Characterization of histones from plutei larvae of the sea urchin Tetrapygus niger

• 1.1. Histones were isolated from plutei larvae of the sea urchin Tetrapygus niger and analysed electrophoretically. Individual histones were purified and their amino acid compositions were determined.
• 2.2. The electrophoretic analysis revealed that larval histones are microheterogeneous; H1 exhibits four subforms, the nucleosomal core histones H2A, H2B and H3 were resolved into three subforms each and H4 had two subforms.
• 3.3. The comparisons of the amino acid compositions of plutei larvae histones with data from the literature of homonimus late variants isolated from gastrulas of other sea urchin species, indicate that late histone variants are conserved proteins with a very slight degree of species specificity and with general features of classical histones.

     

Comparison of U-small nuclear RNA levels in tissues of the silkmoth,Bombyx mori

• 1.1. Tissue-specific abundance of the capped small RNAs in the silkmoth Bombyx mori was compared using preparative immunoprecipitation with anti-trimethylguanosine antibody.
• 2.2. The yields of total capped small RNAs from larval posterior silk gland, 1. early, 2. late in the fifth-instar, and 3. immortal ovarian-derived cells in culture, were determined to be 187, 50 and 218 ng, respectively, per mg of total cellular RNA.
• 3.3. Separation of immunoprecipitated RNAs by polycrylamide gel electrophoresis, followed by densitometric analysis of the bands, allowed the quantitation of individual capped molecules.
• 4.4. This analysis revealed tissue-specific patterns.
• 5.5.|The data indicate that the total abundance of capped small RNAs in Bombyx is highest in rapidly-dividing cells.

     

Purification and characterization of arylsulfatase from sea urchin (Hemicentrotus pulcherrimus) embryos

• 1.1. Arylsulfatase was extracted from sea urchin (Hemicentrotus pulcherrimus) plutei and purified to electrophoretical homogeneity by means of DEAE-cellulose, acetone fractionation and Sepharose CL-6B, successively.
• 2.2. The molecular weight of this enzyme was approx, 670,000. The molecular weight of a single subunit was approx. 63,000. The K_m value for p-nitrophenyl sulfate was 0.59 mM.
• 3.3. This enzyme was competitively inhibited by the sulfate ion and was classified as the type II arylsulfatase. The pH optimum was between 5.0 and 6.0.

     

Relative contribution of two mechanisms to post-stimulus hyperpolarization in leech retzius cells

• 1.1. In Retzius cells of the horse leech, Haemopis sanguisuga, intensive firing is followed by prolonged post-stimulus hyperpolarization (PSH) mediated by an increase in K-conductance and activation of the electrogenic sodium pump.
• 2.2. The recovery of membrane potential during PSH can be described by a biexponential model from which the relative contribution of the early and the late component to the peak amplitude of PSH may be calculated.
• 3.3. The time course of the calculated early component coincides with the time course of changes that occur in input membrane resistance during PSH.
• 4.4. The relative contribution of the late component increases linearly with an increase in stimulus duration. The rate constants of the two phases did not change with changes in stimulus duration.
• 5.5. It was concluded that the proposed model is useful for the estimation of the relative contribution and kinetics of two PSH mediating mechanisms (K-conductance increase and activation of an electrogenic sodium pump) in different experimental conditions.

     

Allozyme variation in a dimeric esterase of the oriental fruit fly,Dacus dorsalis (insecta: tephritidae), from peninsular malaysia

• 1.1. Seven natural populations of Dacus dorsalis were analyzed for a dimeric esterase by means of horizontal starch-gel electrophoresis.
• 2.2. The electrophoretic phenotypes were governed by nine codominant Est-D alleles.
• 3.3. The commonest allele in all seven population samples was Est-D¹⁰⁰ which encoded an electrophoretic band with intermediate mobility.
• 4.4. The distribution of EST-D phenotypes were in accordance with Hardy-Weinberg expectations.
• 5.5. There was no geographic variation in the distribution of Est-D alleles.

