ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • growth  (269)
  • Immunocytochemistry
  • Saccharomyces cerevisiae
  • Springer  (636)
  • 1995-1999  (636)
Collection
Keywords
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    European journal of nutrition 36 (1997), S. 299-302 
    ISSN: 1436-6215
    Keywords: Energy retention ; protein retention ; fat retention ; growth ; body composition ; broilers ; Energieansatz ; Proteinansatz ; Fettansatz ; Wachstum ; Körperzusammensetzung ; Broiler
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Mit steigender Aufnahme erhöht sich der Körperfettgehalt und der Körperproteingehalt nimmt ab. Es wird oft angenommen, daß jede Zunahme im Ansatz mit mehr Fett und weniger Protein verbunden ist. Experimentelle Ergebnisse widerlegen jedoch diese Annahme. In zwei Experimenten mit männlichen Broilerhühnern wurden die Tiere auf einem Niveau von 60 % und 100 % der empfohlenen Energieaufnahme gefüttert. Die Körperzusammensetzung bei 1500 g zeigte, wie erwartet, daß sich bei steigenden Aufnahmen der Körperfettgchalt vergrößert und der Körperproteingehalt abnimmt. Fettund Proteinansatz waren linear mit der totalen Energieretention (ER) korreliert. Das bedeutet, daß jede Zunahme im Ansatz den gleichen Protein- und Fettgehalt besitzt. Wenn der Fettansatz gleich Null ist wird nur Protein, etwa 50 % des maximalen Ansatzes, retiniert. Wenn ER=O ist, wird Protein angesetzt und Fett mobilisiert. Energie-und N-Bilanzuntersuchungen bestätigen die konstante Zusammensetzung jeder Vergrößerung des Ansatzes. Die Ergebnisse beider Experimente zeigen, daß die ER aus zwei Komponenten besteht: einem basalen konstanten täglichen Proteinansatz und einer variablen zusätzlichen ER, die hauptsächlich aus Fett besteht. Der basale Proteinansatz beträgt etwa 50 % des maximalen Ansatzes. Mit steigenden Energieaufnahmen wird der basale Proteinansatz mit einer zusätzlichen Menge von Protein und Fett im konstanten Verhältnis ergänzt.
    Notes: Summary With increasing intakes the body fat content increases and that of protein decreases. It is most often assumed that this is brought about because each increment in retention contains more fat and less protein. Experimental results, however, showed that this explanation is not true. In two experiments male broiler chickens were fed at levels between 60 and 100 % of recommended energy intake. Body composition at 1500 g showed, as expected, that with increasing intakes body fat content increased and protein content decreased. Both fat and protein retention per day were linearly related to total energy retention (ER). This means that each increment in retention has the same protein and fat content. At zero fat retention only protein was retained, about 50 % of maximal retention. At zero ER protein was retained and fat mobilized. Energy and N balance experiments confirmed the constant composition of each increment in retention. The results of both experiments show that total ER consisted of two components: a basic constant daily protein retention and a variable additional ER, mainly consisting of fat. The basic protein retention is about half of maximal retention. With increasing energy intakes the basic protein retention is combined with an additional amount of protein and fat in a constant ratio.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European journal of nutrition 36 (1997), S. 332-335 
    ISSN: 1436-6215
    Keywords: Nutrient intake ; protein metabolism ; protein synthesis ; growth ; energy expenditures ; Nährstoffaufnahme ; Proteinstoffwechsel ; Proteinsynthese ; Wachstum ; Energieaufwand
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Eine Zunahme von fettfreiem Gewebe tritt auf, wenn die Proteinsynthese größer ist als der Proteinabbau. Obwohl während des Wachstums von der Geburt bis zur Reife die absoluten Proteinsynthese- und -abbauraten ansteigen, nehmen dagegen die fraktionellen Raten ab. Bcide Prozesse reagieren auf die Nährstoffaufnahme. Es gibt aber deutliche Unterschiede zwischen den verschiedenen Geweben. Protein, Kohlenhydrate und Fett können den Proteinansatz bei unreifen Tieren und Kindern stimulieren. Die zugrundeliegenden Mechanismen und die Energieaufwendungen scheinen jedoch unterschiedlich zu sein.
    Notes: Summary Lean tissue growth occurs when the rate of protein synthesis exceeds the rate of protein breakdown. Althoughabsolute rates of protein synthesis and breakdown rise during growth from birth to maturityfractional rates fall. Both these processes are sensitive to nutrient intake but responses to feeding vary greatly amongst different tissues. Protein, carbohydrate and fat can all stimulate body protein accretion in immature animals and in children but the mechanisms by which they do so, and the energy expenditures involved, seem to be different.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Empirical economics 24 (1999), S. 23-44 
    ISSN: 1435-8921
    Keywords: Key words: Cointegration ; convergence ; growth ; Kalman filter ; JEL classifications: C22 ; O47 ; O57
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract. Augmented Dickey Fuller (ADF) and Kalman filter convergence tests are applied to annual GDPs per head to 16 industrialised countries from 1890 to 1989. Results favour convergence towards the US with a structural break following the Second World War. Estimates suggest that steady-states were higher after the war and that speeds of convergence are different across countries. The Kalman filter method dismissed the no convergence hypothesis more often than its ADF counterpart. This could explain the apparent contradiction in earlier empirical work on similar data sets (cross-section methods tended to favour convergence while time series methods were unable to dismiss the no convergence hypothesis.)
