormal pluteus larval development as compared to embryos exposed through gastrulation. Sea urchin embryos exhibit temporal differences in DNA transcription and gene expression during development, and these could be affected by modifications in DNA-protein interactions. Therefore, the authors are investigating the hypothesis that the similarities in morphological responses observed may relate to susceptibility of a critical stage of development.

  16. Characterization of a homolog of human bone morphogenetic protein 1 in the embryo of the sea urchin, Strongylocentrotus purpuratus.

    PubMed

    Hwang, S P; Partin, J S; Lennarz, W J

    1994-03-01

    A cDNA clone encoding a protein homologous to human bone morphogenetic protein 1 (huBMP1) was isolated from a sea urchin embryo cDNA library. This sea urchin gene, named suBMP, encodes a protein of M(r) of 72 x 10(3). The deduced amino acid sequence of suBMP shares 72% sequence similarity (55% identity) with that of huBMP1. Like huBMP1 it also contains an N-terminal metalloendoprotease domain that shares sequence similarity with the astacin protease from crayfish, a C-terminal domain that is similar to the repeat domain found in C1r or C1s serine proteases, and an EGF-like segment. Although suBMP mRNA was detectable at a low level in the unfertilized egg, maximal expression of mRNA was observed at hatched blastula stage, with only a modest decrease in level at later stages of development. In situ hybridization studies revealed that suBMP mRNA is found in both ectodermal and primary mesenchyme cells in hatched blastula-stage embryos. Maximal expression of suBMP was observed at mesenchyme blastula, just before the onset of primitive skeleton (spicule) formation. SuBMP was found by immunoelectronmicroscopy in all cell types in late gastrula stage embryos. The antibody gold particles appeared in small clusters in the cytoplasm, on the surface of the cells and within the blastocoel. This distribution of suBMP, coupled with the finding that it was associated with membranes but was released by sodium carbonate treatment, suggests that the protein is secreted, and subsequently associates with a cell surface component. Two models for the possible function of suBMP in spiculogenesis in the sea urchin embryo are discussed.

  17. Identification of kinesin-C, a calmodulin-binding carboxy-terminal kinesin in animal (Strongylocentrotus purpuratus) cells.

    PubMed

    Rogers, G C; Hart, C L; Wedaman, K P; Scholey, J M

    1999-11-19

    Several novel members of the kinesin superfamily, until now identified only in plants, are unique in their ability to bind calmodulin in the presence of Ca(2+). Here, we identify the first such kinesin in an animal system. Sequence analysis of this new motor, called kinesin-C, predicts that it is a large carboxy-terminal kinesin, 1624 amino acid residues in length, with a predicted molecular mass of 181 kDa. Kinesin-C is predicted to contain a kinesin motor domain at its carboxy terminus, linked to a segment of alpha-helical coiled-coil 950 amino acid residues long, ending with an amino-terminal proline-rich tail domain. A putative calmodulin-binding domain resides at the extreme carboxy terminus of the motor polypeptide, and recombinant kinesin-C binds to a calmodulin-affinity column in a Ca(2+)-dependent fashion. The presence of this novel calmodulin-binding motor in sea urchin embryos suggests that it plays a critical role in Ca(2+)-dependent events during early sea urchin development.

  18. Ionic status, calcium uptake, and Ca2+-ATPase activity during early development in the purple sea urchin (Strongylocentrotus purpuratus).

    PubMed

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

    2013-10-01

    Ionic status during early development was investigated in the purple sea urchin. Whole body cation concentrations (Ca(2+), Na(+), K(+), Mg(2+)), unidirectional Ca(2+) uptake rates measured with (45)Ca(2+), Ca(2+)-ATPase activity, and growth were examined at 12h intervals over the first 96h of development. Whole body Ca(2+) concentration was low initially but increased steadily by >15-fold through to the pluteus stage. Whole body Mg(2+), K(+) and Na(+) levels exhibited diverse patterns, but all increased at 72-96h. Ca(2+) uptake rates were low during initial cell cleavages at 12h but increased greatly at blastulation (24h) and then again at gastrulation (48h), declining thereafter in the pluteus stage, but increasing slightly at 96h. Ca(2+)-ATPase activity was initially low but increased at blastulation through gastrulation (24-48h) but declined thereafter in the pluteus stage. Embryonic weights did not change over most of development, but were significantly higher at 96h. Overall, the gastrulation stage displayed the most pronounced changes, as Ca(2+) uptake and accumulation and Ca(2+)-ATPase levels were the highest at this stage, likely involved in mineralization of the spicule. Biomarkers of Ca(2+) metabolism may be good endpoints for potential future toxicity studies.

  19. Sublethal mechanisms of Pb and Zn toxicity to the purple sea urchin (Strongylocentrotus purpuratus) during early development.

    PubMed

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

    2014-01-01

    In order to understand sublethal mechanisms of lead (Pb) and zinc (Zn) toxicity, developing sea urchins were exposed continuously from 3h post-fertilization (eggs) to 96 h (pluteus larvae) to 55 (±2.4) μgPb/L or 117 (±11)μgZn/L, representing ~ 70% of the EC50 for normal 72 h development. Growth, unidirectional Ca uptake rates, whole body ion concentrations (Na, K, Ca, Mg), Ca(2+) ATPase activity, and metal bioaccumulation were monitored every 12h over this period. Pb exhibited marked bioaccumulation whereas Zn was well-regulated, and both metals had little effect on growth, measured as larval dry weight, or on Na, K, or Mg concentrations. Unidirectional Ca uptake rates (measured by (45)Ca incorporation) were severely inhibited by both metals, resulting in lower levels of whole body Ca accumulation. The greatest disruption occurred at gastrulation. Ca(2+) ATPase activity was also significantly inhibited by Zn but not by Pb. Interestingly, embryos exposed to Pb showed some capacity for recovery, as Ca(2+)ATPase activities increased, Ca uptake rates returned to normal intermittently, and whole body Ca levels were restored to control values by 72-96 h of development. This did not occur with Zn exposure. Both Pb and Zn rendered their toxic effects through disruption of Ca homeostasis, though likely through different proximate mechanisms. We recommend studying the toxicity of these contaminants periodically throughout development as an effective way to detect sublethal effects, which may not be displayed at the traditional toxicity test endpoint of 72 h.

  20. Sensitivity towards elevated pCO2 in great scallop (Pecten maximus Lamarck) embryos and fed larvae

    NASA Astrophysics Data System (ADS)

    Andersen, Sissel; Grefsrud, Ellen S.; Harboe, Torstein

    2017-02-01

    The increasing amount of dissolved anthropogenic CO2 has caused a drop in pH values in the open ocean known as ocean acidification. This change in seawater carbonate chemistry has been shown to have a negative effect on a number of marine organisms. Early life stages are the most vulnerable, and especially the organisms that produce calcified structures in the phylum Mollusca. Few studies have looked at effects on scallops, and this is the first study presented including fed larvae of the great scallop (Pecten maximus) followed until day 14 post-fertilization. Fertilized eggs from unexposed parents were exposed to three levels of pCO2 using four replicate units: 465 (ambient), 768 and 1294 µatm, corresponding to pHNIST of 7.94, 7.75 (-0.19 units) and 7.54 (-0.40 units), respectively. All of the observed parameters were negatively affected by elevated pCO2: survival, larval development, shell growth and normal shell development. The latter was observed to be affected only 2 days after fertilization. Negative effects on the fed larvae at day 7 were similar to what was shown earlier for unfed P. maximus larvae. Growth rate in the group at 768 µatm seemed to decline after day 7, indicating that the ability to overcome the environmental change at moderately elevated pCO2 was lost over time. The present study shows that food availability does not decrease the sensitivity to elevated pCO2 in P. maximus larvae. Unless genetic adaptation and acclimatization counteract the negative effects of long term elevated pCO2, recruitment in populations of P. maximus will most likely be negatively affected by the projected drop of 0.06-0.32 units in pH within year 2100.

  1. Bleaching increases likelihood of disease on Acropora palmata (Lamarck) in Hawksnest Bay, St John, US Virgin Islands

    USGS Publications Warehouse

    Muller, E.M.; Rogers, Caroline S.; Spitzack, Anthony S.; van Woesik, R.

    2007-01-01

    Anomalously high water temperatures may enhance the likelihood of coral disease outbreaks by increasing the abundance or virulence of pathogens, or by increasing host susceptibility. This study tested the compromised-host hypothesis, and documented the relationship between disease and temperature, through monthly monitoring of Acropora palmata colonies from May 2004 to December 2006, in Hawksnest Bay, St John, US Virgin Islands (USVI). Disease prevalence and the rate of change in prevalence showed a positive linear relationship with water temperature and rate of change in water temperature, respectively, but only in 2005 during prolonged periods of elevated temperature. Both bleached and unbleached colonies showed a positive relationship between disease prevalence and temperature in 2005, but the average area of disease-associated mortality increased only for bleached corals, indicating host susceptibility, rather than temperature per se, influenced disease severity on A. palmata.

  2. Bleaching increases likelihood of disease on Acropora palmata (Lamarck) in Hawksnest Bay, St John, US Virgin Islands

    USGS Publications Warehouse

    Muller, E.M.; Rogers, C.S.; Spitzack, Anthony S.; van Woesik, R.

    2008-01-01

    Anomalously high water temperatures may enhance the likelihood of coral disease outbreaks by increasing the abundance or virulence of pathogens, or by increasing host susceptibility. This study tested the compromised-host hypothesis, and documented the relationship between disease and temperature, through monthly monitoring of Acropora palmata colonies from May 2004 to December 2006, in Hawksnest Bay, St John, US Virgin Islands (USVI). Disease prevalence and the rate of change in prevalence showed a positive linear relationship with water temperature and rate of change in water temperature, respectively, but only in 2005 during prolonged periods of elevated temperature. Both bleached and unbleached colonies showed a positive relationship between disease prevalence and temperature in 2005, but the average area of disease-associated mortality increased only for bleached corals, indicating host susceptibility, rather than temperature per se, influenced disease severity on A. palmata. ?? 2007 Springer-Verlag.

  3. Epigenetics as a source of variation in comparative animal physiology - or - Lamarck is lookin' pretty good these days.

    PubMed

    Burggren, Warren W

    2014-03-01

    Considerable variation is inherent both within and between comparative physiological data sets. Known sources for such variation include diet, gender, time of day and season of experiment, among many other factors, but a meta-analysis of physiological studies shows that surprisingly few studies report controlling for these factors. In fact, less than 3% of comparative physiological papers mention epigenetics. However, our understanding of epigenetic influences on physiological processes is growing rapidly, and it is highly likely that epigenetic phenomena are an additional 'hidden' source of variation, particularly in wild-caught specimens. Recent studies have shown epigenetic inheritance of commonly studied traits such as metabolic rate (water fleas Daphnia magna; emu, Dromaius novaellandiae), hypoxic tolerance, cardiac performance (zebrafish, Danio rerio), as well as numerous morphological effects. The ecological and evolutionary significance of such epigenetic inheritance is discussed in a comparative physiological context. Finally, against this context of epigenetic inheritance of phenotype, this essay also provides a number of caveats and warnings regarding the interpretation of transgenerational phenotype modification as a true epigenetic phenomenon. Parental effects, sperm storage, multiple paternity and direct gamete exposure can all be confounding factors. Epigenetic inheritance may best be studied in animal models that can be maintained in the laboratory over multiple generations, to yield parental stock that themselves are free of epigenetic effects from the historical experiences of their parents.

  4. Trawling disturbance on the isotopic signature of a structure-building species, the sea urchin Gracilechinus acutus (Lamarck, 1816)

    NASA Astrophysics Data System (ADS)

    González-Irusta, José M.; Preciado, Izaskun; López-López, Lucia; Punzón, Antonio; Cartes, Joan E.; Serrano, Alberto

    2014-08-01

    Bottom trawling is one of the main sources of anthropogenic disturbance in benthic habitats with important direct and indirect effects on the ecosystem functional diversity. In this study, the effect of this impact on a structure-building species, the sea urchin Gracilechinus acutus, was studied in the Central Cantabrian Sea (southern Bay of Biscay) comparing its isotopic signature and additional population descriptors across different trawling pressures. Trawling disturbance had a significant effect on the studied descriptors. In trawling areas, this urchin showed significantly lower values of biomass and mean size and significantly higher values of fullness index. Moreover, the trawling disturbance effect was also significant in the isotopic signature of G. acutus. Urchins inhabiting untrawled areas showed significant lower values of δ15N than urchins dwelling areas under trawling pressure. The urchins' isotopic enrichment increased along the species ontogeny regardless of the trawling effort level. Stable isotope analyses are a suitable tool to detect trawling disturbance on the trophic pathways but do not suffice to explain these changes, especially if there is a lack of baseline information.

  5. Reevaluating species number, distribution and endemism of the coral genus Pocillopora Lamarck, 1816 using species delimitation methods and microsatellites.

    PubMed

    Gélin, P; Postaire, B; Fauvelot, C; Magalon, H

    2017-04-01

    Species delimitation methods based on genetic information, notably using single locus data, have been proposed as means of increasing the rate of biodiversity description, but can also be used to clarify complex taxonomies. In this study, we explore the species diversity within the cnidarian genus Pocillopora, widely distributed in the tropical belt of the Indo-Pacific Ocean. From 943 Pocillopora colonies sampled in the Western Indian Ocean, the Tropical Southwestern Pacific and Southeast Polynesia, representing a huge variety of morphotypes, we delineated Primary Species Hypotheses (PSH) applying the Automatic Barcode Gap Discovery method, the Poisson Tree Processes algorithm and the Generalized mixed Yule-coalescent model on two mitochondrial markers (Open Reading Frame and Dloop) and reconstructing a haploweb using one nuclear marker (Internal Transcribed Spacer 2). Then, we confronted identified PSHs to the results of clustering analyses using 13 microsatellites to determine Secondary Species Hypotheses (SSH). Based on the congruence of all methods used and adding sequences from the literature, we defined at least 18 Secondary Species Hypotheses among 14 morphotypes, confirming the high phenotypic plasticity in Pocillopora species and the presence of cryptic lineages. We also identified three new genetic lineages never found to date, which could represent three new putative species. Moreover, the biogeographical ranges of several SSHs were re-assessed in the light of genetic data, which may have direct implications in conservation policies. Indeed, the cryptic diversity within this genus should be taken into account seriously, as neglecting its importance is source of confusion in our understanding of ecosystem functioning. Next generation sequencing, combined with other parameters (i.e. microstructure, zooxanthellae identification, ecology even at a micro-scale, resistance and resilience ability to bleaching) will be the next step towards an integrative framework of Pocillopora taxonomy, which will have profound implications for ecological studies, such as studying biodiversity, response to global warming and symbiosis.

  6. Molecular phylogeny of Pholadoidea Lamarck, 1809 supports a single origin for xylotrophy (wood feeding) and xylotrophic bacterial endosymbiosis in Bivalvia.

    PubMed

    Distel, Daniel L; Amin, Mehwish; Burgoyne, Adam; Linton, Eric; Mamangkey, Gustaf; Morrill, Wendy; Nove, John; Wood, Nicole; Yang, Joyce

    2011-11-01

    The ability to consume wood as food (xylotrophy) is unusual among animals. In terrestrial environments, termites and other xylotrophic insects are the principle wood consumers while in marine environments wood-boring bivalves fulfill this role. However, the evolutionary origin of wood feeding in bivalves has remained largely unexplored. Here we provide data indicating that xylotrophy has arisen just once in Bivalvia in a single wood-feeding bivalve lineage that subsequently diversified into distinct shallow- and deep-water branches, both of which have been broadly successful in colonizing the world's oceans. These data also suggest that the appearance of this remarkable life habit was approximately coincident with the acquisition of bacterial endosymbionts. Here we generate a robust phylogeny for xylotrophic bivalves and related species based on sequences of small and large subunit nuclear rRNA genes. We then trace the distribution among the modern taxa of morphological characters and character states associated with xylotrophy and xylotrepesis (wood-boring) and use a parsimony-based method to infer their ancestral states. Based on these ancestral state reconstructions we propose a set of plausible hypotheses describing the evolution of symbiotic xylotrophy in Bivalvia. Within this context, we reinterpret one of the most remarkable progressions in bivalve evolution, the transformation of the "typical" myoid body plan to create a unique lineage of worm-like, tube-forming, wood-feeding clams. The well-supported phylogeny presented here is inconsistent with most taxonomic treatments for xylotrophic bivalves, indicating that the bivalve family Pholadidae and the subfamilies Teredininae and Bankiinae of the family Teredinidae are non-monophyletic, and that the principle traits used for their taxonomic diagnosis are phylogenetically misleading.

  7. T-PAH contamination in Mediterranean mussels (Mytilus galloprovincialis, Lamarck, 1819) at various stations of the Turkish Straits System.

    PubMed

    Balcıoğlu, Esra Billur; Aksu, Abdullah; Balkıs, Nuray; Öztürk, Bayram

    2014-11-15

    Mussels (Mytilus galloprovincialis) from the Turkish Straits Systems were analyzed for sixteen parent polycyclic aromatic hydrocarbon (PAH) contents by high performance liquid chromatography (HPLC). This marine organism was selected because of its multitude, wide distribution, being bio indicator for the pollution and consumption by humans. Total PAH concentrations ranged from 1.2 to 589 μg g(-1) in Istanbul Strait, 0.94-36.4 μg g(-1) in Marmara Sea and 0.4-47.9 μg g(-1) in Çanakkale Strait during the samplings. According to the results Istanbul and Çanakkale Straits are more polluted than the Marmara Sea.

  8. Larval settlement and spat recovery rates of the oyster Crassostrea brasiliana (Lamarck, 1819) using different systems to induce metamorphosis.

    PubMed

    Silveira, R C; Silva, F C; Gomes, C H M; Ferreira, J F; Melo, C M R

    2011-05-01

    This study aimed at the assessment, in the laboratory, of the larval settlement and spat recovery rates of oysters of the species Crassostrea brasiliana using plastic collectors, epinephrine (C9H13NO3 C4H6O6) and shell powder in settlement tanks. Polypropylene was used attached to bamboo frames. The material was chosen due to its pliability--that favours the spat detachment. Two experiments were carried out; the first between February and April 2008, and the second between November and December 2008 at the Marine Mussel Laboratory of Santa Catarina Federal University (Laboratório de Moluscos Marinhos da Universidade Federal de Santa Catarina). In the first experiment, the scratched plastic collectors were tested consorting them with shell powder; on the second, the plastic collectors were tested consorted with shell powder, only shell powder and epinephrine as the metamorphosis stimulator. The quantification was carried out of the larvae settled in the plastic collectors, and of the recovery and integrity of the spats after their detachment. The first experiment has shown a recovery rate of 48.83% of the spats in comparison with the D larvae used. From this percentage, 4.9% settled in the plastic collectors and 43.93% in shell powder. The second experiment revealed 55.78% regarding the settled spats in comparison with the total of larvae used (using epinephrine), 78.62% in the treatment with the collector plus shell powder and 58.33% in the treatment only with shell powder. Thus, the use of the collector plus shell powder resulted in a greater spat recovery when compared to the other treatments.

  9. Disease prevalence and snail predation associated with swell-generated damage on the threatened coral, Acropora palmata (Lamarck)

    USGS Publications Warehouse

    Bright, Allan J.; Rogers, Caroline S.; Brandt, Marilyn E.; Muller, Erinn; Smith, Tyler B.

    2016-01-01

    Disturbances such as tropical storms cause coral mortality and reduce coral cover as a direct result of physical damage. Storms can be one of the most important disturbances in coral reef ecosystems, and it is crucial to understand their long-term impacts on coral populations. The primary objective of this study was to determine trends in disease prevalence and snail predation on damaged and undamaged colonies of the threatened coral species, Acropora palmata, following an episode of heavy ocean swells in the US Virgin Islands (USVI). At three sites on St. Thomas and St. John, colonies of A. palmata were surveyed monthly over 1 year following a series of large swells in March 2008 that fragmented 30–93% of colonies on monitored reefs. Post-disturbance surveys conducted from April 2008 through March 2009 showed that swell-generated damage to A. palmata caused negative indirect effects that compounded the initial direct effects of physical disturbance. During the 12 months after the swell event, white pox disease prevalence was 41% higher for colonies that sustained damage from the swells than for undamaged colonies (df = 207, p = 0.01) with greatest differences in disease prevalence occurring during warm water months. In addition, the corallivorous snail, Coralliophila abbreviata, was 46% more abundant on damaged corals than undamaged corals during the 12 months after the swell event (df = 207, p = 0.006).

  10. Quick characterization of uronic acid-containing polysaccharides in 5 shellfishes by oligosaccharide analysis upon acid hydrolysis.

    PubMed

    Liu, Bin; Lu, Jiaojiao; Ai, Chunqing; Zhang, Bao; Guo, Li; Song, Shuang; Zhu, Beiwei

    2016-11-29

    Uronic acid-containing polysaccharides (UACPs) including well-known glycosaminoglycans (GAGs) and some non-GAGs exist widely in animal kingdom. Although numerous methods have been established to analyze GAGs, few methods are available for non-GAG UACPs. In the present study, a protocol to identify all kinds of UACPs with repeating disaccharide units of hexosamine and uronic acid was demonstrated, and UACP components in five shellfishes, namely Turritella fortilirata Sowerby (GTF), Batillaria zonalis (GBZ), Nassarius variciferus (GNV), Monodonta labio Linnaeus (GML), and Argopecten irradians Lamarck (BAI) were primarily revealed. After a simple isolation procedure, crude polysaccharides were depolymerized by controlled acid hydrolysis, and then the resulting oligosaccharides were detected by HPLC coupled with mass spectrometer after 1-phenyl-3-methyl-5-pyrazolone (PMP) labeling. According to chromatograms using the triple quadrupole mass spectrometer in the multiple reaction monitoring (MRM) mode, chondroitin sulfate (CS) was found in GNV and GML, a non-GAG named abalone gonad sulfated polysaccharide (AGSP) with a backbone of →4)-β-GlcA-(1 → 2)-α-Man-(1→ repeating units in GBZ, and both of AGSP and CS in BAI and GTF. Further characterization of tetrasaccharides and sulfated/acetylated disaccharides by HPLC combined with an ion trap mass spectrometer confirmed the structural identification of CS and AGSP, and indicated CS in GTF and BAI was Type C. These results suggest the 5 mollusks as potential resources for CS and AGSP. And the analysis protocol presented in this study was powerful and effective for quick characterization of UACPs including GAGs as well as non-GAGs in complicated matrix.

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

    NASA Astrophysics Data System (ADS)

    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

  12. The occurrence of domoic acid linked to a toxic diatom bloom in a new potential vector: the tunicate Pyura chilensis (piure).

    PubMed

    López-Rivera, Américo; Pinto, Maricela; Insinilla, Andrea; Suárez Isla, Benjamín; Uribe, Eduardo; Alvarez, Gonzalo; Lehane, Mary; Furey, Ambrose; James, Kevin J

    2009-11-01

    The tunicate Pyura chilensis (Molina, 1782); Phylum Chordata; Subphylum Urochordata; Class Ascidiacea, common local name "piure" or sea squirt; a filter-feeder (plankton and suspended particles) sessile species; may play an important role in monitoring domoic acid (DA) the principal toxic component of Amnesic Shellfish Poisoning (ASP). Significant DA concentrations have been determined in tunicate samples, collected during a recent ASP outbreak in Bahía Inglesa, an important scallop (Argopecten purpuratus) farming area. Several infaunal species were tested for the presence of DA, in addition to the usual scallop monitoring programme. DA was found at sub-toxic levels in filtering bivalves such as mussels (Mytilus chilensis), large mussels (Aulacomya ater) and clams (Protothaca thaca) (6.4, 5.4 and 4.7 microg DA/g tissue respectively). Of particular interest was the observation of significant accumulations of toxic Pseudo-nitzschia sp. diatoms in the internal siphon and atrium spaces of the tunicate. Toxin distribution within major tunicate organs was heterogeneous with 8.7-15.5 microg DA/g in edible tissues, 14.9-17.9 microg DA/g in the fecal material and 13.6-32.7 microg DA/g in the gut content. DA was determined by HPLC-UV and confirmed by diode-array detection and LC-MS/MS analysis. This is the first report of the presence of DA in a tunicate that is regularly consumed by coastal populations. These results confirm the need to include these organisms in sanitation programs for marine toxins.

  13. Total and methyl-mercury content in bivalves, Mytilus galloprovincialis Lamarck and Ostrea edulis Linnaeus: relationship of biochemical composition and body size

    SciTech Connect

    Najdek, M.; Sapunar, J.

    1987-07-01

    Mussels and oysters are of interest to pollution ecologists because they are widely distributed, suspension feeding invertebrates and are likely to accumulate pollutants from their environment (Goldberg 1975). Many authors have estimated the relation between the concentration of metals in the flesh and various biotic and abiotic parameters. Body mass (estimated in dry weight) is evidently an important factor governing the uptake of metals by these organisms. The highest concentrations of certain metals were often found in the smallest individuals. The relation between metal content and body size can best be described using Boyden's model which is useful for quantifying any physiological activities in relation to the dry weight of the specimens. In the present paper the authors describe the investigation into the relationship between total and methyl-mercury content and body mass in mussels and oysters.

  14. Shell fluctuating asymmetry in the sea-dwelling benthic bivalve Mytilus galloprovincialis (Lamarck, 1819) as morphological markers to detect environmental chemical contamination.

    PubMed

    Scalici, Massimiliano; Traversetti, Lorenzo; Spani, Federica; Malafoglia, Valentina; Colamartino, Monica; Persichini, Tiziana; Cappello, Simone; Mancini, Giuseppe; Guerriero, Giulia; Colasanti, Marco

    2017-02-10

    Investigations on asymmetries showed that deviations from perfect bilateral symmetry are interpreted as environmental changes inducing developmental instability. Since morphological abnormalities increase with pollution, deformations may be considered indicators of the organism exposition to pollution. Therefore, the onset of asymmetry in otherwise normally symmetrical traits has been used as a measure of some stresses as well. In this context, we studied how marine pollution affects the valve morphological alterations in the mussel Mytilus galloprovincialis. We used 180 specimens (30 per site) from the aquaculture area of Goro (River Po delta, northern Adriatic Sea), translocated, and released within 50 × 50 × 50 cm cages in five sites: two disturbed and one undisturbed near Naples (eastern Tyrrhenian Sea), and one disturbed and one undisturbed near Siracusa (western Ionian Sea). Disturbed sites were stressed by heavy industrialization and heavy tankers traffic of crude and refined oil, and were defined basing on sediment contamination. In particular, by the cone-beam computed tomography we obtained 3D virtual valve surfaces to be analyzed by the geometric morphometric techniques. Specifically, we focused the levels of the shell shape fluctuating asymmetry in relation to the degrees of marine pollution in different sites of the Tyrrhenian Sea. The Mahalanobis distances (interpreted as proxy of the individual shape asymmetry deviation from the mean asymmetry) significantly regressed with the sediment contamination gradient. Indeed, although the left-right differences were normally distributed in each studied site, the individual asymmetry scores (IAS) significantly varied amongst the investigated sites. IAS showed higher values in disturbed areas than those of undisturbed ones in both Tyrrhenian and Ionian Sea. Our results are consistent with past studies on molluscans and other taxa, demonstrating some detrimental effects of chemicals on organisms, although the investigated morphological marker did not discriminate the real disturbance source. Our findings indicate that the mussels act as a prognostic tool for sea pollution levels driving detrimental effects on benthic community.

  15. Broodstock diet effect on sea urchin Paracentrotus lividus (Lamarck, 1816) endotrophic larvae development: potential for their year-round use in environmental toxicology assessment.

    PubMed

    Repolho, Tiago Filipe Baptista da Rosa; Costa, Maria Helena; Luís, Orlando de Jesus; Gago, João André Evaristo de Matos

    2011-05-01

    The effect of captive broodstock diet on fertilization and endotrophic larvae development of the sea urchin Paracentrotus lividus was assessed. Maize grain and five inert pelleted diets were tested, during a three-month experimental period. Maize flour, wheat flour, soybean flour, maize/wheat flour (MWF) and maize/soybean flour mixes were used as vegetal sources for inert feed. Gonad index, percent egg fertilization and larvae malformation occurrence were compared with the results obtained from wild sea urchins (W). Whole egg total amino acid composition was concomitantly analyzed as a tool to explain eventual endotrophic larvae malformations caused by lack of specific nutrients. For all treatment groups (wild and captive), percent egg fertilization values above 96% were always observed, fulfilling the requisites (70-90%) necessary to conduct environmental monitoring bioassays, according to USEPA (2002). Similar values for normal percent larval development were only obtained from P. lividus broodstock subjected to an inert feeding diet based on a maize/wheat flour mix (85.0±1.45%), in comparison to wild P. lividus (82.5±1.75%). Likewise, no statistical differences on resultant whole egg total amino acid composition were observed between P. lividus fed MWF and wild treatments. Moreover, statistical differences between MWF and all the other captive feeding treatments were found for six out of the seventeen amino acids analyzed. This study demonstrates the possibility to obtain high values for P. lividus endotrophic larvae percent normal development based on broodstock held in captivity as long as an appropriate inert diet is provided.

  16. Immature stages of giants: morphology and growth characteristics of Goliathus Lamarck, 1801 larvae indicate a predatory way of life (Coleoptera, Scarabaeidae, Cetoniinae)

    PubMed Central

    Vendl, Tomáš; Šípek, Petr

    2016-01-01

    Abstract The third larval instar of Goliathus goliatus (Drury, 1770), Goliathus orientalis Moser, 1909 and Goliathus albosignatus Boheman, 1857 are described and illustrated for the first time and compared with the immature stages of other Cetoniinae. Larval development of Goliathus goliatus is investigated under laboratory conditions, with particular emphasis on food requirements. These results support the obligatory requirement of proteins in the larval diet. The association between larval morphological traits (e. g., the shape of the mandibles and pretarsus, presence of well-developed stemmata) and larval biology is discussed. Based on observations and the data from captive breeds it is concluded that a possible shift from pure saprophagy to an obligatory predaceous way of larval life occurred within the larvae of this genus, which may explain why these beetles achieve such an enormous size. PMID:27829788

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  18. EFFECT OF DIET QUALITY ON NUTRIENT ALLOCATION TO THE TEST AND ARISTOTLE'S LANTERN IN THE SEA URCHIN LYTECHINUS VARIEGATUS (LAMARCK, 1816).

    PubMed

    Heflin, Laura Elizabeth; Gibbs, Victoria K; Powell, Mickie L; Makowsky, Robert; Lawrence, Addison L; Lawrence, John M

    2012-08-01

    Small adult (19.50 ± 2.01g wet weight) Lytechinus variegatus were fed eight formulated diets with different protein (12 to 36% dry weight as fed) and carbohydrate (21 to 39 % dry weight) levels. Each sea urchin (n = 8 per treatment) was fed a daily ration of 1.5% of the average body weight of all individuals for 9 weeks. Akaike information criterion scores were used to compare six different dietary composition hypotheses for eight growth measurements. For each physical growth response, different mathematical models representing a priori hypotheses were compared using the Akaike Information Criterion (AIC) score. The AIC is one of many information-theoretic approaches that allows for direct comparison of non-nested models with varying number of parameters. Dietary protein level and protein: energy ratio were the best models for prediction of test diameter increase. Dietary protein level was the best model of test with spines wet weight gain and test with spines dry matter production. When the Aristotle's lantern was corrected for size of the test, there was an inverse relationship with dietary protein level. Log transformed lantern to test with spines index was also best associated with the dietary protein model. Dietary carbohydrate level was a poor predictor for growth parameters. However, the protein × carbohydrate interaction model was the best model of organic content (% dry weight) of the test without spines. These data suggest that there is a differential allocation of resources when dietary protein is limiting and the test with spines, but not the Aristotle's lantern, is affected by availability of dietary nutrients.

  19. Mixed effects of elevated pCO2 on fertilisation, larval and juvenile development and adult responses in the mobile subtidal scallop Mimachlamys asperrima (Lamarck, 1819).

    PubMed

    Scanes, Elliot; Parker, Laura M; O'Connor, Wayne A; Ross, Pauline M

    2014-01-01

    Ocean acidification is predicted to have severe consequences for calcifying marine organisms especially molluscs. Recent studies, however, have found that molluscs in marine environments with naturally elevated or fluctuating CO2 or with an active, high metabolic rate lifestyle may have a capacity to acclimate and be resilient to exposures of elevated environmental pCO2. The aim of this study was to determine the effects of near future concentrations of elevated pCO2 on the larval and adult stages of the mobile doughboy scallop, Mimachlamys asperrima from a subtidal and stable physio-chemical environment. It was found that fertilisation and the shell length of early larval stages of M. asperrima decreased as pCO2 increased, however, there were less pronounced effects of elevated pCO2 on the shell length of later larval stages, with high pCO2 enhancing growth in some instances. Byssal attachment and condition index of adult M. asperrima decreased with elevated pCO2, while in contrast there was no effect on standard metabolic rate or pHe. The responses of larval and adult M. asperrima to elevated pCO2 measured in this study were more moderate than responses previously reported for intertidal oysters and mussels. Even this more moderate set of responses are still likely to reduce the abundance of M. asperrima and potentially other scallop species in the world's oceans at predicted future pCO2 levels.

  20. Hermaphroditism among dioecious Tagelus plebeius (Lightfoot, 1786) (Mollusca, Psammobiidae) and Iphigenia brasiliana (Lamarck, 1818) (Mollusca, Donacidae) on the Cachoeira River estuary, Ilhéus, Bahia, Brazil.

    PubMed

    Ceuta, L O; Boehs, G; Santos, J J B

    2010-02-01

    The samples of Tagelus plebeius and Iphigenia brasiliana were manually collected on the Cachoeira River estuary region (Ilhéus, BA, Brazil) between August 2005 and August 2006, with a periodicity of 15 days, with 20 animals collected/sampled, performing 500 samples from each species. The animals were measured, eviscerated and kept in solution of Davidson and after 24-30 hours, they were transferred to ethanol 70%. The material was processed for routine histology, with paraffin embedding, obtaining 7 microm thick slices, stained with Harris hematoxilin and Eosin (HE). By light microscopy analysis, 2 cases of hermaphroditism (0.4%) in T. plebeius samples and one case (0.2%) in I. brasiliana were registered with predominance of female over male follicles.

  1. The effects of chronic inorganic and organic phosphate exposure on bactericidal activity of the coelomic fluid of the sea urchin Lytechinus variegatus (Lamarck) (Echinodermata: Echinoidea).

    PubMed

    Böttger, S Anne; McClintock, James B

    2009-07-01

    The sea urchin Lytechinus variegatus can survive chronic exposure to sodium phosphate (inorganic phosphate) concentrations as high as 3.2 mg L-1, and triethyl phosphate (organic phosphate) concentrations of 1000 mg L-1. However, chronic exposure to low (0.8 mg L-1 inorganic and 10 mg L-1 organic phosphate), medium (1.6 mg L-1 inorganic and 100 mg L-1 organic phosphate) or high (3.2 mg L-1 inorganic and 1000 mg L-1 organic phosphate) sublethal concentrations of these phosphates inhibit bactericidal clearance of the marine bacterium Vibrio sp. Bacteria were exposed to coelomic fluid collected from individuals maintained in either artificial seawater, or three concentrations of either inorganic phosphate or organic phosphate. Sterile marine broth, natural seawater and cell free coelomic fluid (cfCF) were employed as controls. Bacterial survival indices were measured at 0, 24 and 48 h periods once a week for four weeks. Bacteria were readily eliminated from the whole coelomic fluid (wCF) of individuals maintained in artificial seawater. Individuals maintained in inorganic phosphates were able to clear bacteria following a two week exposure period, while individuals maintained at even low concentrations of organic phosphates failed to clear all bacteria from their coelomic fluid. Exposure to phosphates represses antimicrobial defenses and may ultimately compromise survival of L. variegatus in the nearshore environment.

  2. Mixed Effects of Elevated pCO2 on Fertilisation, Larval and Juvenile Development and Adult Responses in the Mobile Subtidal Scallop Mimachlamys asperrima (Lamarck, 1819)

    PubMed Central

    Scanes, Elliot; Parker, Laura M.; O’Connor, Wayne A.; Ross, Pauline M.

    2014-01-01

    Ocean acidification is predicted to have severe consequences for calcifying marine organisms especially molluscs. Recent studies, however, have found that molluscs in marine environments with naturally elevated or fluctuating CO2 or with an active, high metabolic rate lifestyle may have a capacity to acclimate and be resilient to exposures of elevated environmental pCO2. The aim of this study was to determine the effects of near future concentrations of elevated pCO2 on the larval and adult stages of the mobile doughboy scallop, Mimachlamys asperrima from a subtidal and stable physio-chemical environment. It was found that fertilisation and the shell length of early larval stages of M. asperrima decreased as pCO2 increased, however, there were less pronounced effects of elevated pCO2 on the shell length of later larval stages, with high pCO2 enhancing growth in some instances. Byssal attachment and condition index of adult M. asperrima decreased with elevated pCO2, while in contrast there was no effect on standard metabolic rate or pHe. The responses of larval and adult M. asperrima to elevated pCO2 measured in this study were more moderate than responses previously reported for intertidal oysters and mussels. Even this more moderate set of responses are still likely to reduce the abundance of M. asperrima and potentially other scallop species in the world’s oceans at predicted future pCO2 levels. PMID:24733125

  3. EFFECT OF DIET QUALITY ON NUTRIENT ALLOCATION TO THE TEST AND ARISTOTLE’S LANTERN IN THE SEA URCHIN LYTECHINUS VARIEGATUS (LAMARCK, 1816)

    PubMed Central

    Heflin, Laura Elizabeth; Gibbs, Victoria K; Powell, Mickie L; Makowsky, Robert; Lawrence, Addison L; Lawrence, John M

    2014-01-01

    Small adult (19.50 ± 2.01g wet weight) Lytechinus variegatus were fed eight formulated diets with different protein (12 to 36% dry weight as fed) and carbohydrate (21 to 39 % dry weight) levels. Each sea urchin (n = 8 per treatment) was fed a daily ration of 1.5% of the average body weight of all individuals for 9 weeks. Akaike information criterion scores were used to compare six different dietary composition hypotheses for eight growth measurements. For each physical growth response, different mathematical models representing a priori hypotheses were compared using the Akaike Information Criterion (AIC) score. The AIC is one of many information-theoretic approaches that allows for direct comparison of non-nested models with varying number of parameters. Dietary protein level and protein: energy ratio were the best models for prediction of test diameter increase. Dietary protein level was the best model of test with spines wet weight gain and test with spines dry matter production. When the Aristotle’s lantern was corrected for size of the test, there was an inverse relationship with dietary protein level. Log transformed lantern to test with spines index was also best associated with the dietary protein model. Dietary carbohydrate level was a poor predictor for growth parameters. However, the protein × carbohydrate interaction model was the best model of organic content (% dry weight) of the test without spines. These data suggest that there is a differential allocation of resources when dietary protein is limiting and the test with spines, but not the Aristotle’s lantern, is affected by availability of dietary nutrients. PMID:25431520

  4. Macrobenthic Communities of the Lower Chesapeake Bay.

    DTIC Science & Technology

    1984-10-01

    ECHINODERMATA :ECHINOIDEA Arbacij Runlctulata (Lamarck) Echinarachnius Parma (Larmack) ECHINODERMATA :HOLOTHURO-DEA Holothuroidea spp. Leptosynapta ... inhaerens (Ayres) ECHINODERMATA :OPHIUROIDEA Ophiuroidea spp. * HEMICHORDATA Saccoglossus kowalewskii (Agassiz) CHORDATA :CEPHALOCHORDATA Branchiostoma

  5. Restoration Lessons Learned from Bay Scallop Habitat Models

    EPA Science Inventory

    Habitat quality and quantity are important factors to consider when restoring bay scallop (Argopecten irradians) populations; however, data linking habitat attributes to bay scallop populations are lacking. This information is essential to guide restoration efforts to reverse sc...

  6. Demonstration of an Integrated Compliance Model for Predicting Copper Fate and Effects in DoD Harbors

    DTIC Science & Technology

    2008-12-01

    development tests with mussels (M. galloprovin- cialis) and purple sea urchins ( S . purpuratus ) expressed as water concentration or whole-body residues...this study for M. galloprovincialis and S . purpuratus larvae are considerably higher than the median lethal accumulation (LA50) values developed by...accumulation for M. galloprovin- cialis and S . purpuratus in two waters from San Diego Bay. Table 8 lists parameters used for modeled values. Data

  7. Sediment Quality Characterization Naval Station San Diego

    DTIC Science & Technology

    1999-01-01

    Neanthes sp. Sediment % Survival ៀ% > 80% S . purpuratus 1 Pore Water % Normal Larval ៀ% > 80% Development Haliotis sp. 1 Subsurface % Normal Shell ៀ...C. gigas survival, R. abronius survival, S . purpuratus development , and P450 induction. Of 16 sur- vival tests with G. japonica, 10 showed effects...showed effects in S . purpuratus development , and one showed no effects. Effects were observed using R. abronius at four sites and no effects were

  8. 50 CFR Appendix A to Part 622 - Species Tables

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Agaricidae Agaricia agaricites, Lettuce leaf coral A. fragilis, Fragile saucer A. lamarcki, Lamarck's sheet A. tenuifolia, Thin leaf lettuce Leptoseris cucullata, Sunray lettuce Family Astrocoeniidae Stephanocoenia.... Gastropods—Class Gastropoda Family Elysiidae Tridachia crispata, Lettuce sea slug Family Olividae...

  9. 50 CFR Appendix A to Part 622 - Species Tables

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Agaricidae Agaricia agaricites, Lettuce leaf coral A. fragilis, Fragile saucer A. lamarcki, Lamarck's sheet A. tenuifolia, Thin leaf lettuce Leptoseris cucullata, Sunray lettuce Family Astrocoeniidae Stephanocoenia.... Gastropods—Class Gastropoda Family Elysiidae Tridachia crispata, Lettuce sea slug Family Olividae...

  10. 50 CFR Appendix A to Part 622 - Species Tables

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., Lettuce leaf coral A. fragilis, Fragile saucer A. lamarcki, Lamarck's sheet A. tenuifolia, Thin leaf lettuce Leptoseris cucullata, Sunray lettuce Family Astrocoeniidae Stephanocoenia michelinii, Blushing... A. Gastropods—Class Gastropoda Family Elysiidae Tridachia crispata, Lettuce sea slug Family...

  11. 50 CFR Appendix A to Part 622 - Species Tables

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., Lettuce leaf coral A. fragilis, Fragile saucer A. lamarcki, Lamarck's sheet A. tenuifolia, Thin leaf lettuce Leptoseris cucullata, Sunray lettuce Family Astrocoeniidae Stephanocoenia michelinii, Blushing... A. Gastropods—Class Gastropoda Family Elysiidae Tridachia crispata, Lettuce sea slug Family...

  12. Evolution.

    ERIC Educational Resources Information Center

    Mayr, Ernst

    1978-01-01

    Traces the history of evolution theory from Lamarck and Darwin to the present. Discusses natural selection in detail. Suggests that, besides biological evolution, there is also a cultural evolution which is more rapid than the former. (MA)

  13. Periodic Matrix Model to Evaluate Management Strategies for Bay Scallop (Argopectin iraddians) Populations

    EPA Science Inventory

    Within the last twenty years total harvests of bay scallops (Argopecten irradians) have dwindled in the southern New England Region, and one of the reasons often cited for this decline is drastic changes to their habitat, specifically eelgrass. To counteract these declines, bay ...

  14. Using a System Level Approach to Bay Scallop Enhancement and Management

    EPA Science Inventory

    Within the last twenty years total harvests of bay scallops (Argopecten irradians) have dwindled in the southern New England Region. Management of scallop populations has been underway on Martha’s Vineyard Island to provide the public with a fishery, and have included a com...

  15. An Annotated Bibliography on the Biological Effects of Constructing Channels, Jetties, and other Coastal Structures.

    DTIC Science & Technology

    1983-01-01

    Strongylocentrotus purpuratus (Stimpson) and S . franciscanus (A. Ag.) were manipulated in 21 experimental cells constructed on the rocks of the entrance channel...breakwater. Cells were set up with S . purpuratus only, with S . francis- canus only, and with half of the biomass of each species. The rate of change of...NO. 3. RECIPIENT’S CATALOG NUMBER MR 83-2 1jq6 i 4. TITLE (and Subtitle) S . TYPE OF REPORT & PERIOD COVERED AN ANNOTATED BIBLIOGRAPHY ON THE

  16. Isolation and Characterization of Spicule Matrix Protein.

    DTIC Science & Technology

    2007-11-02

    responsible for the observed PCP activity in S . purpuratus , then its function will be essential for collagen deposition and therefore sea urchin development ....PCP) activity in S . purpuratus extracts containing suBMP- 1. This PCP activity is heat labile, and demonstrates both time and concentration dependent...in the developing sea urchin embryo, as well as for calcium carbonate deposition into growing spicules in primary mesenchyme cell culture. Disruption

  17. Skeletogenesis in sea urchin interordinal hybrid embryos.

    PubMed

    Brandhorst, B P; Davenport, R

    2001-07-01

    Reciprocal interordinal crosses were made between the sea urchins Strongylocentrotus purpuratus and Lytechinus pictus. Previous research indicated that the expression of many L. pictus genes is reduced in the hybrid embryos. The S. purpuratus gene encoding the spicule matrix protein SM50 and the L. pictus gene encoding its orthologue LSM34 were both expressed at normal levels per gene copy in hybrid embryos, and in about 32 skeletogenic primary mesenchyme cells (PMCs) in hybrid and natural gastrulae. In many embryos of all crosses, 16 PMCs initially ingressed, while 32-64 PMCs were present in gastrulae. The skeletal spicules of most hybrid plutei were predominantly like those of S. purpuratus, consistent with the predominance of expression of S. purpuratus genes in hybrid embryos. The spicules of some hybrid plutei showed features characteristic of L. pictus, such as recurrent rods, branched body rod tips, or convergent ventral transverse rods; a few hybrid spicules were predominantly like those of L. pictus. Based on our observations and the literature, we propose the following. Cues from the ectodermal epithelium position the PMCs as they elaborate the initial triradiate spicules. Their orientation and outgrowth appears to be responsible for the convergence of the tips of body rods in most S. purpuratus and hybrid embryos, unlike in most L. pictus embryos. Variations among hybrid and natural embryos in skeletal branching pattern reflect differences in interpretation by PMCs of patterning cues produced by the ectodermal epithelium that probably have similar spatial distributions in the two species.

  18. Weathering rate of male rubber septa impregnator sex pheromone of Sweetpotato Weevil, Cylas formicarius elegantulus (Coleoptera: Brentidae), in East Hawaii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, sweet potato, Ipomoea batatas (L.) Lamarck, production in Hawaii has been increasing, reaching 190 harvested ha, with a total production of 3.78 million kg in 2009. Sweet potato production in Hawaii is hindered by three major quarantine pests, for which only one, the sweetpotato we...

  19. Trapping sweetpotato weevil, Cylas formicarius elegantulus (Coleoptera: Brentidae), with high doses of sex pheromone: Catch enhancement and weathering rate in Hawaii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato, Ipomoea batatas (L.) Lamarck, one of the top ten staple crops produced worldwide, has increased in production in Hawaii in recent years. The sweetpotato weevil, Cylas formicarius elegantulus (Summers)(Coleoptera: Brentidae), is a major economic and quarantine pest of sweetpotato in Hawa...

  20. Students' Preconceptions about Evolution: How Accurate Is the Characterization as "Lamarckian" when Considering the History of Evolutionary Thought?

    ERIC Educational Resources Information Center

    Kampourakis, Kostas; Zogza, Vasso

    2007-01-01

    In this paper, the main points of Lamarck's and Darwin's theoretical conceptual schemes about evolution are compared to those derived from 15 years old students' explanations of evolutionary episodes. We suggest that secondary students' preconceptions should not be characterized as "Lamarckian", because they are essentially different from the…

  1. Theories of Evolution, Science (Experimental): 5315.42.

    ERIC Educational Resources Information Center

    Adams, Joseph P.

