Biodepressive effect of zinc on humoral effector of theHolothuria polii immune response

High zinc ion concentrations produce an inhibitory effect on the naturally occurring hemolytic activity of theHolothuria polii coelomic fluid and coelomocyte lysate. The naturally occurring hemagglutinating activity remains unaffected. The inhibition appears reversible, suggesting a non-covalent interaction of the ions with the hemolysins. Moreover, as demonstrated by SDS-PAGE and immunoblotting analysis, the Zn⁺⁺ treatment does not produce molecular weight variations in the coelomic fluid and coelomocyte lysate hemolytic patterns. This study was conducted during 1987 on samples gathered from the Gulf of Palermo, Italy.     

TAR柱前络合、毛细管电泳分析痕量金属离子

1　IntroductionTransitionmetalswereamongthemostconcernelementsinenvironmentalanalysisduetotheirpotentialrolestoplantandanimals[1 ].Theserolesoftransitionmetalsinenvironmentdependedontheirconcentrationinthesoil,waterandlivingthings.Currently ,themostutiliz…     

Hemolysins from the mucus of Spirographis spallanzani (Polychaeta: Sabellidae)

Specimens of Spirographis spallanzani (Polychaeta: Sabellidae) were collected in the Gulf of Taranto, Italy, in 1991, and their mucous secretion was examined. The mucus possesses thermolabile biologically active proteins which produce hemolysis in vertebrate erythrocytes. The molecules are ineffective against both unfertilized and fertilized echinoid eggs and spermatozoa. The lytic reaction against rabbit erythrocytes varies as a function of cations, pH and temperature, and displays a fast time-course. No immunological cross-reaction could be demonstrated between hemolysins of S. spallanzani and Eisenia foetida andrei. SDS-PAGE analysis of mucus proteins reacting with sheep erythrocytes revealed that at least three major (16, 22 and 40 kDa) and two minor (29 and 34 kDa) components interact with membrane targets.     

Histological and histochemical changes in the gills of the yellowtail Seriola quinqueradiata exposed to the Raphidphycean flagellate Chattonella marina

The gills of the yellowtail Seriola quinqueradiata, exposed to Chattonella marina a red tide species, were examined histologically and histochemically. The pavement cells of primary lamellae were swollen in the exposed specimens. This presumably indicates that C. marina contains undetermined toxic substances. The number of mucous cells containing mucous decreased in proportion to the duration of exposure. The loss of the mucous substance in the cells is probably due to the ichthyotoxic stimulus caused by C. marina. A decrease of carbonic anhydrase activity in the secondary lamellae was confirmed, when mucous substances were lost in most mucous cells. Since the carbonic anhydrase usually exists in the epithelia of the secondary lamellae, it was presumably resolved by C. marina. The decrease of the carbonic anhydrase activity may cause certain physiological disadvantages to the fish exposed to C. marina.     

Studies on arylsulphatases in the barnacle Balanus eburneus

Arylsulphatases (ASases) have been identified in the mantle tissues of the barnacle Balanus eburneus Gould. This is the first report of these enzymes in the Cirripedia. Using p-nitrocatechol sulphate (NCS) as a substrate, the optimum pH for activity was found to be 5.6 in 0.5 M-acetate buffer, and substrate concentration of 12 mM. The activity of the enzyme was strongly inhibited by phosphate, sulphite and sulphate and not by cyanide, indicating the presence of Type II ASase. Biochemical and electrophoretic studies revealed the coexistence of at least two distinct Type II ASases in the mantle tissues. These are probably similar to the ASase-A and ASase-B reported for vertebrate tissues. The presence of multiple molecular forms of ASase capable of hydrolyzing potassium 6-benzoyl-2-naphthyl sulphate was demonstrated by polyacrylamide gel disc-electrophoresis. The activity patterns of ASases in the mantle tissues were studied in relation to the molt cycle. The activity of ASase-B followed a cyclic pattern which correlated with the molt stages, reaching a maximum in the postmolt. The activity of ASase-A remained essentially the same during the entire molt cycle. Analysis of the activities after dialysis indicates a change in the activity of ASase-B into a non-fluctuating pattern. The enzyme was found in all stages of development, with a ninefold increase in activity in adult forms. The fact that a greater activity was found in the nondigestive organs and that there is an increase in the activity of ASase in tissues of unfed (starved) specimens indicates that the enzyme does not function in the digestive processes, as suggested for other animals by certain investigators. The evidence in this study implicates a major role for dialyzable inhibitory factor(s) as the mechanism involved in the regulation of the activity of ASase-B during the molt cycle. The possible relationship of endogenous phosphate and/or neurosecretory substance(s) with the dialyzable inhibitory factor(s) is discussed. A discussion speculating on the relationship of ASase activity to the cyclic formation and hardening of the exoskeleton and adhesive substance(s) is also presented.     

