Evidence of downstream migration of Sakhalin taimen, <Emphasis Type="Italic">Hucho perryi</Emphasis>, as revealed by Sr : Ca ratios of otolith

The migratory history of Sakhalin taimen, Hucho perryi, was examined in terms of strontium (Sr) and calcium (Ca) uptake in the otolith by using wavelength dispersive X-ray spectrometry on an electron microprobe. Otolioth Sr:Ca ratios of freshwater-reared samples remained consistently at low levels throughout the otolith. The Sr:Ca ratios of samples from Lake Aynskoye of Sakhalin Island showed a low value from the core up to a point of 700–2140µm. Thereafter, the ratios increased sharply and remained at higher levels up to the outermost regions. The difference in Sr:Ca ratio might be the result of the presence of individuals that underwent seawater and freshwater life history phases, probably reflecting the ambient salinity or the seawater–freshwater gradient in Sr concentration. Otolith Sr:Ca ratio analysis revealed downstream migration history in H. perryi.     

Xylem-specific expression of a GRP1.8 promoter::4CL gene construct in transgenic tobacco

Lignin is a complex aromatic polymer of vascular plants that provides mechanical strength to the stem and protects cellulose fibres from chemical and biological degradation. 4-Coumarate:CoA ligases (EC 6.2.1.12) are key enzymes for the biosynthetic pathway of monolignols which is an important complex aromatic polymer for lignin biosynthesis and tree growth. Recently, 4-coumarate:CoA ligase has been used as exogenous gene in transgenic plants to genetically modify the lignin biosynthesis pathway. Since most lignin is produced in the vascular cells, a tissue-specific-expressed promoter in the vascular cell would be important and useful to change and modify the content of lignin. Here we report the existence of a promoter of GRP1.8 (the glycine-rich protein 1.8) in Sopho japonica L. (GenBank accession number AF250149) and studies on its function in transgenic tobacco. The promoter activity was analyzed in transgenic tobacco plants by histochemical staining of GUS gene expression driven by a 613-bp sjGRP1.8p promoter sequence. In sjGRP1.8p-GUS transgenic plants, intense GUS staining was detected in the xylem of the stem. To further investigate the regulation of the tissue-specific expression of the 4CL1 gene, we analyzed the activity of the 4CL1 gene which is sense orientated with the sjGRP1.8p promoter in transgenic tobacco. The Pto4CL1 gene was expressed in the stem of transgenic tobacco. The activity of the 4CL1 enzyme was increased 1–2-fold in the stem but not increased in the leaves of transgenic tobacco. In comparison with the control plants, the content of lignin was increased 25% in the stem but there was no increase in the leaves of transgenic tobacco.     

Mode of uptake of sterol by Arthrobacter simplex

The mechanism of uptake of water-insoluble -sitosterol by a newly isolated strain of Arthrobacter simplex SS-7 was studied. The production of an extracellular sterol-pseudosolubilizing protein during growth of A. simplex on -sitosterol was demonstrated by isolating the factor from the cell-free supernatant and its subsequent purification by Sephadex G-150 column chromatography. The M _r of the purified sterol-pseudosolubilizing protein determined by SDS–PAGE was 19kDa. The rate of sterol pseudosolubilization (5.2×10^–3g l^–1h^–1) could not adequately account for the rate of sterol uptake (72×10^–3g l^–1h^–1) and the specific growth rate (56×10^–3 h^–1). However in the unfavourable growth condition, when the cells were treated with sodium azide at the level of 30–60% of MIC, the sterol pseudosolubilization accounted for nearly 74% of the total growth containing 96% free cells. Cellular adherence to substrate particles was found to play an active role in the normal growth of the strain on -sitosterol. Unlike sodium acetate-grown cells, whose surface activity was negligible (60mNm^–1), the sterol-grown cells had strong surface activity (40mNm^–1). The high lipid content and long chain fatty acids in the cell-wall of -sitosterol-grown cells probably contribute to the high sterol adherence activity of the cells.     

