A comparative study of spatially clustered distribution of jumbo flying squid ( Dosidicus gigas) offshore Peru

NASA Astrophysics Data System (ADS)

Feng, Yongjiu; Cui, Li; Chen, Xinjun; Liu, Yu

2017-06-01

We examined spatially clustered distribution of jumbo flying squid ( Dosidicus gigas) in the offshore waters of Peru bounded by 78°-86°W and 8°-20°S under 0.5°×0.5° fishing grid. The study is based on the catch-per-unit-effort (CPUE) and fishing effort from Chinese mainland squid jigging fleet in 2003-2004 and 2006-2013. The data for all years as well as the eight years (excluding El Niño events) were studied to examine the effect of climate variation on the spatial distribution of D. gigas. Five spatial clusters reflecting the spatial distribution were computed using K-means and Getis-Ord Gi* for a detailed comparative study. Our results showed that clusters identified by the two methods were quite different in terms of their spatial patterns, and K-means was not as accurate as Getis-Ord Gi*, as inferred from the agreement degree and receiver operating characteristic. There were more areas of hot and cold spots in years without the impact of El Niño, suggesting that such large-scale climate variations could reduce the clustering level of D. gigas. The catches also showed that warm El Niño conditions and high water temperature were less favorable for D. gigas offshore Peru. The results suggested that the use of K-means is preferable if the aim is to discover the spatial distribution of each sub-region (cluster) of the study area, while Getis-Ord Gi* is preferable if the aim is to identify statistically significant hot spots that may indicate the central fishing ground.

Examining spatiotemporal distribution and CPUE-environment relationships for the jumbo flying squid Dosidicus gigas offshore Peru based on spatial autoregressive model

NASA Astrophysics Data System (ADS)

Feng, Yongjiu; Chen, Xinjun; Liu, Yang

2017-09-01

The spatiotemporal distribution and relationship between nominal catch-per-unit-effort (CPUE) and environment for the jumbo flying squid (Dosidicus gigas) were examined in offshore Peruvian waters during 2009-2013. Three typical oceanographic factors affecting the squid habitat were investigated in this research, including sea surface temperature (SST), sea surface salinity (SSS) and sea surface height (SSH). We studied the CPUE-environment relationships for D. gigas using a spatially-lagged version of spatial autoregressive (SAR) model and a generalized additive model (GAM), with the latter for auxiliary and comparative purposes. The annual fishery centroids were distributed broadly in an area bounded by 79.5°-82.7°W and 11.9°-17.1°S, while the monthly fishery centroids were spatially close and lay in a smaller area bounded by 81.0°-81.2°W and 14.3°-15.4°S. Our results show that the preferred environmental ranges for D. gigas offshore Peru were 20.9°-21.9°C for SST, 35.16-35.32 for SSS and 27.2-31.5 cm for SSH in the areas bounded by 78°-80°W/82-84°W and 15°-18°S. Monthly spatial distributions during October to December were predicted using the calibrated GAM and SAR models and general similarities were found between the observed and predicted patterns for the nominal CPUE of D. gigas. The overall accuracies for the hotspots generated by the SAR model were much higher than those produced by the GAM model for all three months. Our results contribute to a better understanding of the spatiotemporal distributions of D. gigas offshore Peru, and offer a new SAR modeling method for advancing fishery science.

Fishery biology of jumbo flying squid Dosidicus gigas off Costa Rica Dome

NASA Astrophysics Data System (ADS)

Chen, Xinjun; Li, Jianghua; Liu, Bilin; Li, Gang; Lu, Huajie

2014-06-01

The jumbo flying squid ( Dosidicus gigas) population was surveyed with the help of Chinese squid jigging vessels off the Costa Rica Dome (4°-11°N, 90°-100°W) in 2009 and 2010. The daily catch of D. gigas in the two survey cruises ranged from 0 to 5.5 t and was mostly obtained from the areas bounded by 6°-9°N and 91°-94°W and by 6°30'-7°30'N and 96°-97°W. The sea surface temperature in the areas yielding the most catch ranged from 27.5 to 29°C. The sex ratio of the total catch was 3.75:1 (female: male). The mantle length of the squid ranged from 211 to 355 mm (male) and from 204 to 429 mm (female) with an average of 297.9 and 306.7 mm, respectively. In the relationship of the mantle length (mm) and body weight (g) of the squid, there was no significant difference between sexes. The female and male were at a similar maturity, and most individuals are maturing or have matured with a few females being spent. The size (mantle length) and age at the first sexual maturity were 297 mm and 195 d in females, and less than 211 mm and 130 d in males, respectively. Most of the sampled stomachs (70.6%) had no food remains. The major preys of the squids were fish, cephalopods and crustaceans, with the most abundant Myctophum orientale and D. gigas. The preys in more than 65% of the non-empty sampled stomachs evidenced the cannibalism of D. gigas. The results improved current understanding of the fishery biology of D. gigas off the Costa Rica Dome, which may facilitate the assessment and management of relative fishery resources.

Digestion of Ceramide 2-Aminoethylphosphonate, a Sphingolipid from the Jumbo Flying Squid Dosidicus gigas, in Mice.

PubMed

Tomonaga, Nami; Manabe, Yuki; Sugawara, Tatsuya

2017-04-01

Ceramide 2-aminoethylphosphonate (CAEP), a sphingophosphonolipid containing a carbon-phosphorus bond, is frequently found in marine organisms and has a unique triene type of sphingoid base in its structure. CAEP has not been evaluated as a food ingredient, although it is generally contained in Mollusca organisms such as squids and shellfish, which are consumed worldwide. In this study, we aimed to elucidate the effects of CAEP as a food component by evaluating the digestion of CAEP extracted from the skin of the jumbo flying squid Dosidicus gigas. Our results revealed that dietary CAEP was digested to free sphingoid bases via ceramides by the mouse small intestinal mucosa. At pH 7.2, CAEP was hydrolyzed more rapidly than the major mammalian sphingolipid sphingomyelin; however, the hydrolysis of CAEP was similar to that of sphingomyelin at pH 9.0. Thus, the digestion of CAEP may be catalyzed by alkaline spingomyelinase and other enzymes. Our findings provide important insights into the digestion of the dietary sphingophosphonolipid CAEP in marine foods.

Salting-in effect on muscle protein extracted from giant squid (Dosidicus gigas).

PubMed

Zhang, Rui; Zhou, Ru; Pan, Weichun; Lin, Weiwei; Zhang, Xiuzhen; Li, Mengya; Li, Jianrong; Niu, Fuge; Li, Ang

2017-01-15

The salting-in effect on muscle protein is well-known in food science but hard to explain using conventional theories. Myofibrillar protein extracted from the giant squid (Dosidicus gigas) was selected as a model muscle protein to study this mechanism in KCl solutions. Changes in the secondary structures of myofibrillar protein molecules caused by concentrated salts, particularly in the paramyosin molecule conformation, have been reported. Zeta-potential determinations showed that these secondary structures have modified protein molecule surfaces. The zeta-potential of the myofibrillar protein molecules fell from -7.24±0.82 to -9.99±1.65mV with increasing salt concentration from 0.1 to 0.5M. The corresponding second virial coefficient increased from -85.43±3.8×10(-7) to -3.45±1.3×10(-7) molmLg(-2). The extended law of corresponding states suggests that reduced attractive interactions increase the protein solubility. Solubility measurements in alternating KCl concentrations showed that the conformational change was reversible. Copyright © 2016 Elsevier Ltd. All rights reserved.

Partial characterization of an effluent produced by cooking of Jumbo squid (Dosidicus gigas) mantle muscle.

PubMed

Rosas-Romero, Zaidy G; Ramirez-Suarez, Juan C; Pacheco-Aguilar, Ramón; Lugo-Sánchez, Maria E; Carvallo-Ruiz, Gisela; García-Sánchez, Guillermina

2010-01-01

Jumbo squid (Dosidicus gigas) mantle muscle was cooked simulating industrial procedures (95 degrees C x 25 min, 1.2:5 muscle:water ratio). The effluent produced was analyzed for chemical and biochemical oxygen demands (COD and BOD(5), respectively), proximate analysis, flavor-related compounds (free amino acids, nucleotides and carbohydrates) and SDS-PAGE. The COD and BOD(5) exhibited variation among samplings (N=3) (27.4-118.5 g O(2)/L for COD and 11.3-26.7 g O(2)/L for BOD(5)). The effluent consisted of 1% total solids, 75% of which represented crude protein. Sixty percent of the total free amino acid content, which imparts flavor in squid species, corresponded to glutamic acid, serine, glycine, arginine, alanine, leucine and lysine. The nucleotide concentration followed this order, Hx>ADP>AMP>ATP>IMP>HxR. The variation observed in the present work was probably due to physiological maturity differences among the squid specimens (i.e., juvenile versus mature). Solids present in squid cooking effluent could be recovered and potentially used as flavor ingredients in squid-analog production by the food industry.

Investigation of jumbo squid (Dosidicus gigas) skin gelatin peptides for their in vitro antioxidant effects.

PubMed

Mendis, Eresha; Rajapakse, Niranjan; Byun, Hee-Guk; Kim, Se-Kwon

2005-09-09

Peptides derived from tryptic hydrolysate of jumbo squid (Dosidicus gigas) skin gelatin were assessed for their antioxidant properties in different in vitro assay systems. The hydrolysate itself exhibited a strong lipid peroxidation inhibition and it was much higher than that of natural antioxidant, alpha-tocopherol. In addition, it could scavenge highly active free radicals in oxidative systems, in the order of hydroxyl and carbon-centered radicals. Two representative peptides with comparatively higher antioxidant potency were purified and characterized as Phe-Asp-Ser-Gly-Pro-Ala-Gly-Val-Leu (880.18 Da) and Asn-Gly-Pro-Leu-Gln-Ala-Gly-Gln-Pro-Gly-Glu-Arg (1241.59 Da). Furthermore, viability of radical-mediated oxidation-induced human lung fibroblasts was enhanced following the treatment of two peptides. However it did not exhibit substantial ion chelation, and we presumed that the observed radical scavenging potency of these peptides play a vital role for their strong antioxidant activity. Based on our results we suggest that hydrophobic amino acids present in peptide sequences contributed greatly for observed antioxidant activities.

Behavioral ecology of jumbo squid (Dosidicus gigas) in relation to oxygen minimum zones

NASA Astrophysics Data System (ADS)

Stewart, Julia S.; Field, John C.; Markaida, Unai; Gilly, William F.

2013-10-01

Habitat utilization, behavior and food habits of the jumbo or Humboldt squid, Dosidicus gigas, were compared between an area recently inhabited in the northern California Current System (CCS) and a historically established area of residence in the Gulf of California (GOC). Low dissolved oxygen concentrations at midwater depths define the oxygen minimum zone (OMZ), an important environmental feature in both areas. We analyzed vertical diving behavior and diet of D. gigas and hydrographic properties of the water column to ascertain the extent to which squid utilized the OMZ in the two areas. The upper boundary of the OMZ has been shoaling in recent decades in the CCS, and this phenomenon has been proposed to vertically compress the pelagic environment inhabited by aerobic predators. A shoaling OMZ will also bring mesopelagic communities into a depth range with more illumination during daytime, making these organisms more vulnerable to predation by visual predators (i.e. jumbo squid). Because the OMZ in the GOC is considerably shallower than in the CCS, our study provides insight into the behavioral plasticity of jumbo squid and how they may respond to a shoaling OMZ in the CCS. We propose that shoaling OMZs are likely to be favorable to jumbo squid and could be a key indirect factor behind the recent range expansion of this highly migratory predator.

Comprehensive Model of Jumbo Squid Dosidicus gigas Trophic Ecology in the Northern Humboldt Current System

PubMed Central

Alegre, Ana; Ménard, Frédéric; Tafur, Ricardo; Espinoza, Pepe; Argüelles, Juan; Maehara, Víctor; Flores, Oswaldo; Simier, Monique; Bertrand, Arnaud

2014-01-01

The jumbo squid Dosidicus gigas plays an important role in marine food webs both as predator and prey. We investigated the ontogenetic and spatiotemporal variability of the diet composition of jumbo squid in the northern Humboldt Current system. For that purpose we applied several statistical methods to an extensive dataset of 3,618 jumbo squid non empty stomachs collected off Peru from 2004 to 2011. A total of 55 prey taxa was identified that we aggregated into eleven groups. Our results evidenced a large variability in prey composition as already observed in other systems. However, our data do not support the hypothesis that jumbo squids select the most abundant or energetic taxon in a prey assemblage, neglecting the other available prey. Indeed, multinomial model predictions showed that stomach fullness increased with the number of prey taxa, while most stomachs with low contents contained one or two prey taxa only. Our results therefore question the common hypothesis that predators seek locally dense aggregations of monospecific prey. In addition D. gigas consumes very few anchovy Engraulis ringens in Peru, whereas a tremendous biomass of anchovy is potentially available. It seems that D. gigas cannot reach the oxygen unsaturated waters very close to the coast, where the bulk of anchovy occurs. Indeed, even if jumbo squid can forage in hypoxic deep waters during the day, surface normoxic waters are then required to recover its maintenance respiration (or energy?). Oxygen concentration could thus limit the co-occurrence of both species and then preclude predator-prey interactions. Finally we propose a conceptual model illustrating the opportunistic foraging behaviour of jumbo squid impacted by ontogenetic migration and potentially constrained by oxygen saturation in surface waters. PMID:24465788

Locomotion and behavior of Humboldt squid, Dosidicus gigas, in relation to natural hypoxia in the Gulf of California, Mexico.

PubMed

Gilly, William F; Zeidberg, Louis D; Booth, J Ashley T; Stewart, Julia S; Marshall, Greg; Abernathy, Kyler; Bell, Lauren E

2012-09-15

We studied the locomotion and behavior of Dosidicus gigas using pop-up archival transmitting (PAT) tags to record environmental parameters (depth, temperature and light) and an animal-borne video package (AVP) to log these parameters plus acceleration along three axes and record forward-directed video under natural lighting. A basic cycle of locomotor behavior in D. gigas involves an active climb of a few meters followed by a passive (with respect to jetting) downward glide carried out in a fins-first direction. Temporal summation of such climb-and-glide events underlies a rich assortment of vertical movements that can reach vertical velocities of 3 m s(-1). In contrast to such rapid movements, D. gigas spends more than 80% of total time gliding at a vertical velocity of essentially zero (53% at 0±0.05 m s(-1)) or sinking very slowly (28% at -0.05 to -0.15 m s(-1)). The vertical distribution of squid was compared with physical features of the local water column (temperature, oxygen and light). Oxygen concentrations of ≤20 μmol kg(-1), characteristic of the midwater oxygen minimum zone (OMZ), can influence the daytime depth of squid, but this depends on location and season, and squid can 'decouple' from this environmental feature. Light is also an important factor in determining daytime depth, and temperature can limit nighttime depth. Vertical velocities were compared over specific depth ranges characterized by large differences in dissolved oxygen. Velocities were generally reduced under OMZ conditions, with faster jetting being most strongly affected. These data are discussed in terms of increased efficiency of climb-and-glide swimming and the potential for foraging at hypoxic depths.

Comprehensive model of Jumbo squid Dosidicus gigas trophic ecology in the Northern Humboldt current system.

PubMed

Alegre, Ana; Ménard, Frédéric; Tafur, Ricardo; Espinoza, Pepe; Argüelles, Juan; Maehara, Víctor; Flores, Oswaldo; Simier, Monique; Bertrand, Arnaud

2014-01-01

The jumbo squid Dosidicus gigas plays an important role in marine food webs both as predator and prey. We investigated the ontogenetic and spatiotemporal variability of the diet composition of jumbo squid in the northern Humboldt Current system. For that purpose we applied several statistical methods to an extensive dataset of 3,618 jumbo squid non empty stomachs collected off Peru from 2004 to 2011. A total of 55 prey taxa was identified that we aggregated into eleven groups. Our results evidenced a large variability in prey composition as already observed in other systems. However, our data do not support the hypothesis that jumbo squids select the most abundant or energetic taxon in a prey assemblage, neglecting the other available prey. Indeed, multinomial model predictions showed that stomach fullness increased with the number of prey taxa, while most stomachs with low contents contained one or two prey taxa only. Our results therefore question the common hypothesis that predators seek locally dense aggregations of monospecific prey. In addition D. gigas consumes very few anchovy Engraulis ringens in Peru, whereas a tremendous biomass of anchovy is potentially available. It seems that D. gigas cannot reach the oxygen unsaturated waters very close to the coast, where the bulk of anchovy occurs. Indeed, even if jumbo squid can forage in hypoxic deep waters during the day, surface normoxic waters are then required to recover its maintenance respiration (or energy?). Oxygen concentration could thus limit the co-occurrence of both species and then preclude predator-prey interactions. Finally we propose a conceptual model illustrating the opportunistic foraging behaviour of jumbo squid impacted by ontogenetic migration and potentially constrained by oxygen saturation in surface waters.

Chromogenic behaviors of the Humboldt squid (Dosidicus gigas) studied in situ with an animal-borne video package.

PubMed

Rosen, Hannah; Gilly, William; Bell, Lauren; Abernathy, Kyler; Marshall, Greg

2015-01-15

Dosidicus gigas (Humboldt or jumbo flying squid) is an economically and ecologically influential species, yet little is known about its natural behaviors because of difficulties in studying this active predator in its oceanic environment. By using an animal-borne video package, National Geographic's Crittercam, we were able to observe natural behaviors in free-swimming D. gigas in the Gulf of California with a focus on color-generating (chromogenic) behaviors. We documented two dynamic displays without artificial lighting at depths of up to 70 m. One dynamic pattern, termed 'flashing' is characterized by a global oscillation (2-4 Hz) of body color between white and red. Flashing was almost always observed when other squid were visible in the video frame, and this behavior presumably represents intraspecific signaling. Amplitude and frequency of flashing can be modulated, and the phase relationship with another squid can also be rapidly altered. Another dynamic display termed 'flickering' was observed whenever flashing was not occurring. This behavior is characterized by irregular wave-like activity in neighboring patches of chromatophores, and the resulting patterns mimic reflections of down-welled light in the water column, suggesting that this behavior may provide a dynamic type of camouflage. Rapid and global pauses in flickering, often before a flashing episode, indicate that flickering is under inhibitory neural control. Although flashing and flickering have not been described in other squid, functional similarities are evident with other species. © 2015. Published by The Company of Biologists Ltd.

[A study on feeding ecology and migration patterns of Dosidicus gigas off Peru using stable isotope analysis].

PubMed

Gong, Yi; Chen, Xin-jun; Li, Yun-kai; Han, Meng-jie

2015-09-01

As a pelagic cephalopod and one of the main target species of Chinese distant water fishery, jumbo squids (Dosidicus gigas) play a major role in the marine ecosystems of the eastern Pacific. Understanding the feeding ecology and migration patterns of jumbo squids is of importance for better utilizing the resources. The isotopic signatures of gladius, have been proved to be a powerful tool to reveal high resolution and ontogenic variations in individual foraging strategies of squids; which is an archival tissue with no elemental turnover after formation. In this study, the growth equation of gladius proostracum was established based on the age information determined by statolith. Gladius was cut successionally by the growth curve of gladius proostracum, the stable isotopic values of the gladius profiles were determined, and the feeding ecology and migration patterns of jumbo squids during its growth process were investigated. Results showed that the jumbo squids began to migrate after 180 days of postnatal, and their trophic levels tended to decrease throughout the life span. These results demonstrated the feasibility of using continuous sampling hard tissue to study the feeding ecology and habitat transfer of jumbo squids.

ESR studies on the thermal decomposition of trimethylamine oxide to formaldehyde and dimethylamine in jumbo squid (Dosidicus gigas) extract.

PubMed

Zhu, Junli; Jia, Jia; Li, Xuepeng; Dong, Liangliang; Li, Jianrong

2013-12-15

The effects of ferrous iron, heating temperature and different additives on the decomposition of trimethylamine oxide (TMAO) to formaldehyde (FA) and dimethylamine (DMA) and generation of free radicals in jumbo squid (Dosidicus gigas) extract during heating were evaluated by electron spin resonance (ESR). The thermal decomposition of TMAO to TMA, DMA and FA and free radical signals was observed in squid extract, whereas no DMA, FA and free radical signals were detected in cod extract or in aqueous TMAO solution in vitro at high temperatures. Significant increase in levels of DMA, FA and radicals intensity were observed in squid extract and TMAO solution in the presence of ferrous iron with increasing temperature. Hydrogen peroxide stimulated the production of DMA, FA and ESR signals in squid extract, while citric acid, trisodium citrate, calcium chloride, tea polyphenols and resveratrol had the opposite effect. Similar ESR spectra of six peaks regarded as amminium radical were detected in the squid extract and TMAO-iron(II) solution, suggesting that the amminium radical was involved in the decomposition of TMAO. Copyright © 2013 Elsevier Ltd. All rights reserved.

Revealing the potential of squid chitosan-based structures for biomedical applications.

PubMed

Reys, L L; Silva, S S; Oliveira, J M; Caridade, S G; Mano, J F; Silva, T H; Reis, R L

2013-08-01

In recent years, much attention has been given to different marine organisms, namely as potential sources of valuable materials with a vast range of properties and characteristics. In this work, β-chitin was isolated from the endoskeleton of the giant squid Dosidicus gigas and further deacetylated to produce chitosan. Then, the squid chitosan was processed into membranes and scaffolds using solvent casting and freeze-drying, respectively, to assess their potential biomedical application. The developed membranes have shown to be stiffer and less hydrophobic than those obtained with commercial chitosan. On the other hand, the morphological characterization of the developed scaffolds, by SEM and micro-computed tomography, revealed that the matrices were formed with a lamellar structure. The findings also indicated that the treatment with ethanol prior to neutralization with sodium hydroxide caused the formation of larger pores and loss of some lamellar features. The in vitro cell culture study has shown that all chitosan scaffolds exhibited a non-cytotoxic effect over the mouse fibroblast-like cell line, L929 cells. Thus, chitosan produced from the endoskeletons of the giant squid Dosidicus gigas has proven to be a valuable alternative to existing commercial materials when considering its use as biomaterial.

Trace element concentrations in the top predator jumbo squid (Dosidicus gigas) from the Gulf of California.

PubMed

Raimundo, Joana; Vale, Carlos; Rosa, Rui

2014-04-01

Jumbo (or Humboldt) squid, Dosidicus gigas, is a large jet-propelled top oceanic predator off the Eastern Pacific. The present study reports, for the first time, concentrations of V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Cd and Pb in gills, mantle and digestive gland of this powerful pelagic squid in the Gulf of California. Zinc and Cu were the most abundant elements. All elements, with the exception of As, were largely stored in digestive gland; particularly Cd that reached concentrations between 57 and 509 µg g(-1). Significant relationships between tissues were found for Co (digestive gland-gills), As (gills-mantle) and Cd (digestive gland-mantle). Proportionality of Cd concentrations between mantle and digestive gland suggested that detoxification capacity by digestive gland was insufficient to avoid the transfer of this element to mantle and other tissues. Nonetheless, Cd concentrations in the mantle were always below the regulatory limit and, therefore lack of constraints for human consumption. On the basis of the fishery landings, one may estimate that up to 1t of Cd can be annually removed by jumbo squid fisheries. Copyright © 2014 Elsevier Inc. All rights reserved.

Alkali- or acid-induced changes in structure, moisture absorption ability and deacetylating reaction of β-chitin extracted from jumbo squid (Dosidicus gigas) pens.

PubMed

Jung, Jooyeoun; Zhao, Yanyun

2014-01-01

Alkali- or acid-induced structural modifications in β-chitin from squid (Dosidicus gigas, d'Orbigny, 1835) pens and their moisture absorption ability (MAA) and deacetylating reaction were investigated and compared with α-chitin from shrimp shells. β-Chitin was converted into the α-form after 3h in 40% NaOH or 1-3 h in 40% HCl solution, and α-chitin obtained from NaOH treatment had higher MAA than had native α-chitin, due to polymorphic destructions. In contrast, induced α-chitin from acid treatment of β-chitin had few polymorphic modifications, showing no significant change (P>0.05) in MAA. β-Chitin was more susceptible to alkali deacetylation than was α-chitin, and required a lower concentration of NaOH and shorter reaction time. These results demonstrate that alkali- or acid-treated β-chitin retained high susceptibility toward solvents, which in turn resulted in good biological activity of β-chitosan for use as a natural antioxidant and antimicrobial substance or application as edible coatings and films for various food applications. Published by Elsevier Ltd.

Purification and characterization of trimethylamine-N-oxide demethylase from jumbo squid (Dosidicus gigas).

PubMed

Fu, Xue-Yan; Xue, Chang-Hu; Miao, Ben-Chun; Liang, Jun-Ni; Li, Zhao-Jie; Cui, Feng-Xia

2006-02-08

Trimethylamine-N-oxide demethylase (TMAOase) was purified from Jumbo squid (Dosidicus gigas) and characterized in detail herein. The TMAOase was extracted from squid with 20 mM Tris-acetate buffer (pH 7.0) containing 1.0 M NaCl, followed by acid treatment and heat treatment. Then it was purified by deithylaminoethyl-cellulose and Sephacryl S-300 chromatography, subsequently resulting in an 839-fold purification. The molecular mass of the TMAOase was defined to be 17.5 kDa. The optimum pH of the purified TMAOase was 7.0, and its optimum temperature was confirmed to be 55 degrees C. The TMAOase was stable to heat treatment up to 50 degrees C and stable at pH 7.0-9.0. Reducing agents such as DTT, Na2SO3, and NADH were effective at activating TMAOase, and ethylenediaminetetraacetic acid, as well as Mg2+ and Ca2+, could also enhance the activity of TMAOase remarkably, whereas the TMAOase could be significantly inhibited by tea polyphenol, phytic acid and acetic acid. In addition, the TMAOase converted TMAO to dimethylamine and formaldehyde stoichiometrically with a K(m) of 26.2 mM.

Rapid method for controlling the correct labeling of products containing common octopus (Octopus vulgaris) and main substitute species (Eledone cirrhosa and Dosidicus gigas) by fast real-time PCR.

PubMed

Espiñeira, Montserrat; Vieites, Juan M

2012-12-15

The TaqMan real-time PCR has the highest potential for automation, therefore representing the currently most suitable method for screening, allowing the detection of fraudulent or unintentional mislabeling of species. This work describes the development of a real-time polymerase chain reaction (RT-PCR) system for the detection and identification of common octopus (Octopus vulgaris) and main substitute species (Eledone cirrhosa and Dosidicus gigas). This technique is notable for the combination of simplicity, speed, sensitivity and specificity in an homogeneous assay. The method can be applied to all kinds of products; fresh, frozen and processed, including those undergoing intensive processes of transformation. This methodology was validated to check how the degree of food processing affects the method and the detection of each species. Moreover, it was applied to 34 commercial samples to evaluate the labeling of products made from them. The methodology herein developed is useful to check the fulfillment of labeling regulations for seafood products and to verify traceability in commercial trade and for fisheries control. Copyright © 2012 Elsevier Ltd. All rights reserved.

Jumbo squid (Dosidicus gigas) mantle collagen: extraction, characterization, and potential application in the preparation of chitosan-collagen biofilms.

PubMed

Uriarte-Montoya, Mario Hiram; Arias-Moscoso, Joe Luis; Plascencia-Jatomea, Maribel; Santacruz-Ortega, Hisila; Rouzaud-Sández, Ofelia; Cardenas-Lopez, Jose Luis; Marquez-Rios, Enrique; Ezquerra-Brauer, Josafat Marina

2010-06-01

Collagen-based biomaterials have been widely used due to its binding capabilities. However the properties and potential use of new collagen sources are still under investigation. Fish by-products are an excellent source of collagen. Thus, acid-soluble collagen (ASC) was extracted, and biochemical and physicochemically characterized from one under-utilized specie, jumbo squid (Dosidicus gigas). In addition, commercial chitosan (95-50%)-ASC (5-50%) blend films were successfully prepared by casting, and characterized by infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The molecular masses of the ASC subunits were about 190kDa, 110kDa, and 97kDa, the content of proline and hydroxyproline was 10.9% and 2.8%, respectively. The FT-IR and nuclear magnetic resonance spectra ((1)H NMR) confirmed collagen peptidic crosslinks, and one endothermic peak was found at 119 degrees C. The FT-IR spectrum showed that chitosan and ASC remain linked into the films mainly due to hydrogen bonding. The 85:15 (chitosan:ASC) ratio was selected for its thermal and mechanical analyses. The thermograms of this film indicated the presence of two peaks, one at 87-98 degrees C and the other at 142-182 degrees C. The chitosan:ASC blend produced a transparent and brittle film, with high percentage of elongation at break, and low tensile strength in comparison to chitosan films. D. gigas mantle might be useful as a new source of plasticizer agent in the preparation of biofilms in composites with chitosan. Copyright 2010 Elsevier Ltd. All rights reserved.

Paralarvae of the complex Sthenoteuthis oualaniensis - Dosidicus gigas (Cephalopoda: Ommastrephidae) in the northern limit of the shallow oxygen minimum zone of the Eastern Tropical Pacific Ocean.

NASA Astrophysics Data System (ADS)

Sanchez Velasco, L.; Ruvalcaba-Aroche, E. D.; Beier, E.; Godinez, V. M.; Barton, E. D.; Diaz-Viloria, N.; Pacheco, M.

2016-02-01

The three-dimensional distribution of the paralarvae of the complex Sthenoteuthis oualaniensis - Dosidicus gigas (Cephalopoda: Ommastrephidae) was analyzed in the northern limit of the shallow oxygen minimum zone in the Eastern Tropical Pacific (April, 2012). The hypoxic water ( 1 mL/L) rises from 100 m depth in the entrance of the Gulf of California to 20 m depth off Cabo Corrientes. Most of the paralarvae of this complex, dominated by D. gigas, were concentrated in the Gulf entrance, between the thermocline ( 20 to 50 m depth) and the sea surface, in the warmest (> 19oC) and oxygenated (> 4 mL/L) layer. The highest abundance of paralarvae was detected in an anticyclonic eddy ( 120 km diameter and > 500 m deep), which contained lower salinity water (< 35 g/kg), consistent with formation in the California Current. Lower paralarvae abundance was recorded further south off Cabo Corrientes, where hypoxic layers were elevated as water shoaled near shore. No paralarvae were found in the north of the study area beyond the strong salinity front ( 34.8 - 35.4 g/kg) that bounded the anticyclone. These results showed an affinity of the paralarvae for lower salinity, oxygenated water, illustrated by the influence of the mesoescale anticyclonic eddy and the salinity front in their distribution. Based on this study, it can be hypothesized that the expansion of the depth range of hypoxic water observed in the Eastern Tropical Pacific is vertically restricting the paralarvae habitat and likely causing a northward expansion of its range.

ELECTROPHORETIC AND IMMUNOLOGICAL STUDIES OF SQUID AXOPLASM PROTEINS.

PubMed

HUNEEUS-COX, F

1964-03-06

By disc electrophoresis of the axoplasm of Dosidicus gigas, 14 protein bands have been resolved. Anti-bodies to the intra-axonal proteins and to squid blood proteins were produced in rabbits. By Ouchterlony's technique, six antigenic components can be demonstrated in axoplasm; the combined use of disc electrophoresis and immune diflusion in agar resolves seven antigenic components in axoplasm; none of these components is detectable in squid blood.

Age, maturation, and population structure of the Humboldt squid Dosidicus gigas off the Peruvian Exclusive Economic Zones

NASA Astrophysics Data System (ADS)

Liu, Bilin; Chen, Xinjun; Chen, Yong; Tian, Siquan; Li, Jianhua; Fang, Zhou; Yang, Mingxia

2013-01-01

Age, maturation and population structure of the Humboldt squid Dosidicus gigas were studied based on random sampling of the Chinese jigging fishery off the Peruvian Exclusive Economic Zones (EEZ) during 2008-2010. Estimated ages ranged from 144 to 633 days, confirming that the squid is a short-lived species with longevity no longer than 2 years. Occurrence of mature females and hatching in each month indicated that Humboldt squid spawned year-round. Back-calculated hatching dates for the samples were from January 22nd, 2008 to April 22nd, 2010 with a peak between January and March. Two size-based and two hatching date-based populations could be defined from mantle length (ML) at maturity and back-calculated hatching dates, respectively. Females matured at a larger size than males, and there was a significant difference in ML at maturity between the two hatching groups ( P <0.05). The waters adjacent to 11°S off the Peruvian EEZ may be a potential spawning ground. This study shows the complexity of the population structure and large variability in key life history parameters in the Humboldt squid off the Peruvian EEZ, which should be considered in the assessment and management of this important resource.

Characteristics of deacetylation and depolymerization of β-chitin from jumbo squid (Dosidicus gigas) pens.

PubMed

Jung, Jooyeoun; Zhao, Yanyun

2011-09-27

This study evaluated the deacetylation characteristics of β-chitin from jumbo squid (Dosidicus gigas) pens by using strongly alkaline solutions of NaOH or KOH. Taguchi design was employed to investigate the effect of reagent concentration, temperature, time, and treatment step on molecular mass (MM) and degree of deacetylation (DDA) of the chitosan obtained. The optimal treatment conditions for achieving high MM and DDA of chitosan were identified as: 40% NaOH at 90°C for 6h with three separate steps (2h+2h+2h) or 50% NaOH at 90°C for 6h with one step, or 50% KOH at 90°C for 4h with three steps (1h+1h+2h) or 6h with one step. The most important factor affecting DDA and MM was temperature and time, respectively. The chitosan obtained was then further depolymerized by cellulase or lysozyme with cellulase giving a higher degradation ratio, lower relative viscosity, and a larger amount of reducing-end formations than that of lysozyme due to its higher susceptibility. This study demonstrated that jumbo squid pens are a good source of materials to produce β-chitosan with high DDA and a wide range of MM for various potential applications. Copyright © 2011 Elsevier Ltd. All rights reserved.

Paralarvae of the complex Sthenoteuthis oualaniensis-Dosidicus gigas (Cephalopoda: Ommastrephidae) in the northern limit of the shallow oxygen minimum zone of the Eastern Tropical Pacific Ocean (April 2012)

NASA Astrophysics Data System (ADS)

Sánchez-Velasco, Laura; Ruvalcaba-Aroche, Erick D.; Beier, Emilio; Godínez, Victor M.; Barton, Eric D.; Díaz-Viloria, Noe; Pacheco, María. R.

2016-03-01

The three-dimensional distribution of the paralarvae of the complex Sthenoteuthis oualaniensis-Dosidicus gigas (Cephalopoda: Ommastrephidae) was analyzed at the northern limit of the shallow oxygen minimum zone in the Eastern Tropical Pacific in April 2012. The upper limit of the oxygen minimum water (˜44 µmol/kg or 1 mL/L) rises from ˜100 m depth in the entrance of the Gulf of California to ˜20 m depth off Cabo Corrientes. Most of the paralarvae of this complex, dominated by D. gigas, were concentrated in the Gulf entrance, between the thermocline (˜20 to ˜50 m depth) and the sea surface, in the warmest (>19°C) oxygenated (>176 µmol/kg) layer. The highest abundance of paralarvae was detected in an anticyclonic eddy (˜120 km diameter and >500 m deep), which contained lower-salinity water (<35 g/kg), consistent with formation in the California Current. Lower paralarvae abundance was recorded further south off Cabo Corrientes, where hypoxic layers were elevated as water shoaled nearshore. Almost no paralarvae were found in the north of the study area beyond the strong salinity front (˜34.8-35.4 g/kg) that bounded the anticyclone. These results showed an affinity of the paralarvae for lower-salinity, oxygenated water, illustrated by the influence of the mesoscale anticyclonic eddy and the salinity front in their distribution. Based on this study, it can be concluded that the expansion of the depth range of hypoxic water observed in the Eastern Tropical Pacific may be increasing environmental stress on the paralarvae by vertically restricting their habitat, and so affecting their survival.

Potential use of stable isotope and fatty acid analyses for traceability of geographic origins of jumbo squid (Dosidicus gigas).

PubMed

Gong, Yi; Li, Yunkai; Chen, Xinjun; Chen, Ling

2018-04-15

Squid is an important seafood resource for Asian and European countries. With the continuous development of processed squid products, an effective traceability system has become increasingly prominent. Here, we attempt to trace the fishery products of the main target species, jumbo squid (Dosidicus gigas), by using biochemical tracers. Carbon and nitrogen isotope ratios (δ 13 C and δ 15 N values) and fatty acid profiles were identified in squid from three harvest locations in the eastern Pacific Ocean by isotope ratio mass spectrometry and gas chromatography/mass spectrometry, respectively. Comparative analysis was used to evaluate the geographic variations in tracers and to identify the suitable discriminatory variables among origins. Significant spatial variations were found in isotopic values and fatty acid profiles in squid muscle tissues, possibly because of different food availability and/or oceanographic conditions that each group experiences at a given location. The stepwise discriminant analysis indicated that δ 15 N, C16:1n7, C17:1n7, C18:2n6, C20:1 and C20:4n6 were effective variables at differentiating origin. Combined use of stable isotope ratios and fatty acid analyses could trace geographic origins of jumbo squid. This study provides an alternative approach for improving authenticity evaluation of commercial squid products. Copyright © 2018 John Wiley & Sons, Ltd.

Functional properties of protein from frozen mantle and fin of jumbo squid Dosidicus gigas in function of pH and ionic strength.

PubMed

Rocha-Estrada, J G; Córdova-Murueta, J H; García-Carreño, F L

2010-10-01

Functional properties of protein from mantle and fin of the jumbo squid Dosidicus gigas were explained based on microscopic muscle fiber and protein fractions profiles as observed in SDS-PAGE. Fin has higher content of connective tissue and complex fiber arrangement, and we observed higher hardness of fin gels as expected. Myosin heavy chain (MHC) was found in sarcoplasmic, myofibril and soluble-in-alkali fractions of mantle and only in sarcoplasmic and soluble-in-alkali fractions of fin. An additive effect of salt concentration and pH affected the solubility and foaming properties. Fin and mantle proteins yielded similar results in solubility tests, but significant differences occurred for specific pH and concentrations of salt. Foaming capacity was proportional to solubility; foam stability was also affected by pH and salt concentration. Hardness and fracture strength of fin gels were significantly higher than mantle gels; gels from proteins of both tissues reached the highest level in the folding test. Structural and molecular properties, such as MHC and paramyosin solubility, arrangement of muscle fibers and the content of connective tissue were useful to explain the differences observed in these protein properties. High-strength gels can be formed from squid mantle or fin muscle. Fin displayed similar or better properties than mantle in all tests.

New icing media for quality enhancement of chilled hake (Merluccius merluccius) using a jumbo squid (Dosidicus gigas) skin extract.

PubMed

Ezquerra-Brauer, Josafat Marina; Miranda, José M; Chan-Higuera, Jesús Enrique; Barros-Velázquez, Jorge; Aubourg, Santiago P

2017-08-01

An advanced strategy for chilled fish preservation, based on the inclusion in ice of an extract of jumbo squid (Dosidicus gigas) skin (JSS), is proposed. Aqueous solutions including acetic acid-ethanol extracts of JSS were tested at two different concentrations as icing media, with the effects on the quality evolution of chilled hake (Merluccius merluccius) being monitored. A significant inhibition (P < 0.05) of microbial activity (aerobes, psychrotrophs, Enterobacteriaceae, proteolytic bacteria; pH, trimethylamine) was obtained in hake corresponding to the icing batch including the highest JSS concentration. Additionally, fish specimens from such icing conditions showed an inhibitory effect (P < 0.05) on lipid hydrolysis development, while no effect (P > 0.05) was depicted for lipid oxidation. Sensory analysis (skin and mucus development; eyes; gills; texture; external odour; raw and cooked flesh odour; flesh taste) indicated a shelf life extension of chilled hake stored in ice including the highest JSS concentration. A profitable use of JSS, an industrial by-product during jumbo squid commercialisation, has been developed in the present work, which leads to a remarkable microbial inhibition and a significant shelf life extension of chilled hake. In agreement with previous research, ommochrome pigments (i.e. lipophilic-type compounds) would be considered responsible for this preservative effect. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Spatial and trophic preferences of jumbo squid Dosidicus gigas (D´Orbigny, 1835) in the central Gulf of California: ecological inferences using stable isotopes.

PubMed

Trasviña-Carrillo, L D; Hernández-Herrera, A; Torres-Rojas, Y E; Galván-Magaña, F; Sánchez-González, A; Aguíñiga-García, S

2018-04-26

The jumbo squid Dosidicus gigas is a fishery resource of considerable economic and ecological importance in the Mexican Pacific. Studies on its habitat preferences are needed to understand recent fluctuations in the species' abundance and availability. Stable isotope analysis allows us to infer ecological aspects such as spatial distribution and trophic preferences. We used an isotope ratio mass spectrometer, automated for carbonate analysis, and coupled to an elemental analyzer, to determine the isotopic composition of statoliths (δ 18 O and δ 13 C values) and beaks (δ 13 C and δ 15 N values) from 219 individuals caught over two fishing seasons (2007 and 2009) off the coast of Santa Rosalía, in the central Gulf of California. We used these isotopic ratios to assess variation in spatial and trophic preferences by sex, size, and fishing season. In the 2009 group, we observed significant differences in statolith δ 13 C values and beak δ 13 C and δ 15 N values between males and females. Between size groups, we observed significant differences in statolith δ 18 O and δ 13 C values in 2007 and in beak δ 13 C and δ 15 N values during both seasons. Both seasons were characterized by high overlap in δ 18 O and δ 13 C values between sexes and in 2009 between size groups. We observed low trophic overlap between sexes in 2009 and between size groups during both seasons. The isotopic ratios from statoliths and beaks indicate that D. gigas has changed its spatial and trophic preferences, a shift that is probably related to changes in the species diet. This intraspecific variation in preferences could be related to characteristics such as size, which may influence squid distribution preferences. This article is protected by copyright. All rights reserved.

Effect of pulsed ultrasound on the physicochemical characteristics and emulsifying properties of squid (Dosidicus gigas) mantle proteins.

PubMed

Higuera-Barraza, O A; Torres-Arreola, W; Ezquerra-Brauer, J M; Cinco-Moroyoqui, F J; Rodríguez Figueroa, J C; Marquez-Ríos, E

2017-09-01

Food technologists are always looking to improve the functional properties of proteins. In this sense, in last years ultrasound has been used to improve some functional properties. For this reason, and considering that jumbo squid is an important fishery in northwest Mexico, the purpose of this research was to determine the effect of pulsed ultrasound on the physicochemical characteristics and emulsifying properties of squid (Dosidicus gigas) mantle proteins. Pulsed ultrasound (20kHz, 20, and 40% amplitude) was applied for 30, 60, and 90s to a protein extract prepared from giant squid mantle causing an increase (p<0.05) in surface hydrophobicity (S o ) from 108.4±1.4 to 239.1±2.4 after application of pulsed ultrasound at 40% of amplitude for 90s. The electrophoretic profile and the total and reactive sulfhydryl contents were not affected (p⩾0.05) by the ultrasound treatment. The emulsifying ability of the protein solution was improved (p<0.05), whereas the Emulsifier Activity Index (EAI) varied from123.67±5.52m 2 /g for the control and increased up to 217.7±3.8m 2 /g after application of the ultrasound. The Stability Emulsifier Index (EEI) was improved at 40% of amplitude by 60 and 90s. The results suggested that pulsed ultrasound used as pretreatment induced conformational changes in giant squid proteins, which improved the interfacial association between protein-oil phases, thus contributing to the improvement of their emulsifient properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Postmortem biochemical behavior of giant squid (Dosidicus gigas) mantle muscle stored in ice and its relation with quality parameters.

PubMed

Márquez-Ríos, E; Morán-Palacio, E F; Lugo-Sánchez, M E; Ocano-Higuera, V M; Pacheco-Aguilar, R

2007-09-01

Several freshness and spoilage indicators were monitored to characterize the postmortem biochemistry of giant squid (Dosidicus gigas) mantle muscle. Squid samples were obtained directly from the sea and kept at 0 degrees C during a 15-d storage period. Data at zero time were obtained from cryogenically frozen samples at time of capture. The adenosine 5'-triphosphate (ATP) degradation followed a different pattern as compared with that from fish species. ATP was almost completely depleted at 24-h postcatch from 6.54 to <1 micromol/g, while at the same time Hx was the predominant catabolite with a concentration of 4 mumol/g, reaching 6.85 micromol/g at day 15. K-value data followed a logarithmic pattern with time instead of a linear one, with no change after day 3, thus reducing its suitability as a freshness index. The coefficient Hx/AMP seems to be an adequate alternative for this purpose due to its constant increment with time. The high NH4Cl content in mantle muscle (461.3 +/- 24.5 mg of NH4(+)/100 g) derived from its physiological importance for the species compromises the use of the distillation step of the TVB-N analysis commonly used as a spoilage index. This fact explains why the initially high value of TVB-N detected in mantle muscle (243.7 mg N/100 g) did not correlate with the initial low TMA-N content (1.5 +/- 0.1 mg/100 g of muscle). The results suggested that under the experimental conditions the shelf life of squid exceeds 15 d.

Metabolic physiology of the Humboldt squid, Dosidicus gigas: Implications for vertical migration in a pronounced oxygen minimum zone

NASA Astrophysics Data System (ADS)

Rosa, Rui; Seibel, Brad A.

2010-07-01

The Humboldt (or jumbo) squid, Dosidicus gigas, is an active predator endemic to the Eastern Pacific that undergoes diel vertical migrations into a pronounced oxygen minimum layer (OML). Here, we investigate the physiological mechanisms that facilitate these migrations and assess the associated costs and benefits. Exposure to hypoxic conditions equivalent to those found in the OML (∼10 μM O 2 at 10 °C) led to a significant reduction in the squid’s routine metabolic rate (RMR), from 8.9 to 1.6 μmol O 2 g -1 h -1 ( p < 0.05), and a concomitant increase in mantle muscle octopine levels (from 0.50 to 5.24 μmol g -1 tissue, p < 0.05). Enhanced glycolitic ATP production accounted for only 7.0% and 2.8% at 10 °C and 20 °C, respectively, of the energy deficit that resulted from the decline in aerobic respiration. The observed metabolic suppression presumably extends survival time in the OML by conserving the finite stores of fermentable substrate and avoiding the accumulation of the deleterious anaerobic end products in the tissues. RMR increased significantly with temperature ( p < 0.05), from 8.9 (at 10 °C) to 49.85 μmol O 2 g -1 h -1 (at 25 °C) which yielded a Q10 of 2.0 between 10 and 20 °C and 7.9 between 20 and 25 °C ( p < 0.05). These results suggest that 25 °C, although within the normal surface temperature range in the Gulf of California, is outside this species’ normal temperature range. By following the scattering layer into oxygen-enriched shallow water at night, D. gigas may repay any oxygen debt accumulated during the daytime. The dive to deeper water may minimize exposure to stressful surface temperatures when most prey have migrated to depth during the daytime. The physiological and ecological strategies demonstrated here may have facilitated the recent range expansion of this species into northern waters where expanding hypoxic zones prohibit competing top predators.

Sequential isotopic signature along gladius highlights contrasted individual foraging strategies of jumbo squid (Dosidicus gigas).

PubMed

Lorrain, Anne; Argüelles, Juan; Alegre, Ana; Bertrand, Arnaud; Munaron, Jean-Marie; Richard, Pierre; Cherel, Yves

2011-01-01

Cephalopods play a major role in marine ecosystems, but knowledge of their feeding ecology is limited. In particular, intra- and inter-individual variations in their use of resources has not been adequatly explored, although there is growing evidence that individual organisms can vary considerably in the way they use their habitats and resources. Using δ(13)C and δ(15)N values of serially sampled gladius (an archival tissue), we examined high resolution variations in the trophic niche of five large (>60 cm mantle length) jumbo squids (Dosidicus gigas) that were collected off the coast of Peru. We report the first evidence of large inter-individual differences in jumbo squid foraging strategies with no systematic increase of trophic level with size. Overall, gladius δ(13)C values indicated one or several migrations through the squid's lifetime (∼8-9 months), during which δ(15)N values also fluctuated (range: 1 to 5‰). One individual showed an unexpected terminal 4.6‰ δ(15)N decrease (more than one trophic level), thus indicating a shift from higher- to lower-trophic level prey at that time. The data illustrate the high diversity of prey types and foraging histories of this species at the individual level. The isotopic signature of gladii proved to be a powerful tool to depict high resolution and ontogenic variations in individual foraging strategies of squids, thus complementing traditional information offered by stomach content analysis and stable isotopes on metabolically active tissues. The observed differences in life history strategies highlight the high degree of plasticity of the jumbo squid and its high potential to adapt to environmental changes.

Food web and fish stock changes in central Chile: comparing the roles of jumbo squid (Dosidicus gigas) predation, the environment, and fisheries

NASA Astrophysics Data System (ADS)

Neira, Sergio; Arancibia, Hugo

2013-10-01

We analyzed recent food web and fish stock changes in the central Chile marine ecosystem, comparing the roles of jumbo squid (Dosidicus gigas) as predator, the environment, and fishing. To accomplish this we used food web modeling and the Ecopath with Ecosim software (EwE). The principal fish stocks have experienced wide decadal fluctuations in the past 30 years, including stock collapses of horse mackerel (Trachurus murphyi) and hake (Merluccius gayi), and there was a large influx of jumbo squid during the mid-2000s. We used two EwE models representing the food web off central Chile to test the hypothesis that predation by jumbo squid has been significant in explaining the dynamics of the main fishing resources and other species in the study area. Results indicate that predation by jumbo squid on fish stocks is lower than that of other predators (e.g. hake) and the fishery. Long-term fluctuations (1978-2004) in the biomass of the main fish stocks (as well as other components of the food web) seem to be related to fishing and to variation in primary production, rather than to predation by jumbo squid alone. Jumbo squid seems to play a role as predator rather than prey in the system, but its impacts are low when compared with the impacts of other predators and fishing. Therefore, we conclude that jumbo squid predation on its prey was not the primary force behind the collapse of important fish stocks off central Chile. Future efforts should be directed to better understanding factors that trigger sudden increases in jumbo squid abundance off central Chile, as well as modeling its trophic impacts.

Sequential Isotopic Signature Along Gladius Highlights Contrasted Individual Foraging Strategies of Jumbo Squid (Dosidicus gigas)

PubMed Central

Lorrain, Anne; Argüelles, Juan; Alegre, Ana; Bertrand, Arnaud; Munaron, Jean-Marie; Richard, Pierre; Cherel, Yves

2011-01-01

Background Cephalopods play a major role in marine ecosystems, but knowledge of their feeding ecology is limited. In particular, intra- and inter-individual variations in their use of resources has not been adequatly explored, although there is growing evidence that individual organisms can vary considerably in the way they use their habitats and resources. Methodology/Principal Findings Using δ13C and δ15N values of serially sampled gladius (an archival tissue), we examined high resolution variations in the trophic niche of five large (>60 cm mantle length) jumbo squids (Dosidicus gigas) that were collected off the coast of Peru. We report the first evidence of large inter-individual differences in jumbo squid foraging strategies with no systematic increase of trophic level with size. Overall, gladius δ13C values indicated one or several migrations through the squid's lifetime (∼8–9 months), during which δ15N values also fluctuated (range: 1 to 5‰). One individual showed an unexpected terminal 4.6‰ δ15N decrease (more than one trophic level), thus indicating a shift from higher- to lower-trophic level prey at that time. The data illustrate the high diversity of prey types and foraging histories of this species at the individual level. Conclusions/Significance The isotopic signature of gladii proved to be a powerful tool to depict high resolution and ontogenic variations in individual foraging strategies of squids, thus complementing traditional information offered by stomach content analysis and stable isotopes on metabolically active tissues. The observed differences in life history strategies highlight the high degree of plasticity of the jumbo squid and its high potential to adapt to environmental changes. PMID:21779391

Prolonged Decline of Jumbo Squid (Dosidicus gigas) Landings in the Gulf of California is Associated with Chronically low wind Stress and Decreased Chlorophyll a after El Niño 2009-2010

NASA Astrophysics Data System (ADS)

Robinson, C. J.; Gomez-Gutierrez, J.

2016-02-01

Dosidicus gigas (jumbo squid) is an ecologically relevant predator in the Gulf of California, Mexico, where it supports an economically valuable fishery. The commercial jumbo squid fishery in the Gulf declined steeply after an El Niño event in 2009-2010, and subsequent landings have remained at historically low levels in the relevant squid fishing centers (Guaymas, Sonora, and Santa Rosalia, Baja California Sur). In this paper, we examined wind speed and satellite chlorophyll a concentrations on the jumbo squid fishing grounds as factors that would be expected to be relevant to this prolonged period of low landings. Analysis from local weather stations, remote sensing and fishery data showed that low jumbo squid landings from 2010 to 2015 occurred during a period abnormally weak winter/spring winds and extremely low chlorophyll a concentrations off the East Guaymas Basin. Results indicate that the squid fishing area in the Guaymas region has been chronically impoverished during this period, and that this area may no longer be a productive habitat for jumbo squid. In response to this decreased productivity, size-at-maturity of jumbo squid showed a drastic decrease over the same period. Results are compared with the effect of El Niño 1997-1998 on the jumbo squid fishery and size-at-maturity of this species in the Gulf of California. The key difference between the recovery phases for El Niño 1997-1998 versus El Niño2009-2010 was the wind intensity as measured in the Guaymas fishing area.

Marine nekton off Oregon and the 1997 98 El Nino

NASA Astrophysics Data System (ADS)

Pearcy, W. G.

2002-09-01

Several species of migratory, warm-water, oceanic fishes invaded Oregon waters during the summer of 1997. Also, the jumbo squid ( Dosidicus gigas), common in the eastern tropical Pacific, was reported for the first time in 1997 and was caught in large numbers. The occurrence of these oceanic nekton was associated with inshore advection of anomalously warm water. During 1998, after arrival of the main El Niño signal, some warm-water coastal fishes appeared off Oregon. However, unlike observations off California, fewer species of warm-water coastal fishes were noted during the 1997-98 El Niño than during the 1982-83 El Niño.

A preliminary analysis of trace-elemental signatures in statoliths of different spawning cohorts for Dosidicus gigas off EEZ waters of Chile

NASA Astrophysics Data System (ADS)

Liu, Bilin; Chen, Xinjun; Fang, Zhou; Hu, Song; Song, Qian

2015-12-01

We applied solution-based ICP-MS method to quantify the trace-elemental signatures in statoliths of jumbo flying squid, Dosidius gigas, which were collected from the waters off northern and central Chile during the scientific surveys carried out by Chinese squid jigging vessels in 2007 and 2008. The age and spawning date of the squid were back-calculated based on daily increments in statoliths. Eight elemental ratios (Sr/Ca, Ba/Ca, Mg/Ca, Mn/Ca, Na/Ca, Fe/Ca, Cu/Ca and Zn/Ca) were analyzed. It was found that Sr is the second most abundant element next to Ca, followed by Na, Fe, Mg, Zn, Cu, Ba and Mn. There was no significant relationship between element/Ca and sea surface temperature (SST) and sea surface salinity (SSS), although weak negative or positive tendency was found. MANOVA analysis showed that multivariate elemental signatures did not differ among the cohorts spawned in spring, autumn and winter, and no significant difference was found between the northern and central sampling locations. Classification results showed that all individuals of each spawned cohorts were correctly classified. This study demonstrates that the elemental signatures in D. gigas statoliths are potentially a useful tool to improve our understanding of its population structure and habitat environment.

Myogenic activity and serotonergic inhibition in the chromatophore network of the squid Dosidicus gigas (family Ommastrephidae) and Doryteuthis opalescens (family Loliginidae).

PubMed

Rosen, Hannah E; Gilly, William F

2017-12-15

Seemingly chaotic waves of spontaneous chromatophore activity occur in the ommastrephid squid D osidicus gigas in the living state and immediately after surgical disruption of all known inputs from the central nervous system. Similar activity is apparent in the loliginid Doryteuthis opalescens , but only after chronic denervation of chromatophores for 5-7 days. Electrically stimulated, neurally driven activity in intact individuals of both species is blocked by tetrodotoxin (TTX), but TTX has no effect on spontaneous wave activity in either D. gigas or denervated D. opalescens Spontaneous TTX-resistant activity of this sort is therefore likely myogenic, and such activity is eliminated in both preparations by serotonin (5-HT), a known inhibitor of chromatophore activity. Immunohistochemical techniques reveal that individual axons containing L-glutamate or 5-HT (and possibly both in a minority of processes) are associated with radial muscle fibers of chromatophores in intact individuals of both species, although the area of contact between both types of axons and muscle fibers is much smaller in D. gigas Glutamatergic and serotonergic axons degenerate completely following denervation in D. opalescens Spontaneous waves of chromatophore activity in both species are thus associated with reduced (or no) serotonergic input in comparison to the situation in intact D. opalescens Such differences in the level of serotonergic inhibition are consistent with natural chromogenic behaviors in these species. Our findings also suggest that such activity might propagate via the branching distal ends of radial muscle fibers. © 2017. Published by The Company of Biologists Ltd.

Foraging ecology and movement patterns of jumbo squid (Dosidicus gigas) in the California Current System

NASA Astrophysics Data System (ADS)

Field, John C.; Elliger, Carl; Baltz, Ken; Gillespie, Graham E.; Gilly, William F.; Ruiz-Cooley, R. I.; Pearse, Devon; Stewart, Julia S.; Matsubu, William; Walker, William A.

2013-10-01

From 2002 to 2010, the jumbo squid (Dosidicus gigas) has been regularly encountered in large numbers throughout the California Current System (CCS). This species, usually found in subtropical waters, could affect coastal pelagic ecosystems and fisheries as both predator and prey. Neither the abundance of jumbo squid nor the optimal ocean conditions in which they flourish are well known. To understand better the potential impacts of this species on both commercial fisheries and on food-web structure we collected nearly 900 specimens from waters of the CCS, covering over 20° of latitude, over a range of depths and seasons. We used demographic information (size, sex, and maturity state) and analyzed stomach contents using morphological and molecular methods to best understand the foraging ecology of this species in different habitats of the CCS. Squid were found to consume a broad array of prey. Prey in offshore waters generally reflected the forage base reported in previous studies (mainly mesopelagic fishes and squids), whereas in more coastal waters (shelf, shelf break and slope habitats) squid foraged on a much broader mix that included substantial numbers of coastal pelagic fishes (Pacific herring and northern anchovy, as well as osmerids and salmonids in northern waters) and groundfish (Pacific hake, several species of rockfish and flatfish). We propose a seasonal movement pattern, based on size and maturity distributions along with qualitative patterns of presence or absence, and discuss the relevance of both the movement and distribution of jumbo squid over space and time. We find that jumbo squid are a generalist predator, which feeds primarily on small, pelagic or mesopelagic micronekton but also on larger fishes when they are available. We also conclude that interactions with and potential impacts on ecosystems likely vary over space and time, in response to both seasonal movement patterns and highly variable year-to-year abundance of the squid themselves.

Effect of specific antibodies on the excitability of internally perfused squid axons.

PubMed

Huneeus, F C; Fernandez, H L

1967-11-01

Giant axons from the squid Dosidicus gigas were internally perfused with rabbit antiaxoplasm antibodies and their effect upon the action potential and the membrane potential was studied. Necessary requirements for the antibodies to affect these parameters in a consistent manner were: (a) removal of the bulk of axoplasm from the perfused zone, accomplished by initially perfusing with a cysteine-rich (400 mM) solution, and (b) addition of small amounts of cysteine (30 mM) to the antibody-containing solution. When these experimental conditions were met, conduction block ensued generally within 3 hr of the first contact of the axon inner surface with the antibody Antineurofilament antibodies and nonspecific antibodies had no effect. External application of antiaxoplasm antibodies had no effect.

Cross-linking Chemistry of Squid Beak*

PubMed Central

Miserez, Ali; Rubin, Daniel; Waite, J. Herbert

2010-01-01

In stark contrast to most aggressive predators, Dosidicus gigas (jumbo squids) do not use minerals in their powerful mouthparts known as beaks. Their beaks instead consist of a highly sclerotized chitinous composite with incremental hydration from the tip to the base. We previously reported l-3,4-dihydroxyphenylalanine (dopa)-histidine (dopa-His) as an important covalent cross-link providing mechanical strengthening to the beak material. Here, we present a more complete characterization of the sclerotization chemistry and describe additional cross-links from D. gigas beak. All cross-links presented in this report share common building blocks, a family of di-, tri-, and tetra-histidine-catecholic adducts, that were separated by affinity chromatography and high performance liquid chromatography (HPLC) and identified by tandem mass spectroscopy and proton nuclear magnetic resonance (1H NMR). The data provide additional insights into the unusually high cross-link density found in mature beaks. Furthermore, we propose both a low molecular weight catechol, and peptidyl-dopa, to be sclerotization agents of squid beak. This appears to represent a new strategy for forming hard tissue in animals. The interplay between covalent cross-linking and dehydration on the graded properties of the beaks is discussed. PMID:20870720

Cross-linking chemistry of squid beak.

PubMed

Miserez, Ali; Rubin, Daniel; Waite, J Herbert

2010-12-03

In stark contrast to most aggressive predators, Dosidicus gigas (jumbo squids) do not use minerals in their powerful mouthparts known as beaks. Their beaks instead consist of a highly sclerotized chitinous composite with incremental hydration from the tip to the base. We previously reported l-3,4-dihydroxyphenylalanine (dopa)-histidine (dopa-His) as an important covalent cross-link providing mechanical strengthening to the beak material. Here, we present a more complete characterization of the sclerotization chemistry and describe additional cross-links from D. gigas beak. All cross-links presented in this report share common building blocks, a family of di-, tri-, and tetra-histidine-catecholic adducts, that were separated by affinity chromatography and high performance liquid chromatography (HPLC) and identified by tandem mass spectroscopy and proton nuclear magnetic resonance ((1)H NMR). The data provide additional insights into the unusually high cross-link density found in mature beaks. Furthermore, we propose both a low molecular weight catechol, and peptidyl-dopa, to be sclerotization agents of squid beak. This appears to represent a new strategy for forming hard tissue in animals. The interplay between covalent cross-linking and dehydration on the graded properties of the beaks is discussed.

The Transition from Stiff to Compliant Materials in Squid Beaks

PubMed Central

Miserez, Ali; Schneberk, Todd; Sun, Chengjun; Zok, Frank W.; Waite, J. Herbert

2009-01-01

The beak of the Humboldt squid Dosidicus gigas represents one of the hardest and stiffest wholly organic materials known. As it is deeply embedded within the soft buccal envelope, the manner in which impact forces are transmitted between beak and envelope is a matter of considerable scientific interest. Here, we show that the hydrated beak exhibits a large stiffness gradient, spanning two orders of magnitude from the tip to the base. This gradient is correlated with a chemical gradient involving mixtures of chitin, water, and His-rich proteins that contain 3,4-dihydroxyphenyl-l-alanine (dopa) and undergo extensive stabilization by histidyl-dopa cross-link formation. These findings may serve as a foundation for identifying design principles for attaching mechanically mismatched materials in engineering and biological applications. PMID:18369144

The transition from stiff to compliant materials in squid beaks.

PubMed

Miserez, Ali; Schneberk, Todd; Sun, Chengjun; Zok, Frank W; Waite, J Herbert

2008-03-28

The beak of the Humboldt squid Dosidicus gigas represents one of the hardest and stiffest wholly organic materials known. As it is deeply embedded within the soft buccal envelope, the manner in which impact forces are transmitted between beak and envelope is a matter of considerable scientific interest. Here, we show that the hydrated beak exhibits a large stiffness gradient, spanning two orders of magnitude from the tip to the base. This gradient is correlated with a chemical gradient involving mixtures of chitin, water, and His-rich proteins that contain 3,4-dihydroxyphenyl-L-alanine (dopa) and undergo extensive stabilization by histidyl-dopa cross-link formation. These findings may serve as a foundation for identifying design principles for attaching mechanically mismatched materials in engineering and biological applications.

The Transition from Stiff to Compliant Materials in Squid Beaks

NASA Astrophysics Data System (ADS)

Miserez, Ali; Schneberk, Todd; Sun, Chengjun; Zok, Frank W.; Waite, J. Herbert

2008-03-01

The beak of the Humboldt squid Dosidicus gigas represents one of the hardest and stiffest wholly organic materials known. As it is deeply embedded within the soft buccal envelope, the manner in which impact forces are transmitted between beak and envelope is a matter of considerable scientific interest. Here, we show that the hydrated beak exhibits a large stiffness gradient, spanning two orders of magnitude from the tip to the base. This gradient is correlated with a chemical gradient involving mixtures of chitin, water, and His-rich proteins that contain 3,4-dihydroxyphenyl-L-alanine (dopa) and undergo extensive stabilization by histidyl-dopa cross-link formation. These findings may serve as a foundation for identifying design principles for attaching mechanically mismatched materials in engineering and biological applications.

Metabolic suppression during protracted exposure to hypoxia in the jumbo squid, Dosidicus gigas, living in an oxygen minimum zone.

PubMed

Seibel, Brad A; Häfker, N Sören; Trübenbach, Katja; Zhang, Jing; Tessier, Shannon N; Pörtner, Hans-Otto; Rosa, Rui; Storey, Kenneth B

2014-07-15

The jumbo squid, Dosidicus gigas, can survive extended forays into the oxygen minimum zone (OMZ) of the Eastern Pacific Ocean. Previous studies have demonstrated reduced oxygen consumption and a limited anaerobic contribution to ATP production, suggesting the capacity for substantial metabolic suppression during hypoxic exposure. Here, we provide a more complete description of energy metabolism and explore the expression of proteins indicative of transcriptional and translational arrest that may contribute to metabolic suppression. We demonstrate a suppression of total ATP demand under hypoxic conditions (1% oxygen, PO2 =0.8 kPa) in both juveniles (52%) and adults (35%) of the jumbo squid. Oxygen consumption rates are reduced to 20% under hypoxia relative to air-saturated controls. Concentrations of arginine phosphate (Arg-P) and ATP declined initially, reaching a new steady state (~30% of controls) after the first hour of hypoxic exposure. Octopine began accumulating after the first hour of hypoxic exposure, once Arg-P breakdown resulted in sufficient free arginine for substrate. Octopine reached levels near 30 mmol g(-1) after 3.4 h of hypoxic exposure. Succinate did increase through hypoxia but contributed minimally to total ATP production. Glycogenolysis in mantle muscle presumably serves to maintain muscle functionality and balance energetics during hypoxia. We provide evidence that post-translational modifications on histone proteins and translation factors serve as a primary means of energy conservation and that select components of the stress response are altered in hypoxic squids. Reduced ATP consumption under hypoxia serves to maintain ATP levels, prolong fuel store use and minimize the accumulation of acidic intermediates of anaerobic ATP-generating pathways during prolonged diel forays into the OMZ. Metabolic suppression likely limits active, daytime foraging at depth in the core of the OMZ, but confers an energetic advantage over competitors that must remain in warm, oxygenated surface waters. Moreover, the capacity for metabolic suppression provides habitat flexibility as OMZs expand as a result of climate change. © 2014. Published by The Company of Biologists Ltd.

Relationships between morphometrical properties and the texture of an extrusion-expanded snack made from squid mantle (Dosidicus gigas).

PubMed

Valenzuela-Lagarda, José Luis; García-Armenta, Evangelina; Pacheco-Aguilar, Ramón; Gutiérrez-Dorado, Roberto; Mazorra-Manzano, Miguel Ángel; Lugo-Sánchez, María Elena; Muy-Rangel, María Dolores

2018-01-24

The giant squid (Dosidicus gigas) is a species of commercial interest as a source of protein, and it can be developed into ready-to-eat food products, including expanded extrusion snacks (EES). EES are prepared primarily from starch; however, adding animal protein increases the nutritional contents. The objective of this study was to evaluate the effect of the protein-carbohydrate interactions on the physical and morphological characteristics of an EES made of squid mantle and potato-corn flour. The independent variable was the squid mantle content (40, 60, 80, and 100%) and two controls (0 1  = 100% potato, 0 2  = 100% corn). The expansion rate (ER) of the sample is significantly minor (p < .5) when the squid mantle content increases ER = 2.0, 1.8 1.4 to 40, 60, and 80%, respectively. In samples with more protein, crispness and crunchiness were reduced, whereas the hardness increased. Digital imaging analysis indicated that the interaction between protein and starch causes significant morphometric changes to the fractal dimension (2.665-2.739) and lacunarity (0.61-1.29). The results showed that it is possible to incorporate up to 60% squid mantle to prepare EES that possess texture and morphometric characteristics competitive in reported studies with snacks usually incorporating flours, corn, and wheat in the formulations. The giant squid is a very attractive species because its meat has low caloric intake, high protein content, and is an important source of omega 3 fatty acids. Despite the desirable qualities of the squid meat its consumption is very low due to the low diffusion of the properties of its meat, acid, and ammoniacal flavor, rigid texture that requires prolonged cooking times and lack of alternatives of consumption. In Mexico, this type of squid is mainly destined for export as frozen mantle and products with little added value, which generates little economic benefit. Therefore, the results of this research may be of interest to the squid processing industry, which demands new forms of consumption of this marine species to increase their commercialization and added value. © 2018 Wiley Periodicals, Inc.

Range expansion of the jumbo squid in the NE Pacific: δ15N decrypts multiple origins, migration and habitat use.

PubMed

Ruiz-Cooley, Rocio I; Ballance, Lisa T; McCarthy, Matthew D

2013-01-01

Coincident with climate shifts and anthropogenic perturbations, the highly voracious jumbo squid Dosidicus gigas reached unprecedented northern latitudes along the NE Pacific margin post 1997-98. The physical or biological drivers of this expansion, as well as its ecological consequences remain unknown. Here, novel analysis from both bulk tissues and individual amino acids (Phenylalanine; Phe and Glutamic acid; Glu) in both gladii and muscle of D. gigas captured in the Northern California Current System (NCCS) documents for the first time multiple geographic origins and migration. Phe δ(15)N values, a proxy for habitat baseline δ(15)N values, confirm at least three different geographic origins that were initially detected by highly variable bulk δ(15)N values in gladii for squid at small sizes (<30 cm gladii length). In contrast, bulk δ(15)N values from gladii of large squid (>60 cm) converged, indicating feeding in a common ecosystem. The strong latitudinal gradient in Phe δ(15)N values from composite muscle samples further confirmed residency at a point in time for large squid in the NCCS. These results contrast with previous ideas, and indicate that small squid are highly migratory, move into the NCCS from two or more distinct geographic origins, and use this ecosystem mainly for feeding. These results represent the first direct information on the origins, immigration and habitat use of this key "invasive" predator in the NCCS, with wide implications for understanding both the mechanisms of periodic D. gigas population range expansions, and effects on ecosystem trophic structure.

Range Expansion of the Jumbo Squid in the NE Pacific: δ15N Decrypts Multiple Origins, Migration and Habitat Use

PubMed Central

Ruiz-Cooley, Rocio I.; Ballance, Lisa T.; McCarthy, Matthew D.

2013-01-01

Coincident with climate shifts and anthropogenic perturbations, the highly voracious jumbo squid Dosidicus gigas reached unprecedented northern latitudes along the NE Pacific margin post 1997–98. The physical or biological drivers of this expansion, as well as its ecological consequences remain unknown. Here, novel analysis from both bulk tissues and individual amino acids (Phenylalanine; Phe and Glutamic acid; Glu) in both gladii and muscle of D. gigas captured in the Northern California Current System (NCCS) documents for the first time multiple geographic origins and migration. Phe δ15N values, a proxy for habitat baseline δ15N values, confirm at least three different geographic origins that were initially detected by highly variable bulk δ15N values in gladii for squid at small sizes (<30 cm gladii length). In contrast, bulk δ15N values from gladii of large squid (>60 cm) converged, indicating feeding in a common ecosystem. The strong latitudinal gradient in Phe δ15N values from composite muscle samples further confirmed residency at a point in time for large squid in the NCCS. These results contrast with previous ideas, and indicate that small squid are highly migratory, move into the NCCS from two or more distinct geographic origins, and use this ecosystem mainly for feeding. These results represent the first direct information on the origins, immigration and habitat use of this key “invasive” predator in the NCCS, with wide implications for understanding both the mechanisms of periodic D. gigas population range expansions, and effects on ecosystem trophic structure. PMID:23527242

Identification of four squid species by quantitative real-time polymerase chain reaction.

PubMed

Ye, Jian; Feng, Junli; Liu, Shasha; Zhang, Yanping; Jiang, Xiaona; Dai, Zhiyuan

2016-02-01

Squids are distributed worldwide, including many species of commercial importance, and they are often made into varieties of flavor foods. The rapid identification methods for squid species especially their processed products, however, have not been well developed. In this study, quantitative real-time PCR (qPCR) systems based on specific primers and TaqMan probes have been established for rapid and accurate identification of four common squid species (Ommastrephes bartramii, Dosidicus gigas, Illex argentinus, Todarodes pacificus) in Chinese domestic market. After analyzing mitochondrial genes reported in GenBank, the mitochondrial cytochrome b (Cytb) gene was selected for O. bartramii detection, cytochrome c oxidase subunit I (COI) gene for D. gigas and T. Pacificus detection, ATPase subunit 6 (ATPase 6) gene for I. Argentinus detection, and 12S ribosomal RNA (12S rDNA) gene for designing Ommastrephidae-specific primers and probe. As a result, all the TaqMan systems are of good performance, and efficiency of each reaction was calculated by making standard curves. This method could detect target species either in single or mixed squid specimen, and it was applied to identify 12 squid processed products successfully. Thus, it would play an important role in fulfilling labeling regulations and squid fishery control. Copyright © 2016 Elsevier Ltd. All rights reserved.

Using Different Standardized Methods for Species Identification: A Case Study Using Beaks from Three Ommastrephid Species

NASA Astrophysics Data System (ADS)

Hu, Guanyu; Fang, Zhou; Liu, Bilin; Chen, Xinjun; Staples, Kevin; Chen, Yong

2018-04-01

The cephalopod beak is a vital hard structure with a stable configuration and has been widely used for the identification of cephalopod species. This study was conducted to determine the best standardization method for identifying different species by measuring 12 morphological variables of the beaks of Illex argentinus, Ommastrephes bartramii, and Dosidicus gigas that were collected by Chinese jigging vessels. To remove the effects of size, these morphometric variables were standardized using three methods. The average ratios of the upper beak morphological variables and upper crest length of O. bartramii and D. gigas were found to be greater than those of I. argentinus. However, for lower beaks, only the average of LRL (lower rostrum length)/ LCL (lower crest length), LRW (lower rostrum width)/ LCL, and LLWL (lower lateral wall length)/ LCL of O. bartramii and D. gigas were greater than those of I. argentinus. The ratios of beak morphological variables and crest length were found to be all significantly different among the three species ( P < 0.001). Among the three standardization methods, the correct classification rate of stepwise discriminant analysis (SDA) was the highest using the ratios of beak morphological variables and crest length. Compared with hood length, the correct classification rate was slightly higher when using beak variables standardized by crest length using an allometric model. The correct classification rate of the lower beak was also found to be greater than that of the upper beak. This study indicates that the ratios of beak morphological variables to crest length could be used for interspecies and intraspecies identification. Meanwhile, the lower beak variables were found to be more effective than upper beak variables in classifying beaks found in the stomachs of predators.

Radioimmunoassay of dermorphin-like peptides in mammalian and non-mammalian tissues.

PubMed

Negri, L; Melchiorri, P; Erspamer, G F; Erspamer, V

1981-01-01

A selective RIA for D-Ala2-Dermorphin (Der), a natural peptide extracted from amphibian skin, has been developed using an antibody raised in rabbits against Der which has been coupled to BSA through its phenolic hydroxyl groups of tyrosine residues with 2,4-Dichloro-6-methoxy-1,3,5-triazine. The cross-reactivity of this antibody with dermorphin analogs, C- and N-terminal fragments of dermorphin molecule, some opioid and gastrointestinal peptides was tested. Der-like immunoreactivity has been identified in tissue extracts of rats, frog and cephalopoda. Der-like peptides were purified by passing methanol extracts of the tissues through a Sephadex G25 column (16 x 100 cm) eluted with 0.1 M acetic acid at 4 degrees C. Der-like immunoreactivity from neural tissue of Dosidicus gigas, Eledone moscata, and rat brain showed a good agreement with an authentic sample of synthetic dermorphin.

Infiltration of chitin by protein coacervates defines the squid beak mechanical gradient.

PubMed

Tan, YerPeng; Hoon, Shawn; Guerette, Paul A; Wei, Wei; Ghadban, Ali; Hao, Cai; Miserez, Ali; Waite, J Herbert

2015-07-01

The beak of the jumbo squid Dosidicus gigas is a fascinating example of how seamlessly nature builds with mechanically mismatched materials. A 200-fold stiffness gradient begins in the hydrated chitin of the soft beak base and gradually increases to maximum stiffness in the dehydrated distal rostrum. Here, we combined RNA-Seq and proteomics to show that the beak contains two protein families. One family consists of chitin-binding proteins (DgCBPs) that physically join chitin chains, whereas the other family comprises highly modular histidine-rich proteins (DgHBPs). We propose that DgHBPs play multiple key roles during beak bioprocessing, first by forming concentrated coacervate solutions that diffuse into the DgCBP-chitin scaffold, and second by inducing crosslinking via an abundant GHG sequence motif. These processes generate spatially controlled desolvation, resulting in the impressive biomechanical gradient. Our findings provide novel molecular-scale strategies for designing functional gradient materials.

Potential role for microRNA in regulating hypoxia-induced metabolic suppression in jumbo squids.

PubMed

Hadj-Moussa, Hanane; Logan, Samantha M; Seibel, Brad A; Storey, Kenneth B

2018-05-02

At night, Humboldt squid (Dosidicus gigas) rise to the ocean's surface to feed, but come morning, they descend into the ocean's oxygen minimum zone where they can avoid predators but must deal with severe hypoxia, high pressure, and very cold water. To survive this extreme environment, squid use various adaptations to enter a hypometabolic state characterized by metabolic rate suppression by 35-52%, relative to normoxic conditions. The molecular mechanisms facilitating this metabolic flexibility have yet to be elucidated in hypometabolic squid. Herein, we report the first investigation of the role of microRNAs, a rapid and reversible post-transcriptional master regulator of virtually all biological functions, in cephalopods. We examined expression levels of 39 highly-conserved invertebrate microRNAs in D. gigas brain, mantle muscle, and branchial heart, comparing hypoxic and normoxic conditions. Hypoxia-inducible microRNAs are potentially involved in facilitating neuroprotection, anti-apoptosis, and regenerative mechanisms in brain; inhibiting apoptosis and cell proliferation while conserving energy in heart; and limiting damage by reactive oxygen species and apoptosis in muscle. Rather than orchestrate global metabolic rate depression, the majority of hypoxia-inducible microRNAs identified are involved in promoting cytoprotective mechanisms, suggesting a regulatory role for microRNA in hypoxic marine invertebrates that sets the stage for mechanistic analyses. Copyright © 2018 Elsevier B.V. All rights reserved.

Physical-chemical studies of proteins of squid nerve axoplasm, with special reference to the axon fibrous protein.

PubMed

DAVISON, P F; TAYLOR, E W

1960-03-01

The proteins in the axoplasm of the squid, Dosidicus gigas, have been resolved electrophoretically into a major fraction including the fibrous protein, and possibly its structural subunits, and a minor fraction including at least two proteins with low sedimentation coefficients. A partially reversible change in the structure of the fibrous protein occurs under the action of 0.4 M salt or high pH. These experiments have been interpreted to indicate that in the intact fiber one, or a few, protofibrils are arranged helically or longitudinally along the fiber axis, and linked by electrostatic bonds. On the dissociation of these bonds the separated protofibrils assume a less extended form and sediment more rapidly than the intact fibers. Some material with a lower sedimentation rate is also released on the dissociation. This fraction may comprise smaller chain fragments. The volume fraction and the approximate refractive index of the fibers have been calculated.

Physical-Chemical Studies of Proteins of Squid Nerve Axoplasm, with Special Reference to the Axon Fibrous Protein

PubMed Central

Davison, Peter F.; Taylor, Edwin W.

1960-01-01

The proteins in the axoplasm of the squid, Dosidicus gigas, have been resolved electrophoretically into a major fraction including the fibrous protein, and possibly its structural subunits, and a minor fraction including at least two proteins with low sedimentation coefficients. A partially reversible change in the structure of the fibrous protein occurs under the action of 0.4 M salt or high pH. These experiments have been interpreted to indicate that in the intact fiber one, or a few, protofibrils are arranged helically or longitudinally along the fiber axis, and linked by electrostatic bonds. On the dissociation of these bonds the separated protofibrils assume a less extended form and sediment more rapidly than the intact fibers. Some material with a lower sedimentation rate is also released on the dissociation. This fraction may comprise smaller chain fragments. The volume fraction and the approximate refractive index of the fibers have been calculated. PMID:13814536

Slow swimming, fast strikes: effects of feeding behavior on scaling of anaerobic metabolism in epipelagic squid.

PubMed

Trueblood, Lloyd A; Seibel, Brad A

2014-08-01

Many pelagic fishes engage prey at high speeds supported by high metabolic rates and anaerobic metabolic capacity. Epipelagic squids are reported to have among the highest metabolic rates in the oceans as a result of demanding foraging strategies and the use of jet propulsion, which is inherently inefficient. This study examined enzymatic proxies of anaerobic metabolism in two species of pelagic squid, Dosidicus gigas and Doryteuthis pealeii (Lesueur 1821), over a size range of six orders of magnitude. We hypothesized that activity of the anaerobically poised enzymes would be high and increase with size as in ecologically similar fishes. In contrast, we demonstrate that anaerobic metabolic capacity in these organisms scales negatively with body mass. We explored several cephalopod-specific traits, such as the use of tentacles to capture prey, body morphology and reduced relative prey size of adult squids, that may create a diminished reliance on anaerobically fueled burst activity during prey capture in large animals. © 2014. Published by The Company of Biologists Ltd.

Mass spectrometric survey of peptides in cephalopods with an emphasis on the FMRFamide-related peptides.

PubMed

Sweedler, J V; Li, L; Floyd, P; Gilly, W

2000-12-01

A matrix-assisted laser desorption/ionization (MALDI) mass spectrometric (MS) survey of the major peptides in the stellar, fin and pallial nerves and the posterior chromatophore lobe of the cephalopods Sepia officinalis, Loligo opalescens and Dosidicus gigas has been performed. Although a large number of putative peptides are distinct among the three species, several molecular masses are conserved. In addition to peptides, characterization of the lipid content of the nerves is reported, and these lipid peaks account for many of the lower molecular masses observed. One conserved set of peaks corresponds to the FMRFamide-related peptides (FRPs). The Loligo opalescens FMRFa gene has been sequenced. It encodes a 331 amino acid residue prohormone that is processed into 14 FRPs, which are both predicted by the nucleotide sequence and confirmed by MALDI MS. The FRPs predicted by this gene (FMRFa, FLRFa/FIRFa and ALSGDAFLRFa) are observed in all three species, indicating that members of this peptide family are highly conserved across cephalopods.

