Concentrations of metals in Luidia clathrata and Luidia senegalensis (echinodermata: asteroidea) in tampa bay and the nearshore gulf of mexico,florida

1. The concentrations of zinc in the pyloric caeca and body wall were c. 10-fold greater than lead and nickel and c. 100-fold greater than cadmium and silver.2. The concentration of metal in the pyloric caeca to that in the body wall was equal or significantly greater for cadmium, equal or significantly less for silver and zinc, and significantly less for lead and nickel.3. The profiles of the metal concentrations in the organs were site specific, but the concentrations in the pyloric caeca and body wall were usually greater in the populations in the Bay than those in the Gulf of Mexico.4. The concentrations of metals in the body wall were less in small than large L. clathrata, and in proximal than distal parts of the arms of L. senegalensis.     

Regenerative capacity and biochemical composition of the sea star Luidia clathrata (Say) (Echinodermata: Asteroidea) under conditions of near-future ocean acidification

The present study examines sublethal effects of near-future (year 2100) ocean acidification (OA) on regenerative capacity, biochemical composition, and behavior of the sea star Luidia clathrata, a predominant predator in sub-tropical soft-bottom habitats. Two groups of sea stars, each with two arms excised, were maintained on a formulated diet in seawater bubbled with air alone (pH 8.2, approximating a pCO₂ of 380 μatm) or with a controlled mixture of air/C0₂ (pH 7.8, approximating a pCO₂ of 780 μatm). Arm length, total body wet weight, and righting responses were measured weekly. After 97 days, a period of time sufficient for 80% arm regeneration, pyloric caecal indices, and protein, carbohydrate, lipid, and ash levels were determined for body wall and pyloric caecal tissues of intact and regenerating arms of individuals held in both seawater pH treatments. The present study indicates that predicted near-term levels of ocean acidification (seawater pH 7.8) do not significantly impact whole animal growth, arm regeneration rates, biochemical composition, or righting behavior in this common soft bottom sea star.     

Changes in protein, lipid, and carbohydrate content during starvation in the fresh-water limpetAncylus fluviatils (Basommatophora)

Summary The fresh-water limpetAncylus fluviatilis, living in European brooks, was found to have relatively greater carbohydrate and lipid fractions in winter than in summer. During starvation in the winter stage, lipid reserves are diminished first, followed by the carbohydrate reserves. Protein is degraded at nearly equal rates throughout the experiments. Specimens suffering from starvation are not found in the field during winter. Lipid reserves are mainly deposited in the midgut gland, whereas the carbohydrate reserves are distributed more equally among different tissues.A. fluviatilis must feed continuously during the winter period. The results are discussed in relation to data from other Basommatophora.     

The protein,lipid and carbohydrate composition of protein bodies from Lupinus angustifolius seeds

Protein bodies isolated from dehulled seeds of Lupinus angustifolius (cv New Zealand Bitter Blue) contained 73 % protein, of which 78 % were globul     

Characterization and inhibition kinetics of cadmium on cytoplasmic malate dehydrogenase from the pyloric caeca of Luidia clathrata (say) (echinodermata: asteroidea)

1. Cytoplasmic malate dehydrogenase (cMDH) was purified 200-fold.2. Disc gel electrophoresis showed a single major band of activity of cMDH.3. MDH in crude cytoplasmic extract was less sensitive to Cd²⁺ than purified cytoplasmic MDH.4. Purified cMDH had a Km of 0.14 mM OAA.5. Concentrations of Cd²⁺ of 0.312 mM significantly inhibited the cMDH.6. The inhibition by Cd²⁺ was completely reversed by 1.54 and partly reversed by 0.56 mM 2-mercaptoethanol.7. The inhibition by Cd²⁺ was non-competitive. Calculated Ki values are below those reported for Cd²⁺-imidazole and Cd²⁺-cysteine interactions, but above those reported for other Cd²⁺-thiol group interactions.     