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 80 (1996), S. 141-144 
    ISSN: 1570-7458
    Keywords: Polygonia c-album ; Nymphalidae ; host-plant selection ; growth ; size
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1570-7458
    Keywords: amylase inhibitor ; red kidney bean ; hard red winter wheat ; growth ; insects ; beetles ; plant resistance ; stored products ; protease inhibitor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Insect α-amylase inhibiting and/or growth inhibiting activities of proteinaceous inhibitors from red kidney bean (Phaseolus vulgaris) and hard red winter wheat (Triticum aestivum) were examined. The bean inhibitor was most effectivein vitro against α-amylases from the red flour beetle (Tribolium castaneum) and the confused flour beetle (T. confusum), followed by those from the rice weevil (Sitophilus oryzae) and yellow mealworm (Tenebrio molitor). The insect enzymes were from two- to 50-fold more susceptible than human salivary α-amylase. When the inhibitors were added at a 1% level to a wheat flour plus germ diet, the growth of red flour beetle larvae was slowed relative to that of the control group of larvae, with the bean inhibitor being more effective than the wheat inhibitor. Development of both the red flour beetle and flat grain beetle (Cryptolestes pusillus) was delayed by 1% bean inhibitor, but development of the sawtoothed grain beetle (Oryzaephilus surinamensis) and lesser grain borer (Rhyzopertha dominica) was not affected by either the bean or wheat inhibitor at the 1% level. Rice weevil adults fed a diet containing 1% bean or wheat inhibitor exhibited more mortality than weevils fed the control diet. When the wheat amylase inhibitor was combined with a cysteine protease inhibitor, E-64, and fed to red flour beetle larvae, a reduction in the growth rate and an increase in the time required for adult eclosion occurred relative to larvae fed either of the inhibitors separately. The bean inhibitor was just as effective alone as when it was combined with the protease inhibitor. These results demonstrate that plant inhibitors of insect digestive enzymes act as growth inhibitors of insects and possibly as plant defense proteins, and open the way to the use of the genes of these inhibitors for genetically improving the resistance of cereals to storage pests.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 79 (1996), S. 335-344 
    ISSN: 1570-7458
    Keywords: alkaloid ; developmental time ; early instars ; growth ; Manduca sexta ; molting duration ; phenolics ; plant-herbivore interactions ; thermal regime
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To understand the mechanisms underlying plant-insect herbivore interactions, it is necessary to examine the simultaneous effects of temperature, food quality and larval age. We examined the simultaneous effects of three allelochemicals (tomatine, rutin and chlorogenic acid) on the performance of first and second instar Manduca sexta larvae under two representative thermal regimes 21 : 10°C and 26 : 15°C for spring and summer, respectively. Thermal regime and allelochemicals interacted to influence the time from egg hatch to ecdysis to the third instar. On average, it took about half as much time to reach the third instar at 26 : 15°C as it did at 21 : 10°C. Separately, tomatine and rutin had a negative effect on developmental time from egg hatch to the third instar, but their simutaneous effects were not additive. Chlorogenic acid significantly reduced the negative effect of tomatine. The magnitude of the allelochemical effect was larger at the cooler thermal regime compared to the warmer regime. For instance, chlorogenic acid by itself had no effect at the 26 : 15°C regime, but at the 21 : 10°C regime it significantly shortened total developmental time. The effect of chlorogenic acid on stadium duration was distinctly different for the two instars. Chlorogenic acid shortened stadium duration of first instar larvae. However, depending on thermal regime and the presence of tomatine, chlorogenic acid had a negative, positive or neutral effect on stadium duration of second instar larvae. Molting duration of second instar larvae was shortened by a half day at the warmer thermal regime but was not affected by the allelochemicals. Final larval weight was influenced by rutin and chlorogenic acid. Caterpillars fed diets containing 20 μmoles of rutin were on average 10% lighter than those fed plain diet, whereas those fed diets containing 20 μmoles of chlorogenic adic were on average 7% heavier. However, the effect of chlorogenic acid depended on thermal regime. Overall, our results indicated that: 1) temperature and food quality can interact to influence insect performance and 2) these effects are influenced by larval age.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 80 (1996), S. 443-451 
    ISSN: 1570-7458
    Keywords: beta-carboline alkaloid ; Trichoplusia ni ; harmane ; harmaline ; amitriptyline ; imipramine ; monoamine oxidase inhibitor ; tricyclics ; growth ; feeding behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this study we investigated the effects of two naturally occurring beta-carboline alkaloids and two synthetic tricyclic antidepressants on the growth and food consumption of fifth instar larvae of the cabbage looper, Trichoplusia ni Hübner (Lepidoptera: Noctuidae). In artificial diets at high concentrations (3,000 ppm), harmane, amitriptyline, and imipramine reduce growth and feeding; harmane reduced feeding consistently at a lower concentration (200 ppm). In animals other than insects, beta-carboline alkaloids inhibit monoamine oxidase (MAO) activity and thus affect rates of disposition of serotonin and other monoamine neurotransmitters. Because brain serotonin levels are associated with variation in rates of carbohydrate and protein intake in insects, the effects of beta-carboline alkaloid ingestion on dietary self-selection behavior were examined. Choosing between diets lacking carbohydrate but containing protein and diets lacking protein but containing carbohydrate, larvae consumed a greater proportion of diet containing protein but lacking carbohydrate in the presence of harmane than in its absence. These results are consistent with beta-carboline alkaloid-mediated persistence of serotonin in the brain due to MAO inhibition. Alternatively, these results could reflect alkaloid-mediated peripheral inhibition of sucrose taste receptors influencing ingestive behaviors. That beta-carboline alkaloid ingestion is associated with changes in feeding behavior is consistent with a possible defensive role for these compounds in plant foliage.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1570-7458
    Keywords: insect endocrinology ; ecdysone ; juvenile hormone ; reproduction ; growth ; inhibin ; oostatin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The first insect folliculostatic peptide was isolated from vitellogenic ovaries of the mosquitoAedes aegypti. This decapeptide directly inhibits trypsin biosynthesis in the gut, and indirectly ovarian development. The factor was named Trypsin Modulating Oostatic Factor or TMOF by its discoverers. From the fleshfly Neobellieria bullata 2 folliculostatins have been isolated, the hexapeptide Neb-TMOF and the 19-mer Neb-colloostatin. The available data suggest that at least 2 of the 3 folliculostatins originate from matrix (like) proteins present in the ovary, a hitherto unknown source of hormones. Furthermore, one of the folliculostatins (Neb-TMOF) is a potent inhibitor of ecdysone biosynthesis by larval ring glands of fleshflies. The discovery of the dipteran folliculostatins, which do not show any resemblance to inhibins of vertebrates, may significantly contribute to a better understanding of the hormonal control of growth in insects and perhaps, in other animals as well. None of the 3 folliculostatins is blocked at its N- or C-terminus. This, in combination with the pleiotropy of their effects and the narrow species specificity make such peptides prime candidates for, testing their potential in insect pest control by means of molecular biological methods.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1572-8773