Chitobiase activity in the epidermis and hepatopancreas of the fiddler crab Uca pugilator during the molting cycle

The activity of chitobiase, also known as N-acetyl-β-glucosaminidase, in the epidermis and hepatopancreas of the fiddler crab Uca pugilator (Bosc, 1802), during the molting cycle, was investigated. A pH optimum of 5 to 6 was found for the enzymatic activity in both the epidermis and hepatopancreas. The temperature optimum for epidermal and hepatopancreatic chitobiase activities was 50 to 60 °C. The K _m values for epidermal and hepatopancreatic chitobiase activities at 19 °C were 0.190 ± 0.027 and 0.203 ± 0.016 mM 4-methylumbelliferyl-N-acetyl-β-glucosaminide, respectively. Hepatopancreatic chitobiase activity was significantly higher than epidermal enzymatic activity in all the molt cycle stages tested except Postmolt Stage A-B. Chitobiase activity varied significantly during the molting cycle, with the epidermal enzymatic activity in Premolt Stage D_3–4 significantly higher than in Stage C (intermolt) and Premolt Stage D₀, whereas hepatopancreatic chitobiase activity in Premolt Stage D_3–4 was significantly higher than in all other molt stages tested. The patterns of chitobiase activity in the epidermis and hepatopancreas correlate well with the hemolymph titer of ecdysteroids in U. pugilator during the molting cycle; this suggests that chitobiase activity in both tissues is regulated at least in part by the steroid molting hormones. Received: 6 May 1998 / Accepted: 12 September 1998     

Composition of the proteinaceous gel secretion from the skin of the Arabian Gulf catfish (Arius thallasinus)

The Arabian Gulf catfish Arius thallasinus excretes copious amounts of proteinaceous gel from epidermal cells when threatened or injured. As a means of investigating its biological role, this gel material has been examined to determine the nature of the secretion and its associated biological activities. Over 85% of the dry weight of the gel material is protein with small amounts of lipids, carbohydrates and nucleic acid components. Most of the protein exists as a high molecular weight aggregate of predominantly 13 500 molecular weight monomeric units. Several lytic enzyme activities are found in the gel secretion, one of which catalyzes lysis of red blood cells. Other factors induce clotting in citrate treated plasma and agglutination of red blood cells. The enzymic properties of the gel secretion resemble those of some animal venoms.     

Influence of phosphate depletion on the growth and colony formation of Phaeocystis pouchetii

The haptophycean alga Phaeocystis pouchetii (Hariot) Lagerheim, a bloom-forming species in the North Sea, formed massive colonies in batch cultures only when the phosphate concentration in the medium was below 1 mol l^-1. In general, colony cells and single cells showed a similar response to phosphate depletion: decreased cellular phosphate (up to a factor of 32), decreased chlorophyll-a concentration (up to a factor of 4.2) and high activities of alkaline phosphatase (APA). However, the growth rate of colony cells was reduced at low phosphate concentrations (<1 mol l^-1) in contrast to that of single cells. Colony cells tended to have a slightly higher phosphate concentration than single cells, while the increase in APA was delayed. The differences between single cells and colonies in phosphate utilization, cellular phosphate content, and growth rate cause, at low phosphate levels, a shift towards the formation of colonies. Similar changes seem to occur in nature during transition of nutrient-sufficient to nutrientlimited conditions.This investigation was supported by the Foundation for Fundamental Biological Research (BION), which is subsidized by the Dutch Organization for the Advancement of Pure Research (ZWO). Publication No. 8 of the project Ecological Research of the North Sea (EON)     

