Calcium balance in premoult and post-moult Gammarus pulex (Amphipoda)

SUMMARY. Adult Gammarus pulex lose about 42% body calcium into solution over a 2–3-day period preceding the moult. A further 54% body calcium is lost with the exuviae, leaving c . 4% in the newly moulted animal.
Nearly all of the body calcium in a stage A (post moult) animal is contained in the hepatopancreas and a transient increase in the calcium content of this tissue is seen in some individuals. The haemolymph calcium compartment is heavily depleted at this stage. In stage B animals the hepatopancreas calcium level has returned to, or even fallen below, the intermoult level while the haemolymph calcium concentration remains lower than in intermoult animals.
Animals switch from a strongly negative calcium balance to a state of rapid calcium uptake immediately following moult. Uptake at 10°C proceeds at a rate of between 3 and 10 μmol g⁻¹ h⁻¹ depending on the calcium concentration of the external medium. The lower rate is found in starved animals in 0.1 mM calcium and this concentration is probably close to a minimum for the satisfactory restoration of body calcium. Recalcification is completed in 10–14 days in 0.1 mM calcium and is apparently enhanced by the presence of food in the form of a portion of oak leaf together with the cast exuviae. In 1.0 mM calcium the recalcification period is shortened to 3–4 days. This is considerably longer than the time recorded for French populations of this species (Vincent, 1969), although reasons for this are offered.     

Distribution of elements in the lily pollen tube tip,determined with the Oxford scanning proton microprobe

Summary Pollen tubes ofLilium longiflorum were fixed with glutaraldehyde and investigated unsectioned with the Oxford scanning proton microprobe (SPM). Two-dimensional maps which show the distribution and concentration of phosphorus, sulphur, chlorine, potassium, calcium, iron, copper, zinc and arsenic are presented. The maps show that, within the pollen tube tip region, calcium and zinc exhibit relatively steep longitudinal concentration gradients compared to the more flat distributions of phosphorus and sulphur. Chlorine, potassium, iron and copper appear equally distributed along the tube. All elements with the expception of arsenic show the highest concentration within the cell protoplasm and not in the cell wall. Additional signals of arsenic, chlorine and potassium originate from the remaining fixative dried around the tube, containing also the free ions of the cell. The arsenic signals originate exclusively from the buffer used during fixation. The different maps are compared and discussed in relation to their significance to the pollen tubes.Abbreviations EDAX energy dispersive analysis of X-rays - EIXE electron induced X-ray emission - PIXE proton induced X-ray emission - SPM scanning proton microprobe     

Changes in elemental composition of human chromosomes during a G-banding (ASG) and a C-banding (BSG) procedure.

Human chromosomes fixed in methanol-acetic acid have been examined by X-ray microanalysis, before, during and after a G-banding and a C-banding procedure. Phosphorus (representing mainly DNA), sulphur and calcium are the most prominent elements in untreated chromosomes. In the G-banding procedure, the calcium is lost during 2 x SSC treatment. In the C-banding procedure, calcium is lost in the preliminary HCl treatment. During the following barium hydroxide treatment a large amount of barium becomes attached to the chromosomes, but is lost again during the subsequent 2 x SSC treatment. In both banding techniques Giemsa staining produces large peaks for sulphur (thiazine dyes) and bromine (eosin), showing that both types of dyes are involved in the staining. Reduction in the phosphorus peak during these procedures may be partly due to extraction of DNA and other chromosomal components, but could also be due to absorption of phosphorus X-rays by heavy elements (barium and bromine).     

Calcium,phosphorus and adenylate levels and Na(+)-K(+)-ATPase activities of prawn,Macrobrachium nipponense,during the moult cycle

Changes in calcium and phosphorus concentrations, adenylate (AMP, ADP and ATP) levels, and ratios and ATPase activities of Macrobrachium nipponense were investigated during the moult cycle. Ca level in the exoskeleton was lowest in early postmoult (stage A), increasing at stages B and through intermoult (stage C) and peaking in premoult (stage D1 and D2). The P concentrations in the exoskeleton and muscle in late premoult and early postmoult stages were higher than those at other moult stages, and were lowest in the intermoult. Muscle adenylate energy charge (AEC) changed with moult stages, and was in agreement with the change in inorganic P level in the muscle. AEC may be a direct indicator of energy metabolic activity during the moult cycle. ATP/ADP and ATP/AMP ratios in premoult and postmoult stages were higher than that in intermoult stage. Na(+)-K(+)-ATPase activities of gills, muscles and hepatopancreatic of prawns were higher in early postmoult and late premoult animals, whereas they were lower in late postmoult, intermoult and early premoult animals. Gill residual ATPase activity was significantly higher in postmoult animals, while the peak value of hepatopancreatic residual ATPase activity appeared in intermoult stage.     