    This is an in-depth course of study of the historical attempts to explain the evolutionary process and of recent developments pertinent to the study of biomedical evolution. Topics included in the module are: (1) ancient concepts of the evolutionary process; (2) various aspects of Lamarckism, Darwinism and neo-Darwinism, including substantiating…

  2. Green light synergistically enhances male sweetpotato weevil sex pheromone response

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato, Ipomoea batatas (L.) Lamarck, commercially grown in over 100 countries, is the 7th most important staple crop in the world. Sweetpotato weevil is a major pest of sweetpotato in most areas of cultivation, the feeding of which induces production in the sweetpotato root of extremely bitter...

  3. Life history parameters of the biocontrol agent Gratiana spadicea (Chrysomelidae), reared on the natural host plant Solanum sisymbriifolium and the non-target crop Solanum melongena (Solanaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gratiana spadicea (Klug), a leaf-feeding tortoise beetle native to South America, was released in South Africa for the biological control of Solanum sisymbriifolium Lamarck (wild tomato), despite its ability to develop on cultivated eggplant (Solanum melongena L.) during laboratory host-specificity ...

  4. Problem-Solving Exercises and Evolution Teaching

    ERIC Educational Resources Information Center

    Angseesing, J. P. A.

    1978-01-01

    It is suggested that the work of Kammerer provides suitable material, in the form of case studies on which to base discussions of Lamarckism versus Darwinism. A set of structured problems is described as an example of possible problem-solving exercises, and further experiments to extend Kammerer's work are outlined. (Author/MA)

  5. The geology of the Inconsolable Range, east-central Sierra Nevada, California

    SciTech Connect

    Hathaway, G.M; Reed, W.E. . Dept. of Earth and Space Sciences)

    1993-04-01

    Detailed mapping of the Inconsolable Range in the east-central Sierra Nevada reveals a structurally and lithologically complex region of multi-phase intrusions. Some plutons are compositionally-zoned [e.g., Inconsolable (100 Ma) and Lamarck (90 Ma)]; others may be the result of magma mixing. Intrusive borders vary from brittle to ductile and sharp to gradational, and are bounded by contact aureoles of varying metamorphic grade. A shear zone (Long Lake shear zone -- LLSZ) bounds the western margin of the Inconsolable Range for 8 km; this is truncated in the south by the Cretaceous Lamarck intrusive suite, and is tectonically overlain in the north by the Bishop Creek Pendant (Ordovician ). The LLSZ is a complex zone of interleaved septa of biotite schists, orthogneisses, aplitic screens, and calc-silicate gneisses approximately 500 to 800 m wide. Preliminary interpretation suggests that the LLSZ is the sheared remnant of a Triassic-Jurassic igneous terrane complete with metasedimentary pendants. Juxtaposition of greenschist facies meta-sedimentary rocks of the Chocolate Peak klippe over highly deformed amphibolite grade meta-igneous rocks of the LLSZ postdates movement along the LLSZ. Metamorphic grades suggest that deeper structural levels are exposed within the LLSZ near its southern terminus. Twenty plutonic lithologies have been mapped and informally named (e.g., Spotted biotite quartz diorite), including 3 compositionally-zoned plutons. Zonation within the Lamarck, Inconsolable, and Spotted intrusions are the result of multiple emplacement events into partially crystallized host plutons. Along the eastern border of the Lamarck intrusive suite field evidence indicates four separate intrusive events. The Inconsolable body is a compositionally-zoned biotite, clinopyroxene, quartz diorite with irregular granodiorite margins. The base of the Spotted intrusion appears to have been magmatically eroded by a pulse of the younger Lamarck intrusion.

  6. Warmer temperatures reduce the influence of an important keystone predator.

    PubMed

    Bonaviri, Chiara; Graham, Michael; Gianguzza, Paola; Shears, Nick T

    2017-01-11

    Predator-prey interactions may be strongly influenced by temperature variations in marine ecosystems. Consequently, climate change may alter the importance of predators with repercussions for ecosystem functioning and structure. In North-eastern Pacific kelp forests, the starfish Pycnopodia helianthoides is known to be an important predator of the purple sea urchin Strongylocentrotus purpuratus. Here we investigated the influence of water temperature on this predator-prey interaction by: (i) assessing the spatial distribution and temporal dynamics of both species across a temperature gradient in the northern Channel Islands, California, and (ii) investigating how the feeding rate of P. helianthoides on S. purpuratus is affected by temperature in laboratory tests. On average, at sites where mean annual temperatures were <14 °C, P. helianthoides were common, S. purpuratus was rare and kelp was persistent, whereas where mean annual temperatures exceeded 14 °C, P. helianthoides and kelp were rare and S. purpuratus abundant. Temperature was found to be the primary environmental factor influencing P. helianthoides abundance, and in turn P. helianthoides was the primary determinant of S. purpuratus abundance. In the laboratory, temperatures >16 °C (equivalent to summer temperatures at sites where P. helianthoides were rare) reduced predation rates regardless of predator and prey sizes, although larger sea urchins were consumed only by large starfishes. These results clearly demonstrate that the effect of P. helianthoides on S. purpuratus is strongly mediated by temperature, and that the local abundance and predation rate of P. helianthoides on sea urchins will likely decrease with future warming. A reduction in top-down control on sea urchins, combined with other expected impacts of climate change on kelp, poses significant risks for the persistence of kelp forests in the future.

  7. Gene Expression Analysis of Breast Cancer Progression

    DTIC Science & Technology

    2005-07-01

    living mammals using a bioluminescent reporter. Photochem Photobiol 66, 523-31 (1997). 30. Yingling, J. M., Blanchard, K. L. & Sawyer, J. S . Development of...homolog 1, actin-bundling protein (Strongylocentrotus 201564 s at 4.55 purpuratus ) FSCN1 216268 s at 4.47 jagged 1 (Alagille syndrome) JAG1 201417 at 4.45...bundling protein (Strongylocentrotus 210933 s at 3.99 purpuratus ) FSCN1 chemokine (C-X-C motif) ligand 1 (melanoma growth 204470 at 3.89 stimulating

  8. Determining the Fate and Ecological Effects of Copper and Zinc Loading in Estuarine Environments: A Multi-Disciplinary Program

    DTIC Science & Technology

    2005-12-01

    SD32 9-19~1 S . purpuratus • SD33 2-27~2 S . purpuratus ,,,,,,,,,,,,,,,,,,,,USEPA chronic WQC • SD32 9-19~1 M. galloprovinc iallis • SD33 2-27~2 M...CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING...ORGANIZATION NAME( S ) AND ADDRESS(ES) SPAWAR Systems Center San Diego,53560 Hull Street,San Diego,CA,92152 8. PERFORMING ORGANIZATION REPORT NUMBER 9

  9. Paleogenomics of echinoderms.

    PubMed

    Bottjer, David J; Davidson, Eric H; Peterson, Kevin J; Cameron, R Andrew

    2006-11-10

    Paleogenomics propels the meaning of genomic studies back through hundreds of millions of years of deep time. Now that the genome of the echinoid Strongylocentrotus purpuratus is sequenced, the operation of its genes can be interpreted in light of the well-understood echinoderm fossil record. Characters that first appear in Early Cambrian forms are still characteristic of echinoderms today. Key genes for one of these characters, the biomineralized tissue stereom, can be identified in the S. purpuratus genome and are likely to be the same genes that were involved with stereom formation in the earliest echinoderms some 520 million years ago.

  10. Adult Demography and Larval Processes in Coastal Benthic Populations: Intertidal Barnacles in Southern California and Baja California

    DTIC Science & Technology

    2005-09-01

    locentrotus franciscanus and S . purpuratus ) in California, 1400-1414, USA. Marine Ecology Progress Series, 111, 41-52. Pineda, J., 2000. Linking...Engineering Massachusetts Institute of Technology and Woods Hole Oceanographic Institution September 2005 Certified by S -Jestis Pineda Thesis Supervisor...0 1 .2 . S Y N O P S IS

  11. Sinclair and Dyes Inlets Toxicity Study: An Assessment of Copper Bioavailability and Toxicity in Surface Waters Adjacent to the Puget Sound Naval Shipyard and Intermediate Maintenance Facility

    DTIC Science & Technology

    2009-12-01

    galloprovincialis) and echinoderm (Strongylocentrotus purpuratus ) embryonic development : Conceptual, regulatory and environmental implications...Technical Coordinator, with contributions from members of the working group. The work plans were developed in cooperation with the Washington State...galloprovincialis) embryos in 48-hour embryo-larval development tests using protocols recommended by the U.S. Environmental Protection Agency (EPA) for

  12. Autonomous and non-autonomous differentiation of ectoderm in different sea urchin species.

    PubMed

    Wikramanayake, A H; Brandhorst, B P; Klein, W H

    1995-05-01

    During early embryogenesis, the highly regulative sea urchin embryo relies extensively on cell-cell interactions for cellular specification. Here, the role of cellular interactions in the temporal and spatial expression of markers for oral and aboral ectoderm in Strongylocentrotus purpuratus and Lytechinus pictus was investigated. When pairs of mesomeres or animal caps, which are fated to give rise to ectoderm, were isolated and cultured they developed into ciliated embryoids that were morphologically polarized. In animal explants from S. purpuratus, the aboral ectoderm-specific Spec1 gene was activated at the same time as in control embryos and at relatively high levels. The Spec1 protein was restricted to the squamous epithelial cells in the embryoids suggesting that an oral-aboral axis formed and aboral ectoderm differentiation occurred correctly. However, the Ecto V protein, a marker for oral ectoderm differentiation, was detected throughout the embryoid and no stomodeum or ciliary band formed. These results indicated that animal explants from S. purpuratus were autonomous in their ability to form an oral-aboral axis and to differentiate aboral ectoderm, but other aspects of ectoderm differentiation require interaction with vegetal blastomeres. In contrast to S. purpuratus, aboral ectoderm-specific genes were not expressed in animal explants from L. pictus even though the resulting embryoids were morphologically very similar to those of S. purpuratus. Recombination of the explants with vegetal blastomeres or exposure to the vegetalizing agent LiCl restored activity of aboral ectoderm-specific genes, suggesting the requirement of a vegetal induction for differentiation of aboral ectoderm cells.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Evolutionary and experimental change in egg volume, heterochrony of larval body and juvenile rudiment, and evolutionary reversibility in pluteus form.

    PubMed

    Bertram, Douglas F; Phillips, Nicole E; Strathmann, Richard R

    2009-01-01

    Heterochronic developmental plasticity of the juvenile rudiment and larval body of sea urchin larvae occurs in response to supply of food. Evolutionary increase in egg size can also be associated with earlier development of the juvenile rudiment. We examined effects of egg volume of feeding larvae on this heterochrony and other changes in larval form. (1) Evolutionary and experimental enlargements of egg volume did not accelerate formation of the rudiment relative to the larval body. Development of the larval body and juvenile rudiment was compared for the echinoids Strongylocentrotus purpuratus (with an egg of 78-82 microm) and Strongylocentrotus droebachiensis (with an egg of 150-160 microm diameter). Development of both larval body and rudiment were accelerated in S. droebachiensis relative to S. purpuratus but with greater acceleration of the larval body, so that the rudiment of S. droebachiensis was initiated at a later larval stage even though at an earlier age. Also, experimentally doubling the egg volume of S. purpuratus did not accelerate development of the juvenile rudiment relative to the larval body. (2) Both species exhibited similar plasticity in timing of rudiment development in response to food supplies. (3) Doubling egg volume of S. purpuratus produced a larval form more similar to that of S. droebachiensis. This result mirrors previous experiments in which larvae from half embryos of S. droebachiensis were more similar to larvae of S. purpuratus. Many of the effects of egg volume on larval form are similar against either species' genetic background and are thus evolutionarily reversible effects on larval form.

  14. Exposure of a late cretaceous layered mafic-felsic magma system in the central Sierra Nevada batholith, California

    USGS Publications Warehouse

    Coleman, D.S.; Glazner, A.F.; Miller, J.S.; Bradford, K.J.; Frost, T.P.; Joye, J.L.; Bachl, C.A.

    1995-01-01

    New U-Pb zircon ages for the Lamarck Granodiorite, associated synplutonic gabbro and diorite plutons, and two large mafic intrusive complexes that underlie them in the Sierra Nevada batholith are 92??1 Ma. These ages establish the Late Cretaceous as a period of extensive mafic-felsic magmatism in the central part of the batholith, and confirm the significance of mafic magmatism in the evolution of the voluminous silicic plutions in the Sierran arc. The lack of significant zircon inheritance in any of the units analyzed supports isotopic evidence that the Lamarck and other Late Cretaceous Sierran plutons were derived predominantly from young crust. Recognition of an extensive mafic-felsic magma system in the Sierra Nevada batholith emphasizes the importance of basaltic liquids in the evolution of continental crust in arc settings. ?? 1995 Springer-Verlag.

  15. Weismann, Wittgenstein and the homunculus fallacy.

    PubMed

    Smit, Harry

    2010-09-01

    A problem that has troubled both neo-Darwinists and neo-Lamarckians is whether instincts involve knowledge. This paper discusses the contributions to this problem of the evolutionary biologist August Weismann and the philosopher Ludwig Wittgenstein. Weismann discussed an empirical homunculus fallacy: Lamarck's theory mistakenly presupposes a homunculus in the germ cells. Wittgenstein discussed a conceptual homunculus fallacy which applies to Lamarck's theory: it is mistaken to suppose that knowledge is stored in the brain or DNA. The upshot of these two fallacies is that instincts arise through a neo-Darwinian process but are not cognitions in the sense that they involve (the recollection of stored) knowledge. Although neo-Lamarckians have rightly argued that learning processes may contribute to the development of instincts, their ideas about the role of knowledge in the evolution and development of instincts are mistaken.

  16. Essential Shift: Scientific Revolution in the 20th Century

    DTIC Science & Technology

    1993-05-17

    Lamarck, and the Scottish geologist Charles Lyell .5’ Based on the extensive observational research that he conducted on his 1831-1836 voyage on HMS...within the Newtonian paradigm in the nineteenth century, the science of thermodynamics and Charles Darwin’s theory of biological evolution, a scientific...briefly examine histories of thermodynamics and evolution, their relationship with the Newtonian paradigm and with each other. 39 Charles Darwin developed

  17. Application of toxicity identification procedures to the echinoderm fertilization assay to identify toxicity in a municipal effluent

    SciTech Connect

    Bailey, H.C.; Miller, J.L.; Miller, M.J.; Dhaliwal, B.S.

    1995-12-01

    Toxicity was detected in a municipal effluent with the echinoderm fertilization assay. Dendraster excentricus appeared more sensitive to the effluent than did Strongylocentrotus purpuratus. A Phase 1 toxicity identification evaluation (TIE) was conducted using procedures adapted to the echinoderm fertilization bioassay. The Phase 1 TIE implicated cationic metals as the cause of toxicity, and follow-up investigations suggested that copper was the primary cation responsible. As part of the TIE, bioassays were conducted on ammonia and several cations. No-observable-effect concentrations for D. excentricus were > 13.4 {micro}g/L (Ag), > 9.4 {micro}g/L (Cd), 3.8 to 13.1 {micro}g/L (Cu), > 0.7 {micro}g/L (Hg), and 10 mg/L (N, as total ammonia). The data also suggested that interspecific differences in sensitivity to copper and ammonia exist between Dendraster excentricus and Strongylocentrotus purpuratus.

  18. The transcriptome of the sea urchin embryo.

    PubMed

    Samanta, Manoj P; Tongprasit, Waraporn; Istrail, Sorin; Cameron, R Andrew; Tu, Qiang; Davidson, Eric H; Stolc, Viktor

    2006-11-10

    The sea urchin Strongylocentrotus purpuratus is a model organism for study of the genomic control circuitry underlying embryonic development. We examined the complete repertoire of genes expressed in the S. purpuratus embryo, up to late gastrula stage, by means of high-resolution custom tiling arrays covering the whole genome. We detected complete spliced structures even for genes known to be expressed at low levels in only a few cells. At least 11,000 to 12,000 genes are used in embryogenesis. These include most of the genes encoding transcription factors and signaling proteins, as well as some classes of general cytoskeletal and metabolic proteins, but only a minor fraction of genes encoding immune functions and sensory receptors. Thousands of small asymmetric transcripts of unknown function were also detected in intergenic regions throughout the genome. The tiling array data were used to correct and authenticate several thousand gene models during the genome annotation process.

  19. Ecotoxicological Response of Marine Organisms to Inorganic and Organic Sediment Amendments in Laboratory Exposures

    DTIC Science & Technology

    2011-08-15

    Critical tissue copper residues for marine bivalve (Mytilus galloprovin- cialis) and echinoderm (Strongylocentrotus purpuratus ) embryonic develop - ment...laboratory exposures 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK...UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) SPAWAR Systems Center Pacific,San Diego,CA,92152 8. PERFORMING ORGANIZATION REPORT

  20. Survey of Methods to Assess the Toxicological Impact of Hazardous Waste Disposal Sites on Aquatic Ecosystems

    DTIC Science & Technology

    1989-07-01

    used are Strongylocentrotus drobachiensis, S . purpuratus , and Arabacia punctulata. A variety of test methodologies has been worked out which examines...fertilization success and arrest development in early developmental stages in sea urchins (Kobayashi, 1984). At high metal concentrations, fertilization of... development ," Marine Pollution Bulletin, Vol. 7, pp. 124-127. Lonning, S ., 1977. "The effects of crude Ekofisk oil and oil products on marine fish larvae

  1. A Literature Survey on the Wetland Vegetation of Alaska.

    DTIC Science & Technology

    1982-08-01

    Pitmegea River but about 5 miles inland shrubs are well developed with Salix alaxensis 2 to 6 ft tall and S . glauca and S . richardsonii 1 to 4 ft high... develop directly on bare alluvial gravels, the two most important species being Salix pulchra and S . alaxensis. Near the coast the latter is the most common...depth greater than 1 m. The most abundant species * are Crepis nana, Erigeron purpuratus , Epilobium latifolium, Artemisia ’* S tilesii, A. alaskana, A

  2. Bioluminescence Flow Visualization in the Ocean: An Initial Strategy Based on Laboratory Experiments

    DTIC Science & Technology

    2002-01-01

    development of the 408-416. purple sea urchin Strongylocentrotus purpuratus . Biological Rohr, J., Latz, M.I., Fallon, S ., Nauen, J.C., Hendricks, E...experiments 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHORS 5d. PROJECT NUMBER Jim Rohr, Stewart Fallon’ Mark Hyman2 S . TASK NUMBER Michael I...Latz 3 51. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION ’SSC San Diego 2Coastal Systems Station

  3. Annotated Bibliography of Bioassays Related to Sediment Toxicity Testing in Washington State

    DTIC Science & Technology

    1990-10-01

    REVIEWS GENERAL Anderson, B. S ., J. W. Hunt, M. Martin, S . L. Turpen and F. H. Palmer. 1988. Marine bioassay project, third report. Protocol development ...Office of Research and Development , U. S . Environmental Protection Agency, Corvallis, OR. 60 pp. This is an acute bioassay manual designed by an EPA...test species are: 1. Purple sea urchin, Strongylocentrotus purpuratus 2. Green sea urchin, S . droebachiensis 3. Sand dollai, Dendraster excentricus

  4. Demonstration of an Integrated Compliance Model for Predicting Copper Fate and Effects in DoD Harbors

    DTIC Science & Technology

    2008-11-01

    Section 15: Purple Urchin, Strongylocentrotus purpuratus and Sand Dollar, Dendraster excentricus Larval Development Test Method. EPA/600/R- 95/136...5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ...NUMBER 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM( S ) 11. SPONSOR/MONITOR’S REPORT NUMBER( S ) 12. DISTRIBUTION

  5. Bacterial and Benthic Community Response to Inorganic and Organic Sediment Amendments

    DTIC Science & Technology

    2010-08-01

    for marine bivalve (Mytilus galloprovincialis) and echinoderm (Strongylocentrotus purpuratus ) embryonic development : Conceptual, regulatory and...AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) Space and Naval Warfare Systems...Command 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM( S ) 11

  6. Mitochondrial DNA Sequence Variation in North Atlantic Long-Finned Pilot Whales, Globicephala melas

    DTIC Science & Technology

    1994-06-01

    Strongylocentrotus purpuratus and S . droebachiensis. Evolution 44: 403-415. Rosel, P.E. (1992). Genetic population structure and systematic relationships of...reproduce and distribute copies of this thesis document in whole or in part Signale of Amho,i^ S ^*^ Joint Program in Oceanography, Massachusetts Institute...variation used in the studies described in this chapter include: 1) Genetic distance (d, p, S , or D) is a measure of the number of nucleotide

  7. Marine Ecological Risk Assessment at Naval Construction Battalion Center, Davisville, Rhode Island. Phase 1.

    DTIC Science & Technology

    1991-05-01

    on Fertilization, Survival, and Development of the Sea Urchin, Strongylocentrotus purpuratus ," in Biological Monitoring of Marine Pollutants (F... developed for each proposed study. Funding by NAVOCEANSYSCEN and EPA-ERL is subject to the U. S . Government appropriation process. No responsibility is...ecological risk assessment is developed . Exposure to and the effects of contamination are measured at both subtidal and intertidal s . %tions. A T-shaped

  8. Comparative evaluation of the DNA damage response in two Peruvian marine bivalves exposed to changes in temperature

    NASA Astrophysics Data System (ADS)

    Sotil, Giovanna; Tarazona, Juan; Alvis, Rafael; Francia, Juan C.; Shiga, Betty

    2008-03-01

    The comparison of temperature responses of two mytilids from the high ( Brachidontes purpuratus) and low ( Semimytilus algosus) intertidal zone of the Peruvian coast was carried out focusing on the production of micronucleus and nuclear abnormalities in gill tissue. Two temperatures (23 and 11°C) were evaluated, in presence of three mitomycin C concentrations as a stressor (0.02, 0.04 and 0.06 × 10-6), simulating hypothetical El Niño and La Niña conditions. Responses to extreme temperatures between both species were significantly different ( P = 0.008). Frequency of micronuclei and nuclear abnormalities in S. algosus did not differ statistically among the temperature treatments, whereas in B. purpuratus there was an observed significant decrease in nuclear abnormalities ( P = 0.012) and micronuclei frequencies ( P = 0.002) between both temperature treatments. The low frequency of micronuclei observed at high temperature and mitomycin C suggests a better efficiency to stress resistance, as occurs during El Niño events, of the species from the higher intertidal zone of B. purpuratus compared to S. algosus from the lower intertidal zone.

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

    PubMed

    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.

  10. Evolutionary analysis of the cis-regulatory region of the spicule matrix gene SM50 in strongylocentrotid sea urchins.

    PubMed

    Walters, Jenna; Binkley, Elaine; Haygood, Ralph; Romano, Laura A

    2008-03-15

    An evolutionary analysis of transcriptional regulation is essential to understanding the molecular basis of phenotypic diversity. The sea urchin is an ideal system in which to explore the functional consequence of variation in cis-regulatory sequences. We are particularly interested in the evolution of genes involved in the patterning and synthesis of its larval skeleton. This study focuses on the cis-regulatory region of SM50, which has already been characterized to a considerable extent in the purple sea urchin, Strongylocentrotus purpuratus. We have isolated the cis-regulatory region from 15 individuals of S. purpuratus as well as seven closely related species in the family Strongylocentrotidae. We have performed a variety of statistical tests and present evidence that the cis-regulatory elements upstream of the SM50 gene have been subject to positive selection along the lineage leading to S. purpuratus. In addition, we have performed electrophoretic mobility shift assays (EMSAs) and demonstrate that nucleotide substitutions within Element C affect the ability of nuclear proteins to bind to this cis-regulatory element among members of the family Strongylocentrotidae. We speculate that such changes in SM50 and other genes could accumulate to produce altered patterns of gene expression with functional consequences during skeleton formation.

  11. Dependence of sea urchin primary mesenchyme cell migration on xyloside- and sulfate-sensitive cell surface-associated components.

    PubMed

    Lane, M C; Solursh, M

    1988-05-01

    The migration of sea urchin primary mesenchyme cells (PMC) is inhibited in embryos cultured in sulfate-free seawater and in seawater containing exogenous xylosides. In the present study, primary mesenchyme cells and extra-cellular matrix have been isolated from normal and treated Lytechinus pictus and Strongylocentrotus purpuratus embryos and recombined in an in vitro migration assay to determine whether the cells or the matrix are migration defective. Normal cells were found to migrate on either normal or treated matrix, whereas sulfate-deprived and xyloside-treated PMC failed to migrate in vitro on normal and treated substrata. Migratory ability can be restored to defective cells by returning the PMC to normal seawater, or by exposing the defective cells to materials removed from the surface of normal cells with 1 M urea. The similarity of the results obtained with sulfate-deprived and xyloside-treated PMC suggested that a common molecule may be affected by the two treatments. As a first test of this possibility, xyloside-treated S. purpuratus PMC were given the urea extract prepared from sulfate-deprived S. purpuratus PMC, and this extract did not restore migratory ability. These findings indicate that PMC normally synthesize a surface-associated molecule that is involved in cell migration, and the sensitivity to exogenous xylosides and sulfate deprivation suggests that a sulfated proteoglycan may be involved in primary mesenchyme cell migration.

  12. The Hurd Peak gneiss of the Long Lake shear zone, eastern Sierra Nevada, California

    SciTech Connect

    Holland, K.S.; Reed, W.E. . Dept. of Earth and Space Sciences)

    1993-04-01

    The Hurd Peak gneiss is located within the Long Lake valley of the east-central Sierra Nevada, California. This unit is the principle orthogneiss in Hathaway's (1993) Long Lake shear zone. The rock shows porphyroclasts of plagioclase and quartz, abundant mafic enclaves, and cross-cutting field associations which suggest that the gneiss had a plutonic protolith. The gneiss varies from biotite-poor nearest the contact with the Lamarck to biotite-rich nearest Long Lake. The contact zone between the gneiss and the Lamarck pluton ranges from sharp to gradational and from migmatitic to mixed, i.e., the mixed zone being greater than 50% intermingled dikes of 10 cm or greater thickness. In places this contact is marked by a quartz-free biotite hornfels approximately 5 m thick. Based on their relative deformation, at least 3 suites of aplite dikes cross-cut the gneiss, and 5 other lithologies, including basaltic, mixed, composite, andesitic, and quartz dioritic compositions, also cross-cut the gneiss. The Rb-Sr whole rock isochron age of the Hurd Peak gneiss has been determined to be 90.2 Ma. The authors interpret this isochron to be the result of mobilization of the Rb-Sr isotopic system during intrusion of the Lamarck Granodiorite (90 Ma); this may represent a regional cooling age. The initial [sup 87]/Sr[sup 86]Sr ratio of the gneiss is 0.7098, i.e., much more evolved than the surrounding plutons which have [sup 87]Sr/[sup 86]Sr ratios near 0.706. Sr model ages indicate that the protolith of the gneiss is considerably older than 90 Ma, one such calculation suggests an age of approximately 250 Ma. Single crystals of zircon have been isolated from the gneiss for U-Pb dating, and analytical work on the zircons is presently on-going.

  13. Bacterially induced stolon settlement in the scyphopolyp of Aurelia aurita (Cnidaria, Scyphozoa)

    NASA Astrophysics Data System (ADS)

    Schmahl, G.

    1985-03-01

    Unsettled stoloniferous scyphopolyps of Aurelia aurita Lamarck were offered different substrates for settlement under defined conditions. On addition of different biogenic and abiotic substrates, a pure strain of bacteria, a species of Micrococcaceae, was observed to trigger the settlement of the stolon. The settlement reaction only takes place following direct contact with the bacteria; sterile filtrated culture medium of the same bacterial strain was not able to induce settlement. The bacteria were found to be effective on stolon settlement during the logarithmic growth phase, but not during the stationary phase.

  14. Origin of life and definition of life, from Buffon to Oparin.

    PubMed

    Tirard, Stéphane

    2010-04-01

    Many theories on origin of life at the end of the XIXth century and the beginning of the XXth, generally use conceptions of life instead of explicit definitions of life. This paper presents ideas on the origin of life as studied by Buffon (1707-1788), Lamarck (1744-1829), Darwin (1809-1882), Huxley (1825-1895), Oparin (1894-1980) and Haldane (1892-1964). We show that their conceptions on the evolution of matter and life reveal their conceptions of life rather than their definitions of life.

  15. A soul of truth in things erroneous: Popper's "amateurish" evolutionary philosophy in light of contemporary biology.

    PubMed

    Vecchi, Davide; Baravalle, Lorenzo

    2015-01-01

    This paper will critically assess Popper's evolutionary philosophy. There exists a rich literature on the topic with which we have many reservations. We believe that Popper's evolutionary philosophy should be assessed in light of the intriguing theoretical insights offered, during the last 10 years or so, by the philosophy of biology, evolutionary biology and molecular biology. We will argue that, when analysed in this manner, Popper's ideas concerning the nature of selection, Lamarckism and the theoretical limits of neo-Darwinism can be appreciated in their full biological and philosophical value.

  16. Recent biogenic phosphorite: Concretions in mollusk kidneys

    USGS Publications Warehouse

    Doyle, L.J.; Blake, N.J.; Woo, C.C.; Yevich, P.

    1978-01-01

    Phosphorite concretions have been detected in the kidneys of two widespread species ofmollusks, Mercenaria mercenaria and Argopecten irradians, which have relatively high population densities. These concretions are thefirst documentation of the direct biogenic formation of phosphorite grains. The concretions are principally amorphous calcium phosphate, which upon being heated yields an x-ray diffraction pattern which is essentially that of chlorapatite. These concretions appear to be a normal formation of the excretory process of mollusks under reproductive, environmental, or pollutant-induced stress. Biogenic production of phosphorite concretions over long periods of time and diagenetic change from amorphous to crystalline structure, coupled with secondary enrichment, may account for the formation of some marine phosphorite desposits which are not easily explained by the chemical precipitation- replacement hypothesis. Copyright ?? 1978 AAAS.

  17. The Contributions - and Collapse - of Lamarckian Heredity in Pasteurian Molecular Biology: 1. Lysogeny, 1900-1960.

    PubMed

    Loison, Laurent; Gayon, Jean; Burian, Richard M

    2017-02-01

    This article shows how Lamarckism was essential in the birth of the French school of molecular biology. We argue that the concept of inheritance of acquired characters positively shaped debates surrounding bacteriophagy and lysogeny in the Pasteurian tradition during the interwar period. During this period the typical Lamarckian account of heredity treated it as the continuation of protoplasmic physiology in daughter cells. Félix d'Hérelle applied this conception to argue that there was only one species of bacteriophage and Jules Bordet applied it to develop an account of bacteriophagy as a transmissible form of autolysis and to analyze the new phenomenon of lysogeny. In a long-standing controversy with Bordet, Eugène Wollman deployed a more morphological understanding of the inheritance of acquired characters, yielding a particulate, but still Lamarckian, account of lysogeny. We then turn to André Lwoff who, with several colleagues, completed Wollman's research program from 1949 to 1953. We examine how he gradually set aside the Lamarckian background, finally removing inheritance of acquired characters from the resulting account of bacteriophagy and lysogeny. In the conclusion, we emphasize the complex dual role of Lamarckism as it moved from an assumed explanatory framework to a challenge that the nascent molecular biology had to overcome.

  18. Is Lamarckian evolution relevant to medicine?

    PubMed Central

    2010-01-01

    Background 200 years have now passed since Darwin was born and scientists around the world are celebrating this important anniversary of the birth of an evolutionary visionary. However, the theories of his colleague Lamarck are treated with considerably less acclaim. These theories centre on the tendency for complexity to increase in organisms over time and the direct transmission of phenotypic traits from parents to offspring. Discussion Lamarckian concepts, long thought of no relevance to modern evolutionary theory, are enjoying a quiet resurgence with the increasing complexity of epigenetic theories of inheritance. There is evidence that epigenetic alterations, including DNA methylation and histone modifications, are transmitted transgenerationally, thus providing a potential mechanism for environmental influences to be passed from parents to offspring: Lamarckian evolution. Furthermore, evidence is accumulating that epigenetics plays an important role in many common medical conditions. Summary Epigenetics allows the peaceful co-existence of Darwinian and Lamarckian evolution. Further efforts should be exerted on studying the mechanisms by which this occurs so that public health measures can be undertaken to reverse or prevent epigenetic changes important in disease susceptibility. Perhaps in 2059 we will be celebrating the anniversary of both Darwin and Lamarck. PMID:20465829

  19. The prominent absence of Alfred Russel Wallace at the Darwin anniversaries in Germany in 1909, 1959 and 2009.

    PubMed

    Hossfeld, Uwe; Olsson, Lennart

    2013-12-01

    It is well known that the contribution of Alfred Russell Wallace (1823-1913) to the development of the "Darwinian" principle of natural selection has often been neglected. Here we focus on how the three anniversaries to celebrate the origin of the Darwin-Wallace theory in Germany in 1909, in 1959 in the divided country, as well as in 2009, have represented Charles Robert Darwin's and Alfred Russell Wallace's contributions. We have analyzed books and proceedings volumes related to these anniversaries, and the main result is that Wallace was almost always ignored, or only mentioned in passing. In 1909, Ernst Haeckel gave a talk in Jena, later published under the title The worldview of Darwin and Lamarck (Das Weltbild von Darwin und Lamarck), but not as the Darwin-Wallace concept. Haeckel mentions Wallace only once. In two important proceedings volumes from the 1959 anniversaries, Wallace was ignored. The only fair treatment of Wallace is given in another book, a collection of documents edited by Gerhard Heberer, for which the author selected nine key documents and reprinted excerpts (1959). Three of them were articles by Wallace, including the Sarawak- and Ternate-papers of 1855 and 1858, respectively. An analysis of the dominant themes during the celebrations of 2009 shows that none of the six topics had much to do with Wallace and his work. Thus, the tendency to exclude Alfred Russell Wallace is an international phenomenon, and largely attributable to the "Darwin industry".

  20. An introduction to epigenetics as the link between genotype and environment: a personal view.

    PubMed

    Van Soom, A; Peelman, L; Holt, W V; Fazeli, A

    2014-09-01

    Lamarck was one of the first scientists who attempted to explain evolution, and he is especially well known for formulating the concept that acquired characteristics can be transmitted to future generations and may therefore steer evolution. Although Lamarckism fell out of favour soon after the publication of Darwin's work on natural selection and evolution, the concept of transmission of acquired characteristics has recently gained renewed attention and has led to some rethinking of the standard evolutionary model. Epigenetics, or the study of heritable (mitotically and/or meiotically) changes in gene activity that are not brought about by changes in the DNA sequence, can explain some types of ill health in offspring, which have been exposed to stressors during early development, when DNA is most susceptible to such epigenetic influences. In this review, we explain briefly the history of epigenetics and we propose some examples of epigenetic and transgenerational effects demonstrated in humans and animals. Growing evidence is available that the health and phenotype of a given individual is already shaped shortly before and after the time of conception. Some evidence suggests that epigenetic markings, which have been established around conception, can also be transmitted to future generations. This knowledge can possibly be used to revolutionize animal breeding and to increase human and animal health worldwide.

  1. Supercooling capacity of Urophora affinis and U. quadrifasciata (Diptera: Tephritidae) on spotted knapweed: comparisons among plants, sites, time of season, and gall densities.

    PubMed

    Nowierski, R M.; Fitzgerald, B C.; Zeng, Z

    2001-04-01

    Larval supercooling points of Urophora affinis Frauenfeld and U. quadrifasciata (Meigen) were compared among plants, six research sites in western Montana, four fall/winter time periods, and among gall densities. These two tephritid fly species are introduced biological control agents of spotted knapweed, Centaurea maculosa Lamarck, and diffuse knapweed, Centaurea diffusa Lamarck. Few differences in larval supercooling points for U. affinis and U. quadrifasciata were found among plants, and where differences were found, they were not consistent across fall/winter time periods. Significant differences in larval supercooling points were found among sites and across fall/winter time periods. No relationship was found between larval supercooling points and site elevation. Larval supercooling points of both U. affinis and U. quadrifasciata showed no relationship with the density of Urophora galls within spotted knapweed capitula. Mean larval supercooling points of U. affinis were consistently lower than those of U. quadrifasciata across sites and fall/winter time periods. In conclusion, temporal differences in temperature over the fall/winter time periods and microclimatic differences among sites appear to be the most important abiotic factors influencing the supercooling points in U. affinis and U. quadrifasciata.

  2. Scaling of feeding biomechanics in the horn shark Heterodontus francisci: ontogenetic constraints on durophagy.

    PubMed

    Kolmann, Matthew A; Huber, Daniel R

    2009-01-01

    Organismal performance changes over ontogeny as the musculoskeletal systems underlying animal behavior grow in relative size and shape. As performance is a determinant of feeding ecology, ontogenetic changes in the former can influence the latter. The horn shark Heterodontus francisci consumes hard-shelled benthic invertebrates, which may be problematic for younger animals with lower performance capacities. Scaling of feeding biomechanics was investigated in H. francisci (n=16, 19-59cm standard length (SL)) to determine the biomechanical basis of allometric changes in feeding performance and whether this performance capacity constrains hard-prey consumption over ontogeny. Positive allometry of anterior (8-163N) and posterior (15-382N) theoretical bite force was attributed to positive allometry of cross-sectional area in two jaw adducting muscles and mechanical advantage at the posterior bite point (0.79-1.26). Mechanical advantage for anterior biting scaled isometrically (0.52). Fracture forces for purple sea urchins Strongylocentrotus purpuratus consumed by H. francisci ranged from 24 to 430N. Comparison of these fracture forces to the bite force of H. francisci suggests that H. francisci is unable to consume hard prey early in its life history, but can consume the majority of S. purpuratus by the time it reaches maximum size. Despite this constraint, positive allometry of biting performance appears to facilitate an earlier entry into the durophagous niche than would an isometric ontogenetic trajectory. The posterior gape of H. francisci is significantly smaller than the urchins capable of being crushed by its posterior bite force. Thus, the high posterior bite forces of H. francisci cannot be fully utilized while consuming prey of similar toughness and size to S. purpuratus, and its potential trophic niche is primarily determined by anterior biting capacity.

  3. Toxicity of lead and zinc to developing mussel and sea urchin embryos: critical tissue residues and effects of dissolved organic matter and salinity.

    PubMed

    Nadella, Sunita R; Tellis, Margaret; Diamond, Rachael; Smith, Scott; Bianchini, Adalto; Wood, Chris M

    2013-08-01

    Lead (Pb) EC50 values in the very sensitive early development phases (48-72h post-fertilization) of the mussels Mytilus galloprovincialis and Mytilus trossolus and sea urchin Strongylocentrotus purpuratus in 100% sea water were: M. trossolus - 45 (95% C.I.=22-72) μgL(-1); M. galloprovincialis - 63 (36-94) μgL(-1); S. purpuratus - 74 (50-101) μgL(-1). Salinity thresholds for normal development varied: M. trossolus>21ppt; M. galloprovincialis>28ppt; S. purpuratus≥30ppt. Addition of two spectroscopically distinct dissolved organic matters (DOM) from fresh water (Nordic Reservoir) and sea water (Inshore) moderately decreased the toxicity of Pb to both mussels, but not in a concentration-dependent fashion, with only an approximate doubling of EC50 over the range of 1.4-11.2mgCL(-1). Independent Pb binding capacity determinations for DOC explained the lack of a relationship between DOM concentration and toxicity. Salinity had no effect on Pb toxicity down to 21ppt in M. trossolus, and low salinity (21ppt) did not enhance the protective effect of DOC. Both DOMs increased the toxicity of Pb in developing sea urchin embryos, in contrast to mussels. Relative to Pb, the organisms were 6-9 fold less sensitive to Zn on a molar basis in 100% seawater with the following Zn EC50s: M. trossolus - 135 (103-170) μgL(-1); M. galloprovincialis - 172 (126-227) μgL(-1), S. purpuratus - 151 (129-177) μgL(-1). Nordic Reservoir and Inshore DOM (2-12mgCL(-1)) had no significant effect on Zn toxicity to mussels, in accord with voltammetry data showing an absence of any strong ligand binding for Zn by DOMs. As with Pb, DOMs increased Zn toxicity to urchin larvae. Critical Tissue Residues (CTR) based on whole body concentrations of Pb and Zn were determined for M. galloprovincialis at 48h and S. purpuratus at 72h. The median lethal CTR values (LA50s), useful parameters for development of saltwater Biotic Ligand Models (BLMs), were approximately 4-fold higher on a molar basis for Zn than

  4. A rapidly diverging EGF protein regulates species-specific signal transduction in early sea urchin development.

    PubMed

    Kamei, N; Swanson, W J; Glabe, C G

    2000-09-15

    The macromolecules mediating species-specific events during fertilization and early development and their molecular evolution are only beginning to be understood. We screened sea urchin ovary mRNA for species-specific gene products using representational differential analysis to identify unique transcripts in Strongylocentrotus franciscanus that are absent or divergent from a closely related species, S. purpuratus. One of the transcripts identified by this screening process is SfEGF-II, which contains four EGF repeats. SfEGF-II is orthologous to the previously reported genes S. purpuratus SpEGF-II and Anthocidaris crassispina AcEGF-II, encoding exogastrulation-inducing peptides (EGIP). EGF peptides derived from EGIP induce exogastrulation, a classical developmental defect, when added to embryos prior to gastrulation. The first three EGF repeats (EGF1-3) share 50 to 60% identity among the three species, but the fourth repeat (EGF4) is more divergent, displaying only 30% identity. Analysis of the sequence divergence indicates that the EGF-II genes display a relatively high nonsynonymous-to-synonymous ratio, a significant excess of radical compared to conservative amino acid substitutions, and a lack of polymorphism within SfEGF-II, indicating that these genes have been subjected to positive Darwinian selection. Recombinant EGF3 from S. franciscanus induces exogastrulation in both S. franciscanus and S. purpuratus. In contrast, recombinant EGF4 from both S. franciscanus and S. purpuratus induces exogastrula in a species-specific manner. In hybrid embryos, both species of EGF4 induce exogastrulation, suggesting that the receptor for this EGF molecule is expressed from both parental genomes during development. Both EGF3 and EGF4 induce the phosphorylation of membrane proteins of the blastula stage embryos, but EGF4 stimulates phosphorylation of proteins only in membranes prepared from homologous embryos, suggesting that it utilizes a unique pathway involving a species

  5. Synonymical and nomenclatural notes on Trachyderini (Coleoptera, Cerambycidae, Cerambycinae).

    PubMed

    Monné, Marcela L; Monné, Miguel A

    2013-01-01

    Megaderus is reinstated and attributed to Germar, 1824 and not to Rafinesque, 1815 or Dejean, 1821; Neomegaderus Monn6, 2006 is an unnecessary replacement name; Purpuricenus brasiliensis Schaufuss, 1871 is a synonym of Eriphus purpuratus Chevrolat, 1862; Panchylissus Waterhouse, 1880 is a synonym of Galissus Dupont, 1840 and G rubiventris Martins & Galileo, 2010 a synonym of G. cyaneipennis (Waterhouse, 1880), comb. nov.; Panchylissus nigriventris Lane, 1965 is transferred to Galissus; a key to the species of Galissus is provided; the female of Poecilopeplusfontanieri (Lucas, 1857) is described; Ischnotes Newman, 1840 currently in Trachyderini, Ancylocerini is transferred to incertae sedis of Cerambycinae.

  6. A Comprehensive Copper Compliance Strategy: Implementing Regulatory Guidance at Pearl Harbor Naval Shipyard & Intermediate Maintenance Facility

    DTIC Science & Technology

    2007-01-01

    seawater (N, S , C, WL, ML, EL, NMC, WLC) for four sampling events in Pearl Harbor, Hawaii. Control was expressed as percentage of normal development and...41 8. Test parameters for echinoderm embryo-larval development tests with Strongylocentrotus purpuratus (purple sea urchin) as described by the...SI O2 6 GC N S C W L ML EL NM C W LC C on tro l P er fo rm an ce (% ) 0 20 40 60 80 100 % Normal Development % Normal Survival

  7. Storm Water Toxicity Evaluation Conducted at Naval Station San Diego, Naval Submarine Base San Diego, Naval Amphibious Base Coronado, and Naval Air Station North Island

    DTIC Science & Technology

    2006-05-01

    Development PAH PCB* Chlorinated Pesticides* Cu, ZnMetals TIE TSS DOC Special Floating Bioassay Study S A M P L E T Y P E S A M P L E A N A L Y S I S ...Survival (%) Mussel Normal Development (%)NI 0 10 20 30 40 50 60 70 80 90 100 O F2 3A - S DB 4- FF O F2 3A - S DB 6- FF O F2 6- SD B6 -F F O F2 6...Strongylocentrotus purpuratus ) and Bay Mussels (Mytilus

  8. Nearshore Community Studies of Neah Bay, Washington

    DTIC Science & Technology

    1988-06-01

    purpuratus + + Urricina sp. + I *aedmI9 PtI. S . Ci-ewit . -- Mawd M4 gay x 0a f-. . . n . . . . . . t . . . . I . . . . I . . . . J 30 a AP MY JE JL SE JR...June 1988 Approved Submitted f-L" ’ Director _7LP’Y CLASSiFiCATION OF T". S PAGE Form ApprovedREPORT DOCUMENTATION PAGE OMB No 0704-0188 la REPORT...DECLASSIFICATION /DOWNGRADING SCHEDULE Unlimited 4 PERFORMING ORGANIZATION REPORT NUMBER( S ) 5. MONITORING ORGANIZATION REPORT NUMBER( S ) FRI-UW- 8811 6a NAME OF

  9. Is evolution Darwinian or/and Lamarckian?

    PubMed Central

    2009-01-01

    Background The year 2009 is the 200th anniversary of the publication of Jean-Bapteste Lamarck's Philosophie Zoologique and the 150th anniversary of Charles Darwin's On the Origin of Species. Lamarck believed that evolution is driven primarily by non-randomly acquired, beneficial phenotypic changes, in particular, those directly affected by the use of organs, which Lamarck believed to be inheritable. In contrast, Darwin assigned a greater importance to random, undirected change that provided material for natural selection. The concept The classic Lamarckian scheme appears untenable owing to the non-existence of mechanisms for direct reverse engineering of adaptive phenotypic characters acquired by an individual during its life span into the genome. However, various evolutionary phenomena that came to fore in the last few years, seem to fit a more broadly interpreted (quasi)Lamarckian paradigm. The prokaryotic CRISPR-Cas system of defense against mobile elements seems to function via a bona fide Lamarckian mechanism, namely, by integrating small segments of viral or plasmid DNA into specific loci in the host prokaryote genome and then utilizing the respective transcripts to destroy the cognate mobile element DNA (or RNA). A similar principle seems to be employed in the piRNA branch of RNA interference which is involved in defense against transposable elements in the animal germ line. Horizontal gene transfer (HGT), a dominant evolutionary process, at least, in prokaryotes, appears to be a form of (quasi)Lamarckian inheritance. The rate of HGT and the nature of acquired genes depend on the environment of the recipient organism and, in some cases, the transferred genes confer a selective advantage for growth in that environment, meeting the Lamarckian criteria. Various forms of stress-induced mutagenesis are tightly regulated and comprise a universal adaptive response to environmental stress in cellular life forms. Stress-induced mutagenesis can be construed as a quasi

  10. Immunofluorescence localization of dissociation supernatant and extracellular matrix components in Lytechinus pictus sectioned embryos. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Garciaflack, Ana Leticia

    1988-01-01

    Indirect immunofluorescence was used to localize specific extracellular components in embryos of the sea urchin Lytechinus pictus. Hyalin and S2 (a group of components found in the disaggregation supernatant from Strongylocentrotus purpuratus blastulae) were uniformly present at all stages (unfertilized up to 32 hr) except hyalin could not be detected at the 12 hour early blastula stage. Laminin was found in 16 cell, 32 cell, 6 hour, 18 hour, 24 hour, and 32 hour stages, with especially bright fluorescence at 18 hours. Collagen I was present at all stages (freshly fertilized up to 32 hour) except little was detected at 12 hours. Fibronectin was uniformly present in blastocoelar fibers stained with anto-collagen I and anti-fibronectin. These results were compared with those for S. purpuratus to produce an overview of the localization of specific extracellular matrix components during development of two species of sea urchins. The results set the stage for future studies that will examine the function of these components at the various developmental stages.

  11. A comparison of the copper sensitivity of six invertebrate species in ambient salt water of varying dissolved organic matter concentrations.

