We examined the accumulation, subcellular distribution, and toxicity of Hg(II) and MeHg in three marine phytoplankton (the diatom Thalassiosira pseudonana, the green alga Chlorella autotrophica, and the flagellate Isochrysis galbana). For MeHg, the inter-species toxic difference could be best interpreted by the total cellular or intracellular ...

... assay was used to determine the subcellular location of this unassembled pilin and its fate during pilus assembly and cell division. ...

The mechanisms underlying heavy metal accumulation, toxicity and tolerance in higher plants are poorly understood. Since subcellular processes are undoubtedly involved in all these phenomena, it is of interest to study the extent of, subcellular site of a...

The subcellular localization of fission fragment (sup 147)Pm in tissue cells by electron microscopic autoradiography was investigated. The early harm of internal contaminated accumulation of (sup 147)Pm appeared in blood cells and endothelium cells, obvio...

Polymer therapeutics are being designed for lysosomotropic, endosomotropic and transcellular drug delivery. Their appropriate intracellular routing is thus crucial for successful use. For example, polymer-anticancer drug conjugates susceptible to lysosomal enzyme degradation will never deliver their drug payload unless they encounter the appropriate activating enzymes. Many studies use confocal ...

Prediction of metal bioaccumulation and toxicity in aquatic organisms has been based on the free ion activity (e.g., FIAM) or more recently on the binding with the biological/toxicological sites of action (e.g., biotic ligand model). However, metals are bound to various intracellular ligands that may control metal toxicity. In this study, we examined the bioaccumulation, ...

We explored the possible mechanisms leading to differential Cd sensitivity in three marine phytoplankton (the diatom Thalassiosira pseudonana, the dinoflagellate Prorocentrum minimum and the green alga Chlorella autotrophica) based on their Cd accumulation, Cd subcellular distribution, and phytochelatin (PC) synthesis. The most sensitive species, T. ...

Morphogenesis of the Drosophila embryonic trachea involves a stereotyped pattern of epithelial tube branching and fusion. Here, we report unexpected phenotypes resulting from maternal and zygotic (M/Z) loss of the homophilic cell adhesion molecule Echinoid (Ed), as well as the subcellular localization of Ed in the trachea. ed^M/Z embryos have convoluted ...

The Arabidopsis root epidermis is composed of two types of cells, hair cells and non-hair cells, and their fate is determined in a position-dependent manner. WEREWOLF (WER), a R2R3 MYB protein, has been shown genetically to function as a master regulator to control both of the epidermal cell fates. To directly test the proposed role of WER in this system, ...

The concentration of several marker enzymes for subcellular organelles has been determined in some marine animal species, which specifically accumulate heavy metals or radionuclides. The dependence of the enzyme activity on the incubation conditions was t...

The potential for trophic transfer of aluminium (Al) was investigated using a grazing detritivore, the freshwater snail Lymnaea stagnalis, and a predator, the signal crayfish Pacifastacus leniusculus. Snails were exposed to either aqueous Al (500 microg l(-1)) in the presence or absence of an inorganic ligand (phosphate (+P); 500 microg l(-1)) for 30 days, or kept as unexposed controls. ...

... chemical, genetic, and physiological influences that govern the accumul.ation- end biodegradation of po1ycyclJc aromatic hydrocarbons (PAHs). ...

Marine organisms are continuously exposed to heavy metals in their environment. Bivalve mollusks such as the blue mussel Mytilus edulis accumulate high levels of heavy metals effecting cellular homeostasis and functions. Lead (Pb) exposure (2.5 mg/L of lead (II) nitrate for 10 d) and depuration (10 d in clean seawater) experiments were conducted to study its intracellular ...

In order to investigate the basic mechanism of earthworm activities enhancing plants growth and heavy metals accumulations. A hydroponic experiment was carried out to investigate the effects of earthworm mucus and mimic amino acids solution of earthworm mucus on cadmium (Cd) subcellular distributions and chemical forms in tomato seedlings. The result ...

