Coral growth in high-nutrient,low-pH seawater: a case study of corals cultured at the Waikiki Aquarium,Honolulu, Hawaii

Fifty-seven species of hermatypic corals have been maintained and grown in high-nutrient seawater at the Waikiki Aquarium, Honolulu, Hawaii. In this study we document the chemical conditions of aquarium water in terms of dissolved nutrients and carbon. Aquarium water is characterized by concentrations of inorganic nutrients that are high relative to most natural reef ecosystems: SiO₃ 200 M; PO₄ 0.6 M; NO₃ 5 M; NH₄ 2 M. In contrast, concentrations of organic nutrients are lower than most tropical surface ocean waters: DOP 0.1 M and DON 4 M. The incoming well-water servicing the facility has low pH, crating over-saturation of carbon dioxide. The coral communities in aquaria took up inorganic nutrients and released organic nutrients. Rates of nutrient uptake into aquaria coral communities were similar to nutrient uptake by natural reef communities. Coral growth rates were near the upper rates reported from the field, demonstrating corals can and do flourish in relatively high-nutrient water. The growth of corals does not appear to be inhibited at concentrations of nitrogen up to 5 M. Statements implying that corals can only grow in low nutrient oligotrophic seawater are therefore oversimplifications of processes that govern growth of these organisms. Some basic guidelines are given for maintenance of coral communities in aquaria.     

Crassulacean acid metabolism in tropical dicotyledonous trees of the genusClusia

Summary The performance of crassulacean acid metabolism (CAM) by dicotyledonous trees of the genusClusia sampled at three sites in the state of Falcon in northern Venezuela is characterized.Clusia leaves have a somewhat succulent appearance. Unlike leaves of many other CAM plants, which are uniformly built up of very large isodiametric cells, there are distinct layers of palisade and spongy mesophyll, with individual cells being smaller. There is no specialized water storage tissue. ¹³C values indicate thatC. multiflora in the elfin-cloud forest on top of Cerro Santa Ana, at 800 m altitude, performs C₃ photosynthesis (¹³ –27.1). However,C. rosea in the tall cloud forest on Cerro Santa Ana (600m altitude), andC. rosea andC. alata in the dry forest on Serrania San Luis (900 m altitude) perform CAM (¹³C –14.1 to –19.2). InC. alta andC. rosea there were large day-night changes in the levels of malic and citric acids ranging from 63 to 240 mmol 1^–1 for malid acid and from 35 to 112 mmol 1^–1 for citric acid. The sum of the changes in malate and citrate levels accounts for the changes of titratable protons measured. With a day-night change of titratable protons of 768 mmol 1^–1 in one of the analyses,C. rosea showed the highest value yet encountered in a CAM plant. Oscillations of free sugars (fructose, glucose, sucrose) and of starch were also analysed in the CAM performingClusia species. Carbon skeletons of the precursors involved in nocturnal malate and citrate synthesis largely derive from free sugars and not from polyglucan. Unlike some other CAM plants, there is no clear and quantitative correlation between day-night changes of organic acid levels and cell sap osmolality.Dedicated to Professor Dr. Otto L. Lange on the occasion of his 60th birthday.     

Conditions for high frequency embryogenesis from orange (Citrus sinensis Osb.) protoplasts

Using Trovita orange (Citrus sinensis Osb.) protoplasts isolated from 6-year-old nucellar callus, the effects of protoplast density and mannitol concentration on cell divisions and embryoid formation were examined.Somatic embryogenesis in nearly direct manner was observed only at a combination of low cell densities (4×10⁴/ml) and low mannitol concentrations (0.4 M). Two alternatives to achieve high frequency embryogenesis (70%) were to either dilute the cells to lower densities, or to do serial transfers of cells to fresh medium.Orange protoplasts (cells) showed embryogenic potential, and repression of embryogenesis occurred when protoplasts were cultured at a high density and/or under high osmotic pressure.     