    PubMed

    Arnold, W Ray; Cotsifas, Jeffrey S; Ogle, R Scott; Depalma, Sarah G S; Smith, D Scott

    2010-02-01

    The copper sensitivity of four saltwater invertebrates (the mussel Mytilus galloprovincialis, the oyster Crassostrea virginica, the sand dollar Dendraster excentricus, and the sea urchin Strongylocentrotus purpuratus) was determined experimentally using chronic-estimator embryo-larval test procedures. The effect of sample dissolved organic matter (DOM) content on Cu bioavailability was determined for these species using commonly prescribed test procedures. Comparisons were made among these test results and test results reported previously for two other invertebrate species: the mussel Mytilus edulis and the copepod Eurytemora affinis. All six species exhibited a direct and significant relationship between the sample dissolved organic carbon (DOC; a surrogate measure of DOM) and either the dissolved Cu median lethal concentration (LC50) values or median effect concentration (EC50) values. This relationship is significant even when the DOM has different quality as evidenced by molecular fluorescence spectroscopy. Once normalized for the effects of DOM, the Cu sensitivity of these species from least to most sensitive were E. affinis < D. excitricus < C. virginica approximately S. purpuratus approximately M. edulis approximately M. galloprovincialis. This ranking of species sensitivity differs from the saltwater species sensitivity distribution proposed in 2003 by the U.S. Environmental Protection Agency. These results support the need to account for factors that modify Cu bioavailability in future saltwater Cu criteria development efforts. More specifically, Cu saltwater species sensitivity distribution data will need to be normalized by factors affecting Cu bioavailability to assure that accurate and protective criteria are subsequently developed for saltwater species and their uses.

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

    SciTech Connect

    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.

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

    PubMed

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  15. Mitochondrial DNA in the sea urchin Arbacia lixula: evolutionary inferences from nucleotide sequence analysis.

    PubMed

    De Giorgi, C; Lanave, C; Musci, M D; Saccone, C

    1991-07-01

    From the stirodont Arbacia lixula we determined the sequence of 5,127 nucleotides of mitochondrial DNA (mtDNA) encompassing 18 tRNAs, two complete coding genes, parts of three other coding genes, and part of the 12S ribosomal RNA (rRNA). The sequence confirms that the organization of mtDNA is conserved within echinoids. Furthermore, it underlines the following peculiar features of sea urchin mtDNA: the clustering of tRNAs, the short noncoding regulatory sequence, and the separation by the ND1 and ND2 genes of the two rRNA genes. Comparison with the orthologous sequences from the camarodont species Paracentrotus lividus and Strongylocentrotus purpuratus revealed that (1) echinoids have an extra piece on the amino terminus of the ND5 gene that is probably the remnant of an old leucine tRNA gene; (2) third-position codon nucleotide usage has diverged between A. lixula and the camarodont species to a significant extent, implying different directional mutational pressures; and (3) the stirodont-camarodont divergence occurred twice as long ago as did the P. lividus-S. purpuratus divergence.

  16. Multiple gene genealogies reveal asymmetrical hybridization and introgression among strongylocentrotid sea urchins.

    PubMed

    Addison, Jason A; Pogson, Grant H

    2009-03-01

    The evolution of incompatibilities between eggs and sperm is thought to play important roles in establishing and maintaining reproductive isolation among species of broadcast-spawning marine invertebrates. However, the effectiveness of gametic isolation in initiating the speciation process and/or in limiting the introgression of genes among species at later stages of divergence remains largely unknown. In the present study, we collected DNA sequence data from five loci in four species of Strongylocentrotus sea urchins (S. droebachiensis, S. pallidus, S. purpuratus, and S. franciscanus) to test whether the susceptibility of S. droebachiensis eggs to fertilization by heterospecific sperm results in gene flow between species. Despite the potential for introgression, a small but statistically significant signal of introgression was observed only between the youngest pair of sister taxa (S. pallidus and S. droebachiensis) that was strongly asymmetrical (from the former into the latter). No significant gene flow was observed for either S. purpuratus or S. franciscanus despite the ability of their sperm to readily fertilize the eggs of S. droebachiensis. Our results demonstrate that asymmetrical gamete compatibilities in strongylocentrotids can give rise to asymmetrical patterns of introgression but suggest that gamete traits alone cannot be responsible for maintaining species integrities. The genetic boundaries between strongylocentrotid urchin species in the northeast Pacific appear to be related to postzygotic isolating mechanisms that scale with divergence times and not intrinsic gametic incompatibilities per se.

  17. Iodine accumulation in sea urchin larvae is dependent on peroxide.

    PubMed

    Miller, Ashley E M; Heyland, Andreas

    2013-03-01

    Iodine has many important biological functions and its concentrations vary with the environment. Recent research has provided novel insights into iodine uptake mechanisms in marine bacteria and kelp through hydrogen peroxide-dependent diffusion (PDD). This mechanism is distinct from sodium-dependent mechanisms known from vertebrates. In vertebrates, iodine accumulates in the thyroid gland by the action of the apical iodide transporter (AIT) and the sodium/iodide symporter (NIS). Neither of these proteins has, thus far, been identified outside of the chordates, and PDD (as an iodine uptake mechanism) has never been studied in animals. Using (125)I as a marker for total iodine influx, we tested iodine uptake via sodium-dependent transport versus PDD in embryos and larvae of the sea urchin Strongylocentrotus purpuratus. We found that iodine uptake in S. purpuratus is largely independent of NIS/AIT. Instead, we found that uptake is dependent on the presence and production of hydrogen peroxide, indicating that sea urchin larvae use PDD as a mechanism for iodine acquisition. Our data, for the first time, provide conclusive evidence for this mechanism in an animal. Furthermore, our data provide preliminary evidence that sodium-dependent iodine uptake via active transporter proteins is a synapomorphy of vertebrates.

  18. Genomics and expression profiles of the Hedgehog and Notch signaling pathways in sea urchin development.

    PubMed

    Walton, Katherine D; Croce, Jenifer C; Glenn, Thomas D; Wu, Shu-Yu; McClay, David R

    2006-12-01

    The Hedgehog (Hh) and Notch signal transduction pathways control a variety of developmental processes including cell fate choice, differentiation, proliferation, patterning and boundary formation. Because many components of these pathways are conserved, it was predicted and confirmed that pathway components are largely intact in the sea urchin genome. Spatial and temporal location of these pathways in the embryo, and their function in development offer added insight into their mechanistic contributions. Accordingly, all major components of both pathways were identified and annotated in the sea urchin Strongylocentrotus purpuratus genome and the embryonic expression of key components was explored. Relationships of the pathway components, and modifiers predicted from the annotation of S. purpuratus, were compared against cnidarians, arthropods, urochordates, and vertebrates. These analyses support the prediction that the pathways are highly conserved through metazoan evolution. Further, the location of these two pathways appears to be conserved among deuterostomes, and in the case of Notch at least, display similar capacities in endomesoderm gene regulatory networks. RNA expression profiles by quantitative PCR and RNA in situ hybridization reveal that Hedgehog is produced by the endoderm beginning just prior to invagination, and signals to the secondary mesenchyme-derived tissues at least until the pluteus larva stage. RNA in situ hybridization of Notch pathway members confirms that Notch functions sequentially in the vegetal-most secondary mesenchyme cells and later in the endoderm. Functional analyses in future studies will embed these pathways into the growing knowledge of gene regulatory networks that govern early specification and morphogenesis.

  19. Developmental expression of COE across the Metazoa supports a conserved role in neuronal cell-type specification and mesodermal development.

    PubMed

    Jackson, Daniel J; Meyer, Néva P; Seaver, Elaine; Pang, Kevin; McDougall, Carmel; Moy, Vanessa N; Gordon, Kacy; Degnan, Bernard M; Martindale, Mark Q; Burke, Robert D; Peterson, Kevin J

    2010-12-01

    The transcription factor COE (collier/olfactory-1/early B cell factor) is an unusual basic helix-loop-helix transcription factor as it lacks a basic domain and is maintained as a single copy gene in the genomes of all currently analysed non-vertebrate Metazoan genomes. Given the unique features of the COE gene, its proposed ancestral role in the specification of chemosensory neurons and the wealth of functional data from vertebrates and Drosophila, the evolutionary history of the COE gene can be readily investigated. We have examined the ways in which COE expression has diversified among the Metazoa by analysing its expression from representatives of four disparate invertebrate phyla: Ctenophora (Mnemiopsis leidyi); Mollusca (Haliotis asinina); Annelida (Capitella teleta and Chaetopterus) and Echinodermata (Strongylocentrotus purpuratus). In addition, we have studied COE function with knockdown experiments in S. purpuratus, which indicate that COE is likely to be involved in repressing serotonergic cell fate in the apical ganglion of dipleurula larvae. These analyses suggest that COE has played an important role in the evolution of ectodermally derived tissues (likely primarily nervous tissues) and mesodermally derived tissues. Our results provide a broad evolutionary foundation from which further studies aimed at the functional characterisation and evolution of COE can be investigated.

  20. Select microRNAs are essential for early development in the sea urchin.

    PubMed

    Song, Jia L; Stoeckius, Marlon; Maaskola, Jonas; Friedländer, Marc; Stepicheva, Nadezda; Juliano, Celina; Lebedeva, Svetlana; Thompson, William; Rajewsky, Nikolaus; Wessel, Gary M

    2012-02-01

    microRNAs (miRNAs) are small noncoding RNAs that mediate post-transcriptional gene regulation and have emerged as essential regulators of many developmental events. The transcriptional network during early embryogenesis of the purple sea urchin, Strongylocentrotus purpuratus, is well described and can serve as an excellent model to test functional contributions of miRNAs in embryogenesis. We examined the loss of function phenotypes of major components of the miRNA biogenesis pathway. Inhibition of de novo synthesis of Drosha and Dicer in the embryo led to consistent developmental defects, a failure to gastrulate, and embryonic lethality, including changes in the steady state levels of transcription factors and signaling molecules involved in germ layer specification. We annotated and profiled small RNA expression from the ovary and several early embryonic stages by deep sequencing followed by computational analysis. miRNAs as well as a large population of putative piRNAs (piwi-interacting RNAs) had dynamic accumulation profiles through early development. Defects in morphogenesis caused by loss of Drosha could be rescued with four miRNAs. Taken together our results indicate that post-transcriptional gene regulation directed by miRNAs is functionally important for early embryogenesis and is an integral part of the early embryonic gene regulatory network in S. purpuratus.

  1. Germ line determinants are not localized early in sea urchin development, but do accumulate in the small micromere lineage.

    PubMed

    Juliano, Celina E; Voronina, Ekaterina; Stack, Christie; Aldrich, Maryanna; Cameron, Andrew R; Wessel, Gary M

    2006-12-01

    Two distinct modes of germ line determination are used throughout the animal kingdom: conditional-an inductive mechanism, and autonomous-an inheritance of maternal factors in early development. This study identifies homologs of germ line determinants in the sea urchin Strongylocentrotus purpuratus to examine its mechanism of germ line determination. A list of conserved germ-line associated genes from diverse organisms was assembled to search the S. purpuratus genome for homologs, and the expression patterns of these genes were examined during embryogenesis by whole mount in situ RNA hybridization and QPCR. Of the 14 genes tested, all transcripts accumulate uniformly during oogenesis and Sp-pumilio, Sp-tudor, Sp-MSY, and Sp-CPEB1 transcripts are also uniformly distributed during embryonic development. Sp-nanos2, Sp-seawi, and Sp-ovo transcripts, however, are enriched in the vegetal plate of the mesenchyme blastula stage and Sp-vasa, Sp-nanos2, Sp-seawi, and Sp-SoxE transcripts are localized in small micromere descendents at the tip of the archenteron during gastrulation and are then enriched in the left coelomic pouch of larvae. The results of this screen suggest that sea urchins conditionally specify their germ line, and support the hypothesis that this mechanism is the basal mode of germ line determination amongst deuterostomes. Furthermore, accumulation of germ line determinants selectively in small micromere descendents supports the hypothesis that these cells contribute to the germ line.

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

    PubMed

    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.

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

    PubMed

    Robertson, Anthony J; Coluccio, Alison; Jensen, Sarah; Rydlizky, Katarina; Coffman, James A

    2013-05-15

    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.

  4. The role of lysyl oxidase and collagen crosslinking during sea urchin development.

    PubMed

    Butler, E; Hardin, J; Benson, S

    1987-11-01

    Lysyl oxidase, the only enzyme involved in collagen crosslinking, is shown to be present in embryos of the sea urchin Strongylocentrotus purpuratus. The enzyme specific activity increases over six-fold during development, showing the greatest rise during gastrulation and prism larva formation. The enzyme is inhibited by the specific inhibitor, beta-aminoproprionitrile (BAPN). Continuous BAPN treatment of S. purpuratus and Lytechinus pictus embryos from late cleavage stages onward increases the amount of noncrosslinked collagen present in prism larvae. When BAPN is added at the 128- or 256-cell stage it causes developmental arrest at the mesenchyme blastula stage. Embryos can be maintained in the arrested state for at least 96 h and will resume normal development and morphogenesis following BAPN removal. If BAPN is added after the mesenchyme blastula stage, it has little adverse effect on development; consequently nonspecific toxic effects of the drug are unlikely. The results suggest that lysyl oxidase and collagen crosslinking play a vital role in primary mesenchyme migration, gastrulation, and morphogenesis during sea urchin development and indicate that BAPN may be very useful in studying the extracellular matrix-cell interactions at the cellular and molecular level.

  5. Elisesione, a new name for Wesenbergia Hartman, 1955, and the description of a new species (Annelida, Hesionidae)

    PubMed Central

    Salazar-Vallejo, Sergio I.

    2016-01-01

    Abstract Wesenbergia Hartman, 1955 (Annelida, Hesionidae) is both preoccupied and a junior homonym of Wesenbergia Kryger, 1943 (Hymenoptera, Pteromalidae), and must be renamed. Elisesione nom. n. is proposed as a replacement name, derived from the combination of the first name of the discoverer, Elise Wesenberg-Lund, and Hesione Savigny in Lamarck, 1818. Elisesione mezianei sp. n., is described from the Wallis and Futuna islands (southwest Pacific). A key to separate Elisesione mezianei sp. n. from its congener Elisesione problematica (Wesenberg-Lund, 1950) is included; further, the record of Elisesione problematica for Japan should be regarded as a distinct species because it has palps shorter than antennae (subequal in the type species), and shorter neurochaetal blades (7–9 times longer than wide vs 8–12 times longer than wide in the type species). PMID:27920600

  6. Of mice and men: evolution and the socialist utopia. William Morris, H.G. Wells, and George Bernard Shaw.

    PubMed

    Hale, Piers J

    2010-01-01

    During the British socialist revival of the 1880s competing theories of evolution were central to disagreements about strategy for social change. In News from Nowhere (1891), William Morris had portrayed socialism as the result of Lamarckian processes, and imagined a non-Malthusian future. H.G. Wells, an enthusiastic admirer of Morris in the early days of the movement, became disillusioned as a result of the Malthusianism he learnt from Huxley and his subsequent rejection of Lamarckism in light of Weismann's experiments on mice. This brought him into conflict with his fellow Fabian, George Bernard Shaw, who rejected neo-Darwinism in favour of a Lamarckian conception of change he called "creative evolution."

  7. Induction of stolon settlement in the scyphopolyps of Aurelia aurita (Cnidaria, Scyphozoa, Semaeostomeae) by glycolipids of marine bacteria

    NASA Astrophysics Data System (ADS)

    Schmahl, G.

    1985-06-01

    The settlement of pedal stolons of scyphopolyps of Aurelia aurita Lamarck could be induced by addition of a species of bacteria from the family Micrococcaceae. After treatment of the bacteria with several organic solvents a crude lipid extract free of bacteria could be obtained which was shown to be effective in inducing stolon settlement. Crude lipids extracted from the late logarithmic growth phase had an optimal effect on stolon attachment, in contrast to previously published experiments showing that all logarithmic phases of bacteria had the same level of effectiveness. After separation of the crude lipid extracts by thin layer chromatography and subsequent bioassay of the reeluated substances, acylgalactosidyldiglyceride and monogalactosidyldiglyceride were identified as the effective substances. Monogalactosidyldiglyceride was only found in bacteria from the medium logarithmic growth phase, whereas the former was found at all stages. The effectiveness of acylgalactosidyldiglyceride was independent of the growth phase of the extracted bacteria.

  8. [From the mechanical complexity in biology].

    PubMed

    Uribe, Libia Herrero

    2008-03-01

    From the mechanical complexity in biology. Through history, each century has brought new discoveries and beliefs that have resulted in different perspectives to study life organisms. In this essay, 1 define three periods: in the first, organisms were studied in the context of their environment, in the second, on the basis of physical and chemical laws, and on the third, systemically. My analysis starts with primitive humans, continues to Aristoteles and Newton, Lamarck and Darwin, the DNA doble helix discovery, and the beginnings of reduccionism in science. I propose that life is paradigmatical, that it obeys physical and chemical laws but cannot be explained by them I review the systemic theory, autopoiesis, discipative structures and non- linear dynamics. 1 propose that the deterministic, lineal and quantitative paradigm of nature are not the only way to study nature and invite the reader to explore the complexity paradigm.

  9. Henry H. Cheek and transformism: new light on Charles Darwin's Edinburgh background

    PubMed Central

    Jenkins, Bill

    2015-01-01

    Evidence for the transformist ideas espoused by Henry H. Cheek (1807–33), a contemporary of Charles Darwin's at the University of Edinburgh, sheds new light on the intellectual environment of Edinburgh in the late 1820s and early 1830s. Cheek was the author of several papers dealing with the transmutation of species influenced by the theories of Étienne Geoffroy Saint-Hilaire (1772–1844), Jean-Baptiste Lamarck (1744–1829) and the Comte de Buffon (1707–88). Some of these were read to student societies, others appeared in the Edinburgh Journal of Natural and Geographical Science, which Cheek edited between 1829 and 1831. His writings give us a valuable window onto some of the transformist theories that were circulating among Darwin's fellow medical students in the late 1820s, to which Darwin would have been exposed during his time in Edinburgh, and for which little other concrete evidence survives. PMID:26665300

  10. The mitochondrial genome of Pomacea maculata (Gastropoda: Ampullariidae).

    PubMed

    Yang, Qianqian; Liu, Suwen; Song, Fan; Li, Hu; Liu, Jinpeng; Liu, Guangfu; Yu, Xiaoping

    2016-07-01

    The golden apple snail, Pomacea maculata Perry, 1810 (Gastropoda: Ampullariidae) is one of the most serious invasive alien species from the native range of South America. The mitochondrial genome of P. maculata (15 516 bp) consists of 37 genes (13 protein-coding genes, two rRNAs, and 22 tRNAs) and a non-coding region with a 16 bp repeat unit. Most mitochondrial genes of P. maculata are distributed on the H-strand, except eight tRNA genes, which are encoded on the L-strand. A phylogenetic analysis showed that there was a close relationship between P. maculata and another invasive golden apple snail species, Pomacea canaliculata (Lamarck, 1822).

  11. Enzyme Inhibition by Molluscicidal Components of Myristica fragrans Houtt. in the Nervous Tissue of Snail Lymnaea acuminata

    PubMed Central

    Jaiswal, Preetee; Kumar, Pradeep; Singh, V. K.; Singh, D. K.

    2010-01-01

    This study was designed to investigate the effects of molluscicidal components of Myristica fragrans Houtt. (Myristicaceae) on certain enzymes in the nervous tissue of freshwater snail Lymnaea acuminata Lamarck (Lymnaeidae). In vivo and in vitro treatments of trimyristin and myristicin (active molluscicidal components of Myristica fragrans Houtt.) significantly inhibited the acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP/ALP) activities in the nervous tissue of Lymnaea acuminata. The inhibition kinetics of these enzymes indicates that both the trimyristin and myristicin caused competitive noncompetitive inhibition of AChE. Trimyristin caused uncompetitive and competitive/noncompetitive inhibitions of ACP and ALP, respectively whereas the myristicin caused competitive and uncompetitive inhibition of ACP and ALP, respectively. Thus results from the present study suggest that inhibition of AChE, ACP, and ALP by trimyristin and myristicin in the snail Lymnaea acuminata may be the cause of the molluscicidal activity of Myristica fragrans. PMID:21048864

  12. Making Heredity Matter: Samuel Butler's Idea of Unconscious Memory.

    PubMed

    Turbil, Cristiano

    2017-02-28

    Butler's idea of evolution was developed over the publication of four books, several articles and essays between 1863 and 1890. These publications, although never achieving the success expected by Butler, proposed a psychological elaboration of evolution (robustly enforced by Lamarck's philosophy), called 'unconscious memory'. This was strongly in contrast with the materialistic approach suggested by Darwin's natural selection. Starting with a historical introduction, this paper aspires to ascertain the logic, meaning and significance of Butler's idea of 'unconscious memory' in the post-Darwinian physiological and psychological Pan-European discussion. Particular attention is devoted to demonstrating that Butler was not only a populariser of science but also an active protagonist in the late Victorian psychological debate.

  13. The Foraminiferal Genus Orbitolina in North America

    USGS Publications Warehouse

    Douglass, Raymond Charles

    1960-01-01

    The foraminiferal genus Orbitolina has been useful as an index fossil in the Cretaceous rocks of the circumglobal equatorial belt for nearly a century. In Europe and the Near and Middle East enough work has been done on the species to allow their use for approximate correlations within the Cretaceous sedimentary rocks. The study of American specimens of Orbitolina, had been almost neglected although they were used in a rather cursory fashion for markers of the Lower Cretaceous Trinity strata. Three species had been described and assigned to Orbitolina in the United States, but the validity of each of the species had been questioned. A study of the genus Orbitolina, its type species, its morphology and the stratigraphic and geographic distribution in North America are presented in this report. Stratigraphic sections were measured throughout the area of Lower Cretaceous outcrop in Texas, New Mexico. and Arizona, and samples of Orbitolina were taken from these measured sections. Several thousand thin sections were prepared from which 8 species of Orbitolina, 7 of them new, were recognized. Orbitolina texana (Roemer) was found to be confined to the lower part of the Glen Rose limestone and its equivalents. Orbitolina, minuta n. sp. is essentially confined to the upper part of the Glen Rose limestone and its equivalents. Four of the species are known only from the Arizona and New Mexico region. The species of Orbitolina are useful stratigraphically, but all their characters-internal as well as external-must be considered. The use of thin sections for the study of Orbitolina is essential. One of the first things that had to be determined was the correct concept of the genus Orbitolina. The type species had not been determined by earlier authors, although four species had been suggested at various times. With careful study of the early literature, it became apparent that the type species is Orbitulites lenticulata Lamarck, 1816=Madreporites lenticularis Blumenbach, 1805

  14. Enzyme Inhibition by Molluscicidal Components of Myristica fragrans Houtt. in the Nervous Tissue of Snail Lymnaea acuminata.

    PubMed

    Jaiswal, Preetee; Kumar, Pradeep; Singh, V K; Singh, D K

    2010-01-01

    This study was designed to investigate the effects of molluscicidal components of Myristica fragrans Houtt. (Myristicaceae) on certain enzymes in the nervous tissue of freshwater snail Lymnaea acuminata Lamarck (Lymnaeidae). In vivo and in vitro treatments of trimyristin and myristicin (active molluscicidal components of Myristica fragrans Houtt.) significantly inhibited the acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP/ALP) activities in the nervous tissue of Lymnaea acuminata. The inhibition kinetics of these enzymes indicates that both the trimyristin and myristicin caused competitive noncompetitive inhibition of AChE. Trimyristin caused uncompetitive and competitive/noncompetitive inhibitions of ACP and ALP, respectively whereas the myristicin caused competitive and uncompetitive inhibition of ACP and ALP, respectively. Thus results from the present study suggest that inhibition of AChE, ACP, and ALP by trimyristin and myristicin in the snail Lymnaea acuminata may be the cause of the molluscicidal activity of Myristica fragrans.

  15. Cancer as a metabolic disease: implications for novel therapeutics.

    PubMed

    Seyfried, Thomas N; Flores, Roberto E; Poff, Angela M; D'Agostino, Dominic P

    2014-03-01

    Emerging evidence indicates that cancer is primarily a metabolic disease involving disturbances in energy production through respiration and fermentation. The genomic instability observed in tumor cells and all other recognized hallmarks of cancer are considered downstream epiphenomena of the initial disturbance of cellular energy metabolism. The disturbances in tumor cell energy metabolism can be linked to abnormalities in the structure and function of the mitochondria. When viewed as a mitochondrial metabolic disease, the evolutionary theory of Lamarck can better explain cancer progression than can the evolutionary theory of Darwin. Cancer growth and progression can be managed following a whole body transition from fermentable metabolites, primarily glucose and glutamine, to respiratory metabolites, primarily ketone bodies. As each individual is a unique metabolic entity, personalization of metabolic therapy as a broad-based cancer treatment strategy will require fine-tuning to match the therapy to an individual's unique physiology.

  16. Cancer as a metabolic disease: implications for novel therapeutics

    PubMed Central

    Seyfried, Thomas N.

    2014-01-01

    Emerging evidence indicates that cancer is primarily a metabolic disease involving disturbances in energy production through respiration and fermentation. The genomic instability observed in tumor cells and all other recognized hallmarks of cancer are considered downstream epiphenomena of the initial disturbance of cellular energy metabolism. The disturbances in tumor cell energy metabolism can be linked to abnormalities in the structure and function of the mitochondria. When viewed as a mitochondrial metabolic disease, the evolutionary theory of Lamarck can better explain cancer progression than can the evolutionary theory of Darwin. Cancer growth and progression can be managed following a whole body transition from fermentable metabolites, primarily glucose and glutamine, to respiratory metabolites, primarily ketone bodies. As each individual is a unique metabolic entity, personalization of metabolic therapy as a broad-based cancer treatment strategy will require fine-tuning to match the therapy to an individual’s unique physiology. PMID:24343361

  17. Sabellaria jeramae, a new species (Annelida: Polychaeta: Sabellariidae) from the shallow waters of Malaysia, with a note on the ecological traits of reefs.

    PubMed

    Nishi, Eijiroh; Matsuo, Kanako; Capa, Maria; Tomioka, Shinri; Kajihara, Hiroshi; Kupriyanova, Elena K; Polgar, Gianluca

    2015-12-07

    A new species of the genus Sabellaria Lamarck, 1818 (Annelida: Polychaeta: Sabellariidae) is described from the intertidal zone of Jeram, Selangor, Malaysia. Sabellaria jeramae n. sp. is a gregarious species that constructs large reefs several hundreds of meters long and 50-200 m wide. The new species is distinguished from other congeners by the character combination of the presence of a single kind of middle paleae with conspicuous morphology, and outer paleae with long frayed teeth. Morphological features of the species are described and compared to those of all congeneric species. We also compare the reef structure and geographical distribution of the new species to those of the members of the family Sabellariidae around the world, demonstrating the ecological traits of the reefs.

  18. Authorship of some polychaete (Annelida) names derived from the works of Renier and Savigny.

    PubMed

    Muir, Alexander I; Petersen, Mary E

    2013-01-01

    Full citations of animal specific or generic names ultimately derived from unpublished manuscripts should commemorate the work of the person who described the new species as well as the person who eventually validly published the name. We suggest that biologists should use the following authorships when citing these names: Terebella infundibulum Renier in Meneghini, 1847 (now used in the genus Myxicola); Nereis coccinea Renier in Meneghini, 1847 (now used in the genus Lumbrineris); Thalassema scutatum Renier in Ranzani, 1817 (now known as Sternaspis scutata); Polynoe Savigny in Lamarck, 1818. The case of Myxicola infundibulum is further complicated by a possible homonymy, and to avoid confusion we suggest that the name is used for the Myxicola species found in the Adriatic.

  19. The roots of phylogeny: how did Haeckel build his trees?

    PubMed

    Dayrat, Benoît

    2003-08-01

    Haeckel created much of our current vocabulary in evolutionary biology, such as the term phylogeny, which is currently used to designate trees. Assuming that Haeckel gave the same meaning to this term, one often reproduces Haeckel's trees as the first illustrations of phylogenetic trees. A detailed analysis of Haeckel's own evolutionary vocabulary and theory revealed that Haeckel's trees were genealogical trees and that Haeckel's phylogeny was a morphological concept. However, phylogeny was actually the core of Haeckel's tree reconstruction, and understanding the exact meaning Haeckel gave to phylogeny is crucial to understanding the information Haeckel wanted to convey in his famous trees. Haeckel's phylogeny was a linear series of main morphological stages along the line of descent of a given species. The phylogeny of a single species would provide a trunk around which lateral branches were added as mere ornament; the phylogeny selected for drawing a tree of a given group was considered the most complete line of progress from lower to higher forms of this group, such as the phylogeny of Man for the genealogical tree of Vertebrates. Haeckel's phylogeny was mainly inspired by the idea of the scala naturae, or scale of being. Therefore, Haeckel's genealogical trees, which were only branched on the surface, mainly represented the old idea of scale of being. Even though Haeckel decided to draw genealogical trees after reading On the Origin of Species and was called the German Darwin, he did not draw Darwinian branching diagrams. Although Haeckel always saw Lamarck, Goethe, and Darwin as the three fathers of the theory of evolution, he was mainly influenced by Lamarck and Goethe in his approach to tree reconstruction.

  20. The infauna of three widely distributed sponge species (Hexactinellida and Demospongiae) from the deep Ekström Shelf in the Weddell Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Kersken, Daniel; Göcke, Christian; Brandt, Angelika; Lejzerowicz, Franck; Schwabe, Enrico; Anna Seefeldt, Meike; Veit-Köhler, Gritta; Janussen, Dorte

    2014-10-01

    Due to their high abundance and large body size sponges have a central position in Antarctic zoobenthos, where they form the most extensive sponge grounds of the world. Though research on Antarctic benthos communities is quite established, research on sponge-associated infauna communities is scarce. We analyzed associated infauna of fifteen individuals of the sponge species Mycale (Oxymycale) acerata Kirkpatrick, 1907 (Demospongiae: Mycalina), Rossella antarctica Carter, 1872 and R. racovitzae Topsent, 1901 (both Hexactinellida: Lyssacinosida). Samples were collected from the deep Ekström Shelf at 602 m in the South-Eastern Weddell Sea, Antarctica, during the ANT XXIV-2 (SYSTCO I) expedition of RV Polarstern. The number of species, α- and β-diversity and the significantly different species composition of infauna communities related to sponge species were calculated, the latter via cluster analysis. The sponge-associated infauna consisted of five phyla: Foraminifera, Nematoda, Polychaeta, Mollusca and Arthropoda. In total 11,463 infaunal specimens were extracted and we found at least 76 associated species. Highest values of α-diversity were calculated for a sample of R. antarctica with a Shannon-Index of 1.84 and Simpson-Index of 0.72 respectively. Our results of the cluster-analysis show significant differences between infauna communities and a unique species composition for single sponge species. Polychaetes of the genus Syllis Lamarck, 1818 were numerous in M. acerata and genera like Pionosyllis Malmgren, 1867 and Cirratulus Lamarck, 1801 were numerous in R. antarctica. Individuals of the amphipod species Seba cf. dubia Schellenberg, 1926 were often found in R. antarctica and R. racovitzae while Colomastix fissilingua Schellenberg, 1926 was frequent in samples of M. acerata. Molluscs were present in M. acerata and R. antarctica but absent in R. racovitzae.

  1. William Keith Brooks and the naturalist's defense of Darwinism in the late-nineteenth century.

    PubMed

    Nash, Richard

    2015-06-01

    William Keith Brooks was an American zoologist at Johns Hopkins University from 1876 until his death in 1908. Over the course of his career, Brooks staunchly defended Darwinism, arguing for the centrality of natural selection in evolutionary theory at a time when alternative theories, such as neo-Lamarckism, grew prominent in American biology. In his book The Law of Heredity (1883), Brooks addressed problems raised by Darwin's theory of pangenesis. In modifying and developing Darwin's pangenesis, Brooks proposed a new theory of heredity that sought to avoid the pitfalls of Darwin's hypothesis. In so doing he strengthened Darwin's theory of natural selection by undermining arguments for the inheritance of acquired characteristics. In later attacks on neo-Lamarckism, Brooks consistently defended Darwin's theory of natural selection on logical grounds, continued to challenge the idea of the inheritance of acquired characteristics, and argued that natural selection best explained a wide range of adaptations. Finally, he critiqued Galton's statistical view of heredity and argued that Galton had resurrected an outmoded typological concept of species, one which Darwin and other naturalists had shown to be incorrect. Brooks's ideas resemble the "biological species concept" of the twentieth century, as developed by evolutionary biologist Ernst Mayr and others. The late-nineteenth century was not a period of total "eclipse" of Darwinism, as biologists and historians have hitherto seen it. Although the "Modern Synthesis" refers to the reconciliation of post-Mendelian genetics with evolution by natural selection, we might adjust our understanding of how the synthesis developed by seeing it as the culmination of a longer discussion that extends back to the late-nineteenth century.

  2. The origins of diversity: Darwin's conditions and epigenetic variations.

    PubMed

    Marsh, David E

    2007-01-01

    This short history of evolutionary thought during the last few centuries describes how some of our foremost thinkers have debated--and still do--the precise mechanisms at the roots of evolutionary change. Commentators frequently contradicted themselves, as well as each other. The popularity of Christian fundamentalism waned following the World Wars. Eventually the rug was pulled from beneath it--till a more recent reaction. Amidst all this babble coming from numerous towers of Babel over centuries, we failed to see Charles Darwin as the great environmentalist: who said environmental conditions, whilst working hand in glove with natural selection, constituted the more important 'law'. A bird's eye view of 18th and 19th century evolutionary thought is considered against the climate of those times (politics, industrial revolution, trade, religious expansionism, etc). Darwinism superseded Lamarckism helped by the neo-Darwinism of Weismann, higher mathematics, population genetics--the 'Modern Synthesis' of 1935--culminating in the discovery of the double helix by Watson, Crick et al, assuring us of the correctness of 'primacy of DNA theory'. Stimulation and challenge is currently fuelled by exciting nascent knowledge of epigenetic variations and Cairnsian 'adaptive mutations'. The work of Marcus Pembrey and Barry Keverne tracking human and animal variation back generationally describing how 'genomic imprinting' causes reversible heritable change from slight variations in the chromosomes of parents, grandparents, great-grandparents and parents to be. The purpose of this thesis is to put forward a new theme proposed neither by Lamarck or Darwin. We stand on the threshold of the first paradigm change for 150 years.

  3. Genetic diversity and molecular characterization of several Heliconia species in Colombia.

    PubMed

    Isaza, L; Marulanda, M L; López, A M

    2012-12-19

    Researchers have classified the Heliconia genus as a group of highly variable and diverse plants. Species and cultivars are visually differentiated primarily on the basis of the color and size of inflorescence bracts. At taxonomic level, flower type (parabolic, sigmoid, or erect) and size are taken into account. The vast morphological diversity of heliconias at intra-specific, intra-population, and varietal levels in central-west Colombia prompted the present study. We characterized the genetic variability of 67 genotypes of cultivated heliconias belonging to Heliconia caribaea Lamarck, H. bihai (L.) L., H. orthotricha L. Andersson, H. stricta Huber, H. wagneriana Petersen, and H. psittacorum L. f., as well as that of several interspecific hybrids such as H. psittacorum L. f. x H. spathocircinata Aristeguieta and H. caribaea Lamarck x H. bihai (L.) L. We also created an approximation to their phylogenetic analysis. Molecular analysis using amplified fragment length polymorphism (AFLP) markers revealed a total of 170 bands. Two large, well-defined groups resulted: the first grouped cultivars of the very closely related H. caribaea and H. bihai species with those of H. orthotricha and H. psittacorum, and the second grouped H. stricta and H. wagneriana cultivars. The lowest percentage of polymorphism was found in H. psittacorum (17.65%) and the highest was in H. stricta (55.88%). Using AFLP, phylogenetic analysis of the species studied revealed the monophyletic origin of the Heliconiaceae family, and identified the Heliconia subgenus as monophyletic while providing evidence of the polyphyletic origin of several representatives of the Stenochlamys subgenus.

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

    PubMed

    Roepke, Troy A; Snyder, Mark J; Cherr, Gary N

    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 (17beta-estradiol (E2), estrone (E1), estriol (E3), progesterone (P4) and 17alpha-ethynylestradiol (EE2)). 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 EC50 values for a reduction in normal development was as follows: TBT(L. anamesus)>OCT>TBT(S. purpuratus)>E2>EE2>DDD>BisA>P4>E1>E3. 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 E2, 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-mediated actions. Tamoxifen, a partial ER agonist, alone inhibited development at concentrations as low as 0.02 ng

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

    PubMed Central

    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

  6. Effects of past, present, and future ocean carbon dioxide concentrations on the growth and survival of larval shellfish

    PubMed Central

    Gobler, Christopher J.

    2010-01-01

    The combustion of fossil fuels has enriched levels of CO2 in the world’s oceans and decreased ocean pH. Although the continuation of these processes may alter the growth, survival, and diversity of marine organisms that synthesize CaCO3 shells, the effects of ocean acidification since the dawn of the industrial revolution are not clear. Here we present experiments that examined the effects of the ocean’s past, present, and future (21st and 22nd centuries) CO2 concentrations on the growth, survival, and condition of larvae of two species of commercially and ecologically valuable bivalve shellfish (Mercenaria mercenaria and Argopecten irradians). Larvae grown under near preindustrial CO2 concentrations (250 ppm) displayed significantly faster growth and metamorphosis as well as higher survival and lipid accumulation rates compared with individuals reared under modern day CO2 levels. Bivalves grown under near preindustrial CO2 levels displayed thicker, more robust shells than individuals grown at present CO2 concentrations, whereas bivalves exposed to CO2 levels expected later this century had shells that were malformed and eroded. These results suggest that the ocean acidification that has occurred during the past two centuries may be inhibiting the development and survival of larval shellfish and contributing to global declines of some bivalve populations. PMID:20855590

  7. Effects of Elevated Temperature and Carbon Dioxide on the Growth and Survival of Larvae and Juveniles of Three Species of Northwest Atlantic Bivalves

    PubMed Central

    Talmage, Stephanie C.; Gobler, Christopher J.

    2011-01-01

    Rising CO2 concentrations and water temperatures this century are likely to have transformative effects on many coastal marine organisms. Here, we compared the responses of two life history stages (larval, juvenile) of three species of calcifying bivalves (Mercenaria mercenaria, Crassostrea virginica, and Argopecten irradians) to temperatures (24 and 28°C) and CO2 concentrations (∼250, 390, and 750 ppm) representative of past, present, and future summer conditions in temperate estuaries. Results demonstrated that increases in temperature and CO2 each significantly depressed survival, development, growth, and lipid synthesis of M. mercenaria and A. irradians larvae and that the effects were additive. Juvenile M. mercenaria and A. irradians were negatively impacted by higher temperatures while C. virginica juveniles were not. C. virginica and A. irradians juveniles were negatively affected by higher CO2 concentrations, while M. mercenaria was not. Larvae were substantially more vulnerable to elevated CO2 than juvenile stages. These findings suggest that current and future increases in temperature and CO2 are likely to have negative consequences for coastal bivalve populations. PMID:22066018

  8. Synthesis and characterization of recombinant abductin-based proteins.

    PubMed

    Su, Renay S-C; Renner, Julie N; Liu, Julie C

    2013-12-09

    Recombinant proteins are promising tools for tissue engineering and drug delivery applications. Protein-based biomaterials have several advantages over natural and synthetic polymers, including precise control over amino acid composition and molecular weight, modular swapping of functional domains, and tunable mechanical and physical properties. In this work, we describe recombinant proteins based on abductin, an elastomeric protein that is found in the inner hinge of bivalves and functions as a coil spring to keep shells open. We illustrate, for the first time, the design, cloning, expression, and purification of a recombinant protein based on consensus abductin sequences derived from Argopecten irradians . The molecular weight of the protein was confirmed by mass spectrometry, and the protein was 94% pure. Circular dichroism studies showed that the dominant structures of abductin-based proteins were polyproline II helix structures in aqueous solution and type II β-turns in trifluoroethanol. Dynamic light scattering studies illustrated that the abductin-based proteins exhibit reversible upper critical solution temperature behavior and irreversible aggregation behavior at high temperatures. A LIVE/DEAD assay revealed that human umbilical vein endothelial cells had a viability of 98 ± 4% after being cultured for two days on the abductin-based protein. Initial cell spreading on the abductin-based protein was similar to that on bovine serum albumin. These studies thus demonstrate the potential of abductin-based proteins in tissue engineering and drug delivery applications due to the cytocompatibility and its response to temperature.

  9. Selected alternatives to conventional chlorination. Final report

    SciTech Connect

    Garey, J.F.

    1980-10-01

    This study was jointly funded by EPRI and five electric utility companies in New England (New England Power, Northeast Utilities, United Illuminating, Vermont Yankee Nuclear, and Public Service of New Hampshire). Previous investigations had identified three major areas for further study: continuous low-level chlorination, dechlorination, and condenser biofouling control. Continuous low-level chlorination, studied at two locations, one on open coastal water and the other in an industrialized estuarine area, showed that 0.1 ppM total residual oxidant (TRO) prevented attachment of the blue mussel (Mytilus edulis) to concrete surfaces. Chronic bioassays showed that 0.075 ppM TRO reduced biofouling by indigenous organisms; 0.1 ppM TRO slightly increased mortalities of the Atlantic silversides (Menidia menidia) but had no effect on the American oyster (Crassostrea virginica). Dechlorination investigations showed that threespine sticklebacks (Gasterosteus aculeatus), Atlantic silversides (Menidia menidia), larval bay scallops (Argopecten irradians), and the copepod Acartia tonsa exposed to water chlorinated to 0.5 ppM TRO for 10, 100, and 1000 seconds, followed by dechlorination with sodium thiosulfate, all suffered significant toxic effects. Condenser tube biofouling studies showed that there was a strong correlation between condenser performance and condenser tube biofouling; biofilm induction varied inversely with ambient water temperature, but orientation of the tubes had no effect on biofilm formation; and all chemicals tested (mono-, di-, and trisodium phosphate; Polident; and TRO at 0.1 ppM) reduced but did not remove biofilms.

  10. Predicting Effects of Coastal Acidification on Marine Bivalve ...

    EPA Pesticide Factsheets

    The partial pressure of carbon dioxide (pCO2) is increasing in the oceans and causing changes in seawater pH commonly described as ocean or coastal acidification. It is now well-established that, when reproduced in laboratory experiments, these increases in pCO2 can reduce survival and growth of early life stage bivalves. However, the effects that these impairments would have on whole populations of bivalves are unknown. In this study, these laboratory responses were incorporated into field-parameterized population models to assess population-level sensitivities to acidification for two northeast bivalve species with different life histories: Mercenaria mercenaria (hard clam) and Argopecten irradians (bay scallop). The resulting models permitted translation of laboratory pCO2 response functions into population-level responses to examine population sensitivity to future pCO2 changes. Preliminary results from our models indicate that if the current M. mercenaria negative population growth rate was attributed to the effects of pCO2 on early life stages, the population would decline at a rate of 50% per ten years at 420 microatmospheres (µatm) pCO2. If the current population growth rate was attributed to other additive factors (e.g., harvest, harmful algal blooms), M. mercenaria populations were predicted to decline at a rate of 50% per ten years at the preliminary estimate of 1010 µatm pCO2. The estimated population growth rate was positive for A. irradians,

  11. Testing Predictions of the Oxidative Stress Hypothesis of Aging Using a Novel Invertebrate Model of Longevity: The Giant Clam (Tridacna Derasa)

    PubMed Central

    Ungvari, Zoltan; Csiszar, Anna

    2013-01-01

    Bivalve species with exceptional longevity are newly introduced model systems in biogerontology to test evolutionarily conserved mechanisms of aging. Here, we tested predictions based on the oxidative stress hypothesis of aging using one of the tropical long-lived sessile giant clam species, the smooth giant clam (Tridacna derasa; predicted maximum life span: >100 years) and the short-lived Atlantic bay scallop (Argopecten irradians irradians; maximum life span: 2 years). The warm water–dwelling giant clams warrant attention because they challenge the commonly held view that the exceptional longevity of bivalves is a consequence of the cold water they reside in. No significant interspecific differences in production of H2O2 and in the gills, heart, or adductor muscle were observed. Protein carbonyl content in gill and muscle tissues were similar in T derasa and A i irradians. In tissues of T derasa, neither basal antioxidant capacities nor superoxide dismutase and catalase activities were consistently greater than in A i irradians. We observed a positive association between longevity and resistance to mortality induced by exposure to tert-butyl hydroperoxide (TBHP). This finding is consistent with the prediction based on the oxidative stress hypothesis of aging. The findings that in tissues of T derasa, proteasome activities are significantly increased as compared with those in tissues of A i irradians warrant further studies to test the role of enhanced protein recycling activities in longevity of bivalves. PMID:22904097

  12. Contraction increases the T(2) of muscle in fresh water but not in marine invertebrates.

    PubMed

    Meyer, R A; Prior, B M; Siles, R I; Wiseman, R W

    2001-05-01

    Previous studies suggest that the activity-induced increase in (1)H-NMR transverse relaxation time (T(2)) observed in mammalian skeletal muscles is related to an osmotic effect of intracellular metabolite accumulation. This hypothesis was tested by comparing T(2) (measured by (1)H-NMR imaging at 4.7 T) and metabolite changes (measured by (31)P-NMR spectroscopy) after stimulation in the muscles of a freshwater (crayfish, Orconectes virilis) vs two osmoconforming marine invertebrates (lobster, Homarus americanus; scallop, Argopecten concentricus). Intracellular pH significantly decreased after stimulation in the lobster tail muscle, but not in the crayfish tail or scallop phasic adductor muscles. The decrease in phosphoarginine-to-ATP ratio after stimulation was similar in the three muscles. Muscle T(2) increased from 37 to 43 ms (p < 0.02, n = 7) after stimulation in crayfish, but was unchanged in lobster muscle (32 ms, n = 7), and significantly decreased (from 40 to 36 ms, p < 0.02, n = 11) in scallop muscle. The observation that T(2) does not increase after stimulation in muscles of marine invertebrates with high natural osmolarity is consistent with the hypothesis that the T(2) increase in mammalian muscle is related to osmotically driven shifts of fluid between subcellular compartments.

  13. Kelp forest monitoring 1994 annual report. Channel Islands National Park. Final report

    SciTech Connect

    Kushner, D.; Lerma, D.; Richards, D.

    1994-12-31

    The 1994 results of the Channel Islands Natonal Park Kelp Forest Monitoring Project are described in this report. Population dynamics of 68 taxa or categories of algae, 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 quadrants, band transects, random point contacts, fish transects, video transects, size frequency measurements, artificial recruitment modules, and species list surveys. Temperature data was collected using temperature loggers deployed at each of the sixteen sites. Size frequency measurements were taken from artificial recruitment modules at ten sites. In 1994, 13 sites had giant kelp, Macrocystis pyrifera, forests, one site was dominated by the aggregating red sea cucumber, Pachythyone rubra, one site was dominated by red sea urchins, Strongylocentrotus francisanus, and another by purple sea urchins, S. purpuratus. Wasting disease was observed in sea stars and wasting syndrome was apparent in sea urchins.

  14. Ecological role of purple sea urchins.

    PubMed

    Pearse, John S

    2006-11-10

    Sea urchins are major components of marine communities. Their grazing limits algal biomass, and they are preyed upon by many predators. Purple sea urchins (Strongylocentrotus purpuratus) are among the best studied species. They live in environments that alternate between two stable states: luxuriant, species-rich kelp forests and sea urchin-dominated "barrens." The transition from one state to the other can be initiated by several factors, including the abundance of algal food, predators, storm intensities, and incidence of disease. Purple sea urchins compete with other grazers, some of which are important fishery resources (such as abalones and red sea urchins), and they are harvested for scientific research. Revelations from their genome will lead to a better understanding of how they maintain their ecological importance, and may in turn enhance their economic potential.

  15. Turbidity as a method of preparing sperm dilutions in the echinoid sperm/egg bioassay

    SciTech Connect

    Hall, T.J.; Haley, R.K.; Battan, K.J. )

    1993-11-01

    The use of turbidimeter for preparing sperm dilutions used in the echinoid sperm/egg bioassay was evaluated. Regression analyses of the relationship between sperm density and turbidity for the sea urchins Strongylocentrotus purpuratus and Strongylocentrotus droebachiensis and the sand dollar Dendraster excentricus indicated that although there were slope differences for each species, each coefficient of determination was highly significant. For Dendraster excentricus, triplicate hemacytometer counts over a range of turbidities as well as repeated preparations of a single sperm turbidity indicated similar variability for each. The use of the turbidimeter has time-saving advantages over conventional hemacytometer methods without sacrificing precision. Sperm dilutions can be prepared rapidly, minimizing seawater sperm preactivation before test initiation, and may therefore contribute to increased test precision.

