Allozyme variation in a wild african elephant (Loxodonta africana) population from the Kruger National Park,South Africa

• 1.1. Blood, liver, heart, testis, skin, eye, muscle and kidney samples were obtained from elephants (Loxodonta africana) in the Kruger National Park during a culling programme in April 1992.
• 2.2. Gene products of 25 protein coding loci in L. africana were examined by horizontal starch-gel electrophoresis.
• 3.3. Eighteen protein coding loci (72%) displayed monomorphic gel banding patterns whereas only seven (28%) displayed polymorphic gel banding patterns.
• 4.4. Average heterozygosity values for adults, youngsters and the total population are respectively 0.058, 0.024 and 0.047.
• 5.5. Relative gene diversities within and between populations are 84% and 16% respectively.
• 6.6. Two population simulation programmes were utilized to predict the duration of the current variability present in this species, based on current genetic variation and gene transfer from one generation to the next.

     

Genetic variation in the nine rainbow trout (Oncorhynchus mykiss) populations in South Africa

• 1.1. Twenty-six protein coding loci in nine populations of rainbow trout, from different localities in South Africa, were analyzed by starch and polyacrylamide gel electrophoresis to estimate the amount of genetic diversity present.
• 2.2. Heterozygosity ranged between 0.0445 and 0.0745.
• 3.3. The relatively high heterozygosity levels are probably due to the historical mixing of strains, and the differences in heterozygosity indicate that the populations originate from different sources, each with different genetical characteristics.
• 4.4. Differences in phenotypic characters (i.e. growth) seem to relate to genotypic variation, whilst food conversion rate and survival performance results did not seem to relate to genotypic variation.

     

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.

     

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.

     

Effects of a purine inhibitor,allopurinol, on urate metabolism in the german cockroach,Blattella germanica L. (Dictyoptera: Blattellidae)

• 1.1. Adult male and female cockroaches (Blattella germanica) were maintained on a positive nitrogen balance diet (66% protein) containing various levels of allopurinol (0–3%) to determine the effects of allopurinol on urate synthesis and storage.
• 2.2. Each insect was injected with [¹⁴C]hypoxanthine and after 1 week was analyzed for whole-body hypoxanthine, xanthine and urate radiolabel.
• 3.3. There was a general trend of decreased whole-body radiolabel retention, radiolabeled body urates and total-body urate content in both sexes with increasing amounts of dietary allopurinol.
• 4.4. Virgin female adults were allowed to feed on diets containing 0, 25 and 66% protein plus 0.1% allopurinol and were injected with [¹⁴C]xanthine.
• 5.5. After 1 week radiolabel content in the whole-body xanthine and urate pools was determined.
• 6.6. Females on the 0% protein diets contained less radiolabel in the whole-body and body urates than those on either 25 or 66% protein diets.

     

Environmental and genetic influences on the thermal physiology of Rana sylvatica

• 1.1.|Intraspecific variation in the thermal physiology of Rana sylvatica was examined.
• 2.2.|Heat and cold tolerances of both adult and larval representatives were determined for animals representing populations from New York, Maryland, Kentucky, Ohio, Michigan and Canada.
• 3.3.|In general, frogs from more northern localities exhibited lower heat tolerances.
• 4.4.|There was no evidence of interpopulational differences in cold tolerance. Similar trends were revealed by larval testing.
• 5.5.|Interpopulational differences among laboratory-reared tadpoles suggests a strong genetic component to Rana sylvatica thermal physiology.

     

A thioredoxin from the extreme thermophilic Archaeon Sulfolobus solfataricus

• 1.1. A purification procedure for a thioredoxin from the extremophilic archaeon Sulfolobus solfataricus is described.
• 2.2. The thioredoxin is active in the dithiothreitol-dependent reduction of insulin disulfide bonds.
• 3.3. The thioredoxin is a monomer of 24,800 Da; it is an acidic protein with a pi of 4.5.
• 4.4. The protein is stable to heating for 3 hr at 90°C.
• 5.5. The amino acid composition of S. solfataricus thioredoxin is reported.

     

Biochemical and calorific content of deep-sea aspidochirotid holothurians from the northeast atlantic ocean

• 1.1. The organic composition of the body tissues of eight species of deep-sea aspidochirotid holothurian, collected between 500 and 4100m depth in the NE Atlantic Ocean, was obtained by the biochemical analysis of protein, lipid, carbohydrate and % ash.
• 2.2. The major organic class was protein with soluble lipid the major soluble fraction in the ovary. Carbohydrate values were consistently low.
• 3.3. The calorific value was significantly higher in the ovary than in the other tissues.
• 4.4. The total body calorific content for two selected species, Benthothuria funebris and Mesothuria lactea, was 25.62 and 26.24J/mg ash-free dry weight (AFDW).