三疣梭子蟹蜕壳周期肝胰腺、外壳和鳃中钙含量的变化

研究测定了三疣梭子蟹蜕壳周期肝胰腺、鳃和外壳中的钙含量。结果显示,在不同时间,鳃中钙含量变化较小,各时间点差异不显著;蜕壳前期至蜕壳刚完成阶段三疣梭子蟹(软壳蟹)肝胰腺中钙含量最高,蜕壳后第4 d肝胰腺中钙含量最低。三疣梭子蟹外壳中钙含量随着外壳的硬化(钙化)逐渐增加,完全硬化后外壳中钙含量达到最高。研究表明,蜕壳后三疣梭子蟹肝胰腺中钙含量的降低与外壳的钙化之间具有关联性,肝胰腺在三疣梭子蟹蜕壳后钙的储存中起着重要作用,而鳃在钙离子储存中所起的作用可能小于钙转移的作用。     

Quantification of biomineralization: an in-vitro tissue culture system and microanalysis of calcium, phosphorus and trace elements by total-reflection X-ray fluorescence

An in-vitro tissue culture system with folded periostea of 17-day-old fetal chick calvaria was combined with analytical methods to achieve quantification of biomineralization. A scanning electron microscope with an energy-dispersive X-ray detector was applied to show the distribution of calcium, phosphorus and trace elements. Calcium and phosphorus were concentrated in the zone of the mineralized matrix. Strontium was distributed similar to calcium. Zinc was distributed equally in the soft tissue and the mineralized matrix. Total-reflection X-ray fluorescence was used for quantification. Thyroxine in high concentration reduces the calcium content of the samples. One week after incubation magnesiumchloride (1.8 mM) or zincchloride (.1 mM) were found to reduce the calcium content by 38% or 82%, respectively.     

The distribution of zinc, cadmium, lead and copper within the hepatopancreas of a woodlouse

The distribution of metals within the hepatopancreas of Oniscus asellus (Crustacea, Isopoda) from two uncontaminated sites, and two sites contaminated with zinc, cadmium and lead, has been studied by atomic absorption spectrophotometry, light microscopy, transmission and scanning electron microscopy and X-ray microanalysis. The hepatopancreas contains two types of intracellular granule. The first type, in the S cells, are spherical granules which contain copper, sulphur and calcium. In woodlice from contaminated sites, these ‘copper’ granules, also contain zinc, cadmium and lead. The second type, in the B cells, are flocculent deposits which contain iron. In woodlice from contaminated sites, these ‘iron’ granules also contain zinc and lead. Moribund woodlice from contaminated sites have large numbers of ‘copper’ and ‘iron’ granules in the hepatopancreas and a fine deposit of zinc and lead on the membranes of the cells. There are numerous microorganisms in close association with the microvillous border of the hepatopancreas of woodlice from all four sites. Within the microorganisms of Oniscus asellus from contaminated sites, there are deposits of material which contain zinc, lead, calcium and phosphorus ‘Copper’ and ‘iron’ granules could have evolved as storage sites for essential metals to be utilized when demand from the body exceeds uptake from the food. Woodlice in contaminated sites may be able to ‘detoxify’ potentially harmful amounts of essential and non-essential metals by storing them in a relatively insoluble form within these granules.     