  16. Colchicine-binding activity distinguishes sea urchin egg and outer doublet tubulins

    PubMed Central

    1984-01-01

    The colchicine-binding activity of tubulin has been utilized to distinguish the tubulins from two distinct microtubule systems of the same species, the sea urchin Strongylocentrotus purpuratus. We have analyzed the colchicine-binding affinities of highly purified tubulins from the unfertilized eggs and from the flagellar outer doublet microtubules by van't Hoff analysis, and have found significant differences in the free energy, enthalpy, and entropy changes characterizing the binding of colchicine to the two tubulins. The data indicate that significant chemical differences in the tubulins from the two functionally distinct microtubule systems exist, and that the differences are expressed in the native forms of the tubulins. Our findings are discussed in terms of the possibility that the colchicine- binding site may be an important regulatory site on the tubulin molecule. PMID:6539784

  17. Applied DC magnetic fields cause alterations in the time of cell divisions and developmental abnormalities in early sea urchin embryos

    SciTech Connect

    Levin, M.; Ernst, S.G.

    1997-05-01

    Most work on magnetic field effects focuses on AC fields. The present study demonstrates that exposure to medium-strength (10 mT--0.1 T) static magnetic fields can alter the early embryonic development of two species of sea urchin embryos. Batches of fertilized eggs from two species of urchin were exposed to fields produced by permanent magnets. Samples of the continuous cultures were scored for the timing of the first two cell divisions, time of hatching, and incidence of exogastrulation. It was found that static fields delay the onset of mitosis in both species by an amount dependent on the exposure timing relative to fertilization. The exposure time that caused the maximum effect differed between the two species. Thirty millitesla fields, but not 15 mT fields, caused an eightfold increase in the incidence of exogastrulation in Lytechinus pictus, whereas neither of these fields produced exogastrulation in Strongylocentrotus purpuratus.

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

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    Zimmerman, S.; Zimmerman, A.M.; Winters, W.D.; Cameron, I.L. )

    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.

  1. Expression, purification, crystallization and preliminary X-ray analysis of the olfactomedin domain from the sea urchin cell-adhesion protein amassin

    SciTech Connect

    Hillier, Brian J.; Sundaresan, Vidyasankar; Stout, C. David; Vacquier, Victor D.

    2006-01-01

    The olfactomedin (OLF) domain from the sea urchin cell-adhesion protein amassin has been crystallized. A native data set extending to 2.7 Å has been collected using an in-house X-ray source. A family of animal proteins is emerging which contain a conserved protein motif known as an olfactomedin (OLF) domain. Novel extracellular protein–protein interactions occur through this domain. The OLF-family member amassin, from the sea urchin Strongylocentrotus purpuratus, has previously been identified to mediate a rapid cell-adhesion event resulting in a large aggregation of coelomocytes, the circulating immune cells. In this work, heterologous expression and purification of the OLF domain from amassin was carried out and initial crystallization trials were performed. A native data set has been collected, extending to 2.7 Å under preliminary cryoconditions, using an in-house generator. This work leads the way to the determination of the first structure of an OLF domain.

  2. Assessment of chronic toxicity of petroleum and produced water components to marine organisms. Final technical summary

    SciTech Connect

    Cherr, G.N.; Higashi, R.M.; Shenker, J.M.

    1993-05-31

    The objectives of the report were: (1) to determine the effects of produced water exposure in early life stages of marine plants and animals, at the cellular, subcellular, and physiological levels; (2) to determine the effects of produced water exposure on reproduction in marine organisms; and (3) to develop non-invasive approaches for assessing reproductive impairment. The effects of produced water (PW) was assessed on development in three ecologically and economically important species, the purple sea urchin (Strongylocentrotus purpuratus), the giant kelp (macrocystis pyrifera), and tsahe California mussel (Mytilus califonrnianus). To determine the basis for effects of PW on these developing organisms, some fundamental studies were prerequisite. Furthermore, eggs and embryos from adults which were outplanted near the discharge were also studied. Finally, the biochemical response of embryos to PW was also defined.

  3. Spermidine is bound to a unique protein in early sea urchin embryos

    SciTech Connect

    Canellakis, Z.N.; Bondy, P.K.; Infante, A.A.

    1985-11-01

    Spermidine is rapidly taken up and becomes bound to protein during the very early hours of sea urchin embryogenesis. During the first 6 hr after fertilization of freshly obtained sea urchin eggs (Strongylocentrotus purpuratus), which are incubated in the presence of exogenous (/sup 3/H)-spermidine, up to 7% of the total cell-associated spermidine appears uniquely as spermidine bound in macromolecular form. This unique protein containing spermidine migrates as a single radioactive band in gel electrophoresis. It has a Mr of approximately equal to 30,000 and is readily distinguishable from the protein initiation factor eIF-4D, which has a Mr of 18,000, the only other identifiable protein known to date to be posttranslationally modified by polyamines.

  4. Evolutionary analysis of sea urchin mitochondrial tRNAs: folding of the molecules as suggested by the non-random occurrence of nucleotides.

    PubMed

    Giorgi, C D; Martiradonna, A; Saccone, C

    1996-08-01

    Comparative analyses of the mitochondrial tRNA sequences of the sea urchins Arbacia lixula, Paracentrotus lividus and Strongylocentrotus purpuratus revealed that conserved nucleotides may be involved in determining the typical L-shaped spatial conformation of tRNAs. These results shed light on the specific tertiary interactions that allow the folding of the atypical mitochondrial tRNAs into a functional form. A consensus mitochondrial tRNA secondary structure was derived. It shows the presence of nucleotides virtually conserved only in these organisms that represent a sort of molecular signature in sea urchins and suggests a possible physiological role. Finally, we speculate that the non-canonical structure of animal tRNAs, as well as the deviations from the universality of the genetic code, may be due to the reduction in size of the metazoan mitochondrial genome, with the concomitant acquisition of new functions by the mitochondrial tRNAs.

  5. Phase transitions in biogenic amorphous calcium carbonate

    PubMed Central

    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.

    2012-01-01

    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·H2O) → dehydrated amorphous calcium carbonate (ACC) → calcite. Unexpectedly, we find ACC·H2O-rich nanoparticles that persist after the surrounding mineral has dehydrated and crystallized. Protein matrix components occluded within the mineral must inhibit ACC·H2O 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·H2O in vitro. PMID:22492931

  6. The cloning and expression of alpha-tubulin in Monochamus alternatus.

    PubMed

    Song, L; Liu, X-X; Zhang, Y-A; Zhang, Q-W; Zhao, Z-W

    2008-09-01

    The Japanese pine sawyer Monochamus alternatus is one of the major forest pests. It damages pine directly and transfers the nematode Bursaphelenchus xylophilus to pine wood; resulting in serious economic losses around the world every year. Alpha-tubulin is one of most important proteins in most species. We cloned a ubiquitously expressed M. alternatus alpha-tubulin gene and analysed its nucleotides and protein structure; its sequence characters are consistent with what have been reported in other insects. The alignment of proteins showed that there is high homology of alpha-tubulin between M. alternatus and other species. Western blot and immunocytochemistry analyses suggested a common epitope of alpha-tubulin between M. alternatus and Strongylcentrotus purpuratus. We also expressed the protein in Escherichia coli for further functional studies.

  7. Genomic organization of Hox and ParaHox clusters in the echinoderm, Acanthaster planci.

    PubMed

    Baughman, Kenneth W; McDougall, Carmel; Cummins, Scott F; Hall, Mike; Degnan, Bernard M; Satoh, Nori; Shoguchi, Eiichi

    2014-12-01

    The organization of echinoderm Hox clusters is of interest due to the role that Hox genes play in deuterostome development and body plan organization, and the unique gene order of the Hox complex in the sea urchin Strongylocentrotus purpuratus, which has been linked to the unique development of the axial region. Here, it has been reported that the Hox and ParaHox clusters of Acanthaster planci, a corallivorous starfish found in the Pacific and Indian oceans, generally resembles the chordate and hemichordate clusters. The A. planci Hox cluster shared with sea urchins the loss of one of the medial Hox genes, even-skipped (Evx) at the anterior of the cluster, as well as organization of the posterior Hox genes.

  8. High regulatory gene use in sea urchin embryogenesis: Implications for bilaterian development and evolution.

    PubMed

    Howard-Ashby, Meredith; Materna, Stefan C; Brown, C Titus; Tu, Qiang; Oliveri, Paola; Cameron, R Andrew; Davidson, Eric H

    2006-12-01

    A global scan of transcription factor usage in the sea urchin embryo was carried out in the context of the Strongylocentrotus purpuratus genome sequencing project, and results from six individual studies are here considered. Transcript prevalence data were obtained for over 280 regulatory genes encoding sequence-specific transcription factors of every known family, but excluding genes encoding zinc finger proteins. This is a statistically inclusive proxy for the total "regulome" of the sea urchin genome. Close to 80% of the regulome is expressed at significant levels by the late gastrula stage. Most regulatory genes must be used repeatedly for different functions as development progresses. An evolutionary implication is that animal complexity at the stage when the regulome first evolved was far simpler than even the last common bilaterian ancestor, and is thus of deep antiquity.

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

    PubMed

    Garfield, David A; Runcie, Daniel E; Babbitt, Courtney C; Haygood, Ralph; Nielsen, William J; Wray, Gregory A

    2013-10-01

    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.

  10. Diversity of olfactomedin proteins in the sea urchin.

    PubMed

    Hillier, Brian J; Moy, Gary W; Vacquier, Victor D

    2007-06-01

    Olfactomedin (OLF) domain proteins maintain extracellular protein-protein interactions in diverse phyla. Only one OLF family member, amassin-1, has been described from the sea urchin Strongylocentrotus purpuratus, a basal invertebrate deuterostome. Amassin-1 mediates intercellular adhesion of coelomocytes (immunocytes). Here we describe the protein structural features of four additional OLF proteins, the total for the genome being five. Phylogenetically, four of these proteins (the amassins) form a subgroup among previously identified OLF proteins. The fifth OLF protein is within the colmedin subfamily and contains a type II transmembrane domain, collagen repeats, and an OLF domain. Sea urchin OLF proteins represent an intermediate diversification between protostomes and vertebrates. Transcripts of all five OLF family members are in coelomocytes and adult radial nerve tissue. Transcripts for some OLF proteins increase during late larval stages. Transcript levels for amassin-1 increase 1,000,000-fold, coinciding with formation of the adult urchin rudiment within the larval body.

  11. Sea urchin collagen evolutionarily homologous to vertebrate pro-alpha 2(I) collagen.

    PubMed

    Exposito, J Y; D'Alessio, M; Solursh, M; Ramirez, F

    1992-08-05

    We isolated several overlapping cDNA clones covering the 4242 nucleotides of a Strongylocentrotus purpuratus transcript that codes for a fibrillar procollagen chain. The sea urchin polypeptide includes a 124-amino acid long amino pre-propeptide, a 1064-amino acid alpha-chain inclusive of 338 uninterrupted Gly-X-Y repeats, and a 226-residue carboxyl-propeptide. The distribution of the highly conserved cysteines within the last domain together with the structural configuration of the amino-propeptide and the organization of the corresponding coding region, strongly suggest that the sea urchin gene is evolutionarily related to the vertebrate pro-alpha 2(I) collagen. This work, therefore, represents the first report of the complete primary structure of an invertebrate fibrillar procollagen chain. It also provides a new insight into the evolution of the amino-propeptide, the most divergent among the major protein domains of fibrillar procollagen chains.

  12. SpBase: the sea urchin genome database and web site.

    PubMed

    Cameron, R Andrew; Samanta, Manoj; Yuan, Autumn; He, Dong; Davidson, Eric

    2009-01-01

    SpBase is a system of databases focused on the genomic information from sea urchins and related echinoderms. It is exposed to the public through a web site served with open source software (http://spbase.org/). The enterprise was undertaken to provide an easily used collection of information to directly support experimental work on these useful research models in cell and developmental biology. The information served from the databases emerges from the draft genomic sequence of the purple sea urchin, Strongylocentrotus purpuratus and includes sequence data and genomic resource descriptions for other members of the echinoderm clade which in total span 540 million years of evolutionary time. This version of the system contains two assemblies of the purple sea urchin genome, associated expressed sequences, gene annotations and accessory resources. Search mechanisms for the sequences and the gene annotations are provided. Because the system is maintained along with the Sea Urchin Genome resource, a database of sequenced clones is also provided.

  13. Localization of tektin filaments in microtubules of sea urchin sperm flagella by immunoelectron microscopy

    PubMed Central

    1985-01-01

    Extraction of doublet microtubules from the sperm flagella of the sea urchin Strongylocentrotus purpuratus with sarkosyl (0.5%)-urea (2.5 M) yields a highly pure preparation of "tektin" filaments that we have previously shown to resemble intermediate filament proteins. They form filaments 2-3 nm in diameter as seen by negative stain electron microscopy and are composed of approximately equal amounts of three polypeptide bands with apparent molecular weights of 47,000, 51,000, and 55,000, as determined by SDS PAGE. We prepared antibodies to this set of proteins to localize them in the doublet microtubules of S. purpuratus and other species. Tektins and tubulin were antigenically distinct when tested by immunoblotting with affinity-purified antitektin and antitubulin antibodies. Fixed sperm or axonemes from several different species of sea urchin showed immunofluorescent staining with antitektin antibodies. We also used antibodies coupled to gold spheres to localize the proteins by electron microscopy. Whereas a monoclonal antitubulin (Kilmartin, J.V., B. Wright, and C. Milstein, 1982, J. Cell Biol. 93:576-582) decorates intact microtubules along their lengths, antitektins labeled only the ends of intact microtubules and sarkosyl-insoluble ribbons. However, if microtubules and ribbons attached to electron microscope grids were first extracted with sarkosyl-urea, the tektin filaments that remain were decorated by antitektin antibodies throughout their length. These results suggest that tektins form integral filaments of flagellar microtubule walls, whose antigenic sites are normally masked, perhaps by the presence of tubulin around them. PMID:3880749

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

    PubMed Central

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

    2016-01-01

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

  15. A mechanistic model to study the thermal ecology of a southeastern pacific dominant intertidal mussel and implications for climate change.

    PubMed

    Finke, G R; Bozinovic, F; Navarrete, S A

    2009-01-01

    Developing mechanistic models to predict an organism's body temperature facilitates the study of physiological stresses caused by extreme climatic conditions the species might have faced in the past or making predictions about changes to come in the near future. Because the models combine empirical observation of different climatic variables with essential morphological attributes of the species, it is possible to examine specific aspects of predicted climatic changes. Here, we develop a model for the competitively dominant intertidal mussel Perumytilus purpuratus that estimates body temperature on the basis of meteorological and tidal data with an average difference (+/-SE) of 0.410 degrees +/- 0.0315 degrees C in comparison with a field-deployed temperature logger. Modeled body temperatures of P. purpuratus in central Chile regularly exceeded 30 degrees C in summer months, and values as high as 38 degrees C were found. These results suggest that the temperatures reached by mussels in the intertidal zone in central Chile are not sufficiently high to induce significant mortality on adults of this species; however, because body temperatures >40 degrees C can be lethal for this species, sublethal effects on physiological performance warrant further investigation. Body temperatures of mussels increased sigmoidally with increasing tidal height. Body temperatures of individuals from approximately 70% of the tidal range leveled off and did not increase any further with increasing tidal height. Finally, body size played an important role in determining body temperature. A hypothetical 5-cm-long mussel (only 1 cm longer than mussels found in nature) did reach potentially lethal body temperatures, suggesting that the biophysical environment may play a role in limiting the size of this small species.

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

    SciTech Connect

    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.

  17. The GTP-binding protein RhoA localizes to the cortical granules of Strongylocentrotus purpuratas sea urchin egg and is secreted during fertilization.

    PubMed

    Cuéllar-Mata, P; Martínez-Cadena, G; López-Godínez, J; Obregón, A; García-Soto, J

    2000-02-01

    The sea urchin egg has thousands of secretory vesicles known as cortical granules. Upon fertilization, these vesicles undergo a Ca2+-dependent exocytosis. G-protein-linked mechanisms may take place during the egg activation. In somatic cells from mammals, GTP-binding proteins of the Rho family regulate a number of cellular processes, including organization of the actin cytoskeleton. We report here that a crude membrane fraction from homogenates of Strongylocentrotus purpuratus sea urchin eggs, incubated with C3 (which ADP-ribosylates specifically Rho proteins) and [32P]NAD, displayed an [32P]ADP-ribosylated protein of 25 kDa that had the following characteristics: i) identical electrophoretic mobility in SDS-PAGE gels as the [32P]ADP-ribosylated Rho from sea urchin sperm; ii) identical mobility in isoelectro focusing gels as human RhoA; iii) positive cross-reactivity by immunoblotting with an antibody against mammalian RhoA. Thus, unfertilized S. purpuratus eggs contain a mammalian RhoA-like protein. Immunocytochemical analyses indicated that RhoA was localized preferentially to the cortical granules; this was confirmed by experiments of [32P]ADP-ribosylation with C3 in isolated cortical granules. Rho was secreted and retained in the fertilization membrane after insemination or activation with A23187. It was observed that the Rho protein present in the sea urchin sperm acrosome was also secreted during the exocytotic acrosome reaction. Thus, Rho could participate in those processes related to the cortical granules, i.e., in the Ca2+-regulated exocytosis or actin reorganization that accompany the egg activation.

  18. Identification, Modeling and Ligand Affinity of Early Deuterostome CYP51s, and Functional Characterization of Recombinant Zebrafish Sterol 14α-Demethylase

    PubMed Central

    Morrison, Ann Michelle Stanley; Goldstone, Jared V.; Lamb, David C.; Kubota, Akira; Lemaire, Benjamin; Stegeman, John. J.

    2014-01-01

    Background Sterol 14α-demethylase (cytochrome P450 51, CYP51, P45014DM) is a microsomal enzyme that in eukaryotes catalyzes formation of sterols essential for cell membrane function and as precursors in biosynthesis of steroid hormones. Functional properties of CYP51s are unknown in non-mammalian deuterostomes. Methods PCR-cloning and sequencing and computational analyses (homology modeling and docking) addressed CYP51 in zebrafish Danio rerio, the reef fish sergeant major Abudefduf saxatilis, and the sea urchin Strongylocentrotus purpuratus. Following N-terminal amino acid modification, zebrafish CYP51 was expressed in Escherichia coli, and lanosterol 14α-demethylase activity and azole inhibition of CYP51 activity were characterized using GC/MS. Results Molecular phylogeny positioned S. purpuratus CYP51 at the base of the deuterostome clade. In zebrafish, CYP51 is expressed in all organs examined, most strongly in intestine. The recombinant protein bound lanosterol and catalyzed 14α-demethylase activity, at 3.2 nmol/min/nmol CYP51. The binding of azoles to zebrafish CYP51 gave KS (dissociation constant) values of 0.26 μM for ketoconazole and 0.64 μM for propiconazole. Displacement of carbon monoxide also indicated zebrafish CYP51 has greater affinity for ketoconazole. Docking to homology models showed that lanosterol docks in fish and sea urchin CYP51s with an orientation essentially the same as in mammalian CYP51. Docking of ketoconazole indicates it would inhibit fish and sea urchin CYP51s. Conclusions Biochemical and computational analyses are consistent with lanosterol being a substrate for early deuterostome CYP51s. General Significance The results expand the phylogenetic view of animal CYP51, with evolutionary, environmental and therapeutic implications. PMID:24361620

  19. Whole-genome positive selection and habitat-driven evolution in a shallow and a deep-sea urchin.

    PubMed

    Oliver, Thomas A; Garfield, David A; Manier, Mollie K; Haygood, Ralph; Wray, Gregory A; Palumbi, Stephen R

    2010-01-01

    Comparisons of genomic sequence between divergent species can provide insight into the action of natural selection across many distinct classes of proteins. Here, we examine the extent of positive selection as a function of tissue-specific and stage-specific gene expression in two closely-related sea urchins, the shallow-water Strongylocentrotus purpuratus and the deep-sea Allocentrotus fragilis, which have diverged greatly in their adult but not larval habitats. Genes that are expressed specifically in adult somatic tissue have significantly higher dN/dS ratios than the genome-wide average, whereas those in larvae are indistinguishable from the genome-wide average. Testis-specific genes have the highest dN/dS values, whereas ovary-specific have the lowest. Branch-site models involving the outgroup S. franciscanus indicate greater selection (ω(FG)) along the A. fragilis branch than along the S. purpuratus branch. The A. fragilis branch also shows a higher proportion of genes under positive selection, including those involved in skeletal development, endocytosis, and sulfur metabolism. Both lineages are approximately equal in enrichment for positive selection of genes involved in immunity, development, and cell-cell communication. The branch-site models further suggest that adult-specific genes have experienced greater positive selection than those expressed in larvae and that ovary-specific genes are more conserved (i.e., experienced greater negative selection) than those expressed specifically in adult somatic tissues and testis. Our results chart the patterns of protein change that have occurred after habitat divergence in these two species and show that the developmental or functional context in which a gene acts can play an important role in how divergent species adapt to new environments.

  20. Sediment toxicity test results for the Urban Waters Study 2010, Bellingham Bay, Washington

    USGS Publications Warehouse

    Biedenbach, James M.

    2011-01-01

    The Washington Department of Ecology annually determines the quality of recently deposited sediments in Puget Sound as a part of Ecology's Urban Waters Initiative. The annual sediment quality studies use the Sediment Quality Triad (SQT) approach, thus relying on measures of chemical contamination, toxicity, and benthic in-faunal effects (Chapman, 1990). Since 2002, the studies followed a rotating sampling scheme, each year sampling a different region of the greater Puget Sound Basin. During the annual studies, samples are collected in locations selected with a stratified-random design, patterned after the designs previously used in baseline surveys completed during 1997-1999 (Long and others, 2003; Wilson and Partridge, 2007). Sediment samples were collected by personnel from the Washington Department of Ecology, in June of 2010 and shipped to the U. S. Geological Survey (USGS) laboratory in Corpus Christi, Texas (not shown), where the tests were performed. Sediment pore water was extracted with a pneumatic apparatus and was stored frozen. Just before testing, water-quality measurements were made and salinity adjusted, if necessary. Tests were performed on a dilution series of each sample consisting of 100-, 50-, and 25-percent pore-water concentrations. The specific objectives of this study were to: * Extract sediment pore water from a total of 30 sediment samples from the Bellingham Bay, Washington area within a day of receipt of the samples. * Measure water-quality parameters (salinity, dissolved oxygen, pH, sulfide, and ammonia) of thawed pore-water samples before testing and adjust salinity, temperature and dissolved oxygen, if necessary, to obtain optimal ranges for the test species. * Conduct the fertilization toxicity test with pore water using sea urchin (Stronylocentrotus purpuratus) (S. purpuratus) gametes. * Perform quality control assays with reference pore water, dilution blanks and a positive control dilution series with sodium dodecyl sulfate (SDS

  1. Molecular cloning of hsf1 and hsbp1 cDNAs, and the expression of hsf1, hsbp1 and hsp70 under heat stress in the sea cucumber Apostichopus japonicus.

    PubMed

    Xu, Dongxue; Sun, Lina; Liu, Shilin; Zhang, Libin; Yang, Hongsheng

    2016-08-01

    The heat shock response (HSR) is known for the elevated synthesis of heat shock proteins (HSPs) under heat stress, which is mediated primarily by heat shock factor 1 (HSF1). Heat shock factor binding protein 1 (HSBP1) and feedback control of heat shock protein 70 (HSP70) are major regulators of the activity of HSF1. We obtained full-length cDNA of genes hsf1 and hsbp1 in the sea cucumber Apostichopus japonicus, which are the second available for echinoderm (after Strongylocentrotus purpuratus), and the first available for holothurian. The full-length cDNA of hsf1 was 2208bp, containing a 1326bp open reading frame encoding 441 amino acids. The full-length cDNA of hsbp1 was 2850bp, containing a 225bp open reading frame encoding 74 amino acids. The similarities of A. japonicus HSF1 with other species are low, and much higher similarity identities of A. japonicus HSBP1 were shared. Phylogenetic trees showed that A. japonicus HSF1 and HSBP1 were clustered with sequences from S. purpuratus, and fell into distinct clades with sequences from mollusca, arthropoda and vertebrata. Analysis by real-time PCR showed hsf1 and hsbp1 mRNA was expressed constitutively in all tissues examined. The expression of hsf1, hsbp1 and hsp70 in the intestine at 26°C was time-dependent. The results of this study might provide new insights into the regulation of heat shock response in this species.

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

    PubMed

    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.

  3. Divergent patterns of neural development in larval echinoids and asteroids.

    PubMed

    Nakajima, Yoko; Kaneko, Hiroyuki; Murray, Greg; Burke, Robert D

    2004-01-01

    The development and organization of the nervous systems of echinoderm larvae are incompletely described. We describe the development and organization of the larval nervous systems of Strongylocentrotus purpuratus and Asterina pectinifera using a novel antibody, 1E11, that appears to be neuron specific. In the early pluteus, the antibody reveals all known neural structures: apical ganglion, oral ganglia, lateral ganglia, and an array of neurons and neurites in the ciliary band, the esophagus, and the intestine. The antibody also reveals several novel features, such as neurites that extend to the posterior end of the larva and additional neurons in the apical ganglion. Similarly, in asteroid larvae the antibody binds to all known neural structures and identifies novel features, including large numbers of neurons in the ciliary bands, a network of neurites under the oral epidermis, cell bodies in the esophagus, and a network of neurites in the intestine. The 1E11 antigen is expressed during gastrulation and can be used to trace the ontogenies of the nervous systems. In S. purpuratus, a small number of neuroblasts arise in the oral ectoderm in late gastrulae. The cells are adjacent to the presumptive ciliary bands, where they project neurites with growth cone-like endings that interconnect the neurons. In A. pectinifera, a large number of neuroblasts appear scattered throughout the ectoderm of gastrulae. The cells aggregate in the developing ciliary bands and then project neurites under the oral epidermis. Although there are several shared features of the larval nervous systems of echinoids and asteroids, the patterns of development reveal fundamental differences in neural ontogeny.

  4. Conservation of Endo16 expression in sea urchins despite evolutionary divergence in both cis and trans-acting components of transcriptional regulation

    NASA Technical Reports Server (NTRS)

    Romano, Laura A.; Wray, Gregory A.

    2003-01-01

    Evolutionary changes in transcriptional regulation undoubtedly play an important role in creating morphological diversity. However, there is little information about the evolutionary dynamics of cis-regulatory sequences. This study examines the functional consequence of evolutionary changes in the Endo16 promoter of sea urchins. The Endo16 gene encodes a large extracellular protein that is expressed in the endoderm and may play a role in cell adhesion. Its promoter has been characterized in exceptional detail in the purple sea urchin, Strongylocentrotus purpuratus. We have characterized the structure and function of the Endo16 promoter from a second sea urchin species, Lytechinus variegatus. The Endo16 promoter sequences have evolved in a strongly mosaic manner since these species diverged approximately 35 million years ago: the most proximal region (module A) is conserved, but the remaining modules (B-G) are unalignable. Despite extensive divergence in promoter sequences, the pattern of Endo16 transcription is largely conserved during embryonic and larval development. Transient expression assays demonstrate that 2.2 kb of upstream sequence in either species is sufficient to drive GFP reporter expression that correctly mimics this pattern of Endo16 transcription. Reciprocal cross-species transient expression assays imply that changes have also evolved in the set of transcription factors that interact with the Endo16 promoter. Taken together, these results suggest that stabilizing selection on the transcriptional output may have operated to maintain a similar pattern of Endo16 expression in S. purpuratus and L. variegatus, despite dramatic divergence in promoter sequence and mechanisms of transcriptional regulation.

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

    PubMed

    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

  6. Some biological reflections on the concept of life.

    PubMed

    Pennazio, Sergio

    2010-01-01

    Life is the natural phenomenon that has always aroused the largest interest of philosophers, theologians and scientists, on which a new science--biology--was founded two century ago just for throwing light on its mechanisms. As the pre-Hellenic culture was not able to separate distinctly philosophy from science, life was interpreted as a spurious flurry of the activity of Nature, in which religion, magic and science were interlaced in an intricate way. The Hippocratic medicine constituted the first attempt to focus attention on life by collecting some biological knowledge in order to maintain man's health. All the subsequent physiologists (from the Hellenic to the Latin period) benefited from the precepts of the Corpus Hippocraticum as long as the Christian religion imposed its theological rules that favoured the question relative to soul ever more closely interlaced with the physiology of body. The concept of life became therefore subjected to a number of opposite theories with strong prevalence of metaphysical conjectures until the 19th century but, in spite of this imposition, splendid successes were achieved by physiologists and naturalists such as Harvey, Descartes, Haller, Malpighi, Spallanzani, Wolff, and others, who laid the foundation of a biology that has Lamarck as promoter. The importance of Lamarck's biology came from the release from metaphysics with the introduction of physical and structural concepts which permeated the experimental biology to come. Three main events characterised the biology of the 19th century: i) the interplay of the new chemistry with biology, ii) the cell theory, iii) the concept of metabolism. These events led biology to the 20th century, the era of biochemistry and molecular genetics. The discoveries relative to metabolism characterised the first half of this century, while the second half was witness to the internal mechanisms regulating the life of cells, perhaps the most advanced success of the biology of all time. Today

  7. Hypoxia and acidification have additive and synergistic negative effects on the growth, survival, and metamorphosis of early life stage bivalves.

    PubMed

    Gobler, Christopher J; DePasquale, Elizabeth L; Griffith, Andrew W; Baumann, Hannes

    2014-01-01

    Low oxygen zones in coastal and open ocean ecosystems have expanded in recent decades, a trend that will accelerate with climatic warming. There is growing recognition that low oxygen regions of the ocean are also acidified, a condition that will intensify with rising levels of atmospheric CO2. Presently, however, the concurrent effects of low oxygen and acidification on marine organisms are largely unknown, as most prior studies of marine hypoxia have not considered pH levels. We experimentally assessed the consequences of hypoxic and acidified water for early life stage bivalves (bay scallops, Argopecten irradians, and hard clams, Mercenaria mercenaria), marine organisms of significant economic and ecological value and sensitive to climate change. In larval scallops, experimental and naturally-occurring acidification (pH, total scale  = 7.4-7.6) reduced survivorship (by >50%), low oxygen (30-50 µM) inhibited growth and metamorphosis (by >50%), and the two stressors combined produced additively negative outcomes. In early life stage clams, however, hypoxic waters led to 30% higher mortality, while acidified waters significantly reduced growth (by 60%). Later stage clams were resistant to hypoxia or acidification separately but experienced significantly (40%) reduced growth rates when exposed to both conditions simultaneously. Collectively, these findings demonstrate that the consequences of low oxygen and acidification for early life stage bivalves, and likely other marine organisms, are more severe than would be predicted by either individual stressor and thus must be considered together when assessing how ocean animals respond to these conditions both today and under future climate change scenarios.

  8. Hypoxia and Acidification Have Additive and Synergistic Negative Effects on the Growth, Survival, and Metamorphosis of Early Life Stage Bivalves

    PubMed Central

    Gobler, Christopher J.; DePasquale, Elizabeth L.; Griffith, Andrew W.; Baumann, Hannes

    2014-01-01

    Low oxygen zones in coastal and open ocean ecosystems have expanded in recent decades, a trend that will accelerate with climatic warming. There is growing recognition that low oxygen regions of the ocean are also acidified, a condition that will intensify with rising levels of atmospheric CO2. Presently, however, the concurrent effects of low oxygen and acidification on marine organisms are largely unknown, as most prior studies of marine hypoxia have not considered pH levels. We experimentally assessed the consequences of hypoxic and acidified water for early life stage bivalves (bay scallops, Argopecten irradians, and hard clams, Mercenaria mercenaria), marine organisms of significant economic and ecological value and sensitive to climate change. In larval scallops, experimental and naturally-occurring acidification (pH, total scale  = 7.4–7.6) reduced survivorship (by >50%), low oxygen (30–50 µM) inhibited growth and metamorphosis (by >50%), and the two stressors combined produced additively negative outcomes. In early life stage clams, however, hypoxic waters led to 30% higher mortality, while acidified waters significantly reduced growth (by 60%). Later stage clams were resistant to hypoxia or acidification separately but experienced significantly (40%) reduced growth rates when exposed to both conditions simultaneously. Collectively, these findings demonstrate that the consequences of low oxygen and acidification for early life stage bivalves, and likely other marine organisms, are more severe than would be predicted by either individual stressor and thus must be considered together when assessing how ocean animals respond to these conditions both today and under future climate change scenarios. PMID:24416169

  9. Anatomical mercury speciation in bay scallops by thio-bearing chelating resin concentration and GC-electron capture detector determination.

    PubMed

    Zhang, Qihua; Yang, Guipeng

    2014-01-01

    The highly toxic methyl-, ethyl- and phenylmercury species that may exist in the three main anatomical parts - the adductor muscle, the mantle and the visceral mass - of bay scallops (Argopecten irradias) were quantitatively released by cupric chloride, zinc acetate, sodium chloride and hydrochloric acid (HCl) under ultrasonic extraction. After centrifugation, the mercury species in the supernatant were concentrated by thio (SH)-bearing chelating resins, eluted with HClO4 and HCl and extracted with toluene. Separation was achieved by capillary GC equipped with programmed temperatures, a constant nitrogen flow and detected by a micro-electron capture detector (μECD). Under optimised conditions, the LODs for methyl-, ethyl- and phenylmercury in bay scallop samples were 1.1, 0.65 and 0.80 ng g(-1), respectively. The maximum RSD for three replicate determinations of methyl-, ethyl- and phenylmercury in bay scallop samples were 13.7%, 14.0% and 11.2%, respectively. In the concentration range of 4-200 ng g(-1) in bay scallop samples, the calibration graphs were linear with correlation coefficients not less than 0.997. Recoveries for spiked samples were in the range of 92.7-103.5% (methylmercury), 87.5-108.3% (ethylmercury) and 91.6-106.0% (phenylmercury), respectively. The method was verified by the determination of methylmercury in a CRM GBW10029 (Total Mercury and Methyl Mercury in Fish Tissue), with results in good agreement with the certified values. Methylmercury - the only existing species in bay scallops - was successfully determined by the method.

  10. Spectral sensitivity of the concave mirror eyes of scallops: potential influences of habitat, self-screening and longitudinal chromatic aberration.

    PubMed

    Speiser, Daniel I; Loew, Ellis R; Johnsen, Sönke

    2011-02-01

    Scallop eyes contain two retinas, one proximal and one distal. Molecular evidence suggests that each retina expresses a different visual pigment. To test whether these retinas have different spectral sensitivities, we used microspectrophotometry to measure the absorption spectra of photoreceptors from the eyes of two different scallop species. Photoreceptors from the proximal and distal retinas of the sea scallop Placopecten magellanicus had absorption peak wavelengths (λ(max)) of 488 ± 1 nm (mean ± s.e.m.; N=20) and 513 ± 3 nm (N=26), respectively. Photoreceptors from the corresponding retinas of the bay scallop Argopecten irradians had λ(max) values of 506 ± 1 nm (N=21) and 535 ± 3 nm (N=14). Assuming that the proximal and distal receptors had equal absorption coefficients (k(D)=0.0067 microm(-1)), we found that self-screening within the scallop eye caused the proximal and distal receptors in P. magellanicus to have peak absorption at 490 and 520 nm, respectively, and the corresponding receptors in A. irradians to have peak absorption at 504 and 549 nm. We conclude that environment may influence the λ(max) of scallop visual pigments: P. magellanicus, generally found in blue oceanic water, has visual pigments that are maximally sensitive to shorter wavelengths than those found in A. irradians, which lives in greener inshore water. Scallop distal retinas may be sensitive to longer wavelengths of light than scallop proximal retinas to correct for either self-screening by the retinas or longitudinal chromatic aberration of the lens.

  11. Physiological response and resilience of early life-stage Eastern oysters (Crassostrea virginica) to past, present and future ocean acidification

    PubMed Central

    Gobler, Christopher J.; Talmage, Stephanie C.

    2014-01-01

    The Eastern oyster, Crassostrea virginica (Gmelin, 1791), is the second most valuable bivalve fishery in the USA and is sensitive to high levels of partial pressure of CO2 (pCO2). Here we present experiments that comprehensively examined how the ocean's past, present and projected (21st and 22nd centuries) CO2 concentrations impact the growth and physiology of larval stages of C. virginica. Crassostrea virginica larvae grown in present-day pCO2 concentrations (380 μatm) displayed higher growth and survival than individuals grown at both lower (250 μatm) and higher pCO2 levels (750 and 1500 μatm). Crassostrea virginica larvae manifested calcification rates, sizes, shell thicknesses, metamorphosis, RNA:DNA ratios and lipid contents that paralleled trends in survival, with maximal values for larvae grown at 380 μatm pCO2 and reduced performance in higher and lower pCO2 levels. While some physiological differences among oysters could be attributed to CO2-induced changes in size or calcification rates, the RNA:DNA ratios at ambient pCO2 levels were elevated, independent of these factors. Likewise, the lipid contents of individuals exposed to high pCO2 levels were depressed even when differences in calcification rates were considered. These findings reveal the cascading, interdependent impact that high CO2 can have on oyster physiology. Crassostrea virginica larvae are significantly more resistant to elevated pCO2 than other North Atlantic bivalves, such as Mercenaria mercenaria and Argopecten irradians, a finding that may be related to the biogeography and/or evolutionary history of these species and may have important implications for future bivalve restoration and aquaculture efforts. PMID:27293625

  12. Trace elements in major marketed marine bivalves from six northern coastal cities of China: concentrations and risk assessment for human health.

    PubMed

    Li, Peimiao; Gao, Xuelu

    2014-11-01

    One hundred and fifty nine samples of nine edible bivalve species (Argopecten irradians, Chlamys farreri, Crassostrea virginica, Lasaea nipponica, Meretrix meretrix, Mytilus edulis, Ruditapes philippinarum, Scapharca subcrenata and Sinonovacula constricta) were randomly collected from eight local seafood markets in six big cities (Dalian, Qingdao, Rizhao, Weifang, Weihai and Yantai) in the northern coastal areas of China for the investigation of trace element contamination. As, Cd, Cr, Cu, Hg, Pb and Zn were quantified. The risk of these trace elements to humans through bivalve consumption was then assessed. Results indicated that the concentrations of most of the studied trace element varied significantly with species: the average concentration of Cu in C. virginica was an order of magnitude higher than that in the remaining species; the average concentration of Zn was also highest in C. virginica; the average concentration of As, Cd and Pb was highest in R. philippinarum, C. farreri and A. irradians, respectively. Spatial differences in the concentrations of elements were generally less than those of interspecies, yet some elements such as Cr and Hg in the samples from different cities showed a significant difference in concentrations for some bivalve species. Trace element concentrations in edible tissues followed the order of Zn>Cu>As>Cd>Cr>Pb>Hg generally. Statistical analysis (one-way ANOVA) indicated that different species examined showed different bioaccumulation of trace elements. There were significant correlations between the concentrations of some elements. The calculated hazard quotients indicated in general that there was no obvious health risk from the intake of trace elements through bivalve consumption. But care must be taken considering the increasing amount of seafood consumption.

  13. The contribution of cytogenetics and flow cytometry for understanding the karyotype evolution in three Dorstenia (Linnaeus, 1753) species (Moraceae)

    PubMed Central

    Amaral-Silva, Paulo Marcos; Clarindo, Wellington Ronildo; Carrijo, Tatiana Tavares; Carvalho, Carlos Roberto; Praça-Fontes, Milene Miranda

    2016-01-01

    Abstract Chromosome morphometry and nuclear DNA content are useful data for cytotaxonomy and for understanding the evolutionary history of different taxa. However, the chromosome number is the only karyotype aspect reported for the species of Dorstenia so far. In this study, the nuclear genome size of Dorstenia arifolia (Lamarck, 1786), Dorstenia bonijesu (Carauta & C. Valente, 1983) and Dorstenia elata (Hooker, 1840) was evaluated and their karyotype morphometry accomplished, with the aim of verifying the potential of those parameters to understand evolutionary issues. Mean nuclear 2C value ranged from 2C = 3.49 picograms (pg) for Dorstenia elata to 2C = 5.47 pg for Dorstenia arifolia, a variation of ± 1.98 pg. Even though showing a marked difference in 2C value, the three species exhibited the same 2n = 32. Corroborating the flow cytometry data, differences in chromosome morphology were found among the karyotypes of the species investigated. Based on this and the only phylogeny proposed for Dorstenia thus far, structural rearrangements are related to the karyotype variations among the three species. Besides, the karyological analysis suggests a polyploid origin of the Dorstenia species studied here. PMID:27186340

  14. Phrenology, heredity and progress in George Combe's Constitution of Man.

    PubMed

    Jenkins, Bill

    2015-09-01

    The Constitution of Man by George Combe (1828) was probably the most influential phrenological work of the nineteenth century. It not only offered an exposition of the phrenological theory of the mind, but also presented Combe's vision of universal human progress through the inheritance of acquired mental attributes. In the decades before the publication of Darwin's Origin of Species, the Constitution was probably the single most important vehicle for the dissemination of naturalistic progressivism in the English-speaking world. Although there is a significant literature on the social and cultural context of phrenology, the role of heredity in Combe's thought has been less thoroughly explored, although both John van Wyhe and Victor L. Hilts have linked Combe's views on heredity with the transformist theories of Jean-Baptiste Lamarck. In this paper I examine the origin, nature and significance of his ideas and argue that Combe's hereditarianism was not directly related to Lamarckian transformism but formed part of a wider discourse on heredity in the early nineteenth century.

  15. A revision of the Neogene Conidae and Conorbidae (Gastropoda) of the Paratethys Sea.

    PubMed

    Harzhauser, Mathias; Landau, Bernard

    2016-12-22

    The Miocene Conidae and Conorbidae of the central- and south-eastern European Paratethys Sea are revised. In total, 74 species are described of which 10 are new species and 5 are documented for the first time from Paratethyan localities. Species descriptions and delimitations are partly based on morphometric data. In addition, colour patterns are described for the first time for the majority of species. In respect to the ongoing discussion on the supraspecific treatment of extant Conidae, we strongly focus on generic allocations and provide a key for the genera as understood herein. Biogeographically, the larger part of the assemblage indicates affiliation with modern western African faunas as indicated by the occurrence of genera such as Lautoconus, Kalloconus, Monteiroconus and Pseudonoduloconus. The relationship with Indo-West Pacific faunas is comparatively low. The high alpha-diversities observed for localities in the Pannonian, Transylvanian and Vienna basins, with up to 44 species, is a marker of tropical conditions in the Paratethys Sea during middle Miocene times.        Conasprella minutissima nov. sp., Kalloconus hendricksi nov. sp., Kalloconus letkesensis nov. sp., Kalloconus pseudohungaricus nov. sp., Lautoconus kovacsi nov. sp., Lautoconus pestensis nov. sp., Lautoconus quaggaoides nov. sp., Leporiconus paratethyianus nov. sp., Plagioconus breitenbergeri nov. sp. and Plagioconus bellissimus nov. sp. are described as new species; Conilithes eichwaldi nov. nom. is proposed as new name for Conus exiguus Eichwald, 1830 [non Lamarck, 1810].

  16. Environmental Epigenetics and a Unified Theory of the Molecular Aspects of Evolution: A Neo-Lamarckian Concept that Facilitates Neo-Darwinian Evolution.

    PubMed

    Skinner, Michael K

    2015-04-26

    Environment has a critical role in the natural selection process for Darwinian evolution. The primary molecular component currently considered for neo-Darwinian evolution involves genetic alterations and random mutations that generate the phenotypic variation required for natural selection to act. The vast majority of environmental factors cannot directly alter DNA sequence. Epigenetic mechanisms directly regulate genetic processes and can be dramatically altered by environmental factors. Therefore, environmental epigenetics provides a molecular mechanism to directly alter phenotypic variation generationally. Lamarck proposed in 1802 the concept that environment can directly alter phenotype in a heritable manner. Environmental epigenetics and epigenetic transgenerational inheritance provide molecular mechanisms for this process. Therefore, environment can on a molecular level influence the phenotypic variation directly. The ability of environmental epigenetics to alter phenotypic and genotypic variation directly can significantly impact natural selection. Neo-Lamarckian concept can facilitate neo-Darwinian evolution. A unified theory of evolution is presented to describe the integration of environmental epigenetic and genetic aspects of evolution.

  17. Experimental and geochemical evidence for derivation of the El Capitan Granite, California, by partial melting of hydrous gabbroic lower crust

    USGS Publications Warehouse

    Ratajeski, K.; Sisson, T.W.; Glazner, A.F.

    2005-01-01

    Partial melting of mafic intrusions recently emplaced into the lower crust can produce voluminous silicic magmas with isotopic ratios similar to their mafic sources. Low-temperature (825 and 850??C) partial melts synthesized at 700 MPa in biotite-hornblende gabbros from the central Sierra Nevada batholith (Sisson et al. in Contrib Mineral Petrol 148:635-661, 2005) have major-element and modeled trace-element (REE, Rb, Ba, Sr, Th, U) compositions matching those of the Cretaceous El Capitan Granite, a prominent granite and silicic granodiorite pluton in the central part of the Sierra Nevada batholith (Yosemite, CA, USA) locally mingled with coeval, isotopically similar quartz diorite through gabbro intrusions (Ratajeski et al. in Geol Soc Am Bull 113:1486-1502, 2001). These results are evidence that the El Capitan Granite, and perhaps similar intrusions in the Sierra Nevada batholith with lithospheric-mantle-like isotopic values, were extracted from LILE-enriched, hydrous (hornblende-bearing) gabbroic rocks in the Sierran lower crust. Granitic partial melts derived by this process may also be silicic end members for mixing events leading to large-volume intermediate composition Sierran plutons such as the Cretaceous Lamarck Granodiorite. Voluminous gabbroic residues of partial melting may be lost to the mantle by their conversion to garnet-pyroxene assemblages during batholithic magmatic crustal thickening. ?? Springer-Verlag 2005.

  18. [THE PROFESSORS OF THE NATIONAL MUSEUM OF NATURAL HISTORY AND THE SOCIETY OF THE FRIENDS OF THE SCIENCES OF WARSAW (1800-1832)].

    PubMed

    Daszkiewicz, Piotr

    2015-01-01

    The National Museum of Natural History played a crucial role in the formation of Polish scientific elites in the 19th century. Many Polish students were attending in Paris natural history, botany, zoology, chemistry and mineralogy courses. The Warsaw Society of Friends of Learning was the largest scientific society and one of the most important scientific institutions in Poland. It had also an impact on the political and cultural life of the country, occupied and deprived of freedom at that time. Amongst its founders and members, could be found listeners to the lectures of Lamarck, Haüy, Vauquelin, Desfontaines, Jussieu. Moreover, seven professors of the National Museum of Natural History were elected foreign members of the Warsaw Society of Friends of Learning: Cuvier, Desfontaines, Haüy, Jussieu, Latreille, Mirbel, Vauquelin. The article analyses this choice and underlines the relationship between these scientists and Warsaw's scientists. The results of this research allow to confirm that the National Museum of Natural History was the most important foreign institution in the 19th century for Polish science, and more specifically natural sciences.

  19. The biology of Dactylopius tomentosus (Hemiptera: Dactylopiidae).

    PubMed

    Mathenge, C W; Holford, P; Hoffmann, J H; Spooner-Hart, R; Beattie, G A C; Zimmermann, H G

    2009-12-01

    Dactylopius tomentosus (Lamarck) (Hemiptera: Dactylopiidae) is a cochineal insect whose host range is restricted to Cylindropuntia species (Caryophyllales: Cactaceae). This insect has been utilized successfully for biological control of Cylindropuntia imbricata (Haw.) F.M. Knuth in Australia and South Africa. Despite this, its biology has not been studied previously, probably due to the widely held belief that the biology of all Dactylopius species is similar. This study investigated the life cycle and the morphological and reproductive characteristics of D. tomentosus. Results revealed some unique characteristics of D. tomentosus: (i) eggs undergo a much longer incubation period, an average of 17 days compared to <1 day in its congeners; (ii) eggs are laid singly but are retained as an egg mass secured in a mesh of waxy threads attached to the female; (iii) the developmental times of males and females are longer compared to other Dactylopius spp. due to a longer egg incubation period; (iv) D. tomentosus does not undergo parthenogenesis; (v) D. tomentosus is smaller in size than its congeners; and (vi) male mating capacity and reproductive potential were both high and variable between males. There was a significant, strong, positive relationship (r = 0.93) between female mass and fecundity, whereas the relationship between the number of females mated per male that became gravid and their fecundity was negative (r = -0.68). Besides contributing to our knowledge of this economically important species, the finding of unique characteristics of D. tomentosus biology underlines the need to study each species in this genus.