    Keywords: iron ; siderophores ; transport ; Saccharomyces cerevisiae ; fungi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Transport proteins of microorganisms may either belong to the ATP-binding cassette (ABC) superfamily or to the major facilitator (MFS)-superfamily. MFS transporters are single-polypeptide membrane transporters that transport small molecules via uniport, symport or antiport mechanisms in response to a chemiosmotic gradient. Although Saccharomyces cerevisiae is a non-siderophore producer, various bacterial and fungal siderophores can be utilized as an iron source. From yeast genome sequencing data six genes of the unknown major facilitator (UMF) family were known of which YEL065w Sce was recently identified as a transporter for the bacterial siderophore ferrioxamine B (Sit1p). The present investigation shows that another UMF gene, YHL047c Sce, encodes a transporter for the fungal siderophore triacetylfusarinine C. The gene YHL047c Sce (designated TAF1) was disrupted using the kanMX disruption module in a fet3 background (strain DEY 1394 Δfet3), possessing a defect in the high affinity ferrous iron transport. Growth promotion assays and transport experiments with 55Fe-labelled triacetylfusarinine C showed a complete loss of iron utilization and uptake in the disrupted strain, indicating that TAF1 is the gene for the fungal triacetylfusarinine transport in Saccharomyces cerevisiae and possibly in other siderophore producing fungi.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1572-8773
    Keywords: EPR ; Saccharomyces cerevisiae ; uptake ; vanadate ; vanadyl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Vanadium uptake by whole cells and isolated cell walls of the yeast Saccharomyces cerevisiae was studied. When orthovanadate was added to wild-type S. cerevisiae cells growing in rich medium, growth was inhibited as a function of the VO4 3- concentration and the growth was completely arrested at a concentration of 20 mM of VO4 3- in YEPD. Electron paramagnetic resonance (EPR) spectroscopy was used to obtain structural and dynamic information about the cell-associated paramagnetic vanadyl ion. The presence of EPR signals indicated that vanadate was reduced by whole cells to the vanadyl ion. On the contrary, no EPR signals were detected after interaction of vanadate with isolated cell walls. A ‘mobile’ and an ‘immobile’ species associated in cells with small chelates and with macromolecular sites, respectively, were identified. The value of rotational correlation time τ r indicated the relative motional freedom at the macromolecular site. A strongly ‘immobilized’ vanadyl species bound to polar sites mainly through coulombic attractions was detected after interaction of VO2+ ions with isolated cell walls.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 52 (1996), S. 1130-1135 
    ISSN: 1420-9071
    Keywords: Saccharomyces cerevisiae ; mitochondria ; mRNA-specific translational activation ; synthetic genes ; gene regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Mitochondrial gene expression in yeast,Saccharomyces cerevisiae, depends on translational activation of individual mRNAs by distinct proteins encoded in the nucleus. These nuclearly coded mRNA-specific translational activators are bound to the inner membrane and function to mediate the interaction between mRNAs and mitochondrial ribosomes. This complex system, found to date only in organelles, appears to be an adaptation for targeting the synthesis of mitochondrially coded integral membrane proteins to the membrane. In addition, mRNA-specific translational activation is a rate-limiting step used to modulate expression of at least one mitochondrial gene in response to environmental conditions. Direct study of mitochondrial gene regulation and the targeting of mitochondrially coded proteins in vivo will now be possible using synthetic genes inserted into mtDNA that encode soluble reporter/passenger proteins.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 52 (1996), S. 1033-1041 
    ISSN: 1420-9071
    Keywords: Ubiquitin ; yeast ; Saccharomyces cerevisiae ; Dictyostelium discoideum ; cytoskeleton ; mutants ; endocytosis ; actin ; myosin ; calmodulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Endocytosis is a general term that is used to describe the internalization of external and plasma membrane molecules into the cell interior. In fact, several different mechanisms exist for the internalization step of this process. In this review we emphasize the work on the actin-dependent pathways, in particular in the yeastSaccharomyces cerevisiae, because several components of the molecular machinery are identified. In this yeast, the analysis of endocytosis in various mutants reveals a requirement for actin, calmodulin, a type I myosin, as well as a number of other proteins that affect actin dynamics. Some of these proteins have homology to proteins in animal cells that are believed to be involved in endocytosis. In addition, the demonstration that ubiquitination of some cell surface molecules is required for their efficient internalization is described. We compare the actin, myosin and ubiquitin requirements for endocytosis with recent results found studying these processes usingDictyostelium discoideum and animal cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 52 (1996), S. 1111-1116 
    ISSN: 1420-9071
    Keywords: Mitochondria ; mitochondrial inheritance ; cytoskeleton ; Saccharomyces cerevisiae ; Schizosaccharomyces pombe ; membrane proteins ; organelle movement ; mitochondrial morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Mechanisms mediating the inheritance of mitochondria are poorly understood, but recent studies with the yeastsSaccharomyces cerevisiae andSchizosaccharomyces pombe have begun to identify components that facilitate this essential process. These components have been identified through the analysis of conditional yeast mutants that display aberrant mitochondrial distribution at restrictive conditions. The analysis of these mutants has uncovered several novel proteins that are localized either to cytoskeletal structures or to the mitochondria themselves. Many mitochondrial inheritance mutants also show altered mitochondrial morphology and defects in maintenance of the mitochondrial genome. Although some inheritance components and mechanisms appear to function specifically in certain types of cells, other conserved proteins are likely to mediate mitochondrial behavior in all eukaryotic cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    ISSN: 1420-9071