Simultaneous measurements of magnesium, calcium and sodium influxes in perfused squid giant axons under membrane potential control.

PubMed

Rojas, E; Taylor, R E

1975-10-01

1. Giant axons from the squids Dosidicus gigas, Loligo forbesi and Loligo vulgaris were internally perfused with 550 or 275 mM KF plus sucrose and bathed in artificial sea water containing 45Ca, 28Mg or mixtures of 45Ca-28Mg or 45Ca-22Na. Resting influxes and extra influxes during voltage-clamp pulses were measured by collecting and counting the internal perfusate. 2. For Dosidicus axons in 10 mM-CaCl2 the resting influx of calcium was 0-016 +/- 0-007 p-mole/cm2 sec and a linear function of external concentration. For two experiments in 10 and 84-7 mM-CaCl2, 100 nM tetrodotoxin had no effect. Resting calcium influx in 10 mM-CaCl2 was 0-017 +/- 0-013 p-mole/cm2 sec for Loligo axons. 3. With 55 mM-MgCl2 outside the average resting magnesium influx was 0-124 +/- 0-080 p-mole/cm2 sec for Loligo axons. Discarding one aberrant point the value is 0-105 +/- 0-046 which is not significantly different from the resting calcium influx for Dosidicus fibres in 55 mM-CaCl2, given as 0-094 p-mole/cm2 sec by the regression line shown in Fig. 1. In two experiments 150 nM tetrodotoxin had no effect. 4. With 430 mM-NaCl outside 100 nM tetrodotoxin reduced the average resting influx of sodium in Dosidicus axon from 27-7 +/- 4-5 to 25-1 +/- 6-2 p-mole/cm2 sec and for Loligo fibres in 460 mM-NaCl from 50-5 +/- 4 to 20 +/- 8 p-mole/cm2 sec. 5. Using depolarizing pulses of various durations, the extra calcium influx occurred in two phases. The early phase was eliminated by external application of tetrodotoxin. The results of analysis are consistent with, but do not rigorously demonstrate, the conclusion that the tetrodotoxin sensitive calcium entry is flowing through the normal sodium channels (cf. Baker, Hodgkin & Ridgway, 1971). 6. Measurements of extra influxes using 22Na and 45Ca simultaneously indicate that the time courses of tetrodotoxin sensitive calcium and sodium entry are similar but not necessarily identical. It is very doubtful that any significant calcium entry occurs before the sodium or is involved in the activation of the sodium system. 7. These measurements confirm for Loligo, as previously shown for Dosidicus axons, that the magnitude and time course of the sodium entry during a depolarizing pulse deduced from electrical measurements is the same as that measured with 22Na. 8. Using 28Mg, or mixtures of 45Ca and 28Mg, we observed a single phase of magnesium entry which was insensitive to external tetrodotoxin or internal tetraethyl ammonium. The magnitude of the magnesium influx was considerably greater than the calcium extra entry and large enough to have been detected in the experiments of Meves & Vogel (1973) if it represented current. 9. We suggest the possibility that the calcium and magnesium extra influxes, after external treatment with tetrodotoxin, during a depolarizing pulse, do not contribute to the measured current.

Simultaneous measurements of magnesium, calcium and sodium influxes in perfused squid giant axons under membrane potential control.

PubMed Central

Rojas, E; Taylor, R E

1975-01-01

1. Giant axons from the squids Dosidicus gigas, Loligo forbesi and Loligo vulgaris were internally perfused with 550 or 275 mM KF plus sucrose and bathed in artificial sea water containing 45Ca, 28Mg or mixtures of 45Ca-28Mg or 45Ca-22Na. Resting influxes and extra influxes during voltage-clamp pulses were measured by collecting and counting the internal perfusate. 2. For Dosidicus axons in 10 mM-CaCl2 the resting influx of calcium was 0-016 +/- 0-007 p-mole/cm2 sec and a linear function of external concentration. For two experiments in 10 and 84-7 mM-CaCl2, 100 nM tetrodotoxin had no effect. Resting calcium influx in 10 mM-CaCl2 was 0-017 +/- 0-013 p-mole/cm2 sec for Loligo axons. 3. With 55 mM-MgCl2 outside the average resting magnesium influx was 0-124 +/- 0-080 p-mole/cm2 sec for Loligo axons. Discarding one aberrant point the value is 0-105 +/- 0-046 which is not significantly different from the resting calcium influx for Dosidicus fibres in 55 mM-CaCl2, given as 0-094 p-mole/cm2 sec by the regression line shown in Fig. 1. In two experiments 150 nM tetrodotoxin had no effect. 4. With 430 mM-NaCl outside 100 nM tetrodotoxin reduced the average resting influx of sodium in Dosidicus axon from 27-7 +/- 4-5 to 25-1 +/- 6-2 p-mole/cm2 sec and for Loligo fibres in 460 mM-NaCl from 50-5 +/- 4 to 20 +/- 8 p-mole/cm2 sec. 5. Using depolarizing pulses of various durations, the extra calcium influx occurred in two phases. The early phase was eliminated by external application of tetrodotoxin. The results of analysis are consistent with, but do not rigorously demonstrate, the conclusion that the tetrodotoxin sensitive calcium entry is flowing through the normal sodium channels (cf. Baker, Hodgkin & Ridgway, 1971). 6. Measurements of extra influxes using 22Na and 45Ca simultaneously indicate that the time courses of tetrodotoxin sensitive calcium and sodium entry are similar but not necessarily identical. It is very doubtful that any significant calcium entry occurs before the sodium or is involved in the activation of the sodium system. 7. These measurements confirm for Loligo, as previously shown for Dosidicus axons, that the magnitude and time course of the sodium entry during a depolarizing pulse deduced from electrical measurements is the same as that measured with 22Na. 8. Using 28Mg, or mixtures of 45Ca and 28Mg, we observed a single phase of magnesium entry which was insensitive to external tetrodotoxin or internal tetraethyl ammonium. The magnitude of the magnesium influx was considerably greater than the calcium extra entry and large enough to have been detected in the experiments of Meves & Vogel (1973) if it represented current. 9. We suggest the possibility that the calcium and magnesium extra influxes, after external treatment with tetrodotoxin, during a depolarizing pulse, do not contribute to the measured current. PMID:1202193

Methods to obtain protein concentrates from jumbo squid (Dosidicus gigas) and evaluation of their functionality.

PubMed

Galvez-Rongel, A; Ezquerra-Brauer, J M; Ocano-Higuera, V M; Ramirez-Wong, B; Torres-Arreola, W; Rouzaud-Sandez, O; Marquez-Rios, E

2014-03-01

Jumbo squid is an important fishery resource in Mexico, and its muscle is lean and white and it has a very low price in the market. It is abundant, but with little or nothing added value, therefore is necessary to search alternatives of processing. Due to muscle characteristics, the aim of this study was to obtain protein concentrates using different methods. They were obtained by means of acidic (acid protein concentrates) and alkaline (alkaline protein concentrates) dissolution. Moreover, a protein concentrate was obtained by direct isoelectric precipitation and by the traditional method (neutral protein concentrates). The yield with better results was alkaline protein concentrates (63.58 ± 1.8%). The gel hardness was significantly different (p < 0.05), especially for the alkaline protein concentrates. The acid protein concentrates, isoelectric precipitation and alkaline protein concentrates were better with regard to the neutral protein concentrates, concerning the emulsifying and foaming properties. The protein concentrates by means of alkaline dissolution gave a better gelling property, but all the processes had the potential to obtain protein with emulsifying and foaming properties.

Sodium movements in perfused squid giant axons. Passive fluxes.

PubMed

Rojas, E; Canessa-Fischer, M

1968-08-01

Sodium movements in internally perfused giant axons from the squid Dosidicus gigas were studied with varying internal sodium concentrations and with fluoride as the internal anion. It was found that as the internal concentration of sodium was increased from 2 to 200 mM the resting sodium efflux increased from 0.09 to 34.0 pmoles/cm(2)sec and the average resting sodium influx increased from 42.9 to 64.5 pmoles/cm(2)sec but this last change was not statistically significant. When perfusing with a mixture of 500 mM K glutamate and 100 mM Na glutamate the resting efflux was 10 +/- 3 pmoles/cm(2)sec and 41 +/- 10 pmoles/cm(2)sec for sodium influx. Increasing the internal sodium concentration also increased both the extra influx and the extra efflux of sodium due to impulse propagation. At any given internal sodium concentration the net extra influx was about 5 pmoles/cm(2)impulse. This finding supports the notion that the inward current generated in a propagated action potential can be completely accounted for by movements of sodium.

Sodium and potassium conductance changes during a membrane action potential.

PubMed

Bezanilla, F; Rojas, E; Taylor, R E

1970-12-01

1. A method for turning a membrane potential control system on and off in less than 10 musec is described. This method was used to record membrane currents in perfused giant axons from Dosidicus gigas and Loligo forbesi after turning on the voltage clamp system at various times during the course of a membrane action potential.2. The membrane current measured just after the capacity charging transient was found to have an almost linear relation to the controlled membrane potential.3. The total membrane conductance taken from these current-voltage curves was found to have a time course during the action potential similar to that found by Cole & Curtis (1939).4. The instantaneous current voltage curves were linear enough to make it possible to obtain a good estimate of the individual sodium and potassium channel conductances, either algebraically or by clamping to the sodium, or potassium, reversal potentials. Good general agreement was obtained with the predictions of the Hodgkin-Huxley equations.5. We consider these results to constitute the first direct experimental demonstration of the conductance changes to sodium and potassium during the course of an action potential.

Sodium Movements in Perfused Squid Giant Axons

PubMed Central

Rojas, Eduardo; Canessa-Fischer, Mitzy

1968-01-01

Sodium movements in internally perfused giant axons from the squid Dosidicus gigas were studied with varying internal sodium concentrations and with fluoride as the internal anion. It was found that as the internal concentration of sodium was increased from 2 to 200 mM the resting sodium efflux increased from 0.09 to 34.0 pmoles/cm2sec and the average resting sodium influx increased from 42.9 to 64.5 pmoles/cm2sec but this last change was not statistically significant. When perfusing with a mixture of 500 mM K glutamate and 100 mM Na glutamate the resting efflux was 10 ± 3 pmoles/cm2sec and 41 ± 10 pmoles/cm2sec for sodium influx. Increasing the internal sodium concentration also increased both the extra influx and the extra efflux of sodium due to impulse propagation. At any given internal sodium concentration the net extra influx was about 5 pmoles/cm2impulse. This finding supports the notion that the inward current generated in a propagated action potential can be completely accounted for by movements of sodium. PMID:5672003

Hypoxia tolerance and antioxidant defense system of juvenile jumbo squids in oxygen minimum zones

NASA Astrophysics Data System (ADS)

Trübenbach, Katja; Teixeira, Tatiana; Diniz, Mário; Rosa, Rui

2013-10-01

Jumbo squid (Dosidicus gigas) is a large oceanic squid endemic off the Eastern Tropical Pacific that undertakes diel vertical migrations into mesopelagic oxygen minimum zones. One of the expected physiological effects of such migration is the generation of reactive oxygen species (ROS) at the surface, promoted by the transition between hypoxia and reoxygenation states. The aim of this study was to investigate the energy expenditure rates and the antioxidant stress strategies of juvenile D. gigas under normoxia and hypoxia, namely by quantifying oxygen consumption rates, antioxidant enzyme activities [including superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST)], heat shock protein expression (Hsp70/Hsc70), and lipid peroxidation [malondialdehyde (MDA) levels]. A high significant decrease (68%) in squid's metabolic rates was observed during hypoxia (p<0.05). This process of metabolic suppression was followed by a significant increase in Hsp70/Hsc70 expression (p<0.05), which may be interpreted as a strategy to prevent post-hypoxic oxidative damage during the squid's night upwards migration to the surface ocean. On the other hand, in normoxia, the higher SOD and CAT activities seemed to be a strategy to cope with the reoxygenation process, and may constitute an integrated stress response at shallower depths. GST activity and MDA concentrations did not change significantly from normoxia to hypoxia (p>0.05), with the latter indicating no enhancement of lipid peroxidation (i.e. cellular damage) at the warmer and normoxic surface waters. The understanding of such physiological strategies that are linked to oxygen deprivation and reoxygenation phases may provide valuable information about how this species is quickly responding to the impacts of environmental stressors coupled with global climate change.

Effects of redox and sulfhydryl reagents on the bioelectric properties of the giant axon of the squid.

PubMed

Huneeus-Cox, F; Fernandez, H L; Smith, B H

1966-09-01

The effects of internally and externally applied sulfhydryl reagents on the bioelectric properties of the giant axon of the squid Loligo pealeii and Dosidicus gigas were studied. Cysteine-HCl (400 mM, pH 7.3) was used to remove axoplasm from the perfusion channel. Oxidizing agents (1 to 60 mM) tended to increase the duration of the action potential and had a slow, irreversible blocking effect when perfused internally; the membrane potential was little affected. Reducing agents applied internally caused a decrease in the spike duration without affecting its height or the membrane potential, although at high concentrations there was reversible deterioration of the action potential. Both external and internal perfusion of mercaptide-forming reagents caused deterioration in the action and membrane potentials with conduction block occurring in 5 to 45 min. 2-mercaptoethanol reversed the effects. Thiol alkylating reagents, iodoacetate and iodoacetamide, were without effect. N-ethylmaleimide did, however, block. Tests with chelating agents for nonheme iron in the membrane brought about no change in the electrical parameters. The implications of the present findings with regard to the macromolecular mechanism of excitation are discussed.

Sodium and potassium conductance changes during a membrane action potential

PubMed Central

Bezanilla, Francisco; Rojas, Eduardo; Taylor, Robert E.

1970-01-01

1. A method for turning a membrane potential control system on and off in less than 10 μsec is described. This method was used to record membrane currents in perfused giant axons from Dosidicus gigas and Loligo forbesi after turning on the voltage clamp system at various times during the course of a membrane action potential. 2. The membrane current measured just after the capacity charging transient was found to have an almost linear relation to the controlled membrane potential. 3. The total membrane conductance taken from these current—voltage curves was found to have a time course during the action potential similar to that found by Cole & Curtis (1939). 4. The instantaneous current voltage curves were linear enough to make it possible to obtain a good estimate of the individual sodium and potassium channel conductances, either algebraically or by clamping to the sodium, or potassium, reversal potentials. Good general agreement was obtained with the predictions of the Hodgkin—Huxley equations. 5. We consider these results to constitute the first direct experimental demonstration of the conductance changes to sodium and potassium during the course of an action potential. PMID:5505231

Isolation and properties of AMP deaminase from jumbo squid (Dosidicus gigas) mantle muscle from the Gulf of California, Mexico.

PubMed

Marquez-Rios, E; Pacheco-Aguilar, R; Castillo-Yañez, F J; Figueroa-Soto, C G; Ezquerra-Brauer, J M; Gollas-Galvan, T

2008-09-01

Adenosine monophosphate (AMP) deaminase was purified from jumbo squid mantle muscle by chromatography in cellulose phosphate, Q-Fast and 5'-AMP sepharose. Specific activity of 2.5U/mg protein, 4.5% recovery and 133.68 purification fold were obtained at the end of the experiment. SDS-PAGE showed a single band with 87kDa molecular mass, native PAGE proved a band of 178kDa, whereas gel filtration detected a 180kDa protein, suggesting the homodimeric nature of this enzyme, in which subunits are not linked by covalent forces. Isoelectric focusing of this enzyme showed a pI of 5.76, which agrees with pI values of AMP deaminase from other invertebrate organisms. AMP deaminase presented a kinetic sigmoidal plot with Vmax of 1.16μM/min/mg, Km of 13mM, Kcat of 3.48μM.s(-1) and a Kcat/Km of 267 (mol/L)(-1).s(-1). The apparent relative low catalytic activity of jumbo squid muscle AMP deaminase in the absence of positive effectors is similar to that reported for homologous enzymes in other invertebrate organisms. Copyright © 2008 Elsevier Ltd. All rights reserved.

Effects of Redox and Sulfhydryl Reagents on the Bioelectric Properties of the Giant Axon of the Squid

PubMed Central

Huneeus-Cox, F.; Fernandez, H. L.; Smith, B. H.

1966-01-01

The effects of internally and externally applied sulfhydryl reagents on the bioelectric properties of the giant axon of the squid Loligo pealeii and Dosidicus gigas were studied. Cysteine-HCl (400 mM, pH 7.3) was used to remove axoplasm from the perfusion channel. Oxidizing agents (1 to 60 mM) tended to increase the duration of the action potential and had a slow, irreversible blocking effect when perfused internally; the membrane potential was little affected. Reducing agents applied internally caused a decrease in the spike duration without affecting its height or the membrane potential, although at high concentrations there was reversible deterioration of the action potential. Both external and internal perfusion of mercaptide-forming reagents caused deterioration in the action and membrane potentials with conduction block occurring in 5 to 45 min. 2-mercaptoethanol reversed the effects. Thiol alkylating reagents, iodoacetate and iodoacetamide, were without effect. N-ethylmaleimide did, however, block. Tests with chelating agents for nonheme iron in the membrane brought about no change in the electrical parameters. The implications of the present findings with regard to the macromolecular mechanism of excitation are discussed. ImagesFigure 1 PMID:5970570

Purification and in vitro antioxidative effects of giant squid muscle peptides on free radical-mediated oxidative systems.

PubMed

Rajapakse, Niranjan; Mendis, Eresha; Byun, Hee-Guk; Kim, Se-Kwon

2005-09-01

Low molecular weight peptides obtained from ultrafiltration (UF) of giant squid (Dosidicus gigas) muscle protein were studied for their antioxidative effects in different in vitro oxidative systems. The most potent two peptides, Asn-Ala-Asp-Phe-Gly-Leu-Asn-Gly-Leu-Glu-Gly-Leu-Ala (1307 Da) and Asn-Gly-Leu-Glu-Gly-Leu-Lys (747 Da), exhibited their antioxidant potential to act as chain-breaking antioxidants by inhibiting radical-mediated peroxidation of linoleic acid, and their activities were closer to highly active synthetic antioxidant, butylated hydroxytoluene. Addition of these peptides could enhance the viability of cytotoxic embryonic lung fibroblasts significantly (P<.05) at a low concentration of 50 microg/ml, and it was presumed due to the suppression of radical-induced oxidation of membrane lipids. Electron spin trapping studies revealed that the peptides were potent scavengers of free radicals in the order of carbon-centered (IC(50) 396.04 and 304.67 microM), hydroxyl (IC(50) 497.32 and 428.54 microM) and superoxide radicals (IC(50) 669.34 and 573.83 microM). Even though the exact molecular mechanism for scavenging of free radicals was unclear, unusually high hydrophobic amino acid composition (more than 75%) of giant squid muscle peptides was presumed to be involved in the observed activities.

Effects of thermal processing and various chemical substances on formaldehyde and dimethylamine formation in squid Dosidicus gigas.

PubMed

Zhu, Junli; Li, Jianrong; Jia, Jia

2012-09-01

Trimethylamine oxide (TMAO) in squid is demethylated to dimethylamine (DMA) and formaldehyde (FA) during storage and processing. This study examined the effects of thermal processing and various chemical substances on FA and DMA formation in squid. The thermal conversion of TMAO was assessed by analysing four squid and four gadoid fish species, which revealed that FA, DMA and trimethylamine (TMA) were gradually produced in squid, whereas TMA increased and FA decreased in gadoid fish. A significant increase in both FA and DMA levels was observed in the supernatant of jumbo squid with increased heating temperature and extended heating time at pH 6-7. Ferrous chloride combined with cysteine and/or ascorbate had a significantly positive effect on FA formation in the heated supernatant of jumbo squid. No significant difference was observed in the levels of Cu and Fe in squid and gadoid fish. The capability of Fe(2+) to promote the formation of FA and DMA was not completely attributable to its reducing power in squid. Non-enzymatic decomposition of TMAO was a key pathway during the thermal processing of jumbo squid, and Fe(2+) was a crucial activator in the formation of FA and DMA. Copyright © 2012 Society of Chemical Industry.

Material properties of Pacific hake, Humboldt squid, and two species of myctophids in the California Current.

PubMed

Becker, Kaylyn N; Warren, Joseph D

2015-05-01

Material properties of the flesh from three fish species (Merluccius productus, Symbolophorus californiensis, and Diaphus theta), and several body parts of the Humboldt squid (Dosidicus gigas) collected from the California Current ecosystem were measured. The density contrast relative to seawater varied within and among taxa for fish flesh (0.9919-1.036), squid soft body parts (mantle, arms, tentacle, braincase, eyes; 1.009-1.057), and squid hard body parts (beak and pen; 1.085-1.459). Effects of animal length and environmental conditions on nekton density contrast were investigated. The sound speed contrast relative to seawater varied within and among taxa for fish flesh (0.986-1.027) and Humboldt squid mantle and braincase (0.937-1.028). Material properties in this study are similar to values from previous studies on species with similar life histories. In general, the sound speed and density of soft body parts of fish and squid were 1%-3% and 1%-6%, respectively, greater than the surrounding seawater. Hard parts of the squid were significantly more dense (6%-46%) than seawater. The material properties reported here can be used to improve target strength estimates from acoustic scattering models, which could increase the accuracy of biomass estimates from acoustic surveys for these nekton.

Effect of stimulation and hyperpolarization on non-electrolyte and sodium permeability in perfused axons of squid.

PubMed

Hidalgo, C; Latorre, R

1970-11-01

1. The permeability for micro-injected [(3)H]ethylene glycol was measured in resting state and during stimulation at 100/sec in squid giant axons. No detectable changes during electrical activity were observed.2. The influxes of urethane, tritiated water, ethylene glycol, urea and sodium were measured in internally perfused squid axons. Ethylene glycol and urea influxes were determined simultaneously with sodium influxes. The electrical stimulation of the fibre produced an increase in the influx of sodium but did not alter the influxes of the non-electrolytes listed above.3. Experiments were done with the combined voltage clamp-perfusion technique. The influxes of ethylene glycol and sodium were simultaneously measured in resting state and during maximum sodium current under stimulation at 10/sec. The influx of sodium increased in these conditions but the influx of ethylene glycol remained constant. In some experiments, the fibre was hyperpolarized to 10 or 20 mV, above the resting potential and the influxes of ethylene glycol and sodium were measured. The sodium influx decreased to 60% at 20 mV above the resting potential whereas the influx of ethylene glycol remained constant.4. These results indicate that in the giant axons of the squid Dosidicus gigas, sodium and non-electrolytes fluxes are not coupled.

Synergistic effects of climate-related variables suggest future physiological impairment in a top oceanic predator.

PubMed

Rosa, Rui; Seibel, Brad A

2008-12-30

By the end of this century, anthropogenic carbon dioxide (CO(2)) emissions are expected to decrease the surface ocean pH by as much as 0.3 unit. At the same time, the ocean is expected to warm with an associated expansion of the oxygen minimum layer (OML). Thus, there is a growing demand to understand the response of the marine biota to these global changes. We show that ocean acidification will substantially depress metabolic rates (31%) and activity levels (45%) in the jumbo squid, Dosidicus gigas, a top predator in the Eastern Pacific. This effect is exacerbated by high temperature. Reduced aerobic and locomotory scope in warm, high-CO(2) surface waters will presumably impair predator-prey interactions with cascading consequences for growth, reproduction, and survival. Moreover, as the OML shoals, squids will have to retreat to these shallower, less hospitable, waters at night to feed and repay any oxygen debt that accumulates during their diel vertical migration into the OML. Thus, we demonstrate that, in the absence of adaptation or horizontal migration, the synergism between ocean acidification, global warming, and expanding hypoxia will compress the habitable depth range of the species. These interactions may ultimately define the long-term fate of this commercially and ecologically important predator.

Squid rocket science: How squid launch into air

NASA Astrophysics Data System (ADS)

O'Dor, Ron; Stewart, Julia; Gilly, William; Payne, John; Borges, Teresa Cerveira; Thys, Tierney

2013-10-01

Squid not only swim, they can also fly like rockets, accelerating through the air by forcefully expelling water out of their mantles. Using available lab and field data from four squid species, Sthenoteuthis pteropus, Dosidicus gigas, Illex illecebrosus and Loligo opalescens, including sixteen remarkable photographs of flying S. pteropus off the coast of Brazil, we compared the cost of transport in both water and air and discussed methods of maximizing power output through funnel and mantle constriction. Additionally we found that fin flaps develop at approximately the same size range as flight behaviors in these squids, consistent with previous hypotheses that flaps could function as ailerons whilst aloft. S. pteropus acceleration in air (265 body lengths [BL]/s2; 24.5m/s2) was found to exceed that in water (79BL/s2) three-fold based on estimated mantle length from still photos. Velocities in air (37BL/s; 3.4m/s) exceed those in water (11BL/s) almost four-fold. Given the obvious advantages of this extreme mode of transport, squid flight may in fact be more common than previously thought and potentially employed to reduce migration cost in addition to predation avoidance. Clearly squid flight, the role of fin flaps and funnel, and the energetic benefits are worthy of extended investigation.

Effect of stimulation and hyperpolarization on non-electrolyte and sodium permeability in perfused axons of squid

PubMed Central

Hidalgo, Cecilia; Latorre, Ramón

1970-01-01

1. The permeability for micro-injected [3H]ethylene glycol was measured in resting state and during stimulation at 100/sec in squid giant axons. No detectable changes during electrical activity were observed. 2. The influxes of urethane, tritiated water, ethylene glycol, urea and sodium were measured in internally perfused squid axons. Ethylene glycol and urea influxes were determined simultaneously with sodium influxes. The electrical stimulation of the fibre produced an increase in the influx of sodium but did not alter the influxes of the non-electrolytes listed above. 3. Experiments were done with the combined voltage clamp—perfusion technique. The influxes of ethylene glycol and sodium were simultaneously measured in resting state and during maximum sodium current under stimulation at 10/sec. The influx of sodium increased in these conditions but the influx of ethylene glycol remained constant. In some experiments, the fibre was hyperpolarized to 10 or 20 mV, above the resting potential and the influxes of ethylene glycol and sodium were measured. The sodium influx decreased to 60% at 20 mV above the resting potential whereas the influx of ethylene glycol remained constant. 4. These results indicate that in the giant axons of the squid Dosidicus gigas, sodium and non-electrolytes fluxes are not coupled. PMID:5500991

Chemical composition of inks of diverse marine molluscs suggests convergent chemical defenses.

PubMed

Derby, Charles D; Kicklighter, Cynthia E; Johnson, P M; Zhang, Xu

2007-05-01

Some marine molluscs, notably sea hares, cuttlefish, squid, and octopus, release ink when attacked by predators. The sea hare Aplysia californica releases secretions from the ink gland and opaline gland that protect individuals from injury or death from predatory spiny lobsters through a combination of mechanisms that include chemical deterrence, sensory disruption, and phagomimicry. The latter two mechanisms are facilitated by millimolar concentrations of free amino acids (FAA) in sea hare ink and opaline, which stimulate the chemosensory systems of predators, ultimately leading to escape by sea hares. We hypothesize that other inking molluscs use sensory disruption and/or phagomimicry as a chemical defense. To investigate this, we examined concentrations of 21 FAA and ammonium in the defensive secretions of nine species of inking molluscs: three sea hares (Aplysia californica, Aplysia dactylomela, Aplysia juliana) and six cephalopods (cuttlefish: Sepia officinalis; squid: Loligo pealei, Lolliguncula brevis, Dosidicus gigas; octopus: Octopus vulgaris, Octopus bimaculoides). We found millimolar levels of total FAA and ammonium in these secretions, and the FAA in highest concentration were taurine, aspartic acid, glutamic acid, alanine, and lysine. Crustaceans and fish, which are major predators of these molluscs, have specific receptor systems for these FAA. Our chemical analysis supports the hypothesis that inking molluscs have the potential to use sensory disruption and/or phagomimicry as a chemical defense.

Synergistic effects of climate-related variables suggest future physiological impairment in a top oceanic predator

PubMed Central

Rosa, Rui; Seibel, Brad A.

2008-01-01

By the end of this century, anthropogenic carbon dioxide (CO2) emissions are expected to decrease the surface ocean pH by as much as 0.3 unit. At the same time, the ocean is expected to warm with an associated expansion of the oxygen minimum layer (OML). Thus, there is a growing demand to understand the response of the marine biota to these global changes. We show that ocean acidification will substantially depress metabolic rates (31%) and activity levels (45%) in the jumbo squid, Dosidicus gigas, a top predator in the Eastern Pacific. This effect is exacerbated by high temperature. Reduced aerobic and locomotory scope in warm, high-CO2 surface waters will presumably impair predator–prey interactions with cascading consequences for growth, reproduction, and survival. Moreover, as the OML shoals, squids will have to retreat to these shallower, less hospitable, waters at night to feed and repay any oxygen debt that accumulates during their diel vertical migration into the OML. Thus, we demonstrate that, in the absence of adaptation or horizontal migration, the synergism between ocean acidification, global warming, and expanding hypoxia will compress the habitable depth range of the species. These interactions may ultimately define the long-term fate of this commercially and ecologically important predator. PMID:19075232

Demonstration of ion channel synthesis by isolated squid giant axon provides functional evidence for localized axonal membrane protein translation.

PubMed

Mathur, Chhavi; Johnson, Kory R; Tong, Brian A; Miranda, Pablo; Srikumar, Deepa; Basilio, Daniel; Latorre, Ramon; Bezanilla, Francisco; Holmgren, Miguel

2018-02-02

Local translation of membrane proteins in neuronal subcellular domains like soma, dendrites and axon termini is well-documented. In this study, we isolated the electrical signaling unit of an axon by dissecting giant axons from mature squids (Dosidicus gigas). Axoplasm extracted from these axons was found to contain ribosomal RNAs, ~8000 messenger RNA species, many encoding the translation machinery, membrane proteins, translocon and signal recognition particle (SRP) subunits, endomembrane-associated proteins, and unprecedented proportions of SRP RNA (~68% identical to human homolog). While these components support endoplasmic reticulum-dependent protein synthesis, functional assessment of a newly synthesized membrane protein in axolemma of an isolated axon is technically challenging. Ion channels are ideal proteins for this purpose because their functional dynamics can be directly evaluated by applying voltage clamp across the axon membrane. We delivered in vitro transcribed RNA encoding native or Drosophila voltage-activated Shaker K V channel into excised squid giant axons. We found that total K + currents increased in both cases; with added inactivation kinetics on those axons injected with RNA encoding the Shaker channel. These results provide unambiguous evidence that isolated axons can exhibit de novo synthesis, assembly and membrane incorporation of fully functional oligomeric membrane proteins.

Analysis of the Effects of Calcium or Magnesium on Voltage-Clamp Currents in Perfused Squid Axons Bathed in Solutions of High Potassium

PubMed Central

Rojas, Eduardo; Taylor, Robert E.; Atwater, Illani; Bezanilla, Francisco

1969-01-01

Isolated axons from the squid, Dosidicus gigas, were internally perfused with potassium fluoride solutions. Membrane currents were measured following step changes of membrane potential in a voltage-clamp arrangement with external isosmotic solution changes in the order: potassium-free artificial seawater; potassium chloride; potassium chloride containing 10, 25, 40 or 50, mM calcium or magnesium; and potassium-free artificial seawater. The following results suggest that the currents measured under voltage clamp with potassium outside and inside can be separated into two components and that one of them, the predominant one, is carried through the potassium system. (a) Outward currents in isosmotic potassium were strongly and reversibly reduced by tetraethylammonium chloride. (b) Without calcium or magnesium a progressive increase in the nontime-dependent component of the currents (leakage) occurred. (c) The restoration of calcium or magnesium within 15–30 min decreases this leakage. (d) With 50 mM divalent ions the steady-state current-voltage curve was nonlinear with negative resistance as observed in intact axons in isosmotic potassium. (e) The time-dependent components of the membrane currents were not clearly affected by calcium or magnesium. These results show a strong dependence of the leakage currents on external calcium or magnesium concentration but provide no support for the involvement of calcium or magnesium in the kinetics of the potassium system. PMID:5823216

Analysis of the effects of calcium or magnesium on voltage-clamp currents in perfused squid axons bathed in solutions of high potassium.

PubMed

Rojas, E; Taylor, R E; Atwater, I; Bezanilla, F

1969-10-01

Isolated axons from the squid, Dosidicus gigas, were internally perfused with potassium fluoride solutions. Membrane currents were measured following step changes of membrane potential in a voltage-clamp arrangement with external isosmotic solution changes in the order: potassium-free artificial seawater; potassium chloride; potassium chloride containing 10, 25, 40 or 50, mM calcium or magnesium; and potassium-free artificial seawater. The following results suggest that the currents measured under voltage clamp with potassium outside and inside can be separated into two components and that one of them, the predominant one, is carried through the potassium system. (a) Outward currents in isosmotic potassium were strongly and reversibly reduced by tetraethylammonium chloride. (b) Without calcium or magnesium a progressive increase in the nontime-dependent component of the currents (leakage) occurred. (c) The restoration of calcium or magnesium within 15-30 min decreases this leakage. (d) With 50 mM divalent ions the steady-state current-voltage curve was nonlinear with negative resistance as observed in intact axons in isosmotic potassium. (e) The time-dependent components of the membrane currents were not clearly affected by calcium or magnesium. These results show a strong dependence of the leakage currents on external calcium or magnesium concentration but provide no support for the involvement of calcium or magnesium in the kinetics of the potassium system.

Jumbo squid beaks: inspiration for design of robust organic composites.

PubMed

Miserez, Ali; Li, Youli; Waite, J Herbert; Zok, Frank

2007-01-01

The hard tissues found in some invertebrate marine organisms represent intriguing paradigms for robust, lightweight materials. The present study focuses on one such tissue: that comprising the beak of the jumbo squid (Dosidicus gigas). Its main constituents are chitin fibers (15-20wt.%) and histidine- and glycine-rich proteins (40-45%). Notably absent are mineral phases, metals and halogens. Despite being fully organic, beak hardness and stiffness are at least twice those of the most competitive synthetic organic materials (notably engineering polymers) and comparable to those of Glycera and Nereis jaws. Furthermore, the combination of hardness and stiffness makes the beaks more resistant to plastic deformation when in contact with blunt abrasives than virtually all metals and polymers. The 3,4-dihydroxy-l-phenylalanine and abundant histidine content in the beak proteins as well as the pigmented hydrolysis-resistant residue are suggestive of aromatic cross-linking. A high cross-linking density between the proteins and chitin may be the single most important determinant of hardness and stiffness in the beak. Beak microstructure is characterized by a lamellar arrangement of the constituents, with a weak interface that promotes crack deflection and endows the structure with high fracture toughness. The susceptibility of this microstructure to cracking along these interfaces from contact stresses at the external surface is mitigated by the presence of a protective coating.

Incorporation of liposomes containing squid tunic ACE-inhibitory peptides into fish gelatin.

PubMed

Mosquera, Mauricio; Giménez, Begoña; Montero, Pilar; Gómez-Guillén, Maria Carmen

2016-02-01

Hydrolysates from collagen of jumbo squid (Dosidicus gigas) tunics have shown excellent angiotensin I-converting enzyme (ACE)-inhibitory activity. However, peptides directly included in food systems may suffer a decrease in activity, which could be minimized by loading them into nanoliposomes. A fraction of peptides with molecular weights <1 kDa obtained from hydrolyzed squid tunics, with reasonably high ACE-inhibitory activity (half-maximal inhibitory concentration IC50 = 0.096 g L(-1)), was encapsulated in phosphatidylcholine nanoliposomes. The peptide concentration affected the encapsulation efficiency and the stability of the resulting liposomes, which remained with a high zeta potential value (-54.3 mV) for at least 1 week at the most suitable peptide concentration. The optimal peptide concentration was established as 1.75 g L(-1). Liposomes obtained with this peptide concentration showed an encapsulation efficiency of 53%, a zeta potential of -59 mV, an average diameter of 70.3 nm and proved to be stable in the pH range 3-7 at 4 °C. Liposomes containing ACE-inhibitory peptides were incorporated in fish gelatin without detriment to the rheological properties and thermal stability of the resulting cold-induced gel. The ACE-inhibitory activity of the peptide fraction, which was not affected by the encapsulation process, conferred the bioactive potential to the nanoliposome-containing gelatin gel. © 2015 Society of Chemical Industry.

Ionic channels and nerve membrane constituents. Tetrodotoxin-like interaction of saxitoxin with cholesterol monolayers.

PubMed

Villegas, R; Barnola, F V

1972-01-01

Saxitoxin (STX) and tetrodotoxin (TTX) have the same striking property of blocking the Na(+) channels in the axolemma. Experiments with nerve plasma membrane components of the squid Dosidicus gigas have shown that TTX interacts with cholesterol monolayers. Similar experiments were carried out with STX. The effect of STX on the surface pressure-area diagrams of lipid monolayers and on the fluorescence emission spectra of sonicated nerve membranes was studied. The results indicate a TTX-like interaction of STX with cholesterol monolayers. The expansion of the monolayers caused by 10(-6)M STX was 2.2 A(2)/cholesterol molecule at 25 degrees C. From surface pressure measurements at constant cholesterol area (39 A(2)/molecule) in media with various STX concentrations, it was calculated that the STX/cholesterol surface concentration ratio is 0.54. The apparent dissociation constant of the STX-cholesterol monolayer complex is 4.0 x 10(-7)M. The STX/cholesterol ratio and the apparent dissociation constant are similar to those determined for TTX. The presence of other lipids in the monolayers affects the STX-cholesterol association. The interactions of STX and TTX with cholesterol monolayers suggest (a) that cholesterol molecules may be part of the nerve membrane Na(+) channels, or (b) that the toxin receptor at the nerve membrane shares similar chemical features with the cholesterol monolayers.

[Biochemistry and functional characterization of squid mantle meat (Dosidicus gigas)].

PubMed

Abugoch, L; Guarda, A; María Pérez, L; Isabel Donghi, M

2000-12-01

A study for the characterization of frozen giant squid mantle (meat) protein stored at -25 degrees C for 8 month was started. In the present research, the following functional properties were investigate: emulsifying, water holding and gel forming capacities. Optimal conditions for the separation and differentiation of miofibrillar and sarcoplasmatic proteins were also studied. It was found that the unfrozen giant squid mantle meat es capable of emulifying 2.817,4 g of oil/g of protein and holding capacity was 3.64 g of water/g of protein. Related to the gel forming capacity, it was not obtain, probably due to excessive storage of the meat. With regard to miofibrilar protein obtention of the squid mantle meat, it was found that two low ionic strength washings (I = 0.05), the sarcoplasmic proteins were practically eliminated from the protein matrix. The differentiation of miofibrilar and sarcoplasmatic proteins was obtained by PAGE-SDS of the squid mantle meat extracted at two different ionic strength (I = 0.05 and I = 0.5). This work demonstrates that the giant squid mantle protein has a high emulsifying and water holding capacity, and it can be used, as a raw material, for the improvement of sausage products. About the gelling products, more studies will be necessary with fresh squid mantle meat to conclude about this functional property.

Vestigial phragmocone in the gladius points to a deepwater origin of squid (Mollusca: Cephalopoda)

NASA Astrophysics Data System (ADS)

Arkhipkin, Alexander I.; Bizikov, Vyacheslav A.; Fuchs, Dirk

2012-03-01

The microstructure of the gladius cone was investigated in six species of nektonic squid: shallow-water Loligo gahi (Loliginidae), pelagic eurybathic Illex argentinus, Todarodes pacificus, Dosidicus gigas (Ommastrephidae), and deepwater Onykia ingens (Onychoteuthidae) and Gonatus antarcticus (Gonatidae) using state-of-the-art microscopy. Apart from L. gahi, all other species had septa-like layers in the gladius cone, which for the first time were investigated in detail and compared with those in extinct Cretaceous belemnites Hibolithes sp. and Pachyteuthis sp., and spirulid Cyrtobelus sp. It was found that the organic layers of the gladius cone in recent squid can be homologized with the organic components of the shell in fossil phragmocone-bearing coleoids. The septa-like layers in modern gladius cones therefore represent a vestigial phragmocone composed of organic septal rudiments of the ancestral phragmocone that has lost the siphuncle and gas-filled chambers. The well-developed rostrum in onychoteuthids and small rostrum of the gladius in ommastrephids and gonatids can be seen as homologous with the belemnoid rostrum, which may indicate a close phylogenetic relationship between belemnites and at least some squid. Possible evolutionary pathways of the reduction of the functional phragmocone in squid ancestors are discussed. Several features such as the loss of shell calcification, deep water speciation, and the structure of the equilibrium organ point to a deep-water origin of squids.

Extreme plasticity in life-history strategy allows a migratory predator (jumbo squid) to cope with a changing climate.

PubMed

Hoving, Henk-Jan T; Gilly, William F; Markaida, Unai; Benoit-Bird, Kelly J; -Brown, Zachary W; Daniel, Patrick; Field, John C; Parassenti, Liz; Liu, Bilin; Campos, Bernardita

2013-07-01

Dosidicus gigas (jumbo or Humboldt squid) is a semelparous, major predator of the eastern Pacific that is ecologically and commercially important. In the Gulf of California, these animals mature at large size (>55 cm mantle length) in 1-1.5 years and have supported a major commercial fishery in the Guaymas Basin during the last 20 years. An El Niño event in 2009-2010, was accompanied by a collapse of this fishery, and squid in the region showed major changes in the distribution and life-history strategy. Large squid abandoned seasonal coastal-shelf habitats in 2010 and instead were found in the Salsipuedes Basin to the north, an area buffered from the effects of El Niño by tidal upwelling and a well-mixed water column. The commercial fishery also relocated to this region. Although large squid were not found in the Guaymas Basin from 2010 to 2012, small squid were abundant and matured at an unusually small mantle-length (<30 cm) and young age (approximately 6 months). Juvenile squid thus appeared to respond to El Niño with an alternative life-history trajectory in which gigantism and high fecundity in normally productive coastal-shelf habitats were traded for accelerated reproduction at small size in an offshore environment. Both small and large mature squid, were present in the Salsipuedes Basin during 2011, indicating that both life- history strategies can coexist. Hydro-acoustic data, reveal that squid biomass in this study area nearly doubled between 2010 and 2011, primarily due to a large increase in small squid that were not susceptible to the fishery. Such a climate-driven switch in size-at-maturity may allow D. gigas to rapidly adapt to and cope with El Niño. This ability is likely to be an important factor in conjunction with longerterm climate-change and the potential ecological impacts of this invasive predator on marine ecosystems. © 2013 Blackwell Publishing Ltd.

Energy landscape of the reactions governing the Na+ deeply occluded state of the Na+/K+-ATPase in the giant axon of the Humboldt squid

PubMed Central

Castillo, Juan P.; De Giorgis, Daniela; Basilio, Daniel; Gadsby, David C.; Rosenthal, Joshua J. C.; Latorre, Ramon; Holmgren, Miguel; Bezanilla, Francisco

2011-01-01

The Na+/K+ pump is a nearly ubiquitous membrane protein in animal cells that uses the free energy of ATP hydrolysis to alternatively export 3Na+ from the cell and import 2K+ per cycle. This exchange of ions produces a steady-state outwardly directed current, which is proportional in magnitude to the turnover rate. Under certain ionic conditions, a sudden voltage jump generates temporally distinct transient currents mediated by the Na+/K+ pump that represent the kinetics of extracellular Na+ binding/release and Na+ occlusion/deocclusion transitions. For many years, these events have escaped a proper thermodynamic treatment due to the relatively small electrical signal. Here, taking the advantages offered by the large diameter of the axons from the squid Dosidicus gigas, we have been able to separate the kinetic components of the transient currents in an extended temperature range and thus characterize the energetic landscape of the pump cycle and those transitions associated with the extracellular release of the first Na+ from the deeply occluded state. Occlusion/deocclusion transition involves large changes in enthalpy and entropy as the ion is exposed to the external milieu for release. Binding/unbinding is substantially less costly, yet larger than predicted for the energetic cost of an ion diffusing through a permeation pathway, which suggests that ion binding/unbinding must involve amino acid side-chain rearrangements at the site. PMID:22143771

Biomagnification of mercury and its antagonistic interaction with selenium in yellowfin tuna Thunnus albacares in the trophic web of Baja California Sur, Mexico.

PubMed

Ordiano-Flores, Alfredo; Rosíles-Martínez, Rene; Galván-Magaña, Felipe

2012-12-01

Mercury and selenium concentrations were determined in muscle of 37 yellowfin tuna (Thunnus albacares) captured aboard of Mexican purse-seiners boats off western coast of Baja California Sur, between Punta Eugenia and Cabo Falso, from October to December 2006. Also, its prey (mainly, jumbo squid Dosidicus gigas and pelagic red crab Pleuroncodes planipes) were analyzed from the stomach contents. All the mercury values obtained were lower that mercury content recommended by standard legal limits for seafood adopted by Mexican norms (typically 0.5-1.0μg g(-1)). Mercury concentrations vary between 0.06 and 0.51μg g(-1) in yellowfin tuna, and from 0.01 to 0.20μg g(-1) in its prey, suggesting that mercury can accumulate in prey tissues and that of their predator. Biomagnification factors (BMF) between predator-prey associations were calculated. The BMFs were >1, indicating that mercury biomagnifies along the food web of yellowfin tuna. In all species studied there was a molar excess of selenium over mercury. The rank order of mean selenium/mercury molar ratios was for pufferfish (42.62)> diamond squid (15.09)>yellowfin tuna (10.29)>pelagic red crab (10.05)>panama lightfish (9.54)> jumbo squid (8.91). The selenium health benefit value (Se-HBV) was calculated to have an improved understanding of the health benefits and risk of fish consumption. Copyright © 2012 Elsevier Inc. All rights reserved.

Energy landscape of the reactions governing the Na+ deeply occluded state of the Na+/K+-ATPase in the giant axon of the Humboldt squid.

PubMed

Castillo, Juan P; De Giorgis, Daniela; Basilio, Daniel; Gadsby, David C; Rosenthal, Joshua J C; Latorre, Ramon; Holmgren, Miguel; Bezanilla, Francisco

2011-12-20

The Na(+)/K(+) pump is a nearly ubiquitous membrane protein in animal cells that uses the free energy of ATP hydrolysis to alternatively export 3Na(+) from the cell and import 2K(+) per cycle. This exchange of ions produces a steady-state outwardly directed current, which is proportional in magnitude to the turnover rate. Under certain ionic conditions, a sudden voltage jump generates temporally distinct transient currents mediated by the Na(+)/K(+) pump that represent the kinetics of extracellular Na(+) binding/release and Na(+) occlusion/deocclusion transitions. For many years, these events have escaped a proper thermodynamic treatment due to the relatively small electrical signal. Here, taking the advantages offered by the large diameter of the axons from the squid Dosidicus gigas, we have been able to separate the kinetic components of the transient currents in an extended temperature range and thus characterize the energetic landscape of the pump cycle and those transitions associated with the extracellular release of the first Na(+) from the deeply occluded state. Occlusion/deocclusion transition involves large changes in enthalpy and entropy as the ion is exposed to the external milieu for release. Binding/unbinding is substantially less costly, yet larger than predicted for the energetic cost of an ion diffusing through a permeation pathway, which suggests that ion binding/unbinding must involve amino acid side-chain rearrangements at the site.

Aperture effects in squid jet propulsion.

PubMed

Staaf, Danna J; Gilly, William F; Denny, Mark W

2014-05-01

Squid are the largest jet propellers in nature as adults, but as paralarvae they are some of the smallest, faced with the inherent inefficiency of jet propulsion at a low Reynolds number. In this study we describe the behavior and kinematics of locomotion in 1 mm paralarvae of Dosidicus gigas, the smallest squid yet studied. They swim with hop-and-sink behavior and can engage in fast jets by reducing the size of the mantle aperture during the contraction phase of a jetting cycle. We go on to explore the general effects of a variable mantle and funnel aperture in a theoretical model of jet propulsion scaled from the smallest (1 mm mantle length) to the largest (3 m) squid. Aperture reduction during mantle contraction increases propulsive efficiency at all squid sizes, although 1 mm squid still suffer from low efficiency (20%) because of a limited speed of contraction. Efficiency increases to a peak of 40% for 1 cm squid, then slowly declines. Squid larger than 6 cm must either reduce contraction speed or increase aperture size to maintain stress within maximal muscle tolerance. Ecological pressure to maintain maximum velocity may lead them to increase aperture size, which reduces efficiency. This effect might be ameliorated by nonaxial flow during the refill phase of the cycle. Our model's predictions highlight areas for future empirical work, and emphasize the existence of complex behavioral options for maximizing efficiency at both very small and large sizes.

Shark predation on cephalopods in the Mexican and Ecuadorian Pacific Ocean

NASA Astrophysics Data System (ADS)

Galván-Magaña, Felipe; Polo-Silva, Carlos; Berenice Hernández-Aguilar, Sandra; Sandoval-Londoño, Alejandro; Ruth Ochoa-Díaz, Maria; Aguilar-Castro, Nallely; Castañeda-Suárez, David; Cabrera Chavez-Costa, Alejandra; Baigorrí-Santacruz, Álvaro; Eden Torres-Rojas, Yassir; Andrés Abitia-Cárdenas, Leonardo

2013-10-01

Pelagic predators such as sharks have been shown to be effective cephalopod samplers, because they have high consumption rates and swimming speeds. The stomach contents of these predators allow us to determine the distribution and abundance of cephalopods, considering the scarcity of biological information and the difficulty of catching squids and octopi using traditional methods. The silky shark (Carcharhinus falciformis), blue shark (Prionace glauca), scalloped hammerhead (Sphyrna lewini), smooth hammerhead (Sphyrna zygaena), pelagic thresher shark (Alopias pelagicus), and bigeye thresher shark (Alopias superciliosus) were caught off both coasts of Baja California Sur, Mexico, and in the Ecuadorian Pacific Ocean. Cephalopod sizes (mantle lengths, ML) were calculated based on the beak measurements to determine the size of cephalopods consumed by the sharks. We identified 21 cephalopod species based on beak items found in the shark stomachs. The most abundant cephalopods consumed by sharks in both areas were Dosidicus gigas, Ancistrocheirus lesueurii, Onychoteuthis banksii, Sthenoteuthis ovalaniensis, Argonauta spp., Abraliopsis affinis, and Mastigoteuthis dentata. The cephalopod's habitat provides information about the depth at which these sharks capture their prey. The blue shark feeds on cephalopods in epipelagic, mesopelagic, and bathypelagic waters; the silky shark feeds on cephalopods in epipelagic waters; and the scalloped hammerhead shark preys on cephalopods in neritic (bottom) and oceanic waters (epipelagic and mesopelagic). The pelagic thresher shark consumed epipelagic and neritic species; whereas the bigeye thresher shark feeds mainly on epipelagic and mesopelagic squids in Ecuadorian waters. The smooth hammerhead preys on epipelagic and mesopelagic squids off Mexico and Ecuador.

The role of water on the structure and mechanical properties of a thermoplastic natural block co-polymer from squid sucker ring teeth.

PubMed

Rieu, Clément; Bertinetti, Luca; Schuetz, Roman; Salinas-Zavala, Cesar Ca; Weaver, James C; Fratzl, Peter; Miserez, Ali; Masic, Admir

2016-09-02

Hard biological polymers exhibiting a truly thermoplastic behavior that can maintain their structural properties after processing are extremely rare and highly desirable for use in advanced technological applications such as 3D-printing, biodegradable plastics and robust composites. One exception are the thermoplastic proteins that comprise the sucker ring teeth (SRT) of the Humboldt jumbo squid (Dosidicus gigas). In this work, we explore the mechanical properties of reconstituted SRT proteins and demonstrate that the material can be re-shaped by simple processing in water and at relatively low temperature (below 100 °C). The post-processed material maintains a high modulus in the GPa range, both in the dry and the wet states. When transitioning from low to high humidity, the material properties change from brittle to ductile with an increase in plastic deformation, where water acts as a plasticizer. Using synchrotron x-ray scattering tools, we found that water mostly influences nano scale structure, whereas at the molecular level, the protein structure remains largely unaffected. Furthermore, through simultaneous in situ x-ray scattering and mechanical tests, we show that the supramolecular network of the reconstituted SRT material exhibits a progressive alignment along the strain direction, which is attributed to chain alignment of the amorphous domains of SRT proteins. The high modulus in both dry and wet states, combined with their efficient thermal processing characteristics, make the SRT proteins promising substitutes for applications traditionally reserved for petroleum-based thermoplastics.

Effects of mesoscale structures on the distribution of cephalopod paralarvae in the Gulf of California and adjacent Pacific

NASA Astrophysics Data System (ADS)

Ruvalcaba-Aroche, Erick D.; Sánchez-Velasco, Laura; Beier, Emilio; Godínez, Victor M.; Barton, Eric D.; Pacheco, Ma. Rocío

2018-01-01

Vertical distribution of the cephalopod paralarvae was investigated in relation to a system of two cyclonic and three anticyclonic eddies in the southern Gulf of California and a front in the adjacent Pacific Ocean. Results showed that the preferential habitat for the Sthenoteuthis oualaniensis - Dosidicus gigas "SD-complex" in both regions was the oxygenated surface mixed layer and the thermocline. The highest abundances occurred in of one of the anticyclonic eddies and a frontal zone, which are convergent structures. Enoploteuthid and Pyroteuthid paralarvae both displayed their highest abundances in the thermocline. Pyroteuthids dominated in the cyclonic eddy whereas Enoploteuthidae were less evident in the eddy system. Pyroteuthids were observed on the western (California Current) side of the frontal zone, and Enoploteuthids on its eastern (Gulf of California) side. The octopods and the complex of Ommastrephes-Eucleoteuthis-Hyaloteuthis paralarvae were present below the thermocline. Both groups had a scarce presence in the eddy system and high abundance near the frontal zone. The octopods abounded on the eastern side in association with the low dissolved oxygen concentrations (< 44 μmol kg-1) of Subtropical-Subsurface Water; the complex on the western front side was immersed in California Current Water. It may be concluded that the spawning and early stages of development of these cephalopod groups are associated with particular mesoscale structures of the water masses. For example, the "SD complex" inhabits the surface water masses, preferentially in convergence zones generated by mesoscale activity.

Ventilation rates and activity levels of juvenile jumbo squid under metabolic suppression in the oxygen minimum zone.

PubMed

Trübenbach, Katja; Pegado, Maria R; Seibel, Brad A; Rosa, Rui

2013-02-01

The Humboldt (jumbo) squid, Dosidicus gigas, is a part-time resident of the permanent oxygen minimum zone (OMZ) in the Eastern Tropical Pacific and, thereby, it encounters oxygen levels below its critical oxygen partial pressure. To better understand the ventilatory mechanisms that accompany the process of metabolic suppression in these top oceanic predators, we exposed juvenile D. gigas to the oxygen levels found in the OMZ (1% O(2), 1 kPa, 10 °C) and measured metabolic rate, activity cycling patterns, swimming mode, escape jet (burst) frequency, mantle contraction frequency and strength, stroke volume and oxygen extraction efficiency. In normoxia, metabolic rate varied between 14 and 29 μmol O(2) g(-1) wet mass h(-1), depending on the level of activity. The mantle contraction frequency and strength were linearly correlated and increased significantly with activity level. Additionally, an increase in stroke volume and ventilatory volume per minute was observed, followed by a mantle hyperinflation process during high activity periods. Squid metabolic rate dropped more than 75% during exposure to hypoxia. Maximum metabolic rate was not achieved under such conditions and the metabolic scope was significantly decreased. Hypoxia changed the relationship between mantle contraction strength and frequency from linear to polynomial with increasing activity, indicating that, under hypoxic conditions, the jumbo squid primarily increases the strength of mantle contraction and does not regulate its frequency. Under hypoxia, jumbo squid also showed a larger inflation period (reduced contraction frequency) and decreased relaxed mantle diameter (shortened diffusion pathway), which optimize oxygen extraction efficiency (up to 82%/34%, without/with consideration of 60% potential skin respiration). Additionally, they breathe 'deeply', with more powerful contractions and enhanced stroke volume. This deep-breathing behavior allows them to display a stable ventilatory volume per minute, and explains the maintenance of the squid's cycling activity under such O(2) conditions. During hypoxia, the respiratory cycles were shorter in length but increased in frequency. This was accompanied by an increase in the number of escape jets during active periods and a faster switch between swimming modes. In late hypoxia (onset ~170 ± 10 min), all the ventilatory processes were significantly reduced and followed by a lethargic state, a behavior that seems closely associated with the process of metabolic suppression and enables the squid to extend its residence time in the OMZ.

Ionic channels and nerve membrane lipids. Cholesterol-tetrodotoxin interaction.

PubMed

Villegas, R; Barnola, F V; Camejo, G

1970-04-01

Experiments were carried out to investigate possible interactions of tetrodotoxin (TTX) with lipid molecules isolated from nerve fiber plasma membranes of the squid Dosidicus gigas. TTX has a highly selective ability to block the channel normally used by Na(+) to cross the axolemma during nervous impulse conduction. In order to investigate the interaction each lipid sample was spread on 5 x 10(-7)M TTX and TTX-free 0.15 M NaCl solutions adjusted to pH 7.4 with 7 x 10(-3)M phosphate buffer. The surface pressure-area diagrams of the lipid monolayers revealed that TTX interacts only with cholesterol. The expansion of the cholesterol monolayers at 5 x 10(-7)M TTX was 2 A(2)/molecule at zero pressure for the experiments at 20 degrees C and 2.5 A(2)/molecule for those at 25 degrees C. Similar results were obtained in KCl subphases. The apparent dissociation constant of the cholesterol-TTX complex calculated from dose-response experiments is 2.6 x 10(-7)M. Experiments at pH 10.1 revealed that the zwitter ionic form of TTX is less active. Experiments with cholesterol derivatives (cholesteryl acetate, cholesterol methyl ether, cholestanol, and cholestanyl acetate) indicate that for the interaction with TTX a partial negatively charged group at C-3 and a double bond between C-5 and C-6 on the steroid nucleus are required. Tetrodonic acid, a biologically inactive derivative of TTX, does not interact with cholesterol. The results lead us to propose that cholesterol is part of the Na(+) channel.

Ionic Channels and Nerve Membrane Lipids Cholesterol-tetrodotoxin interaction

PubMed Central

Villegas, Raimundo; Barnola, Flor V.; Camejo, Germáan

1970-01-01

Experiments were carried out to investigate possible interactions of tetrodotoxin (TTX) with lipid molecules isolated from nerve fiber plasma membranes of the squid Dosidicus gigas. TTX has a highly selective ability to block the channel normally used by Na+ to cross the axolemma during nervous impulse conduction. In order to investigate the interaction each lipid sample was spread on 5 x 10-7 M TTX and TTX-free 0.15 M NaCl solutions adjusted to pH 7.4 with 7 x 10-3 M phosphate buffer. The surface pressure-area diagrams of the lipid monolayers revealed that TTX interacts only with cholesterol. The expansion of the cholesterol monolayers at 5 x 10-7 M TTX was 2 A2/molecule at zero pressure for the experiments at 20°C and 2.5 A2/molecule for those at 25°C. Similar results were obtained in KCl subphases. The apparent dissociation constant of the cholesterol-TTX complex calculated from dose-response experiments is 2.6 x 10-7 M. Experiments at pH 10.1 revealed that the zwitter ionic form of TTX is less active. Experiments with cholesterol derivatives (cholesteryl acetate, cholesterol methyl ether, cholestanol, and cholestanyl acetate) indicate that for the interaction with TTX a partial negatively charged group at C-3 and a double bond between C-5 and C-6 on the steroid nucleus are required. Tetrodonic acid, a biologically inactive derivative of TTX, does not interact with cholesterol. The results lead us to propose that cholesterol is part of the Na+ channel. PMID:5435784

Filtration coefficient of the axon membrane as measured with hydrostatic and osmotic methods.

PubMed

Vargas, F F

1968-01-01

The hydraulic conductivity of the membranes surrounding the giant axon of the squid, Dosidicus gigas, was measured. In some axons the axoplasm was partially removed by suction. Perfusion was then established by insertion of a second pipette. In other axons the axoplasm was left intact and only one pipette was inserted. In both groups hydrostatic pressure was applied by means of a water column in a capillary manometer. Displacement of the meniscus in time gave the rate of fluid flowing across the axon sheath. In both groups osmotic differences across the membrane were established by the addition of a test molecule to the external medium which was seawater. The hydraulic conductivity determined by application of hydrostatic pressure was 10.6 +/- 0.8.10(-8) cm/sec cm H(2)O in perfused axons and 3.2 +/- 0.6.10(-8) cm/sec cm H(2)O in intact axons. When the driving force was an osmotic pressure gradient the conductivity was 4.5 +/- 0.6 x 10(-10) cm/sec cm H(2)O and 4.8 +/- 0.9 x 10(-10) cm/sec cm H(2)O in perfused and intact axons, respectively. A comparable result was found when the internal solution was made hyperosmotic. The fluid flow was a linear function of the hydrostatic pressure up to 70 cm of water. Glycerol outflux and membrane conductance were increased 1.6 and 1.1 times by the application of hydrostatic pressure. These increments do not give an explanation of the difference between the filtration coefficients. Other possible explanations are suggested and discussed.

The impact of overfishing and El Niño on the condition factor and reproductive success of Peruvian hake, Merluccius gayi peruanus

NASA Astrophysics Data System (ADS)

Ballón, Michael; Wosnitza-Mendo, Claudia; Guevara-Carrasco, Renato; Bertrand, Arnaud

2008-10-01

In this study we examine physiological responses of Peruvian hake ( Merluccius gayi peruanus) to changes in their population structure and physical environment during the period 1971-2004. In particular, we assess the relative investment of energy in growth and/or reproduction of small (20-35 cm) and large (35-50 cm) hake. We calculated the (i) condition (Fulton’s K), (ii) gonad and (iii) gut fullness indices for 42,761 female hakes sampled from commercial landings; these indices indicate fish somatic, reproductive and feeding condition, respectively. Using Generalized Additive Models we then examined potential relationships between these indices and sea surface temperature anomalies and date. Drastic energy exhaustion and a decrease in female hake fecundity were observed during El Niño events. The long-term trend showed a general increase in condition factor and a decrease in gonad index for large hake between 1971 and 2004. Small hake exhibited a different trend with an increase in reproductive activity, which was accompanied by an earlier maturation. We hypothesise that the observed low investment of energy in reproduction by large female hake might be related to the lack of large males, due to a sex-selective fishery and the impact of El Niño. We suggest that fishing diminished hake reproductive capacity, modified the sex ratio in favour of females and increased population vulnerability to environmental stress, in particular to the El Niño. The impact of multidecadal variability and predators like the squid, Dosidicus gigas, remain unresolved until longer time series become available.

GigaDB: announcing the GigaScience database.

PubMed

Sneddon, Tam P; Li, Peter; Edmunds, Scott C

2012-07-12

With the launch of GigaScience journal, here we provide insight into the accompanying database GigaDB, which allows the integration of manuscript publication with supporting data and tools. Reinforcing and upholding GigaScience's goals to promote open-data and reproducibility of research, GigaDB also aims to provide a home, when a suitable public repository does not exist, for the supporting data or tools featured in the journal and beyond.

GigaDB: announcing the GigaScience database

PubMed Central

2012-01-01

With the launch of GigaScience journal, here we provide insight into the accompanying database GigaDB, which allows the integration of manuscript publication with supporting data and tools. Reinforcing and upholding GigaScience’s goals to promote open-data and reproducibility of research, GigaDB also aims to provide a home, when a suitable public repository does not exist, for the supporting data or tools featured in the journal and beyond. PMID:23587345

Filtration Coefficient of the Axon Membrane As Measured with Hydrostatic and Osmotic Methods

PubMed Central

Vargas, Fernando F.

1968-01-01

The hydraulic conductivity of the membranes surrounding the giant axon of the squid, Dosidicus gigas, was measured. In some axons the axoplasm was partially removed by suction. Perfusion was then established by insertion of a second pipette. In other axons the axoplasm was left intact and only one pipette was inserted. In both groups hydrostatic pressure was applied by means of a water column in a capillary manometer. Displacement of the meniscus in time gave the rate of fluid flowing across the axon sheath. In both groups osmotic differences across the membrane were established by the addition of a test molecule to the external medium which was seawater. The hydraulic conductivity determined by application of hydrostatic pressure was 10.6 ± 0.8.10-8 cm/sec cm H2O in perfused axons and 3.2 ± 0.6.10-8 cm/sec cm H2O in intact axons. When the driving force was an osmotic pressure gradient the conductivity was 4.5 ± 0.6 x 10-10 cm/sec cm H2O and 4.8 ± 0.9 x 10-10 cm/sec cm H2O in perfused and intact axons, respectively. A comparable result was found when the internal solution was made hyperosmotic. The fluid flow was a linear function of the hydrostatic pressure up to 70 cm of water. Glycerol outflux and membrane conductance were increased 1.6 and 1.1 times by the application of hydrostatic pressure. These increments do not give an explanation of the difference between the filtration coefficients. Other possible explanations are suggested and discussed. PMID:5642470

Impact of the structural differences between α- and β-chitosan on their depolymerizing reaction and antibacterial activity.

PubMed

Jung, Jooyeoun; Zhao, Yanyun

2013-09-18

The polymeric structure characteristics of β-chitosan from jumbo squid (Dosidicus gigas) pens and α-chitosan from shrimp shells during depolymerization by cellulase hydrolysis at different degrees of deacetylation (DDA) (60, 75, and 90%) were investigated by using Fourier transform infrared spectroscopy and X-ray diffraction. Antibacterial activity of β-chitosan against Escherichia coli and Listeria innocua was compared with that of α-chitosan at similar Mw and degrees of deacetylation (DDA) by studying inhibition ratio and minimal inhibition concentration (MIC) and was coordinated with the structural characteristics of the two forms of chitosan. β-Chitosan was more reactive to cellulase hydrolysis than α-chitosan due to its relatively lower crystallinity (CI) and loose crystal property, and the 75% DDA chitosan was more susceptible to cellulase than the 90% DDA ones with the 75% DDA of β-chitosan mostly reactive. Both forms of chitosan showed more inhibition against E. coli than against L. innocua, and no difference against L. innocua between the two forms of chitosan was observed. However, the two forms of chitosan exhibited different levels of antibacterial activity against E. coli, in which 75% DDA/31 kDa β-chitosan demonstrated significantly higher inhibition (lower MIC) than that of 75% DDA/31 kDa α-chitosan, whereas 90% DDA/74-76 kDa α-chitosan had a higher inhibition ratio than that of 90% DDA/74-76 kDa of β-chitosan. This result may be explained by the impact of the different structural properties between α- and β-chitosan on chitosan conformations in the solution. This study provided new information about the biological activities of β-chitosan, a bioactive compound with unique functionalities and great potential for food and other applications.

A Glycoprotein in Shells of Conspecifics Induces Larval Settlement of the Pacific Oyster Crassostrea gigas

PubMed Central

Vasquez, Hebert Ely; Hashimoto, Kyotaro; Yoshida, Asami; Hara, Kenji; Imai, Chisato Chris; Kitamura, Hitoshi; Satuito, Cyril Glenn

2013-01-01

Settlement of larvae of Crassostrea gigas on shell chips (SC) prepared from shells of 11 different species of mollusks was investigated. Furthermore, the settlement inducing compound in the shell of C. gigas was extracted and subjected to various treatments to characterize the chemical cue. C. gigas larvae settled on SC of all species tested except on Patinopecten yessoensis and Atrina pinnata. In SC of species that induced C. gigas larvae to settle, settlement was proportionate to the amount of SC supplied to the larvae. When compared to C. gigas SC, all species except Crassostrea nippona showed lower settlement inducing activities, suggesting that the cue may be more abundant or in a more available form to the larvae in shells of conspecific and C. nippona than in other species. The settlement inducing activity of C. gigas SC remained intact after antibiotic treatment. Extraction of C. gigas SC with diethyl ether (Et2O-ex), ethanol (EtOH-ex), and water (Aq-ex) did not induce larval settlement of C. gigas larvae. However, extraction of C. gigas SC with 2N of hydrochloric acid (HCl-ex) induced larval settlement that was at the same level as the SC. The settlement inducing compound in the HCl-ex was stable at 100°C but was destroyed or degraded after pepsin, trypsin, PNGase F and trifluoromethanesulfonic acid treatments. This chemical cue eluted between the molecular mass range of 45 and 150 kDa after gel filtration and revealed a major band at 55 kDa on the SDS-PAGE gel after staining with Stains-all. Thus, a 55 kDa glycoprotein component in the organic matrix of C. gigas shells is hypothesized to be the chemical basis of larval settlement on conspecifics. PMID:24349261

GigaTON: an extensive publicly searchable database providing a new reference transcriptome in the pacific oyster Crassostrea gigas.

PubMed

Riviere, Guillaume; Klopp, Christophe; Ibouniyamine, Nabihoudine; Huvet, Arnaud; Boudry, Pierre; Favrel, Pascal

2015-12-02

The Pacific oyster, Crassostrea gigas, is one of the most important aquaculture shellfish resources worldwide. Important efforts have been undertaken towards a better knowledge of its genome and transcriptome, which makes now C. gigas becoming a model organism among lophotrochozoans, the under-described sister clade of ecdysozoans within protostomes. These massive sequencing efforts offer the opportunity to assemble gene expression data and make such resource accessible and exploitable for the scientific community. Therefore, we undertook this assembly into an up-to-date publicly available transcriptome database: the GigaTON (Gigas TranscriptOme pipeliNe) database. We assembled 2204 million sequences obtained from 114 publicly available RNA-seq libraries that were realized using all embryo-larval development stages, adult organs, different environmental stressors including heavy metals, temperature, salinity and exposure to air, which were mostly performed as part of the Crassostrea gigas genome project. This data was analyzed in silico and resulted into 56621 newly assembled contigs that were deposited into a publicly available database, the GigaTON database. This database also provides powerful and user-friendly request tools to browse and retrieve information about annotation, expression level, UTRs, splice and polymorphism, and gene ontology associated to all the contigs into each, and between all libraries. The GigaTON database provides a convenient, potent and versatile interface to browse, retrieve, confront and compare massive transcriptomic information in an extensive range of conditions, tissues and developmental stages in Crassostrea gigas. To our knowledge, the GigaTON database constitutes the most extensive transcriptomic database to date in marine invertebrates, thereby a new reference transcriptome in the oyster, a highly valuable resource to physiologists and evolutionary biologists.

Heterologous expression of the Desulfovibrio gigas [NiFe] hydrogenase in Desulfovibrio fructosovorans MR400.

PubMed

Rousset, M; Magro, V; Forget, N; Guigliarelli, B; Belaich, J P; Hatchikian, E C

1998-09-01

The ability of Desulfovibrio fructosovorans MR400 DeltahynABC to express the heterologous cloned [NiFe] hydrogenase of Desulfovibrio gigas was investigated. The [NiFe] hydrogenase operon from D. gigas, hynABCD, was cloned, sequenced, and introduced into D. fructosovorans MR400. A portion of the recombinant heterologous [NiFe] hydrogenase was totally matured, exhibiting catalytic and spectroscopic properties identical to those of the native D. gigas protein. A chimeric operon containing hynAB from D. gigas and hynC from D. fructosovorans placed under the control of the D. fructosovorans hynAp promoter was constructed and expressed in D. fructosovorans MR400. Under these conditions, the same level of activity was obtained as with the D. gigas hydrogenase operon.

Heterologous Expression of the Desulfovibrio gigas [NiFe] Hydrogenase in Desulfovibrio fructosovorans MR400

PubMed Central

Rousset, Marc; Magro, Valérie; Forget, Nicole; Guigliarelli, Bruno; Belaich, Jean-Pierre; Hatchikian, E. Claude

1998-01-01

The ability of Desulfovibrio fructosovorans MR400 ΔhynABC to express the heterologous cloned [NiFe] hydrogenase of Desulfovibrio gigas was investigated. The [NiFe] hydrogenase operon from D. gigas, hynABCD, was cloned, sequenced, and introduced into D. fructosovorans MR400. A portion of the recombinant heterologous [NiFe] hydrogenase was totally matured, exhibiting catalytic and spectroscopic properties identical to those of the native D. gigas protein. A chimeric operon containing hynAB from D. gigas and hynC from D. fructosovorans placed under the control of the D. fructosovorans hynAp promoter was constructed and expressed in D. fructosovorans MR400. Under these conditions, the same level of activity was obtained as with the D. gigas hydrogenase operon. PMID:9733707

Limited impact of an invasive oyster on intertidal assemblage structure and biodiversity: the importance of environmental context and functional equivalency with native species.

PubMed

Zwerschke, Nadescha; Hollyman, Philip R; Wild, Romy; Strigner, Robin; Turner, John R; King, Jonathan W

2018-01-01

Impacts of invasive species are context dependent and linked to the ecosystem they occur within. To broaden the understanding of the impact of a globally widespread invasive oyster, Crassostrea ( Magallana ) gigas, intertidal surveys were carried out at 15 different sites in Europe. The impact of C. gigas on macro- (taxa surrounding oyster > 1 cm) and epifaunal (taxa on oyster < 1 cm) benthic communities and α and β-diversity was assessed and compared to those associated with native ecosystem engineers, including the flat oyster Ostrea edulis . Whilst the effect of C. gigas on benthic community structures was dependent on habitat type, epifaunal communities associated with low densities of O. edulis and C. gigas did not differ and changes in benthic assemblage structure owing to the abundance of C. gigas were therefore attributed to the presence of oyster shells. Macrofaunal α-diversity increased with C. gigas cover in muddy habitats, while epifaunal α-diversity decreased at greater oyster densities. Macrofaunal β-diversity was greatest at low densities of C. gigas ; however, it did not differ between samples without and increased densities of oysters. In contrast, epifaunal β-diversity decreased with increasing oyster cover. Different environmental contexts enabled more independent predictions of the effect of C. gigas on native communities. These were found to be low and more importantly not differing from O. edulis . This indicates that, at low densities, C. gigas may be functionally equivalent to the declining native oyster in terms of biodiversity facilitation and aid in re-establishing benthic communities on shores where O. edulis has become extinct.

Lymphopenia predicts poor prognosis in patients with esophageal squamous cell carcinoma.

PubMed

Feng, Ji-Feng; Liu, Jin-Shi; Huang, Ying

2014-12-01

Lymphopenia is a useful predictive factor in several cancers. The aim of this study was to determine the prognostic value of lymphopenia in patients with esophageal squamous cell carcinoma (ESCC).A retrospective analysis of 307 consecutive patients who had undergone esophagectomy for ESCC was conducted. In our study, a lymphocyte count (LC) of fewer than 1.0 Giga/L was defined as lymphopenia. Kaplan-Meier method was used to calculate the cancer-specific survival (CSS). Cox regression analyses were performed to evaluate the prognostic factors. Receiver operating characteristic (ROC) curve was also plotted to verify the accuracy of LC for CSS prediction.The mean LC was 1.55 ± 0.64 Giga/L (range 0.4-3.7 Giga/L). The incidence of lymphopenia (LC < 1.0 Giga/L) was 16.6% (51/307). Patients with lymphopenia (LC < 1.0 Giga/L) had a significantly shorter 5-year CSS (21.6% vs 43.8%, P = 0.004). On multivariate analysis, lymphopenia (LC < 1.0 Giga/L) was an independent prognostic factor in patients with ESCC (P = 0.013). Lymphopenia had a hazard ratio (HR) of 1.579 [95% confidence interval (CI): 1.100-2.265] for CSS. ROC curve demonstrated that lymphopenia (LC < 1.0 Giga/L) predicts survival with a sensitivity of 86.2% and a specificity of 27.2%. Lymphopenia (LC < 1.0 Giga/L) is still an independent predictive factor for long-term survival in patients with ESCC.

Biodiversity research in the “big data” era: GigaScience and Pensoft work together to publish the most data-rich species description

PubMed Central

2013-01-01

With the publication of the first eukaryotic species description, combining transcriptomic, DNA barcoding, and micro-CT imaging data, GigaScience and Pensoft demonstrate how classical taxonomic description of a new species can be enhanced by applying new generation molecular methods, and novel computing and imaging technologies. This 'holistic’ approach in taxonomic description of a new species of cave-dwelling centipede is published in the Biodiversity Data Journal (BDJ), with coordinated data release in the GigaScience GigaDB database. PMID:24229463

Biodiversity research in the "big data" era: GigaScience and Pensoft work together to publish the most data-rich species description.

PubMed

Edmunds, Scott C; Hunter, Chris I; Smith, Vincent; Stoev, Pavel; Penev, Lyubomir

2013-10-28

With the publication of the first eukaryotic species description, combining transcriptomic, DNA barcoding, and micro-CT imaging data, GigaScience and Pensoft demonstrate how classical taxonomic description of a new species can be enhanced by applying new generation molecular methods, and novel computing and imaging technologies. This 'holistic' approach in taxonomic description of a new species of cave-dwelling centipede is published in the Biodiversity Data Journal (BDJ), with coordinated data release in the GigaScience GigaDB database.

GigaDB: promoting data dissemination and reproducibility

PubMed Central

Sneddon, Tam P.; Si Zhe, Xiao; Edmunds, Scott C.; Li, Peter; Goodman, Laurie; Hunter, Christopher I.

2014-01-01

Often papers are published where the underlying data supporting the research are not made available because of the limitations of making such large data sets publicly and permanently accessible. Even if the raw data are deposited in public archives, the essential analysis intermediaries, scripts or software are frequently not made available, meaning the science is not reproducible. The GigaScience journal is attempting to address this issue with the associated data storage and dissemination portal, the GigaScience database (GigaDB). Here we present the current version of GigaDB and reveal plans for the next generation of improvements. However, most importantly, we are soliciting responses from you, the users, to ensure that future developments are focused on the data storage and dissemination issues that still need resolving. Database URL: http://www.gigadb.org PMID:24622612

Molecular and functional characterization of a fads2 orthologue in the Amazonian teleost, Arapaima gigas.

PubMed

Lopes-Marques, Mónica; Ozório, Rodrigo; Amaral, Ricardo; Tocher, Douglas R; Monroig, Óscar; Castro, L Filipe C

2017-01-01

The Brazilian teleost Arapaima gigas is an iconic species of the Amazon. In recent years a significant effort has been put into the farming of arapaima to mitigate overfishing threats. However, little is known regarding the nutritional requirements of A. gigas in particular those for essential fatty acids including the long-chain polyunsaturated fatty acids (LC-PUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The ability to biosynthesize LC-PUFA is dependent upon the gene repertoire of fatty acyl desaturases (Fads) and elongases (Elovl), as well as their fatty acid specificities. In the present study we characterized both molecularly and functionally an orthologue of the desaturase fatty acid desaturase 2 (fads2) from A. gigas. The isolated sequence displayed the typical desaturase features, a cytochrome b 5 -domain with the heme-binding motif, two transmembrane domains and three histidine-rich regions. Functional characterization of A. gigas fads2 showed that, similar to other teleosts, the A. gigas fads2 exhibited a predominant Δ6 activity complemented with some capacity for Δ8 desaturation. Given that A. gigas belongs to one of the oldest teleostei lineages, the Osteoglossomorpha, these findings offer a significant insight into the evolution LC-PUFA biosynthesis in teleosts. Copyright © 2016 Elsevier Inc. All rights reserved.

Neuroprotective and Cognitive Enhancement Potentials of Angelica gigas Nakai Root: A Review

PubMed Central

Sowndhararajan, Kandhasamy; Kim, Songmun

2017-01-01

Angelica gigas Nakai is an important medicinal plant with health promoting properties that is used to treat many disorders. In traditional herbal medicine, the root of this plant is used to promote blood flow, to treat anemia, and is used as sedative or tonic agent. The root contains various bioactive metabolites; in particular, decursin and decursinol (pyranocoumarin type components) have been reported to possess various pharmacological properties. Recently, several in vitro and in vivo studies have reported that the crude extracts and isolated components from the root of A. gigas exhibited neuroprotective and cognitive enhancement effects. Neuronal damage or death is the most important factor for many neurodegenerative diseases. In addition, recent studies have clearly demonstrated the possible mechanisms behind the neuroprotective action of extracts/compounds from the root of A. gigas. In the present review, we summarized the neuroprotective and cognitive enhancement effects of extracts and individual compounds from A. gigas root. PMID:28452965

Neuroprotective and Cognitive Enhancement Potentials of Angelica gigas Nakai Root: A Review.

PubMed

Sowndhararajan, Kandhasamy; Kim, Songmun

2017-04-28

Angelica gigas Nakai is an important medicinal plant with health promoting properties that is used to treat many disorders. In traditional herbal medicine, the root of this plant is used to promote blood flow, to treat anemia, and is used as sedative or tonic agent. The root contains various bioactive metabolites; in particular, decursin and decursinol (pyranocoumarin type components) have been reported to possess various pharmacological properties. Recently, several in vitro and in vivo studies have reported that the crude extracts and isolated components from the root of A. gigas exhibited neuroprotective and cognitive enhancement effects. Neuronal damage or death is the most important factor for many neurodegenerative diseases. In addition, recent studies have clearly demonstrated the possible mechanisms behind the neuroprotective action of extracts/compounds from the root of A. gigas . In the present review, we summarized the neuroprotective and cognitive enhancement effects of extracts and individual compounds from A. gigas root.

Cloning and characterization of phenylalanine ammonia-lyase and cinnamate 4-hydroxylase and pyranocoumarin biosynthesis in Angelica gigas.

PubMed

Park, Jee Hee; Park, Nam Il; Xu, Hui; Park, Sang Un

2010-08-27

Phenylalanine ammonia-lyase (PAL) and cinnamate 4-hydroxylase (C4H) are important enzymes in the phenylpropanoid pathway and also in the accumulation of decursin (1) and decursinol angelate (2), which are major secondary metabolites in Angelica gigas. Using PCR with degenerate primers targeted to conserved regions of available orthologous PAL and C4H sequences, cDNAs encoding PAL and C4H from A. gigas were isolated. Both genes were used to show the comparative developmental and inducible accumulation of mRNAs in different organs and in suspension cells of A. gigas. PAL and C4H were induced most strongly in response to 300 microM methyl jasmonate treatment at 6 and 12 h, respectively, and were highly expressed in the fine roots of A. gigas. Similarly, the production of 1 and 2 was most prolific in the fine roots of the plant.