营养盐对海洋卡盾藻生长与产毒的影响（Effect of Some Nutrients on the Growth and Haemolytic Toxins Production of Chattonella marina）

海洋卡盾藻(Chattonella marina)是我国南方重要的有害赤潮原因种,其产生的溶血毒素、活性氧等可能是造成鱼类死亡的重要原因.在实验室条件下,研究了氮、磷和铁等营养盐对海洋卡盾藻生长及产毒的影响,以期为阐明海洋卡盾藻溶血毒素生成机制奠定基础.研究结果发现:在铁、氮、磷盐三因素四水平正交实验条件下,铁盐和氮盐是影响海洋卡盾藻生长的显著因子;氮盐和磷盐是影响海洋卡盾藻产毒的显著因子;铁盐浓度0.492mg·L-1、氮盐浓度375mg·L-1、磷盐浓度5mg·L-1时海洋卡盾藻的比生长速率最大;铁盐浓度0mg·L-1、氮盐浓度375mg·L-1、磷盐浓度0.5mg·L-1时海洋卡盾藻的产毒能力最强,即高氮、低磷条件下有利于海洋卡盾藻溶血毒素的合成.     

Egg protein insolubility inLymantria dispar versus other forest Lepidoptera

Summary A standard buffer (5 mM phosphate at pH 7) which is used to extract protein from insect eggs provided complete protein solubility for eggs from three of four tree-feeding lepidopteran species: obliquebanded leaf roller (Choristoneura rosaceana), forest tent caterpillar (Malacosoma disstria), and the eastern tent caterpillar (Malacosoma americanum). Under the same extraction protocol, egg proteins from the gypsy moth (Lymantria dispar), remained nearly insoluble. An array of methods typically used to solubilize insect egg proteins were tried and all but the most denaturing (2% SDS) were ineffective. Extraction buffers with typically high pH values were then evaluated. The results indicated that 1) solubility of gypsy moth egg proteins was pH dependent, and full solubility of most egg proteins required the extraction buffer to have a pH of 12 or more prior to the addition of eggs. We also determined that 2) the gypsy moth egg has a buffering capacity which must be surpassed for complete protein extraction, 3) low salt/high pH buffers gave slightly higher total protein values than did high salt/high pH buffers, 4) parental nutritional history (host species utilized) and egg developmental state (pre-embryonatedvs postembryonated/pre-hatch) were unrelated to the requirements for complete egg protein solubilization, and 5) the presence of soluble phenolics, compounds that have the potential to bind to protein and cause insolubility, was confirmed for the gypsy moth egg with 2-D paper chromatography and several other tests. Based on these results, we present a hypothesis about the cause of egg protein insolubility in the gypsy moth.     

The effect of food supply on feeding strategy in sessile female gastropods<Emphasis Type="Italic"> Crepidula fecunda</Emphasis>

Sessile females of the gastropod Crepidula fecunda are exclusively suspension-feeders. Our previous work showed that particles removed from suspension are entrained on the gill and continuously accumulate as a mucous string on the distal margin of the lamella, although some are transferred by a ciliary tract to the food pouch, where they form a mucous ball. The mucous string is transferred from the gill margin to the neck canal, where it forms a mucous cord which is transported to the mouth. The mucous ball and the mucous cord are ingested with the aid of the radula. In this study we examined the response of the system to a wide range of cell concentrations of the flagellate Isochrysis galbana. As the particle concentration increased from 5,000 to 200,000 cells ml^-1, the volume of the mucous ball almost doubled, as did the number of radular extrusions required to ingest it. The total volume of mucous balls produced and ingested increased very slightly as particle concentration rose from 5,000 to 100,000 cells ml^-1, but the volume of mucous cord material ingested increased four to five times over the same range. At higher food concentrations the mucous cord increased in thickness, but not in length, which is constrained by the length of the gill margin. At all particle concentrations the mucous cord accounted for 80–95% of the total material (mucous cords plus mucous balls). Ingestion rate reached a maximum at 140,000 cells ml^-1 for mucous balls and mucous cords. At higher concentrations the production of pseudofaeces increased from all sources ("type-I" pseudofaeces from rejected mucous balls; "type-II" pseudofaeces from rejected fragments of mucous cords; and "type-III" pseudofaeces, which come from particles trapped in a coarse mucous net at the mouth of the inhalant mantle cavity and are transferred via the lateral ciliary tract to the mantle margin, by-passing the food pouch). Thus C. fecunda has adopted a feeding strategy in which particle entrainment by the gills is continuous, even at very high ambient particle concentrations (200,000 cells ml^-1 for I. galbana), and excess material which cannot be ingested is rejected by one or more of three routes for the elimination of pseudofaeces.Communicated by P.W. Sammarco, Chauvin     