    Keywords: Saccharomyces cerevisiae ; mitochondrial ribosomes ; peptidyl transferase ; Varl ribosomal protein ; gene relocation ; posttranscriptional rRNA modification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Mitochondria posses their own ribosomes responsible for the synthesis of a small number of proteins encoded by the mitochondrial genome. In yeast,Saccharomyces cerevisiae, the two ribosomal RNAs and a single ribosomal protein, Varl, are products of mitochondrial genes, and the remaining approximately 80 ribosomal proteins are encoded in the nucleus. The mitochondrial translation system is dispensable in yeast, providing an excellent experimental model for the molecular genetic analysis of the fundamental properties of ribosomes in general as well as adaptations required for the specialized role of ribosomes in mitochondria. Recent studies of the peptidyl transferase center, one of the most highly conserved functional centers of the ribosome, and the Varl protein, an unusual yet essential protein in the small ribosomal subunit, have provided new insight into conserved and divergent features of the mitochondrial ribosome.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    BioMetals 12 (1999), S. 289-294 
    ISSN: 1572-8773
    Keywords: accumulation ; gold ; proton efflux ; Saccharomyces cerevisiae ; toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract This paper examines the effects of ionic gold on Saccharomyces cerevisiae, as determined by long-term (growth in gold-containing media) and short-term interactions (H+ efflux activity). An increasing gold concentration inhibited growth and at 〈0.2 mM Au, growth was not observed. Transmission electron microscopy revealed no differences in ultrastructure but fine electron dense particles were observed in unstained preparations from gold-containing medium. After glucose addition (to 10mM) to starved suspensions of S. cerevisiae, glucose-dependent reduction of external pH occurred as the cells extruded protons. In the presence of increasing gold concentrations, the lag time before proton extrusion did not change but the rate and duration decreased significantly with a marked influence on proton efflux rate being observed at ≤ 10 μM. Extension of preincubation time of yeast cells in gold-containing medium resulted in a decreasing proton efflux rate and colloidal phase formation in the cell suspensions, the time between gold addition and the beginning of colloidal phase formation depending on the gold concentration used. Both Ca and Mg enhanced the inhibitory effect of gold on the yeast cells with Ca showing a stronger inhibitory effect than Mg.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Springer
    European journal of nutrition 36 (1997), S. 205-213 
    ISSN: 1436-6215
    Keywords: Frying ; growth ; liver lipids ; lipaemia ; olive oil ; pregnancy ; rat ; Fritierung ; Wachstum ; Leberfett ; Olivenöl ; Schwangerschaft ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Um Informartionen über den Zusammenhang zwischen der Aufnahme von Fett, das zum Fritieren benutzt wurde, und dem Fetthaushalt während Perioden starken Körperaufbaus zu haben, wurde der Einfluß der Aufnahme von frischem Olivenöl (Gehalt polarer Verbindungen, 2 %; Ölsäure 78,9 mg/100 mg Öl, und Linolsäure 7 mg/100 mg Öl) und von Olivenöl, das 15 mal in Folge für das Fritieren von Kartoffeln benutzt worden war (Gehalt polarer Verbindungen 9 %; Ölsäure 75,8 mg/100mg Öl und Linolsäure 6,2 mg/100mg Öl) während der Gravidität, untersucht. Dazu wurden trächtige Wistar Ratten in zwei Gruppen geteilt, die beide eine isokalorische Diät bekamen, deren Fettanteil 15 % von frischem (unbenutztem) (P1) bzw. fritiertem (benutztem) (P2) Olivenöl stammte mit nicht trächtigen Ratten verglichen. Die Gravidität erhöhte (p〈0,01) die Futteraufnahme, das Körpergewicht, die Gewichtszunahmen und die Futterverwertung. Die Ölqualität beeinflußte dagegen diese Parameter nicht. Während der Gravidität stiegen die Serumwerte der Triglyceride (TG) (p〈0,01) und des Cholesterins (TC) (p〈0,05) an, während die der Phosphatide (PH) sanken (p〈0,01). Ein signifikanter Effekt der Ölqualität und eine Wechselwirkung zwischen Gravidität und Öl wurde für TG und PH festgestellt. Das Gewicht und der Fettgehalt der Leber der trächtigen Ratten stiegen signifikant an (p.〈0.05), Leber TC, TG und PH stiegen während der Gravidität (ungefähr um das 3-fache der Ausgangswerte), aber es traten keine signifikanten Unterschiede zwischen der Aufnahme von benutztem und nicht benutztem Öl (P2 vs P1) auf. Die Ergebnisse zeigen, daß die Aufnahme von leicht verdorbenem Olivenöl als alleinige Fettquelle der Nahrung keine besonderen Folgen für die Gravidität hat, was die Gewichtszunahme der Mütter und der Feten, die Lipämie und die Zusammensetzung des Leberfetts betrifft.
    Notes: Summary The effect of the consumption of unused olive oil (polar content, 2 %; oleic acid, 78.9 mg/100 mg oil, and linoleic acid 7 mg/100 mg oil) and olive oil used discontinuously for frying potatoes 15 times (polar content, 9 %; oleic acid, 75.8 mg/100 mg oil and linoleic acid 6.2 mg/100 mg oil) was studied in pregnant rats with the aim of better understanding the relationship between the consumption of fat used in frying and lipid metabolism during periods of intense anabolism. Trials were performed in pregnant Wistar rats, divided into 2 groups and fed isocaloric diets in which the fat content (15 % wt/wt) consisted of unused olive oil (P1) or oil previously used for frying (P2), and the results were compared with those of nonpregnant rats fed unused olive oil (NP1) and olive oil used for frying (NP2). Pregnancy increased (p〈0.01) food intake, body weight, weight gain, and food efficiency ratio (P2 vs NP2 and P1 vs NP1, respectively), but the treatment of oil included in the diets did not alter these parameters. Gestation significantly increased the serum triglyceride (TG) (p〈0.01) and total cholesterol (TC) (p〈0.05) concentrations and diminished that of phospholipids (PH) (p〈0.01). A significant effect of the type of oil consumed and a pregnancy x oil interaction on Tg and PH levels was observed. The weight of the liver and its fat content increased significantly (p〈0.05) as a result of pregnancy. Liver TC, TG, and PH increased (approximately 3 times the original values) during gestation, but no significant differences due to the intake of used or unused oil (P2 vs P1) were observed. The results indicate that the consumption of moderately altered olive oil, as the sole source of fat, does not alter the effect of pregnancy on the mothers' weight gain, lipaemia, and hepatic fat composition to any important degree.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 1436-6215
    Keywords: Body composition ; fat ; growth ; somatotropin ; pig ; Körperzusammensetzung ; Fett ; Wachstum ; Somatotropin -Schwein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung An 78 männlichen Kastraten und weiblichen Schweinen der Kreuzung Pietrain x (Deutsches Edelschwein x Deutsche Landrasse) wurden Untersuchungen zum Einfluß einer porcinen Somatotropin (pST)-Behandlung während des Wachstums auf die chemische Körperzusammensetzung der Tiere, das Adipozyten-Wachstum und das Fettsäure-Profil des Rückenspecks untersucht. Die intramuskulären Injektionen (1 oder 3 mg pST) wurden täglich ab durchschnittlich 65 kg Lebendgewicht bis zum Schlachten verabreicht. Nach der pST-Behandlung wurden bei den Kastraten in allen untersuchten Merkmalen signifikante Unterschiede festgestellt, während sich bei den weiblichen Tieren nur leichte Reaktionen zeigten. Das pST verursachte eine Zunahme des Wasserund Proteingehaltes bei gleichzeitiger Reduzierung des Lipidgehaltes besonders in den fettreichen Körperteilen der Tiere. Im Rückenspeck war der Gehalt an ungesättigten Fettsäuren erhöht und der Fettzelldurchmesser erniedrigt.