Cephalopods as Vectors of Harmful Algal Bloom Toxins in Marine Food Webs

PubMed Central

Lopes, Vanessa M.; Lopes, Ana Rita; Costa, Pedro; Rosa, Rui

2013-01-01

Here we summarize the current knowledge on the transfer and accumulation of harmful algal bloom (HAB)-related toxins in cephalopods (octopods, cuttlefishes and squids). These mollusks have been reported to accumulate several HAB-toxins, namely domoic acid (DA, and its isomers), saxitoxin (and its derivatives) and palytoxin (and palytoxin-like compounds) and, therefore, act as HAB-toxin vectors in marine food webs. Coastal octopods and cuttlefishes store considerably high levels of DA (amnesic shellfish toxin) in several tissues, but mainly in the digestive gland (DG)—the primary site of digestive absorption and intracellular digestion. Studies on the sub-cellular partitioning of DA in the soluble and insoluble fractions showed that nearly all DA (92.6%) is found in the cytosol. This favors the trophic transfer of the toxins since cytosolic substances can be absorbed by predators with greater efficiency. The available information on the accumulation and tissue distribution of DA in squids (e.g., in stranded Humboldt squids, Dosidicus gigas) is scarcer than in other cephalopod groups. Regarding paralytic shellfish toxins (PSTs), these organisms accumulate them at the greatest extent in DG >> kidneys > stomach > branchial hearts > posterior salivary glands > gills. Palytoxins are among the most toxic molecules identified and stranded octopods revealed high contamination levels, with ovatoxin (a palytoxin analogue) reaching 971 μg kg−1 and palytoxin reaching 115 μg kg−1 (the regulatory limit for PlTXs is 30 μg kg−1 in shellfish). Although the impacts of HAB-toxins in cephalopod physiology are not as well understood as in fish species, similar effects are expected since they possess a complex nervous system and highly developed brain comparable to that of the vertebrates. Compared to bivalves, cephalopods represent a lower risk of shellfish poisoning in humans, since they are usually consumed eviscerated, with exception of traditional dishes from the Mediterranean area. PMID:24018900

Cephalopods as vectors of harmful algal bloom toxins in marine food webs.

PubMed

Lopes, Vanessa M; Lopes, Ana Rita; Costa, Pedro; Rosa, Rui

2013-09-06

Here we summarize the current knowledge on the transfer and accumulation of harmful algal bloom (HAB)-related toxins in cephalopods (octopods, cuttlefishes and squids). These mollusks have been reported to accumulate several HAB-toxins, namely domoic acid (DA, and its isomers), saxitoxin (and its derivatives) and palytoxin (and palytoxin-like compounds) and, therefore, act as HAB-toxin vectors in marine food webs. Coastal octopods and cuttlefishes store considerably high levels of DA (amnesic shellfish toxin) in several tissues, but mainly in the digestive gland (DG)--the primary site of digestive absorption and intracellular digestion. Studies on the sub-cellular partitioning of DA in the soluble and insoluble fractions showed that nearly all DA (92.6%) is found in the cytosol. This favors the trophic transfer of the toxins since cytosolic substances can be absorbed by predators with greater efficiency. The available information on the accumulation and tissue distribution of DA in squids (e.g., in stranded Humboldt squids, Dosidicus gigas) is scarcer than in other cephalopod groups. Regarding paralytic shellfish toxins (PSTs), these organisms accumulate them at the greatest extent in DG > kidneys > stomach > branchial hearts > posterior salivary glands > gills. Palytoxins are among the most toxic molecules identified and stranded octopods revealed high contamination levels, with ovatoxin (a palytoxin analogue) reaching 971 μg kg⁻¹ and palytoxin reaching 115 μg kg⁻¹ (the regulatory limit for PlTXs is 30 μg kg⁻¹ in shellfish). Although the impacts of HAB-toxins in cephalopod physiology are not as well understood as in fish species, similar effects are expected since they possess a complex nervous system and highly developed brain comparable to that of the vertebrates. Compared to bivalves, cephalopods represent a lower risk of shellfish poisoning in humans, since they are usually consumed eviscerated, with exception of traditional dishes from the Mediterranean area.

Population structure of the giant garter snake, Thamnophis gigas

USGS Publications Warehouse

Paquin, M.M.; Wylie, G.D.; Routman, E.J.

2006-01-01

The giant garter snake, Thamnophis gigas, is a threatened species endemic to California's Central Valley. We tested the hypothesis that current watershed boundaries have caused genetic differentiation among populations of T. gigas. We sampled 14 populations throughout the current geographic range of T. gigas and amplified 859 bp from the mitochondrial gene ND4 and one nuclear microsatellite locus. DNA sequence variation from the mitochondrial gene indicates there is some genetic structuring of the populations, with high F ST values and unique haplotypes occurring at high frequency in several populations. We found that clustering populations by watershed boundary results in significant between-region genetic variance for mtDNA. However, analysis of allele frequencies at the microsatellite locus NSU3 reveals very low F ST values and little between-region variation in allele frequencies. The discordance found between mitochondrial and microsatellite data may be explained by aspects of molecular evolution and/or T. gigas life history characteristics. Differences in effective population size between mitochondrial and nuclear DNA, or male-biased gene flow, result in a lower migration rate of mitochondrial haplotypes relative to nuclear alleles. However, we cannot exclude homoplasy as one explanation for homogeneity found for the single microsatellite locus. The mitochondrial nucleotide sequence data supports conservation practices that identify separate management units for T. gigas. ?? Springer 2006.

Comparative Transcriptome Analysis of the Pacific Oyster Crassostrea gigas Characterized by Shell Colors: Identification of Genetic Bases Potentially Involved in Pigmentation

PubMed Central

Feng, Dandan; Li, Qi; Yu, Hong; Zhao, Xuelin; Kong, Lingfeng

2015-01-01

Background Shell color polymorphisms of Mollusca have contributed to development of evolutionary biology and population genetics, while the genetic bases and molecular mechanisms underlying shell pigmentation are poorly understood. The Pacific oyster (Crassostrea gigas) is one of the most important farmed oysters worldwide. Through successive family selection, four shell color variants (white, golden, black and partially pigmented) of C. gigas have been developed. To elucidate the genetic mechanisms of shell coloration in C. gigas and facilitate the selection of elite oyster lines with desired coloration patterns, differentially expressed genes (DEGs) were identified among the four shell color variants by RNA-seq. Results Digital gene expression generated over fifteen million reads per sample, producing expression data for 28,027 genes. A total number of 2,645 DEGs were identified from pair-wise comparisons, of which 432, 91, 43 and 39 genes specially were up-regulated in white, black, golden and partially pigmented shell of C. gigas, respectively. Three genes of Abca1, Abca3 and Abcb1 which belong to the ATP-binding cassette (ABC) transporters super-families were significantly associated with white shell formation. A tyrosinase transcript (CGI_10008737) represented consistent up-regulated pattern with golden coloration. We proposed that white shell variant of C. gigas could employ “endocytosis” to down-regulate notch level and to prevent shell pigmentation. Conclusion This study discovered some potential shell coloration genes and related molecular mechanisms by the RNA-seq, which would provide foundational information to further study on shell coloration and assist in selective breeding in C. gigas. PMID:26693729

The density and spatial arrangement of the invasive oyster Crassostrea gigas determines its impact on settlement of native oyster larvae

PubMed Central

Wilkie, Emma M; Bishop, Melanie J; O'Connor, Wayne A

2013-01-01

Understanding how the density and spatial arrangement of invaders is critical to developing management strategies of pest species. The Pacific oyster, Crassostrea gigas, has been translocated around the world for aquaculture and in many instances has established wild populations. Relative to other species of bivalve, it displays rapid suspension feeding, which may cause mortality of pelagic invertebrate larvae. We compared the effect on settlement of Sydney rock oyster, Saccostrea glomerata, larvae of manipulating the spatial arrangement and density of native S. glomerata, and non-native C. gigas. We hypothesized that while manipulations of dead oysters would reveal the same positive relationship between attachment surface area and S. glomerata settlement between the two species, manipulations of live oysters would reveal differing density-dependent effects between the native and non-native oyster. In the field, whether oysters were live or dead, more larvae settled on C. gigas than S. glomerata when substrate was arranged in monospecific clumps. When, however, the two species were interspersed, there were no differences in larval settlement between them. By contrast, in aquaria simulating a higher effective oyster density, more larvae settled on live S. glomerata than C. gigas. When C. gigas was prevented from suspension feeding, settlement of larvae on C. gigas was enhanced. By contrast, settlement was similar between the two species when dead. While the presently low densities of the invasive oyster C. gigas may enhance S. glomerata larval settlement in east Australian estuaries, future increases in densities could produce negative impacts on native oyster settlement. Synthesis and applications: Our study has shown that both the spatial arrangement and density of invaders can influence their impact. Hence, management strategies aimed at preventing invasive populations reaching damaging sizes should not only consider the threshold density at which impacts exceed some acceptable limit, but also how patch formation modifies this. PMID:24455120

GigaPan Technology to Enhance In-Class and In-Field Learning in Community College Settings

NASA Astrophysics Data System (ADS)

Villalobos, J. I.; Bentley, C.

2014-12-01

Community college students account for over 40% of all undergraduates in the United States as well as the majority of minority and non-traditional students attending undergraduate courses. Implementing innovative, cost effective, and formative pedagogies to the diverse backgrounds of students that typically enroll at a community is often a challenge. Interactive pedagogies in geology pose a unique challenge considering that students gain the most long-term knowledge when topics covered in a course are exposed to them in outdoor settings where they are allowed to explore and make connections. The ability to expose students to real world examples is challenging to many community college faculty considering that that many; lack funds or means for transportation of students, do not have administrative support on such endeavors, teach evening or night classes, or have a high percentage of students who are physically limited or have obligations to work and family. A joint collaborative between El Paso Community College (EPCC) and Northern Virginia Community College (NOVA) has explored the usage of GigaPan technology to create multi-layered online material to minimize these issues faced by many community college faculty and students. The primary layer of the online material is GigaPans of local geological sites that highlight large-scale structures in the El Paso, Texas region that are commonly used in local field trips and lab book material. The second layer is of Macro-GigaPans of hand samples of key outcrops from the primarily GigaPans which facilitate student learning, exploration, and ability to make connections by exploring smaller scale features of the primary layer. A third layer of online material, GigaPans of thin sections of hand samples (from secondary layers), and curriculum based on the GigaPans was then created to assist students in evaluating proposed hypotheses on the primary layers' geological origin. GigaPan cirriculum was utilized in introductory geology courses as well as a capstone Geological Field Methods course at El Paso Community College.

Mitochondrial genome of the endangered marine gastropod Strombus gigas Linnaeus, 1758 (Mollusca: Gastropoda).

PubMed

Márquez, Edna J; Castro, Erick R; Alzate, Juan F

2016-01-01

The queen conch Strombus gigas is an endangered marine gastropod of significant economic importance across the Greater Caribbean region. This work reports for the first time the complete mitochondrial genome of S. gigas, obtained by FLX 454 pyrosequencing. The mtDNA genome 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 gastropods.

Anti-tumor activities of decursinol angelate and decursin from Angelica gigas.

PubMed

Lee, Sanghyun; Lee, Yeon Sil; Jung, Sang Hoon; Shin, Kuk Hyun; Kim, Bak-Kwang; Kang, Sam Sik

2003-09-01

The in vivo anti-tumor activities of decursinol angelate (1) and decursin (2) isolated from the roots of Angelica gigas were investigated. These two compounds, when administered consecutively for 9 days at 50 and 100 mg/kg i.p. in mice, caused a significant increase in the life span and a significant decrease in the tumor weight and volume of mice inoculated with Sarcoma-180 tumor cells. These results suggest that decursinol angelate (1) and decursin (2) from A. gigas have anti-tumor activities.

Initial Data of Digital Correlation ECE with a Giga Hertz Sampling Digitizer

NASA Astrophysics Data System (ADS)

Tsuchiya, Hayato; Inagaki, Shigeru; Tokuzawa, Tokihiko; Nagayama, Yoshio

2015-03-01

The proposed Digital Correlation ECE (DCECE) technique is applied in Large Helical Device. DCECE is realized by the use of the Giga Hertz Sampling Digitizer. The waveform of intermediate frequency band of ECE, whose frequency is several giga hertz, can be discretized and saved directly. The discretized IF data can be used for the analysis of correlation ECE with arbitrary parameter of spatial resolution and temporal resolution. In this paper, the characteristic of DCECE and initial Data in LHD is introduced.

GIGA: a simple, efficient algorithm for gene tree inference in the genomic age

PubMed Central

2010-01-01

Background Phylogenetic relationships between genes are not only of theoretical interest: they enable us to learn about human genes through the experimental work on their relatives in numerous model organisms from bacteria to fruit flies and mice. Yet the most commonly used computational algorithms for reconstructing gene trees can be inaccurate for numerous reasons, both algorithmic and biological. Additional information beyond gene sequence data has been shown to improve the accuracy of reconstructions, though at great computational cost. Results We describe a simple, fast algorithm for inferring gene phylogenies, which makes use of information that was not available prior to the genomic age: namely, a reliable species tree spanning much of the tree of life, and knowledge of the complete complement of genes in a species' genome. The algorithm, called GIGA, constructs trees agglomeratively from a distance matrix representation of sequences, using simple rules to incorporate this genomic age information. GIGA makes use of a novel conceptualization of gene trees as being composed of orthologous subtrees (containing only speciation events), which are joined by other evolutionary events such as gene duplication or horizontal gene transfer. An important innovation in GIGA is that, at every step in the agglomeration process, the tree is interpreted/reinterpreted in terms of the evolutionary events that created it. Remarkably, GIGA performs well even when using a very simple distance metric (pairwise sequence differences) and no distance averaging over clades during the tree construction process. Conclusions GIGA is efficient, allowing phylogenetic reconstruction of very large gene families and determination of orthologs on a large scale. It is exceptionally robust to adding more gene sequences, opening up the possibility of creating stable identifiers for referring to not only extant genes, but also their common ancestors. We compared trees produced by GIGA to those in the TreeFam database, and they were very similar in general, with most differences likely due to poor alignment quality. However, some remaining differences are algorithmic, and can be explained by the fact that GIGA tends to put a larger emphasis on minimizing gene duplication and deletion events. PMID:20534164

GIGA: a simple, efficient algorithm for gene tree inference in the genomic age.

PubMed

Thomas, Paul D

2010-06-09

Phylogenetic relationships between genes are not only of theoretical interest: they enable us to learn about human genes through the experimental work on their relatives in numerous model organisms from bacteria to fruit flies and mice. Yet the most commonly used computational algorithms for reconstructing gene trees can be inaccurate for numerous reasons, both algorithmic and biological. Additional information beyond gene sequence data has been shown to improve the accuracy of reconstructions, though at great computational cost. We describe a simple, fast algorithm for inferring gene phylogenies, which makes use of information that was not available prior to the genomic age: namely, a reliable species tree spanning much of the tree of life, and knowledge of the complete complement of genes in a species' genome. The algorithm, called GIGA, constructs trees agglomeratively from a distance matrix representation of sequences, using simple rules to incorporate this genomic age information. GIGA makes use of a novel conceptualization of gene trees as being composed of orthologous subtrees (containing only speciation events), which are joined by other evolutionary events such as gene duplication or horizontal gene transfer. An important innovation in GIGA is that, at every step in the agglomeration process, the tree is interpreted/reinterpreted in terms of the evolutionary events that created it. Remarkably, GIGA performs well even when using a very simple distance metric (pairwise sequence differences) and no distance averaging over clades during the tree construction process. GIGA is efficient, allowing phylogenetic reconstruction of very large gene families and determination of orthologs on a large scale. It is exceptionally robust to adding more gene sequences, opening up the possibility of creating stable identifiers for referring to not only extant genes, but also their common ancestors. We compared trees produced by GIGA to those in the TreeFam database, and they were very similar in general, with most differences likely due to poor alignment quality. However, some remaining differences are algorithmic, and can be explained by the fact that GIGA tends to put a larger emphasis on minimizing gene duplication and deletion events.

Stochasticity of convection in Giga-LES data

NASA Astrophysics Data System (ADS)

De La Chevrotière, Michèle; Khouider, Boualem; Majda, Andrew J.

2016-09-01

The poor representation of tropical convection in general circulation models (GCMs) is believed to be responsible for much of the uncertainty in the predictions of weather and climate in the tropics. The stochastic multicloud model (SMCM) was recently developed by Khouider et al. (Commun Math Sci 8(1):187-216, 2010) to represent the missing variability in GCMs due to unresolved features of organized tropical convection. The SMCM is based on three cloud types (congestus, deep and stratiform), and transitions between these cloud types are formalized in terms of probability rules that are functions of the large-scale environment convective state and a set of seven arbitrary cloud timescale parameters. Here, a statistical inference method based on the Bayesian paradigm is applied to estimate these key cloud timescales from the Giga-LES dataset, a 24-h large-eddy simulation (LES) of deep tropical convection (Khairoutdinov et al. in J Adv Model Earth Syst 1(12), 2009) over a domain comparable to a GCM gridbox. A sequential learning strategy is used where the Giga-LES domain is partitioned into a few subdomains, and atmospheric time series obtained on each subdomain are used to train the Bayesian procedure incrementally. Convergence of the marginal posterior densities for all seven parameters is demonstrated for two different grid partitions, and sensitivity tests to other model parameters are also presented. A single column model simulation using the SMCM parameterization with the Giga-LES inferred parameters reproduces many important statistical features of the Giga-LES run, without any further tuning. In particular it exhibits intermittent dynamical behavior in both the stochastic cloud fractions and the large scale dynamics, with periods of dry phases followed by a coherent sequence of congestus, deep, and stratiform convection, varying on timescales of a few hours consistent with the Giga-LES time series. The chaotic variations of the cloud area fractions were captured fairly well both qualitatively and quantitatively demonstrating the stochastic nature of convection in the Giga-LES simulation.

Overexpression of cinnamate 4-hydroxylase gene enhances biosynthesis of decursinol angelate in Angelica gigas hairy roots.

PubMed

Park, Nam Il; Park, Jee Hee; Park, Sang Un

2012-02-01

Angelica gigas is a medicinal plant that produces pyranocoumarins, including decursin (D) and decursinol angelate (DA), which have neuroprotective, anticancer, and antiandrogenic effects. In this study, the coumarin biosynthetic pathway was engineered to increase the production of DA. Specifically, a vector was constructed which contained the A. gigas phenylalanine ammonia-lyase (AgPAL) and cinnamate 4-hydroxylase (AgC4H) genes that were driven by the cauliflower mosaic virus (CaMV) 35S promoter. Transgenic hairy roots that overexpressed AgPAL or AgC4H genes were obtained by using an Agrobacterium rhizogenes-mediated transformation system. Among them, only AgC4H-transgenic hairy root lines produced more DA than control transgenic hairy root lines. The enhanced gene expression corresponded to elevated C4H activities. This study showed the importance of C4H in the production of DA in A. gigas hairy root culture.

Combined metabolome and proteome analysis of the mantle tissue from Pacific oyster Crassostrea gigas exposed to elevated pCO2.

PubMed

Wei, Lei; Wang, Qing; Ning, Xuanxuan; Mu, Changkao; Wang, Chunlin; Cao, Ruiwen; Wu, Huifeng; Cong, Ming; Li, Fei; Ji, Chenglong; Zhao, Jianmin

2015-03-01

Ocean acidification (OA) has been found to affect an array of normal physiological processes in mollusks, especially posing a significant threat to the fabrication process of mollusk shell. In the current study, the impact of exposure to elevated pCO2 condition was investigated in mantle tissue of Crassostrea gigas by an integrated metabolomic and proteomic approach. Analysis of metabolome and proteome revealed that elevated pCO2 could affect energy metabolism in oyster C. gigas, marked by differentially altered ATP, succinate, MDH, PEPCK and ALDH levels. Moreover, the up-regulated calponin-2, tropomyosins and myosin light chains indicated that elevated pCO2 probably caused disturbances in cytoskeleton structure in mantle tissue of oyster C. gigas. This work demonstrated that a combination of proteomics and metabolomics could provide important insights into the effects of OA at molecular levels. Copyright © 2014 Elsevier Inc. All rights reserved.

Preparation and antioxidant activities of oligosaccharides from Crassostrea gigas.

PubMed

Wu, Shengjun; Huang, Xiaolian

2017-02-01

Oligosaccharides were prepared from Crassostrea gigas by hydrolysis of polysaccharide in C. gigas with peroxide oxygen (H2O2). The hydrolysates were cleared of protein, filtered, ultrafiltered and precipitated with absolute ethanol to give C. gigas oligosaccharides (CGOs). Factors affecting CGO yields, i.e., reaction time, temperature, and H2O2 concentration, were optimised as follows: 2.96h reaction time, 84.71°C reaction temperature, and 2.46% H2O2 concentration. Under these conditions, the maximum yield of CGOs reached 10.61%. The CGOs were then partially characterised by Fourier transform infrared spectroscopy, UV spectroscopy, monosaccharide composition, and antioxidant activities. Results indicate that CGOs possessed strong hydroxyl radical activity, 2,2-diphenyl-β-picrylhydrazyl-radical-scavenging activity and reducing capacity at a concentration of 100μg/mL. Copyright © 2016 Elsevier Ltd. All rights reserved.

Advancing Genomics through the Global Invertebrate Genomics Alliance (GIGA)

PubMed Central

Voolstra, Christian R.; Wörheide, Gert; Lopez, Jose V.

2017-01-01

The Global Invertebrate Genomics Alliance (GIGA), a collaborative network of diverse scientists, marked its second anniversary with a workshop in Munich, Germany, where international attendees focused on discussing current progress, milestones and bioinformatics resources. The community determined the recruitment and training talented researchers as one of the most pressing future needs and identified opportunities for network funding. GIGA also promotes future research efforts to prioritize taxonomic diversity and create new synergies. Here, we announce the generation of a central and simple data repository portal with a wide coverage of available sequence data, via the compagen platform, in parallel with more focused and specialized organism databases to globally advance invertebrate genomics. Therefore this article serves the objectives of GIGA by disseminating current progress and future prospects in the science of invertebrate genomics with the aim of promotion and facilitation of interdisciplinary and international research. PMID:28603454

Advancing Genomics through the Global Invertebrate Genomics Alliance (GIGA).

PubMed

Voolstra, Christian R; Wörheide, Gert; Lopez, Jose V

2017-03-01

The Global Invertebrate Genomics Alliance (GIGA), a collaborative network of diverse scientists, marked its second anniversary with a workshop in Munich, Germany, where international attendees focused on discussing current progress, milestones and bioinformatics resources. The community determined the recruitment and training talented researchers as one of the most pressing future needs and identified opportunities for network funding. GIGA also promotes future research efforts to prioritize taxonomic diversity and create new synergies. Here, we announce the generation of a central and simple data repository portal with a wide coverage of available sequence data, via the compagen platform, in parallel with more focused and specialized organism databases to globally advance invertebrate genomics. Therefore this article serves the objectives of GIGA by disseminating current progress and future prospects in the science of invertebrate genomics with the aim of promotion and facilitation of interdisciplinary and international research.

RAPID-COMMUNICATION Genetic diversity and differentiation in natural populations of Arapaima gigas from lower Amazon revealed by microsatellites.

PubMed

Fazzi-Gomes, P F; Melo, N; Palheta, G; Guerreiro, S; Amador, M; Ribeiro-Dos-Santos, A K; Santos, S; Hamoy, I

2017-02-08

Genetic variability is one of the important criteria for species conservation decisions. This study aimed to analyze the genetic diversity and the population differentiation of two natural populations of Arapaima gigas, a species with a long history of being commercially exploited. We collected 87 samples of A. gigas from Grande Curuai Lake and Paru Lake, located in the Lower Amazon region of Amazônia, Brazil, and genotyped these samples using a multiplex panel of microsatellite markers. Our results showed that the populations of A. gigas analyzed had high levels of genetic variability, which were similar to those described in previous studies. These two populations had a significant population differentiation supported by the estimates of F ST and R ST (0.06), by Bayesian analysis (K = 2), and by population assignment tests, which revealed a moderate genetic distance.

Large-scale parallel genome assembler over cloud computing environment.

PubMed

Das, Arghya Kusum; Koppa, Praveen Kumar; Goswami, Sayan; Platania, Richard; Park, Seung-Jong

2017-06-01

The size of high throughput DNA sequencing data has already reached the terabyte scale. To manage this huge volume of data, many downstream sequencing applications started using locality-based computing over different cloud infrastructures to take advantage of elastic (pay as you go) resources at a lower cost. However, the locality-based programming model (e.g. MapReduce) is relatively new. Consequently, developing scalable data-intensive bioinformatics applications using this model and understanding the hardware environment that these applications require for good performance, both require further research. In this paper, we present a de Bruijn graph oriented Parallel Giraph-based Genome Assembler (GiGA), as well as the hardware platform required for its optimal performance. GiGA uses the power of Hadoop (MapReduce) and Giraph (large-scale graph analysis) to achieve high scalability over hundreds of compute nodes by collocating the computation and data. GiGA achieves significantly higher scalability with competitive assembly quality compared to contemporary parallel assemblers (e.g. ABySS and Contrail) over traditional HPC cluster. Moreover, we show that the performance of GiGA is significantly improved by using an SSD-based private cloud infrastructure over traditional HPC cluster. We observe that the performance of GiGA on 256 cores of this SSD-based cloud infrastructure closely matches that of 512 cores of traditional HPC cluster.

The Global Invertebrate Genomics Alliance (GIGA): Developing Community Resources to Study Diverse Invertebrate Genomes

PubMed Central

2014-01-01

Over 95% of all metazoan (animal) species comprise the “invertebrates,” but very few genomes from these organisms have been sequenced. We have, therefore, formed a “Global Invertebrate Genomics Alliance” (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major challenges (e.g., species selection, sample collection and storage, sequence assembly, annotation, analytical tools) associated with genome/transcriptome sequencing across a large taxonomic spectrum. We aim to promote standards that will facilitate comparative approaches to invertebrate genomics and collaborations across the international scientific community. Candidate study taxa include species from Porifera, Ctenophora, Cnidaria, Placozoa, Mollusca, Arthropoda, Echinodermata, Annelida, Bryozoa, and Platyhelminthes, among others. GIGA will target 7000 noninsect/nonnematode species, with an emphasis on marine taxa because of the unrivaled phyletic diversity in the oceans. Priorities for selecting invertebrates for sequencing will include, but are not restricted to, their phylogenetic placement; relevance to organismal, ecological, and conservation research; and their importance to fisheries and human health. We highlight benefits of sequencing both whole genomes (DNA) and transcriptomes and also suggest policies for genomic-level data access and sharing based on transparency and inclusiveness. The GIGA Web site (http://giga.nova.edu) has been launched to facilitate this collaborative venture. PMID:24336862

Shell shape variation of queen conch Strombus gigas (Mesograstropoda: Strombidae) from Southwest Caribbean.

PubMed

Márquez, Edna Judith; Restrepo-Escobar, Natalia; Montoya-Herrera, Francisco Luis

2016-12-01

The endangered species Strombus gigas is a marine gastropod of significant economic importance through the Greater Caribbean region. In contrast to phenotypic plasticity, the role of genetics on shell variations in S. gigas has not been addressed so far, despite its importance in evolution, management and conservation of this species. This work used geometric morphometrics to investigate the phenotypic variation of 219 shells of S. gigas from eight sites of the Colombian Southwest Caribbean. Differences in mean size between sexes and among sites were contrasted by analysis of variance. Allometry was tested by multivariate regression and the hypothesis of common slope was contrasted by covariance multivariate analysis. Differences in the shell shape among sites were analyzed by principal component analysis. Sexual size dimorphism was not significant, whereas sexual shape dimorphism was significant and variable across sites. Differences in the shell shape among sites were concordant with genetic differences based on microsatellite data, supporting its genetic background. Besides, differences in the shell shape between populations genetically similar suggest a role of phenotypic plasticity in the morphometric variation of the shell shape. These outcomes evidence the role of genetic background and phenotypic plasticity in the shell shape of S. gigas. Thus, geometric morphometrics of shell shape may constitute a complementary tool to explore the genetic diversity of this species.

Effects of gamma irradiation on the yields of volatile extracts of Angelica gigas Nakai

NASA Astrophysics Data System (ADS)

Seo, Hye-Young; Kim, Jun-Hyoung; Song, Hyun-Pa; Kim, Dong-Ho; Byun, Myung-Woo; Kwon, Joog-Ho; Kim, Kyong-Su

2007-11-01

The study was carried out to determine the effects of gamma irradiation on the volatile flavor components including essential oils, of Angelica gigas Nakai. The volatile organic compounds from non- and irradiated A. gigas Nakai at doses of 1, 3, 5, 10 and 20 kGy were extracted by a simultaneous steam distillation and extraction (SDE) method and identified by GC/MS analysis. A total of 116 compounds were identified and quantified from non- and irradiated A. gigas Nakai. The major volatile compounds were identified 2,4,6-trimethyl heptane, α-pinene, camphene, α-limonene, β-eudesmol, α-murrolene and sphatulenol. Among these compounds, the amount of essential oils in non-irradiated sample were 77.13%, and the irradiated samples at doses of 1, 3, 5, 10 and 20 kGy were 84.98%, 83.70%, 83.94%, 82.84% and 82.58%, respectively. Oxygenated terpenes such as β-eudesmol, α-eudesmol, and verbenone were increased after irradiation but did not correlate with the irradiation dose. The yields of active substances such as essential oil were increased after irradiation; however, the yields of essential oils and the irradiation dose were not correlated. Thus, the profile of composition volatiles of A. gigas Nakai did not change with irradiation.

A novel family of cyclic oligopeptides derived from ribosomal peptide synthesis of an in planta-induced gene, gigA, in Epichloë endophytes of grasses.

PubMed

Johnson, Richard D; Lane, Geoffrey A; Koulman, Albert; Cao, Mingshu; Fraser, Karl; Fleetwood, Damien J; Voisey, Christine R; Dyer, Jolon M; Pratt, Jennifer; Christensen, Michael; Simpson, Wayne R; Bryan, Gregory T; Johnson, Linda J

2015-12-01

Fungal endophytes belonging to the genus Epichloë form associations with temperate grasses belonging to the sub-family Poöideae that range from mutualistic through to pathogenic. We previously identified a novel endophyte gene (designated gigA for grass induced gene) that is one of the most abundantly expressed fungal transcripts in endophyte-infected grasses and which is distributed and highly expressed in a wide range of Epichloë grass associations. Molecular and biochemical analyses indicate that gigA encodes a small secreted protein containing an imperfect 27 amino acid repeat that includes a kexin protease cleavage site. Kexin processing of GigA liberates within the plant multiple related products, named here as epichloëcyclins, which we have demonstrated by MS/MS to be cyclic peptidic in nature. Gene deletion of gigA leads to the elimination of all epichloëcyclins with no conspicuous phenotypic impact on the host grass, suggesting a possible bioactive role. This is a further example of a ribosomal peptide synthetic (RiPS) pathway operating within the Ascomycetes, and is the first description of such a pathway from a mutualistic symbiotic fungus from this Phylum. Copyright © 2015 Elsevier Inc. All rights reserved.

The Global Invertebrate Genomics Alliance (GIGA): developing community resources to study diverse invertebrate genomes.

PubMed

Bracken-Grissom, Heather; Collins, Allen G; Collins, Timothy; Crandall, Keith; Distel, Daniel; Dunn, Casey; Giribet, Gonzalo; Haddock, Steven; Knowlton, Nancy; Martindale, Mark; Medina, Mónica; Messing, Charles; O'Brien, Stephen J; Paulay, Gustav; Putnam, Nicolas; Ravasi, Timothy; Rouse, Greg W; Ryan, Joseph F; Schulze, Anja; Wörheide, Gert; Adamska, Maja; Bailly, Xavier; Breinholt, Jesse; Browne, William E; Diaz, M Christina; Evans, Nathaniel; Flot, Jean-François; Fogarty, Nicole; Johnston, Matthew; Kamel, Bishoy; Kawahara, Akito Y; Laberge, Tammy; Lavrov, Dennis; Michonneau, François; Moroz, Leonid L; Oakley, Todd; Osborne, Karen; Pomponi, Shirley A; Rhodes, Adelaide; Santos, Scott R; Satoh, Nori; Thacker, Robert W; Van de Peer, Yves; Voolstra, Christian R; Welch, David Mark; Winston, Judith; Zhou, Xin

2014-01-01

Over 95% of all metazoan (animal) species comprise the "invertebrates," but very few genomes from these organisms have been sequenced. We have, therefore, formed a "Global Invertebrate Genomics Alliance" (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major challenges (e.g., species selection, sample collection and storage, sequence assembly, annotation, analytical tools) associated with genome/transcriptome sequencing across a large taxonomic spectrum. We aim to promote standards that will facilitate comparative approaches to invertebrate genomics and collaborations across the international scientific community. Candidate study taxa include species from Porifera, Ctenophora, Cnidaria, Placozoa, Mollusca, Arthropoda, Echinodermata, Annelida, Bryozoa, and Platyhelminthes, among others. GIGA will target 7000 noninsect/nonnematode species, with an emphasis on marine taxa because of the unrivaled phyletic diversity in the oceans. Priorities for selecting invertebrates for sequencing will include, but are not restricted to, their phylogenetic placement; relevance to organismal, ecological, and conservation research; and their importance to fisheries and human health. We highlight benefits of sequencing both whole genomes (DNA) and transcriptomes and also suggest policies for genomic-level data access and sharing based on transparency and inclusiveness. The GIGA Web site (http://giga.nova.edu) has been launched to facilitate this collaborative venture.

Innovative uses of GigaPan Technology for Onsite and Distance Education

NASA Astrophysics Data System (ADS)

Bentley, C.; Schott, R. C.; Piatek, J. L.; Richards, B.

2013-12-01

GigaPans are gigapixel panoramic images that can be viewed at a wide range of magnifications, allowing users to explore them in various degrees of detail from the smallest scale to the full image extent. In addition to panoramic images captured with the GigaPan camera mount ('Dry Falls' - http://www.gigapan.com/gigapans/89093), users can also upload annotated images (For example, 'Massanutten sandstone slab with trace fossils (annotated)', http://www.gigapan.com/gigapans/124295) and satellite images (For example, 'Geology vs. Topography - State of Connecticut', http://www.gigapan.com/gigapans/111265). Panoramas with similar topics have been gathered together on the site in galleries, both user-generated and site-curated (For example, http://www.gigapan.com/galleries?categories=geology&page=1). Further innovations in display technology have also led to the development of improved viewers (for example, the annotations in the image linked above can be explored via paired viewers at http://coursecontent.nic.edu/bdrichards/gigapixelimages/callanview) GigaPan panoramas can be created through use of the GigaPan robotic camera mount and a digital camera (different models of the camera mount are available and work with a wide range of cameras). The camera mount can be used to create high-resolution pans ranging in scale from hand sample to outcrop up to landscape via the stitching software included with the robotic mount. The software can also be used to generate GigaPan images from other sources, such as thin section or satellite images, so these images can also be viewed with the online viewer. GigaPan images are typically viewed via a web-based interface that allows the user to interact with the image from the limits of the image detail up to the full panorama. After uploading, information can be added to panoramas with both text captions and geo-referencing (geo-located panoramas can then be viewed in Google Earth). Users can record specific locations and zoom levels in these images via "snapshots": these snapshots can direct others to the same location in the image as well as generate conversations with attached text comments. Users can also group related GigaPans by creating "galleries" of thematically related images (similar to photo albums). Gigapixel images can also be formatted for processing and viewing in an increasing number of platforms/modes as software vendors and internet browsers begin to provide 'add-in' support. This opens up opportunities for innovative adaptations for geoscience education. (For example, http://coursecontent.nic.edu/bdrichards/gigapixelimages/dryfalls) Specific applications of these images for geoscience educations include classroom activities and independent exercises that encourage students to take an active inquiry-based approach to understanding geoscience concepts at multiple skill levels. GigaPans in field research serve as both records of field locations and additional datasets for detailed analyses, such as observing color changes or variations in grain size. Related GigaPans can be also be presented together when embedded in webpages, useful for generating exercises for education purposes or for analyses of outcrops from the macro (landscape, outcrop) down to the micro scale (hand sample, thin section).

Material properties of zooplankton and nekton from the California current

NASA Astrophysics Data System (ADS)

Becker, Kaylyn

This study measured the material properties of zooplankton, Pacific hake (Merluccius productus), Humboldt squid (Dosidicus gigas), and two species of myctophids (Symbolophorus californiensis and Diaphus theta) collected from the California Current ecosystem. The density contrast (g) was measured for euphausiids, decapods (Sergestes similis), amphipods (Primno macropa, Phronima sp., and Hyperiid spp.), siphonophore bracts, chaetognaths, larval fish, crab megalopae, larval squid, and medusae. Morphometric data (length, width, and height) were collected for these taxa. Density contrasts varied within and between zooplankton taxa. The mean and standard deviation for euphausiid density contrast were 1.059 +/- 0.009. Relationships between zooplankton density contrast and morphometric measurements, geographic location, and environmental conditions were investigated. Site had a significant effect on euphausiid density contrast. Density contrasts of euphausiids collected in the same geographic area approximately 4-10 days apart were significantly higher (p < 0.001). Sound speed contrast (h) was measured for euphausiids and pelagic decapods (S. similis) and it varied between taxa. The mean and standard deviation for euphausiid sound speed were 1.019 +/- 0.009. Euphausiid mass was calculated from density measurements and volume, and a relationship between euphausiid mass and length was produced. We determined that euphausiid from volumes could be accurately estimated two dimensional measurements of animal body shape, and that biomass (or biovolume) could be accurately calculated from digital photographs of animals. Density contrast (g) was measured for zooplankton, pieces of hake flesh, myctophid flesh, and of the following Humboldt squid body parts: mantle, arms, tentacle, braincase, eyes, pen, and beak. The density contrasts varied within and between fish taxa, as well as among squid body parts. Effects of animal length and environmental conditions on nekton density contrast were investigated. The sound speed contrast (h) was measured for Pacific hake flesh, myctophid flesh, Humboldt squid mantle, and Humboldt squid braincase. Sound speed varied within and between nekton taxa. The material properties reported in this study can be used to improve target strength estimates from acoustic scattering models which would increase the accuracy of biomass estimates from acoustic surveys for these zooplankton and nekton.

Dynamics and fishery of the Peruvian hake: Between nature and man

NASA Astrophysics Data System (ADS)

Guevara-Carrasco, Renato; Lleonart, Jordi

Mean length in the catch of Peruvian hake ( Merluccius gayi peruanus) declined drastically by 8 cm in a few months in 1992. The 1991-93 El Niño event marked the beginning of changes in bottom environmental conditions, that along with other changes in the ecosystem, were the cause of the disappearance of large sized old hake from the traditional fishing grounds and the invasion of these areas by high concentrations of small sized young hake, traditionally distributed in the southern areas. A misinterpretation of this change gave an optimistic perception of the state of the stock, leading to a large increase of the fishing fleet and therefore to an increase of the fishing pressure on this resource. Catch increased quickly to very high levels in 1996, the fishery indicators of relative abundance remained stable, while global abundance of hake was diminishing. The resource responded to these natural variations of environment and to the intense fishing pressure with changes in some aspects of its biology and ecology. The most remarkable was the decrease of the length and age at first maturity that led to spawning by 1 year old (19 cm) individuals in a species whose observed longevity was 14 years. In 2002 a total and indefinite fishery closure was established by the Peruvian government and a technical commission for the hake recovery was created, which carried out continuous monitoring of the stock. After a closure of 20 months the indicators showed signs of recovery and the fishery was reopened in 2004. However, after an encouraging beginning during 2004 and the first quarter of 2005, neither abundance nor age structure had improved by the end of 2005, and in fact were deteriorating by the start of 2006. The survival of the age 2 and 3 groups was very low and few 4+ years old individuals were observed. Several factors working at different time scales have been proposed to explain the status of hake. The impact of the fishery, variations in the abiotic environment, predation by the jumbo squid ( Dosidicus gigas) and cannibalism were considered as potential causal factors of this decline.

Sex Ratio and Sex Reversal in Two-year-old Class of Oyster, Crassostrea gigas (Bivalvia: Ostreidae)

PubMed Central

Park, Jung Jun; Kim, Hyejin; Kang, Seung Wan; An, Cheul Min; Lee, Sung-Ho; Gye, Myung Chan; Lee, Jung Sick

2012-01-01

The sex ratio (F:M) in the same population of oyster, Crassostrea gigas at the commencement of the study (2007) was 1:1.0, but changed to 1:2.8 by the end of the study (2008). The sex reversal rate in two-year-old oysters was 40.2%. Specifically, female to male sex reversal rate was 66.1%, which is higher than the male to female sex reversal rate of 21.1%. The sex reversal pattern of C. gigas appears to go from male⇒female⇒male, and as such is determined to be rhythmical hermaphroditism. PMID:25949114

DNA barcoding reveals that the common cupped oyster in Taiwan is the Portuguese oyster Crassostrea angulata (Ostreoida; Ostreidae), not C. gigas

NASA Astrophysics Data System (ADS)

Hsiao, Sheng-Tai; Chuang, Shin-Chang; Chen, Kao-Sung; Ho, Ping-Ho; Wu, Chi-Lun; Chen, Chaolun Allen

2016-09-01

The Pacific cupped oyster, Crassostrea gigas, is one of the major aquacultural shellfish species that has been introduced to Europe and America from its native source in the West Pacific. In Taiwan, the cultivated cupped oysters along the west coast have been identified as C. gigas for over centuries; however, several molecular phylogenetic studies have cast doubt upon the existence of this species in Taiwan and adjacent waters. Indeed, our analyses of mitochondrial cytochrome oxidase I (COI) sequences from 313 Crassostrea collected from 12 locations along Taiwanese and southern Chinese coastlines confirm that all samples were the Portuguese oyster, C. angulata, rather than C. gigas. Multiple lines of evidence, including haplotypic and nucleotide diversity of the COI gene, demographic history, and population genetics, suggest that Taiwanese C. angulata is unique, probably experienced a sudden population expansion after the Last Glacial Maxima around 20,000 years ago, and has a significantly limited genetic connectivity across the Taiwan Strait. Our study applies an extended sampling and DNA barcoding to confirm the absence of C. gigas in natural and cultivated populations in Taiwan and southern China, where we only found C. angulata. We highlight the importance of conserving the gene pool of the C. angulata population in Taiwan, particularly considering the current threats by large-scale environmental disturbances such as marine pollution, habitat destruction, and climate change.

Toxic effects of heavy metal Cu2+ on the pacific oyster Crassostrea gigas

NASA Astrophysics Data System (ADS)

Gao, Ceng; Zhang, Xinxin; Li, Xiumei; Tang, Xuexi

2017-05-01

The effects of different concentrations of heavy metal ions on the survival of the Pacific oyster Crassostrea gigas were studied by using experimental ecology method in 96 h. The results showed that the LC50 of copper ion was 21.748mg/L and the safe concentration was 2.1748mg/L mg/L. Under the condition of laboratory, under laboratory conditions, the research of Cu2+ Stress on the C. gigas gill and digestive gland and adductor muscle tissue SOD, GPx and the induction of CAT activity. The results showed that the activities of SOD, GPx and CAT in the C. gigas were significantly changed by copper ion + stress. The results showed that in the low concentration Cu2+ treatment could induce the three kinds of enzymes, in the high concentration Cu2+ treatment group, SOD and CAT and GPx on the inhibition of the effect. The sensitivity of the three antioxidant enzymes to copper ion showed a certain difference. The sensitivity of the three kinds of tissue enzymes to Cu2+ treatment was digestive gland> fascia> gill. The experimental results show that the single factor for copper in water pollutants, the C. gigas digestive gland tissue SOD, GPX and CAT activity has certain significance to it, but will it as index applied to the actual water need further study.

DNA barcoding reveals that the common cupped oyster in Taiwan is the Portuguese oyster Crassostrea angulata (Ostreoida; Ostreidae), not C. gigas

PubMed Central

Hsiao, Sheng-Tai; Chuang, Shin-Chang; Chen, Kao-Sung; Ho, Ping-Ho; Wu, Chi-Lun; Chen, Chaolun Allen

2016-01-01

The Pacific cupped oyster, Crassostrea gigas, is one of the major aquacultural shellfish species that has been introduced to Europe and America from its native source in the West Pacific. In Taiwan, the cultivated cupped oysters along the west coast have been identified as C. gigas for over centuries; however, several molecular phylogenetic studies have cast doubt upon the existence of this species in Taiwan and adjacent waters. Indeed, our analyses of mitochondrial cytochrome oxidase I (COI) sequences from 313 Crassostrea collected from 12 locations along Taiwanese and southern Chinese coastlines confirm that all samples were the Portuguese oyster, C. angulata, rather than C. gigas. Multiple lines of evidence, including haplotypic and nucleotide diversity of the COI gene, demographic history, and population genetics, suggest that Taiwanese C. angulata is unique, probably experienced a sudden population expansion after the Last Glacial Maxima around 20,000 years ago, and has a significantly limited genetic connectivity across the Taiwan Strait. Our study applies an extended sampling and DNA barcoding to confirm the absence of C. gigas in natural and cultivated populations in Taiwan and southern China, where we only found C. angulata. We highlight the importance of conserving the gene pool of the C. angulata population in Taiwan, particularly considering the current threats by large-scale environmental disturbances such as marine pollution, habitat destruction, and climate change. PMID:27666088

DNA barcoding reveals that the common cupped oyster in Taiwan is the Portuguese oyster Crassostrea angulata (Ostreoida; Ostreidae), not C. gigas.

PubMed

Hsiao, Sheng-Tai; Chuang, Shin-Chang; Chen, Kao-Sung; Ho, Ping-Ho; Wu, Chi-Lun; Chen, Chaolun Allen

2016-09-26

The Pacific cupped oyster, Crassostrea gigas, is one of the major aquacultural shellfish species that has been introduced to Europe and America from its native source in the West Pacific. In Taiwan, the cultivated cupped oysters along the west coast have been identified as C. gigas for over centuries; however, several molecular phylogenetic studies have cast doubt upon the existence of this species in Taiwan and adjacent waters. Indeed, our analyses of mitochondrial cytochrome oxidase I (COI) sequences from 313 Crassostrea collected from 12 locations along Taiwanese and southern Chinese coastlines confirm that all samples were the Portuguese oyster, C. angulata, rather than C. gigas. Multiple lines of evidence, including haplotypic and nucleotide diversity of the COI gene, demographic history, and population genetics, suggest that Taiwanese C. angulata is unique, probably experienced a sudden population expansion after the Last Glacial Maxima around 20,000 years ago, and has a significantly limited genetic connectivity across the Taiwan Strait. Our study applies an extended sampling and DNA barcoding to confirm the absence of C. gigas in natural and cultivated populations in Taiwan and southern China, where we only found C. angulata. We highlight the importance of conserving the gene pool of the C. angulata population in Taiwan, particularly considering the current threats by large-scale environmental disturbances such as marine pollution, habitat destruction, and climate change.

Machine Learning-Aided, Robust Wideband Spectrum Sensing for Cognitive Radios

DTIC Science & Technology

2015-06-12

to even Approved for public release; distribution is unlimited. 2 on the order of a giga -Hertz (GHz). Due to wide bandwidth and noncontiguous...Frequency Band CS Compressive Sampling DFT Discrete Fourier Transform EMI Electro Magnetic Interference FFT Fast Fourier Transform GHz Giga Hertz Hz Hertz

Effect of essential oil and supercritical carbon dioxide extract from the root of Angelica gigas on human EEG activity.

PubMed

Sowndhararajan, Kandhasamy; Seo, Min; Kim, Minju; Kim, Heeyeon; Kim, Songmun

2017-08-01

The present study aimed to investigate the effect of inhalation of essential oil (EO) and supercritical carbon dioxide extract (SC-CO 2 ) from the root of A. gigas on human electroencephalographic (EEG) activity. For this purpose, the EO was obtained from the root of A. gigas by steam distillation and SC-CO 2 was obtained at 50 °C and 400 bar for 1 h. The EEG readings were recorded using the QEEG-8 system from 8 electrode sites according to the International 10-20 system. In the EEG study, the absolute low beta (left temporal and left parietal) activity significantly increased during the inhalation of EO. In the case of SC-CO 2 inhalation, there was no significant change in absolute waves. The results revealed that the EO of A. gigas root produced significant changes in the absolute low beta activity and these changes may enhance the language learning abilities of human brain. Copyright © 2017. Published by Elsevier Ltd.

Climate warming and the carbon cycle in the permafrost zone of the former Soviet Union

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolchugina, T.P.; Vinson, T.S.

1993-01-01

The continuous permafrost zone of the former Soviet Union occupies 5% of the land surface area of the earth and stores a significant amount of carbon. Climate warming could disrupt the balance between carbon (C) accumulation and decomposition processes within the permafrost zone. Increased temperatures may accelerate the rate of organic matter decomposition. At the same time, the productivity of vegetation may increase in response to warming. To assess the future carbon cycle within the permafrost zone under a climate-warming scenario, it is necessary to quantify present carbon pools and fluxes. The present carbon cycle was assessed on the basismore » of an ecosystem/ecoregion approach. Under the present climate, the phytomass carbon pool was estimated at 17.0 Giga tons. The mortmass (coarse woody debris) carbon pool was estimated at 16.1 Giga tons. The soil carbon pool, including peatlands, was 139.4 Giga tons. The present rate of carbon turnover was 1.6 Giga tons/yr. (Copyright (c) 1993 by John Wiley and Sons, Ltd.)« less

SNP mining in Crassostrea gigas EST data: transferability to four other Crassostrea species, phylogenetic inferences and outlier SNPs under selection.

PubMed

Zhong, Xiaoxiao; Li, Qi; Yu, Hong; Kong, Lingfeng

2014-01-01

Oysters, with high levels of phenotypic plasticity and wide geographic distribution, are a challenging group for taxonomists and phylogenetics. Our study is intended to generate new EST-SNP markers and to evaluate their potential for cross-species utilization in phylogenetic study of the genus Crassostrea. In the study, 57 novel SNPs were developed from an EST database of C. gigas by the HRM (high-resolution melting) method. Transferability of 377 SNPs developed for C. gigas was examined on four other Crassostrea species: C. sikamea, C. angulata, C. hongkongensis and C. ariakensis. Among the 377 primer pairs tested, 311 (82.5%) primers showed amplification in C. sikamea, 353 (93.6%) in C. angulata, 254 (67.4%) in C. hongkongensis and 253 (67.1%) in C. ariakensis. A total of 214 SNPs were found to be transferable to all four species. Phylogenetic analyses showed that C. hongkongensis was a sister species of C. ariakensis and that this clade was sister to the clade containing C. sikamea, C. angulata and C. gigas. Within this clade, C. gigas and C. angulata had the closest relationship, with C. sikamea being the sister group. In addition, we detected eight SNPs as potentially being under selection by two outlier tests (fdist and hierarchical methods). The SNPs studied here should be useful for genetic diversity, comparative mapping and phylogenetic studies across species in Crassostrea and the candidate outlier SNPs are worth exploring in more detail regarding association genetics and functional studies.

Genomic analysis of the Pacific oyster (Crassostrea gigas) reveals possible conservation of vertebrate sex determination in a mollusc.

PubMed

Zhang, Na; Xu, Fei; Guo, Ximing

2014-09-11

Despite the prevalence of sex in animal kingdom, we have only limited understanding of how sex is determined and evolved in many taxa. The mollusc Pacific oyster Crassostrea gigas exhibits complex modes of sexual reproduction that consists of protandric dioecy, sex change, and occasional hermaphroditism. This complex system is controlled by both environmental and genetic factors through unknown molecular mechanisms. In this study, we investigated genes related to sex-determining pathways in C. gigas through transcriptome sequencing and analysis of female and male gonads. Our analysis identified or confirmed novel homologs in the oyster of key sex-determining genes (SoxH or Sry-like and FoxL2) that were thought to be vertebrate-specific. Their expression profile in C. gigas is consistent with conserved roles in sex determination, under a proposed model where a novel testis-determining CgSoxH may serve as a primary regulator, directly or indirectly interacting with a testis-promoting CgDsx and an ovary-promoting CgFoxL2. Our findings plus previous results suggest that key vertebrate sex-determining genes such as Sry and FoxL2 may not be inventions of vertebrates. The presence of such genes in a mollusc with expression profiles consistent with expected roles in sex determination suggest that sex determination may be deeply conserved in animals, despite rapid evolution of the regulatory pathways that in C. gigas may involve both genetic and environmental factors. Copyright © 2014 Zhang et al.

Genomic Analysis of the Pacific Oyster (Crassostrea gigas) Reveals Possible Conservation of Vertebrate Sex Determination in a Mollusc

PubMed Central

Zhang, Na; Xu, Fei; Guo, Ximing

2014-01-01

Despite the prevalence of sex in animal kingdom, we have only limited understanding of how sex is determined and evolved in many taxa. The mollusc Pacific oyster Crassostrea gigas exhibits complex modes of sexual reproduction that consists of protandric dioecy, sex change, and occasional hermaphroditism. This complex system is controlled by both environmental and genetic factors through unknown molecular mechanisms. In this study, we investigated genes related to sex-determining pathways in C. gigas through transcriptome sequencing and analysis of female and male gonads. Our analysis identified or confirmed novel homologs in the oyster of key sex-determining genes (SoxH or Sry-like and FoxL2) that were thought to be vertebrate-specific. Their expression profile in C. gigas is consistent with conserved roles in sex determination, under a proposed model where a novel testis-determining CgSoxH may serve as a primary regulator, directly or indirectly interacting with a testis-promoting CgDsx and an ovary-promoting CgFoxL2. Our findings plus previous results suggest that key vertebrate sex-determining genes such as Sry and FoxL2 may not be inventions of vertebrates. The presence of such genes in a mollusc with expression profiles consistent with expected roles in sex determination suggest that sex determination may be deeply conserved in animals, despite rapid evolution of the regulatory pathways that in C. gigas may involve both genetic and environmental factors. PMID:25213692

Protective Effect of Decursin Extracted from Angelica gigas in Male Infertility via Nrf2/HO-1 Signaling Pathway

PubMed Central

Bae, Woong Jin; Ha, U. Syn; Choi, Jin Bong; Kim, Kang Sup; Kim, Su Jin; Cho, Hyuk Jin; Hong, Sung Hoo; Lee, Ji Youl; Wang, Zhiping; Hwang, Sung Yeoun; Kim, Sae Woong

2016-01-01

Higher testicular temperature results in altered spermatogenesis due to heat-related oxidative stress. We examined the effects of decursin extracted from Angelica gigas Nakai on antioxidant activity in vitro and in a cryptorchidism-induced infertility rat model. TM3 Leydig cell viability was measured based on oxidative stress according to treatment. Either distilled water or AG 400 mg/kg of A. gigas extract was administered orally for 4 weeks after unilateral cryptorchidism was induced. After 1, 2, and 4 weeks, six rats from the control group and six rats from treatment group were sacrificed. Testicular weight, semen quality, antioxidant activities, nuclear factor erythroid 2-related factor 2 (Nrf2) protein, and mRNA expression of Nrf2-regulated genes were analyzed. Treatment with A. gigas extract (1) protected TM3 cells against oxidative stress in a dose-dependent manner, (2) improved the mean weight of the cryptorchid testis, (3) maintained sperm counts, motility, and spermatogenic cell density, (4) decreased levels of 8-hydroxy-2-deoxyguanosine (8-OHdG) and increased levels of superoxide dismutase (SOD), (5) significantly increased Nrf2 and heme oxygenase-1 (HO-1), and (6) significantly decreased apoptosis. This study suggests that decursin extracted from A. gigas is a supplemental agent that can reduce oxidative stress by Nrf2-mediated upregulation of HO-1 in rat experimentally induced unilateral cryptorchidism and may improve cryptorchidism-induced infertility. PMID:27034737

Protective Effect of Decursin Extracted from Angelica gigas in Male Infertility via Nrf2/HO-1 Signaling Pathway.

PubMed

Bae, Woong Jin; Ha, U Syn; Choi, Jin Bong; Kim, Kang Sup; Kim, Su Jin; Cho, Hyuk Jin; Hong, Sung Hoo; Lee, Ji Youl; Wang, Zhiping; Hwang, Sung Yeoun; Kim, Sae Woong

2016-01-01

Higher testicular temperature results in altered spermatogenesis due to heat-related oxidative stress. We examined the effects of decursin extracted from Angelica gigas Nakai on antioxidant activity in vitro and in a cryptorchidism-induced infertility rat model. TM3 Leydig cell viability was measured based on oxidative stress according to treatment. Either distilled water or AG 400 mg/kg of A. gigas extract was administered orally for 4 weeks after unilateral cryptorchidism was induced. After 1, 2, and 4 weeks, six rats from the control group and six rats from treatment group were sacrificed. Testicular weight, semen quality, antioxidant activities, nuclear factor erythroid 2-related factor 2 (Nrf2) protein, and mRNA expression of Nrf2-regulated genes were analyzed. Treatment with A. gigas extract (1) protected TM3 cells against oxidative stress in a dose-dependent manner, (2) improved the mean weight of the cryptorchid testis, (3) maintained sperm counts, motility, and spermatogenic cell density, (4) decreased levels of 8-hydroxy-2-deoxyguanosine (8-OHdG) and increased levels of superoxide dismutase (SOD), (5) significantly increased Nrf2 and heme oxygenase-1 (HO-1), and (6) significantly decreased apoptosis. This study suggests that decursin extracted from A. gigas is a supplemental agent that can reduce oxidative stress by Nrf2-mediated upregulation of HO-1 in rat experimentally induced unilateral cryptorchidism and may improve cryptorchidism-induced infertility.

Effect of linear alkylbenzene mixtures and sanitary sewage in biochemical and molecular responses in pacific oyster Crassostrea gigas.

PubMed

Flores-Nunes, Fabrício; Mattos, Jacó J; Zacchi, Flávia L; Serrano, Miguel A S; Piazza, Clei E; Sasaki, Silvio T; Taniguchi, Satie; Bicego, Márcia C; Melo, Cláudio M R; Bainy, Afonso C D

2015-11-01

Urban effluents are rich in nutrients, organic matter, pharmaceuticals and personal care products (PPCPs), pesticides, hydrocarbons, surfactants, and others. Previous studies have shown that oysters Crassostrea gigas accumulate significant levels of linear alkylbenzenes (LABs) in sanitary sewage contaminated sites, but there is little information about its toxicological effects in marine bivalves. The aim of this study was to analyze the transcription of genes in two tissues of C. gigas exposed for 12, 24, and 36 h to LABs or sanitary sewage. Likewise, the activity of antioxidant and biotransformation enzymes was measured in oysters exposed for 36 h in all groups. Oysters exposed to LABs and oysters exposed to sanitary sewage showed different patterns of transcriptional responses. LAB-exposed oysters showed lower level of biological responses than the oysters exposed to sanitary sewage. Despite the ability of the oyster C. gigas to accumulate LABs (28-fold), the data indicate that these contaminants are not the cause for the transcriptional responses observed in oysters exposed to sanitary sewage. Possibly, the biological changes observed in the sanitary sewage-exposed oysters are associated with the presence of other contaminants, which might have caused synergistic, additive, or antagonistic effects. The results show that FABP-like and GST-ω-like messenger RNAs (mRNAs) have a rapid response in tissues of oyster C. gigas exposed to sanitary sewage, suggesting a possible protective response and a role in maintaining homeostasis of these organisms.

Molecular adaptation in the world's deepest-living animal: Insights from transcriptome sequencing of the hadal amphipod Hirondellea gigas.

PubMed

Lan, Yi; Sun, Jin; Tian, Renmao; Bartlett, Douglas H; Li, Runsheng; Wong, Yue Him; Zhang, Weipeng; Qiu, Jian-Wen; Xu, Ting; He, Li-Sheng; Tabata, Harry G; Qian, Pei-Yuan

2017-07-01

The Challenger Deep in the Mariana Trench is the deepest point in the oceans of our planet. Understanding how animals adapt to this harsh environment characterized by high hydrostatic pressure, food limitation, dark and cold is of great scientific interest. Of the animals dwelling in the Challenger Deep, amphipods have been captured using baited traps. In this study, we sequenced the transcriptome of the amphipod Hirondellea gigas collected at a depth of 10,929 m from the East Pond of the Challenger Deep. Assembly of these sequences resulted in 133,041 contigs and 22,046 translated proteins. Functional annotation of these contigs was made using the go and kegg databases. Comparison of these translated proteins with those of four shallow-water amphipods revealed 10,731 gene families, of which 5659 were single-copy orthologs. Base substitution analysis on these single-copy orthologs showed that 62 genes are positively selected in H. gigas, including genes related to β-alanine biosynthesis, energy metabolism and genetic information processing. For multiple-copy orthologous genes, gene family expansion analysis revealed that cold-inducible proteins (i.e., transcription factors II A and transcription elongation factor 1) as well as zinc finger domains are expanded in H. gigas. Overall, our results indicate that genetic adaptation to the hadal environment by H. gigas may be mediated by both gene family expansion and amino acid substitutions of specific proteins. © 2017 John Wiley & Sons Ltd.

Connectivity and genetic structure of the queen conch on the Mesoamerican Reef

NASA Astrophysics Data System (ADS)

Machkour-M'Rabet, Salima; Cruz-Medina, Jorge; García-De León, Francisco J.; De Jesús-Navarrete, Alberto; Hénaut, Yann

2017-06-01

The queen conch ( Strombus gigas) is a commercially important marine invertebrate that is widely distributed throughout the western Atlantic, from Bermuda to Brazil. Intense exploitation has resulted in a decrease in population numbers of this species, which is listed as protected from commercial exploitation under IUCN and CITES. Previous studies on population genetics have demonstrated contrasting results in terms of the population structure of S. gigas. This research analyzed the genetic connectivity of the queen conch over a wide area of the Mesoamerican Reef System to determine whether S. gigas presents one panmictic population or a more complex structure. Furthermore, we evaluated the risk of local extinction by establishing the genetic diversity of the studied populations. High resolution was obtained for the five ISSR markers used for a total of 190 individuals, from seven localities along the Mesoamerican Reef. Our results reject the panmictic structure hypothesis for the queen conch in the study area and demonstrate genetic patchiness, indicating general homogeneity among localities that present an isolation-by-distance pattern. However, some genetic temporal variation was confirmed for the Cozumel locality. Furthermore, our results reveal self-recruitment for the Alacranes Reef aggregation and suggest sufficient connectivity with localities on the Caribbean coast to maintain high genetic diversity. With regard to genetic diversity, the results demonstrate that the queen conch is not genetically threatened in the study area. This is probably due to high annual recruitment within Caribbean queen conch aggregations, and suggests that S. gigas is a highly resilient organism. We advocate that the appropriate management of S. gigas (fishing quota and/or closed season) must be followed to attain a rapid recovery of queen conch populations. This study represents a fundamental step in the understanding of the dynamic population structure of S. gigas in the Mesoamerican Reef and is an important contribution toward improving the future management of this commercially protected species.

Effects of Non-Indigenous Oysters on Microbial Diversity and Ecosystem Functioning

PubMed Central

Green, Dannielle S.; Boots, Bas; Crowe, Tasman P.

2012-01-01

Invasive ecosystem engineers can physically and chemically alter the receiving environment, thereby affecting biodiversity and ecosystem functioning. The Pacific oyster, Crassostrea gigas, invasive throughout much of the world, can establish dense populations monopolising shorelines and possibly altering ecosystem processes including decomposition and nutrient cycling. The effects of increasing cover of invasive C. gigas on ecosystem processes and associated microbial assemblages in mud-flats were tested experimentally in the field. Pore-water nutrients (NH4 + and total oxidised nitrogen), sediment chlorophyll content, microbial activity, total carbon and nitrogen, and community respiration (CO2 and CH4) were measured to assess changes in ecosystem functioning. Assemblages of bacteria and functionally important microbes, including methanogens, methylotrophs and ammonia-oxidisers were assessed in the oxic and anoxic layers of sediment using terminal restriction length polymorphism of the bacterial 16S rRNA, mxaF, amoA and archaeal mcrA genes respectively. At higher covers (40 and 80%) of oysters there was significantly greater microbial activity, increased chlorophyll content, CO2 (13 fold greater) and CH4 (6 fold greater) emission from the sediment compared to mud-flats without C. gigas. At 10% cover, C. gigas increased the concentration of total oxidised nitrogen and altered the assemblage structure of ammonia-oxidisers and methanogens. Concentrations of pore-water NH4 + were increased by C. gigas regardless of cover. Invasive species can alter ecosystem functioning not only directly, but also indirectly, by affecting microbial communities vital for the maintenance of ecosystem processes, but the nature and magnitude of these effects can be non-linear, depending on invader abundance. PMID:23144762

Metabolic Cost of Protein Synthesis in Larvae of the Pacific Oyster (Crassostrea gigas) Is Fixed Across Genotype, Phenotype, and Environmental Temperature.

PubMed

Lee, Jimmy W; Applebaum, Scott L; Manahan, Donal T

2016-06-01

The energy made available through catabolism of specific biochemical reserves is constant using standard thermodynamic conversion equivalents (e.g., 24.0 J mg protein(-1)). In contrast, measurements reported for the energy cost of synthesis of specific biochemical constituents are highly variable. In this study, we measured the metabolic cost of protein synthesis and determined whether this cost was influenced by genotype, phenotype, or environment. We focused on larval stages of the Pacific oyster Crassostrea gigas, a species that offers several experimental advantages: availability of genetically pedigreed lines, manipulation of ploidy, and tractability of larval forms for in vivo studies of physiological processes. The cost of protein synthesis was measured in larvae of C. gigas for 1) multiple genotypes, 2) phenotypes with different growth rates, and 3) different environmental temperatures. For all treatments, the cost of protein synthesis was within a narrow range--near the theoretical minimum--with a fixed cost (mean ± one standard error, n = 21) of 2.1 ± 0.2 J (mg protein synthesized)(-1) We conclude that there is no genetic variation in the metabolic cost of protein synthesis, thereby simplifying bioenergetic models. Protein synthesis is a major component of larval metabolism in C. gigas, accounting for more than half the metabolic rate in diploid (59%) and triploid larvae (54%). These results provide measurements of metabolic cost of protein synthesis in larvae of C. gigas, an indicator species for impacts of ocean change, and provide a quantitative basis for evaluating the cost of resilience. © 2016 Marine Biological Laboratory.

Counting the dead to determine the source and transmission of the marine herpesvirus OsHV-1 in Crassostrea gigas.

PubMed

Whittington, Richard J; Paul-Pont, Ika; Evans, Olivia; Hick, Paul; Dhand, Navneet K

2018-04-10

Marine herpesviruses are responsible for epizootics in economically, ecologically and culturally significant taxa. The recent emergence of microvariants of Ostreid herpesvirus 1 (OsHV-1) in Pacific oysters Crassostrea gigas has resulted in socioeconomic losses in Europe, New Zealand and Australia however, there is no information on their origin or mode of transmission. These factors need to be understood because they influence the way the disease may be prevented and controlled. Mortality data obtained from experimental populations of C. gigas during natural epizootics of OsHV-1 disease in Australia were analysed qualitatively. In addition we compared actual mortality data with those from a Reed-Frost model of direct transmission and analysed incubation periods using Sartwell's method to test for the type of epizootic, point source or propagating. We concluded that outbreaks were initiated from an unknown environmental source which is unlikely to be farmed oysters in the same estuary. While direct oyster-to-oyster transmission may occur in larger oysters if they are in close proximity (< 40 cm), it did not explain the observed epizootics, point source exposure and indirect transmission being more common and important. A conceptual model is proposed for OsHV-1 index case source and transmission, leading to endemicity with recurrent seasonal outbreaks. The findings suggest that prevention and control of OsHV-1 in C. gigas will require multiple interventions. OsHV-1 in C. gigas, which is a sedentary animal once beyond the larval stage, is an informative model when considering marine host-herpesvirus relationships.

Transition in organ function during the evolution of air-breathing; insights from Arapaima gigas, an obligate air-breathing teleost from the Amazon.

PubMed

Brauner, C J; Matey, V; Wilson, J M; Bernier, N J; Val, A L

2004-04-01

The transition from aquatic to aerial respiration is associated with dramatic physiological changes in relation to gas exchange, ion regulation, acid-base balance and nitrogenous waste excretion. Arapaima gigas is one of the most obligate extant air-breathing fishes, representing a remarkable model system to investigate (1) how the transition from aquatic to aerial respiration affects gill design and (2) the relocation of physiological processes from the gills to the kidney during the evolution of air-breathing. Arapaima gigas undergoes a transition from water- to air-breathing during development, resulting in striking changes in gill morphology. In small fish (10 g), the gills are qualitatively similar in appearance to another closely related water-breathing fish (Osteoglossum bicirrhosum); however, as fish grow (100-1000 g), the inter-lamellar spaces become filled with cells, including mitochondria-rich (MR) cells, leaving only column-shaped filaments. At this stage, there is a high density of MR cells and strong immunolocalization of Na(+)/K(+)-ATPase along the outer cell layer of the gill filament. Despite the greatly reduced overall gill surface area, which is typical of obligate air-breathing fish, the gills may remain an important site for ionoregulation and acid-base regulation. The kidney is greatly enlarged in A. gigas relative to that in O. bicirrhosum and may comprise a significant pathway for nitrogenous waste excretion. Quantification of the physiological role of the gill and the kidney in A. gigas during development and in adults will yield important insights into developmental physiology and the evolution of air-breathing.

The role of the mussel Mytilus spp. in the transmission of ostreid herpesvirus-1 microVar.

PubMed

O' Reilly, A J; Laide, C; Maloy, A; Hutton, S; Bookelaar, B; O' Sullivan, K; Lynch, S A; Culloty, S C

2017-12-21

The Pacific oyster Crassostrea gigas contributes significantly to global aquaculture; however, C. gigas culture has been affected by ostreid herpesvirus-1 (OsHV-1) and variants. The dynamics of how the virus maintains itself at culture sites is unclear and the role of carriers, reservoirs or hosts is unknown. Both wild and cultured mussels Mytilus spp. (Mytilus edulis, Mytilus galloprovincialis and hybrids) are commonly found at C. gigas culture sites. The objective of this study was to investigate if Mytilus spp. can harbour the virus and if viral transmission can occur between mussels and oysters. Mytilus spp. living at oyster trestles, 400-500 m higher up the shore from the trestles and up to 26 km at non-culture sites were screened for OsHV-1 and variants by all the World Organization for Animal Health (OIE) recommended diagnostic methods including polymerase chain reaction (PCR), quantitative PCR (qPCR), histology, in situ hybridization and confirmation using direct sequencing. The particular primers that target OsHV-1 and variants, including OsHV-1 microVar (μVar), were used in the PCR and qPCR. OsHV-1 μVar was detected in wild Mytilus spp. at C. gigas culture sites and more significantly the virus was detected in mussels at non-culture sites. Cohabitation of exposed wild mussels and naïve C. gigas resulted in viral transmission after 14 days, under an elevated temperature regime. These results indicate that mussels can harbour OsHV-1 μVar; however, the impact of OsHV-1 μVar on Mytilus spp. requires further investigation.

Functional analysis of Pacific oyster (Crassostrea gigas) β-thymosin: Focus on antimicrobial activity.

PubMed

Nam, Bo-Hye; Seo, Jung-Kil; Lee, Min Jeong; Kim, Young-Ok; Kim, Dong-Gyun; An, Cheul Min; Park, Nam Gyu

2015-07-01

An antimicrobial peptide, ∼5 kDa in size, was isolated and purified in its active form from the mantle of the Pacific oyster Crassostrea gigas by C18 reversed-phase high-performance liquid chromatography. Matrix-assisted laser desorption ionisation time-of-flight analysis revealed 4656.4 Da of the purified and unreduced peptide. A comparison of the N-terminal amino acid sequence of oyster antimicrobial peptide with deduced amino acid sequences in our local expressed sequence tag (EST) database of C. gigas (unpublished data) revealed that the oyster antimicrobial peptide sequence entirely matched the deduced amino acid sequence of an EST clone (HM-8_A04), which was highly homologous with the β-thymosin of other species. The cDNA possessed a 126-bp open reading frame that encoded a protein of 41 amino acids. To confirm the antimicrobial activity of C. gigas β-thymosin, we overexpressed a recombinant β-thymosin (rcgTβ) using a pET22 expression plasmid in an Escherichia coli system. The antimicrobial activity of rcgTβ was evaluated and demonstrated using a bacterial growth inhibition test in both liquid and solid cultures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microsatellite Analysis for Identification of Individuals Using Bone from the Extinct Steller's Sea Cow (Hydrodamalis gigas).

PubMed

Warner, Jeffery F; Harpole, Michael G; Crerar, Lorelei D

2017-01-01

Microsatellite DNA can provide more detailed population genetic information than mitochondrial DNA which is normally used to research ancient bone. The methods detailed in this chapter can be utilized for any type of bone. However, for this example, four microsatellite loci were isolated from Steller's sea cow (Hydrodamalis gigas) using published primers for manatee and dugong microsatellites. The primers DduC05 (Broderick et al., Mol Ecol Notes 6:1275-1277, 2007), Tmakb60, TmaSC5 (Pause et al., Mol Ecol Notes 6: 1073-1076, 2007), and TmaE11 (Garcia-Rodriguez et al., Mol Ecol 12:2161-2163, 2000) all successfully amplified microsatellites from H. gigas. The DNA samples were from bone collected on Bering or St. Lawrence Islands. DNA was analyzed using primers with the fluorescent label FAM-6. Sequenced alleles were then used to indicate a difference in the number of repeats and thus a difference in individuals. This is the first time that H. gigas microsatellite loci have been isolated. These techniques for ancient bone microsatellite analysis allow an estimate of population size for a newly discovered St. Lawrence Island sea cow population.

Identification of the Molecular Clockwork of the Oyster Crassostrea gigas

PubMed Central

Perrigault, Mickael; Tran, Damien

2017-01-01

Molecular clock system constitutes the origin of biological rhythms that allow organisms to anticipate cyclic environmental changes and adapt their behavior and physiology. Components of the molecular clock are largely conserved across a broad range of species but appreciable diversity in clock structure and function is also present especially in invertebrates. The present work aimed at identify and characterize molecular clockwork components in relationship with the monitoring of valve activity behavior in the oyster Crassostrea gigas. Results provided the characterization of most of canonical clock gene including clock, bmal/cycle, period, timeless, vertebrate-type cry, rev-erb, ror as well as other members of the cryptochrome/photolyase family (plant-like cry, 6–4 photolyase). Analyses of transcriptional variations of clock candidates in oysters exposed to light / dark regime and to constant darkness led to the generation of a putative and original clockwork model in C. gigas, intermediate of described systems in vertebrates and insects. This study is the first characterization of a mollusk clockwork. It constitutes essential bases to understand interactions of the different components of the molecular clock in C. gigas as well as the global mechanisms associated to the generation and the synchronization of biological rhythms in oysters. PMID:28072861

Interordinal gene capture, the phylogenetic position of Steller's sea cow based on molecular and morphological data, and the macroevolutionary history of Sirenia.

PubMed

Springer, Mark S; Signore, Anthony V; Paijmans, Johanna L A; Vélez-Juarbe, Jorge; Domning, Daryl P; Bauer, Cameron E; He, Kai; Crerar, Lorelei; Campos, Paula F; Murphy, William J; Meredith, Robert W; Gatesy, John; Willerslev, Eske; MacPhee, Ross D E; Hofreiter, Michael; Campbell, Kevin L

2015-10-01

The recently extinct (ca. 1768) Steller's sea cow (Hydrodamalis gigas) was a large, edentulous North Pacific sirenian. The phylogenetic affinities of this taxon to other members of this clade, living and extinct, are uncertain based on previous morphological and molecular studies. We employed hybridization capture methods and second generation sequencing technology to obtain >30kb of exon sequences from 26 nuclear genes for both H. gigas and Dugong dugon. We also obtained complete coding sequences for the tooth-related enamelin (ENAM) gene. Hybridization probes designed using dugong and manatee sequences were both highly effective in retrieving sequences from H. gigas (mean=98.8% coverage), as were more divergent probes for regions of ENAM (99.0% coverage) that were designed exclusively from a proboscidean (African elephant) and a hyracoid (Cape hyrax). New sequences were combined with available sequences for representatives of all other afrotherian orders. We also expanded a previously published morphological matrix for living and fossil Sirenia by adding both new taxa and nine new postcranial characters. Maximum likelihood and parsimony analyses of the molecular data provide robust support for an association of H. gigas and D. dugon to the exclusion of living trichechids (manatees). Parsimony analyses of the morphological data also support the inclusion of H. gigas in Dugongidae with D. dugon and fossil dugongids. Timetree analyses based on calibration density approaches with hard- and soft-bounded constraints suggest that H. gigas and D. dugon diverged in the Oligocene and that crown sirenians last shared a common ancestor in the Eocene. The coding sequence for the ENAM gene in H. gigas does not contain frameshift mutations or stop codons, but there is a transversion mutation (AG to CG) in the acceptor splice site of intron 2. This disruption in the edentulous Steller's sea cow is consistent with previous studies that have documented inactivating mutations in tooth-specific loci of a variety of edentulous and enamelless vertebrates including birds, turtles, aardvarks, pangolins, xenarthrans, and baleen whales. Further, branch-site dN/dS analyses provide evidence for positive selection in ENAM on the stem dugongid branch where extensive tooth reduction occurred, followed by neutral evolution on the Hydrodamalis branch. Finally, we present a synthetic evolutionary tree for living and fossil sirenians showing several key innovations in the history of this clade including character state changes that parallel those that occurred in the evolutionary history of cetaceans. Copyright © 2015 Elsevier Inc. All rights reserved.

Development of genomic microsatellite multiplex PCR using dye-labeled universal primer and its validation in pedigree analysis of Pacific oyster ( Crassostrea gigas)

NASA Astrophysics Data System (ADS)

Liu, Ting; Li, Qi; Song, Junlin; Yu, Hong

2017-02-01

There is an increasing requirement for traceability of aquaculture products, both for consumer protection and for food safety. There are high error rates in the conventional traceability systems depending on physical labels. Genetic traceability technique depending on DNA-based tracking system can overcome this problem. Genealogy information is essential for genetic traceability, and microsatellite DNA marker is a good choice for pedigree analysis. As increasing genotyping throughput of microsatellites, microsatellite multiplex PCR has become a fast and cost-effective technique. As a commercially important cultured aquatic species, Pacific oyster Crassostrea gigas has the highest global production. The objective of this study was to develop microsatellite multiplex PCR panels with dye-labeled universal primer for pedigree analysis in C. gigas, and these multiplex PCRs were validated using 12 full-sib families with known pedigrees. Here we developed six informative multiplex PCRs using 18 genomic microsatellites in C. gigas. Each multiplex panel contained a single universal primer M13(-21) used as a tail on each locus-specific forward primer and a single universal primer M13(-21) labeled with fluorophores. The polymorphisms of the markers were moderate, with an average of 10.3 alleles per locus and average polymorphic information content of 0.740. The observed heterozygosity per locus ranged from 0.492 to 0.822. Cervus simulations revealed that the six panels would still be of great value when massive families were analysed. Pedigree analysis of real offspring demonstrated that 100% of the offspring were unambiguously allocated to their parents when two multiplex PCRs were used. The six sets of multiplex PCRs can be an important tool for tracing cultured individuals, population genetic analysis, and selective breeding program in C. gigas.

Populations of Pacific oysters Crassostrea gigas respond variably to elevated CO2 and predation by Morula marginalba.

PubMed

Wright, John M; Parker, Laura M; O'Connor, Wayne A; Williams, Mark; Kube, Peter; Ross, Pauline M

2014-06-01

Ocean acidification is anticipated to decrease calcification and increase dissolution of shelled molluscs. Molluscs with thinner and weaker shells may be more susceptible to predation, but not all studies have measured negative responses of molluscs to elevated pCO2. Recent studies measuring the response of molluscs have found greater variability at the population level than first expected. Here we investigate the impact of acidification on the predatory whelk Morula marginalba and genetically distinct subpopulations of the Pacific oyster Crassostrea gigas. Whelks and eight family lines of C. gigas were separately exposed to ambient (385 ppm) and elevated (1000 ppm) pCO2 for 6 weeks. Following this period, individuals of M. marginalba were transferred into tanks with oysters at ambient and elevated pCO2 for 17 days. The increase in shell height of the oysters was on average 63% less at elevated compared to ambient pCO2. There were differences in shell compression strength, thickness, and mass among family lines of C. gigas, with sometimes an interaction between pCO2 and family line. Against expectations, this study found increased shell strength in the prey and reduced shell strength in the predator at elevated compared to ambient pCO2. After 10 days, the whelks consumed significantly more oysters regardless of whether C. gigas had been exposed to ambient or elevated CO2, but this was not dependent on the family line and the effect was not significant after 17 days. Our study found an increase in predation after exposure of the predator to predicted near-future levels of estuarine pCO2. © 2014 Marine Biological Laboratory.

Giga-z: A 100,000 Object Superconducting Spectrophotometer for LSST Follow-up

NASA Astrophysics Data System (ADS)

Marsden, Danica W.; Mazin, Benjamin A.; O'Brien, Kieran; Hirata, Chris

2013-09-01

We simulate the performance of a new type of instrument, a Superconducting Multi-Object Spectrograph (SuperMOS), that uses microwave kinetic inductance detectors (MKIDs). MKIDs, a new detector technology, feature good quantum efficiency in the UVOIR, can count individual photons with microsecond timing accuracy, and, like X-ray calorimeters, determine their energy to several percent. The performance of Giga-z, a SuperMOS designed for wide field imaging follow-up observations, is evaluated using simulated observations of the COSMOS mock catalog with an array of 100,000 R 423 nm = E/ΔE = 30 MKID pixels. We compare our results against a simultaneous simulation of LSST observations. In 3 yr on a dedicated 4 m class telescope, Giga-z could observe ≈2 billion galaxies, yielding a low-resolution spectral energy distribution spanning 350-1350 nm for each; 1000 times the number measured with any currently proposed LSST spectroscopic follow-up, at a fraction of the cost and time. Giga-z would provide redshifts for galaxies up to z ≈ 6 with magnitudes mi <~ 25, with accuracy σΔz/(1 + z) ≈ 0.03 for the whole sample, and σΔz/(1 + z) ≈ 0.007 for a select subset. We also find catastrophic failure rates and biases that are consistently lower than for LSST. The added constraint on dark energy parameters for WL + CMB by Giga-z using the FoMSWG default model is equivalent to multiplying the LSST Fisher matrix by a factor of α = 1.27 (wp ), 1.53 (wa ), or 1.98 (Δγ). This is equivalent to multiplying both the LSST coverage area and the training sets by α and reducing all systematics by a factor of 1/\\sqrt{\\alpha }, advantages that are robust to even more extreme models of intrinsic alignment.

Peering into peer-review at GigaScience.