     

Subcellular localization of zinc in experimentally polluted tubifex tubifex (Annelida,Oligochaeta)

• 1.1. Localization of Zn (+ ⁶⁵Zn) has been examined within twelve subcellular fractions (derived from discontinuous sucrose gradients) of preincubated T. tubifex.
• 2.2. Zn was principally associated with the pellet (28% of total) and lowest density fraction (14%).
• 3.3. Pellet ultrastructure is composed of chloragosomes and epicuticle. Pellet Zn is localized within chloragosomes, X-ray microanalysis showing chloragosomal Zn concentration to exceed epiculticular Zn by a factor of thirty.
• 4.4. Biochemical and ultrastructural studies demonstrate that Zn is not appreciably bound to other cell constituents.
• 5.5. Chloragosomal localization of internalized Zn indicates a capacity for detoxification.

     

Electrophoretic characterization of a hybrid between Eretmochelys imbricata and Caretta caretta (Cheloniidae)

• 1.1. An intermediate morphotype between Eretmochelys imbricata and Caretta caretta was studied in Praia do Forte, Bahia, Brazil.
• 2.2. Three enzymatic systems were successfully analyzed: SOD, lactate dehydrogenase (LDH) and esterase (EST). Isoelectric focusing of total soluble proteins of muscle and transferrin were shown.
• 3.3. Esterase exhibited nine phenotype patterns, seven in C. caretta and one in the others morphotypes. SOD phenotypes were identical in the three morphotypes. Lactate dehydrogenase and transferrins were characteristic for each species.
• 4.4. Jaccard's measure of similarity was calculated and a phenogram with the three morphotypes were constructed using isoelectric focusing of total soluble proteins.

     

Effects of prolactin and methallibure on second metamorphosis and plasma androgens in male newts,Taricha granulosa

• 1.1.Male rough-skinned newts, Taricha granulosa, were injected during late spring with ovine prolactin and/or methallibure (ICI 33,828), a known inhibitor of gonadotropin release.
• 2.2. Methallibure injections, either alone or with prolactin, reduced androgen concentrations in the plasma, as measured by radioimmunoassay.
• 3.3. Exogenous prolactin injections failed to affect plasma androgen titers in intact newts at this season.
• 4.4. Saline-injected controls exhibited a diminution in tail fin height and water drive, preference for total submergence in water.
• 5.5. The decrease in tail fin height and water drive was inhibited by prolactin treatment and, to a lesser degree, by methallibure treatment, suggesting that methallibure stimulated an increase in endogenous prolactin.

     

Biochemical evidences for two sibling species of genus Myliobatis (chondrichthyes: myliobatidae) in South Brazil

• 1.1. Two morphotypes of Myliobatis from the demersal fishery off the Rio Grande (Brazil) were studied.
• 2.2. Thirty-two alleles were detected and resolved by 27 loci.
• 3.3. Nei's measure of genetic identity was 0.8306 and Thorpe's similarity was 0.6990. Mean heterozygosities observed were 0.1327 for the “DE” morphotype and 0.0409 for the “DL” morphotype.
• 4.4. Seven loci were fixed differently in the two taxa studied. This indicates the existence of a barrier to gene-flow between them, showing that both morphotypes belong to different species.
• 5.5. Jaccard's measure of similarity was calculated and a phenogram with the two morphotypes and M. freminvillii was constructed using isoelectric focusing of total soluble proteins. This showed a higher similarity between the two morphotypes of Myliobatis than M. freminvillii.