  20. Ostreid herpesvirus in wild oysters from the Huelva coast (SW Spain).

    PubMed

    López-Sanmartín, M; López-Fernández, J R; Cunha, M E; De la Herrán, R; Navas, J I

    2016-08-09

    This is the first report of ostreid herpesvirus 1 microvariant (OsHV-1 µVar) infecting natural oyster beds located in Huelva (SW Spain). The virus was detected in 3 oyster species present in the intertidal zone: Crassostrea gigas (Thunberg, 1793), C. angulata (Lamarck, 1819) and, for the first time, in Ostrea stentina Payraudeau, 1826. Oysters were identified by a specific polymerase chain reaction (PCR) and posterior restriction fragment length polymorphism (RFLP) analysis based on cytochrome oxidase I (COI) mitochondrial DNA. Results confirmed that C. angulata still remains the dominant oyster population in SW Spain despite the introduction of C. gigas for cultivation in the late 1970s, and its subsequent naturalization. C. angulata shows a higher haplotype diversity than C. gigas. OsHV-1 virus was detected by PCR with C2/C6 pair primers. Posterior RFLP analyses with the restriction enzyme MfeI were done in order to reveal the OsHV-1 µVar. Detections were confirmed by DNA sequencing, and infections were evidenced by in situ hybridization in C. gigas, C. angulata and O. stentina samples. The prevalence was similar among the 3 oyster species but varied between sampling locations, being higher in areas with greater harvesting activities. OsHV-1 µVar accounted for 93% of all OsHV-1 detected.

  1. Phylogenetic systematics of the Indo-Pacific heart urchin Metalia Gray, 1885

    NASA Astrophysics Data System (ADS)

    Guevara-Plunkett, S.; Mooi, R.

    2014-12-01

    Irregular sea urchins of the clade Spatangoida, informally known as heart urchins, form a major and important component of tropical marine ecosystems. The spatangoid sea urchin genus, Metalia Gray 1885, a member of the spatangoid family Brissidae, is known primarily from the Indo-pacific region, although one species is known from the west coast of North America. Examination of new material is adding significantly to our knowledge of the morphology and taxonomy of Metalia. There are nine known species: Metalia spatagus (Linnaeus, 1758); Metalia sternalis (Lamarck, 1816); Metalia townsendi (Bell, 1904); Metalia nobilis Verrill, 1867-71; Metalia robillardi (de Loriol, 1876); Metalia dicrana H.L. Clark, 1917; Metalia latissima H.L. Clark, 1925; Metalia persica (Mortensen, 1940); Metalia angustus de Ridder, 1984; and Metalia kermadecensis Baker & Rowe, 1990. In addition, we have discovered two Philippines species new to science. Our work is presently removing ambiguities among characters used to typify all known Metalia, allowing for the establishment of more reliable species identification. A morphology-based phylogenetic analysis of Metalia using outgroup comparisons among brissid taxa such as Anametalia, Granobrissoides, Rhynobrissus, Brissopsis, Eupatatus, Meoma, and Brissus suggests that Metalia is monophyletic. An intriguing possibility is that the very distinctive and beautiful form from North America, Plagiobrissus, is very closely related to and possibly evolved from within Metalia. We are also studing various aspects of the biogeography and growth of Metalia.

  2. Adaptation or Malignant Transformation: The Two Faces of Epigenetically Mediated Response to Stress

    PubMed Central

    Zoldoš, Vlatka

    2013-01-01

    Adaptive response to stress is a fundamental property of living systems. At the cellular level, many different types of stress elicit an essentially limited repertoire of adaptive responses. Epigenetic changes are the main mechanism for medium- to long-term adaptation to accumulated (intense, long-term, or repeated) stress. We propose the adaptive deregulation of the epigenome in response to stress (ADERS) hypothesis which assumes that the unspecific adaptive stress response grows stronger with the increasing stress level, epigenetically activating response gene clusters while progressively deregulating other cellular processes. The balance between the unspecific adaptive response and the general epigenetic deregulation is critical because a strong response can lead to pathology, particularly to malignant transformation. The main idea of our hypothesis is the continuum traversed by a cell subjected to accumulated stress, which lies between an unspecific adaptive response and pathological deregulation—the two extremes sharing the same underlying cause, which is a manifestation of a unified epigenetically mediated adaptive response to stress. The evolutionary potential of epigenetic regulation in multigenerational adaptation is speculatively discussed in the light of neo-Lamarckism. Finally, an approach to testing the proposed hypothesis is presented, relying on either the publicly available datasets or on conducting new experiments. PMID:24187667

  3. Adaptation or malignant transformation: the two faces of epigenetically mediated response to stress.

    PubMed

    Vojta, Aleksandar; Zoldoš, Vlatka

    2013-01-01

    Adaptive response to stress is a fundamental property of living systems. At the cellular level, many different types of stress elicit an essentially limited repertoire of adaptive responses. Epigenetic changes are the main mechanism for medium- to long-term adaptation to accumulated (intense, long-term, or repeated) stress. We propose the adaptive deregulation of the epigenome in response to stress (ADERS) hypothesis which assumes that the unspecific adaptive stress response grows stronger with the increasing stress level, epigenetically activating response gene clusters while progressively deregulating other cellular processes. The balance between the unspecific adaptive response and the general epigenetic deregulation is critical because a strong response can lead to pathology, particularly to malignant transformation. The main idea of our hypothesis is the continuum traversed by a cell subjected to accumulated stress, which lies between an unspecific adaptive response and pathological deregulation--the two extremes sharing the same underlying cause, which is a manifestation of a unified epigenetically mediated adaptive response to stress. The evolutionary potential of epigenetic regulation in multigenerational adaptation is speculatively discussed in the light of neo-Lamarckism. Finally, an approach to testing the proposed hypothesis is presented, relying on either the publicly available datasets or on conducting new experiments.

  4. Neoparamoeba branchiphila infections in moribund sea urchins Diadema aff. antillarum in Tenerife, Canary Islands, Spain.

    PubMed

    Dyková, Iva; Lorenzo-Morales, Jacob; Kostka, Martin; Valladares, Basilio; Pecková, Hana

    2011-07-12

    A total of 109 sea urchins from 3 species collected in 2 localities off the coast of Tenerife Island, Spain, were examined for the presence of free-living amoebae in their coelomic fluid. Amoeba trophozoites were isolated exclusively from moribund individuals of long-spined sea urchins Diadema aff. antillarum (Philippi) (Echinoidea, Echinodermata) that manifested lesions related to sea urchin bald disease on their tests (16 out of 56 examined). No amoebae were detected in Arbacia lixula (L.) and Paracentrotus lividus (Lamarck). From the former sea urchin species, 8 strains, established from 10 primary isolates, were identified as Neoparamoeba branchiphila Dyková et al., 2005 using morphological and molecular methods. Results of this study (limited to the screening for free-living amoebae) together with data on agents of sea urchin mortalities reported to date justify the hypothesis that free-living amoebae play an opportunistic role in D. aff. antillarum mortality. The enlargement of the dataset of SSU rDNA sequences brought new insight into the phylogeny of Neoparamoeba species.

  5. The instinctual nation-state: non-Darwinian theories, state science and ultra-nationalism in Oka Asajirō's Evolution and Human Life.

    PubMed

    Sullivan, Gregory

    2011-01-01

    In his anthology of socio-political essays, Evolution and Human Life, Oka Asajirō (1868-1944), early twentieth century Japan's foremost advocate of evolutionism, developed a biological vision of the nation-state as super-organism that reflected the concerns and aims of German-inspired Meiji statism and anticipated aspects of radical ultra-nationalism. Drawing on non-Darwinian doctrines, Oka attempted to realize such a fused or organic state by enhancing social instincts that would bind the minzoku (ethnic nation) and state into a single living entity. Though mobilization during the Russo-Japanese War seemed to evince this super-organism, the increasingly contentious and complex society that emerged in the war's aftermath caused Oka to turn first to Lamarckism and eventually to orthogenesis in the hopes of preserving the instincts needed for a viable nation-state. It is especially in the state interventionist measures that Oka finally came to endorse in order to forestall orthogenetically-driven degeneration that the technocratic proclivities of his statist orientation become most apparent. The article concludes by suggesting that Oka's emphasis on degeneration, autarkic expansion, and, most especially, totalitarian submersion of individuals into the statist collectivity indicates a complex relationship between his evolutionism and fascist ideology, what recent scholarship has dubbed radical Shinto ultra-nationalism.

  6. Molluscicidal saponins from Sapindus mukorossi, inhibitory agents of golden apple snails, Pomacea canaliculata.

    PubMed

    Huang, Hui-Chi; Liao, Sin-Chung; Chang, Fang-Rong; Kuo, Yao-Haur; Wu, Yang-Chang

    2003-08-13

    Extracts of soapnut, Sapindus mukorossi Gaertn. (Sapindaceae) showed molluscicidal effects against the golden apple snail, Pomacea canaliculata Lamarck. (Ampullariidae) with LC(50) values of 85, 22, and 17 ppm after treating 24, 48, and 72 h, respectively. Bioassay-directed fractionation of S. mukorossi resulted in the isolation of one new hederagenin-based acetylated saponin, hederagenin 3-O-(2,4-O-di-acetyl-alpha-l-arabinopyranoside)-(1-->3)-alpha-l-rhamnopyranosyl-(1-->2)-alpha-l-arabinopyranoside (1), along with six known hederagenin saponins, hederagenin 3-O-(3,4-O-di-acetyl-alpha-l-arabinopyranoside)-(1-->3)-alpha-l-rhamnopyranosyl-(1-->2)-alpha-l-arabinopyranoside (2), hederagenin 3-O-(3-O-acetyl-beta-d-xylopyranosyl)-(1-->3)-alpha-l-rhamnopyranosyl-(1-->2)-alpha-l-arabinopyranoside (3), hederagenin 3-O-(4-O-acetyl-beta-d-xylopyranosyl)-(1-->3)-alpha-l-rhamnopyranosyl-(1-->2)-alpha-l-arabinopyranoside (4), hederagenin 3-O-(3,4-O-di-acetyl-beta-d-xylopyranosyl)-(1-->3)-alpha-l-rhamnopyranosyl-(1-->2)-alpha-l-arabinopyranoside (5), hederagenin 3-O-beta-d-xylopyranosyl-(1-->3)-alpha-l-rhamnopyranosyl-(1-->2)-alpha-l-arabinopyranoside (6), and hederagenin 3-O-alpha-l-arabinopyranoside (7). The bioassay data revealed that 1-7 were molluscicidal, causing 70-100% mortality at 10 ppm against the golden apple snail.

  7. Imposex in the golden apple snail Pomacea canaliculata in Taiwan.

    PubMed

    Liu, Wen-Hui; Chiu, Yuh-Wen; Huang, Da-Ji; Liu, Ming-Yie; Lee, Ching-Chang; Liu, Li-Lian

    2006-12-01

    The golden apple snail Pomacea canaliculata (Lamarck, 1822) was introduced into Taiwan intentionally in the early 1980s and has become a recurring pest that seriously threatens aquatic crops. In this study, a field description of imposex with a developed penis sheath and penis in female golden apple snails from crop/domestic wastewater drainage sites and a six-order river is presented for the first time. Based on the five field collections and the aquarium group, the vas deferens sequence (VDS) of P. canaliculata in imposex development was categorized into four stages, i.e., stage 0: without male genital system; stage 1: with rudimentary penis; stage 2: with rudimentary penis and penis sheath; and stage 3: the rudimentary penis developing into penis pouch and penis. The VDS indices varied between 1.07 and 2.82 and were lowest in the aquarium group and Yuanlin2. Regarding the severity of imposex, the aquarium group was less pronounced, as illustrated by the length of penis sheath and penis length, than the field collections (p<0.05). In respect of the penis length, males of the most imposex-affected site were up to 15% shorter than that of the aquarium group. Negative correlations between male penis length and female imposex characters (i.e., penis length and penis sheath length) were also observed.

  8. The search for purpose in a post-Darwinian universe: George Bernard Shaw, 'creative evolution', and Shavian eugenics: 'The dark side of the force'.

    PubMed

    Hale, Piers J

    2006-01-01

    The Irish playwright and socialist George Bernard Shaw has been of marginal concern for historians of biology because his vitalist Lamarckism has been viewed as out of step with contemporary science. However, Julian Huxley and J.B.S. Haldane were certainly of the opinion that Shaw was a man of influence in this regard and took pains to counter his views in their own attempts to engage the public in science. Previously, Shaw's colleague and friend H.G. Wells had also agued with Shaw from his own mechanistic neo-Darwinian perspective. The very public debate between Shaw and Wells, which continued to concern Huxley and Haldane, shows that public concern over the moral implications of Darwinism has a long history. Taking into account the opinions of John Maynard Smith on this matter, I suggest that a consideration of Shaw in this context can give us an understanding of the historical popularity of vitalist teleology as well as of the persistent ambivalence to the non-normative character of Darwinism.

  9. Pomacea canaliculata (Mollusca, Gastropoda) in Patagonia: potential role of climatic change in its dispersion and settlement.

    PubMed

    Darrigran, G; Damborenea, C; Tambussi, A

    2011-02-01

    Pomacea canaliculata (Lamarck, 1822) (Mollusca Gastropoda) shows a large native distribution range in South America, reaching as far south as 37º S (Buenos Aires, Argentina). This species was deliberately introduced into Southeast Asia around 1980 and subsequently underwent a rapid intentional or accidental dispersal into many countries in the region. It was also introduced into North and Central America and Hawaii. In this contribution we record the presence of P. canaliculata in Patagonia, assessing the possible influence of climatic change in the new establishment of this species there. Three samplings (between September 2004 and April 2005) were carried out at 38º 58' 20.2" S-68º 11' 27.3" W. In the sampling we found two adult specimens of P. canaliculata and numerous egg clutches. Pomacea canaliculata is naturally distributed in the Plata and Amazon Basins. The southern boundary of this species has been established as the isotherms of 14 ºC and 16 ºC in Buenos Aires province, and precipitations of 900 to 600 mm/year. This study also analysed variations in annual temperature and precipitation in Patagonia. Average temperatures show an increase over the years, although not constantly. Important modifications in precipitation regime in northern Patagonia, triggered by global climatic changes, could be beneficial for the settlement of populations of P. canaliculata in this new area, where precipitation increased enough to reach values similar to those in the southernmost area of distribution of this species.

  10. The search for minimum-energy atomic configurations on a lattice: Lamarckian twist on Darwinian Evolution

    NASA Astrophysics Data System (ADS)

    D'Avezac, Mayeul; Zunger, Alex

    2008-03-01

    We examine how two different mechanisms proposed historically for biological evolution compare for the determination of crystal structures from random initial lattice-configurations. The Darwinian theory of evolution contends that the genetic makeup inherited at birth is the one passed on to offsprings. Lamarck surmised additionally that offspring can inherit acquired traits. In the case of lattice-configurations, such improvements consist in A<->B transmutations of atomic sites as guided by ``Virtual Atom'' energy-gradients(M. d'Avezac and Alex Zunger, J. Phys.: Cond. Matt. 19, 402201 (2007)). This hybrid evolution is shown to provide an efficient solution to a generalized Ising Hamiltonian, illustrated by finding the ground-states of face-centered cubic Au1-xPdx using a cluster-expansion functional fitted to first-principles total-energies. For example, finding all minimum-energy structures of a 32-atom supercell with 95,% confidence requires evaluating 750, 000 configurations using local improvements only, 150, 000 using a reciprocal-space genetic algorithm only, and 14,000 using the hybrid approach. We consider applying the lamarckian search to further functionals.

  11. Revision of the genus Turris Batsch, 1789 (Gastropoda: Conoidea: Turridae) with the description of six new species

    PubMed Central

    Kilburn, Richard N.; Fedosov, Alexander E.; Olivera, Baldomero M.

    2012-01-01

    The taxonomy of the genus Turris Batsch, 1789, type genus of the family Turridae, widespread in shallow-water habitats of tropic Indo-Pacific, is revised. A total of 31 species of Turris, are here recognized as valid. New species described: Turris chaldaea, Turris clausifossata, Turris guidopoppei, Turris intercancellata, Turris kantori, T. kathiewayae. Homonym renamed: Turris bipartita nom. nov. for Pleurotoma variegata Kiener, 1839 (non Philippi, 1836). New synonymies: Turris ankaramanyensis Bozzetti, 2006 = Turris tanyspira Kilburn, 1975; Turris imperfecti, T. nobilis, T. pulchra and T. tornatum Röding, 1798, and Turris assyria Olivera, Seronay & Fedosov, 2010 = T. babylonia; Turris dollyi Olivera, 2000 = Pleurotoma crispa Lamarck, 1816; Turris totiphyllis Olivera, 2000 = Turris hidalgoi Vera-Peláez, Vega-Luz & Lozano-Francisco, 2000; Turris kilburni Vera-Peláez, Vega-Luz & Lozano-Francisco, 2000 = Turris pagasa Olivera, 2000; Turris (Annulaturris) munizi Vera-Peláez, Vega-Luz & Lozano-Francisco, 2000 = Gemmula lululimi Olivera, 2000. Revised status: Turris intricata Powell, 1964, Pleurotoma variegata Kiener, 1839 (non Philippi, 1836) and Pleurotoma yeddoensis Jousseaume, 1883, are regarded as full species (not subspecies of Turris crispa). Neotype designated: For Pleurotoma garnonsii Reeve, 1843, to distinguish it from Turris garnonsii of recent authors, type locality emended to Zanzibar. New combination: Turris orthopleura Kilburn, 1983, is transferred to genus Makiyamaia, family Clavatulidae. PMID:23847408

  12. Who invented the dichotomous key? Richard Waller's watercolors of the herbs of Britain.

    PubMed

    Griffing, Lawrence R

    2011-12-01

    On 27 March 1689, Richard Waller, Fellow and Secretary of the Royal Society presented his "Tables of the English Herbs reduced to such an order, as to find the name of them by their external figures and shapes" to his assembled colleagues at a meeting of the Royal Society. These tables were developed for the novice by being color images, composed in pencil and watercolor, of selected plants and their distinguishing characteristics. The botanical watercolors for the tables are now a Turning-the-Pages document online on the website of the Royal Society. However, for the past 320 years, the scientific context for the creation of these outstanding botanical watercolors has remained obscure. These tables were developed by Waller as an image-based dichotomous key, pre-dating by almost 100 years the text-based dichotomous keys in the first edition of Flora Française (1778) by Jean Baptiste Lamarck, who is generally given priority for the development of the dichotomous key. How these large folio images were arranged to illustrate a dichotomous key is unknown, but an arrangement based on Waller's description is illustrated here as leaf-ordering for the separate hierarchical clusters (tables). Although only 24 species of watercolored dicot herbs out of a total of 65 in the set of watercolors (the others being monocots) are used in these tables, they are a "proof of concept", serving as models upon which a method is based, that of using a key composed of dichotomous choices for aiding identification.

  13. "Stand up straight": notes toward a history of posture.

    PubMed

    Gilman, Sander L

    2014-03-01

    The essay presents a set of interlinked claims about posture in modern culture. Over the past two centuries it has come to define a wide range of assumptions in the West from what makes human beings human (from Lamarck to Darwin and beyond) to the efficacy of the body in warfare (from Dutch drill manuals in the 17th century to German military medical studies of soldiers in the 19th century). Dance and sport both are forms of posture training in terms of their own claims. Posture separates 'primitive' from 'advanced' peoples and the 'ill' from the 'healthy.' Indeed an entire medical sub-specialty developed in which gymnastics defined and recuperated the body. But all of these claims were also part of a Western attempt to use posture (and the means of altering it) as the litmus test for the healthy modern body of the perfect citizen. Focusing on the centrality of posture in two oddly linked moments of modern thought--modern Zionist thought and Nationalism in early 20th century China--in terms of bodily reform, we show how "posture" brings all of the earlier debates together to reform the body.

  14. The cushion–star Parvulastra exigua in South Africa: one species or more?

    PubMed Central

    Payne, Robyn P.; Griffiths, Charles L.; von der Heyden, Sophie; Koch, Erich

    2015-01-01

    Abstract The cushion–star Parvulastra exigua (Lamarck, 1816) is a widely distributed member of the temperate intertidal fauna in the southern hemisphere. In South Africa, it occurs in sympatry with the endemic Parvulastra dyscrita (Clark, 1923), the two species being differentiated predominantly by gonopore placement. Several recent studies have suggested that there may be additional cryptic species within the Parvulastra exigua complex in South Africa, based variously on color morphology, genetic evidence and the differential placement of the gonopores. This paper attempts to resolve whether one or more species are represented within Parvulastra exigua. A total of 346 Parvulastra exigua and 8 Parvulastra dyscrita were collected from sites on the west and south–west coasts of South Africa; morphological, anatomical and genetic analyses were performed to determine whether cryptic species and/or Parvulastra exigua specimens with aboral gonopores were present. Results show that neither cryptic species nor Parvulastra exigua specimens with aboral gonopores occur at these sites. This study thus refutes previous claims of the existence of aboral gonopores in South African Parvulastra exigua, and suggests that a single species is represented. The distinction between Parvulastra exigua and Parvulastra dyscrita is also confirmed, and features separating these two species are clarified and documented. PMID:26478703

  15. The turbellarian urastoma cyprinae from edible mussels mytilus galloprovincialis and mytilus californianus in baja california, NW Mexico

    PubMed

    Caceres-martinez; Vasquez-yeomans; Sluys

    1998-11-01

    The turbellarian Urastoma cyprinae (Graff, 1913) was found in the mantle cavity of Mytilus galloprovincialis Lamarck and Mytilus californianus Conrad, on the Pacific coast of Baja California NW Mexico. This is the first record of this turbellarian for bivalves from the Pacific coast of North America. In M. galloprovincialis from an exposed rocky shore, prevalence ranged from 10 to 87% and mean number of turbellarians per infested mussel was 1.9; in a culture area prevalence ranged from 57 to 100% and the mean number of turbellarians per infested mussel was 7.4. In the protected and polluted areas U. cyprinae was scarce or absent, prevalence ranging from 0 to 15% and the mean number of turbellarian per infested mussel being 0.07. The prevalence and the mean number of turbellarians per M. californianus in the exposed rocky shore ranged from 20 to 100% and 5.1, respectively. There were more worms in the larger mussels. Demibranches of M. galloprovincialis and M. californianus may be injured by the presence of turbellarians. An infiltration of hemocyte cells around the turbellarians was observed in both species and the blood sinuses in the infected area were engorged. Recorded damage was not related to a negative effect on the condition index of mussels. Copyright 1998 Academic Press.

  16. Bucardium grateloupianum n. sp. from the Lower Miocene of Aquitaine with    taxonomic comments on some fossil species from Europe (Bivalvia, Cardiidae).

    PubMed

    Perna, Rafael La

    2016-10-26

    The genus Bucardium J. E. Gray, 1853 has been widely used in the past literature, either for living and fossil cardiids, but only a single species was known, its type species B. ringens (Bruguière, 1789), living in the tropical waters of West Africa. Another species, from the Lower Miocene of the Aquitaine Basin, turned out to be undescribed, though known since the 19th century. It is herein described as Bucardium grateloupianum n. sp. The genus seems to have always had a low diversity and a tropical distribution. Its disappearance in Europe coincides with the general cooling trend recorded after the Middle Miocene. Several poorly known cardiids from the Lower-Middle Miocene of France and Austria and from the Upper Oligocene of Hungary show closer morphological affinities with the living Cardium indicum Lamarck, 1819, rather than with the genus Bucardium or with Cardium costatum Linnaeus, 1758, the type species of Cardium Linnaeus, 1758. These affinities suggest the need of a systematic reappraisal of the living and fossil species currently assigned to Cardium.

  17. [The scholarly program of Johann Friedrich Meckel the Younger (1781-1833) and it importance for the development of life sciences].

    PubMed

    Göbbel, Luminita; Schultka, Rüdiger

    2002-11-01

    Although Johann Friedrich Meckel the Younger was one of the most famous anatomists, his research work has been severely neglected in the recent historiographical literature on the German morphology. The goal of our study is to approach a general characterization of his research program. Our analysis reveals that Meckel introduced the Cuvierian empiricism in Germany, but he also considered the "Abstraktion" as a main component of the scientific knowledge. According to his epistemology on nascent organisms and transmutable species, both, variability and relatedness of the organic forms are important to the same degree. Meckel explicitly adopted the Jean-Baptiste de Lamarcks (1744-1829) evolutionary theories. Even though in Meckel's discourse about diversity the Cuvierian notion of "functional adaptation" was preserved, the main goal of his research program was to demonstrate empirically the "Allgemeinheit des Bildungstypus". For this purpose, he considered the entire variety of the animal kingdom: normal as well as abnormal organisms, adult specimens and above all embryos. Moreover, he believed that the abnormal development is due to the same laws as the normal development. He applied parallelisms to a new domain, the study of malformation. With Meckel's researches on teratology, a new era in the analyses of the anomalies was opened. They became an integral part of the natural diversity and thus a highly exploited subject of biomedical researches. Meckel's empirical and epistemological writings on the embryology, comparative embryology, teratology, pathology, systematics and comparative anatomy have largely contributed to the foundation of the biological research.

  18. Evaluation of Vaccinium spp. for Illinoia pepperi (Hemiptera: Aphididae) performance and phenolic content.

    PubMed

    Ranger, Christopher M; Johnson-Cicalese, Jennifer; Polavarapu, Sridhar; Vorsa, Nicholi

    2006-08-01

    Host acceptance and population parameters of the aphid Illinoia pepperi (MacGillivray) (Hemiptera: Aphididae) were measured on highbush blueberry, Vaccinium corymbosum L. 'Elliott', and the wild species Vaccinium boreale Hall and Aalders, Vaccinium tenellum Aiton, Vaccinium pallidum Aiton, Vaccinium hirsutum Buckley, Vaccinium myrsinites Lamarck, and Vaccinium darrowi Camp. After 24 h of exposure, significantly fewer aphids remained in contact with V. boreale and V. hirsutum compared with V. corymbosum Elliott, V. darrowi, and V. pallidum. Length of the prereproductive period of I. pepperi was significantly longer on V. boreale and V. myrsinites, in contrast to V. corymbosum. Fecundity was also lower on V. boreale, V. hirsutum, V. myrsinites, and V. darrowi. Survivorship of I. pepperi 42 d after birth was significantly lower on V. hirsutum compared with the remaining Vaccinium spp. Reduced I. pepperi performance resulted in significantly lower intrinsic rate of increase (r(m)) values being associated with V. myrsinites, V. boreale, V. hirsutum, and V. darrowi, compared with V. corymbosum. Net reproductive rate (R(o)), generation time (T), and doubling time (T(d)) of I. pepperi also were affected by the Vaccinium spp. Total phenolic and flavonol content varied between Vaccinium spp., with some high phenolic content Vaccinium spp. having reduced aphid performance. However, no significant correlation between phenolics and I. pepperi performance was detected. Results from this study identified several potential sources of aphid resistance traits in wild Vaccinium spp.

  19. Erasmus Darwin, Herbert Spencer, and the origins of the evolutionary worldview in British provincial scientific culture, 1770-1850.

    PubMed

    Elliott, Paul

    2003-03-01

    The significance of Herbert Spencer's evolutionary philosophy has been generally recognized for over a century, as the familiarity of his phrase "survival of the fittest" indicates, yet accounts of the origins of his system still tend to follow too closely his own description, written many decades later. This essay argues that Spencer's own interpretation of his intellectual development gives an inadequate impression of the debt he owed to provincial scientific culture and its institutions. Most important, it shows that his evolutionism was originally stimulated by his association with the Derby philosophical community, for it was through this group--of which his father, who also appears to have espoused a deistic evolutionary theory, was a member--that he was first exposed to progressive Englightenment social and educational philosophies and to the evolutionary worldview of Erasmus Darwin, the first president of the Derby Philosophical Society. Darwin's scheme was the first to incorporate biological evolution, associationist psychology, evolutionary geology, and cosmological developmentalism. Spencer's own implicit denials of the link with Darwin are shown to be implausible in the face of Darwin's continuing influence on the Derby savants, the product of insecurity in his later years when he feared for his reputation as Lamarckism became increasingly untenable.

  20. Repression of mesodermal fate by foxa, a key endoderm regulator of the sea urchin embryo.

    PubMed

    Oliveri, Paola; Walton, Katherine D; Davidson, Eric H; McClay, David R

    2006-11-01

    The foxa gene is an integral component of the endoderm specification subcircuit of the endomesoderm gene regulatory network in the Strongylocentrotus purpuratus embryo. Its transcripts become confined to veg2, then veg1 endodermal territories, and, following gastrulation, throughout the gut. It is also expressed in the stomodeal ectoderm. gatae and otx genes provide input into the pregastrular regulatory system of foxa, and Foxa represses its own transcription, resulting in an oscillatory temporal expression profile. Here, we report three separate essential functions of the foxa gene: it represses mesodermal fate in the veg2 endomesoderm; it is required in postgastrular development for the expression of gut-specific genes; and it is necessary for stomodaeum formation. If its expression is reduced by a morpholino, more endomesoderm cells become pigment and other mesenchymal cell types, less gut is specified, and the larva has no mouth. Experiments in which blastomere transplantation is combined with foxa MASO treatment demonstrate that, in the normal endoderm, a crucial role of Foxa is to repress gcm expression in response to a Notch signal, and hence to repress mesodermal fate. Chimeric recombination experiments in which veg2, veg1 or ectoderm cells contained foxa MASO show which region of foxa expression controls each of the three functions. These experiments show that the foxa gene is a component of three distinct embryonic gene regulatory networks.

  1. Anandamide (arachidonylethanolamide), a brain cannabinoid receptor agonist, reduces sperm fertilizing capacity in sea urchins by inhibiting the acrosome reaction.

    PubMed Central

    Schuel, H; Goldstein, E; Mechoulam, R; Zimmerman, A M; Zimmerman, S

    1994-01-01

    Anandamide (arachidonylethanolamide) is an endogenous cannabinoid receptor agonist in mammalian brain. Sea urchin sperm contain a high-affinity cannabinoid receptor similar to the cannabinoid receptor in mammalian brain. (-)-delta 9-Tetrahydrocannabinol (THC), the primary psychoactive cannabinoid in marihuana, reduces the fertilizing capacity of sea urchin sperm by blocking the acrosome reaction that normally is stimulated by a specific ligand in the egg's jelly coat. We now report that anandamide produces effects similar to those previously obtained with THC in Strongylocentrotus purpuratus in reducing sperm fertilizing capacity and inhibiting the egg jelly-stimulated acrosome reaction. Arachidonic acid does not inhibit the acrosome reaction under similar conditions. The adverse effects of anandamide on sperm fertilizing capacity and the acrosome reaction are reversible. The receptivity of unfertilized eggs to sperm and sperm motility are not impaired by anandamide. Under conditions where anandamide completely blocks the egg jelly-stimulated acrosome reaction, it does not inhibit the acrosome reaction artificially initiated by ionomycin, which promotes Ca2+ influx, and nigericin, which activates K+ channels in sperm. These findings provide additional evidence that the cannabinoid receptor in sperm plays a role in blocking the acrosome reaction, indicate that anandamide or a related molecule may be the natural ligand for the cannabinoid receptor in sea urchin sperm, and suggest that binding of anandamide to the cannabinoid receptor modulates stimulus-secretion-coupling in sperm by affecting an event prior to ion channel opening. PMID:8052642

  2. A 45,000-mol-wt protein from unfertilized sea urchin eggs severs actin filaments in a calcium-dependent manner and increases the steady-state concentration of nonfilamentous actin

    PubMed Central

    1984-01-01

    A 45,000-mol-wt protein has been purified from unfertilized sea urchin (Strongylocentrotus purpuratus) eggs. The isolation scheme includes DEAE cellulose ion-exchange chromatography, gel filtration, and hydroxylapatite chromatography. The homogeneity of the isolated protein is greater than 90% by SDS PAGE. The 45,000-mol-wt protein reduces the viscosity of actin filaments in a Ca2+-dependent manner. The free calcium concentration required for the activity of this protein is in the micromolar range. Electron microscopic studies reveal that the formation of short filaments parallels the decrease in viscosity. Energy transfer and sedimentation experiments indicate a net disassembly of actin filaments and an increase in the steady-state nonfilamentous actin concentration in the presence of Ca2+ ions and the 45,000-mol-wt protein. The increase in the steady-state nonfilamentous actin concentration is proportional to the amount of 45,000-mol-wt protein added. The actin molecules disassembled by the addition of the 45,000-mol-wt protein are capable of polymerization. PMID:6540784

  3. High-Density Genetic Mapping with Interspecific Hybrids of Two Sea Urchins, Strongylocentrotus nudus and S. intermedius, by RAD Sequencing.

    PubMed

    Zhou, Zunchun; Liu, Shikai; Dong, Ying; Gao, Shan; Chen, Zhong; Jiang, Jingwei; Yang, Aifu; Sun, Hongjuan; Guan, Xiaoyan; Jiang, Bei; Wang, Bai

    2015-01-01

    Sea urchins have long been used as research model organisms for developmental biology and evolutionary studies. Some of them are also important aquaculture species in East Asia. In this work, we report the construction of RAD-tag based high-density genetic maps by genotyping F1 interspecific hybrids derived from a crossing between a female sea urchin Strongylocentrotus nudus and a male Strongylocentrotus intermedius. With polymorphisms present in these two wild individuals, we constructed a female meiotic map containing 3,080 markers for S. nudus, and a male meiotic map for S. intermedius which contains 1,577 markers. Using the linkage maps, we were able to anchor a total of 1,591 scaffolds (495.9 Mb) accounting for 60.8% of the genome assembly of Strongylocentrotus purpuratus. A genome-wide scan resulted in the identification of one putative QTL for body size which spanned from 25.3 cM to 30.3 cM. This study showed the efficiency of RAD-Seq based high-density genetic map construction using F1 progenies for species with no prior genomic information. The genetic maps are essential for QTL mapping and are useful as framework to order and orientate contiguous scaffolds from sea urchin genome assembly. The integration of the genetic map with genome assembly would provide an unprecedented opportunity to conduct QTL analysis, comparative genomics, and population genetics studies.

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

    PubMed Central

    Jurgens, Laura J.; Rogers-Bennett, Laura; Raimondi, Peter T.; Schiebelhut, Lauren M.; Dawson, Michael N.; Grosberg, Richard K.; Gaylord, Brian

    2015-01-01

    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. PMID:26039349

  5. Identification of purple sea urchin telomerase RNA using a next-generation sequencing based approach.

    PubMed

    Li, Yang; Podlevsky, Joshua D; Marz, Manja; Qi, Xiaodong; Hoffmann, Steve; Stadler, Peter F; Chen, Julian J-L

    2013-06-01

    Telomerase is a ribonucleoprotein (RNP) enzyme essential for telomere maintenance and chromosome stability. While the catalytic telomerase reverse transcriptase (TERT) protein is well conserved across eukaryotes, telomerase RNA (TR) is extensively divergent in size, sequence, and structure. This diversity prohibits TR identification from many important organisms. Here we report a novel approach for TR discovery that combines in vitro TR enrichment from total RNA, next-generation sequencing, and a computational screening pipeline. With this approach, we have successfully identified TR from Strongylocentrotus purpuratus (purple sea urchin) from the phylum Echinodermata. Reconstitution of activity in vitro confirmed that this RNA is an integral component of sea urchin telomerase. Comparative phylogenetic analysis against vertebrate TR sequences revealed that the purple sea urchin TR contains vertebrate-like template-pseudoknot and H/ACA domains. While lacking a vertebrate-like CR4/5 domain, sea urchin TR has a unique central domain critical for telomerase activity. This is the first TR identified from the previously unexplored invertebrate clade and provides the first glimpse of TR evolution in the deuterostome lineage. Moreover, our TR discovery approach is a significant step toward the comprehensive understanding of telomerase RNP evolution.

  6. Kelp forest monitoring 1992 annual report. Channel Islands National Park. Final report

    SciTech Connect

    Richards, D.; Kushner, D.

    1992-12-31

    The 1992 results of the Channel Islands Natioanl Park Kelp Forest Monitoring Project are described in this report. Population dynamics of 68 taxa or categories of algae, 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 point contacts, fish and video transects, photogrammetric plots, size frequency measurements, artifical recruitment habitats, and species list surveys. Some batheothermograph data was collected. In 1992, nine sites and healthy kelp forests while seven were mostly barren. The seven barren sites consisted of one that was dominated by the aggregated red sea cucumber, Pachythyone rubra, one was barren with high sedimentation, one was domainated by red sea urchins, Strongylocentrotus franciscanus, and four sites were dominated by purple sea urchins, Strongylocentrotus purpuratus, three of which had signs of a developing kelp forest. Wasting disease was observed in sea stars and a wasting syndrome was observed in sea urchins. Fish recruitment appeared to be late this year. Size frequency measurements were taken from artificial recruitment modules (previously named `abalone recruitment modules`) at six of the sites.

  7. Phylogeny and biogeography of the fruit doves (Aves: Columbidae).

    PubMed

    Cibois, Alice; Thibault, Jean-Claude; Bonillo, Céline; Filardi, Christopher E; Watling, Dick; Pasquet, Eric

    2014-01-01

    We reconstruct the phylogeny of fruit doves (genus Ptilinopus) and allies with a dense sampling that includes almost all species, based on mitochondrial and nuclear sequence data. We evaluate the most likely biogeographic scenario for the evolution of this group that colonized many islands of the Pacific Ocean. We also investigate the evolution of one of the main plumage character of fruit doves (the color of the crown), and we propose several revisions of the group's systematics. All Ptilinopus taxa formed a monophyletic group that includes two morphologically distinct genera, Alectroenas and Drepanoptila, confirming a previous result found with less species and genes. The divergence time analysis suggests that the basal divergences within Ptilinopus dated to the Early Oligocene, and the biogeographic analysis indicates that fruit doves originated most probably from the proto New Guinea region. The earliest dispersals from the New Guinea region to Oceania occurred with the colonization of New Caledonia and Fiji. A large group of Polynesian species (Central and Eastern), as well as the three taxa found in Micronesia and four species from the Guinean-Moluccan region, form the "purpuratus" clade, the largest diversification of fruit doves within Oceania, which also has a New Guinean origin. However, the eastbound colonization of fruit doves was not associated with a significant increase of their diversification rate. Overall, the Melanesian region did not act as a cradle for fruit doves, in contrast to the New Guinea region which is found as the ancestral area for several nodes within the phylogeny.

  8. Discovery of sea urchin NGFFFamide receptor unites a bilaterian neuropeptide family

    PubMed Central

    Semmens, Dean C.; Beets, Isabel; Rowe, Matthew L.; Blowes, Liisa M.; Oliveri, Paola; Elphick, Maurice R.

    2015-01-01

    Neuropeptides are ancient regulators of physiology and behaviour, but reconstruction of neuropeptide evolution is often difficult owing to lack of sequence conservation. Here, we report that the receptor for the neuropeptide NGFFFamide in the sea urchin Strongylocentrotus purpuratus (phylum Echinodermata) is an orthologue of vertebrate neuropeptide-S (NPS) receptors and crustacean cardioactive peptide (CCAP) receptors. Importantly, this has facilitated reconstruction of the evolution of two bilaterian neuropeptide signalling systems. Genes encoding the precursor of a vasopressin/oxytocin-type neuropeptide and its receptor duplicated in a common ancestor of the Bilateria. One copy of the precursor retained ancestral features, as seen in highly conserved vasopressin/oxytocin–neurophysin-type precursors. The other copy diverged, but this took different courses in protostomes and deuterostomes. In protostomes, the occurrence of a disulfide bridge in neuropeptide product(s) of the precursor was retained, as in CCAP, but with loss of the neurophysin domain. In deuterostomes, we see the opposite scenario—the neuropeptides lost the disulfide bridge, and neurophysin was retained (as in the NGFFFamide precursor) but was subsequently lost in vertebrate NPS precursors. Thus, the sea urchin NGFFFamide precursor and receptor are ‘missing links’ in the evolutionary history of neuropeptides that control ecdysis in arthropods (CCAP) and regulate anxiety in humans (NPS). PMID:25904544

  9. The carboxylesterase/cholinesterase gene family in invertebrate deuterostomes.

    PubMed

    Johnson, Glynis; Moore, Samuel W

    2012-06-01

    Carboxylesterase/cholinesterase family members are responsible for controlling the nerve impulse, detoxification and various developmental functions, and are a major target of pesticides and chemical warfare agents. Comparative structural analysis of these enzymes is thus important. The invertebrate deuterostomes (phyla Echinodermata and Hemichordata and subphyla Urochordata and Cephalochordata) lie in the transition zone between invertebrates and vertebrates, and are thus of interest to the study of evolution. Here we have investigated the carboxylesterase/cholinesterase gene family in the sequenced genomes of Strongylocentrotus purpuratus (Echinodermata), Saccoglossus kowalevskii (Hemichordata), Ciona intestinalis (Urochordata) and Branchiostoma floridae (Cephalochordata), using sequence analysis of the catalytic apparatus and oligomerisation domains, and phylogenetic analysis. All four genomes show blurring of structural boundaries between cholinesterases and carboxylesterases, with many intermediate enzymes. Non-enzymatic proteins are well represented. The Saccoglossus and Branchiostoma genomes show evidence of extensive gene duplication and retention. There is also evidence of domain shuffling, resulting in multidomain proteins consisting either of multiple carboxylesterase domains, or of carboxylesterase/cholinesterase domains linked to other domains, including RING finger, chitin-binding, immunoglobulin, fibronectin type 3, CUB, cysteine-rich-Frizzled, caspase activation and 7tm-1, amongst others. Such gene duplication and domain shuffling in the carboxylesterase/cholinesterase family appears to be unique to the invertebrate deuterostomes, and we hypothesise that these factors may have contributed to the evolution of the morphological complexity, particularly of the nervous system and neural crest, of the vertebrates.

  10. Reduction of the fertilizing capacity of sea urchin sperm by cannabinoids derived from marihuana. II. Ultrastructural changes associated with inhibition of the acrosome reaction.

    PubMed

    Chang, M C; Schuel, H

    1991-05-01

    Pretreatment of Strongylocentrotus purpuratus sperm with delta 9-tetrahydrocannabinol (THC) prevents the triggering of the acrosome reaction by egg jelly. Examination of THC-treated sperm by transmission electron microscopy reveals that the membrane fusion reaction between the sperm plasma membrane and the acrosomal membrane is completely blocked. Electron-dense deposits are present in the subacrosomal fossa and in the centriolar fossa. The nuclear envelope is fragmented in close proximity to the electron-dense deposits. The electron-dense deposits are not bound by a limiting membrane, stain positively for lipid with thymol and farnesol, and disappear from THC-treated sperm that are extracted with chloroform:methanol (2:1) after glutaraldehyde fixation. The electron-dense deposits are lipid in nature and may be a hydrolytic product of the nuclear envelope. Electron-dense deposits are seen in sperm after 1-10 min treatment with 5-100 microM THC. The electron-dense deposits disappear after removal of THC from the sperm by washing, but the fragmented nuclear envelope in the subacrosomal fossa persists. Cannabidiol (CBD) and cannabinol (CBN) also inhibit the triggering of the acrosome reaction by egg jelly and produce ultrastructural changes in the sperm identical to those elicited by THC. Enhanced phospholipase activity stimulated by THC, CBD, and CBN may be the cause of the accumulation of lipid deposits in the sperm. Metabolites derived from this modification of membrane phospholipids may prevent triggering of the acrosome reaction by egg jelly and thereby inhibit fertilization.

  11. Multidrug efflux transporters limit accumulation of inorganic, but not organic, mercury in sea urchin embryos.

    PubMed

    Bosnjak, Ivana; Uhlinger, Kevin R; Heim, Wesley; Smital, Tvrtko; Franekić-Colić, Jasna; Coale, Kenneth; Epel, David; Hamdoun, Amro

    2009-11-01

    Mercuric compounds are persistent global pollutants that accumulate in marine organisms and in humans who consume them. While the chemical cycles and speciation of mercury in the oceans are relatively well described, the cellular mechanisms that govern which forms of mercury accumulate in cells and why they persist are less understood. In this study we examined the role of multidrug efflux transport in the differential accumulation of inorganic (HgCl(2)) and organic (CH(3)HgCl) mercury in sea urchin (Strongylocentrotus purpuratus) embryos. We found that inhibition of MRP/ABCC-type transporters increases intracellular accumulation of inorganic mercury but had no effect on accumulation of organic mercury. Similarly, pharmacological inhibition of metal conjugating enzymes by ligands GST/GSH significantly increases this antimitotic potency of inorganic mercury, but had no effect on the potency of organic mercury. Our results point to MRP-mediated elimination of inorganic mercury conjugates as a cellular basis for differences in the accumulation and potency of the two major forms of mercury found in marine environments.

  12. Lesions of Copper Toxicosis in Captive Marine Invertebrates With Comparisons to Normal Histology.

    PubMed

    LaDouceur, E E B; Wynne, J; Garner, M M; Nyaoke, A; Keel, M K

    2016-05-01

    Despite increasing concern for coral reef ecosystem health within the last decade, there is scant literature concerning the histopathology of diseases affecting the major constituents of coral reef ecosystems, particularly marine invertebrates. This study describes histologic findings in 6 species of marine invertebrates (California sea hare [Aplysia californica], purple sea urchin [Strongylocentrotus purpuratus], sunburst anemone [Anthopleura sola], knobby star [Pisaster giganteus], bat star [Asterina miniata], and brittle star [Ophiopteris papillosa]) with spontaneous copper toxicosis, 4 purple sea urchins with experimentally induced copper toxicosis, and 1 unexposed control of each species listed. The primary lesions in the California sea hare with copper toxicosis were branchial and nephridial necrosis. Affected echinoderms shared several histologic lesions, including epidermal necrosis and ulceration and increased numbers of coelomocytes within the water-vascular system. The sunburst anemone with copper toxicosis had necrosis of both epidermis and gastrodermis, as well as expulsion of zooxanthellae from the gastrodermis. In addition to the lesions attributed to copper toxicosis, our results describe normal microscopic features of these animals that may be useful for histopathologic assessment of marine invertebrates.

  13. Coastal Upwelling Drives Intertidal Assemblage Structure and Trophic Ecology

    PubMed Central

    Reddin, Carl J.; Docmac, Felipe; O’Connor, Nessa E.; Bothwell, John H.; Harrod, Chris

    2015-01-01

    Similar environmental driving forces can produce similarity among geographically distant ecosystems. Coastal oceanic upwelling, for example, has been associated with elevated biomass and abundance patterns of certain functional groups, e.g., corticated macroalgae. In the upwelling system of Northern Chile, we examined measures of intertidal macrobenthic composition, structure and trophic ecology across eighteen shores varying in their proximity to two coastal upwelling centres, in a hierarchical sampling design (spatial scales of >1 and >10 km). The influence of coastal upwelling on intertidal communities was confirmed by the stable isotope values (δ13C and δ15N) of consumers, including a dominant suspension feeder, grazers, and their putative resources of POM, epilithic biofilm, and macroalgae. We highlight the utility of muscle δ15N from the suspension feeding mussel, Perumytilus purpuratus, as a proxy for upwelling, supported by satellite data and previous studies. Where possible, we used corrections for broader-scale trends, spatial autocorrelation, ontogenetic dietary shifts and spatial baseline isotopic variation prior to analysis. Our results showed macroalgal assemblage composition, and benthic consumer assemblage structure, varied significantly with the intertidal influence of coastal upwelling, especially contrasting bays and coastal headlands. Coastal topography also separated differences in consumer resource use. This suggested that coastal upwelling, itself driven by coastline topography, influences intertidal communities by advecting nearshore phytoplankton populations offshore and cooling coastal water temperatures. We recommend the isotopic values of benthic organisms, specifically long-lived suspension feeders, as in situ alternatives to offshore measurements of upwelling influence. PMID:26214806

  14. In silico characterization of the neural alpha tubulin gene promoter of the sea urchin embryo Paracentrotus lividus by phylogenetic footprinting.