PubMed

Edmunds, Scott C

2013-01-24

Fostering and promoting more open and transparent science is one of the goals of GigaScience. One of the ways we have been doing this is by throwing light on the peer-review process and carrying out open peer-review as standard. In this editorial, we provide our rationale for undertaking this policy, give examples of our positive experiences to date, and encourage others to open up the normally opaque publication process.

Relationship between single nucleotide polymorphism of glycogen synthase gene of Pacific oyster Crassostrea gigas and its glycogen content

NASA Astrophysics Data System (ADS)

Liu, Siwei; Li, Qi; Yu, Hong; Kong, Lingfeng

2017-02-01

Glycogen is important not only for the energy supplementary of oysters, but also for human consumption. High glycogen content can improve the stress survival of oyster. A key enzyme in glycogenesis is glycogen synthase that is encoded by glycogen synthase gene GYS. In this study, the relationship between single nucleotide polymorphisms (SNPs) in coding regions of Crassostrea gigas GYS (Cg-GYS) and individual glycogen content was investigated with 321 individuals from five full-sib families. Single-strand conformation polymorphism (SSCP) procedure was combined with sequencing to confirm individual SNP genotypes of Cg-GYS. Least-square analysis of variance was performed to assess the relationship of variation in glycogen content of C. gigas with single SNP genotype and SNP haplotype. As a consequence, six SNPs were found in coding regions to be significantly associated with glycogen content ( P < 0.01), from which we constructed four main haplotypes due to linkage disequilibrium. Furthermore, the most effective haplotype H2 (GAGGAT) had extremely significant relationship with high glycogen content ( P < 0.0001). These findings revealed the potential influence of Cg-GYS polymorphism on the glycogen content and provided molecular biological information for the selective breeding of good quality traits of C. gigas.

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.

Peering into peer-review at GigaScience

PubMed Central

2013-01-01

Fostering and promoting more open and transparent science is one of the goals of GigaScience. One of the ways we have been doing this is by throwing light on the peer-review process and carrying out open peer-review as standard. In this editorial, we provide our rationale for undertaking this policy, give examples of our positive experiences to date, and encourage others to open up the normally opaque publication process. PMID:23587291

Unique phagocytic properties of hemocytes of Pacific oyster Crassostrea gigas against yeast and yeast cell-wall derivatives.

PubMed

Takahashi, Keisuke G; Izumi-Nakajima, Nakako; Mori, Katsuyoshi

2017-11-01

For a marine bivalve mollusk such as Pacific oyster Crassostrea gigas, the elimination of foreign particles via hemocyte phagocytosis plays an important role in host defense mechanisms. The hemocytes of C. gigas have a high phagocytic ability for baker's yeast (Saccharomyces cerevisiae) and its cell-wall product zymosan. C. gigas hemocytes might phagocytose yeast cells after binding to polysaccharides on the cell-wall surface, but it is unknown how and what kinds of polysaccharide molecules are recognized. We conducted experiments to determine differences in the phagocytic ability of C. gigas hemocytes against heat-killed yeast (HK yeast), zymosan and zymocel, which are similarly sized and shaped but differ in the polysaccharide composition of their particle surface. We found that both the agranulocytes and granulocytes exerted strong phagocytic ability on all tested particles. The phagocytic index (PI) of granulocytes for zymosan was 9.4 ± 1.7, which significantly differed with that for HK yeast and zymocel (P < 0.05). To evaluate the PI for the three types of particles, and especially to understand the outcome of the much higher PI for zymosan, PI was gauged in increments of 5 (1-5, 6-10, 11-15, and ≥16), and the phagocytic frequencies were compared according to these increments. The results show that a markedly high PI of ≥16 was exhibited by 18.1% of granulocytes for zymosan, significantly higher than 1.7% and 3.9% shown for HK yeast and zymocel, respectively (P < 0.05). These findings indicate that the relatively high PI for zymosan could not be attributed to a situation wherein all phagocytic hemocytes shared a high mean PI, but rather to the ability of some hemocytes to phagocytose a larger portion of zymosan. To determine whether the phagocytosis of these respective particles depended on the recognition of specific polysaccharide receptors on the hemocyte surface, C. gigas hemocytes were pretreated with soluble α-mannan or β-laminarin and then allowed to phagocytose the three types of the particles. The percentage of phagocytic cells of β-laminarin-treated granulocytes decreased significantly for zymosan and zymocel, but not for yeast. These results suggest that C. gigas might possess at least two types of hemocytes, and that one type of the hemocytes (granulocytes) is more active for phagocytosis. The granulocytes were found to have multiple subtypes with different phagocytic abilities and multiple phagocytic receptors. Some of the granulocyte subtypes revealed a much stronger phagocytic ability, depending on the presence of β-glucan receptors for phagocytosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sclerochronology of Holocene oyster shells (Crassostrea gigas) from the West Coast of Bohai Sea, China

NASA Astrophysics Data System (ADS)

Fan, C.; Koeniger, P.; Wang, H.; Frechen, M.

2009-04-01

Sclerochronology, the study of periodic increments in skeletal organisms, can decipher the life history and environmental records preserved in fossil shells. Although there have been a number of studies that apply isotopic analyses to shells in open ocean and fresh water, investigations for brackish environments are rare. One of the common inhabitants in estuaries is the Crassostrea oyster. Kirby et al. (1998) demonstrated a close correspondence between the ligamental increments of convex and concave bands and yearly ^18O cycles; Andrus and Crowe (2000) found a close correspondence between translucent growth bands on the cross-section of the hinge and yearly ^18O cycles. They conclude that the morphological features on hinge and growth bands on the cross-section are formed annually and can be used to determine accurately age and growth rate in this species. However, Surge et al. (2001) could not find that these morphologic features have seasonal significance in the C. virginica shells. Therefore, these concave ridges are not reliable independent proxies of seasonality. These studies were carried out with C. virginica shells; none was studied with nature C. gigas, which was widely distributed along the Pacific coastal area. C. gigas has been introduced from its native home to all over the world, ranging from North America to Australia and Europe; it has become an important commercial harvest in many of these places. Buried Holocene oyster shells of C. gigas were sampled from a huge buried oyster reef on the West of Bohai Sea, China. One of these shells was selected for high resolution micro-sampling and stable isotope analyses testing the assumption that C. gigas ligamental increments are annual in nature. We analyzed 236 consecutive samples from the shell to show that morphologic features both on hinge and cross-section are annual by comparing them to the ^18O profiles. We tested the assumption that the morphologic features of C.gigas are delineated by convex tops and concave bottoms on hinge and corresponding translucent growth bands on cross-section. The shell has 13.5 ligamental increments, based on 13.5 convex bands and 13 concave bottoms on hinge. Convex tops correspond to ^18O minima (summers), whereas concave bottoms correspond to ^18O maxima, which were formed during the low temperature of winter in the study area. We demonstrate that the ligamental increments of convex tops, concave bottoms and translucent growth bands in the studied C. gigas shell are suitable indicators of annual growth increments. The life spans, growth rates, and the timing of death can be determined from the ligament increments and isotope profiles of buried oyster shells.

GigA and GigB are Master Regulators of Antibiotic Resistance, Stress Responses, and Virulence in Acinetobacter baumannii

PubMed Central

Shuman, Howard A.

2017-01-01

ABSTRACT A critical component of bacterial pathogenesis is the ability of an invading organism to sense and adapt to the harsh environment imposed by the host's immune system. This is especially important for opportunistic pathogens, such as Acinetobacter baumannii, a nutritionally versatile environmental organism that has recently gained attention as a life-threatening human pathogen. The emergence of A. baumannii is closely linked to antibiotic resistance, and many contemporary isolates are multidrug resistant (MDR). Unlike many other MDR pathogens, the molecular mechanisms underlying A. baumannii pathogenesis remain largely unknown. We report here the characterization of two recently identified virulence determinants, GigA and GigB, which comprise a signal transduction pathway required for surviving environmental stresses, causing infection and antibiotic resistance. Through transcriptome analysis, we show that GigA and GigB coordinately regulate the expression of many genes and are required for generating an appropriate transcriptional response during antibiotic exposure. Genetic and biochemical data demonstrate a direct link between GigA and GigB and the nitrogen phosphotransferase system (PTSNtr), establishing a novel connection between a novel stress response module and a well-conserved metabolic-sensing pathway. Based on the results presented here, we propose that GigA and GigB are master regulators of a global stress response in A. baumannii, and coupling this pathway with the PTSNtr allows A. baumannii to integrate cellular metabolic status with external environmental cues. IMPORTANCE Opportunistic pathogens, including Acinetobacter baumannii, encounter many harsh environments during the infection cycle, including antibiotic exposure and the hostile environment within a host. While the development of antibiotic resistance in A. baumannii has been well studied, how this organism senses and responds to environmental cues remain largely unknown. Herein, we investigate two previously identified virulence determinants, GigA and GigB, and report that they are required for in vitro stress resistance, likely comprising upstream elements of a global stress response pathway. Additional experiments identify a connection between GigA/GigB and a widely conserved metabolic-sensing pathway, the nitrogen phosphotransferase system. We propose that coordination of these two pathways allows A. baumannii to respond appropriately to changing environmental conditions, including those encountered during infection. PMID:28264991

GigA and GigB are Master Regulators of Antibiotic Resistance, Stress Responses, and Virulence in Acinetobacter baumannii.

PubMed

Gebhardt, Michael J; Shuman, Howard A

2017-05-15

A critical component of bacterial pathogenesis is the ability of an invading organism to sense and adapt to the harsh environment imposed by the host's immune system. This is especially important for opportunistic pathogens, such as Acinetobacter baumannii , a nutritionally versatile environmental organism that has recently gained attention as a life-threatening human pathogen. The emergence of A. baumannii is closely linked to antibiotic resistance, and many contemporary isolates are multidrug resistant (MDR). Unlike many other MDR pathogens, the molecular mechanisms underlying A. baumannii pathogenesis remain largely unknown. We report here the characterization of two recently identified virulence determinants, GigA and GigB, which comprise a signal transduction pathway required for surviving environmental stresses, causing infection and antibiotic resistance. Through transcriptome analysis, we show that GigA and GigB coordinately regulate the expression of many genes and are required for generating an appropriate transcriptional response during antibiotic exposure. Genetic and biochemical data demonstrate a direct link between GigA and GigB and the nitrogen phosphotransferase system (PTS Ntr ), establishing a novel connection between a novel stress response module and a well-conserved metabolic-sensing pathway. Based on the results presented here, we propose that GigA and GigB are master regulators of a global stress response in A. baumannii , and coupling this pathway with the PTS Ntr allows A. baumannii to integrate cellular metabolic status with external environmental cues. IMPORTANCE Opportunistic pathogens, including Acinetobacter baumannii , encounter many harsh environments during the infection cycle, including antibiotic exposure and the hostile environment within a host. While the development of antibiotic resistance in A. baumannii has been well studied, how this organism senses and responds to environmental cues remain largely unknown. Herein, we investigate two previously identified virulence determinants, GigA and GigB, and report that they are required for in vitro stress resistance, likely comprising upstream elements of a global stress response pathway. Additional experiments identify a connection between GigA/GigB and a widely conserved metabolic-sensing pathway, the nitrogen phosphotransferase system. We propose that coordination of these two pathways allows A. baumannii to respond appropriately to changing environmental conditions, including those encountered during infection. Copyright © 2017 American Society for Microbiology.

Purification and characterization of an oxygen-labile, NAD-dependent alcohol dehydrogenase from Desulfovibrio gigas.

PubMed Central

Hensgens, C M; Vonck, J; Van Beeumen, J; van Bruggen, E F; Hansen, T A

1993-01-01

A NAD-dependent, oxygen-labile alcohol dehydrogenase was purified from Desulfovibrio gigas. It was decameric, with subunits of M(r) 43,000. The best substrates were ethanol (Km, 0.15 mM) and 1-propanol (Km, 0.28 mM). N-terminal amino acid sequence analysis showed that the enzyme belongs to the same family of alcohol dehydrogenases as Zymomonas mobilis ADH2 and Bacillus methanolicus MDH. Images PMID:8491707

Gigas Sulci

NASA Image and Video Library

2016-11-03

Today's VIS image shows a small portion of Gigas Sulci. Located in the Tharsis region, these small linear ridges follow two trends at angle to each other, one toward the upper left corner and the other generally across from right to left. Small dunes are located between the ridges. The ridges were most likely formed by tectonic activity. Orbit Number: 65422 Latitude: 9.32915 Longitude: 231.265 Instrument: VIS Captured: 2016-09-12 16:56 http://photojournal.jpl.nasa.gov/catalog/PIA21157

Gonad Transcriptome Analysis of the Pacific Oyster Crassostrea gigas Identifies Potential Genes Regulating the Sex Determination and Differentiation Process.

PubMed

Yue, Chenyang; Li, Qi; Yu, Hong

2018-04-01

The Pacific oyster Crassostrea gigas is a commercially important bivalve in aquaculture worldwide. C. gigas has a fascinating sexual reproduction system consisting of dioecism, sex change, and occasional hermaphroditism, while knowledge of the molecular mechanisms of sex determination and differentiation is still limited. In this study, the transcriptomes of male and female gonads at different gametogenesis stages were characterized by RNA-seq. Hierarchical clustering based on genes differentially expressed revealed that 1269 genes were expressed specifically in female gonads and 817 genes were expressed increasingly over the course of spermatogenesis. Besides, we identified two and one gene modules related to female and male gonad development, respectively, using weighted gene correlation network analysis (WGCNA). Interestingly, GO and KEGG enrichment analysis showed that neurotransmitter-related terms were significantly enriched in genes related to ovary development, suggesting that the neurotransmitters were likely to regulate female sex differentiation. In addition, two hub genes related to testis development, lncRNA LOC105321313 and Cg-Sh3kbp1, and one hub gene related to ovary development, Cg-Malrd1-like, were firstly investigated. This study points out the role of neurotransmitter and non-coding RNA regulation during gonad development and produces lists of novel relevant candidate genes for further studies. All of these provided valuable information to understand the molecular mechanisms of C. gigas sex determination and differentiation.

Genetic variation assessed with microsatellites in mass selection lines of the Pacific oyster ( Crassostrea gigas) in China

NASA Astrophysics Data System (ADS)

Wang, Xubo; Li, Qi; Yu, Hong; Kong, Lingfeng

2016-12-01

Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding programs in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a relatively large number of broodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided important information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.

Cloning and expression patterns of two Smad genes during embryonic development and shell formation of the Pacific oyster Crassostrea gigas

NASA Astrophysics Data System (ADS)

Liu, Gang; Huan, Pin; Liu, Baozhong

2014-11-01

Increasing evidence indicates that transforming growth factor β (TGF-β) signaling pathways play many important roles in the early development of mollusks. However, limited information is known concerning their detailed mechanisms. Here, we describe the identification, cloning and characterization of two Smad genes, the key components of TGF-β signaling pathways, from the Pacific oyster Crassostrea gigas. Sequence analysis of the two genes, designated as cgi-smad1/ 5/ 8 and cgi-smad4, revealed conserved functional characteristics. The two genes were widely expressed in embryos and larvae, suggesting multiple roles in the early development of C. gigas. The mRNA of the two genes aggregated in the D quadrant and cgi-smad4 was highly expressed on the dorsal side of the gastrula, indicating that TGF-β signaling pathways may be involved in dorsoventral patterning in C. gigas. Furthermore, high expression levels of the two genes in the shell fields of embryos at different stages suggested important roles for TGF-β signaling pathways in particular phases of shell development, including the formation of the initial shell field and the biomineralization of larval shells. The results of this study provide fundamental support for elucidating how TGF-β signaling pathways participate in the early development of bivalve mollusks, and suggest that further work is warranted to this end.

Genome and Transcriptome Analyses Provide Insight into the Euryhaline Adaptation Mechanism of Crassostrea gigas

PubMed Central

Zhang, Linlin; Li, Chunyan; Li, Li; She, Zhicai; Huang, Baoyu; Zhang, Guofan

2013-01-01

Background The Pacific oyster, Crassostrea gigas, has developed special mechanisms to regulate its osmotic balance to adapt to fluctuations of salinities in coastal zones. To understand the oyster’s euryhaline adaptation, we analyzed salt stress effectors metabolism pathways under different salinities (salt 5, 10, 15, 20, 25, 30 and 40 for 7 days) using transcriptome data, physiology experiment and quantitative real-time PCR. Results Transcriptome data uncovered 189, 480, 207 and 80 marker genes for monitoring physiology status of oysters and the environment conditions. Three known salt stress effectors (involving ion channels, aquaporins and free amino acids) were examined. The analysis of ion channels and aquaporins indicated that 7 days long-term salt stress inhibited voltage-gated Na+/K+ channel and aquaporin but increased calcium-activated K+ channel and Ca2+ channel. As the most important category of osmotic stress effector, we analyzed the oyster FAAs metabolism pathways (including taurine, glycine, alanine, beta-alanine, proline and arginine) and explained FAAs functional mechanism for oyster low salinity adaptation. FAAs metabolism key enzyme genes displayed expression differentiation in low salinity adapted individuals comparing with control which further indicated that FAAs played important roles for oyster salinity adaptation. A global metabolic pathway analysis (iPath) of oyster expanded genes displayed a co-expansion of FAAs metabolism in C. gigas compared with seven other species, suggesting oyster’s powerful ability regarding FAAs metabolism, allowing it to adapt to fluctuating salinities, which may be one important mechanism underlying euryhaline adaption in oyster. Additionally, using transcriptome data analysis, we uncovered salt stress transduction networks in C. gigas. Conclusions Our results represented oyster salt stress effectors functional mechanisms under salt stress conditions and explained the expansion of FAAs metabolism pathways as the most important effectors for oyster euryhaline adaptation. This study was the first to explain oyster euryhaline adaptation at a genome-wide scale in C. gigas. PMID:23554902

New Insight for the Genetic Evaluation of Resistance to Ostreid Herpesvirus Infection, a Worldwide Disease, in Crassostrea gigas.

PubMed

Dégremont, Lionel; Lamy, Jean-Baptiste; Pépin, Jean-François; Travers, Marie-Agnès; Renault, Tristan

2015-01-01

The Pacific oyster, Crassostrea gigas, is the most important commercial oyster species cultivated in the world. Meanwhile, the ostreid herpesvirus 1 (OsHV-1) is one of the major pathogens affecting the Pacific oyster, and numerous mortality outbreaks related to this pathogen are now reported worldwide. To assess the genetic basis of resistance to OsHV-1 infection in spat C. gigas and to facilitate breeding programs for such a trait, if any exist, we compared the mortality of half- and full-sib families using three field methods and a controlled challenge by OsHV-1 in the laboratory. In the field, three methods were tested: (A) one family per bag; (B) one family per small soft mesh bag and all families inside one bag; (C) same as the previous methods but the oysters were individually labelled and then mixed. The mean mortality ranged from 80 to 82% and was related to OsHV-1 based on viral DNA detection. The narrow-sense heritability for mortality, and thus OsHV-1 resistance, ranged from 0.49 to 0.60. The high positive genetic correlations across the field methods suggested no genotype by environment interaction. Ideally, selective breeding could use method B, which is less time- and space-consuming. The narrow sense heritability for mortality under OsHV-1 challenge was 0.61, and genetic correlation between the field and the laboratory was ranged from 0.68 to 0.75, suggesting a weak genotype by environment interaction. Thus, most of families showing the highest survival performed well in field and laboratory conditions, and a similar trend was also observed for families with the lowest survival. In conclusion, this is the first study demonstrating a large additive genetic variation for resistance to OsHV-1 infection in C. gigas, regardless of the methods used, which should help in selective breeding to improve resistance to viral infection in C. gigas.

Development of a Medium Density Combined-Species SNP Array for Pacific and European Oysters (Crassostrea gigas and Ostrea edulis).

PubMed

Gutierrez, Alejandro P; Turner, Frances; Gharbi, Karim; Talbot, Richard; Lowe, Natalie R; Peñaloza, Carolina; McCullough, Mark; Prodöhl, Paulo A; Bean, Tim P; Houston, Ross D

2017-07-05

SNP arrays are enabling tools for high-resolution studies of the genetic basis of complex traits in farmed and wild animals. Oysters are of critical importance in many regions from both an ecological and economic perspective, and oyster aquaculture forms a key component of global food security. The aim of our study was to design a combined-species, medium density SNP array for Pacific oyster ( Crassostrea gigas ) and European flat oyster ( Ostrea edulis ), and to test the performance of this array on farmed and wild populations from multiple locations, with a focus on European populations. SNP discovery was carried out by whole-genome sequencing (WGS) of pooled genomic DNA samples from eight C. gigas populations, and restriction site-associated DNA sequencing (RAD-Seq) of 11 geographically diverse O. edulis populations. Nearly 12 million candidate SNPs were discovered and filtered based on several criteria, including preference for SNPs segregating in multiple populations and SNPs with monomorphic flanking regions. An Affymetrix Axiom Custom Array was created and tested on a diverse set of samples ( n = 219) showing ∼27 K high quality SNPs for C. gigas and ∼11 K high quality SNPs for O. edulis segregating in these populations. A high proportion of SNPs were segregating in each of the populations, and the array was used to detect population structure and levels of linkage disequilibrium (LD). Further testing of the array on three C. gigas nuclear families ( n = 165) revealed that the array can be used to clearly distinguish between both families based on identity-by-state (IBS) clustering parental assignment software. This medium density, combined-species array will be publicly available through Affymetrix, and will be applied for genome-wide association and evolutionary genetic studies, and for genomic selection in oyster breeding programs. Copyright © 2017 Gutierrez et al.

Giga-z: A 100,000 OBJECT SUPERCONDUCTING SPECTROPHOTOMETER FOR LSST FOLLOW-UP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marsden, Danica W.; Mazin, Benjamin A.; O'Brien, Kieran

2013-09-15

We simulate the performance of a new type of instrument, a Superconducting Multi-Object Spectrograph (SuperMOS), that uses microwave kinetic inductance detectors (MKIDs). MKIDs, a new detector technology, feature good quantum efficiency in the UVOIR, can count individual photons with microsecond timing accuracy, and, like X-ray calorimeters, determine their energy to several percent. The performance of Giga-z, a SuperMOS designed for wide field imaging follow-up observations, is evaluated using simulated observations of the COSMOS mock catalog with an array of 100,000 R{sub 423{sub nm}} = E/{Delta}E = 30 MKID pixels. We compare our results against a simultaneous simulation of LSST observations.more » In 3 yr on a dedicated 4 m class telescope, Giga-z could observe Almost-Equal-To 2 billion galaxies, yielding a low-resolution spectral energy distribution spanning 350-1350 nm for each; 1000 times the number measured with any currently proposed LSST spectroscopic follow-up, at a fraction of the cost and time. Giga-z would provide redshifts for galaxies up to z Almost-Equal-To 6 with magnitudes m{sub i} {approx}< 25, with accuracy {sigma}{sub {Delta}z/(1+z)} Almost-Equal-To 0.03 for the whole sample, and {sigma}{sub {Delta}z/(1+z)} Almost-Equal-To 0.007 for a select subset. We also find catastrophic failure rates and biases that are consistently lower than for LSST. The added constraint on dark energy parameters for WL + CMB by Giga-z using the FoMSWG default model is equivalent to multiplying the LSST Fisher matrix by a factor of {alpha} = 1.27 (w{sub p} ), 1.53 (w{sub a} ), or 1.98 ({Delta}{gamma}). This is equivalent to multiplying both the LSST coverage area and the training sets by {alpha} and reducing all systematics by a factor of 1/{radical}({alpha}), advantages that are robust to even more extreme models of intrinsic alignment.« less

Results and insights from the NCSU Insect Museum GigaPan project

PubMed Central

Bertone, Matthew A.; Blinn, Robert L.; Dew1, Tanner M. StanfieldKelly J.; Seltmann, Katja C.; Deans, Andrew R.

2012-01-01

Abstract Pinned insect specimens stored in museum collections are a fragile and valuable resource for entomological research. As such, they are usually kept away from viewing by the public and hard to access by experts. Here we present a method for mass imaging insect specimens, using GigaPan technology to achieve highly explorable, many-megapixel panoramas of insect museum drawers. We discuss the advantages and limitations of the system, and describe future avenues of collections research using this technology. PMID:22859883

Antiviral Defense and Innate Immune Memory in the Oyster.

PubMed

Green, Timothy J; Speck, Peter

2018-03-16

The Pacific oyster, Crassostrea gigas , is becoming a valuable model for investigating antiviral defense in the Lophotrochozoa superphylum. In the past five years, improvements to laboratory-based experimental infection protocols using Ostreid herpesvirus I (OsHV-1) from naturally infected C. gigas combined with next-generation sequencing techniques has revealed that oysters have a complex antiviral response involving the activation of all major innate immune pathways. Experimental evidence indicates C. gigas utilizes an interferon-like response to limit OsHV-1 replication and spread. Oysters injected with a viral mimic (polyI:C) develop resistance to OsHV-1. Improved survival following polyI:C injection was found later in life (within-generational immune priming) and in the next generation (multi-generational immune priming). These studies indicate that the oyster's antiviral defense system exhibits a form of innate immune-memory. An important priority is to identify the molecular mechanisms responsible for this phenomenon. This knowledge will motivate the development of practical and cost-effective treatments for improving oyster health in aquaculture.

Identification and Functional Characterization of the Glycogen Synthesis Related Gene Glycogenin in Pacific Oysters (Crassostrea gigas).

PubMed

Li, Busu; Meng, Jie; Li, Li; Liu, Sheng; Wang, Ting; Zhang, Guofan

2017-09-06

High glycogen levels in the Pacific oyster (Crassostrea gigas) contribute to its flavor, quality, and hardiness. Glycogenin (CgGN) is the priming glucosyltransferase that initiates glycogen biosynthesis. We characterized the full sequence and function of C. gigas CgGN. Three CgGN isoforms (CgGN-α, β, and γ) containing alternative exon regions were isolated. CgGN expression varied seasonally in the adductor muscle and gonadal area and was the highest in the adductor muscle. Autoglycosylation of CgGN can interact with glycogen synthase (CgGS) to complete glycogen synthesis. Subcellular localization analysis showed that CgGN isoforms and CgGS were located in the cytoplasm. Additionally, a site-directed mutagenesis experiment revealed that the Tyr200Phe and Tyr202Phe mutations could affect CgGN autoglycosylation. This is the first study of glycogenin function in marine bivalves. These findings will improve our understanding of glycogen synthesis and accumulation mechanisms in mollusks. The data are potentially useful for breeding high-glycogen oysters.

Facilitated giga-seal formation with a just originated glass surface.

PubMed

Böhle, T; Benndorf, K

1994-07-01

A simple technique of tip preparation in patch pipettes is described, which facilitates giga-seal formation. The pipettes were fabricated from thick-walled borosilicate glass tubing (external diameter 2.0 mm, internal diameter 0.5 mm) and the tips could be repeatedly broken in the bath. The pipette resistance correspondingly fell in steps of 3-20 M omega from about 80 M omega to about 2 M omega (double concentrated Tyrode). Scanning electron microscopy showed that the tip obtained after breaking was fairly plain. These broken tips were especially appropriate for patch-clamping. In cardiac myocytes in 11 out of 26 patches with Na+ channel activity, giga-seals developed spontaneously, i.e. without suction. In these patches the amplitude of the mean current with depolarizing pulses to -40 mV was significantly higher in comparison with patches formed under negative pressure. It is concluded that spontaneously sealed patches are most likely of planar configuration and the Na+ channel activity exceeds that in suction-induced patches.

Genetics of the Steller's Sea Cow (Hydrodamalis gigas): A Study of Ancient Bone Material

NASA Astrophysics Data System (ADS)

Crerar, Lorelei D.

Georg Wilhelm Steller was born 100 years before Darwin in 1709 and he was part of a vast exploration fifty years before Lewis and Clark explored America. Steller was important to the study of marine mammals because he was the only naturalist to see and describe the great northern sea cow ( Hydrodamalis gigas). Knowledge of an extinct population can be used to aid the conservation of a current population. Extraction of DNA from this extinct animal was performed in order to determine the population structure of the Steller's sea cow. A test was also developed that can definitively state whether or not a random bone sample came from H. gigas. This test could be used by the Fish and Wildlife Service (FWS) and the National Oceanic and Atmospheric Administration (NOAA) to examine material distributed in the North Pacific to determine whether samples are legally traded extinct Steller's sea cow or illegally traded extant marine mammal species protected under the Marine Mammal Protection Act (MMPA).

In situ distribution and characterization of the organic content of the oyster shell Crassostrea gigas (Mollusca, Bivalvia).

PubMed

Dauphin, Yannicke; Ball, Alexander D; Castillo-Michel, Hiram; Chevallard, Corinne; Cuif, Jean-Pierre; Farre, Bastien; Pouvreau, Stéphane; Salomé, Murielle

2013-01-01

Cultivation of commercial oysters is now facing the possible influence of global change in sea water composition, commonly referred to as "ocean acidification". In order to test the potential consequence of the predicted environmental changes, a cultivation experiment was carried out. The left and right valves of the oyster shell Crassostrea gigas differ in their structure; moreover, lenses of non compact layers are irregular. The shell layers of juvenile C. gigas are studied using a variety of highly spatially resolved techniques to establish their composition and structure. Our results confirm the presence of three different calcitic structural types. The role of the lenses of chalky layers is not yet deciplered. Despite a common mineralogy, the elemental composition of the layers differs. The sulphur aminoacids and sulphated polysaccharide contents of the intracrystalline and intercrystalline matrices differ, as well as those of the structural types. The possible different sensitivity of these structures to environmental changes is still unknown. Copyright © 2012 Elsevier Ltd. All rights reserved.

Roles of HynAB and Ech, the Only Two Hydrogenases Found in the Model Sulfate Reducer Desulfovibrio gigas

PubMed Central

Morais-Silva, Fabio O.; Santos, Catia I.; Rodrigues, Rute

2013-01-01

Sulfate-reducing bacteria are characterized by a high number of hydrogenases, which have been proposed to contribute to the overall energy metabolism of the cell, but exactly in what role is not clear. Desulfovibrio spp. can produce or consume H2 when growing on organic or inorganic substrates in the presence or absence of sulfate. Because of the presence of only two hydrogenases encoded in its genome, the periplasmic HynAB and cytoplasmic Ech hydrogenases, Desulfovibrio gigas is an excellent model organism for investigation of the specific function of each of these enzymes during growth. In this study, we analyzed the physiological response to the deletion of the genes that encode the two hydrogenases in D. gigas, through the generation of ΔechBC and ΔhynAB single mutant strains. These strains were analyzed for the ability to grow on different substrates, such as lactate, pyruvate, and hydrogen, under respiratory and fermentative conditions. Furthermore, the expression of both hydrogenase genes in the three strains studied was assessed through quantitative reverse transcription-PCR. The results demonstrate that neither hydrogenase is essential for growth on lactate-sulfate, indicating that hydrogen cycling is not indispensable. In addition, the periplasmic HynAB enzyme has a bifunctional activity and is required for growth on H2 or by fermentation of pyruvate. Therefore, this enzyme seems to play a dominant role in D. gigas hydrogen metabolism. PMID:23974026

Detection of ostreid herpesvirus 1 microvariant DNA in aquatic invertebrate species, sediment and other samples collected from the Georges River estuary, New South Wales, Australia.

PubMed

Evans, Olivia; Paul-Pont, Ika; Whittington, Richard J

2017-01-24

Ostreid herpesvirus 1 microvariants (OsHV-1) present a serious threat to the Australian Crassostrea gigas industry. Of great concern is the propensity for mortality due to the virus recurring each season in farmed oysters. However, the source of the virus in recurrent outbreaks remains unclear. Reference strain ostreid herpesvirus 1 (OsHV-1 ref) and other related variants have been detected in several aquatic invertebrate species other than C. gigas in Europe, Asia and the USA. The aim of this study was to confirm the presence or absence of OsHV-1 in a range of opportunistically sampled aquatic invertebrate species inhabiting specific locations within the Georges River estuary in New South Wales, Australia. OsHV-1 DNA was detected in samples of wild C. gigas, Saccostrea glomerata, Anadara trapezia, mussels (Mytilus spp., Trichomya hirsuta), whelks (Batillaria australis or Pyrazus ebeninus) and barnacles Balanus spp. collected from several sites between October 2012 and April 2013. Viral loads in non-ostreid species were consistently low, as was the prevalence of OsHV-1 DNA detection. Viral concentrations were highest in wild C. gigas and S. glomerata; the prevalence of detectable OsHV-1 DNA in these oysters reached approximately 68 and 43%, respectively, at least once during the study. These species may be important to the transmission and/or persistence of OsHV-1 in endemically infected Australian estuaries.

The final spawning ground of Tachypleus gigas (Müller, 1785) on the east Peninsular Malaysia is at risk: a call for action.

PubMed

Nelson, Bryan Raveen; Satyanarayana, Behara; Moh, Julia Hwei Zhong; Ikhwanuddin, Mhd; Chatterji, Anil; Shaharom, Faizah

2016-01-01

Tanjung Selongor and Pantai Balok (State Pahang) are the only two places known for spawning activity of the Malaysian horseshoe crab - Tachypleus gigas (Müller, 1785) on the east coast of Peninsular Malaysia. While the former beach has been disturbed by several anthropogenic activities that ultimately brought an end to the spawning activity of T. gigas, the status of the latter remains uncertain. In the present study, the spawning behavior of T. gigas at Pantai Balok (Sites I-III) was observed over a period of thirty six months, in three phases, between 2009 and 2013. Every year, the crab's nesting activity was found to be high during Southwest monsoon (May-September) followed by Northeast (November-March) and Inter monsoon (April and October) periods. In the meantime, the number of female T. gigas in 2009-2010 (Phase-1) was higher (38 crabs) than in 2010-2011 (Phase-2: 7 crabs) and 2012-2013 (Phase-3: 9 crabs) for which both increased overexploitation (for edible and fishmeal preparations) as well as anthropogenic disturbances in the vicinity (sand mining since 2009, land reclamation for wave breaker/parking lot constructions in 2011 and fishing jetty construction in 2013) are responsible. In this context, the physical infrastructure developments have altered the sediment close to nesting sites to be dominated by fine sand (2.5Xφ ) with moderately-well sorted (0.6-0.7σφ), very-coarse skewed (-2.4SKφ), and extremely leptokurtic (12.6Kφ) properties. Also, increased concentrations of Cadmium (from 4.2 to 13.6 mg kg(-1)) and Selenium (from 11.5 to 23.3 mg kg(-1)) in the sediment, and Sulphide (from 21 to 28 µg l(-1)) in the water were observed. In relation to the monsoonal changes affecting sheltered beach topography and sediment flux, the spawning crabs have shown a seasonal nest shifting behaviour in-between Sites I-III during 2009-2011. However, in 2012-2013, the crabs were mostly restricted to the areas (i.e., Sites I and II) with high oxygen (5.5-8.0 mg l(-1)) and moisture depth (6.2-10.2 cm). In view of the sustained anthropogenic pressure on the coastal habitats on one hand and decreasing horseshoe crabs population on the other, it is crucial to implement both conservation and management measures for T. gigas at Pantai Balok. Failing that may lead to the loss of this final spawning ground on the east coast of P. Malaysia.

Systems Harmonization and Convergence - the GIGAS Approach

NASA Astrophysics Data System (ADS)

Marchetti, P. G.; Biancalana, A.; Coene, Y.; Uslander, T.

2009-04-01

0.1 Background The GIGAS1 Support Action promotes the coherent and interoperable development of the GMES, INSPIRE and GEOSS initiatives through their concerted adoption of standards, protocols, and open architectures. 0.2 Preparing for Coordinated Data Access The GMES Coordinated Data Access System is under design and implementation2. This objective has motivated the definition of the interoperability standards between the contributing missions. The following elements have been addressed with associated papers submitted to OGC: The EO Product Metadata has been based on the OGC Geographic Markup Language, addressing sensor characteristics for optical, radar and atmospheric products. Collection and service discovery: an ISO extension package for CSW ebRim has been proposed. Catalogue Service (CSW): an Earth Observation extension package of the CSW ebRim has been proposed. Feasibility Analysis and Order: an Order interface control document and an Earth Observation profile of the Sensor Planning Service have been proposed. Online Data Access: an Earth Observation profile of the Web Map Services (WMS) for visualization and evaluation purposes has been proposed. Identity (user) management: the objective in the long term is to allow for a single sign-on to the Coordinated Data Access system by users registered in the various Earth Observation ground segments by providing a federated identity across participating ground segments, exploiting OASIS standards. 0.3 The GIGAS proposed harmonization approach The approach proposed by GIGAS is based on three elements: Technology watch Comparative analysis Shaping of initiatives and standards This paper concentrates on the methodology for technology watch and comparative analysis. The complexity of the GIGAS scenario involving huge systems (i.e. GEOSS, INSPIRE, GMES etc.) entails the interaction with different heterogeneous partners, each with a specific competence, expertise and know-how. 0.3.1 Technology watch The methodology proposed is based on an RM-ODP based study supported by interoperability use cases and scenarios used to derive requirements. GIGAS will monitor the INSPIRE, GMES and GEOSS evolution and analyze the requirements, the standards, the services and the architecture, the models, the processes and the consensus mechanisms with the same elements of the other systems under analysis. activities in the fields of standard development that are part of the three initiatives. This task will provide the basis for how these three initiatives will strategically support consensus and efficient standards development going forward. architecture, specifications, innovative concepts and software developments of past or ongoing FP6/FP7 research topics. The use of an RM-ODP approach is selected as: most of the architectural approaches to be compared are based on RM-ODP, it supports distributed processing, it aims at fostering interoperability across heterogeneous systems, it tries to hide distribution to systems developers. However, as most of the systems to be considered have the characteristic of a loosely-coupled network of systems and services instead of a "distributed processing system based on interacting objects", the RM-ODP concepts are tailored for the GIGAS needs. The usage of RM-ODP for GIGAS Requirements and Technology Watch is two-fold: Architectural analysis: It is performed for all projects and initiatives. Its purpose is to identify possibilities but also major obstacles for interoperability. Furthermore, it identifies the major use cases to be analysed in more detail. Use Case Implementation Analysis: It is used to describe how selected use cases of the projects and initiatives are implemented in the different architectures. Its purpose is to identify technological gaps and concrete problems of interoperability. It is performed only for selected use cases. The output of the Technology Watch is an RM-ODP based report containing parallel analysis on the same aspects on the three initiatives integrated by analysis of relevant FP6-FP7 projects and standardization activities. 0.3.2 Comparative Analysis Based on the outcomes of the previous monitoring tasks, GIGAS undertakes a comparative analysis on solutions, requirements, architecture, models, processes and consensus mechanisms used by INSPIRE, GMES and GEOSS, taking into account the inputs from the monitoring of FP6/FP7 research projects and the ongoing standardization activities. Initiative Contact Points will insure that the overall policy framework and schedules for each of the three initiatives will be factored in. The result of the Comparative Analysis includes: A list of recommendations to GEOSS, INSPIRE and GMES to be expanded and processed in depth in the following shaping phase The identification of technological gaps to be explored in the following shaping phase. Guidelines and objectives for the architectural approach within GIGAS Analysis on the schedules of the three initiatives and on the FP6/FP7 programs and standardization activities, with identification of key milestones or intervention points.

Evidence of neutralizing activity against T3 coliphage in oyster Crassostrea gigas hemolymph.

PubMed

Bachère, E; Hervio, D; Mialhe, E; Grizel, H

1990-01-01

To investigate defense reactions of bivalve molluscs against viruses, experimental in vitro assays have been developed using T3 coliphage as a test virus. A native neutralizing factor in oyster Crassostrea gigas serum showed high individual variability and was enhanced significantly by repeated sampling of hemolymph from the same oysters. The responsible factor is apparently thermolabile and sensitive to EDTA treatment. Because of an inhibitory effect by the enzymatic inhibitor, phenylmethylsulphonyl fluoride (PMSF), the T3-neutralizing factor may be related to serine protease.

NATIVE PLANTS FOR OPTIMIZING CARBON SEQUESTRATION IN RECLAIMED LANDS

DOE Office of Scientific and Technical Information (OSTI.GOV)

P. UNKEFER; M. EBINGER; ET AL

Carbon emissions and atmospheric concentrations are expected to continue to increase through the next century unless major changes are made in the way carbon is managed. Managing carbon has emerged as a pressing national energy and environmental need that will drive national policies and treaties through the coming decades. Addressing carbon management is now a major priority for DOE and the nation. One way to manage carbon is to use energy more efficiently to reduce our need for major energy and carbon source-fossil fuel combustion. Another way is to increase our use of low-carbon and carbon free fuels and technologies.more » A third way, and the focus of this proposal, is carbon sequestration, in which carbon is captured and stored thereby mitigating carbon emissions. Sequestration of carbon in the terrestrial biosphere has emerged as the principle means by which the US will meet its near-term international and economic requirements for reducing net carbon emissions (DOE Carbon Sequestration: State of the Science. 1999; IGBP 1998). Terrestrial carbon sequestration provides three major advantages. First, terrestrial carbon pools and fluxes are of sufficient magnitude to effectively mitigate national and even global carbon emissions. The terrestrial biosphere stores {approximately}2060 GigaTons of carbon and transfers approximately 120 GigaTons of carbon per year between the atmosphere and the earth's surface, whereas the current global annual emissions are about 6 GigaTons. Second, we can rapidly and readily modify existing management practices to increase carbon sequestration in our extensive forest, range, and croplands. Third, increasing soil carbon is without negative environment consequences and indeed positively impacts land productivity. The terrestrial carbon cycle is dependent on several interrelationships between plants and soils. Because the soil carbon pool ({approximately}1500 Giga Tons) is approximately three times that in terrestrial vegetation ({approximately}560 GigaTons), the principal focus of terrestrial sequestration efforts is to increase soil carbon. But soil carbon ultimately derives from vegetation and therefore must be managed indirectly through aboveground management of vegetation and nutrients. Hence, the response of whole ecosystems must be considered in terrestrial carbon sequestration strategies.« less

Comparative sensitivity of Crassostrea angulata and Crassostrea gigas embryo-larval development to As under varying salinity and temperature.

PubMed

Moreira, Anthony; Figueira, Etelvina; Libralato, Giovanni; Soares, Amadeu M V M; Guida, Marco; Freitas, Rosa

2018-06-07

Oysters are a diverse group of marine bivalves that inhabit coastal systems of the world's oceans, providing a variety of ecosystem services, and represent a major socioeconomic resource. However, oyster reefs have become inevitably impacted from habitat destruction, overfishing, pollution and disease outbreaks that have pushed these structures to the break of extinction. In addition, the increased frequency of climate change related events promise to further challenge oyster species survival worldwide. Oysters' early embryonic development is likely the most vulnerable stage to climate change related stressors (e.g. salinity and temperature shifts) as well as to pollutants (e.g. arsenic), and therefore can represent the most important bottleneck that define populations' survival in a changing environment. In light of this, the present study aimed to assess two important oyster species, Crassostrea angulata and Crassostrea gigas embryo-larval development, under combinations of salinity (20, 26 and 33), temperature (20, 24 and 28 °C) and arsenic (As) exposure (0, 30, 60, 120, 240, 480, 960 and 1920 μg. As L -1 ), to infer on different oyster species capacity to cope with these environmental stressors under the eminent threat of climate change and increase of pollution worldwide. Results showed differences in each species range of salinity and temperature for successful embryonic development. For C angulata, embryo-larval development was successful at a narrower range of both salinity and temperature, compared to C. gigas. Overall, As induced higher toxicity to C. angulata embryos, with calculated EC50 values at least an order of magnitude lower than those calculated for C. gigas. The toxicity of As (measured as median effective concentration, EC50) showed to be influenced by both salinity and temperature in both species. Nonetheless, salinity had a greater influence on embryos' sensitivity to As. This pattern was mostly noticed for C. gigas, with lower salinity inducing higher sensitivity to As. Results were discussed considering the existing literature and suggest that C. angulata populations are likely to become more vulnerable under near future predictions for temperature rise, salinity shifts and pollution. Copyright © 2018 Elsevier Ltd. All rights reserved.

Proteomic and metabolomic responses of Pacific oyster Crassostrea gigas to elevated pCO2 exposure.

PubMed

Wei, Lei; Wang, Qing; Wu, Huifeng; Ji, Chenglong; Zhao, Jianmin

2015-01-01

The gradually increased atmospheric CO2 partial pressure (pCO2) has thrown the carbonate chemistry off balance and resulted in decreased seawater pH in marine ecosystem, termed ocean acidification (OA). Anthropogenic OA is postulated to affect the physiology of many marine calcifying organisms. However, the susceptibility and metabolic pathways of change in most calcifying animals are still far from being well understood. In this work, the effects of exposure to elevated pCO2 were characterized in gills and hepatopancreas of Crassostrea gigas using integrated proteomic and metabolomic approaches. Metabolic responses indicated that high CO2 exposure mainly caused disturbances in energy metabolism and osmotic regulation marked by differentially altered ATP, glucose, glycogen, amino acids and organic osmolytes in oysters, and the depletions of ATP in gills and the accumulations of ATP, glucose and glycogen in hepatopancreas accounted for the difference in energy distribution between these two tissues. Proteomic responses suggested that OA could not only affect energy and primary metabolisms, stress responses and calcium homeostasis in both tissues, but also influence the nucleotide metabolism in gills and cytoskeleton structure in hepatopancreas. This study demonstrated that the combination of proteomics and metabolomics could provide an insightful view into the effects of OA on oyster C. gigas. The gradually increased atmospheric CO2 partial pressure (pCO2) has thrown the carbonate chemistry off balance and resulted in decreased seawater pH in marine ecosystem, termed ocean acidification (OA). Anthropogenic OA is postulated to affect the physiology of many marine calcifying organisms. However, the susceptibility and metabolic pathways of change in most calcifying animals are still far from being understood. To our knowledge, few studies have focused on the responses induced by pCO2 at both protein and metabolite levels. The pacific oyster C. gigas, widely distributed throughout most of the world's oceans, is a model organism for marine environmental science. In the present study, an integrated metabolomic and proteomic approach was used to elucidate the effects of ocean acidification on Pacific oyster C. gigas, hopefully shedding light on the physiological responses of marine mollusk to the OA stress. Copyright © 2014 Elsevier B.V. All rights reserved.

Estimates of Heritability for Growth and Shell Color Traits and Their Genetic Correlations in the Black Shell Strain of Pacific Oyster Crassostrea gigas.

PubMed

Xu, Lan; Li, Qi; Yu, Hong; Kong, Lingfeng

2017-10-01

The Pacific oyster Crassostrea gigas has been introduced widely and massively and became an economically important aquaculture species on a global scale. We estimated heritabilities of growth and shell color traits and their genetic correlations in black shell strain of C. gigas. Analyses were performed on 22 full-sib families in a nested mating design including 410 individuals at harvest (24 months of age). The parentage assignment was inferred based on four panels of multiplex PCR markers including 10 microsatellite loci and 94.9% of the offspring were unambiguously assigned to single parent pairs. The Spearman correlation test (r = - 0.992, P < 0.001) demonstrated the high consistency of the shell pigmentation (SP) and L* and their same efficacy in shell color measurements. The narrow-sense heritability estimated under the animal model analysis was 0.18 ± 0.12 for shell height, 0.25 ± 0.16 for shell length, 0.10 ± 0.09 for shell width, 0.42 ± 0.20 for total weight, 0.32 ± 0.18 for shell weight, and 0.68 ± 0.16 for L*, 0.69 ± 0.16 for shell pigmentation, respectively. The considerable additive genetic variation in growth and shell color traits will make it feasible to produce genetic improvements for these traits in selective breeding program. High genetic and phenotypic correlations were found among growth traits and among shell color traits. To optimize a selection strategy for both fast growth and pure dark shell strain of C. gigas, it is proposed to take both total weight and black shell as joint objective traits in selective breeding program. Our study offers an important reference in the process of selective breeding in black shell color stain of C. gigas and will facilitate to develop favorable breeding strategies of genetic improvements for this economically important strain.

Gigapixel imaging as a resource for geoscience teaching, research, and outreach

NASA Astrophysics Data System (ADS)

Bentley, C.; Pitts, A.; Rohrback, R. C.; Dudek, M.

2015-12-01

The Mid-Atlantic Geo-Image Collection is a repository of gigapixel-resolution geologic imagery intended as a tool for geoscience professionals, educators, students, & researchers (http://gigapan.com/groups/100/galleries). GigaPan provides a unique combination of context & detail, with images that maintain a high level of resolution through every level of magnification. Using geological GigaPans, physically disabled students can participate in virtual field trips, instructors can bring inaccessible outcrops into the classroom, & students can zoom in on hand samples without expensive microscopes. Because GigaPan images permit detailed visual examination of geologic, MAGIC is particularly suitable for use in online geology courses. The images are free to use and tag. Our 10 contributors (3 faculty, 2 graduate students, & 6 undergraduates) use 4 models of mobile robot cameras (outcrop/landscape), 2 laboratory-based GIGAmacro imaging systems (hand samples) & 2 experimental units: 1 for thin sections, 1 for GigaPans of scanning electron microscopy. Each of these has strengths & weaknesses. MAGIC has suites of images of Appalachian structure & stratigraphy, Rocky Mountains, Snowball Earth hypothesis, & doomed outcrops of Miocene strata on Chesapeake Bay. Virtual field trips with our imagery have been developed for: Billy Goat Trail, MD; Helen Lake, AB; Wind River Canyon, WY; the Canadian Rockies; El Paso, TX; glaciation around the world; and Corridor H, WV (a GSA field trip in Nov. 2015). Virtual sample sets have been developed for introductory minerals, igneous, sedimentary, & metamorphic rocks, the stratigraphy of VA's physiographic provinces, & the Snowball Earth hypothesis. The virtual field trips have been tested in both online & onsite courses. There are close to a thousand images in the collection, each averaging about 0.9 gigapixels in size, with close to 900,000 views total. A new viewer for GigaPans was released this year by GIGAmacro. This new viewer allows measurement and calibration, automatically resizing scale bars, side-by-side comparisons between 2 images, overlapping presentation of 2 images, & annotation by users. Comparative viewers are particularly useful for the presentation of before/after imagery; raw vs. annotated imagery, & polarized views of thin sections.

Oocyte maturation and origin of the germline as revealed by the expression of Nanos-like in the Pacific oyster Crassostrea gigas.

PubMed

Xu, Rui; Li, Qi; Yu, Hong; Kong, Lingfeng

2018-04-13

Nanos gene plays an important role in germline development in animals. However, the molecular mechanisms involved in germline development in Mollusca, the second largest animal phylum, are still poorly understood. Here we identified the Nanos orthologue from the Pacific oyster Crassostrea gigas (Cg-Nanos-like), and investigated the expression patterns of Nanos during gametogenesis and embryogenesis in C. gigas. Tissue expression analysis showed that Cg-Nanos-like was specifically expressed in female gonads. During the reproductive cycle, the expression of Cg-Nanos-like mRNA increased matching the seasonal development of the ovarian tissues in diploids, while the expression levels were significantly lower in the ovaries of sterile triploids compared to diploids. High expression of Cg-Nanos-like transcripts were detected in early embryonic stages, while the expression significantly dropped at gastrulation and was barely detectable in veliger stages. In situ hybridization showed that Cg-Nanos-like was expressed at different stages of developing oocytes, whereas positive signals were detected only in spermatogonia during the spermatogenic cycle. These findings indicated that Cg-Nanos-like was involved in the development of germ cells, and maintenance of oocyte maturation. In early embryogenesis, the transcripts were broadly expressed; following gastrulation, the expression was restricted to two cell clumps, which might be the putative primordial germ cells (PGCs) or their precursors. Based on the results, the formation of the PGCs in C. gigas was consistent with the model of transition from epigenesis to preformation. Copyright © 2017. Published by Elsevier B.V.

Causes and effects of a highly successful marine invasion: Case-study of the introduced Pacific oyster Crassostrea gigas in continental NW European estuaries

NASA Astrophysics Data System (ADS)

Troost, Karin

2010-10-01

Since the 1960's, the Pacific oyster Crassostrea gigas has been introduced for mariculture at several locations within NW Europe. The oyster established itself everywhere and expanded rapidly throughout the receiving ecosystems, forming extensive and dense reef structures. It became clear that the Pacific oyster induced major changes in NW European estuaries. This paper reviews the causes of the Pacific oyster's remarkably successful establishment and spread in The Netherlands and neighbouring countries, and includes a comprehensive review of consequences for the receiving communities. Ecosystem engineering by C. gigas and a relative lack of natural enemies in receiving ecosystems are identified as the most important characteristics facilitating the invader's successful establishment and expansion. The Pacific oyster's large filtration capacity and eco-engineering characteristics induced many changes in receiving ecosystems. Different estuaries are affected differently; in the Dutch Oosterschelde estuary expanding stocks saturate the carrying capacity whereas in the Wadden Sea no such problems exist. In general, the Pacific oyster seems to fit well within continental NW European estuarine ecosystems and there is no evidence that the invader outcompetes native bivalves. C. gigas induces changes in plankton composition, habitat heterogeneity and biodiversity, carrying capacity, food webs and parasite life cycles. The case of the Pacific oyster in NW European estuaries is only one example in an increasing series of biological invasions mediated by human activities. This case-study will contribute to further elucidating general mechanisms in marine invasions; invasions that sometimes appear a threat, but can also contribute to ecological complexity.

Temperature, energy metabolism, and adaptive divergence in two oyster subspecies.

PubMed

Li, Ao; Li, Li; Song, Kai; Wang, Wei; Zhang, Guofan

2017-08-01

Comparisons of related species that have diverse spatial distributions provide an efficient way to investigate adaptive evolution in face of increasing global warming. The oyster subjected to high environmental selections is a model species as sessile marine invertebrate. This study aimed to detect the adaptive divergence of energy metabolism in two oyster subspecies from the genus Crassostrea - C. gigas gigas and C. gigas angulata -which are broadly distributed along the northern and southern coasts of China, respectively. We examined the effects of acute thermal stress on energy metabolism in two oyster subspecies after being common gardened for one generation in identical conditions. Thermal responses were assessed by incorporating physiological, molecular, and genomic approaches. Southern oysters exhibited higher fluctuations in metabolic rate, activities of key energetic enzymes, and levels of thermally induced gene expression than northern oysters. For genes involved in energy metabolism, the former displayed higher basal levels of gene expression and a more pronounced downregulation of thermally induced expression, while the later exhibited lower basal levels and a less pronounced downregulation of gene expression. Contrary expression pattern was observed in oxidative stress gene. Besides, energy metabolic tradeoffs were detected in both subspecies. Furthermore, the genetic divergence of a nonsynonymous SNP ( SOD-132 ) and five synonymous SNPs in other genes was identified and validated in these two subspecies, which possibly affects downstream functions and explains the aforementioned phenotypic variations. Our study demonstrates that differentiations in energy metabolism underlie the plasticity of adaptive divergence in two oyster subspecies and suggest C. gigas angulata with moderate phenotypic plasticity has higher adaptive potential to cope with exacerbated global warming.

Warm temperature acclimation impacts metabolism of paralytic shellfish toxins from Alexandrium minutum in commercial oysters.

PubMed

Farrell, Hazel; Seebacher, Frank; O'Connor, Wayne; Zammit, Anthony; Harwood, D Tim; Murray, Shauna

2015-09-01

Species of Alexandrium produce potent neurotoxins termed paralytic shellfish toxins and are expanding their ranges worldwide, concurrent with increases in sea surface temperature. The metabolism of molluscs is temperature dependent, and increases in ocean temperature may influence both the abundance and distribution of Alexandrium and the dynamics of toxin uptake and depuration in shellfish. Here, we conducted a large-scale study of the effect of temperature on the uptake and depuration of paralytic shellfish toxins in three commercial oysters (Saccostrea glomerata and diploid and triploid Crassostrea gigas, n = 252 per species/ploidy level). Oysters were acclimated to two constant temperatures, reflecting current and predicted climate scenarios (22 and 27 °C), and fed a diet including the paralytic shellfish toxin-producing species Alexandrium minutum. While the oysters fed on A. minutum in similar quantities, concentrations of the toxin analogue GTX1,4 were significantly lower in warm-acclimated S. glomerata and diploid C. gigas after 12 days. Following exposure to A. minutum, toxicity of triploid C. gigas was not affected by temperature. Generally, detoxification rates were reduced in warm-acclimated oysters. The routine metabolism of the oysters was not affected by the toxins, but a significant effect was found at a cellular level in diploid C. gigas. The increasing incidences of Alexandrium blooms worldwide are a challenge for shellfish food safety regulation. Our findings indicate that rising ocean temperatures may reduce paralytic shellfish toxin accumulation in two of the three oyster types; however, they may persist for longer periods in oyster tissue. © 2015 John Wiley & Sons Ltd.

Exploitable Lipids and Fatty Acids in the Invasive Oyster Crassostrea gigas on the French Atlantic Coast

PubMed Central

Dagorn, Flore; Couzinet-Mossion, Aurélie; Kendel, Melha; Beninger, Peter G.; Rabesaotra, Vony; Barnathan, Gilles; Wielgosz-Collin, Gaëtane

2016-01-01

Economic exploitation is one means to offset the cost of controlling invasive species, such as the introduced Pacific oyster (Crassostrea gigas Thunberg) on the French Atlantic coast. Total lipid and phospholipid (PL) fatty acids (FAs) and sterols were examined in an invasive population of C. gigas in Bourgneuf Bay, France, over four successive seasons, with a view to identify possible sources of exploitable substances. The total lipid level (% dry weight) varied from 7.1% (winter) to 8.6% (spring). Of this, PLs accounted for 28.1% (spring) to 50.4% (winter). Phosphatidylcholine was the dominant PL throughout the year (up to 74% of total PLs in winter). Plasmalogens were identified throughout the year as a series of eleven dimethylacetals (DMAs) with chain lengths between C16 and C20 (up to 14.5% of PL FAs + DMAs in winter). Thirty-seven FAs were identified in the PL FAs. Eicosapentaenoic acid (20:5n-3 EPA/7.53% to 14.5%) and docosahexaenoic acid (22:6n-3 DHA/5.51% to 9.5%) were the dominant polyunsaturated FAs in all seasons. Two non-methylene-interrupted dienoic (NMID) FAs were identified in all seasons: 7,13-docosadienoic and 7,15-docosadienoic acids, the latter being present at relatively high levels (up to 9.6% in winter). Twenty free sterols were identified, including cholesterol at 29.9% of the sterol mixture and about 33% of phytosterols. C. gigas tissues thus contained exploitable lipids for health benefits or as a potential source of high-quality commercial lecithin. PMID:27231919

Sequence Analysis, Kinetic Constants, and Anion Inhibition Profile of the Nacrein-Like Protein (CgiNAP2X1) from the Pacific Oyster Magallana gigas (Ex-Crassostrea gigas).

PubMed

Perfetto, Rosa; Del Prete, Sonia; Vullo, Daniela; Sansone, Giovanni; Barone, Carmela M A; Rossi, Mosè; Supuran, Claudiu T; Capasso, Clemente

2017-08-28

The carbonic anhydrase (CA, EC 4.2.1.1) superfamily of metalloenzymes catalyzes the hydration of carbon dioxide to bicarbonate and protons. The catalytically active form of these enzymes incorporates a metal hydroxide derivative, the formation of which is the rate-determining step of catalytic reaction, being affected by the transfer of a proton from a metal-coordinated water molecule to the environment. Here, we report the cloning, expression, and purification of a particular CA, i.e., nacrein-like protein encoded in the genome of the Pacific oyster Magallana gigas (previously known as Crassostrea gigas ). Furthermore, the amino acid sequence, kinetic constants, and anion inhibition profile of the recombinant enzyme were investigated for the first time. The new protein, CgiNAP2X1, is highly effective as catalyst for the CO₂ hydration reaction, based on the measured kinetic parameters, i.e., k cat = 1.0 × 10⁶ s -1 and k cat / K M = 1.2 × 10⁸ M -1 ·s -1 . CgiNAP2X1 has a putative signal peptide, which probably allows an extracellular localization of the protein. The inhibition data demonstrated that the best anion inhibitors of CgiNAP2X1 were diethyldithiocarbamate, sulfamide, sulfamate, phenylboronic acid and phenylarsonic acid, which showed a micromolar affinity for this enzyme, with K I s in the range of 76-87 μM. These studies may add new information on the physiological role of the molluskan CAs in the biocalcification processes.

Bioaccumulation of trace metals in farmed pacific oysters Crassostrea gigas from SW Gulf of California coast, Mexico.

PubMed

Jonathan, M P; Muñoz-Sevilla, N P; Góngora-Gómez, Andrés Martin; Luna Varela, Raquel Gabriela; Sujitha, S B; Escobedo-Urías, D C; Rodríguez-Espinosa, P F; Campos Villegas, Lorena Elizabeth

2017-11-01

The aim of the study was to evaluate the bioavailability of trace metals (Chromium, Copper, Nickel, Lead, Zinc, Cadmium, Arsenic, and Mercury) in the commercially consumed Crassostrea gigas oysters collected over a 12-month growth period (2011-12) from an experimental cultivation farm in La Pitahaya, Sinaloa State, Mexico. Sediment and water samples were also collected from four different zones adjacent to the cultivation area to identify the concentration patterns of metals. The results revealed that sewage disposals, fertilizers used for agricultural practices and shrimp culture are the major sources for the enrichment of certain toxic metals. The metal concentrations in oysters presented a decreasing order of abundance (all values in mg Kg -1 ): Zn (278.91 ± 93.03) > Cu (63.13 ± 31.72) > Cr (22.29 ± 30.23) > Cd (14.54 ± 4.28) > Ni (9.41 ± 11.33) > Pb (2.22 ± 1.33) > As (0.58 ± 0.91) > Hg (0.04 ± 0.06). Bioconcentration Factor (BCF) and Biota Sediment Accumulation Factor (BSAF) exhibited that C. gigas in the region are strong accumulators for Zn and Cd respectively. Thus, the present study proves to fulfill the gap in understanding the rate of bioaccumulation of metals in C. gigas which is regarded as the most sought after oyster species globally. Copyright © 2017 Elsevier Ltd. All rights reserved.

Low Genetic Diversity and Structuring of the Arapaima (Osteoglossiformes, Arapaimidae) Population of the Araguaia-Tocantins Basin.

PubMed

Vitorino, Carla A; Nogueira, Fabrícia; Souza, Issakar L; Araripe, Juliana; Venere, Paulo C

2017-01-01

The arapaima, Arapaima gigas , is a fish whose populations are threatened by both overfishing and the ongoing destruction of its natural habitats. In the Amazon basin, varying levels of population structure have been found in A. gigas , although no data are available on the genetic diversity or structure of the populations found in the Araguaia-Tocantins basin, which has a topographic profile, hydrological regime, and history of fishing quite distinct from those of the Amazon. In this context, microsatellite markers were used to assess the genetic diversity and connectivity of five wild A. gigas populations in the Araguaia-Tocantins basin. The results of the analysis indicated low levels of genetic diversity in comparison with other A. gigas populations, studied in the Amazon basin. The AMOVA revealed that the Arapaima populations of the Araguaia-Tocantins basin are structured significantly. No correlation was found between pairwise F ST values and the geographical distance among populations. The low level of genetic variability and the evidence of restricted gene flow may both be accounted for by overfishing, as well as the other human impacts that these populations have been exposed to over the years. The genetic fragility of these populations demands attention, given that future environmental changes (natural or otherwise) may further reduce these indices and eventually endanger these populations. The results of this study emphasize the need to take the genetic differences among the study populations into account when planning management measures and conservation strategies for the arapaima stocks of the Araguaia-Tocantins basin.

Low Genetic Diversity and Structuring of the Arapaima (Osteoglossiformes, Arapaimidae) Population of the Araguaia-Tocantins Basin

PubMed Central

Vitorino, Carla A.; Nogueira, Fabrícia; Souza, Issakar L.; Araripe, Juliana; Venere, Paulo C.

2017-01-01

The arapaima, Arapaima gigas, is a fish whose populations are threatened by both overfishing and the ongoing destruction of its natural habitats. In the Amazon basin, varying levels of population structure have been found in A. gigas, although no data are available on the genetic diversity or structure of the populations found in the Araguaia-Tocantins basin, which has a topographic profile, hydrological regime, and history of fishing quite distinct from those of the Amazon. In this context, microsatellite markers were used to assess the genetic diversity and connectivity of five wild A. gigas populations in the Araguaia-Tocantins basin. The results of the analysis indicated low levels of genetic diversity in comparison with other A. gigas populations, studied in the Amazon basin. The AMOVA revealed that the Arapaima populations of the Araguaia-Tocantins basin are structured significantly. No correlation was found between pairwise FST values and the geographical distance among populations. The low level of genetic variability and the evidence of restricted gene flow may both be accounted for by overfishing, as well as the other human impacts that these populations have been exposed to over the years. The genetic fragility of these populations demands attention, given that future environmental changes (natural or otherwise) may further reduce these indices and eventually endanger these populations. The results of this study emphasize the need to take the genetic differences among the study populations into account when planning management measures and conservation strategies for the arapaima stocks of the Araguaia-Tocantins basin. PMID:29114261

The Extracellular Metalloprotease of Vibrio tubiashii Is a Major Virulence Factor for Pacific Oyster (Crassostrea gigas) Larvae▿

PubMed Central

Hasegawa, Hiroaki; Lind, Erin J.; Boin, Markus A.; Häse, Claudia C.

2008-01-01

Vibrio tubiashii is a recently reemerging pathogen of larval bivalve mollusks, causing both toxigenic and invasive disease. Marine Vibrio spp. produce an array of extracellular products as potential pathogenicity factors. Culture supernatants of V. tubiashii have been shown to be toxic to oyster larvae and were reported to contain a metalloprotease and a cytolysin/hemolysin. However, the structural genes responsible for these proteins have yet to be identified, and it is uncertain which extracellular products play a role in pathogenicity. We investigated the effects of the metalloprotease and hemolysin secreted by V. tubiashii on its ability to kill Pacific oyster (Crassostrea gigas) larvae. While V. tubiashii supernatants treated with metalloprotease inhibitors severely reduced the toxicity to oyster larvae, inhibition of the hemolytic activity did not affect larval toxicity. We identified structural genes of V. tubiashii encoding a metalloprotease (vtpA) and a hemolysin (vthA). Sequence analyses revealed that VtpA shared high homology with metalloproteases from a variety of Vibrio species, while VthA showed high homology only to the cytolysin/hemolysin of Vibrio vulnificus. Compared to the wild-type strain, a VtpA mutant of V. tubiashii not only produced reduced amounts of protease but also showed decreased toxicity to C. gigas larvae. Vibrio cholerae strains carrying the vtpA or vthA gene successfully secreted the heterologous protein. Culture supernatants of V. cholerae carrying vtpA but not vthA were highly toxic to Pacific oyster larvae. Together, these results suggest that the V. tubiashii extracellular metalloprotease is important in its pathogenicity to C. gigas larvae. PMID:18456850

Burst mode PCS of EPON

NASA Astrophysics Data System (ADS)

Du, Xiao

2005-02-01

Normal GIGA ETHERNET continuously transmits or receives 8B/10B codes including data codes, idle codes or configuration information. In ETHERNET network, one computer links one port of switch through CAT5 and that is OK. But for EPON, it is different. All ONUs share one fiber in upstream, if we inherit the GIGA ETHERNET PHY, then collision will occur. All ONUs always transmit 8B/10B codes, and the optical signal will overlay. The OLT will receive the fault information. So we need a novel EPON PHY instead of ETHERNET PHY. But its major function is compatible with ETHERNET"s. In this article, first, the function of PCS sub layer is discussed and a novel PCS module is given that can be used in not only EPON system but also in GIGA ETHERNET system. The design of PCS is based on 1000BASE-X PCS technology. And the function of 1000BASE-X PCS should be accomplished first. Next we modify the design in order to meet the requirements of EPON system. In the new design, the auto negotiation and synchronization is the same to the 1000 BASE-X technology.

Rising water temperatures, reproduction and recruitment of an invasive oyster, Crassostrea gigas, on the French Atlantic coast.

PubMed

Dutertre, Mickaël; Beninger, Peter G; Barillé, Laurent; Papin, Mathias; Haure, Joël

2010-02-01

The recent appearance and invasion of feral oysters (Crassostrea gigas) along the northern European Atlantic coast, underscores the necessity to investigate the relationship between environmental variables, reproductive physiology, larval development and recruitment. We studied these relationships at both high (HT) and intermediate (IT) - turbidity sites, through historical data on water temperatures, multi-parameter environmental probes, histological analyses, and field collections of planktonic larvae and settled post-larvae in 2005 and 2006. A progressive warming trend was observed, especially since 1995, when oyster proliferation first became severe. Threshold temperatures for oocyte growth, larval development and settlement were achieved in both 2005 and 2006. The HT site showed greater numbers of larvae and post-larvae than the IT site for both years, with the highest numbers of post-larvae observed at both sites during the warmer summer of 2006. These results suggest that increased temperatures in northern European waters allow successful reproduction, larval development, and recruitment of C. gigas. High turbidity conditions further enhance this success. 2009 Elsevier Ltd. All rights reserved.

The Making of NASA's Global Selfie: 100+ Countries, Thousands of Photos

NASA Image and Video Library

2014-05-22

The 3.2 gigapixel Global Selfie mosaic, hosted by GigaPan, was made with 36,422 individual images that were posted to social media sites on or around Earth Day, April 22, 2014. Zoom in and find yours here: 1.usa.gov/SnR7ki Credit: NASA The 3.2 gigapixel Global Selfie mosaic, hosted by GigaPan, was made with 36,422 individual images that were posted to social media sites on or around Earth Day, April 22, 2014. Zoom in and find yours here: 1.usa.gov/SnR7ki

Rapid and inexpensive analysis of genetic variability in Arapaima gigas by PCR multiplex panel of eight microsatellites.

PubMed

Hamoy, I G; Santos, E J M; Santos, S E B

2008-01-22

The aim of the present study was the development of a multiplex genotyping panel of eight microsatellite markers of Arapaima gigas, previously described. Specific primer pairs were developed, each one of them marked with either FAM-6, HEX or NED. The amplification conditions using the new primers were standardized for a single reaction. The results obtained demonstrate high heterozygosity (average of 0.69) in a Lower Amazon population. The multiplex system described can thus be considered a fast, efficient and inexpensive method for the investigation of genetic variability in Arapaima populations.

The Giga Bit Transceiver based Expandable Front-End (GEFE)—a new radiation tolerant acquisition system for beam instrumentation

NASA Astrophysics Data System (ADS)

Barros Marin, M.; Boccardi, A.; Donat Godichal, C.; Gonzalez, J. L.; Lefevre, T.; Levens, T.; Szuk, B.

2016-02-01

The Giga Bit Transceiver based Expandable Front-End (GEFE) is a multi-purpose FPGA-based radiation tolerant card. It is foreseen to be the new standard FMC carrier for digital front-end applications in the CERN BE-BI group. Its intended use ranges from fast data acquisition systems to slow control installed close to the beamlines, in a radioactive environment exposed to total ionizing doses of up to 750 Gy. This paper introduces the architecture of the GEFE, its features as well as examples of its application in different setups.

The final spawning ground of Tachypleus gigas (Müller, 1785) on the east Peninsular Malaysia is at risk: a call for action

PubMed Central

Moh, Julia Hwei Zhong; Ikhwanuddin, Mhd; Chatterji, Anil; Shaharom, Faizah

2016-01-01

Tanjung Selongor and Pantai Balok (State Pahang) are the only two places known for spawning activity of the Malaysian horseshoe crab - Tachypleus gigas (Müller, 1785) on the east coast of Peninsular Malaysia. While the former beach has been disturbed by several anthropogenic activities that ultimately brought an end to the spawning activity of T. gigas, the status of the latter remains uncertain. In the present study, the spawning behavior of T. gigas at Pantai Balok (Sites I-III) was observed over a period of thirty six months, in three phases, between 2009 and 2013. Every year, the crab’s nesting activity was found to be high during Southwest monsoon (May–September) followed by Northeast (November–March) and Inter monsoon (April and October) periods. In the meantime, the number of female T. gigas in 2009–2010 (Phase-1) was higher (38 crabs) than in 2010–2011 (Phase-2: 7 crabs) and 2012–2013 (Phase-3: 9 crabs) for which both increased overexploitation (for edible and fishmeal preparations) as well as anthropogenic disturbances in the vicinity (sand mining since 2009, land reclamation for wave breaker/parking lot constructions in 2011 and fishing jetty construction in 2013) are responsible. In this context, the physical infrastructure developments have altered the sediment close to nesting sites to be dominated by fine sand (2.5Xφ ) with moderately-well sorted (0.6–0.7σφ), very-coarse skewed (−2.4SKφ), and extremely leptokurtic (12.6Kφ) properties. Also, increased concentrations of Cadmium (from 4.2 to 13.6 mg kg−1) and Selenium (from 11.5 to 23.3 mg kg−1) in the sediment, and Sulphide (from 21 to 28 µg l−1) in the water were observed. In relation to the monsoonal changes affecting sheltered beach topography and sediment flux, the spawning crabs have shown a seasonal nest shifting behaviour in-between Sites I-III during 2009–2011. However, in 2012–2013, the crabs were mostly restricted to the areas (i.e., Sites I and II) with high oxygen (5.5–8.0 mg l−1) and moisture depth (6.2–10.2 cm). In view of the sustained anthropogenic pressure on the coastal habitats on one hand and decreasing horseshoe crabs population on the other, it is crucial to implement both conservation and management measures for T. gigas at Pantai Balok. Failing that may lead to the loss of this final spawning ground on the east coast of P. Malaysia. PMID:27547542

Enhancement of pheochromocytoma nerve cell growth by consecutive fractionization of Angelica gigas Nakai extracts

PubMed Central

Jeong, Myoung Hoon; Kim, Ji Seon; Zou, Yunyun; Yoon, Chang Soon; Lim, Hye Won; Ahn, Juhee

2010-01-01

This work was to investigate the effect of flavonoids from Angelica gigas Nakai on the proliferation and differentiation of PC12 cells. Several solvents including hexane, chloroform, ethyl acetate, butanol and water consecutively partitioned. We determined the ethanol crude extract of Angelica gigas Nakai. The hexane fraction was shown to contain the highest number of flavonoids as follows; 21.48 mg/g and the composition of the flavonoids was as follows: 12.24 mg/g of quercetin, 4.39 mg/g of myricetin and 2.58 mg/g of catechin. In addition, this hexane fraction greatly increased both cell growth and outgrowth of the neurite, and whose effects were three times higher than those of the other fractions. The length of the neurites was measured as ca. 110 μm in adding 50 μg/mL of the hexane fraction, which was about the same as the case of adding 50 ng/mL of NGF as a positive control. This result indicates that the differentiation of PC12 cells by the addition of the hexane fraction was comparable to the case of adding NGF. The hexane fraction was also determined to prevent apoptosis of PC12 cells by suppressing DNA fragmentation. It is interesting that the mixture of three major flavonoids, quercetin, myricetin and catechin showed stronger activity on, both PC12 cell growth and neuritis outgrowth, than when adding each flavonoid alone. We believe this was due to the synergistic effects of the three flavonoids. The activities of these flavonoids from Angelica gigas Nakai are reported for the first time in this study. PMID:20936343

Transcriptomic Responses to Salinity Stress in the Pacific Oyster Crassostrea gigas

PubMed Central

Zhao, Xuelin; Yu, Hong; Kong, Lingfeng; Li, Qi

2012-01-01

Background Low salinity is one of the main factors limiting the distribution and survival of marine species. As a euryhaline species, the Pacific oyster Crassostrea gigas is considered to be tolerant to relative low salinity. The genes that regulate C. gigas responses to osmotic stress were monitored using the next-generation sequencing of whole transcriptome with samples taken from gills. By RNAseq technology, transcript catalogs of up- and down-regulated genes were generated from the oysters exposed to low and optimal salinity seawater. Methodology/Principal Findings Through Illumina sequencing, we reported 1665 up-regulated transcripts and 1815 down-regulated transcripts. A total of 45771 protein-coding contigs were identified from two groups based on sequence similarities with known proteins. As determined by GO annotation and KEGG pathway mapping, functional annotation of the genes recovered diverse biological functions and processes. The genes that changed expression significantly were highly represented in cellular process and regulation of biological process, intracellular and cell, binding and protein binding according to GO annotation. The results highlighted genes related to osmoregulation, signaling and interactions of osmotic stress response, anti-apoptotic reactions as well as immune response, cell adhesion and communication, cytoskeleton and cell cycle. Conclusions/Significance Through more than 1.5 million sequence reads and the expression data of the two libraries, the study provided some useful insights into signal transduction pathways in oysters and offered a number of candidate genes as potential markers of tolerance to hypoosmotic stress for oysters. In addition, the characterization of C. gigas transcriptome will not only provide a better understanding of the molecular mechanisms about the response to osmotic stress of the oysters, but also facilitate research into biological processes to find underlying physiological adaptations to hypoosmotic shock for marine invertebrates. PMID:23029449

Use of nanoindentation technique for a better understanding of the fracture toughness of Strombus gigas conch shell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romana, L., E-mail: laurence.romana@univ-ag.fr; Thomas, P.; Bilas, P.

2013-02-15

In this work the nanochemical properties of the composite organomineral biomaterial constituting Strombus gigas conch shell are studied by means of dynamic mechanical analyses associated to nanoidentation technique. The measurements are performed on shell samples presenting different surface orientations relative to the growth axis of the conch shell. The influence of the organic component of the biomaterial on its nanomechanical properties is also investigated by studying fresh and dried S. gigas conch shells. Monocrystalline aragonite is used as a reference. For the understanding of nanochemical behaviour, special attention is paid to the pop in events observed on the load/displacement curvesmore » which results from nanofractures' initiation and propagation occuring during the load process. In order to better understand the mechanical properties systematic studies of the structure and morphology are performed using scanning electron microscopy, atomic force microscopy and X-ray diffractometry. The hardness and Young's modulus values measured on bio aragonite samples are close to those of the aragonite mineral standard. This surprising result shows that, H and E values are not related to the bio composition and lamellar structure of the bio aragonite. However, it was found that the organic layer and the micro architecture strongly influence the nanofracture initiation and propagation processes in the samples. Statistic study of the pop-in events can help to predict the macroscopic mechanical behaviour of the material. - Highlights: ► Nanomechanical properties of Strombus gigas conch shell ► Low influence of the crossed lamellar structure on H and E values at the nano scale ► Strong influence of the crossed lamellar on nanocracks initiation ► Correlation between mechanical behaviors at the macro and nano scales.« less

Morphology of the larval shell of three oyster species of the genus Crassostrea Sacco, 1897 (Bivalvia: Ostreidae).

PubMed

Christo, S W; Absher, T M; Boehs, G

2010-08-01

In this study we describe the morphology of the larval shell of three oyster species of Crassostrea genus. Two species, C. rhizophorae and C. brasiliana, are native to the Brazilian coast, and C. gigas is an introduced species. Samples of laboratory reared larvae, obtained through artificial fertilisation, were collected at intervals during the cultivation process for analysis using Scanning Electron Microscopy (SEM). Prodissoconch morphology was observed in relation to the presence, position, form and number of teeth in the three larval stages: D-shaped larva, umbo larva and pediveliger. Characteristic of D-shaped larvae of C. rhizophorae was the total absence of teeth in the provinculum area while C. brasiliana and C. gigas had two anterior and two posterior teeth in each valve. In the umbo larval phase, the three species had the same number of teeth in each valve: two posterior and two anterior teeth in the right valve and three posterior and three anterior in the left valve. In the pediveliger stage the three species could be differentiated by the number of anterior teeth of the right valve: C. rhizophorae had two teeth, C. brasiliana one tooth and C. gigas three teeth.

Cytochemical investigation of the digestive gland of two strombidae species (Strombus gigas and Strombus pugilis) in relation to the nutrition.

PubMed

Volland, Jean-Marie; Gros, Olivier

2012-10-01

Strombus gigas and Strombus pugilis are threatened species and aquaculture represents a good alternative solution to the fishing. In this study, we highlighted the intracellular digestion process in the digestive gland of two Strombidae species, S. gigas and Strombuspugilis, by the cytochemical characterization of two lysosomal enzymes: acid phosphatase and arylsulfatase. In order to check the efficiency of artificial food digestion, we conducted the characterization on freshly collected, starved and artificially fed individuals of S. pugilis. TEM observations of digestive gland sections from freshly collected individuals of both species revealed the presence of acid phosphatase and arylsulfatase activity mostly located in the apical third of digestive cells. Both enzymes were also detected in artificially fed individuals. In response to the starvation, acid phosphatase is not produced anymore by digestive cells, while arylsulfatase is still present. To our knowledge, this is the first cytochemical validation of intracellular digestion of artificial food in Strombidae. This study highlights the intracellular digestion of artificial food developed for Strombidae aquaculture. Moreover, we have shown that the lysosomal activity could be used as a feed index. Copyright © 2012 Wiley Periodicals, Inc.

The Rehbinder effect in iron during giga-cycle fatigue loading

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bannikov, M. V., E-mail: mbannikov@icmm.ru; Naimark, O. B.

The influence of the adsorptive strength reduction effect (the Rehbinder effect) on the fatigue life of pure iron under the giga-cycle loading regime was investigated. Specimens were loaded by an ultrasonic testing machine with a frequency of 20 kHz in air and in contact with eutectic alloy of gallium with tin and indium. A significant (by several orders of magnitude) worsening of the life-time of iron in contact with a molten metal as compared with tests in air was established. The liquid metal penetrates into the material to a depth of 200 μm to the center of a fatigue crack. Themore » mechanism of the fatigue crack initiation in the giga-cycle regime of loading in contact with a surfactant is differing: the crack is formed on the surface of the specimen rather than within it as is the case for air. Based on the electron and optical microscopy data for the fracture surface, it can be concluded that exactly the change in the crack initiation mechanism reduces the fatigue life of iron in contact with a liquid metal because the initiated crack propagates regardless of the surfactant.« less

Mineral and water content of A. gigas scales determine local micromechanical properties and energy dissipation mechanisms

NASA Astrophysics Data System (ADS)

Troncoso, Omar P.; Gigos, Florian; Torres, Fernando G.

2017-11-01

Arapaima gigas scales are natural laminated composite materials made of individual layers with different degrees of mineralization, accompanied of varying mechanical properties. This natural design provides scales with hardness and flexibility, and can serve as a source of inspiration for the development of new layered composites with a hard surface and flexible base. In this paper, we have carried out cyclic micro-indentation tests on both; the internal and the highly mineralized external surface of air dried and wet scales, in order to assess the variation of their local micromechanical properties with regard to the mineral and water content. The load-penetration (P-h) curves showed that creep takes place throughout the application of a constant force during the micro-indentation tests, confirming the time dependent response of A. gigas scales. A model that accounted for the elastic, plastic and viscous responses of the samples was used to fit the experimental results. The penetration depth during loading and creep, as well as the energy dissipated are dependent on the water content. The used model suggests that the viscous response of the internal layer increases with the water content.