    Notes: Summary Seventy eight growing-finishing pigs (male castrates and females) of the cross-breed Pietrain x (Large White x German Landrace) were used to investigate the effects of pST treatment on the chemical composition of the body, the growth of adipocytes, and the fatty acid profile of the backfat. Intramuscular injections (1 or 3 mg pST) were administered daily from an average weight of 65 kg up to slaughter. After pST treatment significant changes in all studied characteristics were observed in barrows, whereas the females exhibited very small responses. The pST caused an increase of water and protein contents and a simultaneous decrease of lipid content especially in body parts rich in fat. Furthermore, the proportion of unsaturated fatty acids increased and the fat cell diameter decreased in the backfat.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Journal of productivity analysis 8 (1997), S. 293-310 
    ISSN: 1573-0441
    Keywords: growth ; USagriculture ; externalities ; spill-overs ; public R and D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract Growth in U.S. agriculture is linked to the non-farm economy through domestic terms of trade and factor market adjustments. With almost stable input growth, the relatively large contributions from growth in Total Factor Productivity (TFP) are passed on to intermediate and final consumers in the form of declining real prices for primary farm products. The resulting net growth in the real value of farm output (GDP) is relatively low (0.25% per annum). The decomposition of TFP suggests that public agricultural stock of knowledge and infrastructure are “robustly” associated with TFP growth, while spill-overs from private agricultural and economy wide research and development (R and D) are positive but, relatively small.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    ISSN: 1573-0832
    Keywords: ELISA ; Endodermis ; H. annosum ; Immunocytochemistry ; Root rot ; Vascular tissues
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Vascular disintegration mainly of medulla rays of spruce roots is of major significance in root rot disease of spruce caused byH. annosum. Using seedling roots as an experimental model, the possible routes and initial host reactions preceding invasion of vascular tissues was investigated. Transmission electron microscopy showed that penetration through the endodermis was an obvious route but not without host resistance. Using antibodies againstH. annosum hyphal materials, some labelling of vascular tissues remote from sites of fungal colonization suggest the release of fungal secretory products partly active in tissue disintegration. Similarly, intense labelling was also observed in severely colonized host tissues at late stages of infection. Strong labelling recorded at 3 d p.i. mainly on fungal hyphae and scant gold particles on invaded host tissues could imply that induction of host antifungal metabolites may have been a late event. A correlation was found between total antigenic material in root homogenates measured by ELISA, density of tissue labelling by immunocytochemistry and severity of disease symptoms. The importance of this in relation to diagnosis of biotic root rot diseases in the field is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Mycopathologia 142 (1998), S. 67-70 
    ISSN: 1573-0832
    Keywords: l-glutamine ; fructose-6-phosphate amidotransferase ; Candida albicans ; fungi ; Saccharomyces cerevisiae ; Schizosaccharomyces pombe ; systemic mycoses chemotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The 3' part of the glucosamine-6-phosphate synthase gene from Histoplasma capsulatum was PCR amplified using degenerate primers designed from the known glucosamine-6-phosphate synthase gene sequences, cloned and sequenced. The computer analysis of the 676 bp sequence revealed the presence of two introns. The identities of the deduced amino acid sequence to the corresponding Saccharomyces cerevisiae and Candida albicans fragment are 65 and 63.8%, respectively.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    ISSN: 1572-9699
    Keywords: growth inhibition ; fatty acid composition ; Saccharomyces cerevisiae ; Yarrowia lipolytica ; Teucrium polium L. extract
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Aqueous Teucrium polium extract slightly inhibits the growth of Saccharomyces cerevisiae (Ki=0.029 [g/l]-1) and Yarrovia lipolytica (Ki=0.061 [g/l]-1). However, this extract causes important changes in the unsaturation degree (Δ/mol) of the cellular lipids. It moreover favours the increase of the linolenic acid concentration and the decrease of the oleic one in both species.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    ISSN: 1572-977X
    Keywords: Avicennia alba ; growth ; internodal sequences ; mangrove age determination ; Rhizophora apiculata ; Sonneratia caseolaris ; Thailand
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The occurrence of periodic changes in the length of the internodes of the seedlings of SE Asian mangrove species (Rhizophora apiculata, Avicennia alba, and Sonneratia caseolaris) growing in the Pak Phanang estuary (Nakhon Si Thammarat, SE Thailand) was confirmed. The annual nature of these periodic changes was verified through comparisons with the observed average number of internodes produced by plants tagged for one year. The cycles in the sequence of internodal length of the seedlings had an average (± SE) period of 16.0 ± 0.78 internodes for Avicennia alba, 25.0 ± 1.2 internodes for Sonneratia caseolaris, and 8.29 ± 0.40 internodes for Rhizophora apiculata. These values are remarkably close to, and not significantly different (t‐test, P 〉 0.05) from the average (± SE) annual number of internodes of 17.6 ± 0.8 for Avicennia alba, 28.8 ± 2.1 for Sonneratia caseolaris, and 8.03 ± 0.36 for Rhizophora apiculata produced in a year by tagged plants. In addition, the average (± SE) growth of the tagged plants was 0.39 ± 0.018 cm day-1 for Avicennia alba, 0.24 ± 0.015 cm day-1 for Sonneratia caseolaris, and 0.091 ± 0.0036 cm day-1 for Rhizophora apiculata. These estimates were very close to those (0.45 ± 0.06 cm day-1 for Avicennia alba, 0.32 ± 0.01 cm day-1 for Sonneratia caseolaris, and 0.13 ± 0.005 cm day-1 for Rhizophora apiculata) derived as the product of the mean number of internodes produced per day, calculated from the inferred number of internodes produced per year, and the mean length of the internodes of the plants. These findings indicate that the use of regular, annual changes in the length of the internodes of mangrove seedlings can be used reliably to determine their age and to estimate their growth rate.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    ISSN: 1423-0127