Gonad growth in the sea urchin, Strongylocentrotus purpuratus (Stimpson) (echinodermata: Echinoidea) and the assumptions of gonad index methods

In central Oregon intertidal populations, the echinoid Strongylocentrotus purpuratus (Stimpson) first begins to produce mature gametes at a diameter of 25 mm during the second year of its life. All individuals above 40 mm in diameter have mature gametes during the mid-winter spawning season. Gonad size increases rapidly relative to body size until the animals are ≈45 mm in diameter and have a total dry weight of ≈ 15 g. The ratio of gonad to body size reaches its maximum in animals between 40 mm and 50 mm in diameter; thereafter the ratio drops slightly with increasing size. The curvilinear relation between gonad size and body size is not related to a relative difference in body proportions with size. Internal volume, height, and diameter increase linearly with size. Body proportions did not differ between the two populations studied. Differences between populations in the ratio of gonad to body size extend to all sizes in the populations and the direction but not the amount of the difference is consistent from year to year. These differences between habitats are probably related to food supply. The use of gonad ratio methods to normalize gonad size assumes that, within a given population, animals of different body size have the same ratio of gonad size to body size. This assumption is not correct for four species of sea urchins. Gonad index or ratio methods are useful for comparing animals of the same size through time within a population or from different habitats. Restriction of the size range of animals used and use of samples of sufficient size permit gonad ratios to be used to assess the capacity of different habitats to support gonad production in sea urchins and other animals.     

Changes in the yield, and carbohydrate, lipid and protein content of milk during lactation in the rat

The milk yield and composition was studied during the first three lactations of a group of rats. Milk yield increased steadily throughout the three lactations, but was somewhat lower during the first than subsequent lactations. Protein concentration was similar during all three lactations and varied little with stage of lactation. In contrast the lactose concentration, which was reasonably constant for the first 8 days post partum, increased thereafter two-fold by the end of the period studied in all three lactations. However, the N-acetyl-neuraminyl lactose concentration showed somewhat reciprocal changes. Considerable variations in the triacylglycerol concentration was found during the first lactation but few changes were observed during subsequent lactations. The free fatty acid concentration was at all times low and showed no significant changes during or between lactations. At most stages of lactation in raw milk, the major fatty acids are palmitate, oleate and linoleate. However, as lactation progresses there is an increase in the proportion of medium-chain saturated fatty acids and a corresponding decrease in the proportion of long chain unsaturated fatty acids in milk fat. Clearly the composition of milk is not invariable but changes both during and between lactations. Such changes may be expected to have some influence on the metabolism of the offspring.     

The annual pyloric cycle of Asterias rubens L. (echinodermata: Asteroidea)

Observations of biochemical changes in the pyloric caeca of Asterias rubens L. in different nutritional states and at different stages of the reproductive cycle show the existence of an annual cycle in the pyloric caeca. This pyloric cycle is closely related to that of the gonads. During the gonadal rest (May to September, when the gonads are barely visible) the pyloric caeca grow and store glycogen. During gonadal activity (October to April), they progressively autolyse and first accumulate, then liberate, lipid reserves. This winter pyloric autolysis provides the gonads with the structural material necessary for their annual growth. The summer pyloric growth must be interpreted as the accumulation of the structural material. Under normal conditions, during gonadal rest, the pyloric glycogen reserves ensure the survival of the animal. Pyloric lipid reserves appear only at the beginning of gonadal activity. Their synthesis is intimately related to the start of the gonadal activity of which they are the principal energy source. We believe that the pyloric cycle is under control of hormones that could be transported through the haemal system.The pyloric caeca are the only reserve organs of starfish. Neither the other digestive organs nor the body wall accumulate energy reserves. During starvation of medium duration (2 to 4 weeks) the pyloric caeca suffice to ensure the survival of the animal by liberating their reserve material and simultaneously starting to autolyse. During prolonged starvation, general autolysis occurs and the size of the starfish diminishes.     