Physiological ecology of Juniperus virginiana in oldfields

Juniperus virginiana plants grow faster than other associated tree species in abandoned fields. During the summer the needles of the species do not light saturate even at 1,750 E m^-2 s^-1, reach optimum photosynthesis at 20°C, and maintain maximum photosynthesis at-8 to-12 bar twig water potential. In the field, the plants experience pronounced daily changes in water potential. The magnitude of the changes becomes more pronounced later in the summer. Leaves of the mature plants have highest rate of photosynthesis, young trees intermediate, and seedlings lowest. In winter there is a slight shift in optimum temperature for photosynthesis and the plants photosynthesize at 0°C. The rates of photosynthesis are lower in winter than in summer. On sunny days with calm winds, mature individuals and seedlings maintain significantly higher temperatures than air temperature while intermediate plants do not. The latter exhibit a lower photosynthetic rate than both mature plants and seedlings. The trends of photosynthesis, in the 3 size classes, both in winter and summer, correspond to the chlorophyll content of their leaves. It is concluded that J. virginiana grows well in open field habitats because it is a sun-adapted, drought resistant species with a long growing season which includes winter. The species is excluded from mature forests because it is shade-intolerant.     

Absolute measurement of cell expansion in plant cell suspension cultures

A method is described for the measurement of intracellular volume (V_i) in cell cultures. In principle, any stable compound that neither penetrates the plasma membrane nor binds to the cells can be used to trace the total extracellular (apoplastic) volume and hence to estimate the intracellular volume. No suitable coloured or UV-absorbing compound could be found among those tested; the main problems were binding to the cell surface and/or instability in the medium. However, [¹⁴C]mannitol was an acceptable apoplastic marker, by use of which we showed that 21–47% of total packed cell volume (PCV) was intracellular, and 14–33% of total settled cell volume (SCV) was intracellular. Therefore, measurements of PCV and SCV misrepresent cell expansion to a variable extent. Cultures of Acer, Rosa, Spinacia and Zea achieved final symplastic volumes of only 9, 14, 6 and 6%, respectively, of the total suspension culture volume.     

Pheromone puffs suppress mating by Plodia interpunctella and Sitotroga cerealella in an infested corn store

The efficacy of pheromone mating disruption was investigated in a 7×6×3 m corn storage room harboring a high population density of Indian meal moth, Plodia interpunctella (Hübner) and Angoumois grain moth, Sitotroga cerealella (Olivier). Pheromones were released from a controlled release dispenser, the metered semiochemical timed release system (MSTRS^TM) at emission rates of 0.6 g min^–1 (Z9,E12:14:Ac for Indian meal moth) and 0.2 g min^–1 (Z7,E11-16:Ac for Angouimois grain moth). Mating disruption efficacy was evaluated using three parameters: male capture in pheromone traps, visual examination of mating behavior, and the incidence and frequency of mating as measured by spermatophores. In three trials, comparisons were made between data collected before pheromone treatment and during treatment. Disruption of pheromone source location by males averaged 70% and 40% for P. interpunctella and S. cerealella, respectively, in the three trials. In addition, reduced levels of copulation by both species were recorded during pheromone treatment. More importantly, significant reductions were recorded in the incidence and frequency of mating by females of both species collected during the treatment period. While 85% of P. interpunctella females collected before pheromone treatment in three trials had mated at least once, only 50% of the females collected during treatment had mated. The mean number of matings, as measured by spermatophores, ranged between 0.8–1.1 and 0.5–0.7 before and during pheromone treatment, respectively. Similarly, a 20–30% reduction in the proportion of mated S. cerealella females was recorded during pheromone treatment. In the three trials, mean number of spermatophores per S. cerealella female averaged 1.0 and 0.7 during the pretreatment and treatment periods, respectively. Additional tests conducted in small boxes also recorded significant mating disruption of both species.     