    Keywords: Acquired immunodeficiency syndrome ; Human immunodeficiency virus ; Nef protein ; Myristylation ; Membrane permeabilisation ; Saccharomyces cerevisiae ; Yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The human immunodeficiency virus type 1 (HIV-1) Nef protein is essential for AIDS pathogenesis, but its function remains highly controversial. During stresses such as growth in the presence of copper or at elevated temperature, myristylated Nef is released from yeast cells and, after extended culture in stationary phase, it accumulates in the supernatant as a dense membranous material that can be centrifuged into a discrete layer above the cell pellet. This material is unique to Nef-producing cells and represents a convenient source of Nef that may have application in further biological studies. Within the yeast cell, electron microscopic examination shows that Nef localises in novel, membrane-bound bodies. These data support the evidence for a role of Nef in membrane perturbation and suggest that there may be a similar localisation for myristylated Nef in HIV-1 infected cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    ISSN: 1420-9071
    Keywords: Alternating high magnetic fields ; eddy current ; magnetic flux concentration ; Caenorhabditis elegans ; growth ; reproduction ; behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Here we describe a device for testing possible influences of high magnetic fields on biological processes, by which alternating-current magnetic stimuli as high as 1.7 T can be administered. Experiments with a simple multicellular organism, the nematodeCaenorhabditis elegans, revealed that intermittent exposure to the magnetic fields modestly inhibited the animal's reproduction as well as its post-embryonic development, and caused a marked but transient derangement in its locomotory behavior. Available evidence indicates that alternating high magnetic fields can elicit both chronic and acute biological effects, but that the effects may be well tolerated or compensated for by the living organism.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Trees 13 (1999), S. 138-151 
    ISSN: 0931-1890
    Keywords: Key words Cytoskeleton ; Immunocytochemistry ; Model systems ; Populus ; Secondary vascular system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Trees represent a, probably the, major component of the biosphere and have a unique place in the history of Mankind. One of their most fascinating features is the process of secondary growth which is effected principally by the secondary vascular system, the developmental continuum of secondary phloem, vascular cambium, and secondary xylem. However, for too long assumptions about the developmental biology of trees have had to be based upon studies of primary growth systems within annual, herbaceous species because study of the secondary vascular system had been largely ignored. Even when attempts are made to understand some of the most fundamental features of the secondary vascular system, such as xylogenesis, the current model system, isolated Zinnia mesophyll cells, is not entirely appropriate to the situation in the intact tree. Some deficiencies of the Zinnia system are discussed, and the advantages of the genus Populus as a model for study of the hardwood secondary vascular system are considered. Some of the new approaches which are poised to lead to significant advances in our knowledge of the cell bio-logy of the secondary vascular system of trees – spe-cifically of the cell wall, the plasmalemma, and the cytoskeleton – are discussed. The value of one of these new techniques – immunocytochemistry – is demonstrated by a consideration of recent work on the role of the cytoskeleton in the hardwood secondary vascular system.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 106 (1996), S. 9-17 
    ISSN: 1432-119X
    Keywords: Silver enhancement ; Immunogold-silver staining ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The immunogold silver staining method (IGSS) is widely used as a sensitive and specific immunohistochemical visualisation technique. IGSS involves the specific deposition of metallic silver at the site of immunogold labelling and provides a means of visualisation at low magnification by light or electron microscopy. Silver developers for IGSS rapidly deposit metallic silver only at the site of heavy metals, including gold and silver, because of their catalytic activity. The developing solution contains the silver ions and reducing agent necessary for this reaction. Using different silver salts as ion donors and by selecting an appropriate temperature and pH, visible amounts of silver can be deposited in a few minutes at the site of colloidal gold labelling while little non-specific background deposition occurs. Inclusion of protective colloids in the solution can also be used to control the reaction. Although studies of the chemical basis of silver deposition around unlabelled colloidal gold date back to 1939, immunogold enhancement by silver was established in 1983. The IGSS method evolved from the combination of disparate photographic, histochemical and immunogold techniques which have been effectively combined and optimised over the last 10 years to provide a visualisation system which is well suited to many immunohistochemical studies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 106 (1996), S. 9-17 
    ISSN: 1432-119X
    Keywords: Key words Silver enhancement ; Immunogold-silver staining ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The immunogold silver staining method (IGSS) is widely used as a sensitive and specific immunohistochemical visualisation technique. IGSS involves the specific deposition of metallic silver at the site of immunogold labelling and provides a means of visualisation at low magnification by light or electron microscopy. Silver developers for IGSS rapidly deposit metallic silver only at the site of heavy metals, including gold and silver, because of their catalytic activity. The developing solution contains the silver ions and reducing agent necessary for this reaction. Using different silver salts as ion donors and by selecting an appropriate temperature and pH, visible amounts of silver can be deposited in a few minutes at the site of colloidal gold labelling while little non-specific background deposition occurs. Inclusion of protective colloids in the solution can also be used to control the reaction. Although studies of the chemical basis of silver deposition around unlabelled colloidal gold date back to 1939, immunogold enhancement by silver was established in 1983. The IGSS method evolved from the combination of disparate photographic, histochemical and immunogold techniques which have been effectively combined and optimised over the last 10 years to provide a visualisation system which is well suited to many immunohistochemical studies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    ISSN: 1432-1939