     

Some hematological data from marsh harriers (Circus aeruginosus) in central spain

• 1.1. Hematocrit, total protein and glucose values were determined in blood samples from 19 marsh harriers (Circus aeruginosus), 10 males and nine females.
• 2.2. The different parameters were studied on the basis of the ranges described in other birds.
• 3.3. There was a significant correlation between weight and blood glucose level.

     

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.

     

Comparative study of hemoglobins from different Artemia populations. The influence of temperature on the oxygen equilibria

• 1.1. The P50 values of extracellular hemoglobin (Hb) of five Artemia populations from different geographical origin are affected by temperature.
• 2.2. The free oxygen binding energy is high for all the populations (ΔH between −34.7 and −56.2kj/mol).
• 3.3. A possible correlation between thermal sensitivity of Hb and the ambient temperature of the habitat must be considered very carefully.
• 4.4. The occurence of different quantities of Hb1 (αα chains) Hb2 (αβ chains) and Hb3 (ββ chains) in the different populations possibly influences thermal sensitivity.

     

The effect of eyestalk ablation on growth,haemolymph composition and gill Na+, K+-ATPase activity of Penaeus monodon juveniles

• 1.1. Eyestalk unablated and unilaterally ablated Penaeus monodon juveniles had survival rates after 5 months of 75–72.5 and 67.5–60%, respectively.
• 2.2. Unilaterally ablated shrimps had significantly higher (P < 0.05) growth rate than unablated shrimps.
• 3.3. Eyestalk-ablatement resulted in a decrease in the haemolymph sodium concentration and an increase in the potassium and calcium concentration of shrimps.
• 4.4. The osmolarity of haemolymph and total protein concentration of unablated shrimps were demonstrated to be higher than those of unilaterally ablated shrimps.
• 5.5. The eyestalk-ablated shrimps possess higher total ATPase and Na⁺,K⁺-ATPase activities in the gill than those of unablated shrimps.

     

Carcass proximate composition of juvenile white sturgeon (acipenser transmontanus)

• 1.1. Body wt, carcass wt, liver wt, gonad wt, total length, and carcass proximate compositions of 8- to 32-month-old cultured sturgeon were significantly affected (P < 0.05) by ages.
• 2.2. Correlation coefficients were significant between age and body wt (r = 0.96), carcass wt (r = 0.96), total length (r = 0.92), liver wt (r = 0.88), gonad wt (r = 0.76), gonadosomatic index (r = 0.52), carcass moisture (r = −0.93), crude protein (r = 0.62) and lipid (r = 0.57).
• 3.3. The carcass proximate compositions of cultured sturgeon were 72.1–79.4% moisture, 13.5–17.5% crude protein, 3.4–7.4% crude lipid, and 4.2–5.0% ash.
• 4.4. A high variability in the body measurements and carcass proximate compositions of some cultured sturgeon suggested high potential for genetic and nutrition improvements in culturing these fish in hatcheries.

     

Lipoxygenase of the thermophilic bacteria thermoactinomyces vulgaris—properties and study on the active site

• 1.1. A lipoxygenase activity was purified from Thermoactinomyces vulgaris and some of its properties were characterized.
• 2.2. The enzyme showed a temperature activity range of 40–55°C with still significant activity over 60°C.
• 3.3. The pH of activity on linoleic acid had a broad range with an optimum at pH 6.0 and a weaker one at pH 11.0.
• 4.4. On arachidonic acid the pattern was narrow bell-shaped with an optimum at pH 6.5.
• 5.5. The purified lipoxygenase from Th. vulgaris showed an apparent K_m of 1 mM and V_max of 0.84 μmol diene/min/mg protein.
• 6.6. It was inhibited by the oxidation products, 9-HPOD and 13-HPOD.
• 7.7. A 160,000 Da molecular weight of the enzyme was determined by molecular filtration. Methionine, tyrosine, tryptophan and cysteine are apparently involved in its activity.

     

In vitro substrate utilization for lipid synthesis in liver explants from hyperthyroid chickens