GTPγS-induced calcium transients and exocytosis in human neutrophils

Exocytosis and intracellular free calcium ([Ca²⁺]_in) were simultaneously recorded in single human neutrophils using patch-clamp capacitance measurements and the fura-2 fluorescence ratio method. Intracellular application of guanosine-5-O(3-thiotriphosphate) (GTPS) stimulates both exocytosis and a calcium transient. The calcium transient starts to develop after a lag phase of 40s and normally appears to trigger the onset of exocytosis indicated by the beginning of the capacitance increase. After this delay [Ca²⁺]_in increases from 150 nM to 600 nM with a sigmoidal time course. The peak concentration is reached within 30 s but the main increase occurs during 3s. [Ca²⁺]_in subsequently decays within 1–2 min to a level which is close to the resting value. This calcium transient is due to calcium release from inositoltrisphosphate-sensitive intracellular stores. Exocytosis also occurs if the calcium transient is abolished by intracellular EGTA but the lag phase is markedly prolonged. The GTPS-induced calcium transient is very similar to that observed after stimulation with N-formyl-methionyl-leucyl-phenylalanine. The interplay between guanine nucleotides, [Ca²⁺]_in and exocytosis in neutrophils closely resembles previous results obtained in mast cells suggesting a similar regulation of exocytosis in both cell types.     

Geochemical controls for Al, Fe, Mn, Cd, Cu, Pb, and Zn during experimental acidification and recovery of Little Rock Lake, WI, USA

Concentrations of Al, Fe, Mn, Cd, Cu, Pb, and Zn were measured in thereference and treatment basins of Little Rock Lake (Vilas County, Wisconsin), alow-alkalinity, seepage system (pH 6.1, alkalinity25eq/L) during six years of a whole-basinacidificationand the first four years of the lake's recovery. The treatment basin wasacidified with H₂SO₄ in three two-year steps to pH5.6, 5.1, and 4.7. By the end of year 4 of recovery, treatmentbasin pH increased to 5.3 as a result of internal alkalinity generation.During acidification, dissolved Mn and Fe (0.4mpore-size filters) increased at pH 5.6; dissolved Al, Cd, and Zn becameelevated at pH 5.1; and dissolved Pb at pH 4.7. Dissolved Cu remainedsimilar in both basins to pH 4.7. Al, Fe and Mn levels declinedsignificantly during the recovery period, approaching values at pH 5.3intermediate between the concentrations at pH 5.6 and 5.1 during acidification.Dissolved Al and Fe in the reference basin were near the equilibrium levels forsolubility of gibbsite (Al(OH)₃) and amorphousFe(OH)₃(s).The acidified basin was undersaturated relative to gibbsite, and dissolved Alwas limited by pH disequilibrium between the water column and sediments andpossibly by Al-DOC precipitation. Dissolved Fe apparently was controlled bysolubility of amorphous Fe(OH)₃(s) and Fe-DOC precipitation.Dissolved Mn levels in both basins were consistent with manganite[-MnOOH(s)] solubility. Elevated levels of Cd, Pb, and Zn in thetreatment basin during acidification probably resulted from less efficientscavenging of atmospherically-deposited Cd, Pb, and Zn by settling particles.     

Efficient secretion of human lysozyme from the yeast, <Emphasis Type="Italic">Kluyveromyces lactis</Emphasis>

Efficient secretion of human lysozyme from the yeast, Kluyveromyces lactis, was achieved by using more stable vectors in the order of S11 replication origin-containing episomal vector < full-length K. lactis plasmid pKD1-containing vector < centromeric vector < chromosome-integrated vectors. Cells containing a PGK (phosphoglycerate kinase) promoter-driven integration vector grown in non-selective rich medium achieved the highest level of secretion, 100 g lysozyme secretion ml ^–1 culture: this level was 10-fold higher than that achieved by episomal vectors. An additional copy of the protein disulfide isomerase gene further facilitated the secretion.     