    Keywords: Key words Agrostis canina ; CO2 vents ; photosynthesis ; lignification ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The aim of this study was to characterise growth and photosynthetic capacity in plants adapted to long-term contrasting atmospheric CO2 concentrations (C a). Seeds of Agrostis canina L. ssp. monteluccii were collected from a natural CO2 transect in central-western Italy and plants grown in controlled environment chambers at both ambient and elevated CO2 (350 and 700 μmol mol−1) in nutrient-rich soil. Seasonal mean C a at the source of the plant material ranged from 610 to 451 μmol CO2 mol−1, derived from C4 leaf stable carbon isotope discrimination (δ13C). Under chamber conditions, CO2 enrichment stimulated the growth of all populations. However, plants originating from elevated C a exhibited higher initial relative growth rates (RGRs) irrespective of chamber CO2 concentrations and a positive relationship was found between RGR and C a at the seed source. Seed weight was positively correlated with C a, but differences in seed weight were found to explain no more than 34% of the variation in RGRs at elevated CO2. Longer-term experiments (over 98 days) on two populations originating from the extremes of the transect (451 and 610 μmol CO2 mol−1) indicated that differences in growth between populations were maintained when plants were grown at both 350 and 700 μmol CO2 mol−1. Analysis of leaf material revealed an increase in the cell wall fraction (CWF) in plants grown at elevated CO2, with plants originating from high C a exhibiting constitutively lower levels but a variable response in terms of the degree of lignification. In vivo gas exchange measurements revealed no significant differences in light and CO2 saturated rates of photosynthesis and carboxylation efficiency between populations or with CO2 treatment. Moreover, SDS-PAGE/ LISA quantification of leaf ribulose bisphosphate carboxylase/oxygenase (Rubisco) showed no difference in Rubisco content between populations or CO2 treatments. These findings suggest that long-term adaptation to growth at elevated CO2 may be associated with a potential for increased growth, but this does not appear to be linked with differences in the intrinsic capacity for photosynthesis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; URS ; FBP1 Transcription
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have constructed a plasmid, pOV10, which facilitates the introduction of putative upstream activating sequences (UAS) or upstream repressing sequences (URS) from yeast genes into plasmids containing CYC1-lacZ fusions. We have observed that the insertion of yeast sequences from 155 to 195 bp between the UAS and the TATA box of a CYC1-lacZ fusion gene can block β-galactosidase expression. It is suggested that this block is related to the formation of nucleosomes on the DNA.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Mitochondrial synthesis ; Nuclear control ; F1Fo-ATPase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Respiratory-competent nuclear mutants have been isolated which presented a cryosensitive phenotype on a non-fermentative carbon source, due to a dysfunctioning of the mitochondrial F1-Fo ATP synthase which results from a relative defect in subunits 6 and 8 of the Fo sector. Both proteins are mtDNA-encoded, but the defect is due to the simultaneous presence of a mutation in two unlinked nuclear genes (NCA2 and NCA3, for Nuclear Control of ATPase) promoting a modification of the expression of the ATP8-ATP6 co-transcript (formerly denoted AAP1-OLI2). This co-transcript matures at a unique site to give two co-transcripts of 5.2 and 4.6 kb in length: in the mutant, the 5.2-kb co-transcript was greatly lowered. NCA3 was isolated from a wild-type yeast genomic library by genetic complementation. The level of the 5.2-kb transcript, like the synthesis of subunits 6 and 8, was partly restored in the transformed strain. A 1011-nucleotide ORF was identified that encodes an hydrophilic protein of 35417 Da. Disruption of chromosomal DNA within the reading frame promoted a dramatic decrease of the 5.2-kb mRNA but did not abolish the respiratory competence of a wild-type strain. NCA3 is located on chromosome IV and produces a single 1780-b transcript.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    ISSN: 1432-0983
    Keywords: Antimutator ; DDR48 ; Saccharomyces cerevisiae ; Spontaneous mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The antimutator phenotype, reportedly conferred by disruption of the Saccharomyces cerevisiae DDR48 gene, was suggested to affect only a specific spontaneous mutational pathway. We attempted to identify the types of mutation that are DDR48-dependent by determining the specificity of the ddr48 antimutator. However, disruption of DDR48 did not decrease the rates of spontaneous forward mutation in a plasmid-borne copy of the yeast SUP4-o gene, the reversion or suppression of the lys2–1 allele, or forward mutation at the CAN1 locus. Interestingly, the latter gene had been reported previously to be subject to the antimutator effect. DNA sequence analysis of spontaneous SUP4-o mutations arising in DDR48 and ddr48 backgrounds provided no evidence for a reduction in the rates of individual mutational classes. Thus, we were unable to verify that disruption of DDR48 causes an antimutator phenotype.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 27 (1995), S. 509-516 
    ISSN: 1432-0983
    Keywords: Yeast ; Maltose fermentation ; MAL63 ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mal63p is a transcriptional activator for maltose fermentation in Saccharomyces cerevisiae. We have purified it to homogeneity from a yeast strain in which the MAL63 gene is under the control of the GAL1–GAL10 promoter. Purification included fractionation of a whole-cell extract by ion-exchange chromatography, chromatography using both non-specific DNA-affinity (calf thymus), and sequence-specific DNA-affinity chromatography. Mal63p activity was assayed by its binding to a fragment of the MAL61–MAL62 promoter, using both filter-binding and electrophoretic-mobility shift assays. DNase-I footprinting identified a new binding site (site 3) between the two previously known sites (sites 1 and 2). Mal63p is a dimer, and methylation-protection experiments identify the recognition motif as: c/a GC N9 c/a GC/g.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    ISSN: 1432-0983
    Keywords: Key words Omnipotent suppression ; Microtubules ; Respiratory deficiency ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  SUP35 and SUP45 genes determine the accuracy of translation at the stage of termination. We present indirect evidence indicating that these genes may also control some cellular process mediated by microtubules. A majority of sup35 and sup45 suppressor mutations confer supersensitivity to benomyl, the drug which de-polymerizes microtubules. In addition, data correlating phenotypic manifestations of sup45 suppressor mutations, involving sensitivity to benomyl, respiratory deficiency and a suppressor effect, are also presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    ISSN: 1432-0983
    Keywords: Key words D-ribulose-5-phosphate 3-epimerase ; D-ribose-5-phosphate ketol-isomerase ; Pentose-phosphate pathway ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have cloned and characterized the two remaining unknown genes of the non-oxidative part of the pentose-phosphate pathway of Saccharomyces cerevisiae encoding the enzymes D-ribulose-5-phosphate 3-epimerase (Rpe1p) and D-ribose-5-phosphate ketol-isomerase (Rki1p). Rpe1p has an unexpected high specific activity of 2148 mU × (mg protein)–1 in crude extracts. Deletion mutants of RPE1 show no enzyme activity and are unable to grow on D-xylulose. Unexpectedly, haploid rki1 deletion mutants are not viable. Functional expression of RKI1 was demonstrated following an increase of gene dosage in the haploid rki1 deletion mutant, which restored viability and specific D-ribose-5-phosphate ketol-isomerase activity. Both enzymes show high similarity to the deduced protein sequences of various open reading frames, expressed sequence tags or cDNAs from different organisms.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 30 (1996), S. 461-468 