Analysis of protein,carbohydrate and lipid in rotifers

Protein, carbohydrate and lipid amounts were determined for several rotifer species collected directly from the field. Brachionus calyciflorus was the most abundant species; therefore making possible more data for it. An increase in protein content of this species occurred when its concentration in food (µg protein/ml) also increased. Keratella tropica showed a similar pattern, but Asplanchna brightwelli did not.Carbohydrate proved to be the main form of storage in rotifers. In Brachionus calyciflorus females bearing no egg, 8% of the total biomass was carbohydrate; in females bearing one egg, 15% carbohydrate was found. Lipid does not appear to be used for storage since no increase in the amount of lipid was detected in females bearing eggs or embryos. This suggests that lipid has a structural function. Finally, a relationship between rotifer body volume and protein content at a given food concentration was obtained. The cladoceran Daphnia magna follows the same pattern.     

Variation in levels of lipid components and protein in ecogeographic races of Sorghum bicolor

Sorghum bicolor (L.) Moench is a widespread grass of the African savanna. It contains wild and cultivated subspecies which have morphologically distinct ecogeographic races. Measurements of the amount of oil and protein in sorghum grains revealed significant differences in protein levels between wild and cultivated subspecies. Measurements of the relative percentages of fatty acid components of oil also revealed significant differences in levels of oleic and linoleic acid among wild and cultivated races. We conclude that morphological differences acquired in the course of differentiation of ecogeographic races have been paralleled by differentiation in levels of lipid components and grain protein levels.     

Factors influencing swimming in bay scallops, Argopectenirradians (Lamarck, 1819)

Factors influencing the probability, distance, and direction of swimming in bay scallops (Argopectenirradions Lamarck, 1819) were studied through a series of experimental releases in the field and in a 3-m tank. The probability of a scallop swimming was significantly influenced by the type of substratum on which it was released (sand vs. grassbed), by contact with two natural gastropod predators (Murex, Fasciolaria), and by the amount of rest allowed after a previous swim. The horizontal distance traveled by a swimming scallop was significantly influenced by artificial weight of a magnitude equivalent to a normal load of shell-encrusting organisms, by the amount of rest allowed after a previous swim, by the height attained in the water column, and by the scallop's size. The direction of scallop swimming was significantly influenced by the location along the mantle edge where a predator was contacted, and by factors probably related to the asymmetrical water flow pattern through the mantle cavity. Swimming in bay scallops apparently serves to maintain position in grassbeds and to avoid predators.     

Seasonal variations in the total lipid content of Chorismus antarcticus (Pfeffer) (Crustacea: Decapoda) at South Georgia

The Antarctic benthic prawn Chorismus antarcticus (Pfeffer) was sampled regularly for a year and its total lipid content measured. Immature and transitional prawns had very variable lipid contents but similar mean values (2.92 and 2.91 % fresh wt, respectively); the variation was, in part, due to fluctuations in lipid reserves associated with ecdysis. Maturation of the testes involved the synthesis of ≈ 1.8 mg lipid, and female prawns synthesized an average of 50 % of their own lipid content for the gonad. Fecundity did not appear to be limited by the demand for egg lipid and synchrony in the breeding cycle was probably related to the planktonic feeding of the newly-hatched larvae. Eggs showed an unusual increase in total lipid content during the early stages of embryonic development, followed by the more normal decrease; larvae probably hatch with some reserve lipid.Available data on lipid contents of Antarctic crustaceans are briefly reviewed. The high lipid contents observed in herbivorous Antarctic planktonic crustaceans are due to the patterns of feeding imposed by the strongly seasonal nature of primary production in Antarctic waters, rather than low temperature per se. There is no evidence from the benthos of any systematic elevation of lipid content in polar species, although there is an indication of an increased lipid content in the muscle of polar crustaceans.     