Seasonal cycle of lysosomal enzyme activities in the mantle tissue and isolated cells from the musselMytilus edulis

InMytilus edulis L., gametogenesis takes place in the mantle at the expense of the connective storage tissue. There are two main types of storage cells: vesicular (VC) cells storing large amounts of glycogen and adipogranular (ADG) cells containing large numbers of protein granules, lipid droplets and lesser amounts of glycogen. One of the ways in which stored reserves can be mobilized for gamete formation is by controlled autophagy, in which the cellular constituents are degraded by lysosomes. Mussels were collected from the Menai Strait, North Wales, and monthly measurements made, over two years (1984–1986), of the activities of lysosomal acid hydrolases (acid phosphatase,-N-acetyl-D-glucosaminidase and-glucuronidase) and Cathepsins B and L in the mantle tissue, isolated ADG cells, low-density cells and, during spawning, in the mature oocytes of female mussels. The lysosomal proteinases, Cathepsins B, L and H, were further characterised by activation with thiol compounds and inhibition with thiol blockers and by leupeptin. Because of the low activity in the mantle tissue ofM. edulis, Cathepsin H was not assayed on a seasonal basis. There was a general increase in lysosomal enzyme activity during the winter, which can be related to increased autolysis in the storage cells and to the process of maturation in the developing oocytes. The activity of Cathepsin B was highest in the ADG and low-density cells, implying an important role in proteolysis within the ADG cells. By contrast, Cathepsin L displayed the highest activity in the mature oocytes, suggesting a major function of Cathepsin L in the development and maturation of the oocytes. Two different-glucosidase activities were measured in the monthly assays, one with a pH optimum of 4.5 (acid) and the other at pH 7.5 (neutral). Highest activities of the acid-glycosidase were found in the low-density cells, but there were no significant seasonal changes in the mantle tissue as a whole. Activities of the neutral-glucosidase were low in the ADG cells and mature oocytes, but showed high activities in the mantle tissue, with marked seasonal changes that corresponded to the mobilization of glycogen reserves in the VC cells.     

Purification,characterization and toxicity of a mannose-binding lectin from the seeds of Treculia africana plant

In this study, a mannose-specific, homodimeric lectin from the seeds of Treculia africana was purified, characterized and its adverse effects were investigated in mice. The purification protocol involved anionic exchange chromatography on DEAE-Cellulose followed by gel filtration on Sephadex G-100. The hemagglutinating activity of lectin towards human erythrocytes was sensitive to inhibition by D-mannose. Treatment of the protein with EDTA exerted no inhibitory effect; however, analysis of metal content by atomic absorption spectroscopy revealed the presence of Cu²⁺, Fe³⁺, and Mg²⁺. The results obtained showed that the lectin possesses maximum hemagglutinating activity towards human erythrocytes activity over the pH range 3–7.2 and is relatively thermostable up to 50°C. Periodic acid Schiff's (PAS) reagent staining showed that the protein was non-glycosylated while its amino acid composition analysis revealed that the protein contained 155 residues per subunit. The subunit had a minimal molecular weight of 22,139 Daltons, while the native molecular weight was estimated to be 41,000 Daltons. The lectin was found to be moderately toxic to mice with an LD₅₀ of 47.21 µg g^?1 body weight while, histopathological analysis showed no treatment related effects in any of the organs examined.     