Immunoreactivity of the corpuscles of Stannius of the garpike,Lepisosteus osseus,to antisera against salmon and trout stanniocalcins

Stanniocalcin-immunoreactive cells were localized in the corpuscles of Stannius of a holostean fish, the garpike (Lepisosteus osseus), using antisera against salmon and trout stanniocalcins and the peroxidase-antiperoxidase and protein A-gold immunohistochemical methods. The stanniocalcin-immunoreactive cells were periodic acid-Schiff-positive, and antibody staining was abolished if the antiserum was preabsorbed with corpuscle homogenate. Immunocytochemistry revealed two reactive cell types in the glandular parenchyma, and immunoreactivity was confined to the secretory granules. Staining of the granules was also abolished when the antisera were blocked with crude corpuscle homogenate. When corpuscle extracts from garpike were subjected to sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blot analysis, a single dense band was evident with a molecular weight of 68 kDa under non-reducing conditions, whereas three bands were observed (29, 31, and 34 kDa) under reducing conditions. Staining of all bands disappeared following preabsorption of the antiserum with salmon stanniocalcin, trout stanniocalcin, or garpike corpuscle extract. The results are compared with stanniocalcins from another extant holostean, the bowfin (Amia calva), and from more modern bony fishes, the teleosts.     

Use of single heart cells from chick embryos for the Na+ current measurements

To record the fast Na⁺ current, spheroidal heart cells enzymatically-dispersed from 3 18-day-old chick embryos were used for voltage clamping. The peak of currents in response to voltage steps of 200 ms long from holding potentials of -90 -105 mV were measured. The current-voltage curves for the peak inward current showed U-shaped relations; the averaged peak current of about -1400 pA was observed at about -30 mV and the current reversed sign at +40 + 50 mV. Both the peak current and the reversal potential values showed marked [Na]_o- dependence, i.e. reduced by 36% and by 20 mV, respectively, for a halved [Na]_o. Tetrodotoxin (TTX) partially (10^-6 M) or completely (10^-5 M) suppressed the current. The steady-state inactivation of the current (h) was characterized by the half inactivation voltage of around -80 mV and the slope factor of -4 -8 mV. The half activation voltage and the slope factor for the steady-state activation (m) were -55 mV and 4-6 mV, respectively. The electrophysiological and pharmacological properties were similar between young (3-day-old) and old (15-18-day-old) embryonic heart cells, excepting the much smaller current and the slower onset of TTX action in young embryonic hearts.     

Endothelin-1 and insulin induce cellular inactivation of protein kinase FA/glycogen synthase kinase-3α in a common signaling pathway

In this study, we investigate the effects of endothelin-1 (ET-1) and insulin on the cellular activity of protein kinase F_A/glycogen synthase kinase-3 (kinase F_A/GSK-3) in rat adipocytes. The cellular activity of kinase F_A/GSK-3 is inhibited to 50% of control within 30 min when cells are treated with 1 nM ET-1 at 37°C; in addition, significant inhibition to 60% of control is observed at as low as 1 pM ET-1. Conversely, ET-1 at concentrations up to 1 nM has no direct effect on purified kinase F_A/GSK-3 in vitro. Immunoblotting analysis further reveals that the protein level of this kinase is not significantly changed when treated with 1 nM ET-1 for 30 min. Similar to ET-1, insulin as low as 10 nM can also induce inactivation of kinase F_A/GSK-3 to 50% of control in adipocytes when processed under identical conditions. Most importantly, when treated with both insulin and ET-1, the activity of kinase F_A/GSK-3 can be decreased only to 50% of control. Taken together, the results provide initial evidence that ET-1 and insulin may regulate this important multisubstrate/multifunctional protein kinase in a common signaling pathway in cells.     

Effect of PPX1 inactivation on the exopolyphosphatase spectra in cytosol and mitochondria of the yeast Saccharomyces cerevisiae

Inactivation of PPX1 encoding exopolyphosphatase PPX1 in Saccharomyces cerevisiae results in a change in the exopolyphosphatase spectrum in the yeast cells. In the PPX1-deficient strain, elimination of an 45 kD exopolyphosphatase is observed in the cytosol, and activity of an exopolyphosphatase with molecular mass of 830 kD increases fivefold. The latter activity differs greatly in properties from the low-molecular-mass enzyme of the parent strain. In the soluble fraction of the mutant mitochondria, exopolyphosphatase of 45 kD characteristic of the soluble mitochondrial fraction in the parent strain is eliminated, and exopolyphosphatase with a molecular mass of 440 to 830 kD is found. On PPX1 inactivation, a membrane-bound form of mitochondrial exopolyphosphatase is unaffected in its activity level and properties. Therefore, the membrane-bound exopolyphosphatase of mitochondria and the high-molecular-mass enzyme of the cytosol of S. cerevisiae are not encoded by the PPX1 gene, unlike the soluble low-molecular-mass exopolyphosphatase of mitochondria, which is probably a product of this gene with a posttranslational modification. In the PPX1 mutant, exopolyphosphatase properties in the cell as a whole undergo modifications including the ability to hydrolyze polyphosphates (polyP) with different polymer degree.     