Morphometric partitioning of the respiratory surface area and diffusion capacity of the gills and swim bladder in juvenile Amazonian air-breathing fish, Arapaima gigas.

PubMed

Fernandes, Marisa Narciso; da Cruz, André Luis; da Costa, Oscar Tadeu Ferreira; Perry, Steven Franklin

2012-09-01

The gills and the respiratory swim bladders of juvenile specimens (mean body mass 100g) of the basal teleost Arapaima gigas (Cuvier 1829) were evaluated using stereological methods in vertical sections. The surface areas, harmonic mean barrier thicknesses and morphometric diffusing capacities for oxygen and carbon dioxide were estimated. The average respiratory surface area of the swim bladder (2173 cm² kg⁻¹) exceeded that of the gills (780 cm² kg⁻¹) by a factor of 2.79. Due to the extremely thin air-blood barrier in the swim bladder (harmonic mean 0.22 μm) and the much thicker water-blood barrier of the gills (9.61 μm), the morphometric diffusing capacity for oxygen and carbon dioxide was 88 times greater in the swim bladder than in the gills. These data clearly indicate the importance of the swim bladder, even in juvenile A. gigas that still engage in aquatic respiration. Because of the much greater diffusion constant of CO₂ than O₂ in water, the gills also remain important for CO₂ release. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Rehbinder effect in iron during giga-cycle fatigue loading

NASA Astrophysics Data System (ADS)

Bannikov, M. V.; Naimark, O. B.

2015-10-01

The influence of the adsorptive strength reduction effect (the Rehbinder effect) on the fatigue life of pure iron under the giga-cycle loading regime was investigated. Specimens were loaded by an ultrasonic testing machine with a frequency of 20 kHz in air and in contact with eutectic alloy of gallium with tin and indium. A significant (by several orders of magnitude) worsening of the life-time of iron in contact with a molten metal as compared with tests in air was established. The liquid metal penetrates into the material to a depth of 200 μm to the center of a fatigue crack. The mechanism of the fatigue crack initiation in the giga-cycle regime of loading in contact with a surfactant is differing: the crack is formed on the surface of the specimen rather than within it as is the case for air. Based on the electron and optical microscopy data for the fracture surface, it can be concluded that exactly the change in the crack initiation mechanism reduces the fatigue life of iron in contact with a liquid metal because the initiated crack propagates regardless of the surfactant.

Unusual varieties and duplication of Rig-I like receptors encoded in the marine mollusk, Crassostrea gigas

NASA Astrophysics Data System (ADS)

Tian, Z. H.; Jiao, C. Z.

2017-07-01

RIG-I like receptors (RLRs) play key roles in sensing non-self nucleic acids in cytoplasm and trigger antiviral innate immune response in vertebrates and human body. Here we carried out in silico analysis to identify and investigate the putative RLRs encoded in the genome of marine mollusk, Crassostrea gigas (cgRLRs), an invertebrate species. We found the unusual duplication and varieties on domain architecture of putative cgRLRs encoded in the genome of C. gigas. Three putative cgRLRs (accessions numbers are EKC24603, EKC31344.1 and EKC38304.1 on GenBank), have the similar domain architecture with that of human RIG-I or MDA5, and one protein (EKC34573.1) with that of human LGP2; The fifth putative cgRLRs (EKC38303.1) is somewhat similar with human RIG-I/MDA5 except that it has only one caspase activation and recruitment domain (CARD) in its N-terminal. Other nine proteins were identified to be partialy similar with RLRs while with the incomplete sequences, which maybe reflect the events of partial duplication of cgRLRs genes occurred in the oyster genome.

Sodium influxes in internally perfused squid giant axon during voltage clamp.

PubMed

Atwater, I; Bezanilla, F; Rojas, E

1969-05-01

1. An experimental method for measuring ionic influxes during voltage clamp in the giant axon of Dosidicus is described; the technique combines intracellular perfusion with a method for controlling membrane potential.2. Sodium influx determinations were carried out while applying rectangular pulses of membrane depolarization. The ratio ;measured sodium influx/computed ionic flux during the early current' is 0.92 +/- 0.12.3. Plots of measured sodium influx and computed ionic flux during the early current against membrane potential are very similar. There was evidence that the membrane potential at which the sodium influx vanishes is the potential at which the early current reverses.

Molecular Characterization of Voltage-Gated Sodium Channels and Their Relations with Paralytic Shellfish Toxin Bioaccumulation in the Pacific Oyster Crassostrea gigas

PubMed Central

Boullot, Floriane; Castrec, Justine; Bidault, Adeline; Dantas, Natanael; Payton, Laura; Perrigault, Mickael; Tran, Damien; Amzil, Zouher; Boudry, Pierre; Soudant, Philippe; Hégaret, Hélène; Fabioux, Caroline

2017-01-01

Paralytic shellfish toxins (PST) bind to voltage-gated sodium channels (Nav) and block conduction of action potential in excitable cells. This study aimed to (i) characterize Nav sequences in Crassostrea gigas and (ii) investigate a putative relation between Nav and PST-bioaccumulation in oysters. The phylogenetic analysis highlighted two types of Nav in C. gigas: a Nav1 (CgNav1) and a Nav2 (CgNav2) with sequence properties of sodium-selective and sodium/calcium-selective channels, respectively. Three alternative splice transcripts of CgNav1 named A, B and C, were characterized. The expression of CgNav1, analyzed by in situ hybridization, is specific to nervous cells and to structures corresponding to neuromuscular junctions. Real-time PCR analyses showed a strong expression of CgNav1A in the striated muscle while CgNav1B is mainly expressed in visceral ganglia. CgNav1C expression is ubiquitous. The PST binding site (domain II) of CgNav1 variants possess an amino acid Q that could potentially confer a partial saxitoxin (STX)-resistance to the channel. The CgNav1 genotype or alternative splicing would not be the key point determining PST bioaccumulation level in oysters. PMID:28106838

Anti-Inflammatory Effect of Angelica gigas via Heme Oxygenase (HO)-1 Expression.

PubMed

Cho, Joon Hyeong; Kwon, Jung Eun; Cho, Youngmi; Kim, Inhye; Kang, Se Chan

2015-06-15

Angelica gigas (AG) is effective against various medical conditions such as bacterial infection, inflammation, and cancer. It contains a number of coumarin compounds and the group of interest is the pyranocoumarin, which comprises decursin and decursinol angelate. This group has an effect on controlling inflammation, which is caused by excessive nitric oxide (NO) production. Heme oxygenases (HOs), particularly HO-1, play a role in regulating the production of NO. Thus, this study aimed to investigate the anti-inflammatory effects of AG by measuring HO-1 expression. Treatments with CH2Cl2 layer and Angelica gigas extract (AGE) showed the highest NO inhibition effects. Decursin, decursinol angelate, and nodakenin were isolated from the CH2Cl2 layer of AGE. Decursin also demonstrated the highest anti-oxidative effect among the coumarins. Although decursin had the best NO inhibition and anti-oxidative effects, the effects of AGE treatment far surpassed that of decursin. This is owing to the combination effect of the coumarins present within AGE, which is a solvent extract of AG. The expression of HO-1 is an effective indicator of the anti-inflammatory effects of AG. Based on the results of the coumarin compounds, HO-1 expression was found to be dose dependent and specific to decursin.

Anti-Inflammatory Effect of Angelica gigas via Heme Oxygenase (HO)-1 Expression

PubMed Central

Cho, Joon Hyeong; Kwon, Jung Eun; Cho, Youngmi; Kim, Inhye; Kang, Se Chan

2015-01-01

Angelica gigas (AG) is effective against various medical conditions such as bacterial infection, inflammation, and cancer. It contains a number of coumarin compounds and the group of interest is the pyranocoumarin, which comprises decursin and decursinol angelate. This group has an effect on controlling inflammation, which is caused by excessive nitric oxide (NO) production. Heme oxygenases (HOs), particularly HO-1, play a role in regulating the production of NO. Thus, this study aimed to investigate the anti-inflammatory effects of AG by measuring HO-1 expression. Treatments with CH2Cl2 layer and Angelica gigas extract (AGE) showed the highest NO inhibition effects. Decursin, decursinol angelate, and nodakenin were isolated from the CH2Cl2 layer of AGE. Decursin also demonstrated the highest anti-oxidative effect among the coumarins. Although decursin had the best NO inhibition and anti-oxidative effects, the effects of AGE treatment far surpassed that of decursin. This is owing to the combination effect of the coumarins present within AGE, which is a solvent extract of AG. The expression of HO-1 is an effective indicator of the anti-inflammatory effects of AG. Based on the results of the coumarin compounds, HO-1 expression was found to be dose dependent and specific to decursin. PMID:26083119

Revision of the camel spider genus Eremocosta Roewer and a description of the female Eremocosta gigas Roewer (Arachnida, Solifugae).

PubMed

Cushing, Paula E; Channiago, Felix; Brookhart, Jack O

2018-03-29

A recent phylogenetic analysis demonstrated that the solifuge genus Eremocosta (Eremobatidae), although not monophyletic, formed a strongly supported group, rendered paraphyletic by the exclusion of E. acuitlapanensis, which we herein determine is misplaced in this genus. We revise the taxonomy of the genus Eremocosta. Nine species of the 13 currently placed in the genus are retained, E. bajaensis (Muma 1986), E. calexicensis (Muma 1951), E. formidabilus (Simon 1879), E. gigas Roewer 1934, E. gigasella (Muma 1970), E. spinipalpis (Kraepelin 1899), E. striata (Putnam 1883), and E. titania (Muma 1951). Eremocosta fusca (Muma 1986) and E. montezuma (Roewer 1934) are returned to the genus Eremorhax along with E. arenarum. Eremocosta hystrix and Eremocosta acuitlapanensis (Vázquez Gaviño-Rojas 2000) are transferred to Eremobates. We re-evaluated E. nigrimana (Pocock 1895) and determined that, since the type shows the ventrodistal concavity (VDC) diagnostic for the genus Eremocosta, it should be retained in that genus; however, because the type locality is identified as Afghanistan, far outside the range of any Eremobatidae, its status and placement remain uncertain. Eremocosta robusta (Roewer 1934) was designated nomen dubium by Muma and we maintain this designation. We provide a key to the species of Eremocosta and provide a description of the female of E. gigas.

Genomics Study of the Exposure Effect of Gymnodinium catenatum, a Paralyzing Toxin Producer, on Crassostrea gigas' Defense System and Detoxification Genes

PubMed Central

García-Lagunas, Norma; Romero-Geraldo, Reyna; Hernández-Saavedra, Norma Y.

2013-01-01

Background Crassostrea gigas accumulates paralytic shellfish toxins (PST) associated with red tide species as Gymnodinium catenatum. Previous studies demonstrated bivalves show variable feeding responses to toxic algae at physiological level; recently, only one study has reported biochemical changes in the transcript level of the genes involved in C. gigas stress response. Principal Findings We found that 24 h feeding on toxic dinoflagellate cells (acute exposure) induced a significant decrease in clearance rate and expression level changes of the genes involved in antioxidant defense (copper/zinc superoxide dismutase, Cu/Zn-SOD), cell detoxification (glutathione S-transferase, GST and cytochrome P450, CPY450), intermediate immune response activation (lipopolysaccharide and beta glucan binding protein, LGBP), and stress responses (glutamine synthetase, GS) in Pacific oysters compared to the effects with the non-toxic microalga Isochrysis galbana. A sub-chronic exposure feeding on toxic dinoflagellate cells for seven and fourteen days (30×103 cells mL−1) showed higher gene expression levels. A significant increase was observed in Cu/Zn-SOD, GST, and LGBP at day 7 and a major increase in GS and CPY450 at day 14. We also observed that oysters fed only with G. catenatum (3×103 cells mL−1) produced a significant increase on the transcription level than in a mixed diet (3×103 cells mL−1 of G. catenatum+0.75×106 cells mL−1 I. galbana) in all the analyzed genes. Conclusions Our results provide gene expression data of PST producer dinoflagellate G. catenatum toxic effects on C. gigas, a commercially important bivalve. Over expressed genes indicate the activation of a potent protective mechanism, whose response depends on both cell concentration and exposure time against these toxic microalgae. Given the importance of dinoflagellate blooms in coastal environments, these results provide a more comprehensive overview of how oysters respond to stress generated by toxic dinoflagellate exposure. PMID:24039751

Single oral dose pharmacokinetics of decursin, decursinol angelate, and decursinol in rats.

PubMed

Li, Li; Zhang, Jinhui; Xing, Chengguo; Kim, Sung-Hoon; Lü, Junxuan

2013-03-01

Decursin and decursinol angelate are the major components in the alcoholic extract of the root of Angelica gigas Nakai. Our previous work convincingly demonstrated that both decursin and decursinol angelate were rapidly converted to decursinol in mice after administration by either oral gavage or i. p. injection. In the current study, we compared for the first time the plasma profiles of decursinol, when equal moles of decursin/decursinol angelate or decursinol were given to rats by oral gavage, and investigated the effect of different formulas and other chemicals in Angelica gigas extract on the bioavailability of decursinol. Our results show that gavage of decursinol led to a faster attainment of plasma decursinol peak (Tmax ~ 0.7 h) and much higher peak levels than an equal molar amount administered as decursin/decursinol angelate mixture or as Angelica gigas ethanol extract, resulting in 2-3 fold higher bioavailability as estimated by the area under the curve of the respective regimens (65 012 vs. 27 033 h · ng/mL for decursinol and decursin/decursinol angelate treatment groups, respectively). Compared to a formula based on ethanol-PEG400-Tween80, carboxyl methyl cellulose was a less optimized vehicle. In addition, we detected peak levels of decursin and decursinol angelate in the plasma of rats administered with decursin/decursinol angelate or Angelica gigas extract in the nM range (Tmax ~ 0.5 h) with a newly established sensitive UHPLC-MS/MS method. Furthermore, our data support the liver, instead of intestine, as a major organ site where decursin and decursinol angelate were hydrolyzed to decursinol with a S9 microsomal in vitro metabolism assay. Taken together, our study provided important PK, LC-MS/MS methodology, formulation and metabolism insights in a rodent model for the rational design of in vivo efficacy studies of the corresponding chemicals in the future. Georg Thieme Verlag KG Stuttgart · New York.

CD16-positive circulating monocytes and fibrotic manifestations of systemic sclerosis.

PubMed

Lescoat, Alain; Lecureur, Valérie; Roussel, Mikael; Sunnaram, Béatrice Ly; Ballerie, Alice; Coiffier, Guillaume; Jouneau, Stéphane; Fardel, Olivier; Fest, Thierry; Jégo, Patrick

2017-07-01

The objective of this study is to assess the association of clinical manifestations of systemic sclerosis (SSc) with the absolute count of circulating blood monocyte subpopulations according to their membrane expression of CD16. Forty-eight consecutive patients fulfilling the 2013 ACR/EULAR classification criteria for SSc were included in this cross-sectional study. CD16+ monocyte absolute count was defined by flow cytometry and confronted to the clinical characteristics of SSc patients. Twenty-three healthy donors (HD) were randomly selected for comparison. SSc patients had an increased number of total circulating blood monocytes compared to HD (p < 0.001). The CD16- subpopulation absolute count was increased in SSc patients compared to HD (p < 0.001) but was similar in limited SSc (lSSc) and diffuse SSc (dSSc). On the contrary, the CD16+ population absolute count was increased in dSSc compared to both HD and lSSc patients (dSSc 0.071 Giga/L (±0.034) vs HD 0.039 Giga/L (±0.030), p < 0.01, and dSSc 0.071 Giga/L (±0.034) vs lSSc 0.048 Giga/L (±0.024), p < 0.05). The CD16+ monocyte subpopulation absolute count was significantly correlated with the severity of skin fibrosis evaluated by the modified Rodnan skin score (p < 0.001). The CD16+ monocyte subpopulation was also associated with pulmonary fibrosis (p < 0.05), with the severity of the restrictive ventilatory defect evaluated by total lung capacity (p < 0.05) and with the pulmonary function impairment reflected by diffusing capacity of the lungs for carbon monoxyde measures (p < 0.01). These results suggest that CD16+ monocytes are associated with the main fibrotic manifestations of SSc and their role in the pathogenesis of fibrosis in this autoimmune disorder should therefore be further considered.

Sodium influxes in internally perfused squid giant axon during voltage clamp

PubMed Central

Atwater, I.; Bezanilla, F.; Rojas, E.

1969-01-01

1. An experimental method for measuring ionic influxes during voltage clamp in the giant axon of Dosidicus is described; the technique combines intracellular perfusion with a method for controlling membrane potential. 2. Sodium influx determinations were carried out while applying rectangular pulses of membrane depolarization. The ratio `measured sodium influx/computed ionic flux during the early current' is 0·92 ± 0·12. 3. Plots of measured sodium influx and computed ionic flux during the early current against membrane potential are very similar. There was evidence that the membrane potential at which the sodium influx vanishes is the potential at which the early current reverses. PMID:5767887

Observation of pulsed gamma-rays above 25 GeV from the Crab pulsar with MAGIC.

PubMed

Aliu, E; Anderhub, H; Antonelli, L A; Antoranz, P; Backes, M; Baixeras, C; Barrio, J A; Bartko, H; Bastieri, D; Becker, J K; Bednarek, W; Berger, K; Bernardini, E; Bigongiari, C; Biland, A; Bock, R K; Bonnoli, G; Bordas, P; Bosch-Ramon, V; Bretz, T; Britvitch, I; Camara, M; Carmona, E; Chilingarian, A; Commichau, S; Contreras, J L; Cortina, J; Costado, M T; Covino, S; Curtef, V; Dazzi, F; De Angelis, A; De Cea Del Pozo, E; de Los Reyes, R; De Lotto, B; De Maria, M; De Sabata, F; Delgado Mendez, C; Dominguez, A; Dorner, D; Doro, M; Elsässer, D; Errando, M; Fagiolini, M; Ferenc, D; Fernandez, E; Firpo, R; Fonseca, M V; Font, L; Galante, N; Garcia Lopez, R J; Garczarczyk, M; Gaug, M; Goebel, F; Hadasch, D; Hayashida, M; Herrero, A; Höhne, D; Hose, J; Hsu, C C; Huber, S; Jogler, T; Kranich, D; La Barbera, A; Laille, A; Leonardo, E; Lindfors, E; Lombardi, S; Longo, F; Lopez, M; Lorenz, E; Majumdar, P; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Mariotti, M; Martinez, M; Mazin, D; Meucci, M; Meyer, M; Miranda, J M; Mirzoyan, R; Moles, M; Moralejo, A; Nieto, D; Nilsson, K; Ninkovic, J; Otte, N; Oya, I; Paoletti, R; Paredes, J M; Pasanen, M; Pascoli, D; Pauss, F; Pegna, R G; Perez-Torres, M A; Persic, M; Peruzzo, L; Piccioli, A; Prada, F; Prandini, E; Puchades, N; Raymers, A; Rhode, W; Ribó, M; Rico, J; Rissi, M; Robert, A; Rügamer, S; Saggion, A; Saito, T Y; Salvati, M; Sanchez-Conde, M; Sartori, P; Satalecka, K; Scalzotto, V; Scapin, V; Schweizer, T; Shayduk, M; Shinozaki, K; Shore, S N; Sidro, N; Sierpowska-Bartosik, A; Sillanpää, A; Sobczynska, D; Spanier, F; Stamerra, A; Stark, L S; Takalo, L; Tavecchio, F; Temnikov, P; Tescaro, D; Teshima, M; Tluczykont, M; Torres, D F; Turini, N; Vankov, H; Venturini, A; Vitale, V; Wagner, R M; Wittek, W; Zabalza, V; Zandanel, F; Zanin, R; Zapatero, J; de Jager, O C; de Ona Wilhelmi, E

2008-11-21

One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring the high-end region of a pulsar's spectrum would shed light on this question. By developing a new electronic trigger, we lowered the threshold of the Major Atmospheric gamma-ray Imaging Cherenkov (MAGIC) telescope to 25 giga-electron volts. In this configuration, we detected pulsed gamma-rays from the Crab pulsar that were greater than 25 giga-electron volts, revealing a relatively high cutoff energy in the phase-averaged spectrum. This indicates that the emission occurs far out in the magnetosphere, hence excluding the polar-cap scenario as a possible explanation of our measurement. The high cutoff energy also challenges the slot-gap scenario.

A 10 Gb/s laser driver in 130 nm CMOS technology for high energy physics applications

DOE PAGES

Zhang, T.; Tavernier, F.; Moreira, P.; ...

2015-02-19

The GigaBit Laser Driver (GBLD) is a key on-detector component of the GigaBit Transceiver (GBT) system at the transmitter side. We have developed a 10 Gb/s GBLD (GBLD10) in a 130 nm CMOS technology, as part of the design efforts towards the upgrade of the electrical components of the LHC experiments. The GBLD10 is based on the distributed-amplifier (DA) architecture and achieves data rates up to 10 Gb/s. It is capable of driving VCSELs with modulation currents up to 12 mA. Furthermore, a pre-emphasis function has been included in the proposed laser driver in order to compensate for the capacitivemore » load and channel losses.« less

Realized detection and capture probabilities for giant gartersnakes (Thamnophis gigas) using modified floating aquatic funnel traps

USGS Publications Warehouse

Halstead, Brian J.; Skalos, Shannon M.; Casazza, Michael L.; Wylie, Glenn D.

2015-01-01

Detection and capture probabilities for giant gartersnakes (Thamnophis gigas) are very low, and successfully evaluating the effects of variables or experimental treatments on giant gartersnake populations will require greater detection and capture probabilities than those that had been achieved with standard trap designs. Previous research identified important trap modifications that can increase the probability of snakes entering traps and help prevent the escape of captured snakes. The purpose of this study was to quantify detection and capture probabilities obtained using the most successful modification to commercially available traps to date (2015), and examine the ability of realized detection and capture probabilities to achieve benchmark levels of precision in occupancy and capture-mark-recapture studies.

Large and linked in scientific publishing

PubMed Central

2012-01-01

We are delighted to announce the launch of GigaScience, an online open-access journal that focuses on research using or producing large datasets in all areas of biological and biomedical sciences. GigaScience is a new type of journal that provides standard scientific publishing linked directly to a database that hosts all the relevant data. The primary goals for the journal, detailed in this editorial, are to promote more rapid data release, broader use and reuse of data, improved reproducibility of results, and direct, easy access between analyses and their data. Direct and permanent connections of scientific analyses and their data (achieved by assigning all hosted data a citable DOI) will enable better analysis and deeper interpretation of the data in the future. PMID:23587310

Large and linked in scientific publishing.

PubMed

Goodman, Laurie; Edmunds, Scott C; Basford, Alexandra T

2012-07-12

We are delighted to announce the launch of GigaScience, an online open-access journal that focuses on research using or producing large datasets in all areas of biological and biomedical sciences. GigaScience is a new type of journal that provides standard scientific publishing linked directly to a database that hosts all the relevant data. The primary goals for the journal, detailed in this editorial, are to promote more rapid data release, broader use and reuse of data, improved reproducibility of results, and direct, easy access between analyses and their data. Direct and permanent connections of scientific analyses and their data (achieved by assigning all hosted data a citable DOI) will enable better analysis and deeper interpretation of the data in the future.

High pressure treatment changes spoilage characteristics and shelf life of Pacific oysters ( Crassostrea gigas) during refrigerated storage

NASA Astrophysics Data System (ADS)

Cao, Rong; Zhao, Ling; Liu, Qi

2017-04-01

The effects of high pressure (HP) treatment on spoilage characteristic and shelf life extension of Pacific oysters ( Crassostrea gigas) during refrigerated storage were studied. Results showed that HP treatment of 275 MPa for 3 min or 300 MPa for 2 min could achieve 100% full release of oyster adductor muscle, pressures higher than 350 MPa caused excessive release as the shells of oysters were broken, thus use of higher pressures should be cautious in oyster processing industry because of its adverse impact on the appearance of shells. HP treatment (300 MPa, 2 min) was proper for the shucking of Pacific oyster ( Crassostrea gigas) in China. This treatment caused no organoleptic disadvantage. Moreover, HP treatment resulted in obvious differences in biochemical spoilage indicators (pH, TVB-N and TBARS) changes and volatile compounds profile determined by electronic nose during storage. HP treatment (300 MPa, 2 min) also led to a reduction of aerobic bacterial count (APC) by 1.27 log cycles. Furthermore, the APC values of oysters treated by HP were always lower than those of the control samples during storage. Based on the organoleptic, biochemical and microbiological indicators, shelf life of 6-8 d for control and 12 d for HP-treated oysters could be expected. HP treatment showed great potential in oyster processing and preservation.

The pea GIGAS gene is a FLOWERING LOCUS T homolog necessary for graft-transmissible specification of flowering but not for responsiveness to photoperiod.

PubMed

Hecht, Valérie; Laurie, Rebecca E; Vander Schoor, Jacqueline K; Ridge, Stephen; Knowles, Claire L; Liew, Lim Chee; Sussmilch, Frances C; Murfet, Ian C; Macknight, Richard C; Weller, James L

2011-01-01

Garden pea (Pisum sativum) was prominent in early studies investigating the genetic control of flowering and the role of mobile flowering signals. In view of recent evidence that genes in the FLOWERING LOCUS T (FT) family play an important role in generating mobile flowering signals, we isolated the FT gene family in pea and examined the regulation and function of its members. Comparison with Medicago truncatula and soybean (Glycine max) provides evidence of three ancient subclades (FTa, FTb, and FTc) likely to be common to most crop and model legumes. Pea FT genes show distinctly different expression patterns with respect to developmental timing, tissue specificity, and response to photoperiod and differ in their activity in transgenic Arabidopsis thaliana, suggesting they may have different functions. We show that the pea FTa1 gene corresponds to the GIGAS locus, which is essential for flowering under long-day conditions and promotes flowering under short-day conditions but is not required for photoperiod responsiveness. Grafting, expression, and double mutant analyses show that GIGAS/FTa1 regulates a mobile flowering stimulus but also provide clear evidence for a second mobile flowering stimulus that is correlated with expression of FTb2 in leaf tissue. These results suggest that induction of flowering by photoperiod in pea results from interactions among several members of a diversified FT family.

Detection of early effects of a single herbicide (diuron) and a mix of herbicides and pharmaceuticals (diuron, isoproturon, ibuprofen) on immunological parameters of Pacific oyster (Crassostrea gigas) spat.

PubMed

Luna-Acosta, A; Renault, T; Thomas-Guyon, H; Faury, N; Saulnier, D; Budzinski, H; Le Menach, K; Pardon, P; Fruitier-Arnaudin, I; Bustamante, P

2012-06-01

In the context of massive summer mortality events of the Pacific oyster Crassostrea gigas, the aim of this study was to investigate the early effects on genes, enzymes and haemocyte parameters implicated in immune defence mechanisms in C. gigas oysters exposed to a potentially hostile environment, i.e. to an herbicide alone or within a mixture. Following 2 h of exposure to the herbicide diuron at 1 μg L(-1), the repression of different genes implicated in immune defence mechanisms in the haemocytes and the inhibition of enzyme activities, such as laccase-type phenoloxidase (PO) in the plasma, were observed. The inhibition of superoxide dismutase (SOD) activity in the plasma was also observed after 6 and 24 h of exposure. In the mixture with the herbicides diuron and isoproturon, and the pharmaceutical ibuprofen, catecholase-type PO activity in the plasma and the percentage of phagocytosis in the haemocytes were reduced after 6 h of exposure. Our results showed that early effects on molecular, biochemical and cellular parameters can be detected in the presence of diuron alone or within a mixture, giving an insight of its potential effect in situations that can be found in natural environments, i.e. relatively high concentrations for short periods of time. Copyright © 2012 Elsevier Ltd. All rights reserved.

Development and validation of an ultra-performance convergence chromatography method for the quality control of Angelica gigas Nakai.

PubMed

Kim, Hyo Seon; Chun, Jin Mi; Kwon, Bo-In; Lee, A-Reum; Kim, Ho Kyoung; Lee, A Yeong

2016-10-01

Ultra-performance convergence chromatography, which integrates the advantages of supercritical fluid chromatography and ultra high performance liquid chromatography technologies, is an environmentally friendly analytical method that uses dramatically reduced amounts of organic solvents. An ultra-performance convergence chromatography method was developed and validated for the quantification of decursinol angelate and decursin in Angelica gigas using a CSH Fluoro-Phenyl column (2.1 mm × 150 mm, 1.7 μm) with a run time of 4 min. The method had an improved resolution and a shorter analysis time in comparison to the conventional high-performance liquid chromatography method. This method was validated in terms of linearity, precision, and accuracy. The limits of detection were 0.005 and 0.004 μg/mL for decursinol angelate and decursin, respectively, while the limits of quantitation were 0.014 and 0.012 μg/mL, respectively. The two components showed good regression (correlation coefficient (r 2 ) > 0.999), excellent precision (RSD < 2.28%), and acceptable recoveries (99.75-102.62%). The proposed method can be used to efficiently separate, characterize, and quantify decursinol angelate and decursin in Angelica gigas and its related medicinal materials or preparations, with the advantages of a shorter analysis time, greater sensitivity, and better environmental compatibility. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metabolic Energy Demand Is Not Increased during Initial Shell Formation of Bivalves Exposed to Aragonite Undersaturation

NASA Astrophysics Data System (ADS)

Pan, F.; Frieder, C.; Applebaum, S.; Manahan, D. T.

2016-02-01

The Pacific oyster, Crassostrea gigas, is a major commercial species in global aquaculture. Ocean acidification is having a negative effect on larval production of this species, so the mechanisms of this impact are of considerable interest. Formation of new shell in C. gigas during the first 2-days post-fertilization results in a rapid six-fold increase in total mass. This period of early development has high sensitivity to changes in carbonate chemistry, in particular aragonite saturation state (Ω). An elevated energy cost for calcification at low Ω is often invoked as a mechanism. In this study, we characterized the developmental progression of first shell formation, total metabolic expenditure, and underlying biochemical processes of energy allocation during early development of C. gigas, under control (Ω >> 1) and undersaturated conditions (Ω < 1). While undersaturated conditions delayed the onset of calcification and resulted in decreased shell mass, there was no change in total metabolic energy demand. Furthermore, partitioning of total metabolic energy showed no major re-allocation of ATP to protein synthesis or ion pump activity (Na+, K+-ATPase) between the two treatments. We conclude that early development to the shelled-veliger larval stage does not require more energy at undersaturation. This finding helps constrain potential mechanisms of larval sensitivity to ocean acidification and narrows the focus for possible mitigation strategies for oyster aquaculture production.

Paralytic Toxins Accumulation and Tissue Expression of α-Amylase and Lipase Genes in the Pacific Oyster Crassostrea gigas Fed with the Neurotoxic Dinoflagellate Alexandrium catenella

PubMed Central

Rolland, Jean-Luc; Pelletier, Kevin; Masseret, Estelle; Rieuvilleneuve, Fabien; Savar, Veronique; Santini, Adrien; Amzil, Zouher; Laabir, Mohamed

2012-01-01

The pacific oyster Crassostrea gigas was experimentally exposed to the neurotoxic Alexandrium catenella and a non-producer of PSTs, Alexandrium tamarense (control algae), at concentrations corresponding to those observed during the blooming period. At fixed time intervals, from 0 to 48 h, we determined the clearance rate, the total filtered cells, the composition of the fecal ribbons, the profile of the PSP toxins and the variation of the expression of two α-amylase and triacylglecerol lipase precursor (TLP) genes through semi-quantitative RT-PCR. The results showed a significant decrease of the clearance rate of C. gigas fed with both Alexandrium species. However, from 29 to 48 h, the clearance rate and cell filtration activity increased only in oysters fed with A. tamarense. The toxin concentrations in the digestive gland rose above the sanitary threshold in less than 48 h of exposure and GTX6, a compound absent in A. catenella cells, accumulated. The α-amylase B gene expression level increased significantly in the time interval from 6 to 48 h in the digestive gland of oysters fed with A. tamarense, whereas the TLP gene transcript was significantly up-regulated in the digestive gland of oysters fed with the neurotoxic A. catenella. All together, these results suggest that the digestion capacity could be affected by PSP toxins. PMID:23203275

Cellular and Transcriptional Responses of Crassostrea gigas Hemocytes Exposed in Vitro to Brevetoxin (PbTx-2)

PubMed Central

Mello, Danielle F.; de Oliveira, Eliza S.; Vieira, Renato C.; Simoes, Erik; Trevisan, Rafael; Dafre, Alcir Luiz; Barracco, Margherita Anna

2012-01-01

Hemocytes mediate a series of immune reactions essential for bivalve survival in the environment, however, the impact of harmful algal species and their associated phycotoxins upon bivalve immune system is under debate. To better understand the possible toxic effects of these toxins, Crassostrea gigas hemocytes were exposed to brevetoxin (PbTx-2). Hemocyte viability, monitored through the neutral red retention and MTT reduction assays, and apoptosis (Hoechst staining) remained unchanged during 12 h of exposure to PbTx-2 in concentrations up to 1000 µg/L. Despite cell viability and apoptosis remained stable, hemocytes incubated for 4 h with 1000 µg/L of PbTx-2 revealed higher expression levels of Hsp70 (p < 0.01) and CYP356A1 (p < 0.05) transcripts and a tendency to increase FABP expression, as evaluated by Real-Time quantitative PCR. The expression of other studied genes (BPI, IL-17, GSTO, EcSOD, Prx6, SOD and GPx) remained unchanged. The results suggest that the absence of cytotoxic effects of PbTx-2 in Crassostrea gigas hemocytes, even at high concentrations, allow early defense responses to be produced by activating protective mechanisms associated to detoxification (CYP356A1 and possibly FABP) and stress (Hsp70), but not to immune or to antioxidant (BPI, IL-17, EcSOD, Prx6, GPx and SOD) related genes. PMID:22611355

[Phylogenetic analysis of tyrosinase gene family in the Pacific oyster (Crassostrea gigas Thunberg)].

PubMed

Yu, Xue; Yu, Hong; Kong, Lingfeng; Li, Qi

2014-02-01

The deduced amino acid sequence characteristics, classification and phylogeny of tyrosinase gene family in the Pacific oyster (Crassostrea gigas Thunberg) were analyzed using bioinformatics methods. The results showed that gene duplication was the major cause of tyrosinase gene expansion in the Pacific oyster. The tyrosinase gene family in the Pacific oyster can be further classified into three types: secreted form (Type A), cytosolic form (Type B) and membrane-bound form (Type C). Based on the topology of the phylogenetic tree of the Pacific oyster tyrosinases, among Type A isoforms, tyr18 seemed divergent from other Type A tyrosinases early, while tyr2 and tyr9 appeared divergent early in Type B. In Type C tyrosinses, tyr8 was divergent early. The cluster of the Pacific oyster tyrosinasesis determined by their classifications and positions in the scaffolds. Further analysis suggested that Type A tyrosinases of C. gigas clustered with those from cephalopods and then with nematodes and cnidarians. Type B tyrosinases were generally clustered with the same type of tyrosinases from molluscas and nematodes, and then with those from platyhelminths, cnidarians and chordates. Type A tyrosinases in the Pacific oyster and the Pearl oyster expanded independently and were divergent from membrane-bound form of tyrosinases in chordata, platyhelminthes and annelida. These observations suggested that Type C tyrosinases in the bivalve had a distinct evolution direction.

Implications for osmorespiratory compromise by anatomical remodeling in the gills of Arapaima gigas.

PubMed

Ramos, Cleverson Agner; Fernandes, Marisa Narciso; da Costa, Oscar Tadeu Ferreira; Duncan, Wallice Paxiuba

2013-10-01

The gill structure of the Amazonian fish Arapaima gigas, an obligatory air breather, was investigated during its transition from water breathing to the obligatory air breathing modes of respiration. The gill structure of A. gigas larvae is similar to that of most teleost fish; however, the morphology of the gills changes as the fish grow. The main morphological changes in the gill structure of a growing fish include the following: (1) intense cell proliferation in the filaments and lamellae, resulting in increasing epithelial thickness and decreasing interlamellar distance; (2) pillar cell system atrophy, which reduces the blood circulation through the lamellae; (3) the generation of long cytoplasmic processes from the epithelial cells into the intercellular space, resulting in continuous and sinuous paracellular channels between the epithelial cells of the filament and lamella that may be involved in gas, ion, and nutrient transport to epithelial cells; and (4) intense mitochondria-rich cell (MRC) proliferation in the lamellar epithelium. All of these morphological changes in the gills contribute to a low increase of the respiratory surface area for gas exchange and an increase in the water-blood diffusion distance increasing their dependence on air-breathing as fish developed. The increased proliferation of MRCs may contribute to increased ion uptake, which favors the regulation of ion content and pH equilibrium. Copyright © 2013 Wiley Periodicals, Inc.

Giga-pixel lensfree holographic microscopy and tomography using color image sensors.

PubMed

Isikman, Serhan O; Greenbaum, Alon; Luo, Wei; Coskun, Ahmet F; Ozcan, Aydogan

2012-01-01

We report Giga-pixel lensfree holographic microscopy and tomography using color sensor-arrays such as CMOS imagers that exhibit Bayer color filter patterns. Without physically removing these color filters coated on the sensor chip, we synthesize pixel super-resolved lensfree holograms, which are then reconstructed to achieve ~350 nm lateral resolution, corresponding to a numerical aperture of ~0.8, across a field-of-view of ~20.5 mm(2). This constitutes a digital image with ~0.7 Billion effective pixels in both amplitude and phase channels (i.e., ~1.4 Giga-pixels total). Furthermore, by changing the illumination angle (e.g., ± 50°) and scanning a partially-coherent light source across two orthogonal axes, super-resolved images of the same specimen from different viewing angles are created, which are then digitally combined to synthesize tomographic images of the object. Using this dual-axis lensfree tomographic imager running on a color sensor-chip, we achieve a 3D spatial resolution of ~0.35 µm × 0.35 µm × ~2 µm, in x, y and z, respectively, creating an effective voxel size of ~0.03 µm(3) across a sample volume of ~5 mm(3), which is equivalent to >150 Billion voxels. We demonstrate the proof-of-concept of this lensfree optical tomographic microscopy platform on a color CMOS image sensor by creating tomograms of micro-particles as well as a wild-type C. elegans nematode.

Trophic modeling of the Northern Humboldt Current Ecosystem, Part I: Comparing trophic linkages under La Niña and El Niño conditions

NASA Astrophysics Data System (ADS)

Tam, Jorge; Taylor, Marc H.; Blaskovic, Verónica; Espinoza, Pepe; Michael Ballón, R.; Díaz, Erich; Wosnitza-Mendo, Claudia; Argüelles, Juan; Purca, Sara; Ayón, Patricia; Quipuzcoa, Luis; Gutiérrez, Dimitri; Goya, Elisa; Ochoa, Noemí; Wolff, Matthias

2008-10-01

The El Niño of 1997-98 was one of the strongest warming events of the past century; among many other effects, it impacted phytoplankton along the Peruvian coast by changing species composition and reducing biomass. While responses of the main fish resources to this natural perturbation are relatively well known, understanding the ecosystem response as a whole requires an ecotrophic multispecies approach. In this work, we construct trophic models of the Northern Humboldt Current Ecosystem (NHCE) and compare the La Niña (LN) years in 1995-96 with the El Niño (EN) years in 1997-98. The model area extends from 4°S-16°S and to 60 nm from the coast. The model consists of 32 functional groups of organisms and differs from previous trophic models of the Peruvian system through: (i) division of plankton into size classes to account for EN-associated changes and feeding preferences of small pelagic fish, (ii) increased division of demersal groups and separation of life history stages of hake, (iii) inclusion of mesopelagic fish, and (iv) incorporation of the jumbo squid ( Dosidicus gigas), which became abundant following EN. Results show that EN reduced the size and organization of energy flows of the NHCE, but the overall functioning (proportion of energy flows used for respiration, consumption by predators, detritus and export) of the ecosystem was maintained. The reduction of diatom biomass during EN forced omnivorous planktivorous fish to switch to a more zooplankton-dominated diet, raising their trophic level. Consequently, in the EN model the trophic level increased for several predatory groups (mackerel, other large pelagics, sea birds, pinnipeds) and for fishery catch. A high modeled biomass of macrozooplankton was needed to balance the consumption by planktivores, especially during EN condition when observed diatoms biomass diminished dramatically. Despite overall lower planktivorous fish catches, the higher primary production required-to-catch ratio implied a stronger ecological impact of the fishery and stresses the need for precautionary management of fisheries during and after EN. During EN energetic indicators such as the lower primary production/total biomass ratio suggest a more energetically efficient ecosystem, while reduced network indicators such as the cycling index and relative ascendency indicate of a less organized state of the ecosystem. Compared to previous trophic models of the NHCE we observed: (i) a shrinking of ecosystem size in term of energy flows, (ii) slight changes in overall functioning (proportion of energy flows used for respiration, consumption by predators and detritus), and (iii) the use of alternate pathways leading to a higher ecological impact of the fishery for planktivorous fish.

Abdominal contents from two large early cretaceous compsognathids (Dinosauria: Theropoda) demonstrate feeding on confuciusornithids and dromaeosaurids.

PubMed

Xing, Lida; Bell, Phil R; Persons, W Scott; Ji, Shuan; Miyashita, Tetsuto; Burns, Michael E; Ji, Qiang; Currie, Philip J

2012-01-01

Two skeletons of the large compsognathid Sinocalliopteryx gigas include intact abdominal contents. Both specimens come from the Jianshangou Beds of the lower Yixian Formation (Neocomian), Liaoning, China. The holotype of S. gigas preserves a partial dromaeosaurid leg in the abdominal cavity, here attributed to Sinornithosaurus. A second, newly-discovered specimen preserves the remains of at least two individuals of the primitive avialan, Confuciusornis sanctus, in addition to acid-etched bones from a possible ornithischian. Although it cannot be stated whether such prey items were scavenged or actively hunted, the presence of two Confuciusornis in a grossly similar state of digestion suggests they were consumed in rapid succession. Given the lack of clear arboreal adaptations in Sinocalliopteryx, we suggest it may have been an adept stealth hunter.

Decursin: a cytotoxic agent and protein kinase C activator from the root of Angelica gigas.

PubMed

Ahn, K S; Sim, W S; Kim, I H

1996-02-01

A cytotoxic compound was purified from the root of Angelica gigas Nakai by silica gel chromatography and preparative HPLC. As a result of the structure analysis by mass, IR, 1H-NMR, and 13C-NMR spectrometry, the effective compound was identified as decursin, a pyranocoumarin characterized originally from Angelica decursiva Fr. et Sav. In vitro cytotoxicity testing showed that decursin displayed toxic activity against various human cancer cell lines, for which the ED50 of decursin was about 5-16 micrograms/ml. On the other hand, decursin displayed relatively low cytotoxicity against normal fibroblasts. Decursin also activated protein kinase C (PKC) in vitro, which indicates that the cytotoxic activity of decursin may be related to the protein kinase C activation.

Gravity and light effects on the circadian clock of a desert beetle, Trigonoscelis gigas

NASA Technical Reports Server (NTRS)

Hoban-Higgins, T. M.; Alpatov, A. M.; Wassmer, G. T.; Rietveld, W. J.; Fuller, C. A.

2003-01-01

Circadian function is affected by exposure to altered ambient force environments. Under non-earth gravitational fields, both basic features of circadian rhythms and the expression of the clock responsible for these rhythms are altered. We examined the activity rhythm of the tenebrionid beetle, Trigonoscelis gigas, in conditions of microgravity (microG; spaceflight), earth's gravity (1 G) and 2 G (centrifugation). Data were recorded under a light-dark cycle (LD), constant light (LL), and constant darkness (DD). Free-running period (tau) was significantly affected by both the gravitational field and ambient light intensity. In DD, tau was longer under 2 G than under either 1 G or microG. In addition, tauLL was significantly different from tauDD under microG and 1 G, but not under 2 G.

Adult Pacific Oyster (Crassostrea gigas) May Have Light Sensitivity

PubMed Central

Yang, Yanjian; Li, Zhuang; Guo, Ting; Li, Yongchuan; Wang, Xiaotong

2015-01-01

Light-sensitivity is an important aspect of mollusk survival as it plays a vital role in reproduction and predator avoidance. In the Pacific oyster Crassostrea gigas light sensitivity has been demonstrated in the larval stage but has not yet been conclusively demonstrated in adult oysters. In this paper we describe an experiment which was undertaken to determine if adult Pacific oysters were sensitive to light. One LED flashlight was used to shine light onto adult oysters while they were filtering seawater through their shell openings. We found that the degree of opening increased gradually during the light period but rapidly decreased when the flashlight was turned off in the treated group but not in the control group. These results suggest that adult Pacific oyster may be sensitive to light. PMID:26474058

Spatial patterns in the condition index of the wild Pacific oyster Crassostrea gigas in a macrotidal coastal ecosystem: Influence of tidal processes and beyond

NASA Astrophysics Data System (ADS)

Gasmi, Sonia; Bernard, Ismaël; Pouvreau, Stéphane; Maurer, Danièle; Schaal, Gauthier; Ganthy, Florian; Cominassi, Louise; Allain, Gwenhael; Sautour, Benoit; David, Valérie

2017-01-01

In macrotidal coastal ecosystems, spatial heterogeneity of the water column properties is induced by both oceanic and continental influences. Hydrodynamic processes generate a land-sea gradient of environmental conditions, affecting the biological performances of sedentary organisms. The aim of the present study is to establish an extensive spatial assessment in the reproductive investment of the wild Pacific oyster Crassostrea gigas in Arcachon Bay. This is done by looking for a relationship between the Lawrence and Scott condition index (LSCI) and two tidal processes: the immersion level (IL) and the local oceanic flushing time (LoFt). The LSCI of C. gigas was assessed, just before gamete release, at 68 sampling stations in Arcachon Bay. Oyster performance was overall low and spatially variable. Significant differences in the LSCI were detected between the outer and inner bay. Oyster reefs located toward the mouth of the bay exhibited high LSCI (between 9 and 11), while oyster reefs located in inner bay, especially in south-eastern part around the Eyre River, had low LSCI (below 6). Linear modelling allowed to highlight significant effects of both tidal processes IL and LoFt on the obtained LSCI gradient. IL, LoFt explained 33% of the spatial variability observed on LSCI (IL = 3%; LoFt = 17%; LoFt + IL: 13%), 6% were attributed to the intra-station variation (ISv). Thus, high IL and rapid LoFt favor a better development of somatic-gonadal volume, probably because of longer feeding time and higher supply of food from the ocean by tide flows. Disentangling the effects of IL and LoFt on LSCI allowed to describe the spatial pattern in 61% of variability not explained by both tidal factors. A residual gradient directed southeast-northwest highlighted that others factors, independent from IL and LoFt seems to hamper inner bay oyster reproductive performance. Consequently, investigating on the ecological functioning (Eyre influences), trophic potential and anthropogenic pressures of this zone seem crucial on the understanding of C. gigas reproductive pattern in Arcachon Bay.

Identification of Thyroid Hormones and Functional Characterization of Thyroid Hormone Receptor in the Pacific Oyster Crassostrea gigas Provide Insight into Evolution of the Thyroid Hormone System

PubMed Central

Huang, Wen; Xu, Fei; Qu, Tao; Zhang, Rui; Li, Li; Que, Huayong; Zhang, Guofan

2015-01-01

Thyroid hormones (THs) play important roles in development, metamorphosis, and metabolism in vertebrates. During the past century, TH functions were regarded as a synapomorphy of vertebrates. More recently, accumulating evidence has gradually convinced us that TH functions also occur in invertebrate chordates. To date, however, TH-related studies in non-chordate invertebrates have been limited. In this study, THs were qualitatively detected by two reliable methods (HPLC and LC/MS) in a well-studied molluscan species, the Pacific oyster Crassostrea gigas. Quantitative measurement of THs during the development of C. gigas showed high TH contents during embryogenesis and that oyster embryos may synthesize THs endogenously. As a first step in elucidating the TH signaling cascade, an ortholog of vertebrate TH receptor (TR), the most critical gene mediating TH effects, was cloned in C. gigas. The sequence of CgTR has conserved DNA-binding and ligand-binding domains that normally characterize these receptors. Experimental results demonstrated that CgTR can repress gene expression through binding to promoters of target genes and can interact with oyster retinoid X receptor. Moreover, CgTR mRNA expression was activated by T4 and the transcriptional activity of CgTR promoter was repressed by unliganded CgTR protein. An atypical thyroid hormone response element (CgDR5) was found in the promoter of CgTR, which was verified by electrophoretic mobility shift assay (EMSA). These results indicated that some of the CgTR function is conserved. However, the EMSA assay showed that DNA binding specificity of CgTR was different from that of the vertebrate TR and experiments with two dual-luciferase reporter systems indicated that l-thyroxine, 3,3′,5-triiodothyronine, and triiodothyroacetic acid failed to activate the transcriptional activity of CgTR. This is the first study to functionally characterize TR in mollusks. The presence of THs and the functions of CgTR in mollusks contribute to better understanding of the evolution of the TH system. PMID:26710071

CIDR

Science.gov Websites

description of GigaMUGA can be found at: The Mouse Universal Genotyping Array: from substrains to subspecies Services page for a full description of what is included for all study types See our Sample Requirements

Temporal and maternal effects on reproductive ecology of the giant gartersnake (Thamnophis gigas)

USGS Publications Warehouse

Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.; Coates, Peter S.

2009-01-01

We used mixed-effects models to examine relationships of reproductive characteristics of the giant gartersnake (Thamnophis gigas) to improve population modeling and conservation planning for this species. Neonates from larger litters had lower mass, and mass of neonates also was affected by random variation among mothers. Length of mother did not affect relative mass of litters; however, our data suggest that longer mothers expended less reproductive effort per offspring than shorter mothers. We detected random variation in length of neonates among mothers, but these lengths were not related to length of mother or size of litter. Mean size of litter varied among years, but little evidence existed for a relationship between size of litter or mass of litter and length of mother. Sex ratios of neonates did not differ from 1:1.

Impact and fracture analysis of fish scales from Arapaima gigas.

PubMed

Torres, F G; Malásquez, M; Troncoso, O P

2015-06-01

Fish scales from the Amazonian fish Arapaima gigas have been characterised to study their impact and fracture behaviour at three different environmental conditions. Scales were cut in two different directions to analyse the influence of the orientation of collagen layers. The energy absorbed during impact tests was measured for each sample and SEM images were taken after each test in order to analyse the failure mechanisms. The results showed that scales tested at cryogenic temperatures display fragile behaviour, while scales tested at room temperature did not fracture. Different failure mechanisms have been identified, analysed and compared with the failure modes that occur in bone. The impact energy obtained for fish scales was two to three times higher than the values reported for bone in the literature. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of drying procedures on the physicochemical properties and antioxidant activities of polysaccharides from Crassostrea gigas

PubMed Central

Zheng, Yaxu; Qu, Min; Jin, Qiao; Tong, Changqing

2017-01-01

Crassostrea gigas polysaccharides (CGP) were obtained by different drying methods: freeze-drying (FD), spray-drying (SD) or rotary evaporation-drying (RED). The physicochemical properties of CGP were evaluated on the basis of polysaccharide content, protein content, color characteristics, FT-IR spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Antioxidant activities were researched three different free radicals, including DPPH free radicals, ABTS free radicals and reducing power. The results demonstrated that FDCGP, SDCGP and REDCGP have different physicochemical properties and antioxidant activities. Contrasted with FDCGP and REDCGP, SDCGP exhibited stronger antioxidant abilities. Therefore, considering the polysaccharides appearances and antioxidant activities, the spray drying method is a decent selection for the preparation of such polysaccharides, and it should be selected for application in the food industry. PMID:29176846

Anticholinesterase activity of endemic plant extracts from Soqotra.

PubMed

Bakthira, Hussein; Awadh Ali, Nasser A; Arnold, Norbert; Teichert, Axel; Wessjohann, Ludger

2011-01-01

A total of 30 chloroform and methanol extracts from the following endemic Soqotran plants Acridocarpus socotranus Olive, Boswellia socotranao Balf.fil, Boswellia elongata Balf. fil., Caralluma socotrana N. Br, Cephalocroton socotranus Balf.f, Croton socotranus Balf. fil.., Dendrosicycos socotrana Balf.f., Dorstenia gigas Schweinf. ex Balf. fil., Eureiandra balfourii Cogn. & Balf. fil., Kalanchoe farinaceae Balf.f, Limonium sokotranum (Vierh) Radcl. Sm), Oldenlandia pulvinata, Pulicaria diversifolia (Balf. and Pulicaria stephanocarpa Balf. were screened for their acetylcholinesterase inhibitory activity by using in vitro Ellman method at 50 and 200 µg/ml concentrations. Chloroform extracts of Croton socotranus, Boswellia socotrana, Dorstenia gigas, and Pulicaria stephanocarpa as well as methanol extracts of Eureiandra balfourii exhibited inhibitory activities higher than 50 % at concentration of 200 µg. At a concentrations of 50 µg, the chloroform extract of Croton socotranus exhibited an inhibition of 40.6 %.

Molecular determinants for FMN-binding in Desulfovibrio gigas flavoredoxin.

PubMed

Broco, Manuela; Soares, Cláudio M; Oliveira, Solange; Mayhew, Stephen G; Rodrigues-Pousada, Claudina

2007-09-18

Flavoredoxin participates in Desulfovibrio gigas thiosulfate reduction pathway. Its 3-dimensional model was generated allowing the oxidized riboflavin-5'-phosphate (FMN) site to be predicted. Residues likely to be involved in FMN-binding were identified (N29, W35, T56, K92, H131 and F164) and mutated to alanine. Fluorescence titration with apoprotein showed that FMN is strongly bound in the wild-type protein. Comparison of K(d) values for mutants suggests that interactions with the phosphate group of FMN, contribute more to binding than the interactions with the isoalloxazine ring. The redox potential of bound FMN determined for wild-type and mutants revealed shifts to less negative values. These findings were correlated with the protein structure in order to contribute to a better understanding of the structure-function relationships in flavoredoxin.

Denman Island disease in Washington State, USA: distribution and prevalence in Pacific and Olympia oysters.

PubMed

Elston, Ralph; Friedman, Carolyn; Gustafson, Lori; Meyer, Gary; Rogers, Russell

2015-05-21

We sampled over 2400 wild, feral, and cultured Pacific oysters Crassostrea gigas and Olympia oysters Ostrea lurida in Washington State, USA, from 2002 to 2006 to estimate the prevalence of infection with Mikrocytos mackini, the causative agent of Denman Island disease. Both histology and qualitative PCR methods were used. Estimates of true prevalence of M. mackini infection in C. gigas, after accounting for imperfect test sensitivity, ranged from mean values of 0 to 10.0% by histology and 0 to 8.4% based on pooled PCR samples. M. mackini was not detected in any of the O. lurida samples. Results suggest a lower prevalence of the pathogen and severity of this oyster disease in Washington than that indicated in previous reports from British Columbia, Canada, potentially attributable to higher seawater temperatures in the Washington sample locations.

Corrosion Effects on the Fatigue Crack Propagation of Giga-Grade Steel and its Heat Affected Zone in pH Buffer Solutions for Automotive Application

NASA Astrophysics Data System (ADS)

Lee, H. S.

2018-03-01

Corrosion fatigue crack propagation test was conducted of giga-grade steel and its heat affected zone in pH buffer solutions, and the results were compared with model predictions. Pure corrosion effect on fatigue crack propagation, particularly, in corrosive environment was evaluated by means of the modified Forman equation. As shown in results, the average corrosion rate determined from the ratio of pure corrosion induced crack length to entire crack length under a cycle load were 0.11 and 0.37 for base metal and heat affected zone, respectively, with load ratio of 0.5, frequency of 0.5 and pH 10.0 environment. These results demonstrate new interpretation methodology for corrosion fatigue crack propagation enabling the pure corrosion effects on the behavior to be determined.

Moissanite anvil cell design for Giga-Pascal nuclear magnetic resonance.

PubMed

Meier, Thomas; Herzig, Tobias; Haase, Jürgen

2014-04-01

A new design of a non-magnetic high-pressure anvil cell for nuclear magnetic resonance (NMR) experiments at Giga-Pascal pressures is presented, which uses a micro-coil inside the pressurized region for high-sensitivity NMR. The comparably small cell has a length of 22 mm and a diameter of 18 mm, so it can be used with most NMR magnets. The performance of the cell is demonstrated with external-force vs. internal-pressure experiments, and the cell is shown to perform well at pressures up to 23.5 GPa using 800 μm 6H-SiC large cone Boehler-type anvils. (1)H, (23)Na, (27)Al, (69)Ga, and (71)Ga NMR test measurements are presented, which show a resolution of better than 4.5 ppm, and an almost maximum possible signal-to-noise ratio.

The sense of hearing in the Pacific oyster, Magallana gigas

PubMed Central

Charifi, Mohcine; Sow, Mohamedou; Ciret, Pierre; Benomar, Soumaya

2017-01-01

There is an increasing concern that anthropogenic noise could have a significant impact on the marine environment, but there is still insufficient data for most invertebrates. What do they perceive? We investigated this question in oysters Magallana gigas (Crassostrea gigas) using pure tone exposures, accelerometer fixed on the oyster shell and hydrophone in the water column. Groups of 16 oysters were exposed to quantifiable waterborne sinusoidal sounds in the range of 10 Hz to 20 kHz at various acoustic energies. The experiment was conducted in running seawater using an experimental flume equipped with suspended loudspeakers. The sensitivity of the oysters was measured by recording their valve movements by high-frequency noninvasive valvometry. The tests were 3 min tone exposures including a 70 sec fade-in period. Three endpoints were analysed: the ratio of responding individuals in the group, the resulting changes of valve opening amplitude and the response latency. At high enough acoustic energy, oysters transiently closed their valves in response to frequencies in the range of 10 to <1000 Hz, with maximum sensitivity from 10 to 200 Hz. The minimum acoustic energy required to elicit a response was 0.02 m∙s-2 at 122 dBrms re 1 μPa for frequencies ranging from 10 to 80 Hz. As a partial valve closure cannot be differentiated from a nociceptive response, it is very likely that oysters detect sounds at lower acoustic energy. The mechanism involved in sound detection and the ecological consequences are discussed. PMID:29069092

Characterization of microbiota in Arapaima gigas intestine and isolation of potential probiotic bacteria.

PubMed

do Vale Pereira, G; da Cunha, D G; Pedreira Mourino, J L; Rodiles, A; Jaramillo-Torres, A; Merrifield, D L

2017-11-01

The aim of this study was to determine the intestinal microbiota of pirarucu (Arapaima gigas) in different growth stages (adult and fingerlings) and to isolate and identify potential probiotic bacteria. High-throughput sequencing analysis of the intestinal contents revealed that the majority of sequences belonged to the Proteobacteria, Fusobacteria and Firmicutes phyla. At the genus level, the greatest number of sequences belonged to Bradyrhizobium in adult fish, while Cetobacterium was the most abundant in juvenile fish. Twenty-three lactic-acid bacteria (LABs) were isolated on MRS agar from healthy juvenile fish. The isolates were tested in vitro for probiotic properties. Two isolates (identified as strains of Lactococcus lactis subsp. lactis and Enterococcus faecium) displayed antagonism against all 10 pathogens tested, were nonhaemolytic and maintained good viability for at least 3 weeks when supplemented to fish diets. The presence of a number of antibiotic resistance genes (ARGs), conferring resistance to erythromycin, tetracycline and chloramphenicol, was investigated by PCR. The absence of ARGs investigated the potential to antagonize pathogens, and favourable growth and survival characteristics indicate that these autochthonous isolates have the potential to be considered probiotics, which will be studied in future in vivo experiments. This study has demonstrated, for the first time, the normal microbiota in the A. gigas intestine during different life stages and the presence of LAB strains. It also demonstrated LAB antibiotic resistance and antagonistic behaviour against pathogens isolated from the same fish. © 2017 The Society for Applied Microbiology.

Demography of the ecosystem engineer Crassostrea gigas, related to vertical reef accretion and reef persistence

NASA Astrophysics Data System (ADS)

Walles, Brenda; Mann, Roger; Ysebaert, Tom; Troost, Karin; Herman, Peter M. J.; Smaal, Aad C.

2015-03-01

Marine species characterized as structure building, autogenic ecosystem engineers are recognized worldwide as potential tools for coastal adaptation efforts in the face of sea level rise. Successful employment of ecosystem engineers in coastal protection largely depends on long-term persistence of their structure, which is in turn dependent on the population dynamics of the individual species. Oysters, such as the Pacific oyster (Crassostrea gigas), are recognized as ecosystem engineers with potential for use in coastal protection. Persistence of oyster reefs is strongly determined by recruitment and shell production (growth), processes facilitated by gregarious settlement on extant shell substrate. Although the Pacific oyster has been introduced world-wide, and has formed dense reefs in the receiving coastal waters, the population biology of live oysters and the quantitative mechanisms maintaining these reefs has rarely been studied, hence the aim of the present work. This study had two objectives: (1) to describe the demographics of extant C. gigas reefs, and (2) to estimate vertical reef accretion rates and carbonate production in these oyster reefs. Three long-living oyster reefs (>30 years old), which have not been exploited since their first occurrence, were examined in the Oosterschelde estuary in the Netherlands. A positive reef accretion rate (7.0-16.9 mm year-1 shell material) was observed, consistent with self-maintenance and persistent structure. We provide a framework to predict reef accretion and population persistence under varying recruitment, growth and mortality scenarios.

First-pass metabolism of decursin, a bioactive compound of Angelica gigas, in rats.

PubMed

Park, Hyun Seo; Kim, Byunghyun; Oh, Ju-Hee; Kim, Young Choong; Lee, Young-Joo

2012-06-01

Decursin is considered the major bioactive compound of Angelica gigas roots, a popular Oriental herb and dietary supplement. In this study, the pharmacokinetics of decursin and its active metabolite, decursinol, were evaluated after the administration of decursin in rats. The plasma concentration of decursin decreased rapidly, with an initial half-life of 0.05 h. It was not detectable at 1 h after intravenous administration at an area under the plasma concentration-time curve of 1.20 µg · mL-1·h, whereas the concentration of decursinol increased rapidly reaching a maximum concentration of 2.48 µg · mL-1 at the time to maximum plasma concentration of 0.25 h and an area under the plasma concentration-time curve of 5.23 µg · mL-1·h. Interestingly, after oral administration of decursin, only decursinol was present in plasma, suggesting an extensive hepatic first-pass metabolism of decursin. The extremely low bioavailability of decursin after its administration via the hepatic portal vein (the fraction of dose escaping first-pass elimination in the liver, FH = 0.11) is indicative of extensive hepatic first-pass metabolism of decursin, which was confirmed by a tissue distribution study. These findings suggest that decursin is not directly associated with the bioactivity of A. gigas and that it may work as a type of natural prodrug of decursinol. Georg Thieme Verlag KG Stuttgart · New York.

Physicochemical characterization and toxicity of decursin and their derivatives from Angelica gigas.

PubMed

Mahat, Bimit; Chae, Jung-Woo; Baek, In-Hwan; Song, Gyu-Yong; Song, Jin-Sook; Cho, Seong-Kwon; Kwon, Kwang-Il

2012-01-01

Angelica gigas NAKAI is used to treat dysmenorrhea, amenorrhea, menopause, abdominal pain, injuries, migraine, and arthritis. The present study provided a physicochemical and toxicological characterization of compounds in A. gigas NAKAI (decursin, decursinol angelate, diketone decursin, ether decursin, epoxide decursin and oxim decursin). Diketone decursin (173.16 μg/mL) and epoxide decursin (122.12 μg/mL) exhibited >100 μg/mL kinetic solubility after applying nephelometry, suggesting a highly soluble compound. The Student’s t-test revealed significant differences in the pKa ranges of the compounds by automatic titration from capillary electrophoresis (p<0.05). Diketone decursin, epoxide decursin and oxim decursin might be formulated into an oral dosage form (log P: 0-3) by an automatic titration analysis. A parallel artificial membrane permeability assay demonstrated permeability coefficients of <10 x 10⁻⁶ cm/s for all of the compounds, suggesting poor permeability. Ether decursin exhibited a toxic effect after being applied to mouse (NIH 3T3, EC₅₀: 57.9 μM) and human (HT-29, EC₅₀: 36.1 μM; Hep-G2, EC₅₀: 4.92 μM) cells. Additionally, epoxide and oxim decursin were toxic through acute oral toxicity (four and three deaths of Institute of Cancer Research (ICR) mice) and mutation toxicity testing by applying Salmonella typhimurium cells with and without S9. Although diketone decursin exhibited less permeability, it is potentially valuable pharmacological compound that should be investigated.

Impacts of ocean acidification on gene expression and biomineralisation in the Pacific oyster Crassostrea gigas Thunberg, 1793

NASA Astrophysics Data System (ADS)

Bagusche, F.; Pouvreau, S.; Trueman, C.; Long, S.; Hauton, C.

2012-04-01

The published evidence of impacts of ocean acidification and on marine calcifiers has emphasized the need to understand the molecular mechanisms of biomineralisation. Crassostrea gigas is an ideal organism to examine these processes as: 1) the hatchery rearing of larval stages is well constrained, 2) studies have established an ontogenetic switch in deposition of carbonate polymorphs from aragonite in larval shells to calcite in adults and 3) it is a globally-important commercial species. Research summarized in this presentation will identify some of the molecular mechanisms involved in calcification processes during ontogeny of Crassostrea gigas, as well as possible impacts of changes in environmental conditions such as temperature and pH. Data will be presented from a quantitative real-time PCR study of the changes in gene expression during development in different environments. Additionally scanning electron microscopy and infrared spectroscopy analyses of shell microstructures and composition will be summarised to correlate changes in gene expression with end-point differences in shell structure. Preliminary results suggest that changes in the environmental conditions lead to differences in expression patterns of genes involved in biomineralisation processes. The combined effects of ambient seawater temperature and low pH show the greatest negative effect on larval shell development, identified as malformations, eroded shell surfaces and a significant decrease in shell size. However, the effect of higher seawater temperature seems to amend the effects of ocean acidification on larval shell development.

Rapid expansion of the invasive oyster Crassostrea gigas at its northern distribution limit in Europe: Naturally dispersed or introduced?

PubMed Central

Anglès d’Auriac, Marc B.; Norling, Pia; Lapègue, Sylvie; Staalstrøm, André; Hjermann, Dag Ø.; Thaulow, Jens

2017-01-01

The Pacific oyster, Crassostrea gigas, was introduced to Europe for aquaculture purposes, and has had a rapid and unforeseen northward expansion in northern Europe. The recent dramatic increase in number of C. gigas populations along the species’ northern distribution limit has questioned the efficiency of Skagerrak as a dispersal barrier for transport and survival of larvae. We investigated the genetic connectivity and possible spreading patterns between Pacific oyster populations on the southern Norwegian coast (4 localities) and Swedish and Danish populations by means of DNA microsatellite analysis of adult oysters, and by simulating larvae drift. In the simulations we used a 3D oceanographic model to explore the influence of recent climate change (1990–2010) on development, survival, and successful spreading of Danish and Swedish Pacific oyster larvae to Norwegian coastal waters. The simulations indicated adequate temperature conditions for development, survival, and settlement of larvae across the Skagerrak in warm years since 2000. However, microsatellite genotyping revealed genetic differences between the Norwegian populations, and between the Norwegian populations and the Swedish and Danish populations, the latter two populations being more similar. This patchwork pattern of genetic dissimilarity among the Norwegian populations points towards multiple local introduction routes rather than the commonly assumed unidirectional entry of larvae drifted from Denmark and Sweden. Alternative origins of introduction and implications for management, such as forecasting and possible mitigation actions, are discussed. PMID:28486520

Identification of molecular and physiological responses to chronic environmental challenge in an invasive species: the Pacific oyster, Crassostrea gigas

PubMed Central

Clark, Melody S; Thorne, Michael A S; Amaral, Ana; Vieira, Florbela; Batista, Frederico M; Reis, João; Power, Deborah M

2013-01-01

Understanding the environmental responses of an invasive species is critical in predicting how ecosystem composition may be transformed in the future, especially under climate change. In this study, Crassostrea gigas, a species well adapted to the highly variable intertidal environment, was exposed to the chronic environmental challenges of temperature (19 and 24°C) and pH (ambient seawater and a reduction of 0.4 pH units) in an extended 3-month laboratory-based study. Physiological parameters were measured (condition index, shell growth, respiration, excretion rates, O:N ratios, and ability to repair shell damage) alongside molecular analyses. Temperature was by far the most important stressor, as demonstrated by reduced condition indexes and shell growth at 24°C, with relatively little effect detected for pH. Transcriptional profiling using candidate genes and SOLiD sequencing of mantle tissue revealed that classical “stress” genes, previously reported to be upregulated under acute temperature challenges, were not significantly expressed in any of the treatments, emphasizing the different response between acute and longer term chronic stress. The transcriptional profiling also elaborated on the cellular responses underpinning the physiological results, including the identification of the PI3K/AKT/mTOR pathway as a potentially novel marker for chronic environmental challenge. This study represents a first attempt to understand the energetic consequences of cumulative thermal stress on the intertidal C. gigas which could significantly impact on coastal ecosystem biodiversity and function in the future. PMID:24223268

Effects of Antifouling Biocides on Molecular and Biochemical Defense System in the Gill of the Pacific Oyster Crassostrea gigas.

PubMed

Park, Mi Seon; Kim, Young Dae; Kim, Bo-Mi; Kim, Youn-Jung; Kim, Jang Kyun; Rhee, Jae-Sung

2016-01-01

Antifouling biocides such as organotin compounds and their alternatives are potent toxicants in marine ecosystems. In this study, we employed several molecular and biochemical response systems of the Pacific oyster Crassostrea gigas to understand a potential mode of action of antifouling biocides (i.e. tributyltin (TBT), diuron and irgarol) after exposure to different concentrations (0.01, 0.1, and 1 μg L-1) for 96 h. As a result, all the three antifouling biocides strongly induced the antioxidant defense system. TBT reduced both enzymatic activity and mRNA expression of Na+/K+-ATPase and acetylcholinesterase (AChE). Lower levels of both Na+/K+-ATPase activity and AChE mRNA expression were observed in the diuron-exposed oysters compared to the control, while the irgarol treatment reduced only the transcriptional expression of AChE gene. We also analyzed transcript profile of heat shock protein (Hsp) superfamily in same experimental conditions. All antifouling biocides tested in this study significantly modulated mRNA expression of Hsp superfamily with strong induction of Hsp70 family. Taken together, overall results indicate that representative organotin TBT and alternatives have potential hazardous effects on the gill of C. gigas within relatively short time period. Our results also suggest that analyzing a series of molecular and biochemical parameters can be a way of understanding and uncovering the mode of action of emerging antifouling biocides. In particular, it was revealed that Pacific oysters have different sensitivities depend on the antifouling biocides.

A New Type of Metal-Binding Site in Cobalt- And Zinc-Containing Adenylate Kinases Isolated From Sulfate-Reducers D. Gigas And D. Desulfuricans ATCC 27774

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gavel, O.Y.; Bursakov, S.A.; Rocco, G.Di

2009-05-18

Adenylate kinase (AK) mediates the reversible transfer of phosphate groups between the adenylate nucleotides and contributes to the maintenance of their constant cellular level, necessary for energy metabolism and nucleic acid synthesis. The AK were purified from crude extracts of two sulfate-reducing bacteria (SRB), Desulfovibrio (D.) gigas NCIB 9332 and Desulfovibrio desulfuricans ATCC 27774, and biochemically and spectroscopically characterized in the native and fully cobalt- or zinc-substituted forms. These are the first reported adenylate kinases that bind either zinc or cobalt and are related to the subgroup of metal-containing AK found, in most cases, in Gram-positive bacteria. The electronic absorptionmore » spectrum is consistent with tetrahedral coordinated cobalt, predominantly via sulfur ligands, and is supported by EPR. The involvement of three cysteines in cobalt or zinc coordination was confirmed by chemical methods. Extended X-ray absorption fine structure (EXAFS) indicate that cobalt or zinc are bound by three cysteine residues and one histidine in the metal-binding site of the 'LID' domain. The sequence {sup 129}Cys-X{sub 5}-His-X{sub 15}-Cys-X{sub 2}-Cys of the AK from D. gigas is involved in metal coordination and represents a new type of binding motif that differs from other known zinc-binding sites of AK. Cobalt and zinc play a structural role in stabilizing the LID domain.« less

Structural studies on Desulfovibrio gigas cytochrome c3 by two-dimensional 1H-nuclear-magnetic-resonance spectroscopy.

PubMed Central

Piçarra-Pereira, M A; Turner, D L; LeGall, J; Xavier, A V

1993-01-01

Several aromatic amino acid residues and haem resonances in the fully reduced form of Desulfovibrio gigas cytochrome c3 are assigned, using two-dimensional 1H n.m.r., on the basis of the interactions between the protons of the aromatic amino acids and the haem protons as well as the intrahaem distances known from the X-ray structure [Kissinger (1989) Ph.D. Thesis, Washington State University]. The interhaem interactions observed in the n.m.r. spectra are in full agreement with the D. gigas X-ray structure and also with the n.m.r. data from Desulfovibrio vulgaris (Hildenborough) [Turner, Salgueiro, LeGall and Xavier (1992) Eur. J. Biochem. 210, 931-936]. The good correlation between the calculated ring-current shifts and the observed chemical shifts strongly supports the present assignments. Observation of the two-dimensional nuclear-Overhauser-enhancement spectra of the protein in the reduced, intermediate and fully oxidized stages led to the ordering of the haems in terms of their midpoint redox potentials and their identification in the X-ray structure. The first haem to oxidize is haem I, followed by haems II, III and IV, numbered according to the Cys ligand positions in the amino acid sequences [Mathews (1985) Prog. Biophys. Mol. Biol. 54, 1-56]. Although the haem core architecture is the same for the different Desulfovibrio cytochromes c3, the order of redox potentials is different. PMID:8397514

How annual course of photoperiod shapes seasonal behavior of diploid and triploid oysters, Crassostrea gigas

PubMed Central

Payton, Laura; Sow, Mohamedou; Massabuau, Jean-Charles; Ciret, Pierre

2017-01-01

In this work, we study if ploidy (i.e. number of copies of chromosomes) in the oyster Crassostrea gigas may introduce differences in behavior and in its synchronization by the annual photoperiod. To answer to the question about the effect of the seasonal course of the photoperiod on the behavior of C. gigas according to its ploidy, we quantified valve activity by HFNI valvometry in situ for 1 year in both diploid and triploid oysters. Chronobiological analyses of daily, tidal and lunar rhythms were performed according the annual change of the photoperiod. In parallel, growth and gametogenesis status were measured and spawning events were detected by valvometry. The results showed that triploids had reduced gametogenesis, without spawning events, and approximately three times more growth than diploids. These differences in physiological efforts could explain the result that photoperiod (daylength and/or direction of daylength) differentially drives and modulates seasonal behavior of diploid and triploid oysters. Most differences were observed during long days (spring and summer), where triploids showed longer valve opening duration but lower opening amplitude, stronger daily rhythm and weaker tidal rhythm. During this period, diploids did major gametogenesis and spawning whereas triploids did maximal growth. Differences were also observed in terms of moonlight rhythmicity and neap-spring tidal cycle rhythmicity. We suggest that the seasonal change of photoperiod differentially synchronizes oyster behavior and biological rhythms according to physiological needs based on ploidy. PMID:29020114

The sense of hearing in the Pacific oyster, Magallana gigas.

PubMed

Charifi, Mohcine; Sow, Mohamedou; Ciret, Pierre; Benomar, Soumaya; Massabuau, Jean-Charles

2017-01-01

There is an increasing concern that anthropogenic noise could have a significant impact on the marine environment, but there is still insufficient data for most invertebrates. What do they perceive? We investigated this question in oysters Magallana gigas (Crassostrea gigas) using pure tone exposures, accelerometer fixed on the oyster shell and hydrophone in the water column. Groups of 16 oysters were exposed to quantifiable waterborne sinusoidal sounds in the range of 10 Hz to 20 kHz at various acoustic energies. The experiment was conducted in running seawater using an experimental flume equipped with suspended loudspeakers. The sensitivity of the oysters was measured by recording their valve movements by high-frequency noninvasive valvometry. The tests were 3 min tone exposures including a 70 sec fade-in period. Three endpoints were analysed: the ratio of responding individuals in the group, the resulting changes of valve opening amplitude and the response latency. At high enough acoustic energy, oysters transiently closed their valves in response to frequencies in the range of 10 to <1000 Hz, with maximum sensitivity from 10 to 200 Hz. The minimum acoustic energy required to elicit a response was 0.02 m∙s-2 at 122 dBrms re 1 μPa for frequencies ranging from 10 to 80 Hz. As a partial valve closure cannot be differentiated from a nociceptive response, it is very likely that oysters detect sounds at lower acoustic energy. The mechanism involved in sound detection and the ecological consequences are discussed.

How annual course of photoperiod shapes seasonal behavior of diploid and triploid oysters, Crassostrea gigas.

PubMed

Payton, Laura; Sow, Mohamedou; Massabuau, Jean-Charles; Ciret, Pierre; Tran, Damien

2017-01-01

In this work, we study if ploidy (i.e. number of copies of chromosomes) in the oyster Crassostrea gigas may introduce differences in behavior and in its synchronization by the annual photoperiod. To answer to the question about the effect of the seasonal course of the photoperiod on the behavior of C. gigas according to its ploidy, we quantified valve activity by HFNI valvometry in situ for 1 year in both diploid and triploid oysters. Chronobiological analyses of daily, tidal and lunar rhythms were performed according the annual change of the photoperiod. In parallel, growth and gametogenesis status were measured and spawning events were detected by valvometry. The results showed that triploids had reduced gametogenesis, without spawning events, and approximately three times more growth than diploids. These differences in physiological efforts could explain the result that photoperiod (daylength and/or direction of daylength) differentially drives and modulates seasonal behavior of diploid and triploid oysters. Most differences were observed during long days (spring and summer), where triploids showed longer valve opening duration but lower opening amplitude, stronger daily rhythm and weaker tidal rhythm. During this period, diploids did major gametogenesis and spawning whereas triploids did maximal growth. Differences were also observed in terms of moonlight rhythmicity and neap-spring tidal cycle rhythmicity. We suggest that the seasonal change of photoperiod differentially synchronizes oyster behavior and biological rhythms according to physiological needs based on ploidy.

Ostreid herpesvirus type 1 genomic diversity in wild populations of Pacific oyster Crassostrea gigas from Italian coasts.

PubMed

Burioli, E A V; Prearo, M; Riina, M V; Bona, M C; Fioravanti, M L; Arcangeli, G; Houssin, M

2016-06-01

Ostreid herpesvirus 1 (OsHV-1) is a significant pathogen affecting the young Pacific oyster Crassostrea gigas, worldwide. A new variant, OsHV-1 μVar, has been associated with recurrent mortality events in Europe since 2008. Epidemiological data collection is key for global risk assessment; however little is known about health status and genotypes present in European wild oyster beds. Most studies to date have involved only cultivated individuals during mortality events, and reported low genotype diversity. With this study, conducted along the Italian coasts, we investigated for the first time the presence of OsHV-1 in European natural oyster beds. Analysis of three genomic regions revealed the presence of at least nine different genotypes, including two variants close to the OsHV-1 reference, known since the early 1990s but with no European record reported since 2010, and highlights relevant genotype diversity in natural environment. Phylogenetic analysis distinguished two distinct clusters and geographical distribution of genotypes, with the exception of a variant very closely related to the μVar, which appeared the single genotype present in all the Adriatic sites. Interestingly, these wild symptom free populations could represent, in Europe, an accessible alternative to the import of OsHV-1-resistant oyster strains from the East Pacific, the native area of C. gigas, avoiding the high-risk of non-native marine species and new pathogen introductions. Copyright © 2016 Elsevier Inc. All rights reserved.

GENETIC CHARACTERIZATION OF A BURROWING SHRIMP (NEOTRYPAEA CALIFORNIENSIS)

EPA Science Inventory

Ghost shrimp, (Neotypaea californiensis) are burrowers, whose bioturbation and sediment destabilizations have a negative effect on mariculture of the commercially important oyster (Crassostrea gigas). Oyster farmers in Washington and Oregon estuaries have been poisoning these shr...

GigaGauss solenoidal magnetic field inside bubbles excited in under-dense plasma

PubMed Central

Lécz, Zs.; Konoplev, I. V.; Seryi, A.; Andreev, A.

2016-01-01

This paper proposes a novel and effective method for generating GigaGauss level, solenoidal quasi-static magnetic fields in under-dense plasma using screw-shaped high intensity laser pulses. This method produces large solenoidal fields that move with the driving laser pulse and are collinear with the accelerated electrons. This is in contrast with already known techniques which rely on interactions with over-dense or solid targets and generates radial or toroidal magnetic field localized at the stationary target. The solenoidal field is quasi-stationary in the reference frame of the laser pulse and can be used for guiding electron beams. It can also provide synchrotron radiation beam emittance cooling for laser-plasma accelerated electron and positron beams, opening up novel opportunities for designs of the light sources, free electron lasers, and high energy colliders based on laser plasma acceleration. PMID:27796327

GigaGauss solenoidal magnetic field inside bubbles excited in under-dense plasma

NASA Astrophysics Data System (ADS)

Lécz, Zs.; Konoplev, I. V.; Seryi, A.; Andreev, A.

2016-10-01

This paper proposes a novel and effective method for generating GigaGauss level, solenoidal quasi-static magnetic fields in under-dense plasma using screw-shaped high intensity laser pulses. This method produces large solenoidal fields that move with the driving laser pulse and are collinear with the accelerated electrons. This is in contrast with already known techniques which rely on interactions with over-dense or solid targets and generates radial or toroidal magnetic field localized at the stationary target. The solenoidal field is quasi-stationary in the reference frame of the laser pulse and can be used for guiding electron beams. It can also provide synchrotron radiation beam emittance cooling for laser-plasma accelerated electron and positron beams, opening up novel opportunities for designs of the light sources, free electron lasers, and high energy colliders based on laser plasma acceleration.

Phenoloxidase activity in larval and juvenile homogenates and adult plasma and haemocytes of bivalve molluscs.