Regulation of the elemental composition of the epididymal fluids in the tammar, Macropus eugenii

Micropuncture, microanalytical and microelectrode techniques were used to study electrochemical aspects of 7 elements and fluid in the ductuli efferents and ductus epididymidis of the tammar. Rete testis fluid was isosmotic with blood and had a lower pH. It also contained lower concentrations of bicarbonate, sodium, calcium, magnesium, phosphorus and sulphur and higher concentrations of potassium and chloride than blood. The luminal fluid was acidified further during passage through the sperm ducts and all of the elements which were studied moved in or out of the lumen, usually against an electrochemical gradient. The ductuli efferents reabsorbed 87% of the fluid leaving the testis without changing the intraluminal concentrations of sodium, potassium and calcium, but the concentrations of magnesium, phosphorus and sulphur increased. The caput epididymidis reabsorbed about half the fluid entering it: sodium concentrations decreased and those of potassium and phosphorus increased. There was also some fluid reabsorption and an increase in the values of potassium and phosphorus in the corpus epididymidis. There was little net transport of fluid in the cauda epididymidis; sodium, chloride, magnesium and phosphorus concentrations decreased and potassium values increased. Studies involving filtration through a dialysis membrane of blood and fluid from the rete testis and cauda epididymidis showed that, whilst some of the calcium, magnesium, phosphorus and sulphur was associated with high molecular weight compounds in blood, the association was not significant in the reproductive fluids.     

Inorganic elements in the adults of Ascaridia galli (Schrank, 1788)

Inorganic analysis of Ascaridia galli has shown the levels of sodium, potassium, copper, magnesium, calcium, zinc, iron, nitrogen, phosphorus, sulphur, chlorine and cobalt (expressed as percentage of dry weight) to be higher in females than in males.     

Lipid metabolism of the male crab Pachygrapsus marmoratus during the moulting cycle

The moult induces important variations in the concentrations and fatty acid composition of lipid classes during the moulting cycle of the male crab Pachygrapsus marmoratus. Phospholipids are the predominant lipid class. The high levels in total saturated fatty acids but also in oleic and palmitic acids result of the semi-terrestrial ethology of this grapsidae. The hepatopancreas presents the most notable variations in the lipid concentration during the moulting cycle. Transport of hepatopancreatic lipids through the hemolymph to the periphery occurs during the end of premolt, just before the new tissues constitution.     

An X-ray Microanalysis Study of the Salt Glands and Intracellular Calcium Crystals of Tamarix

X-ray microprobe analyses of the secreted salts from glandsof 20 Tamarix aphylla (L.) Karst trees growing in alluvial soilsin the north western district of Victoria, Australia, show thatthe glands secrete a variety of elements including calcium,magnesium and sulphur. However, sodium, potassium and chloride,common ions reported to be secreted predominantly in other studies,are present in relatively low amounts in the secreted salts.Calcium, the major cationic element in the secretory productof the gland, was not detected in the symplasm of the secretoryand collecting cells or in the vacuoles of the collecting cells.Some evidence indicates that silicon may be secreted by theglands but further corroboratory data are required. Our resultssupport previous suggestions that the glands of Tamarix havea low level of selectivity. Large, spherical aggregates of calcium crystals were observedin the vacuoles of the mesophyll cells and quantitative X-raymicroanalysis suggested that the chemical composition of thecrystalline aggregates was CaSO₄, 2H₂O. The predominant elementsin the vacuolar sap were magnesium and sulphur, probably presentas MgSO₄, whereas the major elements in the cytoplasm were potassium,sulphur and phosphorus. In Tamarix aphylla the calcium contentof the leaf appears to be regulated by both the secretion ofcalcium salts from the leaf and by intracellular calcificationin mesophyll cells.Copyright 1994, 1999 Academic Press X-ray microanalysis, Tamarix, salt gland, secretion, salts, ions, calcium crystals, compartmentation     

Functional Aspects of the Salt Glands of the Plumbaginaceae

X-ray microanalysis and diffuse reflectance infrared Fouriertransform spectrometry were used to determine the presence andratios of elements in salt secretions from salt glands of greenhouseand experimentally-manipulated leaves of five species of thePlumbaginaceae Sodium, magnesium, silica, sulphur, phosphorus,chloride, potassium, calcium and carbonate were detected insecretions of greenhouse-grown plants. The salt glands of excisedleaves challenged by solutions of KI, KCl, NaCl, Na₂SO₄, MgCl₂and MgSO₄ secreted principally the ions of the challenging solutions. Key words: Ion transport, secretion     