Resting spore formation and phosphorus composition of the marine diatom Chaetoceros pseudocurvisetus under various nutrient conditions

The marine diatom Chaetoceros pseudocurvisetus was used for a study of resting spore formation and cellular phosphorus composition. Resting spores were found in any culture medium with ample silica, including nitrogen limited, phosphorus limited and nutrient replete conditions. Resting spores protected themselves with thick silica walls, so that vegetative cells required about 3 pmol cell^-1 of additional silica to form resting spores. Phosphorus compounds in the cells were divided into eight fractions: nucleotide-P, orthophosphate, acid soluble polyphosphate, sugar phosphate, nucleic acid-P, acid insoluble polyphosphate, lipid-P and residual-P. The sum of orthophosphate, sugar phosphate and nucleic acid-P comprised over 65% of the total phosphorus in cells under any culture conditions. Sugar phosphate was the most variable component, being most abundant in vegetative cells and least abundant in resting spores.     

On the biology of Berthellina citrina (Gastropoda: Opisthobranchia) and its defensive acid secretion

The opisthobranch gastropod Berthellina citrina (Ruppel and Leuckart, 1828¹) was collected from shallow water in the Gulf of Elat (Red Sea), where it is encountered only on sandy substrata overlaid with stones. The mollusc is nocturnal, feeds on various types of sponges, and hides during the day under stones. It releases an acid secretion (pH 1) containing sulphate and chlorine ions. This secretion is released, as a response to stimulation, from the entire body surface. In histological sections stained by standard dyes, the secretory cells remain colorless. In controlled laboratory experiments, it was found that this acid secretion protects B. citrina against all tested sea anemones, fishes, and crustaceans.     

Ultrastructure effects of omethoate and cypermethrin insecticides on maize seedlings

Increasing studies suggest that insecticides are one of the plant stress elements that affect plant growth and productivity by interfering with cell metabolic and biochemical activities. Here, we show that the application of commonly used pesticides omethoate and cypermethrin on maize (Zea mays L. cv. Luyu 9) seedling leaves resulted in adverse effects on leaf ultrastructure changes under laboratory conditions. Electron microscopic studies reveal that the topical application of organophosphorus insecticide omethoate causes direct injury of leaf ultrastructures including cell wall breakdown of abaxial epidermis cells, inner cells, stomata guard cells; degradation of mitochondrial membrane, and chloroplast envelope membrane; and abnormal changes of lamella arrangement of chloroplast. And the topical application of cypermethrin insecticide causes plasmolysis of cells of the adaxial epidermis, mitochondrial cristae are degraded, and loosen arranged lamella of amyloplasts. All these changes indicated that omethoate and cypermethrin are stress factors that caused adverse effects on plant ultrastructures and biochemical molecules.     

Genotoxicity of chromium in vitro on yeast: Interaction with DNA†

The genotoxicity of chromium chloride was investigated in cells of D₇ strain of Saccharomyces cerevisiae harvested either from logarithmic or stationary growth phase.

A weak induction of mifotic gene conversion and point reverse mutation was obtained when the incubations were performed using phosphate buffer. No genetic effect was observed when the incubations were performed using Tris‐HCl buffer.

The experiments with ⁵¹Cr radiotracer demonstrated that Cr³⁺ ion enters the yeast cells and binds to DNA even if the incubation mixture was performed with Tris HCl buffer. This behaviour could be due to the highest concentration of CrCl₃ that cause some damages to cytoplasmatic membrane.     