    PubMed

    Ragusa, Maria Antonietta; Longo, Valeria; Emanuele, Marco; Costa, Salvatore; Gianguzza, Fabrizio

    2012-03-01

    During Paracentrotus lividus sea urchin embryo development one alpha and one beta tubulin genes are expressed specifically in the neural cells and they are early end output of the gene regulatory network that specifies the neural commitment. In this paper we have used a comparative genomics approach to identify conserved regulatory elements in the P. lividus neural alpha tubulin gene. To this purpose, we have first isolated a genomic clone containing the entire gene plus 4.5 Kb of 5' upstream sequences. Then, we have shown by gene transfer experiments that its non-coding region drives the spatio-temporal gene expression corresponding substantially to that of the endogenous gene. In addition, we have identified by genome and EST sequence analysis the S. purpuratus alpha tubulin orthologous gene and we propose a revised annotation of some tubulin family members. Moreover, by computational techniques we delineate at least three putative regulatory regions located both in the upstream region and in the first intron containing putative binding sites for Forkhead and Nkx transcription factor families.

  15. Phylogenetic analysis and expression patterns of p16 and p19 in Paracentrotus lividus embryos.

    PubMed

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

    2012-07-01

    P16 and P19 are two small acidic proteins involved in the formation of the biomineralized skeleton of sea urchin embryos and adults. Here, we describe the cloning and the embryonic temporal and spatial expression profiles of p16 and p19 mRNAs, identified for the first time in Paracentrotus lividus. Phylogenetic analysis showed a high degree of similarity of the deduced Pl-P16 and Pl-P19 sequences with the Lytechinus variegatus and Strongylocentrotus purpuratus orthologs. While only a reduced similarity with other phyla, including mammals, was detected, their implication in biomineralized tissues calls for their conservation in evolution. By comparative quantitative PCR and in situ hybridization, we found that Pl-p16 and Pl-p19 expression was restricted to skeletogenic cells throughout embryogenesis, with transcript levels peaking at the late gastrula stage. Dissimilar Pl-p16 and Pl-p19 spatial expression within the primary mesenchyme cell syncytium at the gastrula and pluteus stages suggests the occurrence of a different regulation of gene transcription.

  16. Genotoxic and developmental effects in sea urchins are sensitive indicators of effects of genotoxic chemicals

    SciTech Connect

    Anderson, S.L. . Energy and Environment Division); Hose, J.E. . Dept. of Biology); Knezovich, J.P. . Health and Ecological Assessment Division)

    1994-07-01

    Purple sea urchin (Strongylocentrotus purpuratus) gametes and embryos were exposed to three known mutagenic chemicals (phenol, benzidine,and pentachlorophenol) over concentration ranges bracketing the effect levels for fertilization success. Normal development and cytogenetic effects (anaphase aberrations) were assessed after the cultures were allowed to develop for 48 h. Using radiolabeled chemicals, the authors also characterized concentrations in the test water as well as doses in the embryos following 2- and 48-h exposures. The authors observed dose responses for all chemicals and all responses, except for phenol, which showed no significant effect on development. Fertilization success was never the most sensitive end point. anaphase aberrations were the most sensitive response for phenol, with an LOEC of 2.5 mg/L exposure concentration. Anaphase aberrations and development were equivalent in sensitivity for benzidine within the tested dose range, and an LOEC of <0.1 mg/L was observed. Development was the most sensitive reasons for pentachlorophenol (LOEC 1 mg/L). the LOEC values for this study were generally lower than comparable data for aquatic life or human health protection. The authors conclude that genotoxicity and development evaluations should be included in environmental management applications and that tests developed primarily for human health protection do not reliably predict the effects of toxic substances on aquatic life.

  17. Control of protein synthesis in cell-free extracts of sea urchin embryos

    SciTech Connect

    Hansen, L.J.; Huang, W.I.; Jagus, R.

    1986-05-01

    Although the increase in protein synthesis that occurs after fertilization of sea urchin eggs results from increased utilization of stored maternal mRNA, the underlying mechanism is unknown. The authors have prepared cell-free extracts from S.purpuratus and A.puctulata unfertilized eggs and 2-cell embryos that retain the protein synthetic differences observed in vivo. The method is based on that of Dr. Alina Lopo. /sup 35/S methionine incorporation is linear during a 30 min incubation and is 10-20 fold higher in extracts from 2-cell embryos than unfertilized eggs. Addition of purified mRNA does not stimulate these systems, suggesting a regulatory mechanism other than mRNA masking. Addition of rabbit reticulocyte ribosomal salt wash stimulated protein synthesis in extracts from eggs but not embryos, suggesting deficiencies in translational components in unfertilized eggs. Mixing of egg and embryo lysates indicated the presence of a weak protein synthesis inhibitor in eggs. Translational control in developing sea urchin embryos thus appears to be complex, involving both stimulatory and inhibitory factors.

  18. Toxicity of sediments and interstitial waters form the Southern California Bight

    SciTech Connect

    Bay, S.; Greenstein, D.; Brown, J.; Jirik, A.

    1995-12-31

    The toxicity of 72 sediment samples collected during the EMAP Southern California Bight Pilot Project (SCBPP) was measured. Sediments from the mainland shelf between Point Conception and the Mexican border were collected from various depths and tested for toxicity using two methods. The toxicity of bulk sediment was measured using a 10-day amphipod (Ampelisca abdita) survival test. Interstitial water was also extracted from the samples and tested for toxicity using a 72-hour sea urchin (Strongylocentrotus purpuratus) embryo development test. Amphipod survival was high (> 80%) at all stations tested, although several sites near large sewage outfalls had statistically significant reductions in survival. No interference related to grain size variation was observed with the amphipod test. Most of the interstitial water samples produced abnormal sea urchin embryo development. Effects were not related to the presumed level of sediment contamination, but rather to ammonia concentration in virtually all cases. The impacts of sample handling procedures and ammonia on sediment toxicity data interpretation will be discussed.

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

    SciTech Connect

    Radha, A. V.; Forbes, Tori Z.; Killian, Christopher E.; Gilbert, P.U.P.A; Navrotsky, Alexandra

    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.

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

    SciTech Connect

    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.

  1. Biological testing of sediment for the Olympia Harbor Navigation Improvement Project, 1988: Geoduck, amphipod, and echinoderm bioassays

    SciTech Connect

    Ward, J.A.; Word, J.Q.; Antrim, L.D.

    1989-05-01

    The Olympia Harbor Navigation Improvement Project requires the dredging of approximately 330,000 cubic yards (cy) of sediment from the harbor entrance channel and 205,185 cy from the turning basin. Puget Sound Dredged Disposal Analysis (PSDDA) partial characterization studies were used to plan a full sediment characterization in which chemical analyses and biological testing of sediments evaluated the suitability of the dredged material for unconfined, open-water disposal. The US Army Corps of Engineers (COE), Seattle District, contracted with NOAA/NMFS, Environmental Conservation Division, to perform the chemical analysis and Microtox bioassay tests, and with the Battelle/Marine Sciences Laboratory (MSL) in Sequim to perform flow-through solid-phase bioassays utilizing juvenile (8 to 10 mm) geoduck clams, Panopea generosa, and static solid phase bioassays using the phoxocephalid amphipod, Rhepoxynius abronius, developing embryos and gametes of the purple sea urchin, Strongylocentrotus purpuratus, and the larvae of the Pacific oyster Crassostrea gigas. When the results of the biological tests were evaluated under PSDDA guidelines, it was found that all the tested sediment treatments from Olympia Harbor are suitable for unconfined open-water disposal. 14 refs., 12 figs., 3 tabs.

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

    PubMed

    Romero, A; Novoa, B; Figueras, A

    2016-09-01

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

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

    PubMed

    Landrum, P F; Crosby, D G

    1981-05-01

    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.

  4. Complete sequence of the mitochondrial DNA in the sea urchin Arbacia lixula: conserved features of the echinoid mitochondrial genome.

    PubMed

    De Giorgi, C; Martiradonna, A; Lanave, C; Saccone, C

    1996-04-01

    The complete nucleotide sequence (15,719 nucleotides) of the mitochondrial DNA (mtDNA) from the sea urchin Arbacia lixula is presented. The comparison of gene arrangement between different echinoderm orders of the same class provides evidence that the gene organization is conserved within the same echinoderm class. The peculiarities of sea urchin mtDNA features, already described, are confirmed by the A. lixula mtDNA sequence. The comparison of the entire sequences of mtDNA among A. lixula, Paracentrotus lividus, and Strongylocentrotus purpuratus allowed us to detect peculiar features, common to the three sea urchin species, that can represent the molecular signature of the mt genome in the sea urchin group. Analysis of the nucleotide composition indicates that A. lixula mtDNA, in contrast with the mtDNA of other sea urchins, shows a bias in the use of T and tends to avoid the use of C, most evident in the neutral part of the molecule, such as the third codon positions. This observation indicates that the three sea urchin mtDNAs evolve under different mutation pressure. Analysis of the sequence evolution allowed us to confirm the phylogenetic tree. However, the absolute divergence time, calculated on the basis of paleontological estimates, largely diverged from the expected one.

  5. Intrinsic hierarchical structural imperfections in a natural ceramic of bivalve shell with distinctly graded properties

    PubMed Central

    Jiao, Da; Liu, Zengqian; Zhang, Zhenjun; Zhang, Zhefeng

    2015-01-01

    Despite the extensive investigation on the structure of natural biological materials, insufficient attention has been paid to the structural imperfections by which the mechanical properties of synthetic materials are dominated. In this study, the structure of bivalve Saxidomus purpuratus shell has been systematically characterized quantitatively on multiple length scales from millimeter to sub-nanometer. It is revealed that hierarchical imperfections are intrinsically involved in the crossed-lamellar structure of the shell despite its periodically packed platelets. In particular, various favorable characters which are always pursued in synthetic materials, e.g. nanotwins and low-angle misorientations, have been incorporated herein. The possible contributions of these imperfections to mechanical properties are further discussed. It is suggested that the imperfections may serve as structural adaptations, rather than detrimental defects in the real sense, to help improve the mechanical properties of natural biological materials. This study may aid in understanding the optimizing strategies of structure and properties designed by nature, and accordingly, provide inspiration for the design of synthetic materials. PMID:26198844

  6. Transcriptional and post-transcriptional regulation of histone variant H2A.Z during sea urchin development.

    PubMed

    Hajdu, Mihai; Calle, Jasmine; Puno, Andrea; Haruna, Aminat; Arenas-Mena, César

    2016-12-01

    Histone variant H2A.Z promotes chromatin accessibility at transcriptional regulatory elements and is developmentally regulated in metazoans. We characterize the transcriptional and post-transcriptional regulation of H2A.Z in the purple sea urchin Strongylocentrotus purpuratus. H2A.Z depletion by antisense translation-blocking morpholino oligonucleotides during early development causes developmental collapse, in agreement with its previously demonstrated general role in transcriptional multipotency. During H2A.Z peak expression in 24-h embryos, endogenous H2A.Z 3' UTR sequences stabilize GFP mRNAs relative to those with SV40 3' UTR sequences, although the 3' UTR of H2A.Z does not determine the spatial distribution of H2A.Z transcripts during embryonic and postembryonic development. We elaborated an H2A.Z::GFP BAC reporter that reproduces embryonic H2A.Z expression. Genome-wide chromatin accessibility analysis using ATAC-seq revealed a cis-regulatory module (CRM) that, when deleted, causes a significant decline of the H2A.Z reporter expression. In addition, the mutation of a Sox transcription factor binding site motif and, more strongly, of a Myb motif cause significant decline of reporter gene expression. Our results suggest that an undetermined Myb-family transcription factor controls the transcriptional regulation of H2A.Z.

  7. A calcium-binding, asparagine-linked oligosaccharide is involved in skeleton formation in the sea urchin embryo

    PubMed Central

    1989-01-01

    We have previously identified a 130-kD cell surface protein that is involved in calcium uptake and skeleton formation by gastrula stage embryos of the sea urchin Strongylocentrotus purpuratus (Carson et al., 1985. Cell. 41:639-648). A monoclonal antibody designated mAb 1223 specifically recognizes the 130-kD protein and inhibits Ca+2 uptake and growth of the CaCO3 spicules produced by embryonic primary mesenchyme cells cultured in vitro. In this report, we demonstrate that the epitope recognized by mAb 1223 is located on an anionic, asparagine- linked oligosaccharide chain on the 130-kD protein. Combined enzymatic and chemical treatments indicate that the 1223 oligosaccharide contains fucose and sialic acid that is likely to be O-acetylated. Moreover, we show that the oligosaccharide chain containing the 1223 epitope specifically binds divalent cations, including Ca+2. We propose that one function of this negatively charged oligosaccharide moiety on the surfaces of primary mesenchyme cells is to facilitate binding and sequestration of Ca+2 ions from the blastocoelic fluid before internalization and subsequent deposition into the growing CaCO3 skeleton. PMID:2475510

  8. High-Density Genetic Mapping with Interspecific Hybrids of Two Sea Urchins, Strongylocentrotus nudus and S. intermedius, by RAD Sequencing

    PubMed Central

    Dong, Ying; Gao, Shan; Chen, Zhong; Jiang, Jingwei; Yang, Aifu; Sun, Hongjuan; Guan, Xiaoyan; Jiang, Bei; Wang, Bai

    2015-01-01

    Sea urchins have long been used as research model organisms for developmental biology and evolutionary studies. Some of them are also important aquaculture species in East Asia. In this work, we report the construction of RAD-tag based high-density genetic maps by genotyping F1 interspecific hybrids derived from a crossing between a female sea urchin Strongylocentrotus nudus and a male Strongylocentrotus intermedius. With polymorphisms present in these two wild individuals, we constructed a female meiotic map containing 3,080 markers for S. nudus, and a male meiotic map for S. intermedius which contains 1,577 markers. Using the linkage maps, we were able to anchor a total of 1,591 scaffolds (495.9 Mb) accounting for 60.8% of the genome assembly of Strongylocentrotus purpuratus. A genome-wide scan resulted in the identification of one putative QTL for body size which spanned from 25.3 cM to 30.3 cM. This study showed the efficiency of RAD-Seq based high-density genetic map construction using F1 progenies for species with no prior genomic information. The genetic maps are essential for QTL mapping and are useful as framework to order and orientate contiguous scaffolds from sea urchin genome assembly. The integration of the genetic map with genome assembly would provide an unprecedented opportunity to conduct QTL analysis, comparative genomics, and population genetics studies. PMID:26398139

  9. Coastal Upwelling Drives Intertidal Assemblage Structure and Trophic Ecology.

    PubMed

    Reddin, Carl J; Docmac, Felipe; O'Connor, Nessa E; Bothwell, John H; Harrod, Chris

    2015-01-01

    Similar environmental driving forces can produce similarity among geographically distant ecosystems. Coastal oceanic upwelling, for example, has been associated with elevated biomass and abundance patterns of certain functional groups, e.g., corticated macroalgae. In the upwelling system of Northern Chile, we examined measures of intertidal macrobenthic composition, structure and trophic ecology across eighteen shores varying in their proximity to two coastal upwelling centres, in a hierarchical sampling design (spatial scales of >1 and >10 km). The influence of coastal upwelling on intertidal communities was confirmed by the stable isotope values (δ13C and δ15N) of consumers, including a dominant suspension feeder, grazers, and their putative resources of POM, epilithic biofilm, and macroalgae. We highlight the utility of muscle δ15N from the suspension feeding mussel, Perumytilus purpuratus, as a proxy for upwelling, supported by satellite data and previous studies. Where possible, we used corrections for broader-scale trends, spatial autocorrelation, ontogenetic dietary shifts and spatial baseline isotopic variation prior to analysis. Our results showed macroalgal assemblage composition, and benthic consumer assemblage structure, varied significantly with the intertidal influence of coastal upwelling, especially contrasting bays and coastal headlands. Coastal topography also separated differences in consumer resource use. This suggested that coastal upwelling, itself driven by coastline topography, influences intertidal communities by advecting nearshore phytoplankton populations offshore and cooling coastal water temperatures. We recommend the isotopic values of benthic organisms, specifically long-lived suspension feeders, as in situ alternatives to offshore measurements of upwelling influence.

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

    SciTech Connect

    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.

  11. Cis-regulatory analysis of the sea urchin pigment cell gene polyketide synthase.

    PubMed

    Calestani, Cristina; Rogers, David J

    2010-04-15

    The Strongylocentrotus purpuratus polyketide synthase gene (SpPks) encodes an enzyme required for the biosynthesis of the larval pigment echinochrome. SpPks is expressed exclusively in pigment cells and their precursors starting at blastula stage. The 7th-9th cleavage Delta-Notch signaling, required for pigment cell development, positively regulates SpPks. In previous studies, the transcription factors glial cell missing (SpGcm), SpGatae and kruppel-like (SpKrl/z13) have been shown to positively regulate SpPks. To uncover the structure of the Gene Regulatory Network (GRN) regulating the specification and differentiation processes of pigment cells, we experimentally analyzed the putative SpPks cis-regulatory region. We established that the -1.5kb region is sufficient to recapitulate the correct spatial and temporal expression of SpPks. Predicted DNA-binding sites for SpGcm, SpGataE and SpKrl are located within this region. The mutagenesis of these DNA-binding sites indicated that SpGcm, SpGataE and SpKrl are direct positive regulators of SpPks. These results demonstrate that the sea urchin GRN for pigment cell development is quite shallow, which is typical of type I embryo development.

  12. Phylogenomic resolution of the hemichordate and echinoderm clade.

    PubMed

    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.

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

    PubMed

    Jurgens, Laura J; Rogers-Bennett, Laura; Raimondi, Peter T; Schiebelhut, Lauren M; Dawson, Michael N; Grosberg, Richard K; Gaylord, Brian

    2015-01-01

    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.

  14. A novel fatty acid-binding protein-like carotenoid-binding protein from the gonad of the New Zealand sea urchin Evechinus chloroticus.

    PubMed

    Pilbrow, Jodi; Sabherwal, Manya; Garama, Daniel; Carne, Alan

    2014-01-01

    A previously uncharacterized protein with a carotenoid-binding function has been isolated and characterized from the gonad of the New Zealand sea urchin Evechinus chloroticus. The main carotenoid bound to the protein was determined by reversed phase-high performance liquid chromatography to be 9'-cis-echinenone and hence this 15 kDa protein has been called an echinenone-binding protein (EBP). Purification of the EBP in quantity from the natural source proved to be challenging. However, analysis of EBP by mass spectrometry combined with information from the Strongylocentrotus purpuratus genome sequence and the recently published E. chloroticus transcriptome database, enabled recombinant expression of wild type EBP and also of a cysteine61 to serine mutant that had improved solubility characteristics. Circular dichroism data and ab initio structure prediction suggests that the EBP adopts a 10-stranded β-barrel fold consistent with that of fatty acid-binding proteins. Therefore, EBP may represent the first report of a fatty acid-binding protein in complex with a carotenoid.

  15. A Novel Fatty Acid-Binding Protein-Like Carotenoid-Binding Protein from the Gonad of the New Zealand Sea Urchin Evechinus chloroticus

    PubMed Central

    Pilbrow, Jodi; Sabherwal, Manya; Garama, Daniel; Carne, Alan

    2014-01-01

    A previously uncharacterized protein with a carotenoid-binding function has been isolated and characterized from the gonad of the New Zealand sea urchin Evechinus chloroticus. The main carotenoid bound to the protein was determined by reversed phase-high performance liquid chromatography to be 9′-cis-echinenone and hence this 15 kDa protein has been called an echinenone-binding protein (EBP). Purification of the EBP in quantity from the natural source proved to be challenging. However, analysis of EBP by mass spectrometry combined with information from the Strongylocentrotus purpuratus genome sequence and the recently published E. chloroticus transcriptome database, enabled recombinant expression of wild type EBP and also of a cysteine61 to serine mutant that had improved solubility characteristics. Circular dichroism data and ab initio structure prediction suggests that the EBP adopts a 10-stranded β-barrel fold consistent with that of fatty acid-binding proteins. Therefore, EBP may represent the first report of a fatty acid-binding protein in complex with a carotenoid. PMID:25192378

  16. Proteomic responses of sea urchin embryos to stressful ultraviolet radiation.

    PubMed

    Adams, N L; Campanale, J P; Foltz, K R

    2012-11-01

    Solar ultraviolet radiation (UVR, 290-400 nm) penetrates into seawater and can harm shallow-dwelling and planktonic marine organisms. Studies dating back to the 1930s revealed that echinoids, especially sea urchin embryos, are powerful models for deciphering the effects of UVR on embryonic development and how embryos defend themselves against UV-induced damage. In addition to providing a large number of synchronously developing embryos amenable to cellular, biochemical, molecular, and single-cell analyses, the purple sea urchin, Strongylocentrotus purpuratus, also offers an annotated genome. Together, these aspects allow for the in-depth study of molecular and biochemical signatures of UVR stress. Here, we review the effects of UVR on embryonic development, focusing on the early-cleavage stages, and begin to integrate data regarding single-protein responses with comprehensive proteomic assessments. Proteomic studies reveal changes in levels of post-translational modifications to proteins that respond to UVR, and identify proteins that can then be interrogated as putative targets or components of stress-response pathways. These responsive proteins are distributed among systems upon which targeted studies can now begin to be mapped. Post-transcriptional and translational controls may provide early embryos with a rapid, fine-tuned response to stress during early stages, especially during pre-blastula stages that rely primarily on maternally derived defenses rather than on responses through zygotic gene transcription.

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

    SciTech Connect

    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.

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

    SciTech Connect

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

    2005-10-11

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

  19. Signals of selection in outlier loci in a widely dispersing species across an environmental mosaic.

    PubMed

    Pespeni, Melissa H; Palumbi, Stephen R

    2013-07-01

    Local adaptation reflects a balance between natural selection and gene flow and is classically thought to require the retention of locally adapted alleles. However, organisms with high dispersal potential across a spatially or temporally heterogeneous landscape pose an interesting challenge to this view requiring local selection every generation or when environmental conditions change to generate adaptation in adults. Here, we test for geographical and sequence-based signals of selection in five putatively adaptive and two putatively neutral genes identified in a previous genome scan of the highly dispersing purple sea urchin, Strongylocentrotus purpuratus. Comparing six populations spanning the species' wide latitudinal range from Canada to Baja California, Mexico, we find positive tests for selection in the putative adaptive genes and not in the putative neutral genes. Specifically, we find an excess of low-frequency and nonsynonymous polymorphisms in two transcription factors and a transporter protein, and an excess of common amino acid polymorphisms in the two transcription factors, suggestive of spatially balancing selection. We test for a genetic correlation with temperature, a dominant environmental variable in this coastal ecosystem. We find mild clines and a stronger association of genetic variation with temperature than latitude in four of the five putative adaptive loci and a signal of local adaptation in the Southern California Bight. Overall, patterns of genetic variation match predictions based on spatially or temporally balancing selection in a heterogeneous landscape and illustrate the value of geographical and coalescent tests on candidate loci identified in a genome-wide scan for selection.

  20. A Method for Microinjection of Patiria minata Zygotes

    PubMed Central

    Cheatle Jarvela, Alys M.; Hinman, Veronica

    2014-01-01

    Echinoderms have long been a favorite model system for studies of reproduction and development, and more recently for the study of gene regulation and evolution of developmental processes. The sea star, Patiria miniata, is gaining prevalence as a model system for these types of studies which were previously performed almost exclusively in the sea urchins, Strongylocentrotus purpuratus and Lytechinus variegatus. An advantage of these model systems is the ease of producing modified embryos in which a particular gene is up or downregulated, labeling a group of cells, or introducing a reporter gene. A single microinjection method is capable of creating a wide variety of such modified embryos. Here, we present a method for obtaining gametes from P. miniata, producing zygotes, and introducing perturbing reagents via microinjection. Healthy morphant embryos are subsequently isolated for quantitative and qualitative studies of gene function. The availability of genome and transcriptome data for this organism has increased the types of studies that are performed and the ease of executing them. PMID:25226153

  1. [Evolutional principles of homology in regulatory genes of myogenesis].

    PubMed

    Ozerniuk, I D; Miuge, N S

    2012-01-01

    Analysis of early steps in muscular system development of invertebrates and vertebrates shows that early steps of myogenesis are regulated by genes-orthologs mainly belonging to two families, Pax and bHLH. In the majority of the following organisms, muscles formation (steps of determination and the earliest steps of myogenesis) is regulated by genes orthologs Pax3 which belong to the family Pax: nematodes (Caenorhabditis elegans, Pristionchus pacificus), insects (Drosophila melanogaster), echinoderms (Strongylocentrotus purpuratus), sea squirts (Ciona intestinalis, Holocynthia roretzi), fishes (Danio rerio), amphibians (Xenopus laevis), birds, and mammals (mouse, rat). The nematode C. elegans is an exception since formation of its muscles in this period is regulated by homeobox gene Pal-1 belonging to the family Caudal. The sea squirt C. intestinalis is also an exception because the earliest steps of development involved in further muscle formation are accompanied by activation of the gene CiSna (snail) (gene family basic Zinc finger). The next steps of myogenesis in all analyzed species are regulated by genes orthologs belonging to the family of transcriptional factors bHLH. They along with genes Pax3 are characterized by a high extent of homology in all studied groups of animals.

  2. A method for microinjection of Patiria miniata zygotes.

    PubMed

    Cheatle Jarvela, Alys M; Hinman, Veronica

    2014-09-01

    Echinoderms have long been a favorite model system for studies of reproduction and development, and more recently for the study of gene regulation and evolution of developmental processes. The sea star, Patiria miniata, is gaining prevalence as a model system for these types of studies which were previously performed almost exclusively in the sea urchins, Strongylocentrotus purpuratus and Lytechinus variegatus. An advantage of these model systems is the ease of producing modified embryos in which a particular gene is up or downregulated, labeling a group of cells, or introducing a reporter gene. A single microinjection method is capable of creating a wide variety of such modified embryos. Here, we present a method for obtaining gametes from P. miniata, producing zygotes, and introducing perturbing reagents via microinjection. Healthy morphant embryos are subsequently isolated for quantitative and qualitative studies of gene function. The availability of genome and transcriptome data for this organism has increased the types of studies that are performed and the ease of executing them.

  3. The Insect Chemoreceptor Superfamily Is Ancient in Animals.

    PubMed

    Robertson, Hugh M

    2015-11-01

    The insect chemoreceptor superfamily consists of 2 gene families, the highly diverse gustatory receptors (GRs) found in all arthropods with sequenced genomes and the odorant receptors that evolved from a GR lineage and have been found only in insects to date. Here, I describe relatives of the insect chemoreceptor superfamily, specifically the basal GR family, in diverse other animals, showing that the superfamily dates back at least to early animal evolution. GR-Like (GRL) genes are present in the genomes of the placozoan Trichoplax adhaerens, an anemone Nematostella vectensis, a coral Acropora digitifera, a polychaete Capitella teleta, a leech Helobdella robusta, the nematode Caenorhabditis elegans (and many other nematodes), 3 molluscs (a limpet Lottia gigantea, an oyster Crassostrea gigas, and the sea hare Aplysia californica), the sea urchin Strongylocentrotus purpuratus, and the sea acorn Saccoglossus kowalevskii. While some of these animals contain multiple divergent GRL lineages, GRLs have been lost entirely from other animal lineages such as vertebrates. GRLs are absent from the ctenophore Mnemiopsis leidyi, the demosponge Amphimedon queenslandica, and 2 available chaonoflagellate genomes, so it remains unclear whether this superfamily originated before or during animal evolution.

  4. The echinoderm adhesome

    PubMed Central

    Whittaker, Charles A.; Bergeron, Karl-Frederik; Whittle, James; Brandhorst, Bruce P.; Burke, Robert D.; Hynes, Richard O.

    2013-01-01

    Although the development of sea urchin embryos has been studied extensively and clearly involves both cell adhesion and cell migration, rather little is known about the adhesion receptors and extracellular matrix molecules involved. The completion of the genome of Strongylocentrotus purpuratus allows a comprehensive survey of the complement of cell-cell and cell-matrix adhesion molecules in this organism. Furthermore, the phylogenetic position of echinoderms offers the opportunity to compare the complement of adhesion proteins between protostome and deuterostome invertebrates and between invertebrate and vertebrate deuterostomes. Many aspects of development and cell interactions differ among these different taxa and it is likely that analysis of the spectrum of adhesion receptors and extracellular matrix proteins can open up new insights into which molecules have evolved to suit particular developmental processes. In this paper, we report the results of an initial analysis along these lines. The echinoderm adhesome (complement of adhesion-related genes/proteins) is similar overall to that of other invertebrates although there are significant deuterostome-specific innovations and some interesting features previously thought to be chordate- or vertebrate-specific. PMID:16950242

  5. Respiratory burst oxidase of fertilization.

    PubMed Central

    Heinecke, J W; Shapiro, B M

    1989-01-01

    Partially reduced oxygen species are toxic, yet sea urchin eggs synthesize H2O2 in a "respiratory burst" at fertilization, as an extracellular oxidant to crosslink their protective surface envelopes. To study the biochemical mechanism for H2O2 production, we have isolated an NADPH-specific oxidase fraction from homogenates of unfertilized Strongylocentrotus purpuratus eggs that produces H2O2 when stimulated with Ca2+ and MgATP2-. Concentrations of free Ca2+ previously implicated in regulation of egg activation modulate the activity of the oxidase. Inhibitors were used to test the relevance of this oxidase to the respiratory burst of fertilization. Procaine, two phenothiazines, and N-ethylmaleimide (but not iodoacetamide) inhibited H2O2 production by the oxidase fraction and oxygen consumption by activated eggs. The ATP requirement suggested that protein kinase activity might regulate the respiratory burst of fertilization; consonant with this hypothesis, H-7 and staurosporine were inhibitory. The respiratory burst oxidase of fertilization is an NADPH:O2 oxidoreductase that appears to be regulated by a protein kinase; although it bears a remarkable resemblance to the neutrophil oxidase, unlike the latter it does not form O2- as its initial product. PMID:2537493

  6. Egg jelly induces the phosphorylation of histone H3 in spermatozoa of the sea urchin Arbacia punctulata.

    PubMed

    Vacquier, V D; Porter, D C; Keller, S H; Aukerman, M

    1989-05-01

    When spermatozoa of Arbacia punctulata are labeled with 32P and treated with soluble egg jelly, radiolabel is incorporated into histone H3. The time course of labeling correlates with the period of chromatin decondensation of sperm pronuclei in eggs. Phosphorylation is on serine and may result from increased turnover of phosphate on H3. The macromolecular fraction of egg jelly (and not the peptide fraction) is the inducer of H3 phosphorylation. The reaction is dependent on external Ca2+ and is induced by monensin and A23187. H3 phosphorylation is not induced by the phosphodiesterase inhibitor IBMX and relatively high (250 microM) concentrations of the protein kinase inhibitor H8 are needed to block the reaction, suggesting that it is cAMP independent. A surprising finding is that merely diluting the cells into Na+ free media is the most effective method to induce the radiolabeling of H3. These results are in contrast to findings on the egg jelly induced phosphorylation of histone H1 in S. purpuratus spermatozoa. These species differences must reflect the great evolutionary divergence between these two sea urchin species in the mechanism of regulation of the phosphorylation of nuclear proteins during fertilization.

  7. Na+/K+-ATPase activity during early development and growth of an Antarctic sea urchin.

    PubMed

    Leong, P K; Manahan, D T

    1999-08-01

    In Antarctic environments, the physiological bases for long larval life spans under natural conditions of limited food availability are not understood. The Na+ pump is likely to be involved with hypometabolic regulation in such cold environments. Changes in the activity and metabolic importance of Na+/K+-ATPase were measured in embryos of the Antarctic sea urchin Sterechinus neumayeri and in larvae reared under different feeding conditions. The rate of increase of total Na+/K+-ATPase activity was 3.9 times faster in fed than in unfed larvae. During development and growth, there was an increase in the percentage of total, potential Na+/K+-ATPase activity that was physiologically utilized. In early (10-day-old) gastrulae, 17 % was utilized in vivo, increasing to 77 % in six-arm pluteus (48-day-old) larvae. The metabolic importance of in vivo Na+/K+-ATPase activity also increased during development, accounting for 12 % of metabolic rate at day 10 and 84 % at day 48. When compared at the same enzyme assay temperature (15 degrees C), the protein-specific total Na+/K+-ATPase activities for late embryonic (prism) and early larval (pluteus) stages of S. neumayeri were 2.6 times lower than those for comparable developmental stages of two temperate sea urchin species (Strongylocentrotus purpuratus and Lytechinus pictus).

  8. Expression of the Hox gene complex in the indirect development of a sea urchin.

    PubMed

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

    1998-10-27

    Hox complex genes control spatial patterning mechanisms in the development of arthropod and vertebrate body plans. Hox genes are all expressed during embryogenesis in these groups, which are all directly developing organisms in that embryogenesis leads at once to formation of major elements of the respective adult body plans. In the maximally indirect development of a large variety of invertebrates, the process of embryogenesis leads only to a free-living, bilaterally organized feeding larva. Maximal indirect development is exemplified in sea urchins. The 5-fold radially symmetric adult body plan of the sea urchin is generated long after embryogenesis is complete, by a separate process occurring within imaginal tissues set aside in the larva. The single Hox gene complex of Strongylocentrotus purpuratus contains 10 genes, and expression of eight of these genes was measured by quantitative methods during both embryonic and larval developmental stages and also in adult tissues. Only two of these genes are used significantly during the entire process of embryogenesis per se, although all are copiously expressed during the stages when the adult body plan is forming in the imaginal rudiment. They are also all expressed in various combinations in adult tissues. Thus, development of a microscopic, free-living organism of bilaterian grade, the larva, does not appear to require expression of the Hox gene cluster as such, whereas development of the adult body plan does. These observations reflect on mechanisms by which bilaterian metazoans might have arisen in Precambrian evolution.

  9. Rho-kinase in sea urchin eggs and embryos.

    PubMed

    Aguirre-Armenta, Beatriz; López-Godínez, Juana; Martínez-Cadena, Guadalupe; García-Soto, Jesús

    2011-06-01

    The activation of sea urchin eggs at fertilization provides an ideal system for studying the molecular events involved in cellular activation. Rho GTPases, which are key signaling enzymes in eukaryotes, are involved in sustaining the activation of sea urchin eggs; however, their downstream effectors have not yet been characterized. In somatic cells, RhoA regulates a serine/threonine kinase known as Rho-kinase (ROCK). The activity of ROCK in early sea urchin development has been inferred, but not tested directly. A ROCK gene was identified in the sea urchin (Strongylocentrotus purpuratus) genome and the sequence of its cDNA determined. The sea urchin ROCK (SpROCK) sequence predicts a protein of 158 kDa with >72% and 45% identities with different protein orthologues of the kinase catalytic domain and the complete protein sequence, respectively. SpROCK mRNA levels are high in unfertilized eggs and decrease to 35% after 15 min postfertilization and remain low up to the 4 cell stage. Antibodies to the human ROCK-I kinase domain revealed SpROCK to be concentrated in the cortex of eggs and early embryos. Co-immunoprecipitation assays indicate that RhoA and SpROCK are physically associated. This association is destroyed by treatment with the C3 exoenzyme and with the ROCK antagonist H-1152. H-1152 also inhibited DNA synthesis in embryos. We conclude that the Rho-dependent signaling pathway, via SpROCK, is essential for early embryonic development.

  10. Turbulent shear spurs settlement in larval sea urchins.

    PubMed

    Gaylord, Brian; Hodin, Jason; Ferner, Matthew C

    2013-04-23

    Marine invertebrates commonly produce larvae that disperse in ocean waters before settling into adult shoreline habitat. Chemical and other seafloor-associated cues often facilitate this latter transition. However, the range of effectiveness of such cues is limited to small spatial scales, creating challenges for larvae in finding suitable sites at which to settle, especially given that they may be carried many kilometers by currents during their planktonic phase. One possible solution is for larvae to use additional, broader-scale environmental signposts to first narrow their search to the general vicinity of a candidate settlement location. Here we demonstrate strong effects of just such a habitat-scale cue, one with the potential to signal larvae that they have arrived in appropriate coastal areas. Larvae of the purple sea urchin (Strongylocentrotus purpuratus) exhibit dramatic enhancement in settlement following stimulation by turbulent shear typical of wave-swept shores where adults of this species live. This response manifests in an unprecedented fashion relative to previously identified cues. Turbulent shear does not boost settlement by itself. Instead, it drives a marked developmental acceleration that causes "precompetent" larvae refractory to chemical settlement inducers to immediately become "competent" and thereby reactive to such inducers. These findings reveal an unrecognized ability of larval invertebrates to shift the trajectory of a major life history event in response to fluid-dynamic attributes of a target environment. Such an ability may improve performance and survival in marine organisms by encouraging completion of their life cycle in advantageous locations.

  11. Early development and neurogenesis of Temnopleurus reevesii.

    PubMed

    Yaguchi, Shunsuke; Yamazaki, Atsuko; Wada, Wakana; Tsuchiya, Yasutaka; Sato, Toshihiko; Shinagawa, Hideo; Yamada, Yutaro; Yaguchi, Junko

    2015-04-01

    Sea urchins are model non-chordate deuterostomes, and studying the nervous system of their embryos can aid in the understanding of the universal mechanisms of neurogenesis. However, despite the long history of sea urchin embryology research, the molecular mechanisms of their neurogenesis have not been well investigated, in part because neurons appear relatively late during embryogenesis. In this study, we used the species Temnopleurus reevesii as a new sea urchin model and investigated the detail of its development and neurogenesis during early embryogenesis. We found that the embryos of T. reevesii were tolerant of high temperatures and could be cultured successfully at 15-30°C during early embryogenesis. At 30°C, the embryos developed rapidly enough that the neurons appeared at just after 24 h. This is faster than the development of other model urchins, such as Hemicentrotus pulcherrimus or Strongylocentrotus purpuratus. In addition, the body of the embryo was highly transparent, allowing the details of the neural network to be easily captured by ordinary epifluorescent and confocal microscopy without any additional treatments. Because of its rapid development and high transparency during embryogenesis, T. reevesii may be a suitable sea urchin model for studying neurogenesis. Moreover, the males and females are easily distinguishable, and the style of early cleavages is intriguingly unusual, suggesting that this sea urchin might be a good candidate for addressing not only neurology but also cell and developmental biology.

  12. Utilization of the aquatic research facility and fertilization syringe unit to study sea urchin development in space.

    PubMed

    Schatten, H; Chakrabarti, A; Levine, H G; Anderson, K

    1999-10-01

    Methods were developed for the investigation of the effects of microgravity on early development in sea urchins within the Canadian Space Agency's Aquatic Research Facility (ARF). The ARF payload provided light, temperature control, automated fixation capability, and a 1 G on-orbit centrifuge control. Eggs and embryos of either the sea urchin species Lytechinus pictus or Strongylocentrotus purpuratus were loaded into Standard Container Assemblies (SCAs) which comprised the experimental aquaria (33 mL volume) contained within the ARF. A newly developed Fertilization Syringe Unit (FSU) was used to achieve "in-flight" fertilization capability. Fixative solutions were preloaded into fixation blocks maintained adjacent to the SCAs and injected at pre-selected time points, resulting in final (diluted) concentrations of either 0.5% or 2% glutaraldehyde (depending upon embryonic stage). Light, scanning, and transmission electron microscopy determined that all desired embryonic and cell division stages (16-cell stage, blastula, gastrula, and pluteus) were preserved using the experimental protocols and fixation capability provided by the ARF/FSU system.

  13. Characterization and expression of two matrix metalloproteinase genes during sea urchin development.

    PubMed

    Ingersoll, Eric P; Pendharkar, Ninad C

    2005-08-01

    Matrix metalloproteinases (MMPs) play an essential role in a variety of processes in development that require extracellular matrix remodeling and degradation. In this study, we characterize two MMPs from the sea urchin Strongylocentrotus purpuratus. These clones can both be identified as MMPs based on the presence of conserved domains such as the cysteine switch, zinc-binding, and hemopexin domains. In addition, both of these genes contain consensus furin cleavage sites and putative transmembrane domains, classifying them as membrane-type MMPs. We have named these clones SpMMP14 and SpMMP16 based on the vertebrate MMPs with which they share the greatest similarity. SpMMP14 is expressed in all cells from the egg to mesenchyme blastula stage embryo. Expression of this gene is strongest in the animal and vegetal poles early in gastrulation and in the animal pole only later in gastrulation. SpMMP16 is expressed at low levels in eggs. Expression of SpMMP16 becomes more pronounced in the vegetal pole region at the blastula and mesenchyme blastula stages and becomes confined to vegetal pole descendants, such as pigment cells, later in development. In the future, we hope to learn more about the possible functions of these genes in sea urchin development.

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    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.

  17. Phylogeny and development of marine model species: strongylocentrotid sea urchins.

    PubMed

    Biermann, Christiane H; Kessing, Bailey D; Palumbi, Stephen R

    2003-01-01

    The phylogenetic relationships of ten strongy-locentrotid sea urchin species were determined using mitochondrial DNA sequences. This phylogeny provides a backdrop for the evolutionary history of one of the most studied groups of sea urchins. Our phylogeny indicates that a major revision of this group is in order. All else remaining unchanged, it supports the inclusion of three additional species into the genus Strongylocentrotus (Hemicentrotus pulcherrimus, Allocentrotus fragilis, and Pseudocentrotus depressus). All were once thought to be closely related to this genus, but subsequent revisions separated them into other taxonomic groupings. Most strongylocentrotid species are the result of a recent burst of speciation in the North Pacific that resulted in an ecological diversification. There has been a steady reduction in the complexity of larval skeletons during the expansion of this group. Gamete attributes like egg size, on the other hand, are not correlated with phylogenetic position. In addition, our results indicate that the rate of replacement substitutions is highly variable among phylogenetic lineages. The branches leading to S. purpuratus and S. franciscanus were three to six times longer than those leading to closely related species.

  18. Regulation of spblimp1/krox1a, an alternatively transcribed isoform expressed in midgut and hindgut of the sea urchin gastrula.

    PubMed

    Livi, Carolina B; Davidson, Eric H

    2007-01-01

    The sea urchin regulatory gene Spblimp1/krox produces alternatively transcribed and spliced isoforms, 1a and 1b, which have different temporal and spatial patterns of expression. Here we describe a cis-regulatory module that controls the expression of the 1a splice form in the midgut and hindgut at the beginning of gastrulation. Conserved sequence patches revealed by a comparison of the blimp1/krox locus in Strongylocentrotus purpuratus and Lytechinus variegatus genomes were tested by gene transfer, in association with GFP or CAT reporter genes. An expression construct containing a conserved sequence patch immediately 5' of exon 1a included the transcription initiation site for blimp1/krox1a. This construct displays specific mid and hindgut expression, indicating that these are the locations of endogenous blimp1/krox1a transcription during the gastrula stage. Its sequence contains binding sites for Brn1/2/4, Otx, and Blimp1/Krox itself, as predicted in a prior regulatory network analysis.

  19. CO2 induced seawater acidification impacts sea urchin larval development I: elevated metabolic rates decrease scope for growth and induce developmental delay.

    PubMed

    Stumpp, M; Wren, J; Melzner, F; Thorndyke, M C; Dupont, S T

    2011-11-01

    Anthropogenic CO(2) emissions are acidifying the world's oceans. A growing body of evidence is showing that ocean acidification impacts growth and developmental rates of marine invertebrates. Here we test the impact of elevated seawater pCO(2) (129 Pa, 1271 μatm) on early development, larval metabolic and feeding rates in a marine model organism, the sea urchin Strongylocentrotus purpuratus. Growth and development was assessed by measuring total body length, body rod length, postoral rod length and posterolateral rod length. Comparing these parameters between treatments suggests that larvae suffer from a developmental delay (by ca. 8%) rather than from the previously postulated reductions in size at comparable developmental stages. Further, we found maximum increases in respiration rates of +100% under elevated pCO(2), while body length corrected feeding rates did not differ between larvae from both treatments. Calculating scope for growth illustrates that larvae raised under high pCO(2) spent an average of 39 to 45% of the available energy for somatic growth, while control larvae could allocate between 78 and 80% of the available energy into growth processes. Our results highlight the importance of defining a standard frame of reference when comparing a given parameter between treatments, as observed differences can be easily due to comparison of different larval ages with their specific set of biological characters.

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

    NASA Technical Reports Server (NTRS)

    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.

  1. Ion channels: Key elements in sea urchin sperm physiology

    NASA Astrophysics Data System (ADS)

    Darszon, Alberto; de De Latorre, Lucia; Vargas, Irma; Liévano, Arturo; Beltrán, Carmen; Santi, Celia; Labarca, Pedro; Zapata, Otilia

    1995-08-01

    Ion channels are deeply involved in sea urchin sperm activation, motility, chemotaxis and in the acrosome reaction. Unraveling ion channel function and regulation in sperm behavior has required a combination of complementary approaches since spermatozoa are very tiny cells. Planar bilayer and patch clamp techniques have allowed us to detect, for the first time, the activity of single channels in the plasma membrane of these cells. Unlike intact sperm, swollen sperm can be much more easily patch clamped and single channel activity recorded. These techniques, together with studies of membrane potential, intracellular Ca2+ and pH in whole sperm, have established the presence of K+, Ca2+, and Cl- channels in this cell. The strategies developed to study sea urchin sperm channels are applicable to mammalian spermatozoa. We recently detected a Ca2+ channel resembling one found in S. purpuratus sperm in planar bilayers containing mouse sperm plasma membranes. The presence of this Ca2+ channel in such diverse species suggests it is important in sperm function.

  2. Characterization of sea urchin unconventional myosins and analysis of their patterns of expression during early embryogenesis.

    PubMed

    Sirotkin, V; Seipel, S; Krendel, M; Bonder, E M

    2000-10-01

    Early sea urchin development requires a dynamic reorganization of both the actin cytoskeleton and cytoskeletal interactions with cellular membranes. These events may involve the activities of multiple members of the superfamily of myosin motor proteins. Using RT-PCR with degenerate myosin primers, we identified 11 myosin mRNAs expressed in unfertilized eggs and coelomocytes of the sea urchin Strongylocentrotus purpuratus. Seven of these sea urchin myosins belonged to myosin classes Igamma, II, V, VI, VII, IX, and amoeboid-type I, and the remaining four may be from novel classes. Sea urchin myosins-V, -VI, -VII, and amoeboid-type-I were either completely or partially cloned and their molecular structures characterized. Sea urchin myosins-V, -VI, -VII, and amoeboid-type-I shared a high degree of sequence identity with their respective family members from vertebrates and they retained their class-specific structure and domain organization. Analysis of expression of myosin-V, -VI, -VII, and amoeboid-type-I mRNAs during development revealed that each myosin mRNA displayed a distinct temporal pattern of expression, suggesting that myosins might be involved in specific events of early embryogenesis. Interestingly, the onset of gastrulation appeared to be a pivotal point in modulation of myosin mRNA expression. The presence of multiple myosin mRNAs in eggs and embryos provides insight into the potential involvement of multiple specific motor proteins in the actin-dependent events of embryo development.