The retentive peculiarity of soluble enriched uranium UO(sub 2)F(sub 2) in subcellular level was studied by electron microscopic autoradiography. The early dynamic accumulation of radioactivity in the body showed that enriched uranium UO(sub 2)F(sub 2) wa...

Phosphite (Phi, H(2)PO(3)(-)), being the active part of several fungicides, has been shown to influence not only the fungal metabolism but also the development of phosphate-deficient plants. However, the mechanism of phosphite effects on plants is still widely unknown. In this paper we analysed uptake, subcellular distribution and metabolic effects of Phi in tobacco BY-2 cells ...

Egr-1 is an "immediate early" gene that is induced by growth factors and agents that induce differentiation and encodes a protein with a "zinc-finger" motif. This protein is believed to be involved in transcriptional regulation. Because the fate of the kidney, and hence the organism, after an ischemic insult is dependent upon cellular repair, differentiation, and ...

Retinal neurons from rats acutely intoxicated with trimethyltin (TMT) were examined by light and electron microscopy to determine if there is a relationship between the subcellular response of a neuron to TMT and its morphologic subspecialization. Subcellular pathologic alterations were present in neurons from all three cellular layers of the sensory ...

We have examined the relationships between Cd ion activity (Cd/sup 2 +/), in seawater, Cd accumulation and subcellular distribution and growth in the polychaete Neanthes arenaceodentata. Organisms were exposed for 3 weeks to a range of (Cd/sup 2 +/) in a Cd-chelate buffer system. Cadmium accumulation and growth were monitored weekly ...

Catharanthus roseus synthesizes a wide range of valuable monoterpene indole alkaloids, some of which have recently been recognized as functioning in plant defence mechanisms. More specifically, in aerial organ epidermal cells, vacuole-accumulated strictosidine displays a dual fate, being either the precursor of all monoterpene indole alkaloids after export ...

A growing concern exists that the accumulation of unexploded or unconsumed energetic compound residues in soils on military testing and training ranges represents a threat to human health and the environment and that the ultimate fate and transport of the...

The authors administered to E. coli auxotroph analogues of the required amino-acids and studied the subsequent fate of the analogue-containing polypeptides. Previous studies of protein breakdown in bacteria have generally overlooked the possibility that s...

The coupling of benthic-pelagic processes is central to understanding the fate of nutrients and organic matter in the Mississippi River Plume and adjacent continental shelf. Chapters in this technical summary describe the accumulation and regeneration of ...

Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is the predominant protein in photosynthesizing plant parts and the most abundant protein on earth. Amino acids deriving from its net degradation during senescence are transported to sinks (e.g. developing leaves, fruits). Rubisco catabolism is not controlled only by the overall sink demand. An accumulation of ...

Seed storage proteins (SSPs) have been studied for more than 250�years because of their nutritional value and their impact on the use of grain in food processing. More recently, the use of seeds for the production of recombinant proteins has rekindled interest in the behavior of SSPs and the question how they are able to accumulate as stable storage reserves. Seed cells ...

We have examined the underlying mechanisms of subcellular copper and cadmium metabolism in larvae of the mud crab, Rhithropanopeus harrisii, and the polychaete worm, Neanthes arenaceodentata. In developing crab larvae we found that Cu accumulation is prec...

of pesticides: a) Proposition 65 list (known to cause reproductive toxicity). b) B2 carcinogens, or Proposition

A method of detecting Alzheimer's disease includes detecting a disruption or alteration in normal sub-cellular distribution of G-protein receptor kinases (GRKs), particularly GRK2 and GRK5. The disruption is caused by abnormal accumulation of soluble .bet...

Munitions materials can accumulate or cycle in terrestrial environs at production and manufacturing facilities and thus pose potential heath and environmental concerns. To address questions related to food chain accumulation, the environmental behavior of...