• 1.1. Indian River male broiler chickens growing from 7 to 28 days of age were fed diets containing 12, 18, 24 and 30% protein + 0 or 1 mg triiodothyronine (T₃)/kg of diet to study energetic costs of lipogenesis and the use of various substrates for in vitro lipogenesis.
• 2.2. De novo lipid and CO₂ production were determined in the presence of [1-¹⁴C]pyruvate, [2-¹⁴q]pyruvate, [3-¹⁴C]pyruvate, [2-¹⁴C]acetate and [U-¹⁴C]alanine.
• 3.3. Oxygen consumption was determined in mitochondrial preparations to estimate the energetic costs in expiants synthesizing lipid.
• 4.4. Radiolabeled CO₂ derived from [1-¹⁴C]pyruvate was used as an estimate of coenzyme A availability in liver expiants. Lipids derived from [2-¹⁴C]pyruvate, [2-¹⁴C]acetate and [U-¹⁴C]alanine estimate relative substrate efficiency.
• 5.5. Labeled CO₂ production from [1-¹⁴C]pyruvate was greatest in that group fed a 12% protein diet and least in the group fed a 30% protein diet.
• 6.6. In addition, T₃ increased CO₂ production from [1-¹⁴C]pyruvate.
• 7.7. The production of ¹⁴CO₂ from the second carbon of pyruvate or acetate was increased by T₃.
• 8.8. The low-protein diet (12% protein) increased (P <0.05) lipogenesis.
• 9.9. Adding T₃ to the diets decreased carbon flux into lipid from all substrates, but increased CO₂ production from all substrates without changing stage 3 and 4 respiration rates in mitochondrial preparations.
• 10.10. These observations imply that coenzyme A availability may have regulated de novo lipogenesis in the present study.
• 11.11. It was also concluded that previously noted effects of T₃ on intermediary metabolism may involve metabolic pathways that do not involve changes in mitochondrial function.

     

Growth and haematological response of sturgeon hybrids Russian sturgeon (Acipenser guldenstadti brandt) × beluga (Huso huso L.) to protein and lipid contents in the diet

• 1.1. Fingerlings of intergenious hybrid Russian sturgeon (Acipenser guldenstadti) × beluga (Huso huso) weighing 22 g reared in water with salinity 18 ppt were fed nine diets differing in protein and fat content.
• 2.2. The increase of dietary protein content (from 45 to 52%) improved the fingerlings growth rate, food and protein conversion efficiencies. No effect of further protein content increase to 60% was observed.
• 3.3. The increase of dietary fat content from 10 to 20% positively influenced all growth results.
• 4.4. The muscular lipid content increased following the increase in dietary fat due to accumulation of triacylglycerols.
• 5.5. Distinctive leucopenia in neutrophils and leucophilia in lymphocytes following dietary protein and fat content increase were observed.
• 6.6. It was concluded that within the analysed range of values the increase of dietary protein and lipid content improved the physiological status of sturgeon hybrid fingerlings.

     

A simple and reliable method for the purification of Pseudomonas aeruginosa phospholipase C produced in a high phosphate medium containing choline

• 1.1. Pseudomonas aeruginosa phospholipase C from culture supernatants of bacteria grown in high-P_i basal salt medium with choline, as the sole carbon and nitrogen source, was purified by precipitation with 70% saturation ammonium sulfate in the presence of celite.
• 2.2. The PLC activity was eluted of this mixture by the use of a reverse gradient of 70-0% ammonium sulfate.
• 3.3. The peak containing the PLC activity revealed a single protein after SDS-PAGE.
• 4.4. The method could also be applied to purify PLC produced in a low-P_i complex medium. The resultant preparation was not homogeneous.
• 5.5. The molecular weight for both PLC preparations was about 70 kDa.
• 6.6. Both PLC used phosphatydilcholine and sphingomyelin as substrates, displayed hemolytic activity an exhibited an apparent K_M of 25 mM for p-nitrophenylphosphorylcholine.
• 7.7. They were not inhibited by 1% sodium deoxycholate but were 30% inhibited by 1% Triton X-100.
• 8.8. 2% sodium dodecylsulfate and 1% tetradecyltrimethylammonium bromide inhibited the PLC from the HP_l-BSM plus choline but not the enzyme from the LP_l-CM.

     

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.

     

Heating and cooling rates of eastern diamondback rattlesnakes,Crotalus adamanteus

• 1.Establishing if and how organisms modulate temperature changes is an important component of understanding their thermal biology.
• 2.We used temperature-sensitive radio-transmitters to monitor heating and cooling rates between 5 and 35 °C of four Crotalus adamanteus in the laboratory.
• 3.We found no difference between heating and cooling rates in C. adamanteus. Additionally, rates of temperature change mirrored those of a biophysical model, further suggesting a lack of physiological thermoregulation.
• 4.Our findings contrast previously published studies that demonstrate active temperature control of similarly sized reptiles and demonstrate a need for more investigations of physiological thermoregulation in reptiles.

     

PCB effects on production of carbohydrates,lipids and proteins in marine diatom Phaeodactylum tricornutum

• 1.1. Aroclor 1254 had an influence on biochemical composition of phytoplankton Phaeodactylum tricornutum.
• 2.2. Total lipid content of Arocolor 1254 treated phytoplankton ranged from 90 to 40%, total carbohydrates from 5 to 50%, while protein content was almost unchanged.
• 3.3. The observed rapid and significant increase in lipid content (150%) within the first 24 hr could be ascribed to their protective role.