PubMed

Luna-González, Antonio; Maeda-Martínez, Alfonso N; Vargas-Albores, Francisco; Ascencio-Valle, Felipe; Robles-Mungaray, Miguel

2003-10-01

Phenoloxidase (PO) activity was studied in larval and juvenile homogenates and in the plasma and haemocytes of adult Crassostrea gigas, Argopecten ventricosus, Nodipecten subnodosus, and Atrina maura. Samples were tested for the presence of PO activity by incubation with the substrate L-3, 4-dihydroxyphenylalanine using trypsin, alpha-chymotrypsin, laminarin, lipopolysaccharides (LPS), and sodium dodecyl sulphate (SDS) to elicit activation of prophenoloxidase (proPO) system. PO activity was not detected in larval homogenate. In juvenile homogenate, PO activity was found only in C. gigas and N. subnodosus. PO activity was present in adult samples and was enhanced by elicitors in the plasma of all species tested, but in haemocyte lysate supernatant (HLS) of only N. subnodosus. Activation of proPO by laminarin was suppressed by a protease inhibitor cocktail (P-2714) in plasma and HLS of all species tested.

Decursin from Angelica gigas mitigates amnesia induced by scopolamine in mice.

PubMed

Kang, So Young; Lee, Ki Yong; Park, Mi Jung; Kim, Young Chul; Markelonis, George J; Oh, Tae H; Kim, Young Choong

2003-01-01

We previously reported that a total methanolic extract of the underground part of Angelica gigas Nakai (Umbelliferae) (here-in-after abbreviated AG) significantly inhibited acetylcholinesterase (AChE) activity. We characterized 12 coumarin derivatives including both decursin and decursinol from extracts of AG. In this study, we evaluated the anti-amnestic activity of decursin, a major coumarin constituent isolated from AG, in vivo using ICR mice with amnesia induced by scopolamine (1 mg/kg body weight, s.c.). Decursin, when administered to mice at 1 and 5 mg/kg body weight i.p., significantly ameliorated scopolamine-induced amnesia as measured in both the passive avoidance test and the Morris water maze test. Moreover, decursin significantly inhibited AChE activity by 34% in the hippocampus of treated mice. These results indicate that decursin may exert anti-amnestic activity in vivo through inhibition of AChE activity in the hippocampus.

Rare occurrence of heart lesions in Pacific oysters Crassostrea gigas caused by an unknown bacterial infection.

PubMed

Meyer, Gary R; Lowe, Geoffrey J; Bower, Susan M

2017-09-20

On rare occasions, small cream-coloured cysts have been observed in the heart and pericardial cavity of Pacific oysters Crassostrea gigas from British Columbia, Canada. Histopathology revealed the presence of large colonies of bacteria (up to 800 µm in diameter) causing significant host response and hypertrophy of the heart epithelium. The causative bacteria were characterized as follows: Gram-negative, coccoid to small rod-shaped, typically <1.5 µm in size, cell walls highly endowed with surface fimbriae and division via binary fission. Although these bacteria shared some morphological characteristics with the order Rickettsiales, they did not require an intracellular existence for multiplication. Unfortunately, a cultured isolate was not available, and a retrospective attempt to further characterize the bacteria using DNA sequence analysis of a fragment from the 16S rDNA region proved to be uninformative.

Bacteriophage as models for virus removal from Pacific oysters (Crassostrea gigas) during re-laying.

PubMed Central

Humphrey, T. J.; Martin, K.

1993-01-01

A study was undertaken to examine the feasibility of using naturally-occurring bacteriophages to assess the impact of re-laying on levels of viral contamination in Crassostrea gigas, the Pacific oyster. Two phages were chosen. One, male-specific (F+), was enumerated using Salmonella typhimurium. The other, a somatic phage, was detected using an, as yet, uncharacterized Escherichia coli. Investigations, using a variety of re-laying sites, demonstrated that numbers of F+ phage in oyster tissue declined more rapidly than those of somatic phage. For example, in oysters placed in commercially-used sea water ponds, F+ phage reached undetectable levels within 2-3 weeks, whereas somatic phage could still be detected 5 weeks after re-laying. The studies suggest that F+ phage may not be a suitable indicator for virus removal and that somatic phage may be better suited to this role. PMID:8405159

A Parallel Multigrid Solver for Viscous Flows on Anisotropic Structured Grids

NASA Technical Reports Server (NTRS)

Prieto, Manuel; Montero, Ruben S.; Llorente, Ignacio M.; Bushnell, Dennis M. (Technical Monitor)

2001-01-01

This paper presents an efficient parallel multigrid solver for speeding up the computation of a 3-D model that treats the flow of a viscous fluid over a flat plate. The main interest of this simulation lies in exhibiting some basic difficulties that prevent optimal multigrid efficiencies from being achieved. As the computing platform, we have used Coral, a Beowulf-class system based on Intel Pentium processors and equipped with GigaNet cLAN and switched Fast Ethernet networks. Our study not only examines the scalability of the solver but also includes a performance evaluation of Coral where the investigated solver has been used to compare several of its design choices, namely, the interconnection network (GigaNet versus switched Fast-Ethernet) and the node configuration (dual nodes versus single nodes). As a reference, the performance results have been compared with those obtained with the NAS-MG benchmark.

Moissanite anvil cell design for giga-pascal nuclear magnetic resonance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meier, Thomas; Herzig, Tobias; Haase, Jürgen

2014-04-15

A new design of a non-magnetic high-pressure anvil cell for nuclear magnetic resonance (NMR) experiments at Giga-Pascal pressures is presented, which uses a micro-coil inside the pressurized region for high-sensitivity NMR. The comparably small cell has a length of 22 mm and a diameter of 18 mm, so it can be used with most NMR magnets. The performance of the cell is demonstrated with external-force vs. internal-pressure experiments, and the cell is shown to perform well at pressures up to 23.5 GPa using 800 μm 6H-SiC large cone Boehler-type anvils. {sup 1}H, {sup 23}Na, {sup 27}Al, {sup 69}Ga, and {supmore » 71}Ga NMR test measurements are presented, which show a resolution of better than 4.5 ppm, and an almost maximum possible signal-to-noise ratio.« less

Ultrasonic Corrosion Fatigue Behavior of High Strength Austenitic Stainless Steels

NASA Astrophysics Data System (ADS)

Ebara, R.; Yamaguchi, Y.; Kanei, D.; Yamamoto, Y.

Ultrasonic corrosion fatigue tests were conducted for high strength austenitic stainless steels such as YUS270 and SUS304N2 in 3%NaCl aqueous solution. The reduction of giga-cycle corrosion fatigue strength of YUS270 and SUS304N2 was not observed at all, while the reduction of corrosion fatigue life was observed at higher stress amplitude. Corrosion pit was observed on corrosion fatigue crack initiation area. Striation was predominantly observed on crack propagation area in air and in 3% NaCl aqueous solution. The reduction of corrosion fatigue strength of high strength austenitic stainless steels such as YUS270 and SUS304N2 is due to the corrosion pit formation at corrosion fatigue crack initiation area. It can be concluded that the higher the ultimate tensile strength of austenitic stainless steels the higher the giga-cycle corrosion fatigue strength in 3%NaCl aqueous solution is.

Giga-ohm seals on intracellular membranes: a technique for studying intracellular ion channels in intact cells.

PubMed

Jonas, E A; Knox, R J; Kaczmarek, L K

1997-07-01

A method is outlined for obtaining giga-ohm seals on intracellular membranes in intact cells. The technique employs a variant of the patch-clamp technique: a concentric electrode arrangement protects an inner patch pipette during penetration of the plasma membrane, after which a seal can be formed on an internal organelle membrane. Using this technique, successful recordings can be obtained with the same frequency as with conventional patch clamping. To localize the position of the pipette within cells, lipophilic fluorescent dyes are included in the pipette solution. These dyes stain the membrane of internal organelles during seal formation and can then be visualized by video-enhanced or confocal imaging. The method can detect channels activated by inositol trisphosphate, as well as other types of intracellular membrane ion channel activity, and should facilitate studies of internal membranes in intact neurons and other cell types.

Ecotoxicological evaluation of industrial port of Venice (Italy) sediment samples after a decontamination treatment.

PubMed

Libralato, Giovanni; Losso, Chiara; Arizzi Novelli, Alessandra; Citron, Marta; Della Sala, Stefano; Zanotto, Emanuele; Cepak, Franka; Volpi Ghirardini, Annamaria

2008-12-01

This work assesses the ecotoxicological effects of polluted sediment after a decontamination treatment process using a new sediment washing technique. Sediment samples were collected from four sites in Marghera Port industrial channels (Venice, Italy). Ecotoxicological evaluations were performed with Vibrio fischeri and Crassostrea gigas bioassays. Whole sediment and elutriate were deemed as the most suitable environmental matrices for this study. Toxicity scores developed in the Lagoon of Venice for V. fischeri on whole sediment and for C. gigas on elutriate were considered for the final ranking of samples. Ecotoxicological results showed that the treated sediment samples presented both acute and sub-chronic toxicities, which were mainly attributed to the presence of some remaining chemicals such as metals and polyaromatic hydrocarbons. The acute toxicity ranged from low to medium, while the sub-chronic one from absent to very high, suggesting that treated sediments could not be reused in direct contact with seawater.

Immune effects of HFO on European sea bass, Dicentrarchus labrax, and Pacific oyster, Crassostrea gigas.

PubMed

Bado-Nilles, Anne; Quentel, Claire; Auffret, Michel; Le Floch, Stéphane; Gagnaire, Béatrice; Renault, Tristan; Thomas-Guyon, Hélène

2009-07-01

The European sea bass, Dicentrarchus labrax, and the Pacific oyster, Crassostrea gigas, were exposed to a soluble fraction of heavy fuel oil for 5 and 9 days, respectively. The organisms were then transferred to non-contaminated seawater for 1 month. The bioaccumulation and elimination of PAHs in contaminated tissues were dissimilar between species. In fish, acenaphthene and naphthalene were detected and naphthalene was still detectable 30 days after the beginning of the recovery period. In oysters, on the other hand, pyrene and phenanthrene were bioaccumulated and 14 days after exposure no more PAHs were detected. Concerning innate immune parameters, the increase of haemolytic activity of the alternative complement pathway in fish and the reduction of phenoloxidase activity in oysters endured, respectively, 1 and 2 weeks in contaminated organisms. This indicates that these two enzymatic cascades could be quite useful for monitoring pollution by oil.

Cloning and localization of MCdef, a defensin from Manila clams (Ruditapes philippinarum).

PubMed

Adhya, Mausumi; Jeung, Hee-Do; Kang, Hyun-Sil; Choi, Kwang-Sik; Lee, Dong Sun; Cho, Moonjae

2012-01-01

A defensin-like peptide was previously detected in hemocytes of Manila clams (Ruditapes philippinarum). In the current study, we cloned and characterized this defensin, designated MCdef. Cloning produced a full-length gene sequence of 201 bp predicted to encode a 66-amino-acid precursor protein maturing to a 44-amino-acid residue. Amino acid sequence analysis showed that MCdef is similar to defensins from marine mollusks and ticks. Phylogenetic analysis suggested that MCdef is closely related to defensins from Mytilus galloprovincialis (Mediterranean mussel) and Crassostrea gigas (Pacific cupped oyster). The three-dimensional structure of MCdef was modeled using the solution structure of C. gigas defensin as a template. With the exception of three variable loop areas, the modeled structure of MCdef was identical to that of C. gigas defensin. MCdef antiserum was raised against a synthetic MCdef peptide and verified by Western blotting using recombinant MCdef. RT-PCR analysis demonstrated high levels of MCdef mRNA in hemocytes and adductor, foot, gill, mantle, palp, and siphon tissues of Vibrio tapetis-infected Manila clams, whereas in V. tapetis-uninfected Manila clams, the level of MCdef mRNA was low in adductor, palp, and siphon tissues and even lower in the other tested tissues. Immunohistochemical analysis revealed high MCdef expression was detected in the gill, the mantle, and the digestive tubules of the diverticulum of V. tapetis-infected Manila clams. Minimum inhibitory concentration (MIC) of the purified rMCdef was determined. MCdef showed highest activity against Streptococcus iniae and Staphylococcus aureus. Copyright © 2011 Elsevier Inc. All rights reserved.

Molecular analysis of bacterial microbiota associated with oysters (Crassostrea gigas and Crassostrea corteziensis) in different growth phases at two cultivation sites.

PubMed

Trabal, Natalia; Mazón-Suástegui, José M; Vázquez-Juárez, Ricardo; Asencio-Valle, Felipe; Morales-Bojórquez, Enrique; Romero, Jaime

2012-08-01

Microbiota presumably plays an essential role in inhibiting pathogen colonization and in the maintenance of health in oysters, but limited data exist concerning their different growth phases and conditions. We analyzed the bacterial microbiota composition of two commercial oysters: Crassostrea gigas and Crassostrea corteziensis. Differences in microbiota were assayed in three growth phases: post-larvae at the hatchery, juvenile, and adult at two grow-out cultivation sites. Variations in the microbiota were assessed by PCR analysis of the 16S rRNA gene in DNA extracted from depurated oysters. Restriction fragment length polymorphism (RFLP) profiles were studied using Dice's similarity coefficient (Cs) and statistical principal component analysis (PCA). The microbiota composition was determined by sequencing temperature gradient gel electrophoresis (TGGE) bands. The RFLP analysis of post-larvae revealed homology in the microbiota of both oyster species (Cs > 88 %). Dice and PCA analyses of C. corteziensis but not C. gigas showed differences in the microbiota according to the cultivation sites. The sequencing analysis revealed low bacterial diversity (primarily β-Proteobacteria, Firmicutes, and Spirochaetes), with Burkholderia cepacia being the most abundant bacteria in both oyster species. This study provides the first description of the microbiota in C. corteziensis, which was shown to be influenced by cultivation site conditions. During early growth, we observed that B. cepacia colonized and remained strongly associated with the two oysters, probably in a symbiotic host-bacteria relationship. This association was maintained in the three growth phases and was not altered by environmental conditions or the management of the oysters at the grow-out site.

Eupolybothrus cavernicolus Komerički & Stoev sp. n. (Chilopoda: Lithobiomorpha: Lithobiidae): the first eukaryotic species description combining transcriptomic, DNA barcoding and micro-CT imaging data

PubMed Central

2013-01-01

Abstract We demonstrate how a classical taxonomic description of a new species can be enhanced by applying new generation molecular methods, and novel computing and imaging technologies. A cave-dwelling centipede, Eupolybothrus cavernicolus Komerički & Stoev sp. n. (Chilopoda: Lithobiomorpha: Lithobiidae), found in a remote karst region in Knin, Croatia, is the first eukaryotic species for which, in addition to the traditional morphological description, we provide a fully sequenced transcriptome, a DNA barcode, detailed anatomical X-ray microtomography (micro-CT) scans, and a movie of the living specimen to document important traits of its ex-situ behaviour. By employing micro-CT scanning in a new species for the first time, we create a high-resolution morphological and anatomical dataset that allows virtual reconstructions of the specimen and subsequent interactive manipulation to test the recently introduced ‘cybertype’ notion. In addition, the transcriptome was recorded with a total of 67,785 scaffolds, having an average length of 812 bp and N50 of 1,448 bp (see GigaDB). Subsequent annotation of 22,866 scaffolds was conducted by tracing homologs against current available databases, including Nr, SwissProt and COG. This pilot project illustrates a workflow of producing, storing, publishing and disseminating large data sets associated with a description of a new taxon. All data have been deposited in publicly accessible repositories, such as GigaScience GigaDB, NCBI, BOLD, Morphbank and Morphosource, and the respective open licenses used ensure their accessibility and re-usability. PMID:24723752

Comprehensive HPTLC Fingerprinting for Quality Control of an Herbal Drug - The Case of Angelica gigas Root.

PubMed

Frommenwiler, Débora Arruda; Kim, Jonghwan; Yook, Chang-Soo; Tran, Thi Thu Trang; Cañigueral, Salvador; Reich, Eike

2018-04-01

The quality of herbal drugs is usually controlled using several tests recommended in a monograph. HPTLC is the method of choice for identification in many pharmacopoeias. If combined with a suitable reference material for comparison, HPTLC can provide information beyond identification and thus may simplify quality control. This paper describes, as a proof of concept, how HPTLC can be applied to define specifications for an herbal reference material and to control the quality of an herbal drug according to these specifications. Based on multiple batches of cultivated Angelica gigas root, a specific HPTLC method for identification was optimized. This method can distinguish 27 related species. It also can detect the presence of mixtures of A. gigas with two other Angelica species traded as "Dang gui" and is suitable as well for quantitative assessment of samples in a test for minimum content of the sum of decursin and decursinol angelate. The new concept of "comprehensive HPTLC fingerprinting" is proposed: HPTLC fingerprints (images), which are used for identification, are converted into peak profiles and the intensities of selected zones are quantitatively compared to those of the corresponding zones of the reference material. Following a collaborative trial involving three laboratories in three countries, the method was applied to check the quality of further candidates for establishing an appropriate reference material. In conclusion, this case demonstrates that a single HPTLC analysis can provide information about identity, purity, and minimum content of markers of an herbal drug. Georg Thieme Verlag KG Stuttgart · New York.

A new omni-directional multi-camera system for high resolution surveillance

NASA Astrophysics Data System (ADS)

Cogal, Omer; Akin, Abdulkadir; Seyid, Kerem; Popovic, Vladan; Schmid, Alexandre; Ott, Beat; Wellig, Peter; Leblebici, Yusuf

2014-05-01

Omni-directional high resolution surveillance has a wide application range in defense and security fields. Early systems used for this purpose are based on parabolic mirror or fisheye lens where distortion due to the nature of the optical elements cannot be avoided. Moreover, in such systems, the image resolution is limited to a single image sensor's image resolution. Recently, the Panoptic camera approach that mimics the eyes of flying insects using multiple imagers has been presented. This approach features a novel solution for constructing a spherically arranged wide FOV plenoptic imaging system where the omni-directional image quality is limited by low-end sensors. In this paper, an overview of current Panoptic camera designs is provided. New results for a very-high resolution visible spectrum imaging and recording system inspired from the Panoptic approach are presented. The GigaEye-1 system, with 44 single cameras and 22 FPGAs, is capable of recording omni-directional video in a 360°×100° FOV at 9.5 fps with a resolution over (17,700×4,650) pixels (82.3MP). Real-time video capturing capability is also verified at 30 fps for a resolution over (9,000×2,400) pixels (21.6MP). The next generation system with significantly higher resolution and real-time processing capacity, called GigaEye-2, is currently under development. The important capacity of GigaEye-1 opens the door to various post-processing techniques in surveillance domain such as large perimeter object tracking, very-high resolution depth map estimation and high dynamicrange imaging which are beyond standard stitching and panorama generation methods.

Comparative ultrastructural study of spermatozoa in some oyster species from the Asian-Pacific Coast.

PubMed

Yurchenko, Olga V

2012-02-01

Sperm organization in the oysters Crassostrea gigas, Crassostrea nippona, Crassostrea cf. rivularis and Saccostrea cf. mordax inhabiting Asian Pacific coast was studied. The spermatozoa of all studied species had a number of common morphological characters such as a cup-like acrosome with heterogeneous matrix on its top, an axial rod in the subacrosomal space, a barrel-shaped nucleus, four mitochondria in the midpiece, pericentriolar complexes, and a 9+2-organized flagellum. The spermatozoa of C. cf. rivularis differed from the other species by having cytoplasm processes in the midpiece region. Such structures have never been described in the Ostreidae. Additionally, each species could be identified by the shape and size of sperm compartments (acrosome, nucleus, anterior nuclear fossa). The most significant interspecific difference was found in the size of an anterior nuclear fossa. The smallest anterior nuclear fossa was found in C. cf. rivularis (about 0.24 μm in length reaching about 22% of the nuclear length) while the biggest in C. gigas from the Sea of Japan (about 0.53 μm in length reaching about 46% of the nuclear length). The spermatozoa of C. gigas collected from the Sea of Japan and Taiwan Strait differed significantly in almost all the studied parameters. Since sperm morphology has been successfully used for species differentiation, this suggests the existence of two species rather than two populations. The data obtained indicate the species-specific difference in the sperm ultrastructure within the Ostreidae, which may be identified both ultrastructurally and morphometrically. Copyright © 2011 Elsevier Ltd. All rights reserved.

Haemocytes from Crassostrea gigas and OsHV-1: A promising in vitro system to study host/virus interactions.

PubMed

Morga, Benjamin; Faury, Nicole; Guesdon, Stéphane; Chollet, Bruno; Renault, Tristan

2017-11-01

Since 2008, mass mortality outbreaks associated with the detection of particular variants of OsHV-1 have been reported in Crassostrea gigas spat and juveniles in several countries. Recent studies have reported information on viral replication during experimental infection. Viral DNA and RNA were also detected in the haemolymph and haemocytes suggesting that the virus could circulate through the circulatory system. However, it is unknown if the virus is free in the haemolymph, passively associated at the surface of haemocytes, or able to infect and replicate inside these cells inducing (or not) virion production. In the present study, we collected haemocytes from the haemolymphatic sinus of the adductor muscle of healthy C. gigas spat and exposed them in vitro to a viral suspension. Results showed that viral RNAs were detectable one hour after contact and the number of virus transcripts increased over time in association with an increase of viral DNA detection. These results suggested that the virus is able to initiate replication rapidly inside haemocytes maintained in vitro. These in vitro trials were also used to carry out a dual transcriptomic study. We analyzed concomitantly the expression of some host immune genes and 15 viral genes. Results showed an up regulation of oyster genes currently studied during OsHV-1 infection. Additionally, transmission electron microscopy examination was carried out and did not allow the detection of viral particles. Moreover, All the results suggested that the in vitro model using haemocytes can be valuable for providing new perspective on virus-oyster interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of Antifouling Biocides on Molecular and Biochemical Defense System in the Gill of the Pacific Oyster Crassostrea gigas

PubMed Central

Park, Mi Seon; Kim, Young Dae; Kim, Bo-Mi; Kim, Youn-Jung; Kim, Jang Kyun; Rhee, Jae-Sung

2016-01-01

Antifouling biocides such as organotin compounds and their alternatives are potent toxicants in marine ecosystems. In this study, we employed several molecular and biochemical response systems of the Pacific oyster Crassostrea gigas to understand a potential mode of action of antifouling biocides (i.e. tributyltin (TBT), diuron and irgarol) after exposure to different concentrations (0.01, 0.1, and 1 μg L-1) for 96 h. As a result, all the three antifouling biocides strongly induced the antioxidant defense system. TBT reduced both enzymatic activity and mRNA expression of Na+/K+-ATPase and acetylcholinesterase (AChE). Lower levels of both Na+/K+-ATPase activity and AChE mRNA expression were observed in the diuron-exposed oysters compared to the control, while the irgarol treatment reduced only the transcriptional expression of AChE gene. We also analyzed transcript profile of heat shock protein (Hsp) superfamily in same experimental conditions. All antifouling biocides tested in this study significantly modulated mRNA expression of Hsp superfamily with strong induction of Hsp70 family. Taken together, overall results indicate that representative organotin TBT and alternatives have potential hazardous effects on the gill of C. gigas within relatively short time period. Our results also suggest that analyzing a series of molecular and biochemical parameters can be a way of understanding and uncovering the mode of action of emerging antifouling biocides. In particular, it was revealed that Pacific oysters have different sensitivities depend on the antifouling biocides. PMID:28006823

Sclerochronology - a highly versatile tool for mariculture and reconstruction of life history traits of the queen conch, textit{Strombus gigas} (Gastropoda)

NASA Astrophysics Data System (ADS)

Radermacher, Pascal; Schöne, Bernd R.; Gischler, Eberhard; Oschmann, Wolfgang; Thébault, Julien; Fiebig, Jens

2010-05-01

The shell of the queen conch Strombus gigas provides a rapidly growing palaeoenvironmental proxy archive, allowing the detailed reconstruction of important life-history traits such as ontogeny, growth rate and growth seasonality. In this study, modern sclerochronological methods are used to cross-date the palaeotemperatures derived from the shell with local sea surface temperature (SST) records. The growth history of the shell suggests a bimodal seasonality in growth, with the growing season confined to the interval between April and November. In Glovers Reef, offshore Belize, the queen conch accreted shell carbonate at rates of up to 6 mm day-1 during the spring (April-June) and autumn (September-November). However a reduced period of growth occurred during the mid-summer months (July-August). The shell growth patterns indicate a positive response to annual seasonality with regards to precipitation. It seems likely that when precipitation levels are high, food availability is increased as the result of nutrient input to the ecosystem in correspondence with an increase in coastal runoff. Slow growth rates occur when precipitation, and as a consequence riverine runoff, is low. The SST however appears to influence growth only on a secondary level. Despite the bimodal growing season and the winter cessation in growth, the growth rates reconstructed here from two S. gigas shells are among the fastest yet reported for this species. The S. gigas specimens from Belize reached their final shell height (of 22.7 and 23.5 cm in distance between the apex and the siphonal notch) at the transition to adulthood in just 2 years. The extremely rapid growth as observed in this species permits detailed, high-resolution reconstructions of life-history traits where sub-daily resolutions can be achieved with ease. The potential for future studies has yet to be further explored. Queen conch sclerochronology provides an opportunity to recover extremely high-resolution palaeotemperature records, which could be used to improve numeric climate models, where the shells essentially function as mineralized buoys. The shell recorder may also help to reveal changes in biogeochemical dynamics in benthic ecosystems on intra-seasonal timescales in the fossil record. Furthermore, sclerochronology provides a rapid, effective and highly versatile investigative strategy when compared to time- and cost-consuming fieldwork for improving fisheries management and maricultural pursuits.

Analysis of Giga-size Earth Observation Data in Open Source GRASS GIS 7 - from Desktop to On-line Solutions.

NASA Astrophysics Data System (ADS)

Stepinski, T. F.; Mitasova, H.; Jasiewicz, J.; Neteler, M.; Gebbert, S.

2014-12-01

GRASS GIS is a leading open source GIS for geospatial analysis and modeling. In addition to being utilized as a desktop GIS it also serves as a processing engine for high performance geospatial computing for applications in diverse disciplines. The newly released GRASS GIS 7 supports big data analysis including temporal framework, image segmentation, watershed analysis, synchronized 2D/3D animations and many others. This presentation will focus on new GRASS GIS 7-powered tools for geoprocessing giga-size earth observation (EO) data using spatial pattern analysis. Pattern-based analysis connects to human visual perception of space as well as makes geoprocessing of giga-size EO data possible in an efficient and robust manner. GeoPAT is a collection of GRASS GIS 7 modules that fully integrates procedures for pattern representation of EO data and patterns similarity calculations with standard GIS tasks of mapping, maps overlay, segmentation, classification(Fig 1a), change detections etc. GeoPAT works very well on a desktop but it also underpins several GeoWeb applications (http://sil.uc.edu/ ) which allow users to do analysis on selected EO datasets without the need to download them. The GRASS GIS 7 temporal framework and high resolution visualizations will be illustrated using time series of giga-size, lidar-based digital elevation models representing the dynamics of North Carolina barrier islands over the past 15 years. The temporal framework supports efficient raster and vector data series analysis and simplifies data input for visual analysis of dynamic landscapes (Fig. 1b) allowing users to rapidly identify vulnerable locations, changes in built environment and eroding coastlines. Numerous improvements in GRASS GIS 7 were implemented to support terabyte size data processing for reconstruction of MODIS land surface temperature (LST) at 250m resolution using multiple regressions and PCA (Fig. 1c) . The new MODIS LST series (http://gis.cri.fmach.it/eurolst/) includes 4 maps per day since year 2000, provide improved data for the epidemiological predictions, viticulture, assessment of urban heat islands and numerous other applications. The presentation will conclude with outline of future development for big data interfaces to further enhance the web-based GRASS GIS data analysis.

Ecological periodic tables for benthic macrofaunal usage of estuarine habitats in the US Pacific Northwest

EPA Science Inventory

Estuary-wide benthic macrofauna─habitat associations were determined for 9 habitats (intertidal eelgrass [Zostera marina], dwarf eelgrass [Zostera japonica], oyster [Crassostrea gigas], mud shrimp [Upogebia pugettensis], ghost shrimp [Neotrypaea californiensis], shell, sand, mud,...

Jargon that Computes: Today's PC Terminology.

ERIC Educational Resources Information Center

Crawford, Walt

1997-01-01

Discusses PC (personal computer) and telecommunications terminology in context: Integrated Services Digital Network (ISDN); Asymmetric Digital Subscriber Line (ADSL); cable modems; satellite downloads; T1 and T3 lines; magnitudes ("giga-,""nano-"); Central Processing Unit (CPU); Random Access Memory (RAM); Universal Serial Bus…

Coordinating the 2009 RHIC Run

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brookhaven Lab - Mei Bai

2009-04-13

Physicists working at the Brookhaven National Lab's Relativistic Heavy Ion Collider (RHIC) are exploring the puzzle of proton spin as they begin taking data during the 2009 RHIC run. For the first time, RHIC is running at a record energy of 500 giga-elect

Coordinating the 2009 RHIC Run

ScienceCinema

Brookhaven Lab - Mei Bai

2017-12-09

Physicists working at the Brookhaven National Lab's Relativistic Heavy Ion Collider (RHIC) are exploring the puzzle of proton spin as they begin taking data during the 2009 RHIC run. For the first time, RHIC is running at a record energy of 500 giga-elect

Seawater acidification aggravated cadmium toxicity in the oyster Crassostrea gigas: Metal bioaccumulation, subcellular distribution and multiple physiological responses.

PubMed

Cao, Ruiwen; Liu, Yongliang; Wang, Qing; Dong, Zhijun; Yang, Dinglong; Liu, Hui; Ran, Wen; Qu, Yi; Zhao, Jianmin

2018-06-17

Mounting evidence has demonstrated the combined effects of ocean acidification (OA) and other environmental stressors on marine organisms. Although metal pollution is widely distributed in coasts and estuaries, the combined effects of OA and metal pollution have received little attention until recent years. In this study, the accumulation and subcellular distribution of cadmium (Cd) and the physiological responses of the oyster Crassostrea gigas were investigated after 31 days of exposure to OA and Cd, either alone or in combination. Increased Cd accumulation was found both in gills (about 57% increase at pH 7.8, 22% increase at pH 7.6) and digestive glands (about 38% increase at pH 7.8, 22% increase at pH 7.6) of C. gigas under elevated pCO 2 exposure. Although a similar total Cd accumulation pattern was seen in oyster gills and digestive glands, a higher partition of Cd in the BIM (biologically inactive metal) fractions of gills (about 60%) was found in Cd-exposed treatments compared to the digestive glands (about 45%), which might correspond to the generally lower toxicity in gills. Moreover, synergetic effects of Cd and OA on the oxidative stresses, histopathological damage, and apoptosis of exposed oysters were observed in this study, which might be explained by significant interactions of these two factors on increased generation of ROS. These findings demonstrated that OA could aggravate the toxicity of metals in marine organisms, with significant implications for coastal benthic ecosystems regarding the widespread metal contamination and the concurrent increase of acidified seawater. Copyright © 2018 Elsevier B.V. All rights reserved.

The B-cell translocation gene 1 (CgBTG1) identified in oyster Crassostrea gigas exhibit multiple functions in immune response.

PubMed

Liu, Rui; Cheng, Qi; Wang, Xiudan; Chen, Hao; Wang, Weilin; Zhang, Huan; Wang, Lingling; Song, Linsheng

2017-02-01

B-cell translocation gene 1 (BTG1) is a member of the anti-proliferative gene family, which plays important roles in regulation of cell cycle. In the present study, a B-cell translocation gene 1 molecule homologue (designed CgBTG1) are identified and characterized in oyster Crassostrea gigas. CgBTG1 contains a conserved BTG domain with Box A and Box B motifs, and it shares high similarities with both BTG1 and BTG2 proteins in vertebrates. CgBTG1 mRNA is predominantly expressed in hemocytes, and its expression level in hemocytes is significantly up-regulated at 6 h (5.40-fold, p < 0.01) post Vibrio splendidus stimulation. The apoptosis rate of oyster hemocytes is significantly decreased (p < 0.05) after CgBTG1 interfered by dsRNA (dsCgBTG1). This is indicated that CgBTG1 participated in the regulation of oyster hemocytes apoptosis. Furthermore, CgBTG1 could also induce the apoptosis of cancer cells (HeLa, A549 and BEL7402) in vitro. Compared with normal oysters, both vessel-like structures and muscle fibers in CgBTG1 interfered oysters are severely damaged after V. splendidus challenge in paraffin section, considering that CgBTG1 possessed an analogous feature of angiogenesis for maintenance of vessel-like structures in adductor muscle of oyster. The results suggests that CgBTG1 is a multi-functional molecule involved in the immune response of C. gigas against pathogen infection, which provides more clues for intensive studies of BTG family proteins in invertebrates. Copyright © 2016 Elsevier Ltd. All rights reserved.

D1 dopamine receptor is involved in shell formation in larvae of Pacific oyster Crassostrea gigas.

PubMed

Liu, Zhaoqun; Wang, Lingling; Yan, Yunchen; Zheng, Yan; Ge, Wenjing; Li, Meijia; Wang, Weilin; Song, Xiaorui; Song, Linsheng

2018-07-01

Dopamine (DA), a significant member of catecholamines, is reported to induce biomineralization of calcium carbonate vaterite microspheres via dopamine receptor (DR) in bivalves, implying the modulation of dopaminergic system on shell formation during larval development. In this research, a homologue of D1 type DR (CgD1DR-1) was identified from oyster Crassostrea gigas, whose full length cDNA was 1197 bp. It was widely expressed in various tissues of C. gigas, with the significantly higher levels in hepatopancreas, mantle, muscle and gill. During developmental stages, the mRNA transcripts of CgD1DR-1 in D-shape larvae were obviously higher (p < 0.05) than those in trochophore and umbo larvae, and CO 2 exposure could inhibit the synthesis of DA and mRNA expression of CgD1DR-1. After cell transfection and DA treatment, intracellular cAMP in cells with the expression of CgD1DR-1 increased significantly (p < 0.05). Furthermore, the incubation with SCH 23390 for the blockage of CgD1DR-1 significantly restrained the expressions of six shell formation-related genes including CgTyrosinase-1, CgTyrosinase-3, CgChitinaseLP, CgAMC, CgBMP and CgBMPR in trochophore and D-shape larvae. These results jointly suggested that DA together with its receptor CgD1DR-1 might be involved in shell formation during oyster larval development from trochophore to D-shape larvae, and CO 2 -induced ocean acidification (OA) might influence marine bivalves by inhibiting the DA-D1DR pathway to prohibit their shell formation. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Antimicrobial Defense of the Pacific Oyster, Crassostrea gigas. How Diversity may Compensate for Scarcity in the Regulation of Resident/Pathogenic Microflora

PubMed Central

Schmitt, Paulina; Rosa, Rafael Diego; Duperthuy, Marylise; de Lorgeril, Julien; Bachère, Evelyne; Destoumieux-Garzón, Delphine

2012-01-01

Healthy oysters are inhabited by abundant microbial communities that vary with environmental conditions and coexist with immunocompetent cells in the circulatory system. In Crassostrea gigas oysters, the antimicrobial response, which is believed to control pathogens and commensals, relies on potent oxygen-dependent reactions and on antimicrobial peptides/proteins (AMPs) produced at low concentrations by epithelial cells and/or circulating hemocytes. In non-diseased oysters, hemocytes express basal levels of defensins (Cg-Defs) and proline-rich peptides (Cg-Prps). When the bacterial load dramatically increases in oyster tissues, both AMP families are driven to sites of infection by major hemocyte movements, together with bactericidal permeability/increasing proteins (Cg-BPIs) and given forms of big defensins (Cg-BigDef), whose expression in hemocytes is induced by infection. Co-localization of AMPs at sites of infection could be determinant in limiting invasion as synergies take place between peptide families, a phenomenon which is potentiated by the considerable diversity of AMP sequences. Besides, diversity occurs at the level of oyster AMP mechanisms of action, which range from membrane lysis for Cg-BPI to inhibition of metabolic pathways for Cg-Defs. The combination of such different mechanisms of action may account for the synergistic activities observed and compensate for the low peptide concentrations in C. gigas cells and tissues. To overcome the oyster antimicrobial response, oyster pathogens have developed subtle mechanisms of resistance and evasion. Thus, some Vibrio strains pathogenic for oysters are equipped with AMP-sensing systems that trigger resistance. More generally, the known oyster pathogenic vibrios have evolved strategies to evade intracellular killing through phagocytosis and the associated oxidative burst. PMID:22783227

Ostreid herpesvirus 1 infection among Pacific oyster (Crassostrea gigas) Spat: relevance of water temperature to virus replication and circulation prior to the onset of mortality.

PubMed

Renault, Tristan; Bouquet, Anne Lise; Maurice, Julien-Thomas; Lupo, Coralie; Blachier, Philippe

2014-09-01

A number of bivalve species worldwide, including the Pacific oyster, Crassostrea gigas, have been affected by mass mortality events associated with herpesviruses, resulting in significant losses. A particular herpesvirus was purified from naturally infected larval Pacific oysters, and its genome was completely sequenced. This virus has been classified as Ostreid herpesvirus 1 (OsHV-1) within the family Malacoherpesviridae. Since 2008, mass mortality outbreaks among C. gigas in Europe have been related to the detection of a variant of OsHV-1 called μVar. Additional data are necessary to better describe mortality events in relation to environmental-parameter fluctuations and OsHV-1 detection. For this purpose, a single batch of Pacific oyster spat was deployed in 4 different locations in the Marennes-Oleron area (France): an oyster pond ("claire"), a shellfish nursery, and two locations in the field. Mortality rates were recorded based on regular observation, and samples were collected to search for and quantify OsHV-1 DNA by real-time PCR. Although similar massive mortality rates were reported at the 4 sites, mortality was detected earlier in the pond and in the nursery than at both field sites. This difference may be related to earlier increases in water temperature. Mass mortality was observed among oysters a few days after increases in the number of PCR-positive oysters and viral-DNA amounts were recorded. An initial increment in the number of PCR-positive oysters was reported at both field sites during the survey in the absence of significant mortality. During this period, the water temperature was below 16°C. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Ostreid Herpesvirus 1 Infection among Pacific Oyster (Crassostrea gigas) Spat: Relevance of Water Temperature to Virus Replication and Circulation Prior to the Onset of Mortality

PubMed Central

Bouquet, Anne Lise; Maurice, Julien-Thomas; Lupo, Coralie; Blachier, Philippe

2014-01-01

A number of bivalve species worldwide, including the Pacific oyster, Crassostrea gigas, have been affected by mass mortality events associated with herpesviruses, resulting in significant losses. A particular herpesvirus was purified from naturally infected larval Pacific oysters, and its genome was completely sequenced. This virus has been classified as Ostreid herpesvirus 1 (OsHV-1) within the family Malacoherpesviridae. Since 2008, mass mortality outbreaks among C. gigas in Europe have been related to the detection of a variant of OsHV-1 called μVar. Additional data are necessary to better describe mortality events in relation to environmental-parameter fluctuations and OsHV-1 detection. For this purpose, a single batch of Pacific oyster spat was deployed in 4 different locations in the Marennes-Oleron area (France): an oyster pond (“claire”), a shellfish nursery, and two locations in the field. Mortality rates were recorded based on regular observation, and samples were collected to search for and quantify OsHV-1 DNA by real-time PCR. Although similar massive mortality rates were reported at the 4 sites, mortality was detected earlier in the pond and in the nursery than at both field sites. This difference may be related to earlier increases in water temperature. Mass mortality was observed among oysters a few days after increases in the number of PCR-positive oysters and viral-DNA amounts were recorded. An initial increment in the number of PCR-positive oysters was reported at both field sites during the survey in the absence of significant mortality. During this period, the water temperature was below 16°C. PMID:24973071

A biomineralization study of the Indo-Pacific giant clam Tridacna gigas

NASA Astrophysics Data System (ADS)

Gannon, M. E.; Pérez-Huerta, A.; Aharon, P.; Street, S. C.

2017-06-01

The giant clam, Tridacna gigas, is an important faunal component of reef ecosystems of the Indo-Pacific region. In addition to its ecological role, shells of this bivalve species are useful bioarchives for past climate and environmental reconstructions. However, the biomineralization processes involved in shell aragonite deposition are insufficiently understood. Here, we present a study of the shell microstructure of modern specimens from Palm Island, Great Barrier Reef (GBR), Australia, and Huon Peninsula, Papua New Guinea (PNG), using a combination of petrography, scanning electron microscopy, electron backscatter diffraction, Raman spectroscopy and stable carbon isotope ratios. Daily growth increments were recognizable in all specimens through ontogeny, and counting these growth lines provides a robust specimen age estimate. For the internal layers, paired increments of organized aragonitic needles and compact, oblong crystals were recognized in a specimen from PNG, whereas specimens from GBR were composed of shield-like crystals that were not definable at the microscale. The combination of nutrient availability, rainfall and solar irradiance are likely to be the most significant factors controlling shell growth and may explain the observed differences in microstructure. The external layer, identical in all specimens, was composed of dendritic microstructure that is significantly enriched in 13C compared to the internal layer, suggesting different metabolic controls on layer deposition. We propose that the mineralization of the internal and external layers is independent from each other and associated with the activity of specific mantles. Future studies using T. gigas shells as bioarchives should consider the microstructure as it reflects the environment in which the individual lived and the differences in mineralization pathways of internal and external layers.

Utilising caging techniques to investigate metal assimilation in Nucella lapillus, Mytilus edulis and Crassostrea gigas at three Irish coastal locations

NASA Astrophysics Data System (ADS)

Giltrap, Michelle; Macken, Ailbhe; Davoren, Maria; McGovern, Evin; Foley, Barry; Larsen, Martin; White, Jonathan; McHugh, Brendan

2013-11-01

Pollution by metals has been of increasing concern for a number of decades but at present, the mechanism of metal accumulation in sentinel species is not fully understood and further studies are required for environmental risk assessment of metals in aquatic environments. The use of caging techniques has proven to be useful for assessment of water quality in coastal and estuarine environments. This study investigates the application of caging techniques for monitoring uptake of 20 elements [Li, Na, Mg, Al, P, K, Ca, V, Cr, Mn, Fe, Ni, Co, Cu, As, Sb, Pb, Hg, Cd and Zn] in three marine species namely Nucella lapillus, Mytilus edulis and Crassostrea gigas. Stable isotopes were used to determine predatory effects and also used for modelling metal uptake in test species and to track nutrient assimilation. Metal levels were monitored at three different coastal locations, namely Dublin Bay, Dunmore East and Omey Island over 18 weeks. Significant differences in concentrations of Mn, Co and Zn between mussels and oysters were found. Correlations between cadmium levels in N. lapillus and δ13C and δ15N suggest dietary influences in Cd uptake. Levels of Zn were highest in C. gigas compared to the other two species and levels of Zn were most elevated at the Dunmore East site. Copper levels were more elevated in all test species at both Dublin Bay and Dunmore East. Mercury was raised in all species at Dunmore East compared to the other two sites. Biotic accumulation of metals in the test species demonstrates that caging techniques can provide a valid tool for biomonitoring in metal impacted areas.

Patients with metastatic breast cancer leading to CD4+ T cell lymphopaenia have poor outcome.

PubMed

Trédan, Olivier; Manuel, Manuarii; Clapisson, Gilles; Bachelot, Thomas; Chabaud, Sylvie; Bardin-dit-Courageot, Christine; Rigal, Chantal; Biota, Cathy; Bajard, Agathe; Pasqual, Nicolas; Blay, Jean-Yves; Caux, Christophe; Ménétrier-Caux, Christine

2013-05-01

Low lymphocyte count is a prognostic factor in cancer patients including metastatic breast cancer patients (MBC) but the relative role of each lymphocyte subtype is unclear in MBC. The impact of lymphocyte subsets was analysed in two prospective MBC patients' cohorts. Cohort A patients (n=103) were included before the first line of chemotherapy and cohort B patients (n=101) were included after at least one line of chemotherapy. Extensive phenotypic analyses were performed on fresh whole blood. Plasma cytokines levels were measured using commercially available Luminex-based multiplex kits. Prognostic value of lymphocyte subsets and circulating cytokines was analysed. In both cohorts, severe lymphopaenia (<0.7 Giga/L) correlated with poor overall survival (OS) (median OS: 6.6 months versus 21.7 months in cohort A and 4.5 versus 9 months in cohort B). CD8(+), CD19(+) and CD56(+) T cell counts had no significant prognostic value for OS. After stratification (≤0.2, [0.20-0.45], >0.45 Giga/L), CD4 lymphopaenia appeared to be correlated with poor OS in both cohorts. Furthermore, severe CD4(+) lymphopaenia (≤0.2 Giga/L) was strongly correlated with poor OS in both cohorts (1.2 months versus 24.9 months in cohort A and 5.7 versus 13.1 months in cohort B). In multivariate analysis, after stratification CD4(+) lymphopaenia appeared to be an independent prognostic factor for OS in both cohorts. CD4(+) lymphopaenia correlated with low plasmatic levels of CCL22 that might directly contribute to CD4(+) lymphopaenia. CD4(+) lymphopaenia was associated with reduced OS in MBC patients regardless of the chemotherapy line. Decreased levels of plasmatic CCL22 may contribute to CD4(+) lymphopaenia. Copyright © 2012 Elsevier Ltd. All rights reserved.

Molecular cloning and functional analysis of tumor necrosis factor receptor-associated factor 6 (TRAF6) in Crossastrea gigas.

PubMed

Mao, Fan; Li, Jun; Zhang, Yuehuan; Xiang, Zhiming; Zhang, Yang; Yu, Ziniu

2017-09-01

Tumor necrosis factor receptor-associated factor 6 (TRAF6) has been demonstrated to be a key signaling molecule involved in adaptive and innate immunity. In this study, we obtained the full length CgTRAF6 cDNA and analyzed the characteristics of the ORF and the peptide sequence in Crassostrea gigas. The deduced protein sequence of CgTRAF6 includes a conserved C-terminal TRAF domain following the RING and the zinc finger domain. The TRAF domain is composed of coiled-coil TRAF-N and MATH (meprin and TRAF-C homology) subdomains. Furthermore, phylogenetic analysis revealed that CgTRAF6 is clustered together with other members TRAF6 family and is placed in a sub-cluster singly which had a close relationship with Drosophila melanogaster. Expression analysis of CgTRAF6 indicated its constitutive expression in all tissues including mantle, adductor muscle, digestive tract, gonads, heart, gill, and hemocyte. Immune challenge with Vibrio alginolyticus and poly I:C resulted in significant up-regulation of CgTRAF6 expression. Dual-luciferase reporter assays showed that CgTRAF6 could activate both pNF-κB-Luc and pISRE-Luc expression, suggesting CgTRAF6 is potentially involved in NF-κB and the interferon signaling pathway. Furthermore, RNAi mediated knockdown of CgTRAF6 resulted in the down-regulation of several putative anti-viral signaling (IRF) and effector (PKR & Viperin) molecules coding genes, 7 days post-injection. These results collectively indicate that CgTRAF6 is a member of TRAF6 sub-family and is potentially involved in immune defense system against invading bacteria and viruses in Crassostrea gigas. Copyright © 2017 Elsevier Ltd. All rights reserved.

The cytochemical and ultrastructural characteristics of phagocytes in the Pacific oyster Crassostrea gigas.

PubMed

Jiang, Shuai; Jia, Zhihao; Xin, Lusheng; Sun, Ying; Zhang, Ran; Wang, Weilin; Wang, Lingling; Song, Linsheng

2016-08-01

Phagocytes have been proved to play vital roles in the innate immune response. However, the cellular characteristics of phagocytes in invertebrates, especially in molluscs, remain largely unknown. In the present study, fluorescence activated cell sorting (FACS) was employed to sort the phagocytes from the non-phagocytic haemocytes of the Pacific oyster Crassostrea gigas. The cytochemical staining analysis revealed that phagocytes were positive staining for α-naphthyl acetate esterase and myeloperoxidase, while negative staining for toluidine blue and periodic acid-Schiff. The non-phagocytic haemocytes exhibited positive staining for periodic acid-Schiff, weak positive staining for toluidine blue, but negative staining for α-naphthyl acetate esterase and myeloperoxidase. In addition, phagocytes exhibited ultrastructural cellular features similar to those of macrophages, with large cell diameter, rough cell membrane and extended pseudopodia revealed by the scanning electron microscopy, while the non-phagocytic haemocytes exhibited small cell diameter, smooth cell surface and round spherical shape. Transmission electron microscopy further demonstrated that phagocytes were abundant of cytoplasmic bodies and mitochondria, while non-phagocytic haemocytes were characterized as the comparatively large cell nucleus with contorted and condensed heterochromatin adherent to the nuclear envelope. Moreover, compared with non-phagocytic haemocytes, phagocytes exhibited significantly higher levels of intracellular cytokines, including tumor necrosis factor, interferon-like protein and interleukin-17, and significantly higher abundance of lysosome and reactive oxygen species, which were of great importance to the activation of immune response and pathogen clearance. Taken together, these findings revealed the different cytochemical and ultrastructural features between phagocytes and non-phagocytic haemocytes in C. gigas, which would provide an important clue to investigate the mechanism of phagocytosis underlying the innate immune response. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transcriptomic and Quantitative Proteomic Analyses Provide Insights Into the Phagocytic Killing of Hemocytes in the Oyster Crassostrea gigas

PubMed Central

Jiang, Shuai; Qiu, Limei; Wang, Lingling; Jia, Zhihao; Lv, Zhao; Wang, Mengqiang; Liu, Conghui; Xu, Jiachao; Song, Linsheng

2018-01-01

As invertebrates lack an adaptive immune system, they depend to a large extent on their innate immune system to recognize and clear invading pathogens. Although phagocytes play pivotal roles in invertebrate innate immunity, the molecular mechanisms underlying this killing remain unclear. Cells of this type from the Pacific oyster Crassostrea gigas were classified efficiently in this study via fluorescence-activated cell sorting (FACS) based on their phagocytosis of FITC-labeled latex beads. Transcriptomic and quantitative proteomic analyses revealed a series of differentially expressed genes (DEGs) and proteins present in phagocytes; of the 352 significantly high expressed proteins identified here within the phagocyte proteome, 262 corresponding genes were similarly high expressed in the transcriptome, while 140 of 205 significantly low expressed proteins within the proteome were transcriptionally low expressed. A pathway crosstalk network analysis of these significantly high expressed proteins revealed that phagocytes were highly activated in a number of antimicrobial-related biological processes, including oxidation–reduction and lysosomal proteolysis processes. A number of DEGs, including oxidase, lysosomal protease, and immune receptors, were also validated in this study using quantitative PCR, while seven lysosomal cysteine proteases, referred to as cathepsin Ls, were significantly high expressed in phagocytes. Results show that the expression level of cathepsin L protein in phagocytes [mean fluorescence intensity (MFI): 327 ± 51] was significantly higher (p < 0.01) than that in non-phagocytic hemocytes (MFI: 83 ± 26), while the cathepsin L protein was colocalized with the phagocytosed Vibrio splendidus in oyster hemocytes during this process. The results of this study collectively suggest that oyster phagocytes possess both potent oxidative killing and microbial disintegration capacities; these findings provide important insights into hemocyte phagocytic killing as a component of C. gigas innate immunity. PMID:29942306

Physical and chemical characterization of residual oil-fired power plant emissions

EPA Science Inventory

Although the toxicity of oil combustion emissions is a significant public health concern, few studies characterize the emissions from plant-scale utility boilers firing residual oil. This study remedies that deficiency by sampling and monitoring stack emissions from a 432 Giga Jo...

Exposing the dark sector with future Z factories

NASA Astrophysics Data System (ADS)

Liu, Jia; Wang, Lian-Tao; Wang, Xiao-Ping; Xue, Wei

2018-05-01

We investigate the prospects of searching dark sector models via exotic Z -boson decay at future e+e- colliders with Giga Z and Tera Z options. Four general categories of dark sector models, Higgs portal dark matter, vector-portal dark matter, inelastic dark matter, and axionlike particles, are considered. Focusing on channels motivated by the dark sector models, we carry out a model-independent study of the sensitivities of Z factories in probing exotic decays. The limits on branching ratios of the exotic Z decay are typically O (10-6- 10-8.5) for the Giga Z and O (10-7.5- 10-11) for the Tera Z , and they are compared with the projection for the high luminosity LHC. We demonstrate that future Z factories can provide its unique and leading sensitivity and highlight the complementarity with other experiments, including the indirect and direct dark matter search limits and the existing collider limits. Future Z factories will play a leading role in uncovering the hidden sector of the Universe in the future.

GIGAS: A set of microwave sensor arrays to detect molecular bremsstrahlung radiation from extensive air shower

NASA Astrophysics Data System (ADS)

Gaïor, R.; Al Samarai, I.; Berat, C.; Blanco Otano, M.; David, J.; Deligny, O.; Lebbolo, H.; Lecoz, S.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Mariş, I. C.; Montanet, F.; Repain, P.; Salamida, F.; Settimo, M.; Stassi, P.; Stutz, A.

2018-04-01

We present the GIGAS (Gigahertz Identification of Giant Air Shower) microwave radio sensor arrays of the EASIER project (Extensive Air Shower Identification with Electron Radiometers), deployed at the site of the Pierre Auger cosmic ray observatory. The aim of these novel arrays is to probe the intensity of the molecular bremsstrahlung radiation expected from the development of the extensive air showers produced by the interaction of ultra high energy cosmic rays in the atmosphere. In the designed setup, the sensors are embedded within the surface detector array of the Pierre Auger observatory allowing us to use the particle signals at ground level to trigger the radio system. A series of seven, then 61 sensors have been deployed in the C-band, followed by a new series of 14 higher sensitivity ones in the C-band and the L-band. The design, the operation, the calibration and the sensitivity to extensive air showers of these arrays are described in this paper.

Effects of Organoboron Antifoulants on Oyster and Sea Urchin Embryo Development

PubMed Central

Tsunemasa, Noritaka; Tsuboi, Ai; Okamura, Hideo

2013-01-01

Prohibition of Ot (organotin) compounds was introduced in Japan in 1997 and worldwide from September 2008. This meant that the production of paints containing TBT compounds was stopped and alternatives to the available Ot antifoulants had to be developed. It has been claimed that the degradation by-products of these alternative antifoulants were less toxic than those of Ot compounds. Since the introduction of the alternative antifoulants, the accumulation of these compounds has been reported in many countries. However, the toxicity of these compounds was still largely unreported. In this research, the toxicity of the alternative Ot antifoulants TPBP (triphenylborane pyridine) and TPBOA (triphenylborane octadecylamine) and their degradation products on Crassostea gigas and Hemicentrotus pulcherrimus were tested. The results showed that toxic effects in Crassostea gigas was higher for each antifouling biocide than that in Hemicentrotus pulcherrimus. Also, while the toxicity of the Organoboron antifoulants and the Ots were the same, the former’s degradation products were much less harmful. PMID:23263671

Development of an in situ hybridization assay for the detection of ostreid herpesvirus type 1 mRNAs in the Pacific oyster, Crassostrea gigas.

PubMed

Corbeil, Serge; Faury, Nicole; Segarra, Amélie; Renault, Tristan

2015-01-01

An in situ hybridization protocol for detecting mRNAs of ostreid herpesvirus type 1 (OsHV-1) which infects Pacific oysters, Crassostrea gigas, was developed. Three RNA probes were synthesized by cloning three partial OsHV-1 genes into plasmids using three specific primer pairs, and performing a transcription in the presence of digoxigenin dUTP. The RNA probes were able to detect the virus mRNAs in paraffin sections of experimentally infected oysters 26 h post-injection. The in situ hybridization showed that the OsHV-1 mRNAs were mainly present in connective tissues in gills, mantle, adductor muscle, digestive gland and gonads. DNA detection by in situ hybridization using a DNA probe and viral DNA quantitation by real-time PCR were also performed and results were compared with those obtained using RNA probes. Copyright © 2014 Elsevier B.V. All rights reserved.

A 1-year investigation of the parasite Haplosporidium nelsoni (MSX) in the Pacific oyster Crassostrea gigas from Dayaowan Bay, China.

PubMed

Wang, Zhongwei; Lu, Xin; Liang, Yubo

2010-06-01

The infection prevalence of the protozoan parasite Haplosporidium nelsoni (MSX) in Pacific oysters (Crassostrea gigas), collected from Dayaowan Bay on the north coast of the Yellow Sea, China, was investigated in 2007. The traditional histological method of diagnosing H. nelsoni infection in oysters was compared to that of polymerase chain reaction (PCR). Histology and the first PCR analysis detected infection in 21 (a total of 240 oysters) (8.75%) oysters, and the second PCR revealed infection in 26 oysters (10.83%). Only local or epithelial infections were found; no systemic infections were detected. Infection by H. nelsoni mostly occurred from April through October, and the monthly prevalence ranged from 5% to 25%, with a peak in August. These results suggest that the prevalence of the parasite is low in Dayaowan Bay. The prevalence of H. nelsoni is thought to be controlled in some way by temperature and salinity.

Microplastics in bivalves cultured for human consumption.

PubMed

Van Cauwenberghe, Lisbeth; Janssen, Colin R

2014-10-01

Microplastics are present throughout the marine environment and ingestion of these plastic particles (<1 mm) has been demonstrated in a laboratory setting for a wide array of marine organisms. Here, we investigate the presence of microplastics in two species of commercially grown bivalves: Mytilus edulis and Crassostrea gigas. Microplastics were recovered from the soft tissues of both species. At time of human consumption, M. edulis contains on average 0.36 ± 0.07 particles g(-1) (wet weight), while a plastic load of 0.47 ± 0.16 particles g(-1) ww was detected in C. gigas. As a result, the annual dietary exposure for European shellfish consumers can amount to 11,000 microplastics per year. The presence of marine microplastics in seafood could pose a threat to food safety, however, due to the complexity of estimating microplastic toxicity, estimations of the potential risks for human health posed by microplastics in food stuffs is not (yet) possible. Copyright © 2014 Elsevier Ltd. All rights reserved.

An evaluation of the efficacy of using environmental DNA (eDNA) to detect giant gartersnakes (Thamnophis gigas)

USGS Publications Warehouse

Halstead, Brian J.; Wood, Dustin A.; Bowen, Lizabeth; Waters, Shannon C.; Vandergast, Amy G.; Ersan, Julia S.; Skalos, Shannon M.; Casazza, Michael L.

2017-09-28

Detecting populations of rare or cryptic species is essential for their conservation. For species like giant gartersnakes (Thamnophis gigas), conventional survey methods can be expensive and inefficient. These sampling difficulties might be overcome by modern techniques that detect deoxyribonucleic acid (DNA) shed by organisms into the environment (eDNA). We evaluated the efficacy of detecting giant gartersnake eDNA in water samples from the laboratory and at locations with known giant gartersnake populations in the Sacramento Valley of California, and failed to detect giant gartersnake DNA in most laboratory and all field samples. Aspects of giant gartersnake biology—such as highly keratinized skin and spending extensive time in the terrestrial environment, as well as hot, sunny, and turbid conditions in wetlands and canals of the Sacramento Valley—likely contributed to low detection probabilities. Although detection of eDNA shows promise under many conditions, further development is needed before sampling for eDNA is a viable option for detecting giant gartersnake populations.

Large-scale time-lapse microscopy of Oct4 expression in human embryonic stem cell colonies.

PubMed

Bhadriraju, Kiran; Halter, Michael; Amelot, Julien; Bajcsy, Peter; Chalfoun, Joe; Vandecreme, Antoine; Mallon, Barbara S; Park, Kye-Yoon; Sista, Subhash; Elliott, John T; Plant, Anne L

2016-07-01

Identification and quantification of the characteristics of stem cell preparations is critical for understanding stem cell biology and for the development and manufacturing of stem cell based therapies. We have developed image analysis and visualization software that allows effective use of time-lapse microscopy to provide spatial and dynamic information from large numbers of human embryonic stem cell colonies. To achieve statistically relevant sampling, we examined >680 colonies from 3 different preparations of cells over 5days each, generating a total experimental dataset of 0.9 terabyte (TB). The 0.5 Giga-pixel images at each time point were represented by multi-resolution pyramids and visualized using the Deep Zoom Javascript library extended to support viewing Giga-pixel images over time and extracting data on individual colonies. We present a methodology that enables quantification of variations in nominally-identical preparations and between colonies, correlation of colony characteristics with Oct4 expression, and identification of rare events. Copyright © 2016. Published by Elsevier B.V.

High-sensitivity NMR beyond 200,000 atmospheres of pressure

NASA Astrophysics Data System (ADS)

Meier, T.; Reichardt, S.; Haase, J.

2015-08-01

Pressure-induced changes in the chemical or electronic structure of solids require pressures well into the Giga-Pascal (GPa) range due to the strong bonding. Anvil cell designs can reach such pressures, but their small and mostly inaccessible sample chamber has severely hampered NMR experiments in the past. With a new cell design that has a radio frequency (RF) micro-coil in the high pressure chamber, NMR experiments beyond 20 Giga-Pascal are reported for the first time. 1 H NMR of water shows sensitivity and resolution obtained with the cells, and 63 Cu NMR on a cuprate superconductor (YBa2Cu3O7-δ) demonstrates that single-crystals can be investigated, as well. 115 In NMR of the ternary chalcogenide AgInTe2 discovers an insulator-metal transition with shift and relaxation measurements. The pressure cells can be mounted easily on standard NMR probes that fit commercial wide-bore magnets with regular cryostats for field- and temperature-dependent measurements ready for many applications in physics and chemistry.

Hematology and plasma biochemistry values for the giant garter snake (Thamnophis gigas) and valley garter snake (Thamnophis sirtalis fitchi) in the Central Valley of California.

PubMed

Wack, Raymund F; Hansen, Eric; Small, Marilyn; Poppenga, Robert; Bunn, David; Johnson, Christine K

2012-04-01

Hematology and plasma biochemistry parameters are useful in the assessment and management of threatened and endangered species. Although reference ranges are readily available for many mammalian species, reference ranges for snakes are lacking for most species. We determined hematology and plasma biochemistry reference ranges for giant garter snakes (Thamnophis gigas) and valley garter snakes (Thamnophis sirtalis fitchi) living in four management areas in the Central Valley of California. White blood cell, heterophil, lymphocyte, and azurophil counts in giant garter snakes were approximately twice the values of valley garter snakes. Statistically significant differences in aspartate aminotransferase, globulin, and potassium between the two species did not appear clinically significant. No significant differences were found in the measured parameters between male and female giant garter snakes. Some differences were found among collection sites. These reference ranges provide baseline data for comparisons over time and between collection sites.

Zooming in on Science

ERIC Educational Resources Information Center

Thorn, Courtney; Rye, James; Walls, Holly

2017-01-01

Photography is a creative art that continues to advance through technological innovations. Smart phones have made photography a nearly daily occurance, and people have become quite accustomed to zooming in and taking photos. This article explains how elementary teachers can harness a much "bigger" technology application--GigaPan--to help…

ABCB1 and ABCC1-like transporters in immune system cells from sea urchins Echinometra lucunter and Echinus esculentus and oysters Crassostrea gasar and Crassostrea gigas.

PubMed

Marques-Santos, Luis Fernando; Hégaret, Hélène; Lima-Santos, Leonardo; Queiroga, Fernando Ramos; da Silva, Patricia Mirella

2017-11-01

ABC transporters activity and expression have been associated with the multixenobiotic resistance phenotype (MXR). The activity of these proteins leads to a reduction in the intracellular concentration of several xenobiotics, thus reducing their toxicity. However, little attention has been given to the expression of ABC transporters in marine invertebrates and few studies have investigated their role in immune system cells of sea urchins and shellfish bivalves. The aim of the present study was to investigate the activity of the ABC transporters ABCB1 and ABCC1 in immune system cells of sea urchins (coelomocytes) and oysters (hemocytes) from different climatic regions (Brazil and France). Sea urchins and oysters were collected at Paraíba coast; Brazil (Echinometra lucunter and Crassostrea gasar) and Rade of Brest; France (Echinus esculentus and Crassostrea gigas). Coelomocytes and hemocytes were stained with the ABC transporter substrate calcein-AM and dye accumulation analyzed under flow cytometry. Reversin 205 (ABCB1 transporter blocker) and MK571 (ABCC1 transporter blocker) were used as pharmacological tools to investigate ABC transporter activity. A different pattern of calcein accumulation was observed in coelomocytes: phagocytes > colorless spherulocytes > vibrate cells > red spherulocytes. The treatment with MK571 increased calcein fluorescence levels in coelomocytes from both species. However, reversin 205 treatment was not able to increase calcein fluorescence in E. esculentus coelomocytes. These data suggest that ABCC1-like transporter activity is present in both sea urchin species, but ABCB1-like transporter activity might only be present in E. lucunter coelomocytes. The activity of ABCC1-like transporter was observed in all cell types from both bivalve species. However, reversin 205 only increased calcein accumulation in hyalinocytes of the oyster C. gasar, suggesting the absence of ABCB1-like transporter activity in all other cell types, including hyalinocytes from the oyster C. gigas. Additionally, our results showed that C. gigas exhibited higher activity of ABCC1-like transporter in all hemocyte types than C. gasar. The present work is the first to characterize ABCB1 and ABCC1-like transporter activity in the immune system cells of sea urchins E. lucunter and E. esculentus and oysters. Our findings encourage the performing studies regarding ABC transporters activity/expression in immune system cells form marine invertebrates under stress conditions and the possible use of ABC transporters as biomarkers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Non-additive effects of ocean acidification in combination with warming on the larval proteome of the Pacific oyster, Crassostrea gigas.

PubMed

Harney, Ewan; Artigaud, Sébastien; Le Souchu, Pierrick; Miner, Philippe; Corporeau, Charlotte; Essid, Hafida; Pichereau, Vianney; Nunes, Flavia L D

2016-03-01

Increasing atmospheric carbon dioxide results in ocean acidification and warming, significantly impacting marine invertebrate larvae development. We investigated how ocean acidification in combination with warming affected D-veliger larvae of the Pacific oyster Crassostrea gigas. Larvae were reared for 40h under either control (pH8.1, 20 °C), acidified (pH7.9, 20 °C), warm (pH8.1, 22 °C) or warm acidified (pH7.9, 22 °C) conditions. Larvae in acidified conditions were significantly smaller than in the control, but warm acidified conditions mitigated negative effects on size, and increased calcification. A proteomic approach employing two-dimensional electrophoresis (2-DE) was used to quantify proteins and relate their abundance to phenotypic traits. In total 12 differentially abundant spots were identified by nano-liquid chromatography-tandem mass spectrometry. These proteins had roles in metabolism, intra- and extra-cellular matrix formations, stress response, and as molecular chaperones. Seven spots responded to reduced pH, four to increased temperature, and six to acidification and warming. Reduced abundance of proteins such as ATP synthase and GAPDH, and increased abundance of superoxide dismutase, occurred when both pH and temperature changes were imposed, suggesting altered metabolism and enhanced oxidative stress. These results identify key proteins that may be involved in the acclimation of C. gigas larvae to ocean acidification and warming. Increasing atmospheric CO2 raises sea surface temperatures and results in ocean acidification, two climatic variables known to impact marine organisms. Larvae of calcifying species may be particularly at risk to such changing environmental conditions. The Pacific oyster Crassostrea gigas is ecologically and commercially important, and understanding its ability to acclimate to climate change will help to predict how aquaculture of this species is likely to be impacted. Modest, yet realistic changes in pH and/or temperature may be more informative of how populations will respond to contemporary climate change. We showed that concurrent acidification and warming mitigates the negative effects of pH alone on size of larvae, but proteomic analysis reveals altered patterns of metabolism and an increase in oxidative stress suggesting non-additive effects of the interaction between pH and temperature on protein abundance. Thus, even small changes in climate may influence development, with potential consequences later in life. Copyright © 2015 Elsevier B.V. All rights reserved.

Mortalities of eastern and pacific oyster larvae caused by the pathogens Vibrio coralliilyticus and Vibrio tubiashii

USDA-ARS?s Scientific Manuscript database

Vibrio tubiashii is reported to be a bacterial pathogen of larval Eastern oysters (Crassostrea virginica) and Pacific oysters (Crassostrea gigas) and has been associated with major hatchery crashes, causing shortages in seed oysters for commercial shellfish producers. Another bacterium, Vibrio cora...

Nonplanar linearly tapered slot antenna with balanced microstrip feed

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Lee, Richard Q.; Perl, Thomas D.

1992-01-01

A nonplanar linearly tapered slot antenna (LTSA) has been fabricated and tested at frequencies from 8 to 32 giga-Hz. The LTSA is excited by a broadband balanced microstrip transformer. The measured results include the input term return loss as well as the radiation pattern of the antenna.

(2289) Proposal to conserve the name Morchella semilibera against Phallus crassipes, P. gigas and P. undosus (Ascomycota)

USDA-ARS?s Scientific Manuscript database

True morels (Morchella) are among the most highly prized and easily recognized edible mushrooms collected during spring throughout the Northern Hemisphere. To help ensure that commercial harvests are sustainable and species diversity is preserved, management practices and conservation policies need...

COMPARISON OF CARBON AND NITROGEN FLUXES IN TIDEFLAT FOOD WEBS DOMINATED BY BURROWING SHRIMP OR BY CULTURED OYSTERS

EPA Science Inventory

Two species of indigenous, thalassinid burrowing shrimps are pests to the benthic culture of Pacific oysters (Crassostrea gigas) because deposition of sediment excavated by the shrimps buries or smothers the oysters. Carbaryl pesticide is used to reduce burrowing shrimp densitie...

Ising kinetics with hundred Giga-sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stauffer, D.; Knecht, R.

1996-12-01

From presumed world-record simulations up to 4800{sup 3} and 112{sup 5} and from the Ito algorithm applied to smaller 3D lattices we obtain the dynamical critical exponent z near 2.05 in three dimensions and J/{kappa}{sub B}T{sub c} = 0.11391 in five.

When Laws Solve Problems That Do Not Exist: Transgender Rights in the Nation's Schools

ERIC Educational Resources Information Center

Corbat, Josh

2017-01-01

Time and again research has shown that schools in which students feel safe and included promote academic achievement and overall student health (see, for example, Greytak, Kosciw, Villenas, & Giga, 2016; Michael, Merlo, Basch, Wentzel, & Wechsler, 2015). Parent networks, community organizations, and school boards nationwide continuously…

Description and key to the fifth-instars of some Cicadas (Hemiptera: Cicadidae) associated with coffee plants in Brazil.

PubMed

Maccagnan, D H B; Martinelli, N M

2011-01-01

Fifth-instars of the cicada species Dorisiana drewseni (Stål), Dorisiana viridis (Olivier), Fidicina mannifera (Fabricius), Fidicinoides pronoe (Walker) and Carineta fasciculata (Germar) are described and illustrated. Moreover, a key to the nymphs of these species along with Quesada gigas (Olivier) is also provided.

Global Ocean Forecast System (GOFS) Version 2.6. User’s Manual

DTIC Science & Technology

2010-03-31

odimens.D, which takes the rivers.dat flow levels, inputs an SST and sea surface salinity (SSS) climatology from GDEM , and outputs the orivs_1.D...Center for Medium-range Weather Forecast GB GigaByte GDEM Global Digital Elevation Map GOFS Global Ocean Forecast System HPCMP High Performance

Historical biogeography of longhorn cactus beetles: the influence of Pleistocene climate changes on American desert communities

Treesearch

Christopher Irwin Smith; Brian Dorsey Farrell

2005-01-01

Mitochondrial sequence data from three species of flightless cactus beetles, Moneilema gigas, M. armatum, and M. appressum, were analyzed. The coalescent models implemented in the program FLUCTUATE were used to test the hypothesis that these species experienced range changes following the end of the last glacial...

Merit: Who, What, and Why.

ERIC Educational Resources Information Center

Aupperle, Eric M.

1998-01-01

Looks back at the innovations/tribulations that went into the making of Merit Network, Inc., Michigan's pioneering Internet provider. Today, Merit is serving as the GigaPoP organization for its two current Internet2 members, Michigan State University and University of Michigan, and will provision a vBNS connection for Wayne State University.…

Bioinformatic mining of EST-SSR loci in the Pacific oyster, Crassostrea gigas.

PubMed

Wang, Y; Ren, R; Yu, Z

2008-06-01

A set of expressed sequence tag-simple sequence repeat (EST-SSR) markers of the Pacific oyster, Crassostrea gigas, was developed through bioinformatic mining of the GenBank public database. As of June 30, 2007, a total of 5132 EST sequences from GenBank were downloaded and screened for di-, tri- and tetra-nucleotide repeats, with criteria set at a minimum of 5, 4 and 4 repeats for the three categories of SSRs respectively. Seventeen polymorphic microsatellite markers were characterized. Allele numbers ranged from 3 to 10, and the observed and expected heterozygosity values varied from 0.125 to 0.770 and from 0.113 to 0.732 respectively. Eleven loci were at Hardy-Weinberg equilibrium (HWE); the other six loci showed significant departure from HWE (P < 0.01), suggesting possible presence of null alleles. Pairwise check of linkage disequilibrium (LD) indicated that 11 of 136 pairs of loci showed significant LD (P < 0.01), likely due to HWE present in single markers. Cross-species amplification was examined for five other Crassostrea species and reasonable results were obtained, promising usefulness of these markers in oyster genetics.

Histological Alterations in Pacific Oysters Crassostrea gigas that Survived a Summer Mortality Event in Baja California, Mexico.

PubMed

Cáceres-Martínez, Jorge; Vásquez-Yeomans, Rebeca; Danigo, Philippe; Reyes-Roel, Carlos

2018-03-01

A mortality episode (>90%) of triploid and diploid Pacific oysters Crassostrea gigas cultured in Baja California Sur occurred during summer 2012, coinciding with a thermal anomaly, an algal bloom, and low oxygen values. To help explain the cause of the mortalities, histological analyses and molecular tests for specific pathogens (ostreid herpesvirus 1 [OsHV-1] and Perkinsus marinus) were performed on oysters surviving at the end of the episode. Triploid oysters showed a high percentage of males (43%) and hermaphrodites (30%); 93% of these oysters were in the gonadic reabsorption stage, and in some cases, hemocytes completely filled the lumen of the gonadic follicles. Oysters presented large areas with severe hemocyte infiltration that extended toward the digestive gland. Diploid oysters showed similar gonad alterations. None of samples showed histological or molecular evidence of OsHV-1 or P. marinus. Histological alterations can be related to physiological disorders caused by the mechanism driving summer mortality. This is the first case history of a summer mortality episode among Pacific oysters in Mexico. © 2017 American Fisheries Society.

Metals concentrations in sediments and oyster Crassostrea gigas from La Pitahaya lagoon, Sinaloa, NW Mexico

NASA Astrophysics Data System (ADS)

Luna Varela, R.; Muñoz Sevilla, N.; Campos Villegas, L.; Rodriguez Espinosa, P.; Gongora Gomez, A.; MP, J.

2013-05-01

This present study was performed in a culture of Crassostrea gigas in La Pitahaya, Sinaloa, México. The main objective is to identify the enrichment pattern of trace elements (Cu, Cd, Cr, Ni, Pb, Zn, Hg, As, V) also was determine concentrations thereof in oyster. Four sampling sites were selected, two smaller channels which connect the lagoon directly , the region of culture and connection with the sea ; and each sampling consisted of 4 sample sediments and 50 oysters of commercial size per mounth . Concentrations of trace metals were determined using atomic absorption spectrophotometry (AAS). The higher concentration of elements in certain samples clearly suggests that they are directly fed by the smaller channels which connect the lagoon directly. These small channels often carry the contaminants which are absorbed and deposited in the sediments. The results were also compared with the Effect Range Low (ERL) and Effect Range Medium (ERM) of NOAA and it indicates that Ni is above the ERL values. Cadmium, lead, chrome and copper concentrations exceeded the limits permissible of bivalbe mollusks established by the sanitary regulations

Molecular diagnosis of allergy to Anisakis simplex and Gymnorhynchus gigas fish parasites.

PubMed

Armentia, A; Santos, J; Serrano, Z; Martín, B; Martín, S; Barrio, J; Fernández, S; González-Sagrado, M; Pineda, F; Palacios, R

There has been an increase in the prevalence of hypersensitivity to Anisakis simplex. There are fish parasites other than Anisakis simplex whose allergenicity has not yet been studied. To assess IgE hypersensitivity caused by fish parasite allergens in patients with gastro-allergic symptoms after consumption of fish, shellfish or cephalopods, compared with healthy subjects, pollen allergic individuals and children with digestive symptoms after eating marine food. We carried out in vivo tests (skin prick) and in vitro tests (specific IgE determination, Western blot) and component resolved diagnostics (CRD) using microarray analysis in all patients. CRD better detected sensitisation to allergens from marine parasites than skin prick tests and determination of specific IgE by CAP. Sensitisation to Gymnorhynchus gigas was detected in 26% of patients measured by skin prick tests and 36% measured by IgE. The prevalence of hypersensitivity to marine parasite allergens other than Anisakis simplex should be studied, and the most appropriate technique for this is CRD. Copyright © 2017 SEICAP. Published by Elsevier España, S.L.U. All rights reserved.

In silico cloning, expression of Rieske-like apoprotein gene and protein subcellular localization in the Pacific oyster, Crassostrea gigas.

PubMed

He, Xiaocui; Zhang, Yang; Yu, Ziniu

2010-10-01

Rieske protein gene in the Pacific oyster Crassostrea gigas was obtained by in silico cloning for the first time, and its expression profiles and subcellular localization were determined, respectively. The full-length cDNA of Cgisp is 985 bp in length and contains a 5'- and 3'-untranslated regions of 35 and 161 bp, respectively, with an open reading frame of 786 bp encoding a protein of 262 amino acids. The predicted molecular weight of 30 kDa of Cgisp protein was verified by prokaryotic expression. Conserved Rieske [2Fe-2S] cluster binding sites and highly matched-pair tertiary structure with 3CWB_E (Gallus gallus) were revealed by homologous analysis and molecular modeling. Eleven putative SNP sites and two conserved hexapeptide sequences, box I (THLGC) and II (PCHGS), were detected by multiple alignments. Real-time PCR analysis showed that Cgisp is expressed in a wide range of tissues, with adductor muscle exhibiting the top expression level, suggesting its biological function of energy transduction. The GFP tagging Cgisp indicated a mitochondrial localization, further confirming its physiological function.

Improvement in antiproliferative activity of Angelica gigas Nakai by solid dispersion formation via hot-melt extrusion and induction of cell cycle arrest and apoptosis in HeLa cells.

PubMed

Jiang, Yunyao; Piao, Jingpei; Cho, Hyun-Jong; Kang, Wie-Soo; Kim, Hye-Young

2015-01-01

Angelica gigas Nakai (AGN) is one of the most popular herbal medicines and widely used as a functional food product. In this study, AGN was firstly processed by a low-temperature turbo mill and a hot melting extruder to reduce particle size and form solid dispersion (SD). Anticancer activity against HeLa cells was then examined. AGN-SD based on Soluplus was formed via hot-melt extrusion (HME) and showed the strongest cytotoxic effect on HeLa cells. In addition, the possible mechanism of cell death induced by AGN-SD on HeLa cells was also investigated. AGN-SD decreased cell viability, induced apoptosis, increased the production of reactive oxygen species, regulated the expression of Bcl-2 and Bax, and induced G2/M phase arrest in HeLa cells. This study suggested that AGN-SD based on Soluplus and the method to improve antiproliferative effect by SD formation via HME may be suitable for application in the pharmaceutical industry.

The Neuroprotective Effects of Decursin Isolated from Angelica gigas Nakai Against Amyloid β-Protein-Induced Apoptosis in PC 12 Cells via a Mitochondria-Related Caspase Pathway.

PubMed

Li, Li; Du, Jikun; Zou, Liyi; Xia, Haishan; Wu, Tie; Kim, Yongho; Lee, Yongwoo

2015-08-01

Decursin, purified from Angelica gigas Nakai, has been proven to exert neuroprotective property. Previous study revealed decursin protected the PC12 cells from Aβ25-35-induced oxidative cytotoxicity. The present study aimed to investigate whether decursin could protect PC12 cells from apoptosis caused by Aβ. Our results indicated that pretreatment of PC12 cells with decursin significantly inhibited Aβ25-35-induced cytotoxicity and apoptosis. The mechanism of action is likely to reverse Aβ25-35-induced mitochondrial dysfunction, including the reduction of mitochondrial membrane potential, the inhibition of reactive oxygen species production, and the decrease of mitochondrial release of cytochrome c in PC12 cells. In addition, decursin significantly suppressed the activity of caspase-3 and moderated the ratio of Bcl-2/Bax induced by Aβ25-35. These findings indicate that decursin exerts a neuroprotective effect against Aβ25-35-induced neurotoxicity in PC12 cells, at least in part, via suppressing the mitochondrial pathway of cellular apoptosis.

Decursin from Angelica gigas Nakai Inhibits B16F10 Melanoma Growth Through Induction of Apoptosis

PubMed Central

Kim, Byung Soo; Seo, Hyobin; Kim, Ha-Jeong; Bae, Sang Mun; Son, Hye-Nam; Lee, Yoon Jeong; Ryu, Sungpil; Park, Rang-Woon; Nam, Ju-Ock

2015-01-01

Abstract Decursin, a bioactive phytochemical isolated from Angelica gigas Nakai (danggwi), has shown preclinical anticancer efficacy in various cancer models. However, the antitumor effect of decursin in melanoma models remains undefined. The antitumor activities of decursin were investigated in B16F10 cells in vitro and in vivo. In this study, we show that treatment with decursin inhibited cell proliferation in a dose-dependent manner in B16F10 cells, but not in normal cells. Decursin also induced apoptosis in B16F10 cells, as determined by annexin V-staining assay and transferase-mediated nick-end labeling (TUNEL) staining assay. Decursin increased the phosphorylation of p38 as well as the expression of Bax while decreasing the phosphorylation of extracellular signaling-regulated kinase (ERK) and the expression of Bcl-2 in B16F10 cells. Moreover, decursin activated caspase-3 in B16F10 cells and xenograft tumor tissue. Together, these findings support further investigations into the potential use of decursin in the treatment of melanoma cells. PMID:26336081

Decursin from Angelica gigas suppresses RANKL-induced osteoclast formation and bone loss.

PubMed

Wang, Xin; Zheng, Ting; Kang, Ju-Hee; Li, Hua; Cho, Hyewon; Jeon, Raok; Ryu, Jae-Ha; Yim, Mijung

2016-03-05

Osteoclasts are the only cells capable of breaking down bone matrix, and excessive activation of osteoclasts is responsible for bone-destructive diseases. In this study, we investigated the effects of decursin from extract of Angelica gigas root on receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclast formation using mouse bone marrow-derived macrophages (BMMs). Decursin inhibited RANKL-induced osteoclast formation without cytotoxicity. In particular, decursin maintains the characteristics of macrophages by blocking osteoclast differentiation by RANKL. Furthermore, the RANKL-stimulated bone resorption was diminished by decursin. Mechanistically, decursin blocked the RANKL-triggered ERK mitogen-activated protein kinases (MAPK) phosphorylation, which results in suppression of c-Fos and the nuclear factor of activated T cells (NFATc1) expression. In accordance with the in vitro study, decursin reduced lipopolysaccharide (LPS)- or ovariectomy (OVX)-induced bone loss in vivo. Therefore, decursin exerted an inhibitory effect on osteoclast formation and bone loss in vitro and in vivo. Decursin could be useful for the treatment of bone diseases associated with excessive bone resorption. Copyright © 2016 Elsevier B.V. All rights reserved.