Proliferation and germination of somatic embryos from embryogenic suspension cultures in <Emphasis Type="Italic">Phœnix dactylifera</Emphasis>

The present study demonstrates a procedure for the rapid development of a high number of somatic embryos from embryogenic suspension culture. This method might be efficient for mass propagation of Phnix dactylifera L. Embryogenic callus placed in liquid medium with 10^–5M ABA yielded an average 72 embryos per 100ml of culture medium within 2months, while those placed on solid medium yielded an average of 33, 20 and 16 embryos per 100ml of culture medium respectively for 10^–7, 10^–6 and 10^–5 M ABA after 4months. The combination of 2,4-DIchlorophenoxyacetic acid (2,4-D) (4.5×10^–7M), glutamine (6.7×10^–4M), and ABA (10^–5M) (L8 liquid medium) showed a beneficial effect on somatic embryos production compared to 2,4-D and glutamine alone, while this combination significantly (p<0.05) increased the accumulation of storage proteins (144 and 138mgg^–1 DW respectively for Jihel and Bousthami noir cultivars) in somatic embryos. The somatic embryos which underwent maturation on medium containing only 4.5×10^–7M 2,4-D and 10^–5M ABA (L6 liquid medium) accumulated more sugars (292 and 265mgg^–1 DW respectively for Jihel and Bousthami noir) than those matured on any other liquid medium. Histological studies revealed that somatic embryos (developed in L6 and L8 liquid media) accumulated less reserve compounds (proteins and sugars) than zygotic embryos. The addition of activated charcoal (0.25 and 0.5gl^–1) and phytagel^® (2.5gl^–1) to the germination medium may be useful for enhancing the germination of Phnix dactyliferasomatic embryos.     

A new method for the determination of microbial activity and critical logP in the presence of organic solvents

A new method to determine microbial activity and critical logP of an organism in the presence of organic solvents has been developed which involves direct contact with a solvent, and a measurement of the developing colony size. This technique has been used to estimate the critical logP of Alcaligenes xylosoxidans Y234, and, although the critical logP for this organism is 3.5, solvents with logP values of up to 4.5 can still reduce microbial activity by up to 55% of the uninhibited amount.     

The relation between the levels of extractable and diffusible IAA in almond fruits and their “June drop”

The relationship between the June drop of almond fruits(cv. Truoito) and the levels of extractable and diffusible IAA of the fruit wasstudied. June drop started almost simultaneously with thedecreasein the concentration of extractable free and ester IAA from seeds and theamountof diffusible free IAA from persisting fruits. The drop lasted for a period ofabout 17 days, during which time the auxin decreased constantly. In a secondexperiment, the relationship between fruit size, fruit drop and level of auxinwas examined. The fruits were classified according to size into threecategories, large, intermediate and small. Throughout the experiment thepercentage of small fruits that abscised (70%) was five times higher than thatof the other categories of fruits. The small persisting fruits had lower levelsof extractable free and diffusible free IAA than fruits of intermediate andlarge size. When the process of abscission advanced and the diffusion of theauxin had been interrupted, an increase in the concentration of extractablefreeand peptidic IAA in the seeds and pericarps of the abscising fruits wasobservedcompared with the persisting fruits.     

Characterization of two beta-tubulin genes from Geotrichum candidum.

Summary The -tubulin genes G1 and G2 from the phytopathogenic hemiascomycete Geotrichum candidum were found to be highly diverged in amino acid sequence from those of other filamentous fungi. G1 and G2 were also divergent from each other, with the coding regions sharing only 66% nucleotide sequence homology and 64% amino acid identity. However, the proteins shared 82% similarity and only 25 of the 161 non-identical amino acid substitutions were non-conservative. The organization of G1 is similar to other fungal -tubulin genes, but G2 has several unusual features; it has 2 amino acid additions in the N-terminal 40 residues and must employ an uncommon 5 splice junction sequence in preference to an overlapping perfect consensus. The amino acid change found to confer benomyl resistance in Neurospora crassa was also present in G2. G1 has four introns which are located similarly to those of -tubulin genes in other fungi. G2, however, has a single intron in a unique location. Translational fusions employing the 5 non-coding regions of the two Geotrichum -tubulin genes were made with the hygromycin phosphotransferase gene and shown to function in Schizosaccharomyces pombe and Trichoderma hamatum. However, G. candidum could not be transformed with these or other tested plasmids commonly used for fungal transformation.     