Study on phosphate uptake of the marine cyanophyte Synechococcus sp. NIBB 1071 in relation to oligotrophic environments in the open ocean

Inorganic phosphate (Pi) uptake by the marine cyanophyte Synechococcus sp. NIBB 1071 was studied using cells grown in an artificial seawater medium. The phosphate uptake was markedly enhanced in cells grown in the medium of low phosphate concentrations (phosphate-limited cells) than in cells grown in the phosphate-rich medium (phosphate-replete cells). The diagnosis of kinetics of instantaneous phosphate-uptake showed that V _max of the former was more than two orders of magnitude greater than that of the latter, and the k _m of the former was about 1/20 of that of the latter. The enhancement of the phosphate uptake was completed after a 40-h incubation of phosphate-replete cells in the phosphate-free medium. The activation was suppressed by chloramphenicol, an inhibitor of protein synthesis. The uptake developed in phosphate-limited cells was energy dependent and susceptive to osmotic shock, which suggests the involvement of a periplasmic phosphate-binding protein, analogous to that found in heterotrophic gram-negative eubacterial cells. The relationship between phosphate quota and growth rate, together with the kinetical data for phosphate uptake, predicted that ambient phosphate as low as 0.5 nM could support cell growth at a rate of one division per day. Results indicate that cells can grow rapidly even at phosphate concentrations as low as nanomolar levels. A possible regulatory mechanism of phosphate uptake in marine Synechococcus spp. is discussed in relation to a wide distribution of this picophytoplankton in the ocean environment. Received: 19 March 1997 / Accepted: 2 April 1997     

Adsorptive separation of phosphate oxyanion from aqueous solution using an inorganic adsorbent

Phosphate removal from aqueous solution was explored using granular ferric hydroxide (GFH) as an inorganic adsorbent. Adsorption, desorption and kinetic studies were conducted on laboratory scale to evaluate the performance of GFH as an adsorbent for low concentrations of phosphate solution. The effect of pH on adsorption was investigated, and phosphate uptake was shown to decrease with an increase in solution pH, with maximum removal seen to occur at pH 3. The experimental data best fit the Temkin isotherm at both pH 3 and 4. Uptake of phosphate by GFH follows second-order kinetics, with the small particle range (76–200 μm) removing phosphate from the solution more rapidly than the larger particle range (710–850 μm). The kinetic results suggest that intra-particle diffusion is an important factor in phosphate adsorption onto GFH. Thermodynamic parameters (ΔG°, ΔH°, ΔS°) were evaluated, and the results indicated that the adsorption process was endothermic and spontaneous. This study demonstrates that GFH has potential to be used as a cost-effective adsorbent for phosphate removal from aqueous solution.     

Some properties of calcium-activated adenosine triphosphatase from the hermatypic coralGalaxea fascicularis

Samples of the hermatypic coralGalaxea fascicularis were collected between April 1987 and April 1990 from coral reefs off Singapore (103 °45E; 1 °13N). Ca²⁺-activated adenosine triphosphatase (ATPase) activity was detected in the plasma-membrane-enriched heavy microsomal fraction ofG. fascicularis. The high affinity component hadKm andVmax values of 0.0021 mM and 0.050 µmol Pi mg^–1 protein min^–1, respectively; corresponding values for the low affinity component were 0.15 mM and 0.85 µmol mg^–1 protein min^–1. The activity of the high affinity component was inhibited 80 and 50%, respectively, by the anticalmodulin drugs calmidazolium and chlorpromazine. The low affinity component of the Ca²⁺-ATPase may represent activities of alkaline phosphatase, Ca²⁺-ATPase from membranes of mitochondria and endoplasmic reticulum, or calmodulin-dissociated plasma membrane Ca²⁺-ATPase resulting from the removal of Ca²⁺ by EDTA during the isolation process. The high affinity Ca²⁺-ATPase is probably the enzyme responsible for Ca²⁺ extrusion from the cells ofG. fascicularis. The high and low affinity components of this Ca²⁺-ATPase could use ATP and ADP as substrates. Maximum activities of both components were registered at pH 7 and at 45°C. Ruthenium red, a specific inhibitor of Ca²⁺-ATPase, inhibited the activities of the high and low affinity Ca²⁺-ATPase by 100 and 60%, respectively. Inhibition of the activities of both components was also observed with sulphydryl reagents (PCMB and mersalyl). However, DCMU, diamox, dinitrophenol, iodoacetate, fluoride, cyanide, ouabain, oligomycin B and L-phenylalanine had no effect on the enzyme activities.