  3. Speract, a sea urchin egg peptide that regulates sperm motility, also stimulates sperm mitochondrial metabolism.

    PubMed

    García-Rincón, Juan; Darszon, Alberto; Beltrán, Carmen

    2016-04-01

    Sea urchin sperm have only one mitochondrion, that in addition to being the main source of energy, may modulate intracellular Ca(2+) concentration ([Ca(2+)]i) to regulate their motility and possibly the acrosome reaction. Speract is a decapeptide from the outer jelly layer of the Strongylocentrotus purpuratus egg that upon binding to its receptor in the sperm, stimulates sperm motility, respiration and ion fluxes, among other physiological events. Altering the sea urchin sperm mitochondrial function with specific inhibitors of this organelle, increases [Ca(2+)]i in an external Ca(2+) concentration ([Ca(2+)]ext)-dependent manner (Ardón, et al., 2009. BBActa 1787: 15), suggesting that the mitochondrion is involved in sperm [Ca(2+)]i homeostasis. To further understand the interrelationship between the mitochondrion and the speract responses, we measured mitochondrial membrane potential (ΔΨ) and NADH levels. We found that the stimulation of sperm with speract depolarizes the mitochondrion and increases the levels of NADH. Surprisingly, these responses are independent of external Ca(2+) and are due to the increase in intracellular pH (pHi) induced by speract. Our findings indicate that speract, by regulating pHi, in addition to [Ca(2+)]i, may finely modulate mitochondrial metabolism to control motility and ensure that sperm reach the egg and fertilize it.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26634300

  5. Lineage and fate of each blastomere of the eight-cell sea urchin embryo.

    PubMed

    Cameron, R A; Hough-Evans, B R; Britten, R J; Davidson, E H

    1987-03-01

    A fluoresceinated lineage tracer was injected into individual blastomeres of eight-cell sea urchin (Strongylocentrotus purpuratus) embryos, and the location of the progeny of each blastomere was determined in the fully developed pluteus. Each blastomere gives rise to a unique portion of the advanced embryo. We confirm many of the classical assignments of cell fate along the animal-vegetal axis of the cleavage-stage embryo, and demonstrate that one blastomere of the animal quartet at the eight-cell stage lies nearest the future oral pole and the opposite one nearest the future aboral pole of the embryo. Clones of cells deriving from ectodermal founder cells always remain contiguous, while clones of cells descendant from the vegetal plate (i.e., gut, secondary mesenchyme) do not. The locations of ectodermal clones contributed by specific blastomeres require that the larval plane of bilateral symmetry lie approximately equidistant (i.e., at a 45 degree angle) from each of the first two cleavage planes. These results underscore the conclusion that many of the early spatial patterns of differential gene expression observed at the molecular level are specified in a clonal manner early in embryonic sea urchin development, and are each confined to cell lineages established during cleavage.

  6. Role of the extracellular matrix in tissue-specific gene expression in the sea urchin embryo.

    PubMed

    Benson, S; Rawson, R; Killian, C; Wilt, F

    1991-07-01

    The role of extracellular matrix (ECM) in the differentiation of tissue types was examined in embryos of Strongylocentrotus purpuratus. We have examined the expression of various tissue-specific molecular markers after disrupting the ECM by culturing embryos in the presence of beta-aminoproprionitrile fumarate (BAPN), which disrupts collagen deposition, and beta-D-xyloside, which disrupts proteoglycan metabolism. The markers examined included accumulation of primary mesenchyme-specific mRNA (SM 50); an aboral ectoderm-specific mRNA (Spec 1); and a gut-specific enzyme, alkaline phosphatase. Treatment with BAPN or beta-D-xyloside results in developmental arrest at the mesenchyme blastula stage. Although spicule formation is inhibited, the accumulation of SM 50 transcripts and the synthesis of most of the prominent spicule matrix proteins is similar to that of control embryos. Spec 1 mRNA, in contrast, while accumulating to a significant extent when collagen and proteoglycan metabolism is disrupted, does accumulate to a level somewhat lower than that seen in control embryos. Additionally, the postgastrula rise in gut-specific alkaline phosphatase is reversibly inhibited by BAPN and xyloside treatment. These results demonstrate a differential effect of the ECM on expression of tissue-specific molecular markers.

  7. Identification of a cell lineage-specific gene coding for a sea urchin alpha 2(IV)-like collagen chain.

    PubMed

    Exposito, J Y; Suzuki, H; Geourjon, C; Garrone, R; Solursh, M; Ramirez, F

    1994-05-06

    We report the isolation of several overlapping cDNAs from an embryonic library of Strongylocentrotus purpuratus coding for a novel sea urchin collagen chain. The conceptual amino acid translation of the cDNAs indicated that the protein displays the structural features of a vertebrate type IV-like collagen alpha chain. In addition to a putative 31-residue signal peptide, the sea urchin molecule contains a 14-residue amino-terminal non-collagenous segment, a discontinuous 1,477-amino acid triple helical domain, and a 225-residue carboxyl-terminal domain rich in cysteines. The amino- and carboxyl-terminal non-collagenous regions of the echinoid molecule are remarkably similar to the 7 S and carboxyl-terminal non-collagenous (NC1) domains of the alpha 1 and alpha 2 chains of vertebrate type IV collagen. The sequence similarity and distinct structural features of the 7 S and NC1 domains strongly suggest that the sea urchin polypeptide is evolutionarily related to the alpha 2(IV) class of collagen chains. Finally, in situ hybridizations revealed that expression of this collagen gene is restricted to the mesenchyme cell lineage of the developing sea urchin embryo.

  8. Reproduction on the edge: large-scale patterns of individual performance in a marine invertebrate.

    PubMed

    Lester, Sarah E; Gaines, Steven D; Kinlan, Brian P

    2007-09-01

    Reproductive output is a central attribute of life history, providing a measure of individual and population performance. The fields of ecology, biogeography, and evolutionary biology take disparate approaches in addressing spatial variation in reproduction, and thus we lack clear predictions for how reproductive output should vary geographically. We empirically investigate these contrasting theoretical approaches by determining geographic patterns in reproductive output for intertidal populations of the purple sea urchin, Strongylocentrotus purpuratus, at 15 sites spanning a large geographic distance (9 degrees span of latitude) from central California, USA, to Baja California, Mexico. Contrary to predictions from biogeography, some of the highest values of reproductive output are at sites near the species' southern range boundary. Additionally, sea urchins do not exhibit a latitudinal gradient in reproduction, but rather show considerable mesoscale variation in reproductive output. Spatial analyses reveal that this variation is correlated with coastal topographic features that are known to influence the pattern of nearshore nutrient flux and circulation. We hypothesize that urchins' reproductive output may be driven by the spatial distribution of their food supply, drift macroalgae, the abundance of which is influenced by both nutrient supply and alongshore transport processes that are coupled to topographic features. Large-scale studies such as this provide valuable insight into the causes of species' range limits, population connectivity, habitat reserve design, and forecasting the effects of climate change on species' distributions.

  9. An evolutionary transition of Vasa regulation in echinoderms.

    PubMed

    Juliano, Celina E; Wessel, Gary M

    2009-01-01

    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.

  10. Neuropeptides and polypeptide hormones in echinoderms: new insights from analysis of the transcriptome of the sea cucumber Apostichopus japonicus.

    PubMed

    Rowe, Matthew L; Achhala, Sufyan; Elphick, Maurice R

    2014-02-01

    Echinoderms are of special interest for studies in comparative endocrinology because of their phylogenetic position in the animal kingdom as deuterostomian invertebrates. Furthermore, their pentaradial symmetry as adult animals provides a unique context for analysis of the physiological and behavioral roles of peptide signaling systems. Here we report the first extensive survey of neuropeptide and peptide hormone precursors in a species belonging to the class Holothuroidea. Transcriptome sequence data obtained from the sea cucumber Apostichopus japonicus were analyzed to identify homologs of precursor proteins that have recently been identified in the sea urchin Strongylocentrotus purpuratus (class Echinoidea). A total of 17 precursor proteins have been identified in A. japonicus, including precursors of peptides related to thyrotropin-releasing hormone, pedal peptide/orcokinin-type peptides, AN peptides/tachykinins, luqins, corticotropin-releasing hormone (CRH), GPA2-type glycoprotein hormone subunits and bursicon. In addition, an unusual finding was an A. japonicus calcitonin-type precursor protein (AjCTLPP), the first to be discovered that comprises two calcitonin-like peptides; this contrasts with the products of the alternatively-spliced calcitonin/CGRP gene in vertebrates, which comprise either calcitonin or CGRP. Collectively, the data obtained provide new insights on the evolution and diversity of neuropeptides and polypeptide hormones. Furthermore, because A. japonicus is one of several sea cucumber species that are used for human consumption, our findings may have practical and economic impact by providing a basis for neuroendocrine-based strategies to improve methods of aquaculture.

  11. Validating the Assumption of Annual Shell Ring Deposition in Freshwater Mussels

    NASA Astrophysics Data System (ADS)

    Commens, A. M.; Haag, W. R.

    2005-05-01

    We evaluated the assumption of annual shell ring deposition by freshwater mussels in three rivers (Little Tallahatchie, Mississippi, 2000 and 2003; Sipsey, Alabama, 2000; St. Frances, Arkansas, 2003) using 14 species (Amblema plicata, Elliptio arca, Fusconaia cerina, F. flava, Lampsilis cardium, L. teres, Leptodea fragilis, Obliquaria reflexa, Potamilus purpuratus, Quadrula asperata, Q. pustulosa, Q. quadrula, Q, rumphiana, Tritogonia verrucosa). In 2000 we filed a notch in the shell margin, returned animals to the water, and retrieved them one year later. In 2003 we measured shell length and affixed numbered tags, returned animals to the water, and retrieved them one year later. After retrieval, we examined external and internal shell rings using thin-sections. For both methods, all species at all sites grew and deposited a single winter rest line between times of initial and final collection. Handling produced a conspicuous disturbance ring in all species. Characteristics of annual rings, disturbance rings, and false annuli differed qualitatively. Growth of some individuals was reduced after handling but negative growth occurred only in a few large individuals. Annual shell ring formation occurs consistently across species, space, and time. Formation of disturbance rings associated with collection indicates that mussels are extremely sensitive to handling.

  12. Transient translational quiescence in primordial germ cells.

    PubMed

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

    2017-02-24

    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. Knock-down of translation of the RNA-binding protein Nanos2 by morpholino anti-sense oligonucleotides, or knock-out 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.

  13. Embryotoxicity of TiO2 nanoparticles to Mytilus galloprovincialis (Lmk).

    PubMed

    Libralato, Giovanni; Minetto, Diego; Totaro, Sara; Mičetić, Ivan; Pigozzo, Andrea; Sabbioni, Enrico; Marcomini, Antonio; Volpi Ghirardini, Annamaria

    2013-12-01

    Few data exist on the ecotoxicological effects of nanosized titanium dioxide (nTiO2) towards marine species with specific reference to bivalve molluscs and their relative life stages. Mytilus galloprovincialis Lamarck was selected to assess the potential adverse effects of nTiO2 (0-64 mg/L) on its early larval development stages (pre-D shell stage, malformed D-shell stage and normal D-shell stage larvae) considering two exposure scenarios characterised by total darkness (ASTM protocol) and natural photoperiod (light/dark). This approach was considered to check the presence of potential effects associated to the photocatalytic properties of nTiO2. Parallel experiments were carried on with the bulk reference TiCl4. The toxicity of nTiO2 showed to be mainly related to its "nano" condition and to be influenced by the exposure to light that supported the increase in the number of pre-D shell stage (retarded) larvae compared to the malformed ones especially at the maximum effect concentrations (4 and 8 mg nTiO2/L). The non-linear regression toxicity data analysis showed the presence of two EC50 values per exposure scenario: a) EC(50)1 = 1.23 mg/L (0.00-4.15 mg/L) and EC(50)2 = 38.56 mg/L (35.64-41.47 mg/L) for the dark exposure conditions; b) EC(50)1 = 1.65 mg/L (0.00-4.74 mg/L) and EC(50)2 = 16.39 mg/L (13.31-19.48 mg/L) for the light/dark exposure conditions. The potential implication of agglomeration and sedimentation phenomena on ecotoxicological data was discussed.

  14. Distinguishing suitable biotypes of Dactylopius tomentosus (Hemiptera: Dactylopiidae) for biological control of Cylindropuntia fulgida var. fulgida (Caryophyllales: Cactaceae) in South Africa.

    PubMed

    Mathenge, C W; Holford, P; Hoffmann, J H; Zimmermann, H G; Spooner-Hart, R; Beattie, G A C

    2009-12-01

    Cylindropuntia fulgida (Engelmann) F.M. Knuth var. fulgida (Engelmann) F.M. Knuth (Cff) (Caryophyllales: Cactaceae) is native to Mexico and Arizona and was introduced into South Africa for ornamental purposes. It subsequently became highly invasive, necessitating control. The cochineal insect, Dactylopius tomentosus (Lamarck) (Hemiptera: Dactylopiidae), was selected as a potential biological control agent based on its restricted host range among Cylindropuntia species and previous success in controlling C. imbricata (DC.) F. Knuth (Ci). Eight D. tomentosus provenances (Cholla, Cholla E, Fulgida, Mamillata, Imbricata, Tunicata U, Tunicata V and Rosea) from Cylindropuntia species in their native ranges were reared on Cff, whilst Cholla and Imbricata were also reared on Ci. Large differences were found in the development and survival of crawlers, and in the reproductive capacity of females. Three subjective categories of provenance interaction with host plants were identified based on a fitness index (FI) calculated from data relating to crawler survival, female development time and fecundity: (i) thriving (FI > or = 1) - insects had shorter developmental times, high crawler survival and highly fecund females (Cholla); (ii) surviving (FI<1 but >0) - insects had extended development times, low crawler survival and low fecundity (Imbricata, Fulgida and Mamillata); and (iii) dying (FI = 0) - insects died before or at the second instar (Rosea, Tunicata U and Tunicata V). Cholla, therefore, is highly suitable for biological control of Cff in South Africa. In addition, Cholla thrived on Cff but only survived on Ci whilst, in contrast, Imbricata thrived on Ci but only survived on Cff. This differential ability of provenances to thrive or survive on different host plants demonstrated that host adapted biotypes of D. tomentosus exist; therefore, biotypes should be taken into account when considering this species as a biological control agent of cactus weeds.

  15. A biomonitoring study: trace metals in algae and molluscs from Tyrrhenian coastal areas.

    PubMed

    Conti, Marcelo Enrique; Cecchetti, Gaetano

    2003-09-01

    Marine organisms were evaluated as possible biomonitors of heavy metal contamination in marine coastal areas. Concentrations of Cd, Cr, Cu, Pb, and Zn were measured in the green algae Ulva lactuca L., the brown algae Padina pavonica (L.) Thivy, the bivalve mollusc Mytilus galloprovincialis Lamarck, and the two gastropod molluscs Monodonta turbinata Born and Patella cerulea L. collected at six coastal stations in the area of the Gulf of Gaeta (Tyrrhenian Sea, central Italy). The coastal area of the Regional Park of Gianola and Monte di Scauri (a "Protected Sea Park" area) was chosen as a control site. Seawater samples were also collected in each site to assess soluble and total metal concentrations and to gain additional information on both the environmental conditions of the area and possible bioaccumulation patterns. Metal concentrations detected in algae and molluscs did not show significant differences among all stations studied. Moreover, statistical analyses (ANOVA, multiple comparison tests, cluster analysis) showed that the Sea Park station was not significantly different from the others. The hypothesis that the Protected Sea Park would be cleaner than the others must therefore be reconsidered. Data from this study were also compared with those previously obtained from uncontaminated sites in the Sicilian Sea, Italy. The results show clearly differences between these two marine ecosystems. The species examined showed great accumulations of metals, with concentration factors (CFs) higher than 10,000 with respect to the concentrations (soluble fractions) in marine waters. Metal concentrations recorded in this area may be used for background levels for intraspecific comparison within the Tyrrhenian area, a body of water about which information is still very scarce.

  16. On Darwin's 'metaphysical notebooks'. I: teleology and the project of a theory.

    PubMed

    Calabi, L

    2001-01-01

    Huxley's essay On the Reception of the 'Origin of Species' brings us close to the issue of cause and of why- and how-questions in the understanding of the living world. The present contribution, which is divided into two parts, reviews the problem of Teleology as conceived by Huxley and re-examines Darwin as the author who revealed the existence of a 'foundations problem' in the explanation of an entire realm of nature, i.e., the problem of explaining such realm in terms of its own, specific legality, or iuxta sua propria principia. In the first part the enquiry is mainly focused on the secularization of natural history after Paley; in the second part it is mainly focused on the desubjectivization of the inquiry into natural history after Erasmus Darwin and Lamarck. The second part will be published in the next issue of Rivista di Biologia/Biology Forum. In the first part below an analysis is made of Notebooks M and N. The author disputes the correctness of conceiving them only as the works where Darwin envisages the 'metaphysical' themes later to become the subject of The Expression of the Emotions. He suggests to conceive of them also as the works where Darwin defines the terms of the general project of his own, peculiar evolutionary theory. The author then outlines the intellectual progress of Darwin from the inosculation to the transmutation hypotheses. Darwin's reading of Malthus appears to be analytically decisive, because it offers him the vintage point to attack the metaphysical and theological citadels on the morphological side. Darwin is thus able to re-consider Erasmus' comprehensive zoonomic project, by displacing it, however, from the old idea of the scala naturae to the new one of the "coral of life", and by emphasising the distinction between "the fittest" and "the best" vs. the tradition of Natural Theology.

  17. High-quality RNA extraction from the sea urchin Paracentrotus lividus embryos.

    PubMed

    Ruocco, Nadia; Costantini, Susan; Zupo, Valerio; Romano, Giovanna; Ianora, Adrianna; Fontana, Angelo; Costantini, Maria

    2017-01-01

    The sea urchin Paracentrotus lividus (Lamarck, 1816) is a keystone herbivore in the Mediterranean Sea due to its ability to transform macroalgal-dominated communities into barren areas characterized by increased cover of bare substrates and encrusting coralline algae, reduced biodiversity and altered ecosystem functions. P. lividus is also an excellent animal model for toxicology, physiology and biology investigations having been used for more than a century as a model for embryological studies with synchronously developing embryos which are easy to manipulate and analyze for morphological aberrations. Despite its importance for the scientific community, the complete genome is still not fully annotated. To date, only a few molecular tools are available and a few Next Generation Sequencing (NGS) studies have been performed. Here we aimed at setting-up an RNA extraction method to obtain high quality and sufficient quantity of RNA for NGS from P. lividus embryos at the pluteus stage. We compared five different RNA extraction protocols from four different pools of plutei (500, 1000, 2500 and 5000 embryos): TRIzol®, and four widely-used Silica Membrane kits, GenElute™ Mammalian Total RNA Miniprep Kit, RNAqueous® Micro Kit, RNeasy® Micro Kit and Aurum™ Total RNA Mini Kit. The quantity of RNA isolated was evaluated using NanoDrop. The quality, considering the purity, was measured as A260/A280 and A260/230 ratios. The integrity was measured by RNA Integrity Number (RIN). Our results demonstrated that the most efficient procedures were GenElute, RNeasy and Aurum, producing a sufficient quantity of RNA for NGS. The Bioanalyzer profiles and RIN values revealed that the most efficient methods guaranteeing for RNA integrity were RNeasy and Aurum combined with an initial preservation in RNAlater. This research represents the first attempt to standardize a method for high-quality RNA extraction from sea urchin embryos at the pluteus stage, providing a new resource for this

  18. The mitochondrial genomes of sponges provide evidence for multiple invasions by Repetitive Hairpin-forming Elements (RHE)

    PubMed Central

    2009-01-01

    Background The mitochondrial (mt) genomes of sponges possess a variety of features, which appear to be intermediate between those of Eumetazoa and non-metazoan opisthokonts. Among these features is the presence of long intergenic regions, which are common in other eukaryotes, but generally absent in Eumetazoa. Here we analyse poriferan mitochondrial intergenic regions, paying particular attention to repetitive sequences within them. In this context we introduce the mitochondrial genome of Ircinia strobilina (Lamarck, 1816; Demospongiae: Dictyoceratida) and compare it with mtDNA of other sponges. Results Mt genomes of dictyoceratid sponges are identical in gene order and content but display major differences in size and organization of intergenic regions. An even higher degree of diversity in the structure of intergenic regions was found among different orders of demosponges. One interesting observation made from such comparisons was of what appears to be recurrent invasions of sponge mitochondrial genomes by repetitive hairpin-forming elements, which cause large genome size differences even among closely related taxa. These repetitive hairpin-forming elements are structurally and compositionally divergent and display a scattered distribution throughout various groups of demosponges. Conclusion Large intergenic regions of poriferan mt genomes are targets for insertions of repetitive hairpin- forming elements, similar to the ones found in non-metazoan opisthokonts. Such elements were likely present in some lineages early in animal mitochondrial genome evolution but were subsequently lost during the reduction of intergenic regions, which occurred in the Eumetazoa lineage after the split of Porifera. Porifera acquired their elements in several independent events. Patterns of their intra-genomic dispersal can be seen in the mt genome of Vaceletia sp. PMID:20003196

  19. The Oxford Companion to the Earth

    NASA Astrophysics Data System (ADS)

    Hancock, Paul L.

    2001-06-01

    Here is a wealth of information on planet Earth, ranging from the heights of the ionsphere down to the red-hot molten core. Written by some 200 expert contributors, and illustrated with over 600 pictures, including 16 pages of color plates, The Oxford Companion to the Earth offers 900 alphabetically arranged entries that cover everything from deserts and wetlands to mountains, caves, glaciers, and coral reefs. There are articles on natural phenomena such as tornadoes and tsunamis, volcanoes and earthquakes, jet streams and weather fronts; on the history of Earth, including the origin of life, Burgess Shale fauna, dinosaurs, and the Ice Ages; on key figures, such as Agassiz, Cuvier, Darwin, and Lamarck; and on such important ecological concerns as acid rain, the ozone layer, industrial waste disposal, and the greenhouse effect. The Companion also examines the great sources of wealth to be found in the Earth, from coal and oil to gold, silver, and diamonds, and many curious land formations, from sinkholes and fiords to yardangs and quicksand. There are brief entries on rock types, from amber to travertine, and extensive essays on cutting-edge aspects of the earth sciences, such as seismology and marine geology. The Companion includes extensive cross-references, suggested further reading, an index, and many useful appendices, with a geological timescale, facts and figures about the Earth, and a table of chemical elements. The Oxford Companion to the Earth is a unique reference work, offering unrivaled coverage of our home planet. Generously illustrated and vividly written, it is a treasure house of information for all lovers of natural history, geology, and ecology, whether professional or amateur.

  20. Temporal dynamics of arthropods on six tree species in dry woodlands on the Caribbean Island of Puerto Rico.

    PubMed

    Beltrán, William; Wunderle, Joseph M

    2014-01-01

    The seasonal dynamics of foliage arthropod populations are poorly studied in tropical dry forests despite the importance of these studies for understanding arthropod population responses to environmental change. We monitored the abundance, temporal distributions, and body size of arthropods in five naturalized alien and one native tree species to characterize arthropod seasonality in dry novel Prosopis-Leucaena woodlands in Puerto Rico. A branch clipping method was used monthly to sample foliage arthropod abundance over 39 mo. Seasonal patterns of rainfall and abundance within various arthropod taxa were highly variable from year to year. Abundance for most taxa did not show significant seasonality over the 3 yr, although most taxa had abundance peaks each year. However, Homoptera displayed high seasonality with significant temporal aggregations in each year. Formicidae, Orthoptera, and Coleoptera showed high variation in abundance between wet and dry periods, whereas Hemiptera were consistently more abundant in the wet period. Seasonal differences in mean abundance were found only in a few taxa on Tamarindus indica L., Bucida buceras L., Pithecellobium dulce, and (Roxburgh) Benth. Mean arthropod abundance varied among tree species, with highest numbers on Prosopis juliflora, (Swartz) De Candolle, Pi. dulce, Leucaena leucocephala, and (Lamarck) de Wit. Abundance of Araneae, Orthoptera, Coleoptera, Lepidoptera larvae, and all arthropods showed weak relationships with one or more climatic variables (rainfall, maximum temperature, or relative humidity). Body size of arthropods was usually largest during the dry periods. Overall, total foliage arthropod abundance showed no consistent seasonality among years, which may become a more common trend in dry forests and woodlands in the Caribbean if seasonality of rainfall becomes less predictable.

  1. Stable Isotope Evidence for Dietary Overlap between Alien and Native Gastropods in Coastal Lakes of Northern KwaZulu-Natal, South Africa

    PubMed Central

    Miranda, Nelson A. F.; Perissinotto, Renzo

    2012-01-01

    Background Tarebia granifera (Lamarck, 1822) is originally from South-East Asia, but has been introduced and become invasive in many tropical and subtropical parts of the world. In South Africa, T. granifera is rapidly invading an increasing number of coastal lakes and estuaries, often reaching very high population densities and dominating shallow water benthic invertebrate assemblages. An assessment of the feeding dynamics of T. granifera has raised questions about potential ecological impacts, specifically in terms of its dietary overlap with native gastropods. Methodology/Principal Findings A stable isotope mixing model was used together with gut content analysis to estimate the diet of T. granifera and native gastropod populations in three different coastal lakes. Population density, available biomass of food and salinity were measured along transects placed over T. granifera patches. An index of isotopic (stable isotopes) dietary overlap (IDO, %) aided in interpreting interactions between gastropods. The diet of T. granifera was variable, including contributions from microphytobenthos, filamentous algae (Cladophora sp.), detritus and sedimentary organic matter. IDO was significant (>60%) between T. granifera and each of the following gastropods: Haminoea natalensis (Krauss, 1848), Bulinus natalensis (Küster, 1841) and Melanoides tuberculata (Müller, 1774). However, food did not appear to be limiting. Salinity influenced gastropod spatial overlap. Tarebia granifera may only displace native gastropods, such as Assiminea cf. ovata (Krauss, 1848), under salinity conditions below 20. Ecosystem-level impacts are also discussed. Conclusion/Significance The generalist diet of T. granifera may certainly contribute to its successful establishment. However, although competition for resources may take place under certain salinity conditions and if food is limiting, there appear to be other mechanisms at work, through which T. granifera displaces native gastropods

  2. Consumption rates and prey preference of the invasive gastropod Rapana venosa in the Northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Savini, Dario; Occhipinti-Ambrogi, Anna

    2006-05-01

    The alien Asian gastropod Rapana venosa (Valenciennes 1846) was first recorded in 1973 along the Italian coast of the Northern Adriatic Sea. Recently, this predator of bivalves has been spreading all around the world oceans, probably helped by ship traffic and aquaculture trade. A caging experiment in natural environment was performed during the summer of 2002 in Cesenatico (Emilia-Romagna, Italy) in order to estimate consumption rates and prey preference of R. venosa. The prey items chosen were the Mediterranean mussel Mytilus galloprovincialis (Lamarck 1819), the introduced carpet clam Tapes philippinarum (Adams and Reeve 1850), both supporting the local fisheries, and the Indo-Pacific invasive clam Anadara (Scapharca) inaequivalvis (Bruguière 1789). Results showed an average consumption of about 1 bivalve prey per day (or 1.2 g wet weight per day). Predation was species and size selective towards small specimens of A. inaequivalvis; consumption of the two commercial species was lower. These results might reduce the concern about the economical impact on the local bivalve fishery due to the presence of the predatory gastropod. On the other hand, selective predation might probably alter local community structure, influencing competition amongst filter feeder/suspension feeder bivalve species and causing long-term ecological impact. The large availability of food resource and the habitat characteristics of the Emilia-Romagna littoral makes this area an important breeding ground for R. venosa in the Mediterranean Sea, thus worthy of consideration in order to understand the bioinvasion ecology of this species and to control its likely further dispersal.

  3. Amphimixis and the individual in evolving populations: does Weismann's Doctrine apply to all, most or a few organisms?

    NASA Astrophysics Data System (ADS)

    Niklas, Karl J.; Kutschera, Ulrich

    2014-05-01

    The German biologist August Weismann (1834-1914) proposed that amphimixis (sexual reproduction) creates variability for natural selection to act upon, and hence he became one of the founders of the Neo-Darwinian theory of biological evolution. He is perhaps best known for what is called "Weismann's Doctrine" or "Weismann's Barrier" (i.e. the irreversible separation of somatic and germ cell functionalities early during ontogeny in multicellular organisms). This concept provided an unassailable argument against "soft inheritance" sensu Lamarck and informed subsequent theorists that the only "individual" in the context of evolution is the mature, reproductive organism. Herein, we review representative model organisms whose embryology conforms to Weismann's Doctrine (e.g. flies and mammals) and those that do not (e.g. freshwater hydroids and plants) based on this survey and the Five Kingdoms of Life scheme; we point out that most species (notably bacteria, fungi, protists and plants) are "non-Weismannian" in ways that make a canonical definition of the "individual" problematic if not impossible. We also review critical life history functional traits that allow us to create a matrix of all theoretically conceivable life cycles (for eukaryotic algae, embryophytes, fungi and animals), which permits us to establish where this scheme Weismann's Doctrine holds true and where it does not. In addition, we argue that bacteria, the dominant organisms of the biosphere, exist in super-cellular biofilms but rarely as single (planktonic) microbes. Our analysis attempts to show that competition among genomic variants in cell lineages played a critical part in the evolution of multicellularity and life cycle diversity. This feature was largely ignored during the formulation of the synthetic theory of biological evolution and its subsequent elaborations.

  4. High-quality RNA extraction from the sea urchin Paracentrotus lividus embryos

    PubMed Central

    Ruocco, Nadia; Costantini, Susan; Zupo, Valerio; Romano, Giovanna; Ianora, Adrianna; Fontana, Angelo; Costantini, Maria

    2017-01-01

    The sea urchin Paracentrotus lividus (Lamarck, 1816) is a keystone herbivore in the Mediterranean Sea due to its ability to transform macroalgal-dominated communities into barren areas characterized by increased cover of bare substrates and encrusting coralline algae, reduced biodiversity and altered ecosystem functions. P. lividus is also an excellent animal model for toxicology, physiology and biology investigations having been used for more than a century as a model for embryological studies with synchronously developing embryos which are easy to manipulate and analyze for morphological aberrations. Despite its importance for the scientific community, the complete genome is still not fully annotated. To date, only a few molecular tools are available and a few Next Generation Sequencing (NGS) studies have been performed. Here we aimed at setting-up an RNA extraction method to obtain high quality and sufficient quantity of RNA for NGS from P. lividus embryos at the pluteus stage. We compared five different RNA extraction protocols from four different pools of plutei (500, 1000, 2500 and 5000 embryos): TRIzol®, and four widely-used Silica Membrane kits, GenElute™ Mammalian Total RNA Miniprep Kit, RNAqueous® Micro Kit, RNeasy® Micro Kit and Aurum™ Total RNA Mini Kit. The quantity of RNA isolated was evaluated using NanoDrop. The quality, considering the purity, was measured as A260/A280 and A260/230 ratios. The integrity was measured by RNA Integrity Number (RIN). Our results demonstrated that the most efficient procedures were GenElute, RNeasy and Aurum, producing a sufficient quantity of RNA for NGS. The Bioanalyzer profiles and RIN values revealed that the most efficient methods guaranteeing for RNA integrity were RNeasy and Aurum combined with an initial preservation in RNAlater. This research represents the first attempt to standardize a method for high-quality RNA extraction from sea urchin embryos at the pluteus stage, providing a new resource for this

  5. Darwin's passionate environmentalism or the dangerous fallacy of the 'All-sufficiency of natural selection' theory.

    PubMed

    Marsh, David

    2012-01-01

    Following his last edition of the Origin of Species in 1872, Darwin spent much of the rest of his life searching for possible mechanisms, such as the pangenes in the blood, which would communicate information from the environment to the genome. In each of his six editions of the 'Origin', he stated that there were two forces in evolution - natural selection and conditions of existence. Of the two, he claims that the latter is the more powerful. In so doing, he recognized that natural selection could only operate within the bounds of possibility, that is the environment. August Weismann claimed that conditions of existence had no place in evolution. His publication, the 'All-sufficiency of natural selection', was based on mutilation (cutting tails of rodents and watching the next generation grow tails), which has nothing to do with Darwin's concept of conditions of existence. Nonetheless, evolutionary biologists in general followed the line of the 'all sufficiency' theory and ignored Darwin's conditions of existence, which in other words means the environment. Natural selection has a weak predictive power as it is based on random events. However, the conditions of existence have, by contrast, strong predictive powers that can be tested. The environmental views of two of the greatest evolutionists, Lamarck and Darwin, have been consistently ignored by most evolution theorists who came after them, continuing for over 200 years. Looking at the fossil record through the eyes of Darwin's conditions of existence, not to mention the recent changes in height and shape over the last century, it is possible to draw important conclusions about the past and predictions of the future. With new knowledge of epigenetics, it is perhaps time that Darwin's conditions of existence were given a second hearing.

  6. Benefit of pulsation in soft corals.

    PubMed

    Kremien, Maya; Shavit, Uri; Mass, Tali; Genin, Amatzia

    2013-05-28

    Soft corals of the family Xeniidae exhibit a unique, rhythmic pulsation of their tentacles (Movie S1), first noted by Lamarck nearly 200 y ago. However, the adaptive benefit of this perpetual, energetically costly motion is poorly understood. Using in situ underwater particle image velocimetry, we found that the pulsation motions thrust water upward and enhance mixing across the coral-water boundary layer. The induced upward motion effectively prevents refiltration of water by neighboring polyps, while the intensification of mixing, together with the upward flow, greatly enhances the coral's photosynthesis. A series of controlled laboratory experiments with the common xeniid coral Heteroxenia fuscescens showed that the net photosynthesis rate during pulsation was up to an order of magnitude higher than during the coral's resting, nonpulsating state. This enhancement diminished when the concentration of oxygen in the ambient water was artificially raised, indicating that the enhancement of photosynthesis was due to a greater efflux of oxygen from the coral tissues. By lowering the internal oxygen concentration, pulsation alleviates the problem of reduced affinity of ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO) to CO2 under conditions of high oxygen concentrations. The photosynthesis-respiration ratio of the pulsating H. fuscescens was markedly higher than the ratios reported for nonpulsating soft and stony corals. Although pulsation is commonly used for locomotion and filtration in marine mobile animals, its occurrence in sessile (bottom-attached) species is limited to members of the ancient phylum Cnidaria, where it is used to accelerate water and enhance physiological processes.

  7. Temporal Dynamics of Arthropods on Six Tree Species in Dry Woodlands on the Caribbean Island of Puerto Rico

    PubMed Central

    Beltrán, William; Wunderle, Joseph M.

    2014-01-01

    The seasonal dynamics of foliage arthropod populations are poorly studied in tropical dry forests despite the importance of these studies for understanding arthropod population responses to environmental change. We monitored the abundance, temporal distributions, and body size of arthropods in five naturalized alien and one native tree species to characterize arthropod seasonality in dry novel Prosopis–Leucaena woodlands in Puerto Rico. A branch clipping method was used monthly to sample foliage arthropod abundance over 39 mo. Seasonal patterns of rainfall and abundance within various arthropod taxa were highly variable from year to year. Abundance for most taxa did not show significant seasonality over the 3 yr, although most taxa had abundance peaks each year. However, Homoptera displayed high seasonality with significant temporal aggregations in each year. Formicidae, Orthoptera, and Coleoptera showed high variation in abundance between wet and dry periods, whereas Hemiptera were consistently more abundant in the wet period. Seasonal differences in mean abundance were found only in a few taxa on Tamarindus indica L., Bucida buceras L., Pithecellobium dulce, and (Roxburgh) Benth. Mean arthropod abundance varied among tree species, with highest numbers on Prosopis juliflora, (Swartz) De Candolle, Pi. dulce, Leucaena leucocephala, and (Lamarck) de Wit. Abundance of Araneae, Orthoptera, Coleoptera, Lepidoptera larvae, and all arthropods showed weak relationships with one or more climatic variables (rainfall, maximum temperature, or relative humidity). Body size of arthropods was usually largest during the dry periods. Overall, total foliage arthropod abundance showed no consistent seasonality among years, which may become a more common trend in dry forests and woodlands in the Caribbean if seasonality of rainfall becomes less predictable. PMID:25502036

  8. Inhibition of lipopolysaccharide-induced cyclooxygenase-2 and inducible nitric oxide synthase expression by 4-[(2'-O-acetyl-α-L-rhamnosyloxy)benzyl]isothiocyanate from Moringa oleifera.

    PubMed

    Park, Eun-Jung; Cheenpracha, Sarot; Chang, Leng Chee; Kondratyuk, Tamara P; Pezzuto, John M

    2011-01-01

    Moringa oleifera Lamarck is commonly consumed for nutritional or medicinal properties. We recently reported the isolation and structure elucidation of novel bioactive phenolic glycosides, including 4-[(2'-O-acetyl-α-L-rhamnosyloxy)benzyl]isothiocyanate (RBITC), which was found to suppress inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production in lipopolysaccharide-stimulated RAW 264.7 mouse macrophage cells. Inhibitors of proteins such as cyclooxygenase-2 (COX-2) and iNOS are potential antiinflammatory and cancer chemopreventive agents. The inhibitory activity of RBITC on NO production (IC(50) = 0.96 ± 0.23 μM) was greater than that mediated by other well-known isothiocyanates such as sulforaphane (IC(50) = 2.86 ± 0.39 μM) and benzyl isothiocyanate (IC(50) = 2.08 ± 0.28 μM). RBITC inhibited expression of COX-2 and iNOS at both the protein and mRNA levels. Major upstream signaling pathways involved mitogen-activated protein kinases and nuclear factor-κB (NF-κB). RBITC inhibited phosphorylation of extracellular signal-regulated kinase and stress-activated protein kinase, as well as ubiquitin-dependent degradation of inhibitor κBα (IκBα). In accordance with IκBα degradation, nuclear accumulation of NF-κB and subsequent binding to NF-κB cis-acting element was attenuated by treatment with RBITC. These data suggest RBITC should be included in the dietary armamentarium of isothiocyanates potentially capable of mediating antiinflammatory or cancer chemopreventive activity.

  9. Toward an evolutionary-predictive foundation for creativity : Commentary on "Human creativity, evolutionary algorithms, and predictive representations: The mechanics of thought trials" by Arne Dietrich and Hilde Haider, 2014 (Accepted pending minor revisions for publication in Psychonomic Bulletin & Review).

    PubMed

    Gabora, Liane; Kauffman, Stuart

    2016-04-01

    Dietrich and Haider (Psychonomic Bulletin & Review, 21 (5), 897-915, 2014) justify their integrative framework for creativity founded on evolutionary theory and prediction research on the grounds that "theories and approaches guiding empirical research on creativity have not been supported by the neuroimaging evidence." Although this justification is controversial, the general direction holds promise. This commentary clarifies points of disagreement and unresolved issues, and addresses mis-applications of evolutionary theory that lead the authors to adopt a Darwinian (versus Lamarckian) approach. To say that creativity is Darwinian is not to say that it consists of variation plus selection - in the everyday sense of the term - as the authors imply; it is to say that evolution is occurring because selection is affecting the distribution of randomly generated heritable variation across generations. In creative thought the distribution of variants is not key, i.e., one is not inclined toward idea A because 60 % of one's candidate ideas are variants of A while only 40 % are variants of B; one is inclined toward whichever seems best. The authors concede that creative variation is partly directed; however, the greater the extent to which variants are generated non-randomly, the greater the extent to which the distribution of variants can reflect not selection but the initial generation bias. Since each thought in a creative process can alter the selective criteria against which the next is evaluated, there is no demarcation into generations as assumed in a Darwinian model. We address the authors' claim that reduced variability and individuality are more characteristic of Lamarckism than Darwinian evolution, and note that a Lamarckian approach to creativity has addressed the challenge of modeling the emergent features associated with insight.

  10. An annotated catalogue and bibliography of the taxonomy, synonymy and distribution of the Recent Vetigastropoda of South Africa (Mollusca).

    PubMed

    Herbert, David G

    2015-11-30

    A complete inventory of the known Recent vetigastropod fauna of South Africa is provided. Bibliographic citations to works discussing the taxonomy, synonymy and distribution of the species in a southern African or south-western Indian Ocean context are provided. Additional explanatory notes are given where pertinent. New genus records for South Africa: Acremodontina B.A. Marshall, 1995; Choristella Bush, 1879; Cocculinella Thiele, 1909; Conjectura Finlay, 1926; Crosseola Iredale, 1924; Falsimargarita Powell, 1951; Lepetella Verrill, 1880; Profundisepta McLean & Geiger, 1998; Stomatella Lamarck, 1816; Stomatia Helbling, 1779; Stomatolina Iredale, 1937; Synaptocochlea Pilsbry, 1890; Tibatrochus Nomura, 1940; Visayaseguenzia Poppe, Tagaro & Dekker, 2006; Zetela Finlay, 1926. New species records for South Africa: Acremodontina aff. carinata Powell, 1940; Anatoma finlayi (Powell, 1937); Anatoma munieri (P. Fischer, 1862); Calliotropis acherontis B.A. Marshall, 1979; Calliotropis bucina Vilvens, 2006; Cocculinella minutissima (E.A. Smith, 1904); Diodora ruppellii (G.B. Sowerby (I), 1835); Emarginula costulata Deshayes, 1863; Emarginula decorata Deshayes, 1863; Jujubinus hubrechti Poppe, Tagaro & Dekker, 2006; Lepetella sp.; Seguenzia orientalis Thiele, 1925; Stomatella auricula Lamarck, 1816; Stomatia phymotis Helbling, 1779; Stomatolina angulata (A. Adams, 1850); Stomatolina cf. calliostoma (A. Adams, 1850); Stomatolina aff. danblumi Singer & Mienis, 1999; Stomatolina cf. rubra (Lamarck, 1822); Stomatolina sp.; Synaptocochlea concinna (Gould, 1845); Tectus mauritianus (Gmelin, 1791); Tibatrochus cf. incertus (Schepman, 1908); Turbo imperialis Gmelin, 1791; Turbo tursicus Reeve, 1848; Visayaseguenzia compsa (Melvill, 1904).New species: Spectamen martensi, replacement name for Spectamen semisculptum sensu Herbert (1987) (non Martens, 1904). New name: Oxystele antoni is proposed as a new name for Trochus (Turbo) variegatus (non Gmelin, 1791 =Heliacus) Anton, 1838. Revised

  11. Discrete Dynamics Model for the Speract-Activated Ca2+ Signaling Network Relevant to Sperm Motility

    PubMed Central

    Espinal, Jesús; Aldana, Maximino; Guerrero, Adán; Wood, Christopher

    2011-01-01

    Understanding how spermatozoa approach the egg is a central biological issue. Recently a considerable amount of experimental evidence has accumulated on the relation between oscillations in intracellular calcium ion concentration ([Ca]) in the sea urchin sperm flagellum, triggered by peptides secreted from the egg, and sperm motility. Determination of the structure and dynamics of the signaling pathway leading to these oscillations is a fundamental problem. However, a biochemically based formulation for the comprehension of the molecular mechanisms operating in the axoneme as a response to external stimulus is still lacking. Based on experiments on the S. purpuratus sea urchin spermatozoa, we propose a signaling network model where nodes are discrete variables corresponding to the pathway elements and the signal transmission takes place at discrete time intervals according to logical rules. The validity of this model is corroborated by reproducing previous empirically determined signaling features. Prompted by the model predictions we performed experiments which identified novel characteristics of the signaling pathway. We uncovered the role of a high voltage-activated channel as a regulator of the delay in the onset of fluctuations after activation of the signaling cascade. This delay time has recently been shown to be an important regulatory factor for sea urchin sperm reorientation. Another finding is the participation of a voltage-dependent calcium-activated channel in the determination of the period of the fluctuations. Furthermore, by analyzing the spread of network perturbations we find that it operates in a dynamically critical regime. Our work demonstrates that a coarse-grained approach to the dynamics of the signaling pathway is capable of revealing regulatory sperm navigation elements and provides insight, in terms of criticality, on the concurrence of the high robustness and adaptability that the reproduction processes are predicted to have developed

  12. Inducible galectins are expressed in the inflamed pharynx of the ascidian Ciona intestinalis.

    PubMed

    Vizzini, Aiti; Parrinello, Daniela; Sanfratello, Maria Antonietta; Salerno, Giuseppina; Cammarata, Matteo; Parrinello, Nicolò

    2012-01-01

    Although ascidians belong to a key group in chordate phylogenesis, amino acid sequences of Ciona intestinalis galectin-CRDs (CiLgals-a and -b) have been retained too divergent from vertebrate galectins. In the present paper, to contribute in disclosing Bi-CRD galectin evolution a novel attempt was carried out on CiLgals-a and -b CRDs phylogenetic analysis, and their involvement in ascidian inflammatory responses was shown. CiLgals resulted aligned with Bi-CRD galectins from vertebrates (Xenopus tropicalis, Gallus gallus, Mus musculus, Homo sapiens), cephalochordates (Branchiostoma floridae), echinoderms (Strongylocentrotus purpuratus) and a mono-CRD galectin from the ascidian Clavelina picta. The CiLgals-a N-terminal and C-terminal CRDs contain the signature sequence involved in carbohydrate binding, whereas the CiLgals-b C-CRD presents only three out of seven key aminoacids and it could not be suitable as sugar binding motif. Sequence similarity between clusters suggests an evolutionary model based on CRD domain gene duplication and sequence diversification. In particular CiLgals-b N-CRD and C-CRD were similar to each other and both grouped with the ascidian C. picta mono-CRD. Homology modeling process shows a CiLgals molecular structure superimposed to chicken and mouse galectins. The CiLgals-a and CiLgals-b genes were upregulated by LPS inoculation suggesting that they are inducible and expressed in the inflamed pharynx as revealed by real-time PCR analysis. Finally, in situ hybridization and immunohistochemical assays showed their localization in the inflamed tissues, while immunoblotting analysis indicated that CiLgals can form oligomers.

  13. Concordance and interaction of guanine nucleotide dissociation inhibitor (RhoGDI) with RhoA in oogenesis and early development of the sea urchin

    PubMed Central

    Zazueta-Novoa, Vanesa; Martínez-Cadena, Guadalupe; Wessel, Gary M.; Zazueta-Sandoval, Roberto; Castellano, Laura; García-Soto, Jesús

    2016-01-01

    Rho GTPases are Ras-related GTPases that regulate a variety of cellular processes. In the sea urchin Strongylocentrotus purpuratus, RhoA in the oocyte associates with the membrane of the cortical granules and directs their movement from the cytoplasm to the cell cortex during maturation to an egg. RhoA also plays an important role regulating the Na+-H+ exchanger activity which determines the internal pH of the cell during the first minutes of embryogenesis. We investigated how this activity may be regulated by a Guanine-nucleotide Dissociation Inhibitor (RhoGDI). The sequence of this RhoA regulatory protein was identified in the genome on the basis of its similarity to other RhoGDI species, especially for key segments in the formation of the isoprenyl-binding pocket and in interactions with the Rho GTPase. We examined the expression and the subcellular localization of RhoGDI during oogenesis and in different developmental stages. We found that RhoGDI mRNA levels were high in eggs and during cleavage divisions until blastula, when it disappeared, only to reappear in gastrula stage. RhoGDI localization overlaps the presence of RhoA during oogenesis and in embryonic development, reinforcing the regulatory premise of the interaction. By use of recombinant protein interactions in vitro, we also find that these two proteins selectively interact. These results support the hypothesis of a functional relationship in vivo and now enable mechanistic insight for the cellular and organellar rearrangements that occur during oogenesis and embryonic development. PMID:21492154

  14. Maternal exposure to estradiol and endocrine disrupting compounds alters the sensitivity of sea urchin embryos and the expression of an orphan steroid receptor.

    PubMed

    Roepke, Troy A; Chang, Ernest S; Cherr, Gary N

    2006-10-01

    Endocrine disrupting compounds (EDCs) are known to affect reproduction and development in marine invertebrates. In previous work, we have shown that developing sea urchin embryos were sensitive to estradiol and estrogenic EDCs at environmentally relevant concentrations in a tamoxifen-sensitive manner (Roepke et al. 2005. Aquat Toxicol 71:155-173). In this study, we report the effects of maternal exposure to EDCs on embryo sensitivity and regulation of an orphan steroid receptor in sea urchin eggs. Maternal exposures were conducted by injecting female Strongylocentrotus purpuratus sea urchins initiating oogenesis with two concentrations of estradiol, octylphenol, tributyltin and o, p-DDD for 8 weeks with an induced spawning before and after the injection cycle. Developing embryos were less sensitive to estradiol following maternal exposure to estradiol, octylphenol and DDD. The steroidogenesis inhibitor, spironolactone, and the aromatase inhibitor, formestane, affected normal sea urchin development with EC50 values of 18 and 2 microM, respectively. Binding of estradiol was demonstrated in homogenates supernatants of sea urchin embryos by filtration centrifugation and column chromatography, but saturation was not reached until 4-6 hr and was highly variable. Analysis of eggs from pre- and post-injection spawns using real-time Q-PCR for the mRNA of an orphan steroid receptor, SpSHR2, shows that receptor mRNA increased in eggs with estradiol, octylphenol and tributyltin but decreased with DDD. RIA showed that estradiol may be present during gastrulation. In summary, maternal exposure to estradiol and EDCs alters embryo sensitivity and regulates the expression of an orphan steroid receptor in the egg.