The effect of paclobutrazol on in vitro rooting,transplant establishment and growth of fruit plants

The effect of paclobutrazol on in vitro rooting and growth of sour cherry (Prunus cerasus) rootstock CAB 11E clone, of S 749 × S 1490 (Prunus persica × Prunus kansuensis) hybrid rootstock, and of pear (Pyrus communis), cv. Abbé Fetel is reported.PP333 increased rooting of S 749 × S 1490 and of Abbé Fetel, particularly at a concentration of 0.5 mg/l (a.i.); moreover, it induced a rooting percentage as high as auxin in the former and hastened rooting of the latter. By contrast, paclobutrazol did not affect root production of 11 E.PP333-treated plants had shorter and thicker roots than controls but similar survival rates during acclimatization. Otherwise they grew less than controls during the first part of the acclimatization phase.Abbreviations used in text and tables BA = 6-benzyladenine - IBA = indole-3-butyric acid - PP333 = paclobutrazol = (2RS,3RS)-1-(-4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pentan-3-ol Part of the results referring to S 749 × S 1490 (P. persica × P. kansuensis) rootstock were presented at the meeting on Controllo della fruttificazione delle piante da frutto, Bologna, Italy, June 1986, and were published in the Riv. Ortoflorofrutt. It. 70 (6)(1986). This research was funded in part by the Italian Ministry of Education (M.P.I. 60%).     

Seasonal Changes in Reproductive Activity in the Potter's angelfish (Centropyge potteri) in Kaneohe Bay, Hawaii

Potter's angelfish, Centropyge potteri, is a protogynous hermaphrodite, with the alpha female of a harem becoming male under the proper social conditions. Gonads and plasma samples were collected from females every 6–9 days for 1 year, and then for every 4–6 weeks for another year. The gonadosomatic index (GSI) of females remained below 1% from July until December. Starting from the first week of December, large spikes occurred in the GSI, fluctuating from 1.4% to 4.1% and falling below 1% in June. Plasma concentrations of estradiol-17 were relatively low (1–2ngml^–1) between July and November. Beginning in the third week of November, large spikes of plasma estradiol-17 were observed, fluctuating from 0.5 to 5ngml^–1. This pattern continued until the third week of May, and then estradiol-17 levels remained low for the rest of the year. Estradiol-17 levels showed a highly significant correlation with GSI. Estradiol-17 levels during late vitellogenesis and final maturation were significantly greater than those of the other stages. These results suggest that the spawning season of the Potter's angelfish is from December to June. One of the causes of the large fluctuations in GSI and plasma estradiol-17 within the spawning season appears to be due to the fact that Potter's angelfish is an asynchronous daily spawner.     

Effect of hyperprolinemia on acetylcholinesterase and butyrylcholinesterase activities in rat

Summary. We observed here that acute proline (Pro) administration provoked a decrease (32%) of acetylcholinesterase (AChE) activity in cerebral cortex and an increase (22%) of butyrylcholinesterase (BuChE) activity in the serum of 29-day-old rats. In contrast, chronic administration of Pro did not alter AChE or BuChE activities. Furthermore, pretreatment of rats with vitamins E and C combined or alone, N-nitro-L-arginine methyl ester or melatonin prevented the reduction of AChE activity caused by acute Pro administration, suggesting the participation of oxidative stress in such effects.     

Enhancement of β-glucosidase stability and cellobiose-usage using surface-engineered recombinant Saccharomyces cerevisiae in ethanol production

To enhance the use of cellobiose by a recombinant Sachharomyces cerevisiae, the expressed -glucosidase that hydrolyzes cellobiose was stabilized using a surface-display system. The C-terminal half of -agglutinin was used as surface-display motif for the expression of -glucosidase in the cell wall. The surface-displayed -glucosidase had a half-life time (t _1/2) of 100 h in acidic culture broth conditions, while secreted -glucosidase had a t _1/2 of 60 h. With such stabilization of -glucosidase, the surface-engineered S. cerevisiae utilized 7.5 g cellobiose l^–1 over 60 h, while S. cerevisiae secreting -glucosidase into culture broth used 5.8 g cellobiose l^–1 over the same period.     