The Effect of Salicylic Acid on Peroxidase Activity in Wheat Calli Cocultured with the Bunt Pathogen Tilletia caries

The effect of salicylic acid (SA) on peroxidase activity in wheat (Triticum aestivum L.) calli cocultured with the bunt pathogen Tilletia caries was studied. Fungal infection was shown to activate cytoplasmic peroxidase. SA suppressed total peroxidase activity but did not inhibit the peroxidase with pI 9.8. A novel chitin-specific peroxidase with pI 3.5 appeared after the SA treatment. The infection of SA-treated cells with Tilletia caries activated the isoenzymes with pI 3.5, 4.8, and 7.5 and stimulated their secretion into the culture medium. The ability of SA to control wheat peroxidase activity during pathogenesis is discussed. The important role of this control in plant defense responses to the bunt pathogen is emphasized.     

Mismatch-specific DNA breakdown in nuclear extract from tobacco (Nicotiana tabacum) callus

Mismatch-specific enzymatic activity was sought for in nuclei from normal and transformed plant cells originating from tobacco (Nicotiana tabacum) callus and crown gall tumor induced by Agrobacterium tumefaciens. The specific enzymatic activity was assayed with substrates derived from synthetic oligonucleotides (19-mer sequences corresponding to the human K-ras gene). Single-base changes in the middle of the sequence were the basis for creating heteroduplexes with all eight mismatches. Homo- and heteroduplexes were ligated in a size ladder and used as substrates. We detected mismatch-specific DNA breakdown and determined basic requirements for the reations. Kinetic analysis indicates the following reactivity order of preference: C : A=C : C=C : T>G : TA : AG : AG : GT : T>>G : C. It can be said now that specific mismatch recognition and repair activities have been detected in all kingdoms of living species.     

Freeze-fracture studies on the cockroach hemocyte membrane complex: Symmetric and asymmetric membrane particle distributions

Summary Freeze-fracture studies were conducted on the membranes of normal cockroach hemocytes. The plasmalemma is asymmetric with the A fracture face containing 80–100 Å membrane intercalated particles at a concentration of 2500/². The B fracture face contains 120–150 Å particles with a relatively low density (800/²). The nuclear envelope displays an asymmetry with the A fracture face containing 1500 particles/² and the B face containing 300/ ². No significant particle size differences were observed in nuclear envelope fracture faces. Two types of symmetric membranes were also found in these cells. Both A and B fracture faces of the membrane surrounding the numerous cytoplasmic inclusion bodies contain particle sizes and concentrations similar to the B face of the plasmalemma. A second type of symmetry was observed in cells apparently engaged in exocytosis. Vesicles (0.1 D) from this process were completely particle free on both fracture faces. Such particle free vesicles could be found in the cytoplasm, attached to the plasmalemma, or completely separated from the cell.Supported by a Pharmaceutical Manufacturers Association Foundation Fellowship.The author wishes to thank Ms. Annalena K. Charla for assistance in plate preparation, Dr. Julius Schultz and the Papanicolaou Cancer Research Institute for use of the freeze-etch device, and Dr. David Smith for the electron microscope facilities.     

Identification of a specific protein in the mitochondrial fraction of the rat heart whose phosphorylation is inhibited by taurine

Summary It was previously reported that the mitochondrial fraction of the rat heart contained a specific protein with a molecular weight of approximately 44kDa whose phosphorylation was inhibited by taurine (Lombardini,1994a). Isolation of the 44kDa phosphoprotein on a 1-dimensional polyacrylamide gel using traditional glycine buffers followed by re-electrophoresing the cut out proportion of the gel which corresponds to the 44kDa protein on a tricine-buffered gel resulted in sufficient pure protein for sequence analysis. The results indicate that the 44kDa phosphoprotein is pyruvate dehydrogenase.     