Decursin from Angelica gigas Nakai Inhibits B16F10 Melanoma Growth Through Induction of Apoptosis.

PubMed

Kim, Byung Soo; Seo, Hyobin; Kim, Ha-Jeong; Bae, Sang Mun; Son, Hye-Nam; Lee, Yoon Jeong; Ryu, Sungpil; Park, Rang-Woon; Nam, Ju-Ock

2015-10-01

Decursin, a bioactive phytochemical isolated from Angelica gigas Nakai (danggwi), has shown preclinical anticancer efficacy in various cancer models. However, the antitumor effect of decursin in melanoma models remains undefined. The antitumor activities of decursin were investigated in B16F10 cells in vitro and in vivo. In this study, we show that treatment with decursin inhibited cell proliferation in a dose-dependent manner in B16F10 cells, but not in normal cells. Decursin also induced apoptosis in B16F10 cells, as determined by annexin V-staining assay and transferase-mediated nick-end labeling (TUNEL) staining assay. Decursin increased the phosphorylation of p38 as well as the expression of Bax while decreasing the phosphorylation of extracellular signaling-regulated kinase (ERK) and the expression of Bcl-2 in B16F10 cells. Moreover, decursin activated caspase-3 in B16F10 cells and xenograft tumor tissue. Together, these findings support further investigations into the potential use of decursin in the treatment of melanoma cells.

Proteus: a reconfigurable computational network for computer vision

NASA Astrophysics Data System (ADS)

Haralick, Robert M.; Somani, Arun K.; Wittenbrink, Craig M.; Johnson, Robert; Cooper, Kenneth; Shapiro, Linda G.; Phillips, Ihsin T.; Hwang, Jenq N.; Cheung, William; Yao, Yung H.; Chen, Chung-Ho; Yang, Larry; Daugherty, Brian; Lorbeski, Bob; Loving, Kent; Miller, Tom; Parkins, Larye; Soos, Steven L.

1992-04-01

The Proteus architecture is a highly parallel MIMD, multiple instruction, multiple-data machine, optimized for large granularity tasks such as machine vision and image processing The system can achieve 20 Giga-flops (80 Giga-flops peak). It accepts data via multiple serial links at a rate of up to 640 megabytes/second. The system employs a hierarchical reconfigurable interconnection network with the highest level being a circuit switched Enhanced Hypercube serial interconnection network for internal data transfers. The system is designed to use 256 to 1,024 RISC processors. The processors use one megabyte external Read/Write Allocating Caches for reduced multiprocessor contention. The system detects, locates, and replaces faulty subsystems using redundant hardware to facilitate fault tolerance. The parallelism is directly controllable through an advanced software system for partitioning, scheduling, and development. System software includes a translator for the INSIGHT language, a parallel debugger, low and high level simulators, and a message passing system for all control needs. Image processing application software includes a variety of point operators neighborhood, operators, convolution, and the mathematical morphology operations of binary and gray scale dilation, erosion, opening, and closing.

The neuroendocrine immunomodulatory axis-like pathway mediated by circulating haemocytes in pacific oyster Crassostrea gigas.

PubMed

Liu, Zhaoqun; Zhou, Zhi; Jiang, Qiufen; Wang, Lingling; Yi, Qilin; Qiu, Limei; Song, Linsheng

2017-01-01

The neuroendocrine-immune (NEI) regulatory network is a complex system, which plays an indispensable role in the immunity of host. In this study, a neuroendocrine immunomodulatory axis (NIA)-like pathway mediated by the nervous system and haemocytes was characterized in the oyster Crassostrea gigas Once invaded pathogen was recognized by the host, the nervous system would temporally release neurotransmitters to modulate the immune response. Instead of acting passively, oyster haemocytes were able to mediate neuronal immunomodulation promptly by controlling the expression of specific neurotransmitter receptors on cell surface and modulating their binding sensitivities, thus regulating intracellular concentration of Ca 2+ This neural immunomodulation mediated by the nervous system and haemocytes could influence cellular immunity in oyster by affecting mRNA expression level of TNF genes, and humoral immunity by affecting the activities of key immune-related enzymes. In summary, though simple in structure, the 'nervous-haemocyte' NIA-like pathway regulates both cellular and humoral immunity in oyster, meaning a world to the effective immune regulation of the NEI network. © 2017 The Authors.

The Japanese alga Polysiphonia morrowii (Rhodomelaceae, Rhodophyta) on the South Atlantic Ocean: first report of an invasive macroalga inhabiting oyster reefs

NASA Astrophysics Data System (ADS)

Croce, M. Emilia; Parodi, Elisa R.

2014-06-01

Conspicuous tufts of the filamentous algae Polysiphonia Greville inhabit the reefs of Crassostrea gigas on the Atlantic Patagonian coast. The population was recorded for the first time in 1994 and identified as P. argentinica. This study exhaustively investigated the morphology and reproduction of specimens and the seasonality of the population. The results revealed the identity of the specimens as the invasive Japanese macroalga Polysiphonia morrowii Harvey, on the basis of several striking features: the setaceous and tufted thalli, the corymbose growing apices, the endogenous axillary branches, the urceolate cystocarps and the sharply pointed branches. Sexual reproduction was evidenced; however, fertile male gametophytes were absent in the samples. The population was found almost all year round, but its abundance became higher in autumn and winter. The present study constitutes the first record of this invasive macroalga on the South Atlantic Ocean; the fourth record of an exotic macroalgal species on the Atlantic Patagonian coast; and the first record of an invasive species related to the establishment of C. gigas in Atlantic Patagonia.

Inheritance mode of microsatellite loci and their use for kinship analysis in the Pacific oyster ( Crassostrea gigas)

NASA Astrophysics Data System (ADS)

Li, Qi; Zheng, Xiaodong; Yu, Ruihai

2008-08-01

Five full-sib families of the Pacific oyster ( Crassostrea gigas) larvae were used to study the mode of inheritance at eight microsatellite loci, and the feasibility of these markers for kinship estimate was also examined. All eight microsatellite loci were compatible with Mendelian inheritance. Neither evidence of sex-linked barriers to transmission nor evidence of major barriers to fertilization between gametes from the parents was shown. Three of the eight loci showed the presence of null alleles in four families, demonstrating the need to conduct comprehensive species-specific inheritance studies for microsatellite loci used in population genetic studies. Although the null allele heterozygotes were considered as homozygotes in the calculation of genetic distance, offspring from five full-sib families were unambiguously discriminated in the neighbor-joining dendrogram. This result indicates that the microsatellite markers may be capable of discriminating between related and unrelated oyster larvae in the absence of pedigree information, and is applicable to the investigation of the effective number of parents contributing to the hatchery population of the Pacific oyster.

C1 finite elements on non-tensor-product 2d and 3d manifolds

PubMed Central

Nguyen, Thien; Karčiauskas, Kęstutis; Peters, Jörg

2015-01-01

Geometrically continuous (Gk) constructions naturally yield families of finite elements for isogeometric analysis (IGA) that are Ck also for non-tensor-product layout. This paper describes and analyzes one such concrete C1 geometrically generalized IGA element (short: gIGA element) that generalizes bi-quadratic splines to quad meshes with irregularities. The new gIGA element is based on a recently-developed G1 surface construction that recommends itself by its a B-spline-like control net, low (least) polynomial degree, good shape properties and reproduction of quadratics at irregular (extraordinary) points. Remarkably, for Poisson’s equation on the disk using interior vertices of valence 3 and symmetric layout, we observe O(h3) convergence in the L∞ norm for this family of elements. Numerical experiments confirm the elements to be effective for solving the trivariate Poisson equation on the solid cylinder, deformations thereof (a turbine blade), modeling and computing geodesics on smooth free-form surfaces via the heat equation, for solving the biharmonic equation on the disk and for Koiter-type thin-shell analysis. PMID:26594070

Histogenesis and disappearance of the teeth of the Mekong giant catfish, Pangasianodon gigas (Teleostei).

PubMed

Kakizawa, Yoshiko; Meenakarn, Wanpen

2003-12-01

Juveniles of the Mekong giant catfish, Pangasianodon gigas (Teleostei), have 3 sorts of tooth-upper and lower jaw teeth, palatal teeth, and pharyngeal teeth--but adults are toothless. To investigate the histogenesis and disappearance of the teeth, we made serial sections of the mouth and teeth of juvenile fish at 10 developmental stages (from ca. 8.5 to ca. 30 cm in total length) and examined them under scanning electron microscope and light microscope. Observations of teeth and surrounding tissues in the serial sections revealed the process of tooth resorption by active odontoclast-like cells. Numbers of jaw and palatal teeth decreased with age. When the fish reached ca. 14 cm in total length, the numbers of functional upper jaw teeth and successional tooth germs decreased rapidly, and the developmental rate of successional tooth germs slowed. When the fish reached ca. 24 cm, no teeth existed in the upper jaw. It is clear that tooth disappearance results from the shedding of functional teeth and the lack of replacement tooth germs.

A Low-cost 4 Bit, 10 Giga-samples-per-second Analog-to-digital Converter Printed Circuit Board Assembly for FPGA-based Backends

NASA Astrophysics Data System (ADS)

Jiang, Homin; Yu, Chen-Yu; Kubo, Derek; Chen, Ming-Tang; Guzzino, Kim

2016-11-01

In this study, a 4 bit, 10 giga-samples-per-second analog-to-digital converter (ADC) printed circuit board assembly (PCBA) was designed, manufactured, and characterized for digitizing radio telescopes. For this purpose, an Adsantec ANST7120A-KMA flash ADC chip was used. Together with the field-programmable gate array platform, developed by the Collaboration for Astronomy Signal Processing and Electronics Research community, the PCBA enables data acquisition with a wide bandwidth and simplifies the intermediate frequency section. In the current version, the PCBA and the chip exhibit an analog bandwidth of 10 GHz (3 dB loss) and 20 GHz, respectively, which facilitates second, third, and even fourth Nyquist sampling. The following average performance parameters were obtained from the first and second Nyquist zones of the three boards: a spurious-free dynamic range of 31.35/30.45 dB, a signal-to-noise and distortion ratio of 22.95/21.83 dB, and an effective number of bits of 3.65/3.43, respectively.

C1 finite elements on non-tensor-product 2d and 3d manifolds.

PubMed

Nguyen, Thien; Karčiauskas, Kęstutis; Peters, Jörg

2016-01-01

Geometrically continuous ( G k ) constructions naturally yield families of finite elements for isogeometric analysis (IGA) that are C k also for non-tensor-product layout. This paper describes and analyzes one such concrete C 1 geometrically generalized IGA element (short: gIGA element) that generalizes bi-quadratic splines to quad meshes with irregularities. The new gIGA element is based on a recently-developed G 1 surface construction that recommends itself by its a B-spline-like control net, low (least) polynomial degree, good shape properties and reproduction of quadratics at irregular (extraordinary) points. Remarkably, for Poisson's equation on the disk using interior vertices of valence 3 and symmetric layout, we observe O ( h 3 ) convergence in the L ∞ norm for this family of elements. Numerical experiments confirm the elements to be effective for solving the trivariate Poisson equation on the solid cylinder, deformations thereof (a turbine blade), modeling and computing geodesics on smooth free-form surfaces via the heat equation, for solving the biharmonic equation on the disk and for Koiter-type thin-shell analysis.

Towards decoding the conifer giga-genome.

PubMed

Mackay, John; Dean, Jeffrey F D; Plomion, Christophe; Peterson, Daniel G; Cánovas, Francisco M; Pavy, Nathalie; Ingvarsson, Pär K; Savolainen, Outi; Guevara, M Ángeles; Fluch, Silvia; Vinceti, Barbara; Abarca, Dolores; Díaz-Sala, Carmen; Cervera, María-Teresa

2012-12-01

Several new initiatives have been launched recently to sequence conifer genomes including pines, spruces and Douglas-fir. Owing to the very large genome sizes ranging from 18 to 35 gigabases, sequencing even a single conifer genome had been considered unattainable until the recent throughput increases and cost reductions afforded by next generation sequencers. The purpose of this review is to describe the context for these new initiatives. A knowledge foundation has been acquired in several conifers of commercial and ecological interest through large-scale cDNA analyses, construction of genetic maps and gene mapping studies aiming to link phenotype and genotype. Exploratory sequencing in pines and spruces have pointed out some of the unique properties of these giga-genomes and suggested strategies that may be needed to extract value from their sequencing. The hope is that recent and pending developments in sequencing technology will contribute to rapidly filling the knowledge vacuum surrounding their structure, contents and evolution. Researchers are also making plans to use comparative analyses that will help to turn the data into a valuable resource for enhancing and protecting the world's conifer forests.

High-sensitivity NMR beyond 200,000 atmospheres of pressure.

PubMed

Meier, T; Reichardt, S; Haase, J

2015-08-01

Pressure-induced changes in the chemical or electronic structure of solids require pressures well into the Giga-Pascal (GPa) range due to the strong bonding. Anvil cell designs can reach such pressures, but their small and mostly inaccessible sample chamber has severely hampered NMR experiments in the past. With a new cell design that has a radio frequency (RF) micro-coil in the high pressure chamber, NMR experiments beyond 20 Giga-Pascal are reported for the first time. (1)H NMR of water shows sensitivity and resolution obtained with the cells, and (63)Cu NMR on a cuprate superconductor (YBa2Cu3O7-δ) demonstrates that single-crystals can be investigated, as well. (115)In NMR of the ternary chalcogenide AgInTe2 discovers an insulator-metal transition with shift and relaxation measurements. The pressure cells can be mounted easily on standard NMR probes that fit commercial wide-bore magnets with regular cryostats for field- and temperature-dependent measurements ready for many applications in physics and chemistry. Copyright © 2015 Elsevier Inc. All rights reserved.

Trojan Horse Strategy for Non-invasive Interference of Clock Gene in the Oyster Crassostrea gigas.

PubMed

Payton, Laura; Perrigault, Mickael; Bourdineaud, Jean-Paul; Marcel, Anjara; Massabuau, Jean-Charles; Tran, Damien

2017-08-01

RNA interference is a powerful method to inhibit specific gene expression. Recently, silencing target genes by feeding has been successfully carried out in nematodes, insects, and small aquatic organisms. A non-invasive feeding-based RNA interference is reported here for the first time in a mollusk bivalve, the pacific oyster Crassostrea gigas. In this Trojan horse strategy, the unicellular alga Heterocapsa triquetra is the food supply used as a vector to feed oysters with Escherichia coli strain HT115 engineered to express the double-stranded RNA targeting gene. To test the efficacy of the method, the Clock gene, a central gene of the circadian clock, was targeted for knockout. Results demonstrated specific and systemic efficiency of the Trojan horse strategy in reducing Clock mRNA abundance. Consequences of Clock disruption were observed in Clock-related genes (Bmal, Tim1, Per, Cry1, Cry2, Rev.-erb, and Ror) and triploid oysters were more sensitive than diploid to the interference. This non-invasive approach shows an involvement of the circadian clock in oyster bioaccumulation of toxins produced by the harmful alga Alexandrium minutum.

Effects of low-dose exposure to pesticide mixture on physiological responses of the Pacific oyster, Crassostrea gigas.

PubMed

Geret, F; Burgeot, T; Haure, J; Gagnaire, B; Renault, T; Communal, P Y; Samain, J F

2013-12-01

This study investigated the effects on the physiology of Pacific oyster, Crassostrea gigas, of a mixture of pesticides containing 0.8 μg L(-1) alachlor, 0.6 μg L(-1) metolachlor, 0.7 μg L(-1) atrazine, 0.6 μg L(-1) terbuthylazine, 0.5 μg L(-1) diuron, 0.6 μg L(-1) fosetyl aluminum, 0.05 μg L(-1) carbaryl, and 0.7 μg L(-1) glyphosate for a total concentration of 4.55 μg L(-1) . The total nominal concentration of pesticides mixture corresponds to the pesticide concentrations in the shellfish culture area of the Marennes-Oleron basin. Two varieties of C. gigas were selected on the foreshore, based on their characteristics in terms of resistance to summer mortality, to assess the effects of the pesticide mixture after 7 days of exposure under controlled conditions. The early effects of the mixture were assessed using enzyme biomarkers of nitrogen metabolism (GS, glutamine synthetase), detoxification metabolism (GST, glutathione S-transferase), and oxidative stress (CAT, catalase). Sublethal effects on hemocyte parameters (phagocytosis and esterase activity) and DNA damages (DNA adducts) were also measured. Changes in metabolic activities were characterized by increases in GS, GST, and CAT levels on the first day of exposure for the "resistant" oysters and after 3-7 days of exposure for the "susceptible" oysters. The formation of DNA adducts was detected after 7 days of exposure. The percentage of hemocyte esterase-positive cells was reduced in the resistant oysters, as was the hemocyte phagocytic capacity in both oyster varieties after 7 days of exposure to the pesticide mixture. This study highlights the need to consider the low doses and the mixture of pesticides to evaluate the effects of these molecules on organisms. Copyright © 2011 Wiley Periodicals, Inc.

Programmable self-assembly of three-dimensional nanostructures from 104 unique components

PubMed Central

Ong, Luvena L.; Hanikel, Nikita; Yaghi, Omar K.; Grun, Casey; Strauss, Maximilian T.; Bron, Patrick; Lai-Kee-Him, Josephine; Schueder, Florian; Wang, Bei; Wang, Pengfei; Kishi, Jocelyn Y.; Myhrvold, Cameron A.; Zhu, Allen; Jungmann, Ralf

2017-01-01

Nucleic acids (DNA and RNA) are widely used to construct nanoscale structures with ever increasing complexity1–14 for possible applications in fields as diverse as structural biology, biophysics, synthetic biology and photonics. The nanostructures are formed through one-pot self-assembly, with early examples typically containing on the order of 10 unique DNA strands. The introduction of DNA origami4, which uses many staple strands to fold one long scaffold strand into a desired structure, gave access to kilo- to mega-dalton nanostructures containing about 102 unique DNA strands6,7,10,13 . Aiming for even larger DNA origami structures is in principle possible15,16, but faces the challenge of having to manufacture and route an increasingly long scaffold strand. An alternative and in principle more readily scalable approach uses DNA brick assembly8,9, which doesn’t need a scaffold and instead uses hundreds of short DNA brick strands that self-assemble according to specific inter-brick interactions. First-generation bricks used to create 3D structures are 32-nt long with four 8-nt binding domains that directed 102 distinct bricks into well-formed assemblies, but attempts to create larger structures encountered practical challenges and had limited success.9 Here we show that a new generation of DNA bricks with longer binding domains makes it possible to self-assemble 0.1 – 1 giga-dalton three-dimensional nanostructures from 104 unique components, including a 0.5 giga-dalton cuboid containing 30,000 unique bricks and a 1 giga-dalton rotationally symmetric tetramer. We also assemble a cuboid containing 10,000 bricks and 20,000 uniquely addressable ‘nano-voxels’ that serves as a molecular canvas for three-dimensional sculpting, with introduction of sophisticated user-prescribed 3D cavities yielding structures such as letters, a complex helicoid and a teddy bear. We anticipate that, with further optimization, even larger assemblies might be accessible and prove useful as scaffolds or for positioning functional components. PMID:29219968

High-Sensitivity Nuclear Magnetic Resonance at Giga-Pascal Pressures: A New Tool for Probing Electronic and Chemical Properties of Condensed Matter under Extreme Conditions

PubMed Central

Meier, Thomas; Haase, Jürgen

2014-01-01

Nuclear Magnetic Resonance (NMR) is one of the most important techniques for the study of condensed matter systems, their chemical structure, and their electronic properties. The application of high pressure enables one to synthesize new materials, but the response of known materials to high pressure is a very useful tool for studying their electronic structure and developing theories. For example, high-pressure synthesis might be at the origin of life; and understanding the behavior of small molecules under extreme pressure will tell us more about fundamental processes in our universe. It is no wonder that there has always been great interest in having NMR available at high pressures. Unfortunately, the desired pressures are often well into the Giga-Pascal (GPa) range and require special anvil cell devices where only very small, secluded volumes are available. This has restricted the use of NMR almost entirely in the past, and only recently, a new approach to high-sensitivity GPa NMR, which has a resonating micro-coil inside the sample chamber, was put forward. This approach enables us to achieve high sensitivity with experiments that bring the power of NMR to Giga-Pascal pressure condensed matter research. First applications, the detection of a topological electronic transition in ordinary aluminum metal and the closing of the pseudo-gap in high-temperature superconductivity, show the power of such an approach. Meanwhile, the range of achievable pressures was increased tremendously with a new generation of anvil cells (up to 10.1 GPa), that fit standard-bore NMR magnets. This approach might become a new, important tool for the investigation of many condensed matter systems, in chemistry, geochemistry, and in physics, since we can now watch structural changes with the eyes of a very versatile probe. PMID:25350694

Characterisation and functional comparison of single-CRD and multidomain containing galectins CgGal-2 and CgGal-3 from oyster Crassostrea gigas.

PubMed

Huang, Mengmeng; Zhou, Tao; Wu, Yuehong; Fei, Hui; Wang, Gaoyang; Li, Zhi; Lei, Yutong; Liu, Qian; Sun, Cong; Lv, Zhengbing; Xu, Xue-Wei

2018-04-18

Galectins are β-galactoside binding lectins that play crucial roles in innate immunity in vertebrates and invertebrates through their conserved carbohydrate-recognition domains (CRDs). In the present study, single- and four-CRD-containing galectins were identified in oyster Crassostrea gigas (designated CgGal-2 and CgGal-3). The open reading frames (ORFs) of CgGal-2 and CgGal-3 encode polypeptides of 200 and 555 amino acids, respectively. All CRDs of CgGal-3 include two consensus motifs essential for ligand-binding, and a novel motif is present in CgGal-2. Pathogen-associated molecular pattern (PAMP) profiles were determined for recombinant rCgGal-2 and rCgGal-3, and rCgGal-2 displayed low binding affinity for PAMPs, while rCgGal-3 bound various PAMPs including glucan, lipopolysaccharide (LPS), and peptidoglycan (PGN) with relatively high affinity. Furthermore, rCgGal-2 and rCgGal-3 exhibited different microbe binding profiles; rCgGal-2 bound to Gram-negative bacteria (Escherichia coli and Vibrio vulnificus) and fungi (Saccharomyces cerevisiae and Pichia pastoris), while rCgGal-3 bound to these microbes but also to Gram-positive bacteria (Micrococcus luteus). In addition, rCgGal-3 possessed microbial agglutinating activity and coagulation activity against fungi and erythrocytes, respectively, but rCgGal-2 lacked any agglutinating activity. Carbohydrate binding specificity analysis showed that rCgGal-3 specifically bound D-galactose. Furthermore, rCgGal-2 and rCgGal-3 functioned as opsonin participating in the clearance against invaders in C. gigas. Thus, CgGal-2 with one CRD and CgGal-3 with four CRDs are new members of the galectin family involved in immune responses against bacterial infection. Differences in the organisation and amino acid sequences of CRDs may affect their specificity and affinity for nonself substances. Copyright © 2018 Elsevier Ltd. All rights reserved.

[The occurrence and impact on survival of type 2 diabetes mellitus and thrombocytosis in colorectal cancer, before and after the surgical resection of the primary tumor].

PubMed

Herold, Zoltán; Ambrus, Viktória; Herold, Magdolna; Herczeg, György; Igaz, Péter; Harsányi, László; Somogyi, Anikó

2018-05-01

The relationship between platelets and metastatic tumor cells is an ongoing research area. Pre- and postoperative thrombocytosis are suggested predictive survival markers. Colorectal cancer and type 2 diabetes are characterized by various changes to platelets. The occurrence of colorectal cancer is more frequent in diabetes. Our aim was to determine the occurrence of type 2 diabetes in colorectal cancer patients, who attended the Semmelweis University 2nd Department of Internal Medicine's Oncology Department in the last three years. Further goals included the evaluation of anamnestic, pre- and postoperative laboratory data, and whether diabetes can be a significant survival factor. A retrospective study was conducted with 86 randomly selected colorectal cancer patients' preoperative (86 patients) and paired postoperative (66, who were operable) data. Patients were monitored no later than September 30, 2017 or until their death. Preoperatively, elevated (over 400 Giga/L) platelet counts were present in 22.1% of the patients (323.5 ± 128.63 Giga/L, mean ± SD) which decreased to 10.6% postoperatively (χ 2 : p = 0.0351; 289.2 ± 82.45 Giga/L, p = 0.0232). Negative correlation was found between platelet counts and overall survival (R: -0.35, p = 0.0085). One third of the patients had diabetes. Laboratory results (i.e., blood counts, creatinine) between diabetic and non-diabetic patients were not significant. Diabetes is a significant five-fold postoperative risk factor for shorter overall survival (relative risk: 5.1612, p = 0.0165). Average survival was 30.6 ± 26.78 months. Persistent consequential postoperative thrombocytosis may indicate shorter survival time. Our observations suggest elevated platelet counts and type 2 diabetes as prognostic markers for survival at the recognition of colorectal tumors. Orv Hetil. 2018; 159(19): 756-767.

High-sensitivity nuclear magnetic resonance at Giga-Pascal pressures: a new tool for probing electronic and chemical properties of condensed matter under extreme conditions.

PubMed

Meier, Thomas; Haase, Jürgen

2014-10-10

Nuclear Magnetic Resonance (NMR) is one of the most important techniques for the study of condensed matter systems, their chemical structure, and their electronic properties. The application of high pressure enables one to synthesize new materials, but the response of known materials to high pressure is a very useful tool for studying their electronic structure and developing theories. For example, high-pressure synthesis might be at the origin of life; and understanding the behavior of small molecules under extreme pressure will tell us more about fundamental processes in our universe. It is no wonder that there has always been great interest in having NMR available at high pressures. Unfortunately, the desired pressures are often well into the Giga-Pascal (GPa) range and require special anvil cell devices where only very small, secluded volumes are available. This has restricted the use of NMR almost entirely in the past, and only recently, a new approach to high-sensitivity GPa NMR, which has a resonating micro-coil inside the sample chamber, was put forward. This approach enables us to achieve high sensitivity with experiments that bring the power of NMR to Giga-Pascal pressure condensed matter research. First applications, the detection of a topological electronic transition in ordinary aluminum metal and the closing of the pseudo-gap in high-temperature superconductivity, show the power of such an approach. Meanwhile, the range of achievable pressures was increased tremendously with a new generation of anvil cells (up to 10.1 GPa), that fit standard-bore NMR magnets. This approach might become a new, important tool for the investigation of many condensed matter systems, in chemistry, geochemistry, and in physics, since we can now watch structural changes with the eyes of a very versatile probe.

Genomic analysis of NF-κB signaling pathway reveals its complexity in Crassostrea gigas.

PubMed

Yu, Mingjia; Chen, Jianming; Bao, Yongbo; Li, Jun

2018-01-01

NF-κB signaling pathway is an evolutionarily conserved pathway that plays highly important roles in several developmental, cellular and immune response processes. With the recent release of the draft Pacific oyster (Crassostra gigas) genome sequence, we have sought to identify the various components of the NF-κB signaling pathway in these mollusks and investigate their gene structure. We further constructed phylogenetic trees to establish the evolutionary relationship of the oyster proteins with their homologues in vertebrates and invertebrates using BLASTX and neighbor-joining method. We report the presence of two classic NF-κB/Rel homologues in the pacific oyster namely Cgp100 and CgRel, which possess characteristic RHD domain and a consensus nuclear localization signal, similar to mammalian homologues and an additional CgRel-like protein, unique to C. gigas. Further, in addition to two classical IκB homologues, CgIκB1 and CgIκB2, we have identified three atypical IκB family members namely CgIκB3, CgIκB4 and CgBCL3 which lack the IκB degradation motif and consist of only one exon that might have arisen by retrotransposition from CgIκB1. Finally, we report the presence of three IKKs and one NEMO genes in oyster genome, named CgIKK1, CgIKK2, CgIKK3 and CgNEMO, respectively. While CgIKK1 and CgIKK3 domain structure is similar to their mammalian homologues, CgIKK2 was found to lack the HLH and NBD domains. Overall, the high conservation of the NF-κB/Rel, IκB and IKK family components in the pacific oyster and their structural similarity to the vertebrate and invertebrate homologues underline the functional importance of this pathway in regulation of critical cellular processes across species. Copyright © 2017 Elsevier Ltd. All rights reserved.

Detection of Ostreid herpesvirus-1 microvariants in healthy Crassostrea gigas following disease events and their possible role as reservoirs of infection.

PubMed

Evans, Olivia; Hick, Paul; Whittington, Richard J

2017-09-01

Ostreid herpesvirus-1 microvariants (OsHV-1) cause severe mortalities in farmed Crassostrea gigas in Europe, New Zealand and Australia. Outbreaks are seasonal, recurring in the warmer months of the year in endemic estuaries. The reference genotype and microvariant genotypes of OsHV-1 have been previously detected in the tissues of apparently healthy adult oysters naturally exposed to OsHV-1 in the field. However, the role of such oysters as reservoirs of infection for subsequent mortality outbreaks remains unclear. The aims of this study were: (1) to identify the optimal sample type to use for the detection of OsHV-1 DNA in apparently healthy C. gigas; and (2) to assess whether live C. gigas maintained on-farm after an OsHV-1 related mortality event remain infected and could act as a reservoir host for subsequent outbreaks. OsHV-1 DNA was detected in the hemolymph, gill, mantle, adductor muscle, gonad and digestive gland of apparently healthy adult oysters. The likelihood of detecting OsHV-1 DNA in hemolymph was equivalent to that in gill and mantle, but the odds of detecting OsHV-1 DNA in hemolymph and gill were more than 8 times that of adductor muscle. Gill had the highest viral loads. Compared to testing whole gill homogenates, testing snippets of the gill improved the detection of OsHV-1 DNA by about four fold. The prevalence of OsHV-1 in gill and mantle was highest after the first season of OsHV-1 exposure; it then declined to low or negligible levels in the same cohorts in subsequent seasons, despite repeated seasonal exposure in monitoring lasting up to 4years. The hemolymph of individually identified oysters was repeatedly sampled over 15months, and OsHV-1 prevalence declined over that time frame in the youngest cohort, which had been exposed to OsHV-1 for the first time at the start of that season. In contrast, the prevalence in two cohorts of older oysters, which had been exposed to OsHV-1 in prior seasons, was consistently low (<10%). Viral loads were <10 4 DNA copies per mg tissue or μL hemolymph, suggesting that OsHV-1 was not being maintained at or amplified to high quantities. Therefore, while OsHV-1 may persist within apparently healthy oysters that have survived an outbreak of disease, they may not be a major reservoir host for the virus for subsequent outbreaks. However, further investigation is required to ascertain whether OsHV-1 replication occurs in surviving oysters, and whether transmission from them to naive oysters and induction of clinical disease is possible. Copyright © 2017 Elsevier Inc. All rights reserved.

GaN Initiative for Grid Applications (GIGA)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turner, George

2015-07-03

For nearly 4 ½ years, MIT Lincoln Laboratory (MIT/LL) led a very successful, DoE-funded team effort to develop GaN-on-Si materials and devices, targeting high-voltage (>1 kV), high-power, cost-effective electronics for grid applications. This effort, called the GaN Initiative for Grid Applications (GIGA) program, was initially made up of MIT/LL, the MIT campus group of Prof. Tomas Palacios (MIT), and the industrial partner M/A Com Technology Solutions (MTS). Later in the program a 4th team member was added (IQE MA) to provide commercial-scale GaN-on-Si epitaxial materials. A basic premise of the GIGA program was that power electronics, for ubiquitous utilization -evenmore » for grid applications - should be closer in cost structure to more conventional Si-based power electronics. For a number of reasons, more established GaN-on-SiC or even SiC-based power electronics are not likely to reach theses cost structures, even in higher manufacturing volumes. An additional premise of the GIGA program was that the technical focus would be on materials and devices suitable for operating at voltages > 1 kV, even though there is also significant commercial interest in developing lower voltage (< 1 kV), cost effective GaN-on-Si devices for higher volume applications, like consumer products. Remarkable technical progress was made during the course of this program. Advances in materials included the growth of high-quality, crack-free epitaxial GaN layers on large-diameter Si substrates with thicknesses up to ~5 μm, overcoming significant challenges in lattice mismatch and thermal expansion differences between Si and GaN in the actual epitaxial growth process. Such thick epilayers are crucial for high voltage operation of lateral geometry devices such as Schottky barrier (SB) diodes and high electron mobility transistors (HEMTs). New “Normally-Off” device architectures were demonstrated – for safe operation of power electronics circuits. The trade-offs between lateral and vertical devices were explored, with the conclusion that lateral devices are superior for fundamental thermal reasons, as well as for the demonstration of future generations of monolithic power circuits. As part of the materials and device investigations breakdown mechanisms in GaN-on-Si structures were fully characterized and effective electric field engineering was recognized as critical for achieving even higher voltage operation. Improved device contact technology was demonstrated, including the first gold-free metallizations (to enable processing in CMOS foundries) while maintaining low specific contact resistance needed for high-power operation and 5-order-of magnitude improvement in device leakage currents (essential for high power operation). In addition, initial GaN-on-Si epitaxial growth was performed on 8”/200 mm Si starting substrates.« less

Glossary of AWS Acrinabs. Acronyms, Initialisms, and Abbreviations Commonly Used in Air Weather Service

DTIC Science & Technology

1991-01-01

Foundation FYDP ......... Five Year Defense Plan FSI ............ Fog Stability Index 17 G G ................ gravity, giga- GISM ......... Gridded ...Global Circulation Model GOES-TAP GOES imagery processing & dissemination system GCS .......... grid course GOFS ........ Global Ocean Flux Study GD...Analysis Support System Complex Systems GRID .......... Global Resource Information Data -Base GEMAG ..... geomagnetic GRIST..... grazing-incidence solar

A flexible CPW package for a 30 GHz MMIC amplifier. [coplanar waveguide

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Taub, Susan R.

1992-01-01

A novel package, which consists of a carrier housing, has been developed for monolithic-millimeter wave Integrated Circuit amplifiers which operate at 30 giga-Hz. The carrier has coplanar waveguide (CPW) interconnects and provides heat-sinking, tuning, and cascading capabilities. The housing provides electrical isolation, mechanical protection and a feed-thru for biasing.

Aircraft Electromagnetic Compatibility.

DTIC Science & Technology

1987-06-01

Human Exposure to Radio Frequency Electromagnetic Fields , 300 KiloHertz to 100 GigaHertz." 6. ARINC 429-8, "Digital Information Transfer System (DITS...142 V EXECUTIVE SUMMARY The Aircraft Electromagnetic Compatibility guidelines document deals with electromagnetic compatibility in a... electromagnetic interference paths (figure EI. TYPE PATH 400 Hz Electrostatic MagneticCharge Electric Field Transients 5 R d t Coupling 150/i 300o Wire

A water-vapour giga-maser in the active galaxy TXFS2226-184.

PubMed

Koekemoer, A M; Henkel, C; Greenhill, L J; Dey, A; van Breugel, W; Codella, C; Antonucci, R

1995-12-14

Active galactic nuclei are thought to be powered by gas falling into a massive black hole; the different types of active galaxy may arise because we view them through a thick torus of molecular gas at varying angles of inclination. One way to determine whether the black hole is surrounded by a torus, which would obscure the accretion disk around the black hole along certain lines of sight, is to search for water masers, as these exist only in regions with plentiful molecular gas. Since the first detection of an extra-galactic water maser in 1979, they have come to be associated primarily with active galaxies, and have even been used to probe the mass of the central engine. Here we report the detection of a water giga-maser in the radio galaxy TXFS2226-184. The strength of the emission supports a recently proposed theory of maser pumping that allows for even more powerful masers, which might be detectable at cosmological distances. Water masers may accordingly provide a way to determine distances to galaxies outside the usual distance ladder, providing an independent calibration of the Hubble constant.

The modulation role of serotonin in Pacific oyster Crassostrea gigas in response to air exposure.

PubMed

Dong, Wenjing; Liu, Zhaoqun; Qiu, Limei; Wang, Weilin; Song, Xiaorui; Wang, Xiudan; Li, Yiqun; Xin, Lusheng; Wang, Lingling; Song, Linsheng

2017-03-01

Serotonin, also known as 5-hydroxytryptamine (5-HT), is a critical neurotransmitter in the neuroendocrine-immune regulatory network and involved in regulation of the stress response in vertebrates and invertebrates. In the present study, serotonin was found to be widely distributed in the tissues of Pacific oyster Crassostrea gigas, including haemolymph, gonad, visceral ganglion, mantle, gill, labial palps and hepatopancreas, and its concentration increased significantly in haemolymph and mantle after the oysters were exposed to air for 1 d. The apoptosis rate of haemocytes was significantly declined after the oysters received an injection of extra serotonin, while the activity of superoxide dismutase (SOD) in haemolymph increased significantly. After the stimulation of serotonin during air exposure, the apoptosis rate of oyster haemocytes and the concentration of H 2 O 2 in haemolymph were significantly decreased, while the SOD activity was significantly elevated. Furthermore, the survival rate of oysters from 4 th to 6 th d after injection of serotonin was higher than that of FSSW group and air exposure group. The results clearly indicated that serotonin could modulate apoptotic effect and redox during air exposure to protect oysters from stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of dermal plates from armored catfish Pterygoplichthys pardalis reveals sandwich-like nanocomposite structure.

PubMed

Ebenstein, Donna; Calderon, Carlos; Troncoso, Omar P; Torres, Fernando G

2015-05-01

Dermal plates from armored catfish are bony structures that cover their body. In this paper we characterized structural, chemical, and nanomechanical properties of the dermal plates from the Amazonian fish Pterygoplichthys pardalis. Analysis of the morphology of the plates using scanning electron microscopy (SEM) revealed that the dermal plates have a sandwich-like structure composed of an inner porous matrix surrounded by two external dense layers. This is different from the plywood-like laminated structure of elasmoid fish scales but similar to the structure of osteoderms found in the dermal armour of some reptiles and mammals. Chemical analysis performed using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) results revealed similarities between the composition of P. pardalis plates and the elasmoid fish scales of Arapaima gigas. Reduced moduli of P. pardalis plates measured using nanoindentation were also consistent with reported values for A. gigas scales, but further revealed that the dermal plate is an anisotropic and heterogeneous material, similar to many other fish scales and osteoderms. It is postulated that the sandwich-like structure of the dermal plates provides a lightweight and tough protective layer. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ethanol extract of Angelica gigas inhibits croton oil-induced inflammation by suppressing the cyclooxygenase - prostaglandin pathway

PubMed Central

Shin, Sunhee; Joo, Seong Soo; Park, Dongsun; Jeon, Jeong Hee; Kim, Tae Kyun; Kim, Jeong Seon; Park, Sung Kyeong

2010-01-01

The anti-inflammatory effects of an ethanol extract of Angelica gigas (EAG) were investigated in vitro and in vivo using croton oil-induced inflammation models. Croton oil (20 µg/mL) up-regulated mRNA expression of cyclooxygenase (COX)-I and COX-II in the macrophage cell line, RAW 264.7, resulting in the release of high concentrations of prostaglandin E2 (PGE2). EAG (1~10 µg/mL) markedly suppressed croton oil-induced COX-II mRNA expression and PGE2 production. Application of croton oil (5% in acetone) to mouse ears caused severe local erythema, edema and vascular leakage, which were significantly attenuated by oral pre-treatment with EAG (50~500 mg/kg). Croton oil dramatically increased blood levels of interleukin (IL)-6 and PGE2 without affecting tumor-necrosis factor (TNF)-α and nitric oxide (NO) levels. EAG pre-treatment remarkably lowered IL-6 and PGE2, but did not alter TNF-α or NO concentrations. These results indicate that EAG attenuates inflammatory responses in part by blocking the COX-PGE2 pathway. Therefore, EAG could be a promising candidate for the treatment of inflammatory diseases. PMID:20195064

Inducible variation in anaerobic energy metabolism reflects hypoxia tolerance across the intertidal and subtidal distribution of the Pacific oyster (Crassostrea gigas).

PubMed

Meng, Jie; Wang, Ting; Li, Li; Zhang, Guofan

2018-07-01

Pacific oyster (Crassostrea gigas) distribute a steep gradient of environmental stress between intertidal and subtidal habits and provide insight into population-scale patterns and underlying processes of variation in physiological tolerance. In this study, 1-year-old-F 1 oysters, collected from subtidal and intertidal habitats, were obtained after common garden experiment. Genetic differentiation and physiological responses under air exposure were examined to determine whether they had evolved into local adapted subpopulations. Mortality rate, anaerobic glycolysis metabolism, and energy status indicated that oyster had initiated metabolism depression and anaerobic glycolysis metabolism in both intertidal and subtidal oysters under air exposure. However, the subtidal oysters displayed the larger energy metabolism depressions and the earlier anaerobic glycolysis responses. This may indicate that subtidal oysters were more sensitives to hypoxia stress, which may lead the higher mortality rate under long term of air exposure. Based on a common garden experimental design, we propose that this diversification may have a genetic background. Overall, the clear differences between intertidal and subtidal oysters under air exposure have provided an important reference for their aquaculture and transportation used in commercial production. Copyright © 2018. Published by Elsevier Ltd.

Shell extracts of the edible mussel and oyster induce an enhancement of the catabolic pathway of human skin fibroblasts, in vitro.

PubMed

Latire, Thomas; Legendre, Florence; Bouyoucef, Mouloud; Marin, Frédéric; Carreiras, Franck; Rigot-Jolivet, Muriel; Lebel, Jean-Marc; Galéra, Philippe; Serpentini, Antoine

2017-10-01

Mollusc shells are composed of more than 95% calcium carbonate and less than 5% organic matrix consisting mostly of proteins, glycoproteins and polysaccharides. In this study, we investigated the effects of matrix macromolecular components extracted from the shells of two edible molluscs of economic interest, i.e., the blue mussel Mytilus edulis and the Pacific oyster Crassostrea gigas. The potential biological activities of these organic molecules were analysed on human dermal fibroblasts in primary culture. Our results demonstrate that shell extracts of the two studied molluscs modulate the metabolic activities of the cells. In addition, the extracts caused a decrease of type I collagen and a concomitant increase of active MMP-1, both at the mRNA and the protein levels. Therefore, our results suggest that shell extracts from M. edulis and C. gigas contain molecules that promote the catabolic pathway of human dermal fibroblasts. This work emphasises the potential use of these shell matrices in the context of anti-fibrotic strategies, particularly against scleroderma. More generally, it stresses the usefulness to valorise bivalve shells that are coproducts of shellfish farming activity.

Decursin in Angelica gigas Nakai (AGN) Enhances Doxorubicin Chemosensitivity in NCI/ADR-RES Ovarian Cancer Cells via Inhibition of P-glycoprotein Expression.

PubMed

Choi, Hyeong Sim; Cho, Sung-Gook; Kim, Min Kyoung; Kim, Min Soo; Moon, Seung Hee; Kim, Il Hwan; Ko, Seong-Gyu

2016-12-01

Angelica gigas Nakai (AGN, Korean Dang-gui) is traditionally used for the treatment of various diseases including cancer. Here, we investigated multidrug-resistant phenotype-reversal activities of AGN and its compounds (decursin, ferulic acid, and nodakenin) in doxorubicin-resistant NCI/ADR-RES ovarian cancer cells. Our results showed that a combination of doxorubicin with either AGN or decursin inhibited a proliferation of NCI/ADR-RES cells. These combinations increased the number of cells at sub-G1 phase when cells were stained with Annexin V-fluorescein isothiocyanate. We also found that these combinations activated caspase-9, caspase-8, and caspase-3 and increased cleaved PARP level. Moreover, an inhibition of P-glycoprotein expression by either AGN or decursin resulted in a reduction of its activity in NCI/ADR-RES cells. Therefore, our data demonstrate that decursin in AGN inhibits doxorubicin-resistant ovarian cancer cell proliferation and induces apoptosis in the presence of doxorubicin via blocking P-glycoprotein expression. Therefore, AGN would be a potentially novel treatment option for multidrug-resistant tumors by sensitizing to anticancer agents. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Effects of ocean acidification on immune responses of the Pacific oyster Crassostrea gigas.

PubMed

Wang, Qing; Cao, Ruiwen; Ning, Xuanxuan; You, Liping; Mu, Changkao; Wang, Chunlin; Wei, Lei; Cong, Ming; Wu, Huifeng; Zhao, Jianmin

2016-02-01

Ocean acidification (OA), caused by anthropogenic CO2emissions, has been proposed as one of the greatest threats in marine ecosystems. A growing body of evidence shows that ocean acidification can impact development, survival, growth and physiology of marine calcifiers. In this study, the immune responses of the Pacific oyster Crassostrea gigas were investigated after elevated pCO2 exposure for 28 days. The results demonstrated that OA caused an increase of apoptosis and reactive oxygen species (ROS) production in hemocytes. Moreover, elevated pCO2 had an inhibitory effect on some antioxidant enzyme activities and decreased the GSH level in digestive gland. However, the mRNA expression pattern of several immune related genes varied depending on the exposure time and tissues. After exposure to pCO2 at ∼2000 ppm for 28 days, the mRNA expressions of almost all tested genes were significantly suppressed in gills and stimulated in hemocytes. Above all, our study demonstrated that elevated pCO2 have a significant impact on the immune systems of the Pacific oyster, which may constitute as a potential threat to increased susceptibility of bivalves to diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evidence for colonization and destruction of hinge ligaments in cultured juvenile Pacific oysters (Crassostrea gigas) by cytophaga-like bacteria.

PubMed Central

Dungan, C F; Elston, R A; Schiewe, M H

1989-01-01

Several strains of cytophaga-like gliding bacteria (CLB) were isolated as numerically dominant or codominant components of bacterial populations associated with proteinaceous hinge ligaments of cultured juvenile Pacific oysters, Crassostrea gigas. These bacteria were morphologically similar to long, flexible bacilli occurring within degenerative lesions in oyster hinge ligaments. Among bacteria isolated from hinge ligaments, only CLB strains were capable of sustained growth with hinge ligament matrix as the sole source of organic carbon and nitrogen. In vitro incubation of cuboidal portions of ligament resilium with ligament CLB resulted in bacterial proliferation on the surfaces and penetration deep into ligament matrices. Bacterial proliferation was accompanied by loss of resilium structural and mechanical integrity, including complete liquefaction, at incubation temperatures between 10 and 20 degrees C. The morphological, distributional, and degradative characteristics of CLB isolated from oyster hinge ligaments provide compelling, albeit indirect, evidence that CLB are the agents of a degenerative disease affecting juvenile cultured oysters. The motility, metabolic, and hydrolytic characteristics of hinge ligament CLB and the low moles percent G + C values (32.4 to 32.9) determined for three representative strains indicate that they are marine Cytophaga spp. Images PMID:2757377

Evidence for colonization and destruction of hinge ligaments in cultured juvenile Pacific oysters (Crassostrea gigas) by cytophaga-like bacteria.

PubMed

Dungan, C F; Elston, R A; Schiewe, M H

1989-05-01

Several strains of cytophaga-like gliding bacteria (CLB) were isolated as numerically dominant or codominant components of bacterial populations associated with proteinaceous hinge ligaments of cultured juvenile Pacific oysters, Crassostrea gigas. These bacteria were morphologically similar to long, flexible bacilli occurring within degenerative lesions in oyster hinge ligaments. Among bacteria isolated from hinge ligaments, only CLB strains were capable of sustained growth with hinge ligament matrix as the sole source of organic carbon and nitrogen. In vitro incubation of cuboidal portions of ligament resilium with ligament CLB resulted in bacterial proliferation on the surfaces and penetration deep into ligament matrices. Bacterial proliferation was accompanied by loss of resilium structural and mechanical integrity, including complete liquefaction, at incubation temperatures between 10 and 20 degrees C. The morphological, distributional, and degradative characteristics of CLB isolated from oyster hinge ligaments provide compelling, albeit indirect, evidence that CLB are the agents of a degenerative disease affecting juvenile cultured oysters. The motility, metabolic, and hydrolytic characteristics of hinge ligament CLB and the low moles percent G + C values (32.4 to 32.9) determined for three representative strains indicate that they are marine Cytophaga spp.

Radiation sensitivity of poliovirus, a model for norovirus, inoculated in oyster ( Crassostrea gigas) and culture broth under different conditions

NASA Astrophysics Data System (ADS)

Jung, Pil-Mun; Park, Jae Seok; Park, Jin-Gyu; Park, Jae-Nam; Han, In-Jun; Song, Beom-Seok; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo; Baek, Min; Chung, Young-Jin; Lee, Ju-Woon

2009-07-01

Poliovirus is a recognized surrogate for norovirus, pathogen in water and food, due to the structural and genetic similarity. Although radiation sensitivity of poliovirus in water or media had been reported, there has been no research in food model such as shellfish. In this study, oyster ( Crassostrea gigas) was incubated in artificial seawater contaminated with poliovirus, and thus radiation sensitivity of poliovirus was determined in inoculated oyster. The effects of ionizing radiation on the sensitivity of poliovirus were also evaluated under different conditions such as pH (4-7) and salt concentration (1-15%) in culture broth, and temperature during irradiation. The D10 value of poliovirus in PBS buffer, virus culture broth and oyster was determined to 0.46, 2.84 and 2.94 kGy, respectively. The initial plaque forming unit (PFU) of poliovirus in culture broth was slightly decreased as the decrease of pH and the increase of salt concentration, but radiation sensitivity was not affected by pH and salt contents. However, radiation resistance of poliovirus was increased at frozen state. These results provide the basic information for the inactivation of pathogenic virus in foods by using irradiation.

Near-future levels of ocean acidification do not affect sperm motility and fertilization kinetics in the oyster Crassostrea gigas

NASA Astrophysics Data System (ADS)

Havenhand, J. N.; Schlegel, P.

2009-04-01

An increasing number of studies are now reporting the effects of ocean acidification on a broad range of marine species, processes and systems. Many of these are investigating the sensitive early life-history stages that several major reviews have highlighted as being potentially most susceptible to ocean acidification. Nonetheless there remain few investigations of the effects of ocean acidification on the very earliest, and critical, process of fertilization, and still fewer that have investigated levels of ocean acidification relevant for the coming century. Here we report the effects of near-future levels of ocean acidification (≍-0.35 pH unit change) on sperm swimming speed, sperm motility, and fertilization kinetics in a population of the Pacific oyster Crassostrea gigas from western Sweden. We found no significant effect of ocean acidification - a result that was well supported by power analysis. Similar findings from Japan suggest that this may be a globally robust result, and we emphasise the need for experiments on multiple populations from throughout a species' range. We also discuss the importance of sound experimental design and power analysis in accurate interpretation of non-significant results.

The potential of ocean acidification on suppressing larval development in the Pacific oyster Crassostrea gigas and blood cockle Arca inflata Reeve

NASA Astrophysics Data System (ADS)

Li, Jiaqi; Jiang, Zengjie; Zhang, Jihong; Mao, Yuze; Bian, Dapeng; Fang, Jianguang

2014-11-01

We evaluated the effect of pH on larval development in larval Pacific oyster ( Crassostrea gigas) and blood cockle ( Arca inflata Reeve). The larvae were reared at pH 8.2 (control), 7.9, 7.6, or 7.3 beginning 30 min or 24 h post fertilization. Exposure to lower pH during early embryonic development inhibited larval shell formation in both species. Compared with the control, larvae took longer to reach the D-veliger stage when reared under pH 7.6 and 7.3. Exposure to lower pH immediately after fertilization resulted in significantly delayed shell formation in the Pacific oyster larvae at pH 7.3 and blood cockle larvae at pH 7.6 and 7.3. However, when exposure was delayed until 24 h post fertilization, shell formation was only inhibited in blood cockle larvae reared at pH 7.3. Thus, the early embryonic stages were more sensitive to acidified conditions. Our results suggest that ocean acidification will have an adverse effect on embryonic development in bivalves. Although the effects appear subtle, they may accumulate and lead to subsequent issues during later larval development.

Near-future levels of ocean acidification do not affect sperm motility and fertilization kinetics in the oyster Crassostrea gigas

NASA Astrophysics Data System (ADS)

Havenhand, J. N.; Schlegel, P.

2009-12-01

An increasing number of studies are now reporting the effects of ocean acidification on a broad range of marine species, processes and systems. Many of these are investigating the sensitive early life-history stages that several major reviews have highlighted as being potentially most susceptible to ocean acidification. Nonetheless there remain few investigations of the effects of ocean acidification on the very earliest, and critical, process of fertilization, and still fewer that have investigated levels of ocean acidification relevant for the coming century. Here we report the effects of near-future levels of ocean acidification (≍-0.35 pH unit change) on sperm swimming speed, sperm motility, and fertilization kinetics in a population of the Pacific oyster Crassostrea gigas from western Sweden. We found no significant effect of ocean acidification - a result that was well-supported by power analysis. Similar findings from Japan suggest that this may be a globally robust result, and we emphasise the need for experiments on multiple populations from throughout a species' range. We also discuss the importance of sound experimental design and power analysis in meaningful interpretation of non-significant results.

The simple neuroendocrine-immune regulatory network in oyster Crassostrea gigas mediates complex functions.

PubMed

Liu, Zhaoqun; Wang, Lingling; Zhou, Zhi; Sun, Ying; Wang, Mengqiang; Wang, Hao; Hou, Zhanhui; Gao, Dahai; Gao, Qiang; Song, Linsheng

2016-05-19

The neuroendocrine-immune (NEI) regulatory network is a complex system, which plays an indispensable role in the immunity of the host. In the present study, the bioinformatical analysis of the transcriptomic data from oyster Crassostrea gigas and further biological validation revealed that oyster TNF (CgTNF-1 CGI_10018786) could activate the transcription factors NF-κB and HSF (heat shock transcription factor) through MAPK signaling pathway, and then regulate apoptosis, redox reaction, neuro-regulation and protein folding in oyster haemocytes. The activated immune cells then released neurotransmitters including acetylcholine, norepinephrine and [Met(5)]-enkephalin to regulate the immune response by arising the expression of three TNF (CGI_10005109, CGI_10005110 and CGI_10006440) and translocating two NF-κB (Cgp65, CGI_10018142 and CgRel, CGI_10021567) between the cytoplasm and nuclei of haemocytes. Neurotransmitters exhibited the immunomodulation effects by influencing apoptosis and phagocytosis of oyster haemocytes. Acetylcholine and norepinephrine could down-regulate the immune response, while [Met(5)]-enkephalin up-regulate the immune response. These results suggested that the simple neuroendocrine-immune regulatory network in oyster might be activated by oyster TNF and then regulate the immune response by virtue of neurotransmitters, cytokines and transcription factors.

Inheritance and Variation of Genomic DNA Methylation in Diploid and Triploid Pacific Oyster (Crassostrea gigas).

PubMed

Jiang, Qun; Li, Qi; Yu, Hong; Kong, Lingfeng

2016-02-01

DNA methylation is an important epigenetic mechanism that could be responsive to environmental changes indicating a potential role in natural selection and adaption. In order to evaluate an evolutionary role of DNA methylation, it is essential to first gain a better insight into inheritability. To address this question, this study investigated DNA methylation variation from parents to offspring in the Pacific oyster Crassostrea gigas using fluorescent-labeled methylation-sensitive amplified polymorphism (F-MSAP) analysis. Most of parental methylated loci were stably transmitted to offspring segregating following Medelian expectation. However, methylated loci deviated more often than non-methylated loci and offspring showed a few de novo methylated loci indicating DNA methylation changes from parents to offspring. Interestingly, some male-specific methylated loci were found in this study which might help to explore sex determination in oyster. Despite environmental stimuli, genomic stresses such as polyploidization also can induce methylation changes. This study also compared global DNA methylation level and individual methylated loci between diploid and triploid oysters. Results showed no difference in global methylation state but a few ploidy-specific loci were detected. DNA methylation variation during polyploidization was less than autonomous methylation variation from parents to offspring.

Evaluation of Giga-cycle Fatigue Properties of Austenitic Stainless Steels Using Ultrasonic Fatigue Test

NASA Astrophysics Data System (ADS)

Takahashi, Kyouhei; Ogawa, Takeshi

Ultrasonic fatigue tests have been performed in austenitic stainless steel, SUS316NG, in order to investigate giga-cycle fatigue strength of pre-strained materials, i.e. 5, 10 and 20% tensile pre-strains and -20% compressive pre-strain. The pre-strains were applied before specimen machining. The austenitic stainless steels are known to exhibit remarkable self-heating during the fatigue experiment. Therefore, heat radiation method was established by setting fatigue specimens in a low temperature chamber at about -100°C. The self-heating was controlled by intermittent loading condition, which enabled us to maintain the test section of the specimens at about room temperature. The results revealed that the fatigue strength increased with increasing pre-strain levels. Fish-eye fracture was observed for -20% pre-strained specimen fractured at 4.11×107 cycles, while the other specimens exhibited ordinary fatigue fracture surface originated from stage I facet on the specimen surface. The increase in fatigue limit was predicted by Vickers hardness, HV, which depended on the size of indented region. The prediction was successful using HV values obtained by the size of the indented region similar to those of the stage I facets.

A Rhodopsin-Like Gene May Be Associated With the Light-Sensitivity of Adult Pacific Oyster Crassostrea gigas

PubMed Central

Wu, Changlu; Jiang, Qiuyun; Wei, Lei; Cai, Zhongqiang; Chen, Jun; Yu, Wenchao; He, Cheng; Wang, Jiao; Guo, Wen; Wang, Xiaotong

2018-01-01

Light-sensitivity is important for mollusc survival, as it plays a vital role in reproduction and predator avoidance. Light-sensitivity has been demonstrated in the adult Pacific oyster Crassostrea gigas, but the genes associated with light-sensitivity remain unclear. In the present study, we designed experiments to identify the genes associated with light-sensitivity in adult oysters. First, we assessed the Pacific oyster genome and identified 368 genes annotated with the terms associated with light-sensitivity. Second, the function of the four rhodopsin-like superfamily member genes was tested by using RNAi. The results showed that the highest level of mRNA expression of the vision-related genes was in the mantle; however, this finding is not true for all oyster genes. Interestingly, we also found four rhodopsin-like superfamily member genes expressed at an very high level in the mantle tissue. In the RNAi experiment, when one of rhodopsin-like superfamily member genes (CGI_1001253) was inhibited, the light-sensitivity capacity of the injected oysters was significantly reduced, suggesting that CGI_10012534 may be associated with light-sensitivity in the adult Pacific oyster. PMID:29615921

Giga-seal formation alters properties of sodium channels of human myoballs.

PubMed

Fahlke, C; Rüdel, R

1992-03-01

The influence of giga-seal formation on the properties of the Na+ channels within the covered membrane patch was investigated with a whole-cell pipette and a patch pipette applied to the same cell. Current kinetics, current/voltage relation and channel densities were determined in three combinations: (i) voltage-clamping and current recording with the whole-cell pipette, (ii) voltage-clamping with the whole-cell pipette and current recording with the patch pipette and, (iii) voltage-clamping and current recording with the patch pipette. The Hodgkin-Huxley (1952) parameters tau m and tau h were smaller for the patch currents than for the whole cell, and the h infinity curve was shifted in the negative direction. The channel density was of the order of 10 times smaller. All effects were independent of the extracellular Ca2+ concentration. The capacitive current generated in the patch by the whole-cell Na+ current and its effect on the transmembrane voltage of the patch were evaluated. The kinetic parameters of the Na+ channels in the patch did not depend on whether the voltage was clamped with the whole-cell pipette or the patch pipette. Thus, the results are not due to spurious voltage.

Reductions of Vibrio parahaemolyticus in Pacific oysters (Crassostrea gigas) by depuration at various temperatures.

PubMed

Phuvasate, Sureerat; Chen, Ming-Hui; Su, Yi-Cheng

2012-08-01

Consumption of raw oysters has been linked to several outbreaks of Vibrio parahaemolyticus infection in the United States. This study investigated effects of ice storage and UV-sterilized seawater depuration at various temperatures on reducing V. parahaemolyticus in oysters. Raw Pacific oysters (Crassostrea gigas) were inoculated with a mixed culture of five clinical strains of V. parahaemolyticus (10290, 10292, 10293, BE 98-2029 and 027-1c1) at levels of 10⁴⁻⁶ MPN/g. Inoculated oysters were either stored in ice or depurated in recirculating artificial seawater at 2, 3, 7, 10, 12.5, and 15 °C for 4-6 days. Holding oysters in ice or depuration of oysters in recirculating seawater at 2 or 3 °C for 4 days did not result in significant reductions (P > 0.05) of V. parahaemolyticus in the oysters. However, depuration at temperatures between 7 and 15 °C reduced V. parahaemolyticus populations in oysters by >3.0 log MPN/g after 5 days with no loss of oysters. Depuration at refrigerated temperatures (7-15 °C) can be applied as a post-harvest treatment for reducing V. parahaemolyticus in Pacific oysters. Copyright © 2012 Elsevier Ltd. All rights reserved.

Co-Seismic Energy Changes Induced by Earthquakes on a Rotating, Gravitating Earth

NASA Technical Reports Server (NTRS)

Chao, Benjamin F.; Gross, Richard S.

2003-01-01

Besides operating its own energy budget, an earthquake acts as an agent transferring a much greater amount of energy among the Earth's rotation, elastic field, gravitational field and internal heat. We compute the co-seismic, globally integrated gravitational and rotation changes induced by some 20,000 large earthquakes that occurred in the last quarter century, according to Chao et al. (1995, GJI, 122,776- 783,784-789) and using the Harvard CMT catalog. The result confirms an extremely strong tendency for the earthquakes to decrease the global gravitational energy and to increase the spin energy. It is found that energy is being extracted from the Earth's gravitational field by the action of earthquakes at an average rate of about approx. 2 TeraW during the studied period, larger by far than the approx. 7 GigaW for the average rate of the earthquake-induced rotational energy increase and the approx. 5 GigaW for the seismic energy release. Based on energetics considerations and assuming the inability of the Earth to build up elastic energy continuously over time, it is argued that earthquakes, by converting gravitational energy, may make a significant contribution to the global hedflow.

The simple neuroendocrine-immune regulatory network in oyster Crassostrea gigas mediates complex functions

NASA Astrophysics Data System (ADS)

Liu, Zhaoqun; Wang, Lingling; Zhou, Zhi; Sun, Ying; Wang, Mengqiang; Wang, Hao; Hou, Zhanhui; Gao, Dahai; Gao, Qiang; Song, Linsheng

2016-05-01

The neuroendocrine-immune (NEI) regulatory network is a complex system, which plays an indispensable role in the immunity of the host. In the present study, the bioinformatical analysis of the transcriptomic data from oyster Crassostrea gigas and further biological validation revealed that oyster TNF (CgTNF-1 CGI_10018786) could activate the transcription factors NF-κB and HSF (heat shock transcription factor) through MAPK signaling pathway, and then regulate apoptosis, redox reaction, neuro-regulation and protein folding in oyster haemocytes. The activated immune cells then released neurotransmitters including acetylcholine, norepinephrine and [Met5]-enkephalin to regulate the immune response by arising the expression of three TNF (CGI_10005109, CGI_10005110 and CGI_10006440) and translocating two NF-κB (Cgp65, CGI_10018142 and CgRel, CGI_10021567) between the cytoplasm and nuclei of haemocytes. Neurotransmitters exhibited the immunomodulation effects by influencing apoptosis and phagocytosis of oyster haemocytes. Acetylcholine and norepinephrine could down-regulate the immune response, while [Met5]-enkephalin up-regulate the immune response. These results suggested that the simple neuroendocrine-immune regulatory network in oyster might be activated by oyster TNF and then regulate the immune response by virtue of neurotransmitters, cytokines and transcription factors.

Effects of microgravity on circadian rhythms in insects

NASA Technical Reports Server (NTRS)

Alpatov, A. M.; Hoban-Higgins, T. M.; Fuller, C. A.; Lazarev, A. O.; Rietveld, W. J.; Tschernyshev, V. B.; Tumurova, E. G.; Wassmer, G.; Zotov, V. A.

1998-01-01

The desert beetle Trigonoscelis gigas Reitt. was used as a biological model in studies that examined the effects of space flight on the circadian timing system. Results from studies aboard the Bion-10, Bion-11, and Photon-11 missions are reported. The control study is an ongoing Mir experiment. The studies indicate that the free-running period in beetles may be longer during space flight.

Ion Channel Conductance Measurements on a Silicon-Based Platform

DTIC Science & Technology

2006-01-01

calculated using the molecular dynamics code, GROMACS . Reasonable agreement is obtained in the simulated versus measured conductance over the range of...measurements of the lipid giga-seal characteristics have been performed, including AC conductance measurements and statistical analysis in order to...Dynamics kernel self-consistently coupled to Poisson equations using a P3M force field scheme and the GROMACS description of protein structure and

CgIκB3, the third novel inhibitor of NF-kappa B (IκB) protein, is involved in the immune defense of the Pacific oyster, Crassostrea gigas.

PubMed

Xu, Fengjiao; Li, Jun; Zhang, Yuehuan; Li, Xiaomei; Zhang, Yang; Xiang, Zhiming; Yu, Ziniu

2015-10-01

Inhibitor of NF-κB (IκB), the important regulator of NF-κB/Rel signaling pathway, plays the crucial role in immune response of both vertebrates and invertebrates. Here, a novel homologue of IκB was cloned from Crassostrea gigas, and designated as CgIκB3. The complete CgIκB3 cDNA was 1282 bp in length, including a 942 bp open reading frame (ORF), a 51 bp 5' UTR and a 289 bp 3' UTR. The ORF encodes a putative protein of 313 amino acids with a predicted molecular weight of approximately 34.7 kDa. Sequence analysis reveals that CgIκB3 contains a conserved degradation motif but with only five ankyrin repeats. Neither a PEST domain nor a C-terminal casein kinase II phosphorylation site was identified through either alignment or bioinformatic prediction. Phylogenetic analysis suggested that CgIκB3 shares common ancestor with CgIκB1 rather CgIκB2, and theoretically it may originate from one duplication event prior to divergence of CgIκB1 and CgIκB2. Tissue expression analyses demonstrated that CgIκB3 mRNA is the most abundant in gills and heart. The expression following PAMP infection showed that CgIκB3 was significantly up-regulated in a similar pattern when challenged with LPS, HKLM or HKVA, respectively. Moreover, similar to CgIκB1 and CgIκB2, CgIκB3 can also inhibit Rel dependent NF-κB activation in HEK293 cells in a dose-dependent manner. In summary, these findings suggest that CgIκB3 can be as the functional inhibitor of NF-κB/Rel and involved in the host defense of C. gigas. The discovery of the third IκB emphasizes the complexity and importance of the regulation on NF-κB activation. Copyright © 2015 Elsevier Ltd. All rights reserved.

ESO unveils an amazing, interactive, 360-degree panoramic view of the entire night sky

NASA Astrophysics Data System (ADS)

2009-09-01

The first of three images of ESO's GigaGalaxy Zoom project - a new magnificent 800-million-pixel panorama of the entire sky as seen from ESO's observing sites in Chile - has just been released online. The project allows stargazers to explore and experience the Universe as it is seen with the unaided eye from the darkest and best viewing locations in the world. This 360-degree panoramic image, covering the entire celestial sphere, reveals the cosmic landscape that surrounds our tiny blue planet. This gorgeous starscape serves as the first of three extremely high-resolution images featured in the GigaGalaxy Zoom project, launched by ESO within the framework of the International Year of Astronomy 2009 (IYA2009). GigaGalaxy Zoom features a web tool that allows users to take a breathtaking dive into our Milky Way. With this tool users can learn more about many different and exciting objects in the image, such as multicoloured nebulae and exploding stars, just by clicking on them. In this way, the project seeks to link the sky we can all see with the deep, "hidden" cosmos that astronomers study on a daily basis. The wonderful quality of the images is a testament to the splendour of the night sky at ESO's sites in Chile, which are the most productive astronomical observatories in the world. The plane of our Milky Way Galaxy, which we see edge-on from our perspective on Earth, cuts a luminous swath across the image. The projection used in GigaGalaxy Zoom place the viewer in front of our Galaxy with the Galactic Plane running horizontally through the image - almost as if we were looking at the Milky Way from the outside. From this vantage point, the general components of our spiral galaxy come clearly into view, including its disc, marbled with both dark and glowing nebulae, which harbours bright, young stars, as well as the Galaxy's central bulge and its satellite galaxies. The painstaking production of this image came about as a collaboration between ESO, the renowned French writer and astrophotographer Serge Brunier and his fellow Frenchman Frédéric Tapissier. Brunier spent several weeks during the period between August 2008 and February 2009 capturing the sky, mostly from ESO observatories at La Silla and Paranal in Chile. In order to cover the full Milky Way, Brunier also made a week-long trip to La Palma, one of the Canary Islands, to photograph the northern skies [1]. Once the raw photographs were in hand, image processing by Tapissier and ESO experts helped to convey accurately the night sky as our eyes behold it [2]. The resulting image, now available on GigaGalaxy Zoom, is composed of almost 300 fields each individually captured by Brunier four times, adding up to nearly 1200 photos that encompass the entire night sky. "I wanted to show a sky that everyone can relate to - with its constellations, its thousands of stars, with names familiar since childhood, its myths shared by all civilisations since Homo became Sapiens," says Brunier. "The image was therefore made as man sees it, with a regular digital camera under the dark skies in the Atacama Desert and on La Palma." As photographing extended over several months, objects from the Solar System came and went through the star fields, with bright planets such as Venus and Jupiter. A brilliant, emerald-green comet also flew by, although spotting it among a background of tens of millions of stars will be difficult (but rewarding). Overall, the creators of the GigaGalaxy Zoom project hope that these tremendous efforts in bringing the night sky as observed under the best conditions on the planet to stargazers everywhere will inspire awe for the beautiful, immense Universe that we live in. "The vision of the IYA2009 is to help people rediscover their place in the Universe through the day- and night-time sky, and this is exactly what the GigaGalaxy Zoom project is all about," says project coordinator Henri Boffin. The second dramatic GigaGalaxy Zoom image will be revealed next week, on 21 September 2009. Notes [1] During his quest, Brunier used a Nikon D3 digital camera. The apparent motion of the sky caused by Earth's rotation was corrected for using a small, precise equatorial mount moving in the opposite direction, which made a whole circle in 23 hours 56 minutes around the Earth's axis of rotation. Each photo required a six-minute exposure, for a total exposure time of more than 120 hours. [2] The data processing, using software called Autopano Pro Giga, took great care in respecting the colours and "texture" of the Milky Way. Frédéric Tapissier needed about 340 computing hours on a powerful PC to complete the task. More information As part of the IYA2009, ESO is participating in several remarkable outreach activities, in line with its world-leading rank in the field of astronomy. ESO is hosting the IYA2009 Secretariat for the International Astronomical Union, which coordinates the Year globally. ESO is one of the Organisational Associates of IYA2009, and was also closely involved in the resolution submitted to the United Nations (UN) by Italy, which led to the UN's 62nd General Assembly proclaiming 2009 the International Year of Astronomy. In addition to a wide array of activities planned both at the local and international level, ESO is leading three of the twelve global Cornerstone Projects. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky". Serge Brunier is a French journalist, photographer and writer who specialises in popularising astronomy. He is a regular contributor to Science & Vie magazine, and to the France Info radio station. He has written numerous popular astronomy books, translated into over ten languages, and is a prize-winning photographer, who has captured images of solar eclipses from the most amazing places in the world. A life-long quest for the best skies in the world led him to Chile. This whole sky panorama was presented from 25 August till 13 September 2009 in the exhibition "Un ciel pour la planète" (A sky for the planet) in the Atrium of the Monte-Carlo Casino, Monaco. With a giant print of 12 times 6 metres, the exhibition was under the Patronage of The Prince Albert II of Monaco, and showed with images and videos the making of this unique ESO project.

Program Management 2000: Know the Way

DTIC Science & Technology

2000-01-01

Conferences Knowledge Market Researchers Jupiter Meta Forrester Business Intelligence Gartner Giga Delphi DataQuest 94 •> 98 Knowledge Publications...Explicit and Tacit 2-4 Figure 2-4. How Tacit Knowledge Becomes Explicit 2-5 Figure 2-5. Knowledge-Based Barriers and Solutions 2-7 Figure 2-6. Business ...television program, World Business Review, I have seen how private industry is using technology to improve the knowledge of its workers. Organizations

Multiresolution Algorithms for Processing Giga-Models: Real-time Visualization, Reasoning, and Interaction

DTIC Science & Technology

2012-04-23

Interactive Virtual Hair Salon , Presence, (05 2007): 237. doi: 2012/04/17 12:55:26 31 Theodore Kim, Jason Sewall, Avneesh Sud, Ming Lin. Fast...in Games , Utrecht, Netherlands, Nov. 2009. Keynote Speaker, IADIS International Conference on Computer Graphics and Visualization, Portugal, June 2009...Keynote Speaker, ACM Symposium on Virtual Reality Software and Technology, Bordeaux, France, October 2008. Invited Speaker, Motion in Games , Utrecht

A wide-band, high-resolution spectrum analyzer

NASA Technical Reports Server (NTRS)

Wilck, H. C.; Quirk, M. P.; Grimm, M. J.

1985-01-01

A million-channel, 20 MHz-bandwidth, digital spectrum analyzer under evelopment for use in the SETI Sky Survey and other applications in the Deep Space Network is described. The analyzer digitizes an analog input, performs a 2(20)-point Radix-2, Fast Fourier Transform, accumulates the output power, and normalizes the output to remove frequency-dependent gain. The effective speed of the real-time hardware is 2.2 GigaFLOPS.

Note: A portable, light-emitting diode-based ruby fluorescence spectrometer for high-pressure calibration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng Yejun

2011-04-15

Ruby (Al{sub 2}O{sub 3}, with {approx}0.5 wt. % Cr doping) is one of the most widely used manometers at the giga-Pascal scale. Traditionally, its fluorescence is excited with intense laser sources. Here, I present a simple, robust, and portable design that employs light-emitting diodes (LEDs) instead. This LED-based system is safer in comparison with laser-based ones.

Mining the transcriptomes of four commercially important shellfish species for single nucleotide polymorphisms within biomineralization genes.

PubMed

Vendrami, David L J; Shah, Abhijeet; Telesca, Luca; Hoffman, Joseph I

2016-06-01

Transcriptional profiling not only provides insights into patterns of gene expression, but also generates sequences that can be mined for molecular markers, which in turn can be used for population genetic studies. As part of a large-scale effort to better understand how commercially important European shellfish species may respond to ocean acidification, we therefore mined the transcriptomes of four species (the Pacific oyster Crassostrea gigas, the blue mussel Mytilus edulis, the great scallop Pecten maximus and the blunt gaper Mya truncata) for single nucleotide polymorphisms (SNPs). Illumina data for C. gigas, M. edulis and P. maximus and 454 data for M. truncata were interrogated using GATK and SWAP454 respectively to identify between 8267 and 47,159 high quality SNPs per species (total=121,053 SNPs residing within 34,716 different contigs). We then annotated the transcripts containing SNPs to reveal homology to diverse genes. Finally, as oceanic pH affects the ability of organisms to incorporate calcium carbonate, we honed in on genes implicated in the biomineralization process to identify a total of 1899 SNPs in 157 genes. These provide good candidates for biomarkers with which to study patterns of selection in natural or experimental populations. Copyright © 2016 Elsevier B.V. All rights reserved.

Impact of logging on the foraging behaviour of two sympatric species of Couas (Coua coquereli and Coua gigas) in the western dry forest of Madagascar.

PubMed

Chouteau, Philippe

2009-06-01

Two ground-dwelling couas species, Coquerel's Coua Coua coquereli and Giant Coua Coua gigas, live in sympatry in the dry forest of Madagascar. These birds are typically insectivorous and mainly feed at ground level. The two species differ by size but have the same morphology, suggesting they have the same physical attributes for foraging and prey capture. To test if the two species have the same foraging behaviour, and also to know how habitat disturbance due to logging could affect their foraging behaviour, I compared and analysed the foraging strategies of both species in two different dry forest habitats: unlogged and logged. The two species differed in their foraging behaviour between the two habitats, mainly by the ability to climb in the vegetation, and by the technique used by both species. Coquerel's Coua used more often gleaning and probing in the unlogged forest, while Giant Coua used lunge more often in this habitat. The giant Coua used also more often leaves as a substrate in the logged forest. Some modifications in the diet have been recorded too. These results suggest that anthropogenic disturbance of forest does influence the foraging behaviour of the terrestrial couas species living in the dry forest in Madagascar.

Accelerating Smith-Waterman Algorithm for Biological Database Search on CUDA-Compatible GPUs

NASA Astrophysics Data System (ADS)

Munekawa, Yuma; Ino, Fumihiko; Hagihara, Kenichi

This paper presents a fast method capable of accelerating the Smith-Waterman algorithm for biological database search on a cluster of graphics processing units (GPUs). Our method is implemented using compute unified device architecture (CUDA), which is available on the nVIDIA GPU. As compared with previous methods, our method has four major contributions. (1) The method efficiently uses on-chip shared memory to reduce the data amount being transferred between off-chip video memory and processing elements in the GPU. (2) It also reduces the number of data fetches by applying a data reuse technique to query and database sequences. (3) A pipelined method is also implemented to overlap GPU execution with database access. (4) Finally, a master/worker paradigm is employed to accelerate hundreds of database searches on a cluster system. In experiments, the peak performance on a GeForce GTX 280 card reaches 8.32 giga cell updates per second (GCUPS). We also find that our method reduces the amount of data fetches to 1/140, achieving approximately three times higher performance than a previous CUDA-based method. Our 32-node cluster version is approximately 28 times faster than a single GPU version. Furthermore, the effective performance reaches 75.6 giga instructions per second (GIPS) using 32 GeForce 8800 GTX cards.

Assessment of sediment contamination by spermiotoxicity and embryotoxicity bioassays with sea urchins (Paracentrotus lividus) and oysters (Crassostrea gigas).

PubMed

Geffard, O; Budzinski, H; Augagneur, S; Seaman, M N; His, E

2001-07-01

Gametes (sperm) and fertilized eggs (embryos) of the Mediterranean sea urchin, Paracentrotus lividus, and the Japanese oyster, Crassostrea gigas, were used to investigate the toxicity of two marine sediments, one polluted by polycyclic aromatic hydrocarbons (PAH) and the other by heavy metals. The sediment samples were freeze-dried for storage, and three different treatments were used for analysis: whole sediment, unfiltered elutriate, and filtered elutriate. The two sediments were toxic to sea urchin spermatozoa but not to oyster spermatozoa, and embryotoxicity was almost always the more sensitive endpoint for toxicity assessment. As a rule, whole sediment was more toxic than the elutriates by nearly two orders of magnitude. With respect to embryotoxicity, the whole sediments and the elutriates of the PAH-contaminated sediment were more toxic to oyster embryos, whereas the elutriates of the sediment polluted by heavy metals had stronger effects on sea urchin embryos. The results confirm that bioassays with Japanese oyster embryos provide a more sensitive appraisal of toxicity in the marine environment than bioassays with other developmental stages. As a whole, Mediterranean sea urchins and Japanese oysters were similar in overall sensitivity and are therefore both equally suited as bioassay organisms, but tests with oysters are more reproducible because of the better performance of the controls.

A New Herbal Formula, KSG-002, Suppresses Breast Cancer Growth and Metastasis by Targeting NF-κB-Dependent TNFα Production in Macrophages

PubMed Central

Woo, Sang-Mi; Choi, Youn Kyung; Cho, Sung-Gook; Park, Sunju; Ko, Seong-Gyu

2013-01-01

Tumor-associated macrophages (TAMs) in tumor microenvironment regulate cancer progression and metastases. In breast cancer, macrophage infiltration is correlated with a poor prognosis. While metastatic breast cancer is poor prognostic with a severe mortality, therapeutic options are still limited. In this study, we demonstrate that KSG-002, a new herbal composition of radices Astragalus membranaceus and Angelica gigas, suppresses breast cancer via inhibiting TAM recruitment. KSG-002, an extract of radices Astragalus membranaceus and Angelica gigas at 3 : 1 ratio, respectively, inhibited MDA-MB-231 xenograft tumor growth and pulmonary metastasis in nude mice, while KSG-001, another composition (1 : 1 ratio, w/w), enhanced tumor growth, angiogenesis, and pulmonary metastasis, in vivo. KSG-002 further decreased the infiltrated macrophage numbers in xenograft tumor cohorts. In Raw264.7 cells, KSG-002 but not KSG-001 inhibited cell proliferation and migration and reduced TNF-alpha (TNFα) production by inhibiting NF-κB pathway. Furthermore, a combinatorial treatment of KSG-002 with TNFα inhibited a proliferation and migration of both MDA-MB-231 and Raw264.7 cells. Taken together, we conclude that KSG-002 suppresses breast cancer growth and metastasis through targeting NF-κB-mediated TNFα production in macrophages. PMID:23818931

The granulocytes are the main immunocompetent hemocytes in Crassostrea gigas.

PubMed

Wang, Weilin; Li, Meijia; Wang, Lingling; Chen, Hao; Liu, Zhaoqun; Jia, Zhihao; Qiu, Limei; Song, Linsheng

2017-02-01

Hemocytes comprise diverse cell types with morphological and functional heterogeneity and play indispensable roles in immunological homeostasis of invertebrates. The morphological classification of different hemocytes in mollusk has been studied since the 1970's, yet the involvement of the different sub-populations in immune functions is far from clear. In the present study, three types of hemocytes were morphologically identified and separated as agranulocytes, semi-granulocytes and granulocytes by flow cytometry and Percoll ® density gradient centrifugation. The granulocytes were characterized functionally as the main phagocytic and encapsulating population, while semi-granulocytes and agranulocytes exhibited low or no such capacities, respectively. Meanwhile, the lysosome activity and the productions of ROS and NO were all mainly concentrated in granulocytes under both normal and immune-activated situations. Further, the mRNA transcripts of some immune related genes, including CgTLR, CgClathrin, CgATPeV, CgLysozyme, CgDefensin and CgIL-17, were mainly expressed in granulocytes, lower in semi-granulocytes and agranulocytes. These results collectively suggested that the granulocytes were the main immunocompetent hemocytes in oyster C. gigas, and a differentiation relationship among these three sub-population hemocytes was inferred based on the gradual changes in morphological, functional and molecular features. Copyright © 2016 Elsevier Ltd. All rights reserved.