Microbial biofilms, composed of microorganisms originally obtained from harbor-exposed organotin-painted panels, accumulated tributyltin (TBT) spiked into estuarine water. Algal and bacterial-dominated biofilms were grown by varying nutrient conditions. B...

Phytoplankton has been reported to accumulate mercury within the cells rapidly and efficiently. The intracellular distribution of mercury in plankton, Synedra cells has been investigated by measuring the amounts of radioactive mercury incorporated into various subcellular components. After labeling the cells with radioactive mercury, they were disrupted by ...

The mechanisms underlying heavy metal accumulation, toxicity and tolerance in higher plants are poorly understood. Since subcellular processes are undoubtedly involved in all these phenomena, it is of interest to study the extent of, subcellular site of and nature of intracellularly accumulated cadmium in higher ...

BackgroundBecause of the increasing quantity and high toxicity to humans of polycyclic aromatic hydrocarbons (PAHs) in the environment, several bioremediation mechanisms and protocols have been investigated to restore PAH-contaminated sites. The transport of organic contaminants among plant cells via tissues and their partition in roots, stalks, and leaves resulting from transpiration and lipid ...

Zinc homeostasis was studied at the tissue and gill subcellular levels in rainbow trout (Oncorhynchus mykiss) following waterborne and dietary exposures, singly and in combination. Juvenile rainbow trout were exposed to 150 or 600microgl(-1) waterborne Zn, 1500 or 4500microgg(-1) dietary Zn, and a combination of 150microgl(-1) waterborne and 1500microgg(-1) dietary Zn for 40 ...

The extensive use of nanoparticles (NPs) in a variety of applications has raised great concerns about their environmental fate and biological effects. This study examined the impact of dissolved organic matter (DOM) and salts on ZnO NP dispersion/solubility and toxicity to the earthworm Eisenia fetida. To be able to better evaluate the toxicity of NPs, exposure in agar and on ...

The generation of distinct cell fates can require movement of specific molecules or organelles to particular locations within the cell. These subcellular movements are often the jobs of motor proteins. Seemingly disparate developmental processes--determination of right and left in vertebrates, setting up the axes of polarity in insect embryos, mating-type ...

The present study was undertaken to elucidate the cellular mechanisms, which govern metal sequestration and detoxification in gastropods. For this purpose the pond snail, Lymnaea stagnalis was exposed to environmentally relevant concentrations of three species of metals (Al, Zn and Cd) for 30 days and the localization and fate of these metals were followed in different tissues ...

When the process of cell-fate determination is examined at single-cell resolution, it is often observed that individual cells undergo different fates even when subject to identical conditions. This "noisy" phenotype is usually attributed to the inherent stochasticity of chemical reactions in the cell. Here we demonstrate how the observed single-cell ...

SUMMARYWhen the process of cell-fate determination is examined at single-cell resolution, it is often observed that individual cells undergo different fates even when subject to identical conditions. This �noisy� phenotype is usually attributed to the inherent stochasticity of chemical reactions in the cell. Here we demonstrate how the observed ...

We examined the subcellular partitioning of zinc (Zn) in Daphnia magna both under acute and chronic exposures. In the acute Zn toxicity tests, the daphnids were exposed to different Zn concentrations for 48 h or to one lethal concentration (1,000 microg/L) for different durations (time to death for up to 47 h). Significant mortality of daphnids was observed when the newly ...

Zeins are the major storage proteins in maize (Zea mays) endosperm, and their accumulation in zein bodies derived from the endoplasmic reticulum is well characterized. In contrast, relatively little is known about post-Golgi compartments or the trafficking of vacuolar proteins in maize endosperm, specifically the presence of globulins in structures resembling protein storage ...

BackgroundGene duplication is a key evolutionary mechanism providing material for the generation of genes with new or modified functions. The fate of duplicated gene copies has been amply discussed and several models have been put forward to account for duplicate conservation. The specialization model considers that duplication of a bifunctional ancestral gene could result in ...