     

Changes in composition and proteolytic enzyme activities of artemia during early development

• 1.1. The proximate composition, total and free amino acids, and proteases of Artemia nauplii were determined during early development.
• 2.2. Moisture increased from 71.0% to 80.8%, crude protein decreased from 13.2% to 8.8%, crude fat and ash varied slightly.
• 3.3. The total amino acids decreased. Free amino acids changed in three patterns.
• 4.4. Trypsin, chymotrypsin, carboxypeptidase A, B and cathepsin B and C increased in activity. The activity of trypsin was lower, while cathepsin B and C were the highest.
• 5.5. The protease activities were maximal at pH 7.5 and 8.0, and at 45°C on casein.
• 6.6. The optimal pH for carboxypeptidase A was 4.0, for carboxypeptidase B was 4.5, for trypsin and chymotrypsin were 7.0–7.5. The protease(s) active at pH 9.0–9.5 were to be determined.

     

Effect of conjugation on the incorporation of glycine into Tetrahymena

• 1.1. Conjugation of Tetrahymena enhanced the incorporation of glycine into the nuclear fraction by 500%.
• 2.2. Incorporation of glycine into the microsomal supernatant was augmented by almost 500% by conjugation.
• 3.3. Mitochondrial incorporation was stimulated nearly 3-fold in the conjugating strains while the incorporation of glycine into the microsomes was enhanced approximately 2.5 times.
• 4.4. In the whole cell, glycine incorporation was increased nearly 2-fold by conjugation.
• 5.5. Strong nuclear involvement was indicated by elevated metabolic activity and incorporation of glycine into RNA and DNA.
• 6.6. Stimulation of the metabolism of Tetrahymena by cell communication suggests that the contents of a cell can have a synergistic effect on another cell.
• 7.7. Augmentation of the biosynthetic capacities of cells by fusion is a demonstration of the dominant role of the cell membrane in the regulation and control of cells.
• 8.8. Enhancement of biosynthesis of nuclear proteins in conjugating strains of cells indicates that fusion gives rise to the synthesis of new protein from previously existing protein or protein procursors.
• 9.9. The specific activities of the subcellular fractions after the incorporation of glycine into 2 separated starved strains of Tetrahymena followed the usual pattern of nucleus less than whole cells, whole cells less than mitochondria, mitochondria less than microsomes, but with the microsomal supernatant being much greater than that of the microsomes.

     

Seasonal changes of total lipids in the turtle Sternotherus odoratus

• 1.1. Seasonal variation in total lipids was examined in several body components of the turtle Sternotherus odoratus.
• 2.2. Carcass fat stores in both sexes were depleted during winter. Additionally, a decline in carcass lipids was associated with increases in gonadal mass.
• 3.3. Concentrations of liver lipids were maximal during August and minimal during winter.
• 4.4. Males showed little seasonal change in plasma lipid levels, whereas females had seasonal peaks temporally associated with ovarian development and carcass fat storage.
• 5.5. Ovarian concentrations of lipids were minimal after nesting and increased during fall.
• 6.6. Results suggest that S. odoratus uses stored fats both for reproduction and maintenance during winter.

     

Acetylcholinesterase in Apis mellifera head during post-embryonic development. Existence of a glycoinositol-anchored membrane form at eary pupal stages

• 1.1. Properties of acetylcholinesterase (AChE, EC 3.1.1.7) from Apis mellifera head were studied during pupal development and at the adult stage.
• 2.2. During post-embryonic development, tissue and specific activities were closely related and increased to reach a maximum value at emergence and at last pupal stage, respectively.
• 3.3. In adults, AChE activity was weaker in foragers than in emerging bees.
• 4.4. The membrane form occurred in adult bees as well as in pupae whereas the soluble enzyme only appeared from Pd pupal stage.
• 5.5. The proportion of soluble and membrane forms fluctuated during late development but, in all cases, the percentage of the soluble form remained less than 10% of total AChE activity.
• 6.6. At all post-embryonic stages, the membrane form was sensitive to the action of phosphatidylinositol-specific phospholipase C (PI-PLC) and was converted into a hydrophilic enzyme.
• 7.7. In adult bees, the sensitivity to PI-PLC depended on the season. In summer, about 60% of the membrane activity could be solubilized by PI-PLC vs only 5% in winter.
• 8.8. The sensitivity of AChE to pirimicarb varied with the developmental stage.
• 9.9. In foraging bees, AChE was more susceptible to pirimicarb than in emerging bees. This difference of sensitivity to carbamate was abolished after removal of the membrane anchor either by mild trypsin digestion of PI-PLC treatment.