Decursin, an active compound isolated from Angelica gigas, inhibits fat accumulation, reduces adipocytokine secretion and improves glucose tolerance in mice fed a high-fat diet.

PubMed

Hwang, Jin-Taek; Kim, Sung Hee; Hur, Haeng Jeon; Kim, Hyun Jin; Park, Jae Ho; Sung, Mi Jeong; Yang, Hye Jeong; Ryu, Shi Yong; Kim, Young Sup; Cha, Mi Ran; Kim, Myung Sunny; Kwon, Dae Young

2012-05-01

Decursin (De), an active component of Angelica gigas, is known to exert anticancer and neuroprotective effects. However, its antiobesity and antidiabetic potential has not yet been investigated. This study evaluated the antiobesity effect of decursin, particularly focusing on its ability to inhibit adipocyte differentiation in 3T3-L1 cells. Decursin treatment resulted in the inhibition of adipocyte differentiation and the expression of fatty acid synthase. The study further investigated these antiobesity effects using mice fed a normal diet (ND), a high-fat diet (HFD) and a HFD plus decursin 200 mg/kg diet (HFD + De) for 7 weeks. Mice administered HFD plus decursin showed a drastic decrease in weight gain, triglyceride content, total cholesterol content and fat size compared with those that received the HFD alone; this was observed despite similar quantities of total food intake. Furthermore, decursin improved glucose tolerance in mice fed a HFD. Finally, administration of decursin along with the HFD significantly reduced the secretion of HFD-induced adipocytokines such as leptin, resistin, IL-6 and MCP-1. These results suggest that decursin might be useful for the treatment of obesity and diabetes. Copyright © 2011 John Wiley & Sons, Ltd.

In vivo anti-cancer activity of Korean Angelica gigas and its major pyranocoumarin decursin.

PubMed

Lee, Hyo Jeong; Lee, Hyo Jung; Lee, Eun Ok; Lee, Jae Ho; Lee, Kuen Sung; Kim, Kwan Hyun; Kim, Sung-Hoon; Lü, Junxuan

2009-01-01

We have reported that a 10-herbal traditional formula containing Korean Angelica gigas Nakai (AGN) exerts potent anti-cancer efficacy and identified decursin and decursinol angelate (DA) from AGN as novel anti-androgens. Here, we determined whether AGN would exert in vivo anti-cancer activity and whether decursin or DA could account for its efficacy. The AGN ethanol extract was tested against the growth of mouse Lewis lung cancer (LLC) allograft in syngenic mice or human PC-3 and DU145 prostate cancer xenograft in immunodeficient mice. The pharmacokinetics of decursin and DA were determined. The AGN extract significantly inhibited LLC allograft growth (30 mg/kg) and PC-3 and DU145 xenograft growth (100 mg/kg) without affecting the body weight of the host mice. Biomarker analyses revealed decreased cell proliferation (Ki67, PCNA), decreased angiogenesis (VEGF, microvessel density) and increased apoptosis (TUNEL, cPARP) in treated tumors. Decursin and DA injected intraperitoneally were rapidly hydrolyzed to decursinol. Decursinol and decursin at 50 mg/kg inhibited LLC allograft growth to the same extent, comparable to 30 mg AGN/kg. Therefore the AGN extract possessed significant in vivo anti-cancer activity, but decursin and DA only contributed moderately to that activity, most likely through decursinol.

Population resequencing reveals candidate genes associated with salinity adaptation of the Pacific oyster Crassostrea gigas.

PubMed

She, Zhicai; Li, Li; Meng, Jie; Jia, Zhen; Que, Huayong; Zhang, Guofan

2018-06-06

The Pacific oyster Crassostrea gigas is an important cultivated shellfish. As a euryhaline species, it has evolved adaptive mechanisms responding to the complex and changeable intertidal environment that it inhabits. To investigate the genetic basis of this salinity adaptation mechanism, we conducted a genome-wide association study using phenotypically differentiated populations (hyposalinity and hypersalinity adaptation populations, and control population), and confirmed our results using an independent population, high-resolution melting, and mRNA expression analysis. For the hyposalinity adaptation, we determined 24 genes, including Cg_CLCN7 (chloride channel protein 7) and Cg_AP1 (apoptosis 1 inhibitor), involved in the ion/water channel and transporter mechanisms, free amino acid and reactive oxygen species metabolism, immune responses, and chemical defence. Three SNPs located on these two genes were significantly differentiated between groups, as was Cg_CLCN7. For the hypersalinity adaptation, the biological process for positive regulating the developmental process was enriched. Enriched gene functions were focused on transcriptional regulation, signal transduction, and cell growth and differentiation, including calmodulin (Cg_CaM) and ficolin-2 (Cg_FCN2). These genes and polymorphisms possibly play an important role in oyster hyposalinity and hypersalinity adaptation. They not only further our understanding of salinity adaptation mechanisms but also provide markers for highly adaptable oyster strains suitable for breeding.

Characterization of GnRH-related peptides from the Pacific oyster Crassostrea gigas.

PubMed

Bigot, Laetitia; Zatylny-Gaudin, Céline; Rodet, Franck; Bernay, Benoit; Boudry, Pierre; Favrel, Pascal

2012-04-01

Gonadotropin-releasing hormone (GnRH), a key neuropeptide regulating reproduction in vertebrates has now been characterized in a number of non-vertebrate species. Despite the demonstration of its ancestral origin, the structure and the function of this family of peptides remain poorly known in species as distant as lophotrochozoans. In this study, two GnRH-related peptides (Cg-GnRH-a and CgGnRH-G) were characterized by mass spectrometry from extracts of the visceral ganglia of the Pacific oyster Crassostrea gigas. These peptides showed a high degree of sequence identity with GnRHs of other mollusks and annelids and to a lesser extent with those of vertebrates or with AKH and corazonins of insects. Both the mature peptides and the transcript encoding the precursor protein were exclusively expressed in the visceral ganglia. Significant differences in transcriptional activity of Cg-GnRH encoding gene were recorded in the ganglia along the reproductive cycle and according to trophic conditions with a higher level in fed animals compared to starved animals. This suggests the involvement of Cg-GnRHs as synchronizers of nutritional status with energy requirements during reproduction in oyster. Evidence for a role of Cg-GnRHs as neuroregulators and as neuroendocrine factors in bivalve is discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

Angelica gigas Nakai and Soluplus-Based Solid Formulations Prepared by Hot-Melting Extrusion: Oral Absorption Enhancing and Memory Ameliorating Effects

PubMed Central

Piao, Jingpei; Lee, Jae-Young; Weon, Jin Bae; Ma, Choong Je; Ko, Hyun-Jeong; Kim, Dae-Duk; Kang, Wie-Soo; Cho, Hyun-Jong

2015-01-01

Oral solid formulations based on Angelica gigas Nakai (AGN) and Soluplus were prepared by the hot-melting extrusion (HME) method. AGN was pulverized into coarse and ultrafine particles, and their particle size and morphology were investigated. Ultrafine AGN particles were used in the HME process with high shear to produce AGN-based formulations. In simulated gastrointestinal fluids (pH 1.2 and pH 6.8) and water, significantly higher amounts of the major active components of AGN, decursin (D) and decursinol angelate (DA), were extracted from the HME-processed AGN/Soluplus (F8) group than the AGN EtOH extract (ext) group (p < 0.05). Based on an in vivo pharmacokinetic study in rats, the relative oral bioavailability of decursinol (DOH), a hepatic metabolite of D and DA, in F8-administered mice was 8.75-fold higher than in AGN EtOH ext-treated group. In scopolamine-induced memory-impaired mice, F8 exhibited a more potent cognitive enhancing effect than AGN EtOH ext in both a Morris water maze test and a passive avoidance test. These findings suggest that HME-processed AGN/Soluplus formulation (F8) could be a promising therapeutic candidate for memory impairment. PMID:25915423

A Preliminary Study on the Pattern, the Physiological Bases and the Molecular Mechanism of the Adductor Muscle Scar Pigmentation in Pacific Oyster Crassostrea gigas

PubMed Central

Yu, Wenchao; He, Cheng; Cai, Zhongqiang; Xu, Fei; Wei, Lei; Chen, Jun; Jiang, Qiuyun; Wei, Na; Li, Zhuang; Guo, Wen; Wang, Xiaotong

2017-01-01

The melanin pigmentation of the adductor muscle scar and the outer surface of the shell are among attractive features and their pigmentation patterns and mechanism still remains unknown in the Pacific oyster Crassostrea gigas. To study these pigmentation patterns, the colors of the adductor muscle scar vs. the outer surface of the shell on the same side were compared. No relevance was found between the colors of the adductor muscle scars and the corresponding outer surface of the shells, suggesting that their pigmentation processes were independent. Interestingly, a relationship between the color of the adductor muscle scars and the dried soft-body weight of Pacific oysters was found, which could be explained by the high hydroxyl free radical scavenging capacity of the muscle attached to the black adductor muscle scar. After the transcriptomes of pigmented and unpigmented adductor muscles and mantles were studied by RNAseq and compared, it was found that the retinol metabolism pathway were likely to be involved in melanin deposition on the adductor muscle scar and the outer surface of the shell, and that the different members of the tyrosinase or Cytochrome P450 gene families could play a role in the independent pigmentation of different organs. PMID:28955252

Seasonality influence on biochemical and hematological indicators of stress and growth of pirarucu (Arapaima gigas), an Amazonian air-breathing fish.

PubMed

Bezerra, Rosiely Felix; Soares, Maria do Carmo Figueiredo; Santos, Athiê Jorge Guerra; Carvalho, Elba Verônica Matoso Maciel; Coelho, Luana Cassandra Breitenbach Barroso

2014-01-01

Environmental factors such as seasonal cycles are the main chronic stress cause in fish increasing incidence of disease and mortality and affecting productive performance. Arapaima gigas (pirarucu) is an Amazonian air-breathing and largest freshwater fish with scales in the world. The captivity development of pirarucu is expanding since it can fatten up over 1 kg per month reaching 10 kg body mass in the first year of fattening. This work was conducted in three periods (April to July 2010, August to November 2010, and December 2010 to March 2011) defined according to rainfall and medium temperatures. Seasonality effect analysis was performed on biochemical (lectin activity, lactate dehydrogenase, and alkaline phosphatase activities) and hematological (total count of red blood cells, hematocrit, hemoglobin, and hematimetric Wintrobe indexes) stress indicators, as well as on growth and wellbeing degree expressed by pirarucu condition factor developed in captivity. All biochemical and hematological stress indicators showed seasonal variations. However, the fish growth was allometrically positive; condition factor high values indicated good state of healthiness in cultivation. These results reinforce the robust feature of pirarucu and represent a starting point for understanding stress physiology and environmental changes during cultivation enabling identification and prevention of fish adverse health conditions.

Sterol patterns of cultured zooxanthellae isolated from marine invertebrates: Synthesis of gorgosterol and 23-desmethylgorgosterol by aposymbiotic algae.

PubMed

Withers, N W; Kokke, W C; Fenical, W; Djerassi, C

1982-06-01

QUANTITATIVE STEROL COMPOSITIONS OF CULTURED ZOOXANTHELLAE ISOLATED FROM VARIOUS PACIFIC AND ATLANTIC INVERTEBRATE HOSTS: Zoanthus sociatus (a zoanthid), Oculina diffusa (a scleractian coral), Tridacna gigas (a giant clam), Melibe pilosa (a nudibranch), and Aiptasia pulchella (a sea anemone) are reported. The results clearly demonstrate large differences in sterol patterns of zooxanthellae and that there is no obvious relationship between the taxonomic affiliation of the host and the sterol pattern of its isolated symbiont. The sterols of the zooxanthellae of O. diffusa (Cnidaria) and T. gigas (Mollusca) are qualitatively equivalent. Based on the structures of the two major free sterols synthesized by each alga, the zooxanthellae from different hosts were separated into three distinct groups. It was also found that an aposymbiotic alga can synthesize the unique marine sterols gorgosterol and 23-desmethylgorgosterol. Most of the sterols were identified by using mass spectroscopy and 360-MHz proton magnetic resonance. Spectroscopic data are reported for four novel sterols-(23,24R)-dimethyl-5alpha-cholest-(22E)-en-3beta-o l, 23-methyl-5alpha-cholest-22E-en-3beta-ol, cholesta-5,14-dien-3beta-ol, and 4alpha-methyl-5alpha-cholesta-8(14)-24-dien-3beta-ol.

Physiological responses to copper in giant clams: a comparison of two methods in revealing effects on photosynthesis in zooxanthellae.

PubMed

Elfwing, Tina; Blidberg, Eva; Tedengren, Michael

2002-08-01

In the present work physiological responses to a short term, sub-lethal exposure to copper (5 microg Cu2 l(-1) were studied on two species of giant clams, Tridacna gigas and Hippopus hippopus. All giant clams (fam. Tridacnidae) maintain a symbiotic relationship with photo-synthesising microalgae (zooxanthellae) and the phytotoxic effects of this copper concentration were approached with two different end points: changes in oxygen production and maximal quantum yield (Fv/Fm). Additionally we measured respiration, whereby Pg:R ratios could be calculated for the system (algae and clam) and used as an indicator of stress. Cu accumulation was only determined for T. gigas and showed significantly higher tissue concentrations in exposed specimens (11.3 microg Cu g(-1) dry wt) compared to the controls (4.2 microg Cu g(-1)). Both species displayed significantly reduced Pg:R ratios due to exposure, mainly explained by lowered gross production. No indication of stress was shown in the fluorescence measurements and possible explanations are discussed in the paper. We propose that inhibitions in the slow kinetics of photosynthesis were not captured by this fluorescence parameter. Accordingly we suggest that measurements of maximum fluorescence yield should be accompanied by complementary parameters when studying pollutants with unclear phytotoxic mechanisms.

Characterization and function of carbonic anhydrases in the zooxanthellae-giant clam symbiosis.

PubMed

Baillie, B K; Yellowlees, D

1998-03-22

Carbonic anhydrase (CA) has been purified from the host tissue of Tridacna gigas, a clam that lives in symbiosis with the dinoflagellate alga, Symbiodinium. At least two isoforms of CA were identified in both gill and mantle tissue. The larger (70 kDa) isoform is a glycoprotein with both N- and O-glycans attached and has highest homology to CAII. It is associated with the membrane fraction while the smaller (32 kDa) is present in the aqueous phase in both tissues. The 32 kDa CA has high homology with mammalian CAI at the N-terminus. Both isoforms cross-reacted with antibodies to CAII from chicken. Immunohistology demonstrated that the 70 kDa CA is present within the ciliated branchial filaments and cells lining the tertiary water channels in the gills of T. gigas. This is consistent with a role in the transport of inorganic carbon (Ci) to the haemolymph and therefore supply of Ci to the zooxanthellae. CA was also detected in mantle epithelial cells where it may also contribute to Ci supply to the zooxanthellae. The hyaline body and nerve tissue in the mantle express the 70 kDa CA where it may be involved in light sensing and nervous transmission.

Automatic Identification Technology: Tracking Weapons and Ammunition for the Norwegian Armed Forces

DTIC Science & Technology

2011-06-01

and their error rate. It can also add an anti - theft feature that provides an extra service to the launderers.35 Firms that have problems with...33  Figure 15.  Handheld 2D Matrix Reader with USB and Bluetooth Connections. .............34  Figure 16.  NDLO is...CCD Charge Coupled Device DoD United States Department of Defense EPC Electronic Product Code ERP Enterprise Resource Planning GHz Giga

Environmental Assessment for Ongoing and Future Operations at U.S. Navy Dabob Bay and Hood Canal Military Operating Areas

DTIC Science & Technology

2002-05-01

well as being cultivated in aquaculture operations in Puget Sound, including Hood Canal and Dabob Bay (Figure 3.4-2). Pacific oysters (Crassostrea...gigas) are widely cultivated in aquaculture operations in Puget Sound. Commercial oyster beds exist in Dabob Bay, mostly at the north end. Dabob Bay... Ecotoxicology of metals in aquatic sediments: binding and release, bioavailability, risk assessment, and remediation. Canadian Journal of

Giga-Hertz Electromagnetic Wave Science and Devices for Advanced Battlefield Communications

DTIC Science & Technology

2010-12-15

Yeal Song, Lei Lu , Zihui Wang, Yiyan Sun, and Joshua Bevivino, Seminar in the Department of Electrical and Computer Engineering, the University of...Celinski, “Spin wave resonance excitation in ferromagnetic films using planar waveguide structures”, J. Appl. Phys. 108, 023907 (2010) 6. Zihui ...Young-Yeal Song, Yiyan Sun, Lei Lu , Joshua Bevivino, and Mingzhong Wu, Appl. Phys. Lett. 97, 173502 (2010). 12. “Electric-field control of ferromagnetic

Dataflow-Based Implementation of Layered Sensing Applications on High-Performance Embedded Processors

DTIC Science & Technology

2013-03-01

time (milliseconds) GFlops Comparison to GPU peak performance (%) Cascade Gaussian Filtering 13 45.19 6.3 Difference of Gaussian 0.512 152...values for the GPU-targeted actor implementations in terms of Giga Floating Point Operations Per Second ( GFLOPS ). Our GFLOPS calculation for an actor...kernels. The results for GFLOPS are provided in Table . The actors were implemented on an NVIDIA GTX260 GPU, which provides 715 GFLOPS as peak

GigaUnit Transplant System: A New Mechanical Tool for Transplanting Submerged Aquatic Vegetation

DTIC Science & Technology

2008-09-01

seagrasses Halodule wrightii and Thalassia testudinum in Sarasota Bay, Florida (Uhrin et al. 2008). Information on operational capabilities and limitations...within the operational limits of the GUTS, and b) a minimum of 50-percent cover by the seagrass Halodule wrightii or Thalassia testudinum was present... Thalassia testudinum prior to transplant. (Photo courtesy of FWC.) Figure 3. A survey post marks the center of a H. wrightii planting unit (Photo

Microwave Photonic Architecture for Direction Finding of LPI Emitters: Front End Analog Circuit Design and Component Characterization

DTIC Science & Technology

2016-09-01

design to control the phase shifters was complex, and the calibration process was time consuming. During the redesign process, we carried out...signals in time domain with a maximum sampling frequency of 20 Giga samples per second. In the previous tests of the design , the performance of...PHOTONIC ARCHITECTURE FOR DIRECTION FINDING OF LPI EMITTERS: FRONT-END ANALOG CIRCUIT DESIGN AND COMPONENT CHARACTERIZATION by Chew K. Tan

Iodothyronine deiodinase gene analysis of the Pacific oyster Crassostrea gigas reveals possible conservation of thyroid hormone feedback regulation mechanism in mollusks

NASA Astrophysics Data System (ADS)

Huang, Wen; Xu, Fei; Qu, Tao; Li, Li; Que, Huayong; Zhang, Guofan

2015-07-01

Iodothyronine deiodinase catalyzes the initiation and termination of thyroid hormones (THs) effects, and plays a central role in the regulation of thyroid hormone level in vertebrates. In non-chordate invertebrates, only one deiodinase has been identified in the scallop Chlamys farreri. Here, two deiodinases were cloned in the Pacific oyster Crassostrea gigas ( CgDx and CgDy). The characteristic in-frame TGA codons and selenocysteine insertion sequence elements in the oyster deiodinase cDNAs supported the activity of them. Furthermore, seven orthologs of deiodinases were found by a tblastn search in the mollusk Lottia gigantea and the annelid Capitella teleta. A phylogenetic analysis revealed that the deiodinase gene originated from an common ancestor and a clade-specific gene duplication occurred independently during the differentiation of the mollusk, annelid, and vertebrate lineages. The distinct spatiotemporal expression patterns implied functional divergence of the two deiodinases. The expression of CgDx and CgDy was influenced by L-thyroxine T4, and putative thyroid hormone responsive elements were found in their promoters, which suggested that the oyster deiodinases were feedback regulated by TH. Epinephrine stimulated the expression level of CgDx and CgDy, suggesting an interaction effect between different hormones. This study provides the first evidence for the existence of a conserved TH feedback regulation mechanism in mollusks, providing insights into TH evolution.

Abundance and sexual size dimorphism of the giant gartersnake (Thamnophis gigas) in the Sacramento valley of California

USGS Publications Warehouse

Wylie, G.D.; Casazza, Michael L.; Gregory, C.J.; Halstead, B.J.

2010-01-01

The Giant Gartersnake (Thamnophis gigas) is restricted to wetlands of the Central Valley of California. Because of wetland loss in this region, the Giant Gartersnake is both federally and state listed as threatened. We conducted markrecapture studies of four populations of the Giant Gartersnake in the Sacramento Valley (northern Central Valley), California, to obtain baseline data on abundance and density to assist in recovery planning for this species. We sampled habitats that ranged from natural, unmanaged marsh to constructed managed marshes and habitats associated with rice agriculture. Giant Gartersnake density in a natural wetland (1.90 individuals/ha) was an order of magnitude greater than in a managed wetland subject to active season drying (0.17 individuals/ha). Sex ratios at all sites were not different from 1 1, and females were longer and heavier than males. Females had greater body condition than males, and individuals at the least disturbed sites had significantly greater body condition than individuals at the managed wetland. The few remaining natural wetlands in the Central Valley are important, productive habitat for the Giant Gartersnake, and should be conserved and protected. Wetlands constructed and restored for the Giant Gartersnake should be modeled after the permanent, shallow wetlands representative of historic Giant Gartersnake habitat. ?? 2010 Society for the Study of Amphibians and Reptiles.

The influence of ph and waterborne metals on egg fertilization of the blue mussel (Mytilus edulis), the oyster (Crassostrea gigas) and the sea urchin (Paracentrotus lividus).

PubMed

Riba, Inmaculada; Gabrielyan, Bardukh; Khosrovyan, Alla; Luque, Angel; Del Valls, T Angel

2016-07-01

This study evaluated the combined effect of pH and metals on the egg fertilization process of two estuarine species, the blue mussel (Mytilus edulis), the oyster (Crassostrea gigas) and a marine species, the sea urchin (Paracentrotus lividus). The success of egg fertilization was examined after exposure of gametes to sediment extracts of various degrees of contamination at pH 6.0, 6.5, 7.0, 7.5 and 8.0. At the pH levels from 6.5 to 8.0, the egg fertilization of the different species demonstrated different sensitivity to metal and/or acidic exposure. In all species, the results revealed that egg fertilization was almost completely inhibited at pH 6.0. The egg fertilization of the blue mussel M. edulis was the least sensitive to the exposure while that of the sea urchin P. lividus demonstrated a concentration-dependent response to the pH levels from 6.5 to 8.0. The results of this study revealed that acidity increased the concentration of several metal ions (Cr, Ni, Cu, Zn, Cd, and Pb) but reduced its availability to the organisms, probably related to the reactivity of the ions with most non-metals or to the competition among metals and other waterborne constituents.

Toward giga-pixel nanoscopy on a chip: a computational wide-field look at the nano-scale without the use of lenses

PubMed Central

McLeod, Euan; Luo, Wei; Mudanyali, Onur; Greenbaum, Alon

2013-01-01

The development of lensfree on-chip microscopy in the past decade has opened up various new possibilities for biomedical imaging across ultra-large fields of view using compact, portable, and cost-effective devices. However, until recently, its ability to resolve fine features and detect ultra-small particles has not rivalled the capabilities of the more expensive and bulky laboratory-grade optical microscopes. In this Frontier Review, we highlight the developments over the last two years that have enabled computational lensfree holographic on-chip microscopy to compete with and, in some cases, surpass conventional bright-field microscopy in its ability to image nano-scale objects across large fields of view, yielding giga-pixel phase and amplitude images. Lensfree microscopy has now achieved a numerical aperture as high as 0.92, with a spatial resolution as small as 225 nm across a large field of view e.g., >20 mm2. Furthermore, the combination of lensfree microscopy with self-assembled nanolenses, forming nano-catenoid minimal surfaces around individual nanoparticles has boosted the image contrast to levels high enough to permit bright-field imaging of individual particles smaller than 100 nm. These capabilities support a number of new applications, including, for example, the detection and sizing of individual virus particles using field-portable computational on-chip microscopes. PMID:23592185

Microflora in the Soft Tissue of the Pacific Oyster Crassostrea gigas Exposed to the Harmful Microalga Heterosigma akashiwo.

PubMed

Takenaka, Shinkuro; Yoshikawa, Takeshi; Kadowaki, Shusaku; Okunishi, Suguru; Maeda, Hiroto

2017-01-01

　A marine raphidophyte Heterosigma akashiwo is a causative agent of harmful microalgal blooms, which often cause the massive mortality of aquacultured finfish. In the present study, the Pacific oyster Crassostrea gigas was reared with H. akashiwo, and effect of the microalga on filter-feeding behavior and microflora of the gastrointestinal tract was investigated. The intake of the raphidophyte cells inhibited the molluscan filter-feeding activities, suggesting the negative physiological effect of the microalgal cell contents. However, the bivalves ingested the H. akashiwo cells to the same extent as the diatom Chaetoceros calcitrans, a non-harmful indicator to estimate the filtration rate, showing a continuation of their non-selective ingestion of the phytoplankton. Microflora of the oyster soft tissue was dominated by bacteria affiliated with the family Rhodobacteraceae, some of which are associated with microalgae. In addition, the Bacteroidetes species, in which algicidal bacteria are included, were also found in the bivalve individuals exposed to H. akashiwo. These results suggested that the ingested phytoplankton affected the microbial flora in the gastrointestinal tracts, some constituents of which helped the mollusc assimilate the ingested red tide phytoplankton. This study will provide beneficial information to clarify mechanisms by which the oyster evades the ichthyotoxicity of harmful microalgae and the participation of the intestinal microorganisms in these processes.

Cytogeography and chromosome evolution of subgenus Tridentatae of Artemisia (Asteraceae).

PubMed

McArthur, E D; Sanderson, S C

1999-12-01

The subgenus Tridentatae of Artemisia (Asteraceae: Anthemideae) is composed of 11 species of various taxonomic and geographic complexities. It is centered on Artemisia tridentata with its three widespread common subspecies and two more geographically confined ones. Meiotic chromosome counts on pollen mother cells and mitotic chromosome counts on root tips were made on 364 populations ( = 3.1 plants per population). These population counts are ∼60% of all Tridentatae counts. Some are first records for taxa. The Tridentatae are a polyploid complex (x = 9) with ploidy levels from 2x to 8x, but mostly 2x (48%) and 4x (46%). Polyploidy occurs in nine of the 11 species and in many subspecies as well. Supernumerary or b chromosomes are present only at a low frequency. In the principal species, A. tridentata, 2x plants are larger than 4x ones, which are adapted to drier conditions, probably in consequence of their slower growth rates. Gigas diploidy is a phenomenon shared by some other woody genera, but is in contrast to the gigas polyploid nature of many herbaceous genera. Polyploidy occurs within populations and is essentially autoploid. Hybridization sometimes occurs at taxa interfaces in stable hybrid zones. Stable Tridentatae hybrid zones coupled with the group's inherent propensity for polyploidization has led to the establishment of a geographically and numerically large and successful complex of species.

pH controls spermatozoa motility in the Pacific oyster (Crassostrea gigas)

PubMed Central

Suquet, Marc; Malo, Florent; Queau, Isabelle; Pignet, Patricia; Ratiskol, Dominique; Le Grand, Jacqueline; Huber, Matthias; Cosson, Jacky

2018-01-01

ABSTRACT Investigating the roles of chemical factors stimulating and inhibiting sperm motility is required to understand the mechanisms of spermatozoa movement. In this study, we described the composition of the seminal fluid (osmotic pressure, pH, and ions) and investigated the roles of these factors and salinity in initiating spermatozoa movement in the Pacific oyster, Crassostrea gigas. The acidic pH of the gonad (5.82±0.22) maintained sperm in the quiescent stage and initiation of flagellar movement was triggered by a sudden increase of spermatozoa external pH (pHe) when released in seawater (SW). At pH 6.4, percentage of motile spermatozoa was three times higher when they were activated in SW containing 30 mM NH4Cl, which alkalinizes internal pH (pHi) of spermatozoa, compared to NH4Cl-free SW, revealing the role of pHi in triggering sperm movement. Percentage of motile spermatozoa activated in Na+-free artificial seawater (ASW) was highly reduced compared to ASW, suggesting that change of pHi triggering sperm motility was mediated by a Na+/H+ exchanger. Motility and swimming speed were highest in salinities between 33.8 and 42.7‰ (within a range of 0 to 50 ‰), and pH values above 7.5 (within a range of 4.5 to 9.5). PMID:29483075

Protein thermal stabilization by charged compatible solutes: Computational studies in rubredoxin from Desulfovibrio gigas.

PubMed

Micaelo, Nuno M; Victor, Bruno L; Soares, Cláudio M

2008-08-01

Molecular dynamics simulation studies of rubredoxin from Desulfovibrio gigas (RDG) were used to characterize the molecular mechanism of thermal stabilization by the compatible solute (CS) diglycerol-phospate (DGP). DGP is a negatively charged CS that accumulates under salt stress in Archaeoglobus fulgidus. Experimental results show that a 100 mM DGP solution exerts a strong protection effect in the half-life of RDG at 363 K (Lamosa et al., Appl Environ Microbiol 2000;66:1974-1979). RDG was simulated in four aqueous solutions at 300 and 363 K: pure aqueous media, 100 mM DGP, 100 mM NaCl, and 500 mM DGP. Our work shows that the 100 mM DGP solution is able to maintain the average protein structure when the temperature is increased, preventing the occurrence of large-scale deviation of a mobile loop involved in the first steps of RDG unfolding. The molecular mechanism of thermal denaturation protection by DGP seems to involve the direct interaction between the protein and the CS by hydrogen bond interactions near the mobile loop. Several clusters of DGP molecules are formed and preferentially localized at neutral electrostatic regions of the surface. The increase of DGP concentration to 500 mM did not yield better stabilization of the protein suggesting that the thermal protective role of this charged CS is achieved at low concentrations, as shown experimentally. (c) 2008 Wiley-Liss, Inc.

Decursin and decursinol from Angelica gigas inhibit the lung metastasis of murine colon carcinoma.

PubMed

Son, Seung Hwa; Park, Kwang-Kyun; Park, Sun Kyu; Kim, Young Choong; Kim, Yeong Shik; Lee, Sang-Kook; Chung, Won-Yoon

2011-07-01

The principal objective of the present study was to evaluate the antimetastatic activity of decursin and decursinol isolated from Angelica gigas. Decursin and decursinol inhibited the proliferation and invasion of CT-26 colon carcinoma cells. The expressions of matrix metalloproteinase (MMP)-2 and MMP-9 in cells and the activities in the culture medium were also reduced by decursin and decursinol treatment. In CT-26 cells, the extracellular signal-regulated kinase (ERK) inhibitor inhibited cell proliferation, invasion and MMP-9 expression, and the c-Jun N-terminal kinase (JNK) inhibitor suppressed the expression of both MMPs, as well as cell proliferation and cell invasion. The phosphatidylinositol-3 kinase (PI3K) inhibitor reduced only the expression of MMP-2. In addition, the invasion of CT-26 cells was inhibited by the treatment with anti-MMP-9 antibody, rather than anti-MMP-2 antibody. These results indicate that MMP-9 expression via ERK and JNK plays a critical role for the invasion of CT26 cells. Decursin and decursinol downregulated ERK and JNK phosphorylation. Moreover, oral administration of decursin and decursinol reduced the formation of tumor nodules in the lungs and the increase in lung weight caused by CT-26 metastases. Therefore, both decursin and decursinol may be beneficial antimetastatic agents, targeting MMPs and their upstream signaling molecules. Copyright © 2011 John Wiley & Sons, Ltd.

Anti-Brucella Antibodies in Moose (Alces alces gigas), Muskoxen (Ovibos moschatus), and Plains Bison (Bison bison bison) in Alaska, USA.

PubMed

Nymo, Ingebjørg Helena; Beckmen, Kimberlee; Godfroid, Jacques

2016-01-01

We used an indirect enzyme-linked immunosorbent assay (iELISA) and the rose bengal test (RBT) to test for anti-Brucella antibodies in moose (Alces alces gigas), muskoxen (Ovibos moschatus), and plains bison (Bison bison bison) from various game management units (GMUs) in Alaska, US, sampled from 1982 to 2010. A portion of the sera had previously been tested with the standard plate test (SPT), the buffered Brucella antigen (BBA) card test, and the card test (CARD). No antibody-positive plains bison were identified. Anti-Brucella antibodies were detected in moose (iELISA, n=4/87; RBT, n=4/87; SPT, n=4/5; BBA, n=4/4) from GMU 23 captured in 1992, 1993, and 1995 and in muskoxen (iELISA, n=4/52; RBT, n=4/52; CARD, n=4/35) from GMUs 26A and 26B captured in 2004, 2006, and 2007. A negative effect of infection on the health of individuals of these species is probable. The presence of antibody-positive animals from 1992 to 2007 suggests presence of brucellae over time. The antibody-positive animals were found in northern Alaska, an area with a historically higher prevalence of Brucella-positive caribou, and a spillover of Brucella suis biovar 4 from caribou may have occurred. Brucella suis biovar 4 causes human brucellosis, and transmission from consumption of moose and muskoxen is possible.

Biophysical studies of interaction between hydrolysable tannins isolated from Oenothera gigas and Geranium sanguineum with human serum albumin.

PubMed

Sekowski, Szymon; Ionov, Maksim; Kaszuba, Mateusz; Mavlyanov, Saidmukhtar; Bryszewska, Maria; Zamaraeva, Maria

2014-11-01

Tannins, secondary plant metabolites, possess diverse biological activities and can interact with biopolymers such as lipids or proteins. Interactions between tannins and proteins depend on the structures of both and can result in changes in protein structure and activity. Because human serum albumin is the most abundant protein in plasma and responsible for interactions with important biological compounds (e.g. bilirubin) and proper blood pressure, therefore, it is very important to investigate reactions between HSA and tannins. This paper describes the interaction between human serum albumin (HSA) and two tannins: bihexahydroxydiphenoyl-trigalloylglucose (BDTG) and 1-O-galloyl-4,6-hexahydroxydiphenoyl-β-d-glucose (OGβDG), isolated from Geranium sanguineum and Oenothera gigas leafs, respectively. Optical (spectrofluorimetric) and chiral optical (circular dichroism) methods were used in this study. Fluorescence analysis demonstrated that OGβDG quenched HSA fluorescence more strongly than BDTG. Both OGβDG and BDTG formed complexes with albumin and caused a red shift of the fluorescence spectra but did not significantly change the protein secondary structure. Our studies clearly demonstrate that the tested tannins interact very strongly with human serum albumin (quenching constant K=88,277.26±407.04 M(-1) and K=55,552.67±583.07 M(-1) respectively for OGβDG and BDTG) in a manner depending on their chemical structure. Copyright © 2014 Elsevier B.V. All rights reserved.

A Feedback Mechanism to Control Apoptosis Occurs in the Digestive Gland of the Oyster Crassostrea gigas Exposed to the Paralytic Shellfish Toxins Producer Alexandrium catenella

PubMed Central

Rolland, Jean-Luc; Medhioub, Walid; Vergnes, Agnes; Abi-khalil, Celina; Savar, Véronique; Abadie, Eric; Masseret, Estelle; Amzil, Zouher; Laabir, Mohamed

2014-01-01

To better understand the effect of Paralytic Shellfish Toxins (PSTs) accumulation in the digestive gland of the Pacific oyster, Crassostrea gigas, we experimentally exposed individual oysters for 48 h to a PSTs producer, the dinoflagellate Alexandrium catenella. In comparison to the effect of the non-toxic Alexandrium tamarense, on the eight apoptotic related genes tested, Bax and BI.1 were significantly upregulated in oysters exposed 48 h to A. catenella. Among the five detoxification related genes tested, the expression of cytochrome P450 (CYP1A) was shown to be correlated with toxin concentration in the digestive gland of oysters exposed to the toxic dinoflagellate. Beside this, we observed a significant increase in ROS production, a decrease in caspase-3/7 activity and normal percentage of apoptotic cells in this tissue. Taken together, these results suggest a feedback mechanism, which may occur in the digestive gland where BI.1 could play a key role in preventing the induction of apoptosis by PSTs. Moreover, the expression of CYP1A, Bax and BI.1 were found to be significantly correlated to the occurrence of natural toxic events, suggesting that the expression of these genes together could be used as biomarker to assess the biological responses of oysters to stress caused by PSTs. PMID:25257788

Exposure to the Neurotoxic Dinoflagellate, Alexandrium catenella, Induces Apoptosis of the Hemocytes of the Oyster, Crassostrea gigas

PubMed Central

Medhioub, Walid; Ramondenc, Simon; Vanhove, Audrey Sophie; Vergnes, Agnes; Masseret, Estelle; Savar, Veronique; Amzil, Zouher; Laabir, Mohamed; Rolland, Jean Luc

2013-01-01

This study assessed the apoptotic process occurring in the hemocytes of the Pacific oyster, Crassostrea gigas, exposed to Alexandrium catenella, a paralytic shellfish toxins (PSTs) producer. Oysters were experimentally exposed during 48 h to the toxic algae. PSTs accumulation, the expression of 12 key apoptotic-related genes, as well as the variation of the number of hemocytes in apoptosis was measured at time intervals during the experiment. Results show a significant increase of the number of hemocytes in apoptosis after 29 h of exposure. Two pro-apoptotic genes (Bax and Bax-like) implicated in the mitochondrial pathway were significantly upregulated at 21 h followed by the overexpression of two caspase executor genes (caspase-3 and caspase-7) at 29 h, suggesting that the intrinsic pathway was activated. No modulation of the expression of genes implicated in the cell signaling Fas-Associated protein with Death Domain (FADD) and initiation-phase (caspase-2) was observed, suggesting that only the extrinsic pathway was not activated. Moreover, the clear time-dependent upregulation of five (Bcl2, BI-1, IAP1, IAP7B and Hsp70) inhibitors of apoptosis-related genes associated with the return to the initial number of hemocytes in apoptosis at 48 h of exposure suggests the involvement of strong regulatory mechanisms of apoptosis occurring in the hemocytes of the Pacific oyster. PMID:24317471

Heavy metal concentrations in diploid and triploid oysters (Crassostrea gigas) from three farms on the north-central coast of Sinaloa, Mexico.

PubMed

Muñoz Sevilla, Norma Patricia; Villanueva-Fonseca, Brenda Paulina; Góngora-Gómez, Andrés Martin; García-Ulloa, Manuel; Domínguez-Orozco, Ana Laura; Ortega-Izaguirre, Rogelio; Campos Villegas, Lorena Elizabeth

2017-10-03

The concentrations of Cu, Cd, Pb, Zn, and Hg in diploid and triploid oysters from three farms (Guasave, Ahome, and Navolato) on the north-central coast of Sinaloa, Mexico, were assessed based on samples recovered during a single culture cycle 2013-2014. Metal burdens were more strongly correlated (p < 0.05) with the location of the farm than with either the ploidy or the interaction of both variables. The metal concentration ranking for oysters of both ploidies from the three farms was Zn > Cu > Cd > Pb > Hg. For all three farms, the mean concentrations of Cd and Pb in Crassostrea gigas were high, ranging from 2.52 to 7.98 μg/g wet weight for Cd and from 0.91 to 2.83 μg/g wet weight for Pb. Diploid and triploid oysters from the Guasave farm contained high levels of Cu (76.41 and 68.97 μg/g wet weight, respectively). Cu, Cd, and Zn were highly correlated (p < 0.05), and their concentrations may be influenced by agrochemical inputs. The mean levels of Cu for the Guasave farm and of Cd and Pb for all three farms exceeded permissible limits and represented a threat to human health during the sampling period (July 2014 to July 2014).

Ostreid herpesvirus type 1 replication and host response in adult Pacific oysters, Crassostrea gigas.

PubMed

Segarra, Amélie; Baillon, Laury; Tourbiez, Delphine; Benabdelmouna, Abdellah; Faury, Nicole; Bourgougnon, Nathalie; Renault, Tristan

2014-10-08

Since 2008, massive mortality outbreaks associated with OsHV-1 detection have been reported in Crassostrea gigas spat and juveniles in several countries. Nevertheless, adult oysters do not demonstrate mortality in the field related to OsHV-1 detection and were thus assumed to be more resistant to viral infection. Determining how virus and adult oyster interact is a major goal in understanding why mortality events are not reported among adult Pacific oysters. Dual transcriptomics of virus-host interactions were explored by real-time PCR in adult oysters after a virus injection. Thirty-nine viral genes and five host genes including MyD88, IFI44, IkB2, IAP and Gly were measured at 0.5, 10, 26, 72 and 144 hours post infection (hpi). No viral RNA among the 39 genes was detected at 144 hpi suggesting the adult oysters are able to inhibit viral replication. Moreover, the IAP gene (oyster gene) shows significant up-regulation in infected adults compared to control adults. This result suggests that over-expression of IAP could be a reaction to OsHV-1 infection, which may induce the apoptotic process. Apoptosis could be a main mechanism involved in disease resistance in adults. Antiviral activity of haemolymph against herpes simplex virus (HSV-1) was not significantly different between infected adults versus control.

Comparative proteome and peptidome analysis of the cephalic fluid secreted by Arapaima gigas (Teleostei: Osteoglossidae) during and outside parental care

PubMed Central

Migaud, Hervé; Doherty, Mary K.; Siwy, Justyna; Mullen, Willian; Mesquita, Pedro E. C.; Albalat, Amaya

2017-01-01

Parental investment in Arapaima gigas includes nest building and guarding, followed by a care provision when a cephalic fluid is released from the parents’ head to the offspring. This fluid has presumably important functions for the offspring but so far its composition has not been characterised. In this study the proteome and peptidome of the cephalic secretion was studied in parental and non-parental fish using capillary electrophoresis coupled to mass spectrometry (CE-MS) and GeLC-MS/MS analyses. Multiple comparisons revealed 28 peptides were significantly different between males and parental males (PC-males), 126 between females and parental females (PC-females), 51 between males and females and 9 between PC-males and PC-females. Identification revealed peptides were produced in the inner ear (pcdh15b), eyes (tetraspanin and ppp2r3a), central nervous system (otud4, ribeye a, tjp1b and syn1) among others. A total of 422 proteins were also identified and gene ontology analysis revealed 28 secreted extracellular proteins. From these, 2 hormones (prolactin and stanniocalcin) and 12 proteins associated to immunological processes (serotransferrin, α-1-antitrypsin homolog, apolipoprotein A-I, and others) were identified. This study provides novel biochemical data on the lateral line fluid which will enable future hypotheses-driven experiments to better understand the physiological roles of the lateral line in chemical communication. PMID:29065179

Cellular responses of Pacific oyster (Crassostrea gigas) gametes exposed in vitro to polystyrene nanoparticles.

PubMed

González-Fernández, Carmen; Tallec, Kevin; Le Goïc, Nelly; Lambert, Christophe; Soudant, Philippe; Huvet, Arnaud; Suquet, Marc; Berchel, Mathieu; Paul-Pont, Ika

2018-06-06

While the detection and quantification of nano-sized plastic in the environment remains a challenge, the growing number of polymer applications mean that we can expect an increase in the release of nanoplastics into the environment by indirect outputs. Today, very little is known about the impact of nano-sized plastics on marine organisms. Thus, the objective of this study was to investigate the toxicity of polystyrene nanoplastics (NPs) on oyster (Crassostrea gigas) gametes. Spermatozoa and oocytes were exposed to four NPs concentrations ranging from 0.1 to 100 mg L -1 for 1, 3 and 5 h. NPs coated with carboxylic (PS-COOH) and amine groups (PS-NH 2 ) were used to determine how surface properties influence the effects of nanoplastics. Results demonstrated the adhesion of NPs to oyster spermatozoa and oocytes as suggested by the increase of relative cell size and complexity measured by flow-cytometry and confirmed by microscopy observations. A significant increase of ROS production was observed in sperm cells upon exposure to 100 mg L -1 PS-COOH, but was not observed with PS-NH 2 , suggesting a differential effect according to the NP-associated functional group. Altogether, these results demonstrate that the effects of NPs occur rapidly, are complex and are possibly associated with the cellular eco-corona, which could modify NPs behaviour and toxicity. Copyright © 2018. Published by Elsevier Ltd.

Study of the antioxidant capacity in gills of the Pacific oyster Crassostrea gigas in link with its reproductive investment.

PubMed

Béguel, Jean-Philippe; Huvet, Arnaud; Quillien, Virgile; Lambert, Christophe; Fabioux, Caroline

2013-01-01

Energy allocation principle is a core element of life-history theory in which "the cost of reproduction" corresponds to an acceleration of senescence caused by an increase in reproductive investment. In the "theory of aging", senescence is mainly due to the degradation of lipids, proteins and DNA by reactive oxygen species (ROS), by-products of oxidative metabolism. Some studies have shown that oxidative stress susceptibility could be a cost of reproduction. The present study investigates the effect of reproductive investment on antioxidant capacity in the gills of a species with a very high reproductive investment, the Pacific oyster Crassostrea gigas. We used RNA interference targeting the oyster vasa-like gene (Oyvlg) to produce oysters with contrasted reproductive investment. Antioxidant capacity was studied by measuring the mRNA levels of genes encoding major antioxidant enzymes, and the activity of these enzymes. The highest reproductive investment was associated with the highest transcript levels for glutathione peroxidase and extra-cellular and mitochondrial superoxide dismutase. In contrast, lipid peroxidation did not show any sign of oxidative damage whatever the reproductive investment. Up-regulation of certain genes encoding enzymes involved in the first step of ROS detoxification could therefore be a part of the organism's strategy for managing the pro-oxidant species produced by heavy reproductive investment. Copyright © 2012 Elsevier Inc. All rights reserved.

Effects of Angelica gigas Nakai as an Anti-Inflammatory Agent in In Vitro and In Vivo Atopic Dermatitis Models

PubMed Central

Ok, Seon; Oh, Sa-Rang; Jung, Tae-Sung; Jeon, Sang-Ok; Jung, Ji-wook

2018-01-01

We investigated the cellular and molecular mechanisms mediating the effects of Angelica gigas Nakai extract (AGNE) through the mitogen-activated protein kinases (MAPKs)/NF-κB pathway using in vitro and in vivo atopic dermatitis (AD) models. We examined the effects of AGNE on the expression of proinflammatory cytokines and chemokines in human mast cell line-1 (HMC-1) cells. Compound 48/80-induced pruritus and 2,4-dinitrochlorobenzene- (DNCB-) induced AD-like skin lesion mouse models were also used to investigate the antiallergic effects of AGNE. AGNE reduced histamine secretion, production of proinflammatory cytokines including interleukin- (IL-) 1β, IL-4, IL-6, IL-8, and IL-10, and expression of cyclooxygenase- (COX-) 2 in HMC-1 cells. Scratching behavior and DNCB-induced AD-like skin lesions were also attenuated by AGNE administration through the reduction of serum IgE, histamine, tumor necrosis factor-α (TNF-α), IL-6 levels, and COX-2 expression in skin tissue from mouse models. Furthermore, these inhibitory effects were mediated by the blockade of the MAPKs and NF-κB pathway. The findings of this study proved that AGNE improves the scratching behavior and atopy symptoms and reduces the activity of various atopy-related mediators in HMC-1 cells and mice model. These results suggest the AGNE has a therapeutic potential in anti-AD. PMID:29713361

Ostreid herpesvirus OsHV-1 μVar in Pacific oysters Crassostrea gigas (Thunberg 1793) of the Wadden Sea, a UNESCO world heritage site.

PubMed

Gittenberger, A; Voorbergen-Laarman, M A; Engelsma, M Y

2016-01-01

The Wadden Sea is an extensive wetland area, recognized as UNESCO world heritage site of international importance. Since the mid-1990s, the invasive Pacific oyster Crassostrea gigas (Thunberg 1793) population in the area has grown exponentially, having a distinct impact on the ecosystem. The recent spread of the emerging oyster pathogen Ostreid herpesvirus OsHV-1 μVar worldwide and specifically in the oyster culture areas in the south of the Netherlands raised the question whether the virus may also be present in the Wadden Sea. In the summer of 2012 juvenile Pacific oysters were collected from five locations in the Dutch Wadden Sea. The virus was shown to be present in three of the five locations by real-time PCR and sequencing. It was concluded that OsHV-1 μVar has settled itself in Pacific oyster reefs in the Wadden Sea. These results and the recent discoveries of OsHV-1 microvariants in Australia and Korea indicate that OsHV-1 μVar and related variants might be more widespread than can be deduced from current literature. In particular in regions with no commercial oyster culture, similar to the Wadden Sea, the virus may go undetected as wild beds with mixed age classes hamper the detection of mortality among juvenile oysters. © 2015 John Wiley & Sons Ltd.

Field chronobiology of a molluscan bivalve: how the moon and sun cycles interact to drive oyster activity rhythms.

PubMed

Tran, Damien; Nadau, Arnaud; Durrieu, Gilles; Ciret, Pierre; Parisot, Jean-Paul; Massabuau, Jean-Charles

2011-05-01

The present study reports new insights into the complexity of environmental drivers in aquatic animals. The focus of this study was to determine the main forces that drive mollusc bivalve behavior in situ. To answer this question, the authors continuously studied the valve movements of permanently immersed oysters, Crassostrea gigas, during a 1-year-long in situ study. Valve behavior was monitored with a specially build valvometer, which allows continuously recording of up to 16 bivalves at high frequency (10 Hz). The results highlight a strong relationship between the rhythms of valve behavior and the complex association of the sun-earth-moon orbital positions. Permanently immersed C. gigas follows a robust and strong behavior primarily driven by the tidal cycle. The intensity of this tidal driving force is modulated by the neap-spring tides (i.e., synodic moon cycle), which themselves depend of the earth-moon distance (i.e., anomalistic moon cycle). Light is a significant driver of the oysters' biological rhythm, although its power is limited by the tides, which remain the predominant driver. More globally, depending where in the world the bivalves reside, the results suggest their biological rhythms should vary according to the relative importance of the solar cycle and different lunar cycles associated with tide generation. These results highlight the high plasticity of these oysters to adapt to their changing environment.

Diet induced differences in carbon isotope fractionation between sirenians and terrestrial ungulates

USGS Publications Warehouse

Clementz, M.T.; Koch, P.L.; Beck, C.A.

2007-01-01

Carbon isotope differences (??13C) between bioapatite and diet, collagen and diet, and bioapatite and collagen were calculated for four species of sirenians, Dugong dugon (Mu??ller), Trichechus manatus (Linnaeus), Trichechus inunguis (Natterer), and the extinct Hydrodamalis gigas (Zimmerman). Bone and tooth samples were taken from archived materials collected from populations during the mid eighteenth century (H. gigas), between 1978 and 1984 (T. manatus, T. inunguis), and between 1997 and 1999 (D. dugon). Mean ??13C values were compared with those for terrestrial ungulates, carnivores, and six species of carnivorous marine mammals (cetaceans = 1; pinnipeds = 4; mustelids = 1). Significant differences in mean ??13C values among species for all tissue types were detected that separated species or populations foraging on freshwater plants or attached marine macroalgae (??13C values -4???; ??13Cbioapatite-diet ???11???). Likewise, ??13Cbioapatite-collagen values for freshwater and algal-foraging species (???7???) were greater than those for seagrass-foraging species (???5???). Variation in ??13C values calculated between tissues and between tissues and diet among species may relate to the nutritional composition of a species' diet and the extent and type of microbial fermentation that occurs during digestion of different types of plants. These results highlight the complications that can arise when making dietary interpretations without having first determined species-specific ??13Ctissue-diet values. ?? 2007 Springer-Verlag.

Toward giga-pixel nanoscopy on a chip: a computational wide-field look at the nano-scale without the use of lenses.

PubMed

McLeod, Euan; Luo, Wei; Mudanyali, Onur; Greenbaum, Alon; Ozcan, Aydogan

2013-06-07

The development of lensfree on-chip microscopy in the past decade has opened up various new possibilities for biomedical imaging across ultra-large fields of view using compact, portable, and cost-effective devices. However, until recently, its ability to resolve fine features and detect ultra-small particles has not rivalled the capabilities of the more expensive and bulky laboratory-grade optical microscopes. In this Frontier Review, we highlight the developments over the last two years that have enabled computational lensfree holographic on-chip microscopy to compete with and, in some cases, surpass conventional bright-field microscopy in its ability to image nano-scale objects across large fields of view, yielding giga-pixel phase and amplitude images. Lensfree microscopy has now achieved a numerical aperture as high as 0.92, with a spatial resolution as small as 225 nm across a large field of view e.g., >20 mm(2). Furthermore, the combination of lensfree microscopy with self-assembled nanolenses, forming nano-catenoid minimal surfaces around individual nanoparticles has boosted the image contrast to levels high enough to permit bright-field imaging of individual particles smaller than 100 nm. These capabilities support a number of new applications, including, for example, the detection and sizing of individual virus particles using field-portable computational on-chip microscopes.

Allozyme electrophoresis as a tool for distinguishing different zooxanthellae symbiotic with giant clams

PubMed Central

Baillie, B. K.; Monje, V.; Silvestre, V.; Sison, M.; Belda-Baillie, C. A.

1998-01-01

The taxonomy of zooxanthellae in marine invertebrate symbioses is not well understood owing mainly to their lack of reliable morphological differences. Nevertheless, previous work using protein and DNA electrophoreses has set the stage for advancing our taxonomic understanding of cnidarian zooxanthellae. Here we present the use of allozymes as genetic markers for distinguishing algal isolates from tridacnid hosts. Zooxanthellae from seven Tridacna and Hippopus species were isolated and maintained in axenic clonal cultures over many generations. Of 16 enzyme systems, α- and β-esterase (EST), esterase-F (EST-F), glucose phosphate isomerase (GPI), and malate dehydrogenase (MDH) were found suitable polymorphic markers of genetic differences among clonal cultures. Of 39 clonal isolates, 97% were found to be genetically distinguishable. This high extent of genetic variation in zooxanthellae within and between clam species was unexpected, and is difficult to explain based solely on the general notion of asexual reproduction in symbiotic zooxanthellae. Our results are also consistent with the occurrence of sexual reproduction in clam zooxanthellae. The close genetic similarity of the symbionts of Tridacna gigas, the largest and fastest-growing clam species, and the difficulty of initiating their clonal cultures in the given nutrient medium, compared with the symbionts of other clam species, are further indicative of possibly distinct algal symbionts in T. gigas. These findings are discussed in light of current taxonomic understanding of these organisms.

One GigaSample Per Second Data Acquisition using Available Gate Array Technology

NASA Technical Reports Server (NTRS)

Wagner, K.W.

1999-01-01

A new National Aeronautics and Space Administration instrument forced demanding requirements upon its altimeter digitizer system. Eight-bit data would be generated at a rate of one billion samples per second. NASA had never before attempted to capture such high-speed data in the radiation, low-power, no-convective-cooling, limited-board-area environment of space. This presentation describes how the gate array technology available at the time of the design was used to implement this one gigasample per second data acquisition system

Pan-STARRRS Status and Geo Observations Results

DTIC Science & Technology

2011-09-01

Earth Orbiting asteroids which may pose a threat. The final design includes four 1.8m telescopes each equipped with a giga- pixel camera and is...are relative to the rotation of the earth, the mount is commanded utilizing “stare mode” for all GEO observations. The belt is surveyed by...integration time the geo belt is observed M number of times. In order to detect an object it must be observed N number of times out of the possible M

Characteristics of switching plasma in an inverse-pinch switch

NASA Technical Reports Server (NTRS)

Lee, Ja H.; Choi, Sang H.; Venable, Demetrius D.; Han, Kwang S.; Nam, Sang H.

1993-01-01

Characteristics of the plasma that switches on tens of giga volt-ampere in an inverse-pinch plasma switch (INPIStron) have been made. Through optical and spectroscopic diagnostics of the current carrying plasma, the current density, the motion of current paths, dominant ionic species have been determined in order to access their effects on circuit parameters and material erosion. Also the optimum operational condition of the plasma-puff triggering method required for azimuthally uniform conduction in the INPIStron has been determined.

The giga-CMD of the VVV survey

NASA Astrophysics Data System (ADS)

Alonso-García, J.; Gonzalez, O. A.; Hempel, M.; Minniti, D.; Pullen, P.; Saito, R. K.; Valenti, E.; Zoccali, M.

2017-07-01

The VISTA Variables in the Vía Láctea (VVV) survey has changed our picture of the inner Galaxy in the last years. Using the near-infrared images VVV provides, we have been able to build deep and homogenous color-magnitude diagrams (CMDs) of the bulge and inner disk of the Milky Way, which contain around one billion sources. We are using these CMDs to learn about the physical parameters and structure of the central regions of our Galaxy, along with the extinction towards them.

A 1 GHz sample rate, 256-channel, 1-bit quantization, CMOS, digital correlator chip

NASA Technical Reports Server (NTRS)

Timoc, C.; Tran, T.; Wongso, J.

1992-01-01

This paper describes the development of a digital correlator chip with the following features: 1 Giga-sample/second; 256 channels; 1-bit quantization; 32-bit counters providing up to 4 seconds integration time at 1 GHz; and very low power dissipation per channel. The improvements in the performance-to-cost ratio of the digital correlator chip are achieved with a combination of systolic architecture, novel pipelined differential logic circuits, and standard 1.0 micron CMOS process.

Investigation of Coding Techniques for Memory and Delay Efficient Interleaving in Slow Rayleigh Fading

DTIC Science & Technology

1991-11-01

2 mega joule/m 2 (MJ/m 2 ) curie 3.700000 x E +1 *giga becquerel (GBq) degree (angle) 1.745329 x E -2 radian (rad) degree Farenheit tK = (tp...quantization assigned two quantization values. One value was assigned for demodulation values that was larger than zero and another quantization value to...demodulation values that were smaller than zero (for maximum-likelihood decisions). Logic 0 was assigned for a positive demodulation value and a logic 1 was

Design and Construction of a High-speed Network Connecting All the Protein Crystallography Beamlines at the Photon Factory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsugaki, Naohiro; Yamada, Yusuke; Igarashi, Noriyuki

2007-01-19

A private network, physically separated from the facility network, was designed and constructed which covered all the four protein crystallography beamlines at the Photon Factory (PF) and Structural Biology Research Center (SBRC). Connecting all the beamlines in the same network allows for simple authentication and a common working environment for a user who uses multiple beamlines. Giga-bit Ethernet wire-speed was achieved for the communication among the beamlines and SBRC buildings.

A preliminary investigation of the variables affecting the distribution of giant gartersnakes (Thamnophis gigas) in the Sacramento Valley, California

USGS Publications Warehouse

Halstead, Brian J.; Skalos, Shannon M.; Casazza, Michael L.; Wylie, Glenn D.

2015-09-30

Giant gartersnakes (Thamnophis gigas) comprise a species of rare, semi-aquatic snake precinctive to the Central Valley of California. Because of the loss of more than 90% of their natural habitat, giant gartersnakes are listed as Threatened by the United States and California endangered species acts. Little is known, however, about the distribution of giant gartersnakes in the Sacramento Valley, which is where most extant populations occur. We conducted detection-nondetection surveys for giant gartersnakes throughout the rice-growing regions of the Sacramento Valley, and used occupancy models to examine evidence for the effects of landscape-scale GIS-derived variables, local habitat and vegetation composition, and prey communities on patterns of giant gartersnake occurrence. Although our results are based on a relatively small sample of sites, we found that distance to historic marsh, relative fish count, and an interaction of distance to historic marsh with proportion of habitat composed of submerged vegetation were important variables for explaining occupancy of giant gartersnakes. In particular, giant gartersnakes were more likely to occur closer to historic marsh and where relatively fewer fish were captured in traps. At locations in or near historic marsh, giant gartersnakes were more likely to occur in areas with less submerged vegetation, but this relationship was reversed (and more uncertain) at sites distant from historic marsh. Additional research with a larger sample of sites would further elucidate the distribution of giant gartersnakes in the Sacramento Valley.

Studies on omnidirectional enhancement of giga-hertz radiation by sub-wavelength plasma modulation

NASA Astrophysics Data System (ADS)

Fanrong, KONG; Qiuyue, NIE; Shu, LIN; Zhibin, WANG; Bowen, LI; Shulei, ZHENG; Binhao, JIANG

2018-01-01

The technology of radio frequency (RF) radiation intensification for radio compact antennas based on modulation and enhancement effects of sub-wavelength plasma structures represents an innovative developing strategy. It exhibits important scientific significance and promising potential of broad applications in various areas of national strategic demands, such as electrical information network and microwave communication, detection and control technology. In this paper, laboratory experiments and corresponding analyses have been carried out to investigate the modulation and enhancement technology of sub-wavelength plasma structure on the RF electromagnetic radiation. An application focused sub-wavelength plasma-added intensification up to ∼7 dB higher than the free-space radiation is observed experimentally in giga-hertz (GHz) RF band. The effective radiation enhancement bandwidth covers from 0.85 to 1.17 GHz, while the enhanced electromagnetic signals transmitted by sub-wavelength plasma structures maintain good communication quality. Particularly, differing from the traditional RF electromagnetic radiation enhancement method characterized by focusing the radiation field of antenna in a specific direction, the sub-wavelength plasma-added intensification of the antenna radiation presents an omnidirectional enhancement, which is reported experimentally for the first time. Corresponding performance characteristics and enhancement mechanism analyses are also conducted in this paper. The results have demonstrated the feasibility and promising potential of sub-wavelength plasma modulation in application focused RF communication, and provided the scientific basis for further research and development of sub-wavelength plasma enhanced compact antennas with wide-range requests and good quality for communication.

Pesticide residues, heavy metals, and DNA damage in sentinel oysters Crassostrea gigas from Sinaloa and Sonora, Mexico.

PubMed

Vázquez-Boucard, Celia; Anguiano-Vega, Gerardo; Mercier, Laurence; Rojas del Castillo, Emilio

2014-01-01

Pesticides and heavy metals were analyzed in sentinel Crassostrea gigas oysters placed in six aquaculture sites close to a contaminated agricultural region. Each site was sampled twice. Tests revealed the presence of organochlorine (OC) pesticides in the oysters at concentrations varying from 31.8 to 72.5 μg/kg for gamma-hexachlorocyclohexane (γ-HCH); from 1.2 to 3.1 μg/kg for dichlorodiphenyldichloroethylene (4,4-DDE); from 1.6 to 2.3 μg/kg for endosulfan I; and from 1.4 to 41.2 μg/kg for endosulfan II, as well as heavy metals in concentrations that exceeded Mexican tolerance levels (405.5 to 987.8 μg/g for zinc; 4.2 to 7.3 μg/g for cadmium; and 7.2 to 9.9 μg/g for lead). Significant levels of DNA damage in oyster hemocytes were also detected. There was a significant, positive correlation between genotoxic damage and concentration of nickel or the presence of endosulfan II. Cellular viability evaluated by cytotoxic analyses was found to be high at 80%. Marked inhibition in activity of acetylcholinesterase (AChE ) and induction of glutathione S-transferase (GST) activity was noted. Data demonstrated a significant relation between AChE activity inhibition and presence of endosulfan II, γ-HCH, copper, lead, and 4,4-DDE, as well as between AChE and GST activity at different sites.

Omega-3 fatty acids incorporated colloidal systems for the delivery of Angelica gigas Nakai extract.

PubMed

Lee, Jeong-Jun; Park, Ju-Hwan; Lee, Jae-Young; Jeong, Jae Young; Lee, Song Yi; Yoon, In-Soo; Kang, Wie-Soo; Kim, Dae-Duk; Cho, Hyun-Jong

2016-04-01

Omega-3 (ω-3) fish oil-enriched colloidal systems were developed for the oral delivery of Angelica gigas Nakai (AGN) extract (ext). By constructing a pseudo-ternary phase diagram, the composition of oil-in-water (o/w) microemulsion (ME) systems based on ω-3 (oil), Labrasol (surfactant), and water was determined. AGN ext was dissolved into the ME system and d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) was added to the ME formulation in order to enhance the mucosal absorption of the pharmacologically active ingredients in the AGN ext. The droplet size of AGN-loaded MEs was 205-277 nm and their morphology was spherical. The release of major components of AGN, decursin (D) and decursinol angelate (DA), from ME formulations in pH 1.2 and 6.8 buffers was significantly greater (P<0.05) than that from the AGN suspension group. The pharmacokinetic properties of AGN-loaded MEs in rats were evaluated by measuring decursinol (DOH) concentrations in plasma after oral administration. TPGS-included ME (F2) resulted in significantly greater (P<0.05) systemic exposure of DOH than that with ME without TPGS (F1), AGN ext+TPGS, and AGN in suspension. Severe toxicity of F1 and F2 on the intestinal epithelium was not observed by histological staining. The colloidal carriers described herein are promising delivery systems for oral administration of AGN ext. Copyright © 2015 Elsevier B.V. All rights reserved.

Protective effect of decursin and decursinol angelate-rich Angelica gigas Nakai extract on dextran sulfate sodium-induced murine ulcerative colitis.

PubMed

Oh, Sa-Rang; Ok, Seon; Jung, Tae-Sung; Jeon, Sang-Ok; Park, Ji-Min; Jung, Ji-Wook; Ryu, Deok-Seon

2017-09-01

To investigate the anti-inflammatory effects of decursin and decursinol angelate-rich Angelica gigas Nakai (AGNE) on dextran sulfate sodium (DSS)-induced murine ulcerative colitis (UC). The therapeutic effect of an AGNE was analyzed in a mouse model of UC induced by DSS. Disease activity index values were measured by clinical signs such as a weight loss, stool consistency, rectal bleeding and colon length. A histological analysis was performed using hematoxylin and eosin staining. Key inflammatory cytokines and mediators including IL-6, TNF-α, PGE 2 , COX-2 and HIF-1α were assayed by enzyme-linked immunosorbent assay or western blotting. Treatment with the AGNE at 10, 20, and 40 mg/kg alleviated weight loss, decreased disease activity index scores, and reduced colon shortening in mice with DSS-induced UC. AGNE inhibited the production of IL-6 and TNF-α in serum and colon tissue. Moreover, AGNE suppressed the increased expression of COX-2 and HIF-1α and the increased production of PGE 2 in colon tissue were observed in mice with DSS-induced UC. Additionally, histological damage was also alleviated by AGNE treatment. The findings of this study verified that AGNE significantly improves clinical symptoms and reduces the activity of various inflammatory mediators. These results indicate the AGNE has the therapeutic potential in mice with DSS-induced UC. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

Potent inhibition of monoamine oxidase A by decursin from Angelica gigas Nakai and by wogonin from Scutellaria baicalensis Georgi.

PubMed

Lee, Hyun Woo; Ryu, Hyung Won; Kang, Myung-Gyun; Park, Daeui; Lee, Hanna; Shin, Heung Mook; Oh, Sei-Ryang; Kim, Hoon

2017-04-01

During the ongoing search for new monoamine oxidase (MAO) inhibitors, five coumarin derivatives and eight flavonoids were isolated from the roots of Angelica gigas Nakai and Scutellaria baicalensis Georgi, respectively. Of the phytochemicals, decursin (4) was found to potently and selectively inhibit human MAO-A (IC 50 =1.89μM). The IC 50 value of 4 for MAO-A belonged to the lowest group in herbal sources and was similar to that of toloxatone (1.78μM), a marketed drug. Wogonin (11) effectively inhibited MAO-A and MAO-B (IC 50 =6.35 and 20.8μM, respectively). Furthermore, compounds 5 (decursinol angelate) and 10 (baicalein) were observed to selectively and moderately inhibit MAO-A. In addition, compound 4 reversibly and competitively inhibited MAO-A with a K i of 0.17μM. Compound 11 also competitively inhibited MAO-A and MAO-B (K i =0.56 and 1.96μM, respectively). Molecular docking simulation revealed that 4 interacts with Asn181 residue of MAO-A or Asn116 residue of MAO-B by formation of hydrogen bond. The findings suggest compounds 4 and 11 be considered as new potent and reversible MAO-A inhibitors or useful lead compounds for the developments of MAO inhibitors for the treatment of disorders like depression, Parkinson's disease and Alzheimer disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Simultaneous Determination of Decursin, Decursinol Angelate, Nodakenin, and Decursinol of Angelica gigas Nakai in Human Plasma by UHPLC-MS/MS: Application to Pharmacokinetic Study.

PubMed

Kim, Sook-Jin; Ko, Se-Mi; Choi, Eun-Jeong; Ham, Seong-Ho; Kwon, Young-Dal; Lee, Yong-Bok; Cho, Hea-Young

2018-04-26

Coumarins in Cham-dang-gwi, the dried root of Angelica gigas Nakai (AGN), possess pharmacological effects on anemia, pain, infection, and articular rheumatism. The AGN root containes decursin (D), decursinol angelate (DA), nodakenin, and decursinol (DOH), a major metabolite of D and DA. The aim of this study was to develop a simultaneous determination method for these four coumarins in human plasma using ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Chromatographic separation was performed on dual columns (Kinetex ® C 18 column and Capcell core C 18 column) with mobile phase consisting of water and acetonitrile at a flow rate of 0.3 mL/min using gradient elution. Multiple reaction monitoring was operated in positive ion mode with precursors to product ion transition values of m / z 328.9→228.8, 328.9→228.9, 409.4→248.8, and 246.8→212.9 to measure D, DA, nodakenin, and DOH, respectively. Linear calibration curves were fitted over concentration range of 0.05⁻50 ng/mL for these four components, with correlation coefficient greater than 0.995. Inter- and intra-day accuracies were between 90.60% and 108.24%. These precisions were within 11.19% for all components. The established method was then applied to a pharmacokinetic study for the four coumarins after usual dosing in Korean subjects.

Nanocomposites based on Soluplus and Angelica gigas Nakai extract fabricated by an electrohydrodynamic method for oral administration.

PubMed

Lee, Jeong-Jun; Nam, Suyeong; Park, Ju-Hwan; Lee, Song Yi; Jeong, Jae Young; Lee, Jae-Young; Kang, Wie-Soo; Yoon, In-Soo; Kim, Dae-Duk; Cho, Hyun-Jong

2016-12-15

Nanocomposites (NCs) based on Soluplus (SP) were fabricated by an electrohydrodynamic (EHD) method for the oral delivery of Angelica gigas Nakai (AGN). Nano-sized particles were obtained after dispersing the resultant, produced by the EHD technique, in the aqueous environment. AGN/SP2 (AGN:SP=1:2, w/w) NC dispersion in aqueous media exhibited a 130nm mean diameter, narrow size distribution, and robust stability in the tested concentration range of the ethanol extract of AGN (AGN EtOH ext) and at pH 1.2 and 6.8. Amorphization of the components of AGN and their interactions with SP in the AGN/SP2 NC formulation were demonstrated by X-ray diffractometry (XRD) analysis. The released amounts of decursin (D) and decursinol angelate (DA), major components of AGN, from NCs were improved compared with those from the AGN EtOH ext group at both pH 1.2 and 6.8. As D and DA can be metabolized into decursinol (DOH) in the liver after oral administration, the DOH concentrations in plasma were quantitatively determined to evaluate the oral absorption of AGN. In a pharmacokinetic study in rats, higher oral absorption and the maximum concentration in plasma (C max ) were presented in the AGN/SP2 NC group compared with the AGN EtOH ext and AGN NC groups. These findings indicate the successful application of developed SP-based NCs for the oral delivery of AGN. Copyright © 2016 Elsevier Inc. All rights reserved.

Polydopamine-coated nanocomposites of Angelica gigas Nakai extract and their therapeutic potential for triple-negative breast cancer cells.

PubMed

Nam, Suyeong; Lee, Song Yi; Kim, Jung-Jin; Kang, Wie-Soo; Yoon, In-Soo; Cho, Hyun-Jong

2018-05-01

Polydopamine (PD)-coated nanocomposites (NCs) based on the ethanol extract of Angelica gigas Nakai (AGN EtOH ext) were fabricated and evaluated for breast cancer therapy. AGN NCs were prepared using a modified emulsification-solvent evaporation method and were further incubated in dopamine solution (at pH 8.6) to be covered with the PD layer. PD-AGN NCs with a 213-nm mean diameter, narrow size distribution, and negative zeta potential values were fabricated in this study. Less negative (close to zero) zeta potential value of PD-AGN NCs than that of AGN NCs implied the existence of the PD layer in the outer surface of NCs. The PD layer in PD-AGN NCs was also identified by X-ray photoelectron spectroscopy (XPS) and ultraviolet (UV)/visible absorption analyses. The sustained release of decursin (D) and decursinol angelate (DA), as major active pharmacological components of AGN, was observed in both AGN NCs and PD-AGN NCs. Enhanced cellular binding property of PD-AGN NCs, compared to AGN NCs, in MDA-MB-231 (human breast adenocarcinoma; triple-negative breast cancer) cells was observed. Improved anticancer activities of PD-AGN NCs compared with those of AGN EtOH ext and AGN NCs were also shown in MDA-MB-231 cells. The developed PD-AGN NCs may be used as remarkable platform nanocarriers for efficient breast cancer therapy. Copyright © 2018 Elsevier B.V. All rights reserved.

Crassostrea gigas mortality in France: the usual suspect, a herpes virus, may not be the killer in this polymicrobial opportunistic disease.

PubMed

Petton, Bruno; Bruto, Maxime; James, Adèle; Labreuche, Yannick; Alunno-Bruscia, Marianne; Le Roux, Frédérique

2015-01-01

Successive disease outbreaks in oyster (Crassostrea gigas) beds in France have resulted in dramatic losses in production, and subsequent decline in the oyster-farming industry. Deaths of juvenile oysters have been associated with the presence of a herpes virus (OsHV-1 μvar) and bacterial populations of the genus Vibrio. Although the pathogenicity of OsHV-1 μvar, as well as several strains of Vibrio has been demonstrated by experimental infections, our understanding of the complexity of infections occurring in the natural environment remains limited. In the present study, we use specific-pathogen-free (SPF) oysters infected in an estuarine environment to study the diversity and dynamics of cultured microbial populations during disease expression. We observe that rapid Vibrio colonization followed by viral replication precedes oyster death. No correlation was found between the vibrio concentration and viral load in co-infected animals. We show that the quantity of viral DNA is a predictor of mortality, however, in the absence of bacteria, a high load of herpes virus is not sufficient to induce the full expression of the disease. In addition, we demonstrate that juvenile mortalities can occur in the absence of herpes virus, indicating that the herpes virus appears neither essential nor sufficient to cause juvenile deaths; whereas bacteria are necessary for the disease. Finally, we demonstrate that oysters are a reservoir of putative pathogens, and that the geographic origin, age, and cultivation method of oysters influence disease expression.

Reconstructing an island radiation using ancient and recent DNA: the extinct and living day geckos (Phelsuma) of the Mascarene islands.

PubMed

Austin, J J; Arnold, E N; Jones, C G

2004-04-01

Mitochondrial (12SrRNA and cyt b, 1086 bp) and nuclear (c-mos, 374 bp) DNA sequences were used to investigate relationships and biogeography of 24 living and extinct taxa of Phelsuma geckos. Monophyly of Phelsuma and sister relationship to the SW African Rhoptropella is corroborated. Phelsuma originated on Madagascar and made multiple long-distance invasions of oceanic islands including the Mascarenes, Aldabra, Comores, Seychelles, Andamans, and perhaps Pemba. The Mascarenes were probably colonised once, about 4.2-5.1Ma, and here Phelsuma rosagularis and Phelsuma inexpectata are newly recognised as species, as are three lineages of Phelsuma cepediana. Mascarene relationships are: Phelsuma edwardnewtoni, Phelsuma gigas (Phelsuma guentheri ((((P. cepediana A (P. cepediana B, C)) P. rosagularis) Phelsuma borbonica) ((Phelsuma ornata, P. inexpectata) Phelsuma guimbeaui))). The two recently extinct species, P. edwardnewtoni and the giant secondarily nocturnal Phelsuma gigas, differentiated on Rodrigues while on Mauritius the large nocturnal P. guentheri separated from a small diurnal form that radiated into six species, a likely result of volcanic activity. Two small-bodied lineages from Mauritius invaded the more recent island of Réunion producing two more species. Outside the Mascarenes, two mainly Madagascan assemblages are substantiated: Phelsuma serraticauda (Phelsuma lineata, Phelsuma laticauda, Phelsuma quadriocellata); (Phelsuma m. kochi (Phelsuma m. grandis, Phelsuma abboti)) (Phelsuma astriata, Phelsuma sundbergi). Their relationships to the Mascarene clade, and to Phelsuma mutabilis, Phelsuma standingi and Phelsuma andamanensis are unresolved.

Effects of dissolved organic carbon on the toxicity of copper to the developing embryos of the Pacific oyster (Crassostrea gigas).

PubMed

Brooks, Steven J; Bolam, Thi; Tolhurst, Laura; Bassett, Janice; La Roche, Jay; Waldock, Mike; Barry, Jon; Thomas, Kevin V

2007-08-01

The effects of humic acid (HA) on copper speciation and its subsequent toxicity to the sensitive early life stages of the Pacific oyster (Crassostrea gigas) are presented. Differential pulse anodic stripping voltammetry with a hanging mercury drop electrode was used to measure the copper species as labile copper (LCu; free ion and inorganic copper complexes) and total copper (TCu) with respect to increasing HA concentration. The TCu and LCu 50% effect concentrations (EC50s) in the absence of HA were 20.77 microg/L (95% confidence interval [CI], 24.02-19.97 microg/L) and 8.05 microg/L (95% CI, 9.6-5.92 microg/L) respectively. A corrected dissolved organic carbon (DOC) concentration (HA only) of 1.02 mg/L was required to significantly increase the TCu EC50 to approximately 41.09 microg/L (95% CI, 44.27-37.52 microg/L; p < 0.05), almost doubling that recorded when DOC (as HA) was absent from the test media. In contrast, the LCu EC50 was unaffected by changes in DOC concentration and was stable throughout the corrected DOC concentration range. The absence of change in the LCu EC50, despite increased HA concentration, suggests that the LCu fraction, not TCu, was responsible for the observed toxicity to the oyster embryo. This corresponds with the current understanding of copper toxicity and supports the free-ion activity model for copper toxicity.

Quantitative analysis of oyster larval proteome provides new insights into the effects of multiple climate change stressors.

PubMed

Dineshram, Ramadoss; Chandramouli, Kondethimmanahalli; Ko, Ginger Wai Kuen; Zhang, Huoming; Qian, Pei-Yuan; Ravasi, Timothy; Thiyagarajan, Vengatesen

2016-06-01

The metamorphosis of planktonic larvae of the Pacific oyster (Crassostrea gigas) underpins their complex life-history strategy by switching on the molecular machinery required for sessile life and building calcite shells. Metamorphosis becomes a survival bottleneck, which will be pressured by different anthropogenically induced climate change-related variables. Therefore, it is important to understand how metamorphosing larvae interact with emerging climate change stressors. To predict how larvae might be affected in a future ocean, we examined changes in the proteome of metamorphosing larvae under multiple stressors: decreased pH (pH 7.4), increased temperature (30 °C), and reduced salinity (15 psu). Quantitative protein expression profiling using iTRAQ-LC-MS/MS identified more than 1300 proteins. Decreased pH had a negative effect on metamorphosis by down-regulating several proteins involved in energy production, metabolism, and protein synthesis. However, warming switched on these down-regulated pathways at pH 7.4. Under multiple stressors, cell signaling, energy production, growth, and developmental pathways were up-regulated, although metamorphosis was still reduced. Despite the lack of lethal effects, significant physiological responses to both individual and interacting climate change related stressors were observed at proteome level. The metamorphosing larvae of the C. gigas population in the Yellow Sea appear to have adequate phenotypic plasticity at the proteome level to survive in future coastal oceans, but with developmental and physiological costs. © 2016 John Wiley & Sons Ltd.

Interactive effects of ocean acidification, elevated temperature, and reduced salinity on early-life stages of the pacific oyster.

PubMed

Ko, Ginger W K; Dineshram, R; Campanati, Camilla; Chan, Vera B S; Havenhand, Jon; Thiyagarajan, Vengatesen

2014-09-02

Ocean acidification (OA) effects on larvae are partially attributed for the rapidly declining oyster production in the Pacific Northwest region of the United States. This OA effect is a serious concern in SE Asia, which produces >80% of the world's oysters. Because climate-related stressors rarely act alone, we need to consider OA effects on oysters in combination with warming and reduced salinity. Here, the interactive effects of these three climate-related stressors on the larval growth of the Pacific oyster, Crassostrea gigas, were examined. Larvae were cultured in combinations of temperature (24 and 30 °C), pH (8.1 and 7.4), and salinity (15 psu and 25 psu) for 58 days to the early juvenile stage. Decreased pH (pH 7.4), elevated temperature (30 °C), and reduced salinity (15 psu) significantly delayed pre- and post-settlement growth. Elevated temperature lowered the larval lipid index, a proxy for physiological quality, and negated the negative effects of decreased pH on attachment and metamorphosis only in a salinity of 25 psu. The negative effects of multiple stressors on larval metamorphosis were not due to reduced size or depleted lipid reserves at the time of metamorphosis. Our results supported the hypothesis that the C. gigas larvae are vulnerable to the interactions of OA with reduced salinity and warming in Yellow Sea coastal waters now and in the future.

Dual transcriptomics of virus-host interactions: comparing two Pacific oyster families presenting contrasted susceptibility to ostreid herpesvirus 1.

PubMed

Segarra, Amélie; Mauduit, Florian; Faury, Nicole; Trancart, Suzanne; Dégremont, Lionel; Tourbiez, Delphine; Haffner, Philippe; Barbosa-Solomieu, Valérie; Pépin, Jean-François; Travers, Marie-Agnès; Renault, Tristan

2014-07-09

Massive mortality outbreaks affecting Pacific oyster (Crassostrea gigas) spat in various countries have been associated with the detection of a herpesvirus called ostreid herpesvirus type 1 (OsHV-1). However, few studies have been performed to understand and follow viral gene expression, as it has been done in vertebrate herpesviruses. In this work, experimental infection trials of C. gigas spat with OsHV-1 were conducted in order to test the susceptibility of several bi-parental oyster families to this virus and to analyze host-pathogen interactions using in vivo transcriptomic approaches. The divergent response of these oyster families in terms of mortality confirmed that susceptibility to OsHV-1 infection has a significant genetic component. Two families with contrasted survival rates were selected. A total of 39 viral genes and five host genes were monitored by real-time PCR. Initial results provided information on (i) the virus cycle of OsHV-1 based on the kinetics of viral DNA replication and transcription and (ii) host defense mechanisms against the virus. In the two selected families, the detected amounts of viral DNA and RNA were significantly different. This result suggests that Pacific oysters are genetically diverse in terms of their susceptibility to OsHV-1 infection. This contrasted susceptibility was associated with dissimilar host gene expression profiles. Moreover, the present study showed a positive correlation between viral DNA amounts and the level of expression of selected oyster genes.