Heat shock protein responses in thermally stressed bay scallops, Argopecten irradians, and sea scallops, Placopecten magellanicus

The effects of thermal stress on the induction of heat shock proteins (HSPs) were examined in northern bay scallops, Argopecten irradians irradians, a relatively heat tolerant estuarine species, and sea scallops, Placopecten magellanicus, a species residing in cooler, deeper water. Polyclonal antibodies used in this work for analysis of inducible HSP70 and HSP40 only recognized proteins of 72 and 40 kDa respectively from the mantles of both scallop species. Additionally, HSP quantification using the antibody to HSP70 was equally effective by either immunoprobing of western blots or ELISA, demonstrating that either approach could be successfully employed for analysis of thermal response in scallops. Sea scallop HSP70 and HSP40 did not change when animals were heat-shocked for 3 h by raising the temperature from 10 °C to 20 °C; however, a 24 h treatment of the same magnitude elicited a significant response. Conversely, bay scallops displayed rapid and prolonged HSP70 and HSP40 responses during the recovery period following a 3 h heat shock from 20 °C to 30 °C. Temperature reduction from 20 °C to 3 °C for 3 h also caused significant HSP70 and HSP40 increases in bay scallops; this represents the first time cold shock was shown to induce HSP synthesis in bivalve mollusks. The onset of the HSP40 response was more rapid than for HSP70, occurring at the end of the cold shock itself prior to transfer to a recovery temperature. Both proteins responded maximally during recovery at control temperature. HSP responses of sea and bay scallops to thermal stress may be related to their habitat in the natural environment and they suggest a differential capacity for adaptation to temperature change. This is an important consideration in assessing the response of these scallops to different culture conditions.     

Transbilayer (flip-flop) lipid motion and lipid scrambling in membranes

This paper reviews the current knowledge on the various mechanisms for transbilayer, or flip-flop, lipid motion in model and cell membranes, enzyme-assisted lipid transfer by flippases, floppases and scramblases is briefly discussed, while non-catalyzed lipid flip-flop is reviewed in more detail. Transbilayer lipid motion may occur as a result of the insertion of foreign molecules (detergents, lipids, or even proteins) in one of the membrane leaflets. It may also be the result of the enzymatic generation of lipids, e.g. diacylglycerol or ceramide, at one side of the membrane. Transbilayer motion rates decrease in the order diacylglycerol ? ceramide ? phospholipids. Ceramide, but not diacylglycerol, can induce transbilayer motion of other lipids, and bilayer scrambling. Transbilayer lipid diffusion and bilayer scrambling are defined as two conceptually and mechanistically different processes. The mechanism of scrambling appears to be related to local instabilities caused by the non-lamellar ceramide molecule, or by other molecules that exhibit a relatively slow flip-flop rate, when asymmetrically inserted or generated in one of the monolayers in a cell or model membrane.     

夏蜡梅及其主要伴生种叶的灰分含量和热值

分别于2006年7月、10月和2007年4月,对全光照、林缘和林下3种光环境下夏蜡梅及群落中35种主要植物叶的灰分含量和去灰分热值进行测定,分析它们在光合作用中对太阳能的固定和积累能力。不同光环境下夏蜡梅叶灰分含量的大小顺序都是全光照＞林缘＞林下,10月3种光环境下夏蜡梅叶灰分含量均高于4月和7月,均差异显著。4月、7月和10月,林下和全光照环境下的叶去灰分热值呈先下降后上升的趋势,而林缘中叶去灰分热值却逐渐下降。群落各层植物的灰分含量大小顺序为草本层＞灌木层＞间层＞乔木层,夏蜡梅灰分含量略低于灌木层灰分含量的平均值;各层次植物平均去灰分热值大小顺序为乔木层＞灌木层＞草本层＞间层,夏蜡梅平均去灰分热值低于间层。多数植物不同季节叶的灰分含量、去灰分热值均以10月最高。     

Protein,carbohydrate, and lipid levels of the adult body wall of Actinopyga agassizi,Synaptula hydriformis and Pentacta pygmaea (Echinodermata: Holothuroidea)

• 1.1. Levels of protein, carbohydrate, and total lipid (in percent dry weight of the body wall) are 18.6, 1.3 and 1.5% for Actinopyga agassizi; 28.1, 2.4 and 6.2% for Synaptula hydriformis; and 22.6, 0.9 and 1.5% for Pentacta pygmaea.
• 2.2. The body wall of a standard sized (142 g wet body wall weight) adult Actinopyga agassizi contains 5.0 g protein, 0.35 g carbohydrate, and 0.40 g lipid.
• 3.3. The large amount of organic material in the body wall suggests that it has great potential as a nutrient storage organ in holothuroids. The high levels of protein suggest that it would be the primary energy source during prolonged need.