     

Influence of temperature,rate of feeding and body weight on nitrogen metabolism of bream,Abramis brama L

• 1.1. Measurements of the rate of nitrogen consumption, total nitrogen and ammonia excretion and nitrogen absorption of bream, Abramis brama L. (body weight range 0.4–519 g wet wt) were made at 10, 15 and 20 C.
• 2.2. Fish were fed once daily on live zooplankton collected in Lake Balaton and cultured Tubifex sp. at 5–15% of their body weight.
• 3.3. Fish size and temperature had a combined effect on the rate of total nitrogen excretion. Total nitrogen excretion did not increase proportionally with an increase in consumption.
• 4.4. On average, 52–80% of the nitrogen consumed with food was excreted by bream.
• 5.5. The greatest part of total nitrogen excretion was ammonia and its proportion in the total ranged between 53 and 75%.
• 6.6. Temperature did not have any significant effect on the proportion of excreted ammonia and the rate of excreted total nitrogen was the only factor determining its proportion in the total.
• 7.7. The rate of nitrogen absorption of bream was surprisingly very high.

     

Na+-K+ ATPase and carbonic anhydrase activities in larvae,postlarvae and adults of the shrimp Penaeus japonicus (Decapoda,Penaeidea)

• 1.1. Activities of Na⁺-K⁺ ATPase and carbonic anhydrase were measured through the early post-embryonic development of Penaeusjaponicus. In adults, only the Na⁺-K⁺ ATPase activity was measured.
• 2.2. ATPase activity was variable in the successive development stages. From zero in nauplii, the activity slightly increased in zoeae, and rose sharply in mysis stages 2 and 3.
• 3.3. A further significant increase in activity was noted at the transition from late mysis to early postlarvae, concomitant with a change from the larval osmoconforming pattern of osmoregulation to the postlarval and adult hyper-hyporegulating pattern.
• 4.4. The activity of Na⁺-K⁺ ATPase, measured in isolated cephalothorax, increased from PL3 to PL4 to its maximum value in PL5; at this stage, osmoregulatory capacity was fully efficient.
• 5.5. In young stages of P. japonicus, the variations in Na⁺-K⁺ ATPase activity appear correlated with the development of osmoregulatory ultrastructures, and with osmoregulation and salinity tolerance.
• 6.6. These results are discussed with regard to their ecological and physiological implications.
• 7.7. In adults, the activity of Na⁺-K⁺ ATPase was high in gills and epipodites and no activity was detected in branchiostegites. These results are related to the ultrastructure of these organs.
• 8.8. The activity of carbonic anhydrase did not change significantly in larval and postlarval stages.
• 9.9. From these results, it is proposed that the effector sites of osmoregulation are located in branchiostegites, pleurae and epipodites in postlarvae, and in epipodites and mainly in gills in adults.

     

Purification and characterization of hatching enzyme of the pike (Esox lucius)

• 1.1. A choriolytic enzyme was isolated from the hatching medium of the pike, Esox lucius.
• 2.2. The enzyme is defined as hatching enzyme.
• 3.3. The molecular weight of the enzyme is 24,000.
• 4.4. The enzyme is a glycoprotein containing 2% carbohydrate.
• 5.5. Its isoelectric point is 6.5.
• 6.6. The pH optimum is around pH 8.
• 7.7. The enzyme molecule contains two disulfide bonds but no free cysteine.
• 8.8. Inhibitor studies and metal analysis show that the enzyme is a zinc-metalloprotease.