The objectives of this project are to (1) monitor cellular metabolism and fate of fossil fuel-related pollutants and (2) determine effects of these agents on regulation of gene structure indicative of changes in gene expression or gene replication. Alteration of either of these processes by fossil fuel-related agents would indicate the potential of the agent to cause either ...

Silver nanoparticles (AgNPs) are widely used which may result in environmental impacts, notably within aquatic ecosystems. As estuarine sediments are sinks for numerous pollutants, but also habitat and food for deposit feeders such as Nereis diversicolor, ingested sediments must be investigated as an important route of uptake for NPs. N. diversicolor were fed sediment spiked with either citrate ...

The distributions of two endocytosed radiolabelled ligands (polymeric immunoglobulin A and asialofetuin) in rat liver endocytic compartments were investigated by using rapid subcellular fractionation of post-mitochondrial supernatants on vertical density gradients of Ficoll or Nycodenz. Two endocytic compartments were identified, both ligands being initially associated with a ...

In many tissues in many organisms, messenger RNA (mRNA) is not randomly distributed throughout a cell, but is targeted and accumulated in specific subcellular locations. Signal transduction pathways can be extremely sensitive to gradients of signaling proteins and represent a cellular phenomenon where RNA localization may be important. Manseau discusses ...

Potentilla griffithii Hook is a newly found hyperaccumulator plant capable of high tolerance and accumulation of Zn and Cd. We investigated the interactive effects between Cd and Zn on accumulation and vacuolar sequestration in P. griffithii. Stimulatory effect of growth was noted at 0.2 mM Cd and 1.25 and 2.5 mM Zn tested. ...

Radioactive contaminants from the usage of radioactive materials include debris from the testing of nuclear devices and wastes from industrial, research, and medical users of radioelements. The fate of the radioactive contaminants, subsequent to their initial deposition, is traced. The kinds and amounts of radioelements that become accumulated by ...

The Americium 241 radioelement accumulation and elimination rate and mechanisms in the lobster organism have been experimentally studied; incorporation and detoxification capacities of each organ are evaluated. The existence of various biological compartm...

BackgroundThe first step in glucose metabolism is conversion of glucose to glucose 6-phosphate (G-6-P) by hexokinases (HKs), a family with 4 isoforms. The two most common isoforms, HKI and HKII, have overlapping tissue expression, but different subcellular distributions, with HKI associated mainly with mitochondria and HKII associated with both mitochondrial and cytoplasmic ...

Land application of solid wastes leads to the accumulation of both metals and antimicrobials in soils. To understand the effects of metal and antibiotic interaction on their accumulation by the earthworm Eisenia fetida, uptake and elimination kinetics and subcellular distribution of cadmium (Cd) and ciprofloxacin (CIP) were determined. ...

Concentrations of total arsenic and individual arsenic compounds were determined in liver samples of pinnipeds (northern fur seal Callorhinus ursinus and ringed seal Pusa hispida), seabirds (black-footed albatross Diomedea nigripes and black-tailed gull Larus crassirostris) and sea turtles (hawksbill turtle Eretmochelys imbricata and green turtle Chelonia mydas). Among these species, the ...

To understand bioaccumulation kinetics of metals within biota inhabiting industrially contaminated soils, toxicokinetic dynamics and subcellular fractionation were carried out with the terrestrial snail Helix aspersa in a long-term (six-month) laboratory experiment. Accumulation and elimination kinetics were determined for Cd, Pb, and Zn in both viscera ...

? We studied the subcellular levels of melatonin in cerebral cortex and liver of rats under several conditions. The results show that melatonin levels in the cell membrane, cytosol, nucleus, and mitochondrion vary over a 24-hr cycle, although these variations do not exhibit circadian rhythms. The cell membrane has the highest concentration of melatonin followed by ...