Observations on the Distribution of Mineral Elements in the Leaf of Wheat (Triticum aestivum L.), with Particular Reference to Silicon

Wheat (Triticum aestivum L. cv. Wheaton) plants were grown inwater culture or in soil. Basal leaves (B) were harvested after3 weeks from the water culture plants, while flag leaves werecollected from soil-grown material at the time of inflorescenceemergence (E0) and 7 d after emergence (E + 7). Mineral distributionin bulk frozen leaves was investigated using SEM and X-ray microanalysis.The elements detected were silicon, phosphorus, chlorine, sulphur,potassium and calcium. Potassium was present in all cell typesat all harvests, chlorine was almost entirely confined to theadaxial and abaxial epidermi, while sulphur was only rarelydetected in the E0 and E + 7 leaves. Phosphorus was presentat higher levels in the E + 7 leaves than in the B or E0 leaves.At the B harvest calcium was confined to the adaxial epidermalcells, but in the E0 and E + 7 leaves it was present in bothepidermi. Silicon was, initially, mainly detected in the abaxialepidermal cells, but in older (E + 7) leaves it was presentin both epidermi and in some internal tissues. Mineral transportwithin the leaf and ionic environment at silica deposition sitesare discussed. Wheat, Triticum aestivum L., leaf, mineral distribution, X-ray microanalysis, silicon, calcium     

Ecophysiological diversity of alpine populations of Gammarus lacustris in relation to environmental calcium

1. The contribution of environmental calcium to ecophysiological diversity among populations of Gammarus lacustris was investigated by comparing five alpine lakes in France.
2. Calcium concentrations in the water varied with substratum lithology, ranging from 6 mg L^–1 in lakes on crystalline (igneous) rocks to 32.7 mg L^–1 in lakes on limestone, and up to 248 mg L^–1 in a lake with a gypsum environment.
3. The duration of the moult cycle and mortality rate were compared between populations by means of field and in situ laboratory and translocation experiments on adult males. Animals from water with low calcium concentrations showed a significantly longer moult cycle and higher mortality rate than those from water with high calcium concentrations. A significant increase in the duration of the moult cycle was observed in animals translocated to water of lower calcium concentration and vice versa.
4. These results suggest the existence of different physiological races of G. lacustris with an ecophysiological plasticity of calcium metabolism narrower than that of river-dwelling gammarids such as G. fossarum. This may be a consequence of geographic isolation among lacustrine populations together with the relatively stable environmental parameters in lakes.     

Moult and basal metabolic costs in males of two subspecies of stonechats: the European Saxicola torquata rubicula and the East African S. t. axillaris

The circannual patterns in resting metabolic rate (RMR) of males of two subspecies of stonechats, the European Saxicola torquata rubicula and the East African S. t. axillaris, are compared. As the birds from the two subspecies were raised and kept under comparable laboratory conditions, differences in metabolic rate between the two subspecies had to be genetically determined. RMR peaked during moult in both subspecies. During the rest of the year RMR was fairly constant in both subspecies and assumed to reflect basal metabolic rate (BMR). African stonechats had a 22% lower mass specific BMR than European stonechats, which is thought to reflect a genetical physiological adaptation to the differences in environmental circumstances they experience in the field. A low BMR makes an animal more susceptible to cold. Hence, the relatively high plumage mass in the African compared to the European stonechat may be functionally linked to its relatively low BMR. Moult costs, calculated from the plumage masses and the differences in RMR inside and outside the moult period, tended to be higher in the European compared to the African stonechats. These data and an interspecific comparison of moult costs over various species of birds support the earlier notion by Lindström et al. (1993) that moult costs are more closely linked with BMR than with body mass or rate of moult. The relation between moult costs and BMR and the fact that the efficiency of moult is extremely low (3.8 and 6.4% for European and African stonechats, respectively) suggest that the maintenance of specific tissues necessary for moult is a large cost factor. Alternatively, impaired insulation during moult may necessitate an increased metabolic capacity which may be associated with an increased RMR.     

Studies on the egg shell (oviducal and oviposited) of Chelonia mydas L.