  15. MGEScan-non-LTR: computational identification and classification of autonomous non-LTR retrotransposons in eukaryotic genomes

    PubMed Central

    Rho, Mina; Tang, Haixu

    2009-01-01

    Computational methods for genome-wide identification of mobile genetic elements (MGEs) have become increasingly necessary for both genome annotation and evolutionary studies. Non-long terminal repeat (non-LTR) retrotransposons are a class of MGEs that have been found in most eukaryotic genomes, sometimes in extremely high numbers. In this article, we present a computational tool, MGEScan-non-LTR, for the identification of non-LTR retrotransposons in genomic sequences, following a computational approach inspired by a generalized hidden Markov model (GHMM). Three different states represent two different protein domains and inter-domain linker regions encoded in the non-LTR retrotransposons, and their scores are evaluated by using profile hidden Markov models (for protein domains) and Gaussian Bayes classifiers (for linker regions), respectively. In order to classify the non-LTR retrotransposons into one of the 12 previously characterized clades using the same model, we defined separate states for different clades. MGEScan-non-LTR was tested on the genome sequences of four eukaryotic organisms, Drosophila melanogaster, Daphnia pulex, Ciona intestinalis and Strongylocentrotus purpuratus. For the D. melanogaster genome, MGEScan-non-LTR found all known ‘full-length’ elements and simultaneously classified them into the clades CR1, I, Jockey, LOA and R1. Notably, for the D. pulex genome, in which no non-LTR retrotransposon has been annotated, MGEScan-non-LTR found a significantly larger number of elements than did RepeatMasker, using the current version of the RepBase Update library. We also identified novel elements in the other two genomes, which have only been partially studied for non-LTR retrotransposons. PMID:19762481

  16. In Silico Determination of the Effect of Multi-Target Drugs on Calcium Dynamics Signaling Network Underlying Sea Urchin Spermatozoa Motility

    PubMed Central

    Espinal-Enríquez, Jesús; Darszon, Alberto; Guerrero, Adán; Martínez-Mekler, Gustavo

    2014-01-01

    The motility of spermatozoa of both Lytechinus pictus and Strongylocentrotus purpuratus sea urchin species is modulated by the egg-derived decapeptide speract via an oscillatory [Ca2+]-dependent signaling pathway. Comprehension of this pathway is hence directly related to the understanding of regulated sperm swimming. Niflumic acid (NFA), a nonsteroidal anti-inflammatory drug alters several ion channels. Though unspecific, NFA profoundly affects how sea urchin sperm respond to speract, increasing the [Ca2+]i oscillation period, amplitude, peak and average level values of the responses in immobilized and swimming cells. A previous logical network model we developed for the [Ca2+] dynamics of speract signaling cascade in sea urchin sperm allows integrated dissection of individual and multiple actions of NFA. Among the channels affected by NFA are: hyperpolarization-activated and cyclic nucleotide gated Na+ channels (HCN), [Ca2+]-dependent Cl− channels (CaCC) and [Ca2+]-dependent K+ channels (CaKC), all present in the sea urchin genome. Here, using our model we investigated the effect of blocking in silico HCN and CaCC channels suggested by experiments. Regarding CaKC channels, arguments can be provided for either their blockage or activation by NFA. Our study yielded two scenarios compliant with experimental observations: i) under CaKC inhibition, this [Ca2+]-dependent K+ channel should be different from the Slo1 channel and ii) under activation of the CaKC channel, another [Ca2+] channel not considered previously in the network is required, such as the pH-dependent CatSper channel. Additionally, our findings predict cause-effect relations resulting from a selective inhibition of those channels. Knowledge of these relations may be of consequence for a variety of electrophysiological studies and have an impact on drug related investigations. Our study contributes to a better grasp of the network dynamics and suggests further experimental work. PMID:25162222

  17. Involvement of zinc in the regulation of pHi, motility, and acrosome reactions in sea urchin sperm

    PubMed Central

    1985-01-01

    When sperm of Strongylocentrotus purpuratus or Lytechinus pictus are diluted into seawater, motility is initiated; and when exposed to egg jelly, an acrosome reaction is induced. In the presence of a variety of structurally different metal chelators (0.1-1 mM EDTA, EGTA, phenanthroline, dipyridyl, cysteine, or dithiothreitol), motility initiation is delayed and the acrosome reaction is inhibited. Of the metals detected in the sperm of these two species, very low levels of Zn+2 (0.1 microM free Zn+2) uniquely prevent this chelator inhibition. L. pictus sperm concentrate 65Zn+2 from seawater, and EDTA removes 50% of the accumulated 65Zn+2 by 5 min. Since both sperm motility and acrosome reactions are in part regulated by intracellular pH (pHi), the effect of chelators on the sperm pHi was examined by using the fluorescent pH sensitive probe, 9-aminoacridine, EDTA depresses sperm pHi in both species, and 0.1 microM free Zn+2 reverses this pHi depression. When sperm are diluted into media that contain chelators, both NH4Cl and monensin (a Na+/H+ ionophore) increase the sperm pHi and reverse the chelator inhibition of sperm motility and acrosome reactions. The results of this study are consistent with the involvement of a trace metal (probably zinc) in the pHi regulation of sea urchin sperm and indicate a likely mechanism for the previously observed effects of chelators on sperm motility and acrosome reactions. PMID:3922992

  18. Identification of the sea urchin egg receptor for sperm using an antiserum raised against a fragment of its extracellular domain

    PubMed Central

    1992-01-01

    Sea urchin egg fertilization requires the species-specific interaction of molecules on the sperm and egg surfaces. Previously, we isolated an extracellular, 70-kD glycosylated fragment of the S. purpuratus egg receptor for sperm by treating the eggs with lysylendoproteinase C (Foltz, K. R., and W. J. Lennarz. 1990. J. Cell Biol. 111:2951-2959). To characterize the receptor further, we have generated a polyclonal antiserum (anti-70KL) against the purified 70-kD fragment. Anti-70KL was found to react with a single polypeptide of approximately 350 kD on Western blots, presumed to be the intact receptor, in an egg cell surface preparation. This polypeptide appeared to be tightly associated with the plasma membrane/vitelline layer complex, as it was released from these preparations only by detergent treatment. Immunofluorescence microscopy revealed that the receptor was distributed evenly over the egg surface. The anti-70KL was species specific both in its ability to recognize the egg surface protein and to inhibit sperm binding. Fab fragments generated from affinity-purified anti-70KL also bound to the egg surface and inhibited sperm binding in a concentration-dependent manner. Interestingly, treatment with Fabs caused a small percentage of eggs to undergo cortical granule exocytosis, even in the absence of external Ca2+. These results confirm earlier findings indicating that the receptor is a cell surface glycoprotein of high molecular weight that species specifically binds sperm. This antiserum provides a powerful tool for further investigation of gamete interactions and the structure of the sperm receptor. PMID:1309817

  19. Cis-Regulatory Control of the Nuclear Receptor Coup-TF Gene in the Sea Urchin Paracentrotus lividus Embryo

    PubMed Central

    Kalampoki, Lamprini G.; Flytzanis, Constantin N.

    2014-01-01

    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. PMID:25386650

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

    PubMed

    Kalampoki, Lamprini G; Flytzanis, Constantin N

    2014-01-01

    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.

  1. Molecular characterization, expression analysis of the myostatin gene and its association with growth traits in sea cucumber (Apostichopus japonicus).

    PubMed

    Li, Shilei; Zhou, Zunchun; Dong, Ying; Sun, Hongjuan; Gao, Shan; Chen, Zhong; Yang, Aifu; Liu, Weidong; Wang, Qingzhi

    2016-11-01

    Myostatin (MSTN), also referred to as growth and differentiation factor-8 (GDF-8), is a member of the transforming growth factor-β superfamily (TGF-β) and an important negative regulator for skeletal muscle development and growth in vertebrates. However, its function is not clear in invertebrates. In this study, we cloned and analyzed the MSTN gene (Aj-MSTN) from sea cucumber (Apostichopus japonicus). The full-length cDNA sequence of Aj-MSTN gene was composed of 2912bp, which contained a 5' UTR of 487bp, an ORF of 1356bp encoding 452 amino acids and a 3' UTR of 1069bp. The structure of Aj-MSTN included a putative signal peptide, a TGF-β propeptide domain and a conserved TGF-β domain. Phylogenetic analysis showed that the Aj-MSTN gene was clustered in the same subgroup with the MSTN-like gene found in Strongylocentrotus purpuratus. Quantitative real-time PCR detection results indicated that the Aj-MSTN gene expressed widely in adult tissues and the highest expression level was observed in the body wall. At different developmental stages, the expression levels were increased significantly at early auricularia and doliolaria stages, and reached the peak at juvenile stage. Six SNPs were identified in 5' flanking region and exons of the Aj-MSTN gene. Association analysis showed that SNP-1, SNP-2 and SNP-4 had significant effects on dry body weight. The results suggested that Aj-MSTN gene could be used as a candidate gene for the selective breeding of A. japonicus.

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

    PubMed

    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.

  3. Unique system of photoreceptors in sea urchin tube feet

    PubMed Central

    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

  4. In silico determination of the effect of multi-target drugs on calcium dynamics signaling network underlying sea urchin spermatozoa motility.

    PubMed

    Espinal-Enríquez, Jesús; Darszon, Alberto; Guerrero, Adán; Martínez-Mekler, Gustavo

    2014-01-01

    The motility of spermatozoa of both Lytechinus pictus and Strongylocentrotus purpuratus sea urchin species is modulated by the egg-derived decapeptide speract via an oscillatory [Ca2+]-dependent signaling pathway. Comprehension of this pathway is hence directly related to the understanding of regulated sperm swimming. Niflumic acid (NFA), a nonsteroidal anti-inflammatory drug alters several ion channels. Though unspecific, NFA profoundly affects how sea urchin sperm respond to speract, increasing the [Ca2+]i oscillation period, amplitude, peak and average level values of the responses in immobilized and swimming cells. A previous logical network model we developed for the [Ca2+] dynamics of speract signaling cascade in sea urchin sperm allows integrated dissection of individual and multiple actions of NFA. Among the channels affected by NFA are: hyperpolarization-activated and cyclic nucleotide gated Na+ channels (HCN), [Ca2+]-dependent Cl- channels (CaCC) and [Ca2+]-dependent K+ channels (CaKC), all present in the sea urchin genome. Here, using our model we investigated the effect of blocking in silico HCN and CaCC channels suggested by experiments. Regarding CaKC channels, arguments can be provided for either their blockage or activation by NFA. Our study yielded two scenarios compliant with experimental observations: i) under CaKC inhibition, this [Ca2+]-dependent K+ channel should be different from the Slo1 channel and ii) under activation of the CaKC channel, another [Ca2+] channel not considered previously in the network is required, such as the pH-dependent CatSper channel. Additionally, our findings predict cause-effect relations resulting from a selective inhibition of those channels. Knowledge of these relations may be of consequence for a variety of electrophysiological studies and have an impact on drug related investigations. Our study contributes to a better grasp of the network dynamics and suggests further experimental work.

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

    USGS Publications Warehouse

    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.

  6. Two cis elements collaborate to spatially repress transcription from a sea urchin promoter

    NASA Technical Reports Server (NTRS)

    Frudakis, T. N.; Wilt, F.

    1995-01-01

    The expression pattern of many territory-specific genes in metazoan embryos is maintained by an active process of negative spatial regulation. However, the mechanism of this strategy of gene regulation is not well understood in any system. Here we show that reporter constructs containing regulatory sequence for the SM30-alpha gene of Stronglyocentrotus purpuratus are expressed in a pattern congruent with that of the endogenous SM30 gene(s), largely as a result of active transcriptional repression in cell lineages in which the gene is not normally expressed. Chloramphenicol acetyl transferase assays of deletion constructs from the 2600-bp upstream region showed that repressive elements were present in the region from -1628 to -300. In situ hybridization analysis showed that the spatial fidelity of expression was severely compromised when the region from -1628 to -300 was deleted. Two highly repetitive sequence motifs, (G/A/C)CCCCT and (T/C)(T/A/C)CTTTT(T/A/C), are present in the -1628 to -300 region. Representatives of these elements were analyzed by gel mobility shift experiments and were found to interact specifically with protein in crude nuclear extracts. When oligonucleotides containing either sequence element were co-injected with a correctly regulated reporter as potential competitors, the reporter was expressed in inappropriate cells. When composite oligonucleotides, containing both sequence elements, were fused to a misregulated reporter, the expression of the reporter in inappropriate cells was suppressed. Comparison of composite oligonucleotides with oligonucleotides containing single constituent elements show that both sequence elements are required for effective spatial regulation. Thus, both individual elements are required, but only a composite element containing both elements is sufficient to function as a tissue-specific repressive element.

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

    SciTech Connect

    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.

  8. Curve fitting toxicity test data: Which comes first, the dose response or the model?

    SciTech Connect

    Gully, J.; Baird, R.; Bottomley, J.

    1995-12-31

    The probit model frequently does not fit the concentration-response curve of NPDES toxicity test data and non-parametric models must be used instead. The non-parametric models, trimmed Spearman-Karber, IC{sub p}, and linear interpolation, all require a monotonic concentration-response. Any deviation from a monotonic response is smoothed to obtain the desired concentration-response characteristics. Inaccurate point estimates may result from such procedures and can contribute to imprecision in replicate tests. The following study analyzed reference toxicant and effluent data from giant kelp (Macrocystis pyrifera), purple sea urchin (Strongylocentrotus purpuratus), red abalone (Haliotis rufescens), and fathead minnow (Pimephales promelas) bioassays using commercially available curve fitting software. The purpose was to search for alternative parametric models which would reduce the use of non-parametric models for point estimate analysis of toxicity data. Two non-linear models, power and logistic dose-response, were selected as possible alternatives to the probit model based upon their toxicological plausibility and ability to model most data sets examined. Unlike non-parametric procedures, these and all parametric models can be statistically evaluated for fit and significance. The use of the power or logistic dose response models increased the percentage of parametric model fits for each protocol and toxicant combination examined. The precision of the selected non-linear models was also compared with the EPA recommended point estimation models at several effect.levels. In general, precision of the alternative models was equal to or better than the traditional methods. Finally, use of the alternative models usually produced more plausible point estimates in data sets where the effects of smoothing and non-parametric modeling made the point estimate results suspect.

  9. Oxidative damage and cellular defense mechanisms in sea urchin models of aging.

    PubMed

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

    2013-10-01

    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 because of 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 life span. Levels of protein carbonyls and 4-hydroxynonenal measured in tissues (muscle, nerve, esophagus, gonad, coelomocytes, ampullae) and 8-hydroxy-2'-deoxyguanosine 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.

  10. NG peptides: a novel family of neurophysin-associated neuropeptides.

    PubMed

    Elphick, Maurice R

    2010-06-15

    Neurophysins are prohormone-derived polypeptides that are required for biosynthesis of the neurohypophyseal hormones vasopressin and oxytocin. Accordingly, mutations in the neurophysin domain of the human vasopressin gene can cause diabetes insipidus. The association of neurophysins with vasopressin/oxytocin-type peptides dates back to the common ancestor of bilaterian animals and until recently it was thought to be unique. This textbook perspective on neurophysins changed with the discovery of a gene in the sea urchin Strongylocentrotus purpuratus (phylum Echinodermata) encoding a precursor protein comprising a neurophysin domain in association with NGFFFamide, a myoactive neuropeptide that is structurally unrelated to vasopressin/oxytocin-type neuropeptides (Elphick, M.R., Rowe, M.L., 2009. NGFFFamide and echinotocin: structurally unrelated myoactive neuropeptides derived from neurophysin-containing precursors in sea urchins. J. Exp. Biol. 212, 1067-1077). What is not known, however, is when and how the association of neurophysin with NGFFFamide-like neuropeptides originated. Here I report the discovery of genes encoding proteins comprising a neurophysin domain in association with putative NGFFFamide-like peptides in the hemichordate Saccoglossus kowalevskii (NGFWNamide and NGFYNamide) and in the cephalochordate Branchiostoma floridae (SFRNGVamide). Together with NGFFFamide, these peptides constitute a novel family of neuropeptides in invertebrate deuterostomes that are derived from neurophysin-containing precursors and that have the sequence motif NG - "NG peptides". Genes encoding NG peptides in association with neurophysin were not found in protostomes, urochordates or vertebrates. Interestingly, however, SFRNGVamide is identical to the N-terminal region of neuropeptide S, a peptide that modulates arousal and anxiety in mammals, whilst NGFFFamide shares sequence similarity with SIFamide (AYRKPPFNGSIFamide), a neuropeptide that regulates sexual behaviour in

  11. Transcriptomic responses to seawater acidification among sea urchin populations inhabiting a natural pH mosaic.

    PubMed

    Evans, Tyler G; Pespeni, Melissa H; Hofmann, Gretchen E; Palumbi, Stephen R; Sanford, Eric

    2017-01-31

    Increasing awareness of spatial and temporal variation in ocean pH suggests some marine populations may be adapted to local pH regimes and will therefore respond differently to present-day pH variation and to long-term ocean acidification. In the Northeast Pacific Ocean, differences in the strength of coastal upwelling cause latitudinal variation in prevailing pH regimes that are hypothesized to promote local adaptation and unequal pH tolerance among resident populations. In this study, responses to experimental seawater acidification were compared among six populations of purple sea urchins (Strongylocentrotus purpuratus) inhabiting areas that differ in their frequency of low pH exposure and that prior research suggests are locally adapted to seawater pH. Transcriptomic analyses demonstrate urchin populations most frequently exposed to low pH seawater responded to experimental acidification by expressing genes within major ATP producing pathways at greater levels than populations encountering low pH less often. Multiple genes within the tricarboxylic acid cycle, electron transport chain, and fatty acid beta oxidation pathways were up-regulated in urchin populations experiencing low pH conditions most frequently. These same metabolic pathways were significantly over-represented among genes both expressed in a population-specific manner and putatively under selection to enhance low pH tolerance. Collectively, these data suggest natural selection is acting on metabolic gene networks in order to redirect ATP toward acid-base regulatory processes and enhance tolerance of seawater acidification. As a trade-off, marine populations more tolerant of low pH may have less energy to put toward other aspects of fitness and to respond to additional ocean change. This article is protected by copyright. All rights reserved.

  12. Comparative Study of Regulatory Circuits in Two Sea Urchin Species Reveals Tight Control of Timing and High Conservation of Expression Dynamics

    PubMed Central

    Gildor, Tsvia; Ben-Tabou de-Leon, Smadar

    2015-01-01

    Accurate temporal control of gene expression is essential for normal development and must be robust to natural genetic and environmental variation. Studying gene expression variation within and between related species can delineate the level of expression variability that development can tolerate. Here we exploit the comprehensive model of sea urchin gene regulatory networks and generate high-density expression profiles of key regulatory genes of the Mediterranean sea urchin, Paracentrotus lividus (Pl). The high resolution of our studies reveals highly reproducible gene initiation times that have lower variation than those of maximal mRNA levels between different individuals of the same species. This observation supports a threshold behavior of gene activation that is less sensitive to input concentrations. We then compare Mediterranean sea urchin gene expression profiles to those of its Pacific Ocean relative, Strongylocentrotus purpuratus (Sp). These species shared a common ancestor about 40 million years ago and show highly similar embryonic morphologies. Our comparative analyses of five regulatory circuits operating in different embryonic territories reveal a high conservation of the temporal order of gene activation but also some cases of divergence. A linear ratio of 1.3-fold between gene initiation times in Pl and Sp is partially explained by scaling of the developmental rates with temperature. Scaling the developmental rates according to the estimated Sp-Pl ratio and normalizing the expression levels reveals a striking conservation of relative dynamics of gene expression between the species. Overall, our findings demonstrate the ability of biological developmental systems to tightly control the timing of gene activation and relative dynamics and overcome expression noise induced by genetic variation and growth conditions. PMID:26230518

  13. Regulated proteolysis by cortical granule serine protease 1 at fertilization.

    PubMed

    Haley, Sheila A; Wessel, Gary M

    2004-05-01

    Cortical granules are specialized organelles whose contents interact with the extracellular matrix of the fertilized egg to form the block to polyspermy. In sea urchins, the granule contents form a fertilization envelope (FE), and this construction is critically dependent upon protease activity. An autocatalytic serine protease, cortical granule serine protease 1 (CGSP1), has been identified in the cortical granules of Strongylocentrotus purpuratus eggs, and here we examined the regulation of the protease activity and tested potential target substrates of CGSP1. We found that CGSP1 is stored in its full-length, enzymatically quiescent form in the granule, and is inactive at pH 6.5 or below. We determined the pH of the cortical granule by fluorescent indicators and micro-pH probe measurements and found the granules to be pH 5.5, a condition inhibitory to CGSP1 activity. Exposure of the protease to the pH of seawater (pH 8.0) at exocytosis immediately activates the protease. Activation of eggs at pH 6.5 or lower blocks activation of the protease and the resultant FE phenotypes are indistinguishable from a protease-null phenotype. We find that native cortical granule targets of the protease are beta-1,3 glucanase, ovoperoxidase, and the protease itself, but the structural proteins of the granule are not proteolyzed by CGSP1. Whole mount immunolocalization experiments demonstrate that inhibition of CGSP1 activity affects the localization of ovoperoxidase but does not alter targeting of structural proteins to the FE. The mistargeting of ovoperoxidase may lead to spurious peroxidative cross-linking activity and contribute to the lethality observed in protease-null cells. Thus, CGSP1 is proteolytically active only when secreted, due to the low pH of the cortical granules, and it has a small population of targets for cleavage within the cortical granules.

  14. Experimental ocean acidification alters the allocation of metabolic energy

    PubMed Central

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

    2015-01-01

    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. PMID:25825763

  15. Regional differentiation of the sperm surface as studied with 125I- diiodofluorescein isothiocyanate, an impermeant reagent that allows isolation of the labeled components

    PubMed Central

    1979-01-01

    The regional differentiation of the sperm surface has been studied with the aid of a novel covalent labeling technique that permits concurrent cytological, biochemical, and immunological analyses. For these studies isothiocyanate derivatives of fluorescein (FITC) and diiodofluorescein (IFC) were employed: the latter can be prepared with radioiodine to high specific activity (125IFC) and is an impermeant reagent for the erythrocyte surface. Sperm of sea urchin (Strongylocentrotus purpuratus), medaka )Oryzias latipes), and golden hamster bind the fluorescent chromophores with a nonuniform distribution, most of the fluorescence being associated with the midpiece. The radioactive derivative 125IFC permits an analysis of the proteins that are responsible for most of the binding. Additionally, 125 IFC-labeled sperm are capable of fertilizing eggs, as assessed by autoradiography. That IFC labels the surface of the sperm was inferred from the following: (a) the labeling of the surfaces of other cells by fluorescein isothiocyanate and its derivatives; (b) the agglutination of labeled sperm by antibodies directed against IFC; (c) the use of peroxidase-dependent immunocytochemical reaction using anti-IFC antibodies, with analysis by electron microscopy; and (d) extraction of labeled sea urchin sperm with Triton X-100 under conditions that preferentially solubilize the plasma membrane. The antiserum directed against IFC was used to isolate the labeled surface components from Triton X-100 extracts of whole sperm, by immunoprecipitation, with Staphylococcus-A protein serving as a coprecipitant. The results support previous data showing that the sperm surface is a heterogeneous mosaic of restricted domains, one notable zone being the midpiece, where common molecular properties may be shared by sperm with distinctly different morphologies. In addition, IFC-mediated covalent alteration of specific cell surface proteins may be used to label, to identify, and, with the use of anti

  16. Niflumic acid disrupts marine spermatozoan chemotaxis without impairing the spatiotemporal detection of chemoattractant gradients.

    PubMed

    Guerrero, Adán; Espinal, Jesús; Wood, Christopher D; Rendón, Juan M; Carneiro, Jorge; Martínez-Mekler, Gustavo; Darszon, Alberto

    2013-03-15

    In many broadcast-spawning marine organisms, oocytes release chemicals that guide conspecific spermatozoa towards them through chemotaxis. In the sea urchin Lytechinus pictus, the chemoattractant peptide speract triggers a train of fluctuations of intracellular Ca(2+) concentration in the sperm flagella. Each transient Ca(2+) elevation leads to a momentary increase in flagellar bending asymmetry, known as a chemotactic turn. Furthermore, chemotaxis requires a precise spatiotemporal coordination between the Ca(2+)-dependent turns and the form of chemoattractant gradient. Spermatozoa that perform Ca(2+)-dependent turns while swimming down the chemoattractant gradient, and conversely suppress turning events while swimming up the gradient, successfully approach the center of the gradient. Previous experiments in Strongylocentrotus purpuratus sea urchin spermatozoa showed that niflumic acid (NFA), an inhibitor of several ion channels, drastically altered the speract-induced Ca(2+) fluctuations and swimming patterns. In this study, mathematical modeling of the speract-dependent Ca(2+) signaling pathway suggests that NFA, by potentially affecting hyperpolarization-activated and cyclic nucleotide-gated channels, Ca(2+)-regulated Cl(-) channels and/or Ca(2+)-regulated K(+) channels, may alter the temporal organization of Ca(2+) fluctuations, and therefore disrupt chemotaxis. We used a novel automated method for analyzing sperm behavior and we identified that NFA does indeed disrupt chemotactic responses of L. pictus spermatozoa, although the temporal coordination between the Ca(2+)-dependent turns and the form of chemoattractant gradient is unaltered. Instead, NFA disrupts sperm chemotaxis by altering the arc length traveled during each chemotactic turning event. This alteration in the chemotactic turn trajectory disorientates spermatozoa at the termination of the turning event. We conclude that NFA disrupts chemotaxis without affecting how the spermatozoa decode

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

    PubMed Central

    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 NH2-terminus of the extracellular domain of the sperm receptor is rich in cysteine residues. Studies with cross-linking agents of various length and hydrophobicity suggest that no other major protein is tightly associated with the receptor. Given the multimeric structure of the receptor, we investigated the effect of disulfide bond reduction on its biological activity. Because in quantitative bioassays fertilization was found to be inhibited by treatment of eggs with 5 mM dithiothreitol, we undertook more direct studies of the effect of reduction on properties of the receptor. First, we studied the effect of addition of isolated, pure receptor on fertilization. Whereas the non-reduced, native receptor complex inhibited fertilization in a dose- dependent manner, the reduced and alkylated receptor was inactive. Second, we tested the ability of the isolated receptor to mediate binding of acrosome-reacted sperm to polystyrene beads. Whereas beads coated with native receptor bound sperm, those containing reduced and alkylated receptor did not. Thus, these results demonstrate that the biologically active form of the sea urchin sperm receptor consists only of 350 kD subunits and that these must be linked as a multimer via disulfide bonds to produce a complex that is functional in sperm recognition and binding. PMID:8188748

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

    PubMed

    Heijerick, D G; Regoli, L; Stubblefield, W

    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(4)(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(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(2)MoO(4)·2H(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(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(5,50%) (median hazardous concentration affecting 5% of the species) of 5.74(mg Mo)/L was derived with the statistical extrapolation approach, a value that can be used for national and

  19. Sequential Logic Model Deciphers Dynamic Transcriptional Control of Gene Expressions

    PubMed Central

    Yeo, Zhen Xuan; Wong, Sum Thai; Arjunan, Satya Nanda Vel; Piras, Vincent; Tomita, Masaru; Selvarajoo, Kumar; Giuliani, Alessandro; Tsuchiya, Masa

    2007-01-01

    Background Cellular signaling involves a sequence of events from ligand binding to membrane receptors through transcription factors activation and the induction of mRNA expression. The transcriptional-regulatory system plays a pivotal role in the control of gene expression. A novel computational approach to the study of gene regulation circuits is presented here. Methodology Based on the concept of finite state machine, which provides a discrete view of gene regulation, a novel sequential logic model (SLM) is developed to decipher control mechanisms of dynamic transcriptional regulation of gene expressions. The SLM technique is also used to systematically analyze the dynamic function of transcriptional inputs, the dependency and cooperativity, such as synergy effect, among the binding sites with respect to when, how much and how fast the gene of interest is expressed. Principal Findings SLM is verified by a set of well studied expression data on endo16 of Strongylocentrotus purpuratus (sea urchin) during the embryonic midgut development. A dynamic regulatory mechanism for endo16 expression controlled by three binding sites, UI, R and Otx is identified and demonstrated to be consistent with experimental findings. Furthermore, we show that during transition from specification to differentiation in wild type endo16 expression profile, SLM reveals three binary activities are not sufficient to explain the transcriptional regulation of endo16 expression and additional activities of binding sites are required. Further analyses suggest detailed mechanism of R switch activity where indirect dependency occurs in between UI activity and R switch during specification to differentiation stage. Conclusions/Significance The sequential logic formalism allows for a simplification of regulation network dynamics going from a continuous to a discrete representation of gene activation in time. In effect our SLM is non-parametric and model-independent, yet providing rich biological

  20. Calbindin-D32k is localized to a subpopulation of neurons in the nervous system of the sea cucumber Holothuria glaberrima (Echinodermata).

    PubMed

    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.

  1. Meprins, membrane-bound and secreted astacin metalloproteinases

    PubMed Central

    Sterchi, Erwin E.; Stöcker, Walter; Bond, Judith S.

    2008-01-01

    The astacins are a subfamily of the metzincin superfamily of metalloproteinases. The first to be characterized was the crayfish enzyme astacin. To date more than 200 members of this family have been identified in species ranging from bacteria to humans. Astacins are involved in developmental morphogenesis, matrix assembly, tissue differentiation and digestion. Family members include the procollagen C-proteinase (BMP1, bone morphogenetic protein 1), tolloid and mammalian tolloid-like, HMP (Hydra vulgaris metalloproteinase), sea urchin BP10 (blastula protein) and SPAN (Strongylocentrotus purpuratus astacin), the ‘hatching’ subfamily comprising alveolin, ovastacin, LCE, HCE (‘low’ and ‘high’ choriolytic enzymes), nephrosin (from carp head kidney), UVS.2 from frog, and the meprins. In the human and mouse genomes, there are six astacin family genes (two meprins, three BMP1/tolloid-like, one ovastacin), but in Caenorhabditis elegans there are 40. Meprins are the only astacin proteinases that function on the membrane and extracellularly by virtue of the fact that they can be membrane-bound or secreted. They are unique in their domain structure and covalent subunit dimerization, oligomerization propensities, and expression patterns. They are normally highly regulated at the transcriptional and post-translational levels, localize to specific membranes or extracellular spaces, and can hydrolyse biologically active peptides, cytokines, extracellular matrix (ECM) proteins and cell-surface proteins. The in vivo substrates of meprins are unknown, but the abundant expression of these proteinases in the epithelial cells of the intestine, kidney and skin provide clues to their functions. PMID:18783725

  2. SM50 Repeat-Polypeptides Self-Assemble into Discrete Matrix Subunits and Promote Appositional Calcium Carbonate Crystal Growth during Sea Urchin Tooth Biomineralization

    PubMed Central

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

    2015-01-01

    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

  3. Distribution and evolution of the serine/aspartate racemase family in invertebrates.

    PubMed

    Uda, Kouji; Abe, Keita; Dehara, Yoko; Mizobata, Kiriko; Sogawa, Natsumi; Akagi, Yuki; Saigan, Mai; Radkov, Atanas D; Moe, Luke A

    2016-02-01

    Free D-amino acids have been found in various invertebrate phyla, while amino acid racemase genes have been identified in few species. The purpose of this study is to elucidate the distribution, function, and evolution of amino acid racemases in invertebrate animals. We searched the GenBank databases, and found 11 homologous serine racemase genes from eight species in eight different invertebrate phyla. The cloned genes were identified based on their maximum activity as Acropora millepora (Cnidaria) serine racemase (SerR) and aspartate racemase (AspR), Caenorhabditis elegans (Nematoda) SerR, Capitella teleta (Annelida) SerR, Crassostrea gigas (Mollusca) SerR and AspR, Dugesia japonica (Platyhelminthes) SerR, Milnesium tardigradum (Tardigrada) SerR, Penaeus monodon (Arthropoda) SerR and AspR and Strongylocentrotus purpuratus (Echinodermata) AspR. We found that Acropora, Aplysia, Capitella, Crassostrea and Penaeus had two amino acid racemase paralogous genes and these paralogous genes have evolved independently by gene duplication at their recent ancestral species. The transcriptome analyses using available SRA data and enzyme kinetic data suggested that these paralogous genes are expressed in different tissues and have different functions in vivo. Phylogenetic analyses clearly indicated that animal SerR and AspR are not separated by their particular racemase functions and form a serine/aspartate racemase family cluster. Our results revealed that SerR and AspR are more widely distributed among invertebrates than previously known. Moreover, we propose that the triple serine loop motif at amino acid positions 150-152 may be responsible for the large aspartate racemase activity and the AspR evolution from SerR.

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

    PubMed Central

    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

  5. Molecular paleoecology: using gene regulatory analysis to address the origins of complex life cycles in the late Precambrian.

    PubMed

    Dunn, Ewan F; Moy, Vanessa N; Angerer, Lynne M; Angerer, Robert C; Morris, Robert L; Peterson, Kevin J

    2007-01-01

    Molecular paleoecology is the application of molecular data to test hypotheses made by paleoecological scenarios. Here, we use gene regulatory analysis to test between two competing paleoecological scenarios put forth to explain the evolution of complex life cycles. The first posits that early bilaterians were holobenthic, and the evolution of macrophagous grazing drove the exploitation of the pelagos by metazoan eggs and embryos, and eventually larvae. The alternative hypothesis predicts that early bilaterians were holopelagic, and new adult stages were added on when these holopelagic forms began to feed on the benthos. The former hypothesis predicts that the larvae of protostomes and deuterostomes are not homologous, with the implication that larval-specific structures, including the apical organ, are the products of convergent evolution, whereas the latter hypothesis predicts homology of larvae, specifically homology of the apical organ. We show that in the sea urchin, Strongylocentrotus purpuratus, the transcription factors NK2.1 and HNF6 are necessary for the correct spatial expression profiles of five different cilia genes. All of these genes are expressed exclusively in the apical plate after the mesenchyme-blastula stage in cells that also express NK2.1 and HNF6. In addition, abrogation of SpNK2.1 results in embryos that lack the apical tuft. However, in the red abalone, Haliotis rufescens, NK2.1 and HNF6 are not expressed in any cells that also express these same five cilia genes. Nonetheless, like the sea urchin, the gastropod expresses both NK2.1 and FoxA around the stomodeum and foregut, and FoxA around the proctodeum. As we detected no similarity in the development of the apical tuft between the sea urchin and the abalone, these molecular data are consistent with the hypothesis that the evolution of mobile, macrophagous metazoans drove the evolution of complex life cycles multiple times independently in the late Precambrian.

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

    PubMed

    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

  7. Phylogeny of Echinoderm Hemoglobins

    PubMed Central

    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

    Background 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. Results 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. Conclusion 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

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

    PubMed Central

    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

  9. Expression pattern of Brachyury and Not in the sea urchin: comparative implications for the origins of mesoderm in the basal deuterostomes.

    PubMed

    Peterson, K J; Harada, Y; Cameron, R A; Davidson, E H

    1999-03-15

    This work concerns the expression of two transcription factors during the development of the sea urchin Strongylocentrotus purpuratus: SpNot, the orthologue of the vertebrate Not gene, and SpBra, the orthologue of the vertebrate Brachyury gene. SpNot transcripts are detected by in situ hybridization in the vegetal plate at the mesenchyme-blastula stage. Later the gene is expressed in the secondary mesenchyme, but expression is no longer detectable after gastrulation. SpNot is upregulated during larval development, in the invaginating vestibule of the adult rudiment. Transcripts are also found in several larva-specific tissues, including the epaulets, blastocoelar cells, and pigment cells. SpBra also displays a discontinuous pattern of expression. Much like SpNot, this gene is expressed during embryogenesis in the embryonic vegetal plate and secondary mesenchyme founder cells, and expression is then extinguished. The gene is upregulated over a week later in the feeding larva, in the vestibule of the adult rudiment. In contrast to SpNot, SpBra is also expressed in the mesoderm of both left and right hydrocoels, and it is not expressed in any larva-specific tissues. We compare the spatial expression profile determined in this study with that of the orthologous Brachyury gene in an indirectly developing enteropneust hemichordate, a representative of the sister group to the echinoderms within the deuterostomes. These observations illuminate the genetic basis underlying the process of maximal indirect development in basal deuterostomes. Finally, Brachyury appears to be an excellent marker for the progeny of the set-aside cells of the sea urchin embryo.

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

    PubMed

    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.

  11. Gene expression and enzyme activities of the sodium pump during sea urchin development: implications for indices of physiological state.

    PubMed

    Marsh, A G; LeongPKK; Manahan, T

    2000-10-01

    The sodium pump consumes a large portion of the metabolic energy (40%) in sea urchin larvae. Understanding the developmental regulation of ion pumps is important for assessing the physiological state of embryos and larvae. We sequenced a partial cDNA clone (1769 bp) from the sea urchin Strongylocentrotus purpuratus and found it to contain the C-terminal portion of an open reading frame coding for 195 amino acids that exhibited high sequence similarity (89%) to invertebrate alpha-subunits of the Na+,K+-ATPase sodium pump. Northern blots using the 3' untranslated region of this cDNA specifically recognized a 4.6-kbp transcript under high stringency. During embryonic development, a rapid increase in levels of this mRNA transcript during gastrulation (25 h postfertilization) was paralleled by a concomitant increase in the total enzymatic activity of Na+,K+-ATPase. Expression of this subunit during gastrulation increased to a maximum at 36 h, followed by a rapid decline to trace levels by 60 h. The rate of removal of the transcript from the total RNA pool after 36 h closely followed a first-order exponential decay model (r2= 0.988), equivalent to a degradation rate of 7.8% h(-1). By 83 h, transcription of the alpha-subunit gene was low, yet sodium pump activity remained high. Molecular assays for the expression of this gene would underestimate sodium pump activities for assessing physiological state because of the temporal separation between maximal gene expression in a gastrula and maximal enzyme activities in the later larval stage. This finding illustrates the difficulty of using molecular probes for assessing the physiological state of invertebrate larvae.

  12. Concordance and interaction of guanine nucleotide dissociation inhibitor (RhoGDI) with RhoA in oogenesis and early development of the sea urchin.

    PubMed

    Zazueta-Novoa, Vanesa; Martínez-Cadena, Guadalupe; Wessel, Gary M; Zazueta-Sandoval, Roberto; Castellano, Laura; García-Soto, Jesús

    2011-04-01

    Rho GTPases are Ras-related GTPases that regulate a variety of cellular processes. In the sea urchin Strongylocentrotus purpuratus, RhoA in the oocyte associates with the membrane of the cortical granules and directs their movement from the cytoplasm to the cell cortex during maturation to an egg. RhoA also plays an important role regulating the Na(+) -H(+) exchanger activity, which determines the internal pH of the cell during the first minutes of embryogenesis. We investigated how this activity may be regulated by a guanine-nucleotide dissociation inhibitor (RhoGDI). The sequence of this RhoA regulatory protein was identified in the genome on the basis of its similarity to other RhoGDI species, especially for key segments in the formation of the isoprenyl-binding pocket and in interactions with the Rho GTPase. We examined the expression and the subcellular localization of RhoGDI during oogenesis and in different developmental stages. We found that RhoGDI mRNA levels were high in eggs and during cleavage divisions until blastula, when it disappeared, only to reappear in gastrula stage. RhoGDI localization overlaps the presence of RhoA during oogenesis and in embryonic development, reinforcing the regulatory premise of the interaction. By use of recombinant protein interactions in vitro, we also find that these two proteins selectively interact. These results support the hypothesis of a functional relationship in vivo and now enable mechanistic insight for the cellular and organelle rearrangements that occur during oogenesis and embryonic development.

  13. Oogenesis: single cell development and differentiation.

    PubMed

    Song, Jia L; Wong, Julian L; Wessel, Gary M

    2006-12-01

    Oocytes express a unique set of genes that are essential for their growth, for meiotic recombination and division, for storage of nutrients, and for fertilization. We have utilized the newly sequenced genome of Strongylocentrotus purpuratus to identify genes that help the oocyte accomplish each of these tasks. This study emphasizes four classes of genes that are specialized for oocyte function: (1) Transcription factors: many of these factors are not significantly expressed in embryos, but are shared by other adult tissues, namely the ovary, testis, and gut. (2) Meiosis: A full set of meiotic genes is present in the sea urchin, including those involved in cohesion, in synaptonemal complex formation, and in meiotic recombination. (3) Yolk uptake and storage: Nutrient storage for use during early embryogenesis is essential to oocyte function in most animals; the sea urchin accomplishes this task by using the major yolk protein and a family of accessory proteins called YP30. Comparison of the YP30 family members across their conserved, tandem fasciclin domains with their intervening introns reveals an incongruence in the evolution of its major clades. (4) Fertilization: This set of genes includes many of the cell surface proteins involved in sperm interaction and in the physical block to polyspermy. The majority of these genes are active only in oocytes, and in many cases, their anatomy reflects the tandem repeating interaction domains essential for the function of these proteins. Together, the expression profile of these four gene classes highlights the transitions of the oocyte from a stem cell precursor, through stages of development, to the clearing and re-programming of gene expression necessary to transition from oocyte, to egg, to embryo.

  14. Centrocins: isolation and characterization of novel dimeric antimicrobial peptides from the green sea urchin, Strongylocentrotus droebachiensis.

    PubMed

    Li, Chun; Haug, Tor; Moe, Morten K; Styrvold, Olaf B; Stensvåg, Klara

    2010-09-01

    As immune effector molecules, antimicrobial peptides (AMPs) play an important role in the invertebrate immune system. Here, we present two novel AMPs, named centrocins 1 (4.5kDa) and 2 (4.4kDa), purified from coelomocyte extracts of the green sea urchin, Strongylocentrotus droebachiensis. The native peptides are cationic and show potent activities against Gram-positive and Gram-negative bacteria. The centrocins have an intramolecular heterodimeric structure, containing a heavy chain (30 amino acids) and a light chain (12 amino acids). The cDNA encoding the peptides and genomic sequences were cloned and sequenced. One putative isoform (centrocin 1b) was identified and one intron was found in the genes coding for the centrocins. The full length protein sequence of centrocin 1 consists of 119 amino acids, whereas centrocin 2 consists of 118 amino acids which both include a preprosequence of 51 or 50 amino acids for centrocins 1 and 2, respectively, and an interchain of 24 amino acids between the heavy and light chain. The difference of molecular mass between the native centrocins and the deduced sequences from cDNA indicates that the native centrocins contain a post-translational brominated tryptophan. In addition, two amino acids at the C-terminal, Gly-Arg, were removed from the light chains during the post-translational processing. The separate peptide chains of centrocin 1 were synthesized and the heavy chain alone was shown to be sufficient for antimicrobial activity. The genome of the closely related species, the purple sea urchin (S. purpuratus), was shown to contain two putative proteins with high similarity to the centrocins.

  15. Molecular characterization and expression profile of MAP2K1ip1/MP1 gene from tiger shrimp, Penaeus monodon.

    PubMed

    Yang, Lishi; Liu, Xianjun; Huang, Jianhua; Yang, Qibin; Qiu, Lihua; Liu, Wenjing; Jiang, Shigui

    2012-05-01

    MAPK kinase 1 interacting protein 1 (MAP2K1ip1) is an important scaffold proteins of the mitogen-activated protein kinase (MAPK) pathway that form an active signaling module and enhance the specificity and spatiality of MAPK signaling. In the present study, we identified and characterized a MAP2K1ip1 cDNA from tiger shrimp Penaeus monodon (designated as PmMAP2K1ip1). The open reading frame of PmMAP2K1ip1 is 372 bp encoding 123 amino-acid residues with a MAPK interaction domain. The predicted PmMAP2Kip1 protein is 13.6 KDa with the theoretical isoelectric point of 6.3. PmMAP2K1ip1 shared the highest amino acid with Nasonia vitripennis and Strongylocentrotus purpuratus, at 48% and 47.5%, respectively. Phylogenic analysis shows PmMAP2Kip1 is clustering with SpMAP2Kip1, and close to the group of MAP2Kip1s from insect. Furthermore, semiquantitative RT-PCR revealed PmMAP2Kip1 is widely distributed in most examined tissues except nerve, and high expressed in ovary, hemocyte, intestines and hepatopancreas. Meanwhile, PmMAP2k1ip1 is expressed ubiquitously during larval and sex gland development, and keep a high level at the initial development stage. Quantitative real time RT-PCR revealed PmMAP2K1ip1 were up-regulated by lipopolysaccharide and peptidoglycan (PGN) in haemocyte. These data reveal MAP2K1ip1 is a multifunction protein that involved development and immune response. It is benefit to characterize other MAPK signal genes and elucidate the molecular regulation mechanism of MAPK signaling in tiger shrimp.

  16. A genomic view of the sea urchin nervous system.

    PubMed

    Burke, R D; Angerer, L M; Elphick, M R; Humphrey, G W; Yaguchi, S; Kiyama, T; Liang, S; Mu, X; Agca, C; Klein, W H; Brandhorst, B P; Rowe, M; Wilson, K; Churcher, A M; Taylor, J S; Chen, N; Murray, G; Wang, D; Mellott, D; Olinski, R; Hallböök, F; Thorndyke, M C

    2006-12-01

    The sequencing of the Strongylocentrotus purpuratus genome provides a unique opportunity to investigate the function and evolution of neural genes. The neurobiology of sea urchins is of particular interest because they have a close phylogenetic relationship with chordates, yet a distinctive pentaradiate body plan and unusual neural organization. Orthologues of transcription factors that regulate neurogenesis in other animals have been identified and several are expressed in neurogenic domains before gastrulation indicating that they may operate near the top of a conserved neural gene regulatory network. A family of genes encoding voltage-gated ion channels is present but, surprisingly, genes encoding gap junction proteins (connexins and pannexins) appear to be absent. Genes required for synapse formation and function have been identified and genes for synthesis and transport of neurotransmitters are present. There is a large family of G-protein-coupled receptors, including 874 rhodopsin-type receptors, 28 metabotropic glutamate-like receptors and a remarkably expanded group of 161 secretin receptor-like proteins. Absence of cannabinoid, lysophospholipid and melanocortin receptors indicates that this group may be unique to chordates. There are at least 37 putative G-protein-coupled peptide receptors and precursors for several neuropeptides and peptide hormones have been identified, including SALMFamides, NGFFFamide, a vasotocin-like peptide, glycoprotein hormones and insulin/insulin-like growth factors. Identification of a neurotrophin-like gene and Trk receptor in sea urchin indicates that this neural signaling system is not unique to chordates. Several hundred chemoreceptor genes have been predicted using several approaches, a number similar to that for other animals. Intriguingly, genes encoding homologues of rhodopsin, Pax6 and several other key mammalian retinal transcription factors are expressed in tube feet, suggesting tube feet function as photosensory

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

    PubMed

    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.

  18. Comparative Study of Regulatory Circuits in Two Sea Urchin Species Reveals Tight Control of Timing and High Conservation of Expression Dynamics.

    PubMed

    Gildor, Tsvia; Ben-Tabou de-Leon, Smadar

    2015-07-01

    Accurate temporal control of gene expression is essential for normal development and must be robust to natural genetic and environmental variation. Studying gene expression variation within and between related species can delineate the level of expression variability that development can tolerate. Here we exploit the comprehensive model of sea urchin gene regulatory networks and generate high-density expression profiles of key regulatory genes of the Mediterranean sea urchin, Paracentrotus lividus (Pl). The high resolution of our studies reveals highly reproducible gene initiation times that have lower variation than those of maximal mRNA levels between different individuals of the same species. This observation supports a threshold behavior of gene activation that is less sensitive to input concentrations. We then compare Mediterranean sea urchin gene expression profiles to those of its Pacific Ocean relative, Strongylocentrotus purpuratus (Sp). These species shared a common ancestor about 40 million years ago and show highly similar embryonic morphologies. Our comparative analyses of five regulatory circuits operating in different embryonic territories reveal a high conservation of the temporal order of gene activation but also some cases of divergence. A linear ratio of 1.3-fold between gene initiation times in Pl and Sp is partially explained by scaling of the developmental rates with temperature. Scaling the developmental rates according to the estimated Sp-Pl ratio and normalizing the expression levels reveals a striking conservation of relative dynamics of gene expression between the species. Overall, our findings demonstrate the ability of biological developmental systems to tightly control the timing of gene activation and relative dynamics and overcome expression noise induced by genetic variation and growth conditions.

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

    PubMed

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

    PubMed

    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 i