     

Ovarian and fat body protein concentrations in Ips sexdentatus (Coleoptera: Scolytidae) parasitized by nematodes

The protein concentrations of fat body and ovaries in Ips sexdentatus either uninfected or infected by Parasitaphelenchus sp., P. sexdentati, or Contortylenchus diplogaster were measured at various stages of insect development, from preswarming maturation to the first oviposition (24 hr after mating). Weight variations of the fat body and ovaries in insects infected by C. diplogaster show the same evolution as those observed in uninfected insects, but at a much lower level. Fat body proteins in uninfected insects reach their minimum level during swarming, but they remain fairly constant throughout the maturation of the first egg. After dropping shortly after swarming, the ovarian protein level in such insects increases in two stages during ovarian maturation. The first stage, which corresponds to a slow protein incorporation, takes place during the first 12 hr after mating. During the second stage, i.e., beyond 12 hr, a significant level of proteins is rapidly incorporated into the ovaries. In insects infected by Parasitaphelenchus fat body proteins are reduced and protein incorporation into the ovaries is reduced; Parasitaphelenchus would thus affect at least some proteins required for ovarian maturation in their host. Fat body protein levels are even more affected by C. diplogaster than by Parasitaphelenchus, while incorporation into ovaries seems to be less affected in spite of slower ovarian growth. C. diplogaster might thus essentially act both upon proteins which are not required for the ovarian maturation of their host and upon nonproteinaceous substances that are required for such maturation. Results are discussed in relation to the possible mode of action of parasitic nematodes.     

Age-related changes in antioxidant enzyme activities, fatty acid composition and lipid peroxidation in whole body Gammarus locusta (Crustacea: Amphipoda)

The main aim of this work was to provide baseline data on aspects of pro-oxidant and antioxidant processes in different life-stages of the marine amphipod Gammarus locusta. The activities of antioxidant enzymes and levels of lipid peroxidation were determined in whole body juveniles, subadults, and male and female adults of a laboratory population of G. locusta. Fatty acid composition of individuals at these different stages of development was also characterised in order to examine the contribution that polyunsaturated fatty acids (PUFA) might make to the peroxidation status of animals. The antioxidant enzymes, measured in whole body 100,000 supernatants, comprised catalase (CAT, EC 1.11.1.6), superoxide dismutase (SOD; EC 1.15.1.1) and glutathione peroxidase (GPX; EC 1.11.1.9). Fatty acids were analysed as fatty acid methyl esters (FAME). Lipid peroxidation was examined in terms of the levels of lipid peroxides determined as thiobarbituric acid-reactive malondialdehyde equivalents. Age-related changes were seen in antioxidant enzyme status: levels of SOD (p<0.01) and GPX (p<0.001) activities decreased progressively during development from juveniles to adults. Sex-related changes in GPX activity were also seen, the levels being higher in adult males than females (p<0.001). The amount of FAME present in whole body amphipod also changed over the life span. Among PUFA, the eicosapentaenoic (C20:5n-3), arachidonic (C20:4n-6) and docosahexaenoic (C22:6n-3) were the most abundant acids in this species, and both their individual concentrations and total PUFA increased progressively with age (up to 3.3-fold; p<0.001). The latter changes may contribute to the explanation of the observed differences in peroxidation status of the animals with age; thus, levels of lipid peroxides increased up to 40% in adult males compared to other age-classes (p<0.01). Overall, the decline in antioxidant enzyme activities, coupled with increased levels of PUFA, as the individual grows older, may render the older animals more susceptible to lipid peroxidation and oxidative stress.