Interactions of Cu, Cd and Zn were studied at the subcellular level in juvenile rainbow trout (Oncorhynchus mykiss) fed diets containing (?g/g) 500 Cu, 1000 Zn and 500 Cd singly and as a ternary mixture for 28 days. Livers were harvested and submitted to differential centrifugation to isolate components of metabolically active metal pool (MAP: heat-denaturable proteins (HDP), ...

There is an increasing body of evidence that illustrates that low levels of manmade chemicals (xenobiotics) that made their way into wastewater influents accumulate onto the sewage sludge. There is a growing concern the release of these chemicals in the environment through the land application of b...

In this study, 17 organic pesticides and five industrial chemicals were examined in a terrestrial-aquatic model ecosystem in an effort to determine their persistence and accumulation by the organisms of this system. Several classes of pesticides are repre...

Disposal of saline subsurface drainage waters from croplands into evaporation basins (or ponds) in the San Joaquin Valley of California causes excessive accumulation of salts and elevated concentrations of arsenic (As), a potentially high risk element with little information about its fate, in the a...

The water storage capacity and dam integrity of thousands of flood control reservoirs built since 1950 are potentially compromised by excessive impounded sediments. The fate of these structures depends on the amount and characteristics of this accumulated material. To aid in understanding the scop...

Our research is motivated by the need to protect the human chain and the environment from contamination by agricultural and industrial toxic chemicals. he objective of our research is to learn what plant mechanisms determine uptake, translocation, accumulation, and biodegradation...

Many large outflow channels terminate in the low-lying northern plains. If the outflow channels formed by running water, as appears likely, then standing bodies of water must have accumulated at the ends of the channels. Most of the observed channels, and...

Cadmium was continuously input to aquatic microcosm channels resulting in concentrations of 5 and 10 micrograms Cd/l. Cadmium accumulation into both biotic and abiotic components was determined. Biological effects of cadmium were determined by monitoring ...

The objective of the report is to determine the distribution of selected metals in suspended material and fluid mud, to identify potential zones of toxic accumulation, and to trace their transport routes. Observations of flow, salinity, suspended material, pH, and dissolved oxyge...

Cadmium was continuously input to aquatic microcosm channels resulting in concentrations of 5 and 10 micrograms Cd/l. Cadmium accumulation into both biotic and abiotic components was determined. Biological effects of cadmium were determined by monitoring structural and functional...

Anaerobic cultures of Escherichia coli exposed to paraquat (PQ2+) accumulated the corresponding monocation radical PQ+, both within the cells and in the suspending medium. The green alga, Dunaliella salina, which is susceptible to a light and O2-dependent...

The objectives of the research described in this report are to characterize the deposition and accumulation of propellant residues at the various types of firing points at military firing ranges, develop process descriptors to allow estimation of environm...

To assess the fate of current-use pesticides it is important to understand their bioaccumulation and biotransformation by aquatic biota. We examined the dietary accumulation and enantioselective biotransformation of the chiral current-use pesticide fipronil, along with a mixture ...

Salmonellae are the bacterial pathogens which are most frequently associated with oysters from polluted waters. However, there is little information on the concentration of salmonellae in oysters from polluted waters because most tests for salmonellae are...

not accumulate when methanol is oxidized. Considering the known high toxicity of formaldehyde, the priority Chemistry and Physics Discussions A fate for organic acids, formaldehyde and methanol in cloud water, acetate, lactate, succinate, formaldehyde and methanol. Biodegradation tests show that all these compounds

Subcellular distribution of Cu, Zn, Se, Rb, Mo, Ag, Cd and Pb was determined in the liver of green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) from Yaeyama Islands, Japan. Also, hepatic cytosol from sea turtles was applied on a Sephadex G-75 column and elution profiles of trace elements were examined. Copper, Zn, Se, Rb, Ag and Cd were largely ...

To explore the extent to which current knowledge about the organelle-targeting features of small molecules may be applicable toward controlling the accumulation and distribution of exogenous chemical agents inside cells, molecules with known subcellular localization properties (as reported in the scientific literature) were compiled into a single data set. ...