     

Metabolic rates of Calathus melanocephalus (L.) (coleoptera,carabidae) from alpine and lowland habitats (jeløy and finse,norway and drenthe,the netherlands)

• 1.1. Metabolic rates (ml O₂/mg/hr) of three geographically separated populations of the carabid beetle Calathus melanocephalus L. (Finse and Je 10y, Norway and Drenthe, The Netherlands) were measured and compared by ANCOVA.
• 2.2. No significant relationship (P > 0.05) between metabolic rates and body weight or sex of the animals were found.
• 3.3. Individuals mostly acclimated to low temperatures by increased metabolic rates and in the opposite direction to higher temperatures. Individuals collected in early summer also showed higher metabolic rates than those caught later in the autumn.
• 4.4. Contradicting the theory of metabolic cold adaptation, beetles from The Netherlands had the highest metabolic rates, beetles from Finse intermediate rates and beetles from Jeløy the lowest rates.
• 5.5. No significant relation were found between geographical origin of the beetles and their respective chill-coma temperature.

     

Locust vitellogenin receptor: an acidic glycoprotein with N- and O-linked oligosaccharides

• 1.1. The locust vitellogenin (VTG) receptor which is embedded in oocyte plasma membranes is a glycoprotein.
• 2.2. With various lectins oligosaccharide units have been identified, among them neuraminic acid linked to Gal or GalNAc, mannose chains, Gal linked to GalNAc or GlcNAc and fucose linked to GlcNAc.
• 3.3. With specific enzymes it could be shown that mannose and most other oligosaccharides are O-linked while others like fucose are N-linked.
• 4.4. Enzymatic removal of all O-linked carbohydrates resulted in a drop of the molecular mass of the receptor protein from 200,000 to 110,000.
• 5.5. A total of N- and O-linked oligosaccharides of 54% was calculated.
• 6.6. The isoelectric point of the receptor was found to be at pH 3.4 increasing slightly after removal of neuraminic acid.
• 7.7. Removal of neuraminic acids destroyed the binding ability for VTG.

     

Hemoglobin-containing cells of Neodasys (gastrotricha,chaetonotida)—II. Respiratory significance

• 1.1. The properties of the intracellular hemoglobin of Neodasys sp. are described and the utility of the hemoglobin in oxygen transport and storage is considered.
• 2.2. The hemoglobin is located in immobile cells which occupy 14% of the total body volume. Heme concentration in these cells was 18.5 mM and the oxygen p50 (in vivo) was approximately 1.0 mmHg.
• 3.3. It is argued that oxygen storage is the most likely function of Neodasys hemoglobin. A simple geometric argument indicates that body wall oxygen transport is not greatly improved by facilitation.
• 4.4. Respiratory function in Neodasys is compared with that in a related gastrotrich, Turbanella, which is morphologically similar and is sympatrie, but does not possess hemoglobin.

     

Lipid biosynthesis in amphibian oocyte and embryonic cell-free preparations

• 1.1. The utilization of [2-³H]glycerol-3-phosphate in the synthesis of lipids during early embryogenesis was studied in cell-free preparations from oocytes or embryos of Bufo arenarum Hensel
• 2.2. The precursor was incorporated in all stages of development up to gill circulation, which indicates that oocytes and embryos have the enzymatic machinery necessary to synthesize at least part of their own lipids.
• 3.3. A significant decrease in the labeling of most lipids took place after fertilization, especially in gastrulas, but at gill circulation lipid synthesis was highly stimulated.
• 4.4. The incorporation pattern is similar in unfertilized oocyte, fertilized oocyte and gastrulas, where phosphatidylglycerol has the highest amount of radioactivity. At gill circulation stage phosphatidylethanolamine and neutral lipid biosynthesis also became significant.
• 5.5. The results suggest a different regulation of the biosynthetic lipid routes through the appearance of new enzymes or modulators of preexisting enzymes during amphibian development.