Enhanced growth,sporulation and toxin production by Bacillus thuringiensis subsp. kurstaki in oil seed meal extract media containing cystine

A mineral salts medium supplemented with peptone and 40mg% cystine supported enhanced sporulation (10¹¹spores/ ml) and high yields of insecticidal crystal protein (17.2mg/ml) in Bacillus thuringiensis subsp. kurstaki (3a3b) in 2.0l baffled aerated cylinders. These high yields could also be achieved with defatted soybean and groundnut seed meal extracts when supplemented with cystine.     

Copy Number Related Transgene Expression and Mosaic Somatic Expression in Hemizygous and Homozygous Transgenic Tilapia (Oreochromis Niloticus)

Three lines of transgenic tilapia (Oreochromisniloticus) fish were generated with a constructcontaining a lacZ reporter gene spliced to a 4.7kb 5 regulatory region of a carp beta actin gene. All these three lines contain different copy numbers oftransgenes and the levels of lacZ expressionwere found to be related to transgene copy number.Mosaic patterns of somatic lacZ expression wereobserved in these three lines which differed between linesbut were consistent within a line. We also observedthat expression of the reporter gene in homozygoustransgenic fish was approximately two-fold greater thanin the hemizygous transgenics. Analysis of expressionof the reporter gene on a tissue-to-tissue basisdemonstrated that lacZ expression of thereporter gene in stably transformed fish occured withvariable intensity in different organs and tissues andwas also sometimes variable in different cells of thesame tissue in G1and G2 generations of the transgenic lines.     

Characterization of Aeromonas salmonicida variants with altered cell surfaces and their use in studying surface protein assembly

Aeromonas salmonicida variants were characterized for alterations in their cell surface structure and used to examine reconstitution of the surface protein layer (A-layer). Variants lacking outer membrane O-polysaccharide were devoid of A-layer and excreted stainable floret-like material of the surface protein (A-protein). One variant, showing partial loss of O-polysaccharide, was associated with a disrupted A-layer and excretion of some A-protein. Variants lacking A-protein but possessing O-polysaccharide rapidly absorbed and concentrated sufficient excreted A-protein at the cell surface to coat the cells with a single confluent layer. Although differences in electrophoretic mobilities of A-proteins and O-polysaccharides from typical and atypical strains were evident, the different A-proteins and A-protein-deficient variants were interchangeable for reconstitution of a surface protein layer. No association of A-protein with cell surfaces of unrelated gram-negative bacteria was observed.Abbreviations A-layer additional surface protein layer - A-protein surface protein - Ast Aeromonas salmonicida typical - Asa Aeromonas salmonicida atypical - A^- phenotypically A-protein-negative variant - O^- phenotypically O-polysaccharide-negative variant - O^wk phenotypically O-polysaccharide weak variant - BHI brain heart infusion - SDS-PAGE sodium dodecylsulfate-polyacrylamide gel electrophoresis - TEM transmission electron microscopy     

Molecular cloning and sequencing analysis of a β-tubulin gene from Lupinus albus

Genomic -Dash library constructed from Lupinus albus nuclear DNA was screened using a fragment of the -tubulin cDNA ( 8–31) clone of Chlamydomonas reinhardtii as probe. One of the positive recombinant phages was isolated, subcloned and analysed by sequencing. We present here nucleotide and derived amino acid sequences of the -tubulin gene, designated as L1 and identified by similarity with other -tubulins. The L1-encoded protein reveals a very high degree of similarity with other plant tubulins and contains consensus sequences for binding guanine base, phosphate and Mg²⁺. Northern analysis of total RNA isolated from roots, leaves, flowers and pools revealed that Lupinus albus -tubulin genes are constitutively expressed in all studied plant tissues.     