The present study examined how subcellular partitioning of Cd in plants with different strategies to store and detoxify Cd may affect trophic transfer of Cd to the isopod Porcellio dilatatus. The plant species used were Lactuca sativa, a horticultural metal accumulator species; Thlaspi caerulescens, a herbaceous hyperaccumulator species; and the ...

Comparative studies of vulva development between Caenorhabditis elegans and other nematode species have provided some insight into the evolution of patterning networks. However, molecular genetic details are available only in C. elegans and Pristionchus pacificus. To extend our knowledge on the evolution of patterning networks, we studied the C. elegans male hook competence group (HCG), an ...

In the present study, rock oysters (Saccostrea cucullata) were first exposed to cadmium and zinc for two weeks to modify their subcellular metal partitionings. The relationship between subcellular metal (Cd and Zn) partitioning in the oysters and metal bioaccumulation and fractionation in predatory gastropods (Thais clavigera) was then examined by feeding ...

Protein phosphorylation controls many aspects of cell fate and is often deregulated in pathological conditions. Several recent findings have provided an intriguing insight into the spatial regulation of protein phosphorylation across different subcellular compartments and how this can be finely orchestrated by specific kinases and phosphatases. In this ...

Local, efflux-dependent auxin gradients and maxima mediate organ and tissue development in plants. The auxin-efflux pattern is regulated by dynamic expression and asymmetric subcellular localization of PIN auxin-efflux proteins during plant organogenesis. Thus, the question of how the expression and subcellular localization of PIN proteins are controlled ...

The use of Rosmarinus officinalis, and other wild plant species, in the Mediterranean area is an interesting solution in order to avoid the desertification and rapid soil erosion, because of their good resistance to environmental conditions. Previous articles have described experiments designed to determine the impact of water stress at the plant level in this species, but more knowledge is ...

Because the initial stages of pathogen invasion are often confined to a limited number of host cells, measures of host responses that are averaged over attacked and non-attacked cells provide an unsatisfactory view of these events. To identify the earliest and often transient responses to pathogen attack, there is considerable interest in monitoring the subcellular events that ...

Lipid movement between organelles is a critical component of eukaryotic membrane homeostasis. Niemann Pick type C (NP-C) disease is a fatal neurodegenerative disorder typified by lysosomal accumulation of cholesterol and sphingolipids. Expression of yeast NP-C�related gene 1 (NCR1), the orthologue of the human NP-C gene 1 (NPC1) defective in the disease, in Chinese hamster ...

Identification of lipophilic chemicals requires the development of new techniques to detect these compounds at the cellular and subcellular levels. To address this issue, we have developed a combinational protocol using antibodies directed against chemicals together with a multiple signal amplification system (catalyzed signal amplification/gold-substituted silver-intensified ...

We have examined the underlying mechanisms of subcellular copper and cadmium metabolism in larvae of the mud crab, Rhithropanopeus harrisii, and the polychaete worm, Neanthes arenaceodentata. In developing crab larvae we found that Cu accumulation is precisely regulated at lower exposures. At exposures higher concentrations than those normally found in the ...

Subcellular fractionation of rat spinal cord on continuous sucrose density gradients provides evidence for the existence of a specific synaptosomal fraction (enriched in pinched-off nerve endings) that accumulates glycine selectively by way of a high-affinity transport system. The particles in this fraction sediment to a less-dense portion of sucrose ...

The fate of minerals can be conveniently studied through intrinsic labeling techniques. The mineral of interest is biologically incorporated into the food in a form that can be distinguished analytically from the natural form of the element. Radiolabels have traditionally been used to study such problems as the uptake of minerals by plants, the gross and ...

This report describes a model developed to simulate the fate of individual PAH's in aquatic systems, summarizes current applications of the model, evaluates its precision for forecasting, and outlines future requirements for refinement of the model. The hypothesis is that the fate of PAH's can be forecast from fundemental, easily measured ...