Lipase-mediated homotopic and heterotopic double resolutions of a planar chiral organometallic alcohol

Summary (±)-Tricarbonyl ⁶-3-methylbenzyl alcohol)chromium was resolved to of 100%e.e. and of 92%e.e. by lipase-catalyzed transesterifications arranged in homotopic and heterotopic double resolutions.     

Nucleotide sequence and expression of the two genes encoding D2 protein and the single gene encoding the CP43 protein of Photosystem II in the cyanobacterium synechococcus sp. PCC 7002

The unicellular photoheterotrophic cyanobacterium Synechococcus sp. PCC 7002 was shown to encode two genes for the Photosystem II reaction center core protein D2 and one gene for the reaction center chlorophyhll-binding protein CP43. These three genes were cloned and their DNA sequences determined along with their flanking DNA sequences. Northern hybridization experiments show that both genes which encode D2, psbD1 and psbD2, are expressed at roughly equivalent levels. For each of the two psbD genes, there are 18 nucleotide differences among the 1059 nucleotides which are translated. The DNA sequences surrounding the coding sequences are nearly 70% divergent. Despite the DNA sequence differences in the genes, the proteins encoded by the two genes are predicted to be identical. The proteins encoded by psbD1 and psbD2 are 92% homologous to other sequenced cyanobacterial psbD genes and 86% homologous to sequenced chloroplast-encoded psbD genes.The single gene for CP43, psbC, overlaps the 3 end of psbD1 and is co-transcribed with it. Results from previous sequencing of psbC genes encoded by chloroplasts suggest that the 5 end of the psbC gene overlaps the 3 end of the coding sequence of psbD by 50 nucleotides. In Synechococcus sp. PCC 7002, the methionine codon previously proposed to be the start codon for psbC is replaced by an ACG (threonine) codon. We propose an alternative start for the psbC gene at a GTG codon 36 nucleotides downstream from the threonine codon. This GTG codon is preceded by a consensus E. coli-like ribosome binding sequence. Both the GTG start codon and its preceding ribosome binding sequence are conserved in all psbC genes sequenced from cyanobacteria and chloroplasts. This suggests that all psbC genes start at this alternative GTG codon. Based on this alternative start codon, the gene product is 85% identical to other cyanobacterial psbC gene products and 77% identical to eucaryotic chloroplast-encoded psbC gene products.     

Passive ionic properties of frog retinal pigment epithelium

Summary The isolated pigment epithelium and choroid of frog was mounted in a chamber so that the apical surfaces of the epithelial cells and the choroid were exposed to separate solutions. The apical membrane of these cells was penetrated with microelectrodes and the mean apical membrane potential was –88 mV. The basal membrane potential was depolarized by the amount of the transepithelial potential (8–20mV). Changes in apical and basal cell membrane voltage were produced by changing ion concentrations on one or both sides of the tissue. Although these voltage changes were altered by shunting and changes in membrane resistance, it was possible to estimate apical and basal cell membrane and shunt resistance, and the relative ionic conductanceT _i of each membrane. For the apical membrane:T _K0.52,T _{HCO 3}=0.39 andT _Na=0.05, and its specific resistance was estimated to be 6000–7000 cm². From the basalT _K=0.90 and its specific resistance was estimated to be 400–1200 cm². From the basal potassium voltage responses the intracellular potassium concentration was estimated at 110mm. The shunt resistance consisted of two pathways: a paracellular one, due to the junctional complexes and another, around the edge of the tissue, due to the imperfect nature of the mechanical seal. In well-sealed tissues, the specific resistance of the shunt was about ten times the apical plus basal membrane specific resistances. This epithelium, therefore, should be considered tight. The shunt pathway did not distinguish between anions (HCO₃ ^–, Cl^–, methylsulfate, isethionate) but did distinguish between Na⁺ and K⁺.