Volume-sensitive taurine transport in fish erythrocytes

Summary Taurine plays an important role in cell volume regulation in both vertebrates and invertebrates. Erythrocytes from two euryhaline fish species, the eel (Anguilla japonica) and the starry flounder (Platichthys stellatus) were found to contain high intracellular concentrations of this amino acid ( 30 mmol per liter of cell water). Kinetic studies established that the cells possessed a saturable high-affinity Na⁺-dependent -amino-acid transport system which also required Cl^– for activity (apparentK _m (taurine) 75 and 80 m;V _max 0.85 and 0.29 mol/g Hb per hr for eel (20°C) and flounder cells (10°C), respectively. This -system operated with an apparent Na⁺/Cl^–/taurine coupling ratio of 211. A reduction in extracellular osmolarity, leading to an increase in cell volume, reversibly decreased the activity of the transporter. In contrast, low medium osmolarity stimulated the activity of a Na⁺-independent nonsaturable transport route selective for taurine, -amino-n-butyric acid and small neutral amino acids, producing a net efflux of taurine from the cells. Neither component of taurine transport was detected in human erythrocytes. It is suggested that these functionally distinct transport routes participate in the osmotic regulation of intracellular taurine levels and hence contribute to the homeostatic regulation of cell volume. Volume-induced increases in Na⁺-independent taurine transport activity were suppressed by noradrenaline and 8-bromoadenosine-3, 5-cyclic monophosphate, but unaffected by the anticalmodulin drug, pimozide.     

Linear differentiation of cereal chromosomes

Summary The BSG test was used in a comparative study of the linear chromosome differentiation and the idiograms of T. Macha ssp. tubalicum v. letschchumicum Dek. et Men., T. georgicum Dek., T. timopheevi. Zhuk., T. carthlicum Nevski, T. dicoccum Schrank, v. rufum, T. durum Desf. v. Arnautka were compiled.The karyotype of each polyploid wheat species consists of two groups of chromosomes. The first is formed by ten pairs of constant chromosomes occurring almost in all species and the second by all the rest of the variable chromosomes that are either fully specific for the species in question or occur only in a few species. T. timopheevi largely differs from other species of polyploid wheats in the high level and specific localization of structural heterochromatin on chromosomes. The rols of introgression in wheat evolution and the necessity of establishing a General Cytological Nomenclature of Cereal Chromosomes are discussed.     

β-1-3- and β-1-4-glucan synthesis by membrane fractions from the fungus Saprolegnia

The -glucan synthetase activity of the fungus Saprolegnia monoica was assayed by supplying UDP-glucose to membrane fractions of mycelial homogenate. The analysis of glucan products by hydrolysis with various -glucanases and by chromatography show that both -1-3- and -1-4-linkages are formed at high substrate concentrations. In the absence of MgCl₂, -1-3-linked glucans are mainly produced. By increasing MgCl₂ concentrations the total synthesis activity and -1-3-linkages production are reduced. At low substrate concentrations in the presence of MgCl₂, -1-4-linked glucans are the only polysaccharide synthesized. Electron microscopy of radioactive products, synthesized by original membrane fractions or by membrane fractions isolated from continuous sucrose density gradients, shows microfibrils when the assays are conducted at high substrate concentrations in the absence of MgCl₂.Abbreviations G.S. I glucan synthetase I - G.S. II glucan synthetase II - Dol. P dolichol phosphate     

The feeding ecology of a carnivorous plant (Pinguicula nevadense): prey analysis and capture constraints

Summary The taxonomic composition and size of arthropods captured by Pinguicula nevadense, an endemic carnivorous plant of the high-mountain zone of the Sierra Nevada (southern Spain), are analysed. The actual prey of P. nevadense and the available arthropods trapped by mimic-traps are compared, in order to identify the capture constraints of the plant. The results show that P. nevadense captures various arthropod taxa. Winged insects, especially Nematocera, make up the main component of the diet. The range of prey sizes in all P. nevadense populations studied is similar. The taxonomic composition of arthropods trapped by the mimic-traps is similar to that of the actual prey of P. nevadense. However, the plant captures prey only below a specific size threshold. These size constraints appear to be the principal factor determining the actual prey of this carnivorous plant.     

Cloning and expression in Saccharomyces cerevisiae of a β-amylase gene from the oomycete Saprolegnia ferax

Genomic DNA and cDNA encoding the -amylase from the oomycete, Saprolegnia ferax, were cloned into Saccharomyces cerevisiae and analyzed. The Spl. ferax -amylase gene consisted of a 1350 bp open reading frame, encoding a protein of 450 amino acids with a calculated mass of 49353 Da, and was not interrupted by any intron. The deduced amino acid sequence of the -amylase gene had 42% similarity to the -amylase of Arabidopsis thaliana. The -amylase gene was expressed in Sacc. cerevisiae and its product was secreted into the culture medium.