The outer calcified surface of the turtle egg shell consists primarily of crystalline aggregates of calcium carbonate in its aragonite form, together with a small amount (< 5 %) of calcitic material. The latter is first deposited to be followed by aragonite deposition.In the first instance, calcification occurs on the rims of discrete pits formed by the lateral deflection of the ends of soft shell membrane fibres. As crystal deposition continues these pits become filled in and eventually occluded.Micro- and X-ray diffraction analyses of the calcified layer indicate the presence of phosphorus and sulphur. The effects of these elements on the type of crystal deposited, (i.e., aragonite or calcite) is discussed.     

Plasma metabolites reflect seasonally changing metabolic processes in a long-distance migrant shorebird (Calidris canutus)

Migrant birds have tightly scheduled annual cycles consisting of several distinct life cycle (sub-)stages such as reproduction, migration, moult and overwintering, each of which have specific metabolic requirements (e.g., fattening during migration, protein build-up during moult). This study examines changes in fat and protein metabolism during the annual cycle of body mass and moult over 1.5 years in a captive flock of an arctic-breeding shorebird, the red knot Calidris canutus islandica. 2-5 h after food withdrawal, plasma uric acid levels were still decreasing and beta-hydroxy-butyrate levels were low, indicating prolonged catabolism of dietary protein, probably linked with a conversion into lipids. Such a late-resorptive state is achieved much earlier in passerines, but only after several days in penguins and, thus, seems to depend on meal size or mass-specific metabolic rate. Substages of body mass gain and high body mass were characterized by increased plasma triglyceride levels reflecting increased turnover of lipids, and low levels of the ketone body beta-hydroxy- butyrate, indicating that the bird is not short of glucose. The high uric acid levels during these substages indicated an increased breakdown of nutritional protein. During moult, plasma triglyceride levels were low, suggesting that lipids were less available than at other times of the year. It is concluded that plasma metabolite levels indicate the metabolic processes related to migratory fuelling and moult and the influence of exogeneous factors.     

Some essential nutrient elements in forest plants as related to species,plant part,season and location

Summary Natural vegetation common to the forested areas of Nova Scotia was sampled and analyzed for the nutrient elements calcium, phosphorus, cobalt, molybdenum, manganese, zinc and copper. Results showed considerable variation within and between species. Variations due to plant part, season and location of sampling also occurred but to a lesser degree. With the possible exception of molybdenum and copper, the elements are present in adequate quantities for normal nutrition. The average range of nutrient content for cobalt was found to be 0.09 to 0.44; molybdenum 0.01 to 0.32; zinc 13.0 to 91.0; manganese 44 to 594; copper 4.9 to 31.7 in terms of parts per million while calcium ranged from 0.36 to 1.11 per cent and phosphorus from 0.06 to 0.21 per cent. re]19750210     

Energy dispersive X-ray microanalysis of neurosecretory granules of mouse pituitary on fresh air-dried tissue spreads

Electron microscopy of fresh air dried spreads of unstained posterior lobe tissue from mouse pituitary disclosed neurosecretory granules. Each granule showed a seemingly homogeneous dense core surrounded by a halo and a bounding membrane. The area between granules in the cytoplasm was relatively well preserved. The energy dispersive X-ray microanalysis revealed peaks for sulfur, chlorine and potassium in two granules. The third granule displayed peaks for phosphorus and chlorine. These elements probably contribute to the high electron density of the granules. There was no peak for calcium, in contrast to the dense bodies of human blood platelets.     

The effect of iron supply on the yield and composition of leaves of tomato plants

Summary This paper describes a factorial experiment which was designed to elucidate the effect of total iron supply and rate of iron supply on the yield of tomato plants. Information was also obtained on the effect of iron supply and leaf age on the concentration of a number of nutrient elements in the leaf tissue.Increasing the total iron supply increases the yield, and the iron concentration in the leaves, while the manganese, phosphorus, sodium, calcium and magnesium decrease in concentration. The young leaves have a lower concentration of iron, manganese, potassium, sodium, calcium and magnesium than the older leaves, while the reverse is true of nitrogen and phosphorus. A slow rate of iron supply decreases the yield and sodium concentration in the leaves but increases the manganese and phosphorus concentrations.Interaction between total iron supply and leaf position affects the manganese, potassium, calcium and magnesium concentrations in the leaves, while the interaction between total-iron level and rate of iron supply affects the phosphorus and calcium concentration in the leaves.