    ISSN: 1432-0983
    Keywords: Keywords DNA repair ; Methylation damage ; Epistasis analysis ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The major genotoxicity of methyl methanesulfonate (MMS) is due to the production of a lethal 3-methyladenine (3MeA) lesion. An alkylation-specific base-excision repair pathway in yeast is initiated by a Mag1 3MeA DNA glycosylase that removes the damaged base, followed by an Apn1 apurinic/ apyrimidinic endonuclease that cleaves the DNA strand at the abasic site for subsequent repair. MMS is also regarded as a radiomimetic agent, since a number of DNA radiation-repair mutants are also sensitive to MMS. To understand how these radiation-repair genes are involved in DNA methylation repair, we performed an epistatic analysis by combining yeast mag1 and apn1 mutations with mutations involved in each of the RAD3, RAD6 and RAD52 groups. We found that cells carrying rad6, rad18, rad50 and rad52 single mutations are far more sensitive to killing by MMS than the mag1 mutant, that double mutants were much more sensitive than either of the corresponding single mutants, and that the effects of the double mutants were either additive or synergistic, suggesting that post-replication and recombination-repair pathways recognize either the same lesions as MAG1 and APN1, or else some differ- ent lesions produced by MMS treatment. Lesions handled by recombination and post replication repair are not simply 3MeA, since over-expression of the MAG1 gene does not offset the loss of these pathways. Based on the above analyses, we discuss possible mechanisms for the repair of methylation damage by various pathways.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; pso4-1 mutant Sporulation ; DNA repair ; Meiotic recombination Induced mutagenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have evaluated the effect of the Saccharomyces cerevisiae pso4-1 mutation in sporulation and DNA repair during meiosis. We have found that pso4-1 cells were arrested in an early step of meiosis, before premeiotic DNA synthesis, and hence did not produce spores. These results suggest that the PSO4 gene may act at the start point of the cell cycle, as do some SPO and CDC genes. The pso4-1 mutant cells are specifically sensitive to 8-MOP- and 3-CPs-photoinduced lesions, and are found to be severely affected in meiotic recombination as well as impaired in the mutagenic response, as previously described for mitosis. This means that the PSO4 gene is important for the repair 8-MOP-photoinduced lesions, mainly double-strand breaks, and the processing of these lesions into recombinogenic intermediates.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Chromosome copy numbers ; Ploidy probes ; Industrial yeasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Methods have been devised for analyzing chromosome copy numbers in S. cerevisiae strains that may be polyploid or aneuploid, as is apparent in the case of many industrial strains. The initial step involved transformation of a strain with an integrative “ploidy probe” transplacement fragment that enable the copy number of the targeted chromosomal locus to be determined via genomic Southern blotting and quantitative probe hybridization. Dual probe co-hybridization to Southern genomic DNA blots was used to extend such locus copy number determinations to other loci within the same chromosome, thereby screening for internal consistency along the length of the chromosome. This approach was also used to extend the analysis to other chromosomes in the genome. The method was established and verified with euploid series laboratory strains and then used to examine chromosome copy numbers in three industrial strains. One brewing strain apparently contained three copies of the chromosomes tested, whilst another brewing and a baking strain showed evidence of aneuploidy.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    ISSN: 1432-0983
    Keywords: Key words Transcriptional regulation ; Phospholipid biosynthesis ; Saccharomyces cerevisiae ; INO2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Expression of structural genes of phospholipid biosynthesis in yeast is mediated by the inositol/choline-responsive element (ICRE). ICRE-dependent gene activation, requiring the regulatory genes INO2 and INO4, is repressed in the presence of the phospholipid precursors inositol and choline. INO2 and, to a less extent, INO4 are positively autoregulated by functional ICRE sequences in the respective upstream regions. However, an INO2 allele devoid of its ICRE functionally complemented an ino2 mutation and completely restored inositol/choline regulation of Ino2p-dependent reporter genes. Low-level expression of INO2 and INO4 genes, each under control of the heterologous MET25 promoter, did not alter the regulatory pattern of target genes. Thus, upstream regions of INO2 and INO4 are not crucial for transcriptional control of ICRE-dependent genes by inositol and choline. Interestingly, over-expression of INO2, but not of INO4, counteracted repression by phospholipid precursors. Possibly, a functional antagonism between INO2 and a negative regulator is the key event responsible for repression or de-repression.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    ISSN: 1432-0983
    Keywords: Biocontrol ; Secretion ; Chitinase ; Expression cloning ; Saccharomyces cerevisiae ; Trichoderma harzianum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A novel endochitinase agar-plate assay has been developed and used to identify 11 full-length cDNAs encoding endochitinase I (ENC I) from aTrichoderma harzianum cDNA library by expression in yeast. The 1473-bpchil cDNA encodes a 424-residue precursor protein including both a signal sequence and a propeptide. The deduced ENC I amino-acid sequence is homologous to other fungal and bacterial chitinases, and the enzyme cross-reacts with a polyclonal antiserum raised against chitinase A1 fromBacillus circulans. TheT. harzianum endochitinase I was secreted into the culture medium by the yeastSaccharomyces cerevisiae in a functionally active form. The purified recombinant enzyme had a molecular mass of 44 kDa, an isoelectric point of 6.3, a pH optimum of 7.0 and a temperature optimum of 20 °C.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    ISSN: 1432-0983
    Keywords: Aspergillus kawachii ; β-xylanase ; Expression ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract First-strand cDNA was prepared from mRNA isolated from Aspergillus kawachii IFO4308 and the β-xylanase gene (xynC) amplified by using the polymerase chain reaction (PCR) technique. This gene was inserted between the yeast phosphoglycerate kinase (PGK1) gene promoter (PGK1 p) and terminator (PGK1 T) sequences. The PGK1 P-xynC-PGK1 T construct (designated XYN3) was cloned into a multicopy episomal plasmid and the XYN3 gene was expressed in Saccharomyces cerevisiae. Functional β-xylanase (Xyn3) was produced and secreted by the recombinant yeast. Xyn3 was stable between 30 and 50°C, and the optimum temperature and pH were shown to be at 60°C and lower than pH3, respectively. An autoselective fur1::LEU2 XYN3 recombinant strain was developed that allowed β-xylanase production at a level of 300 nkat/ml in a non-selective complex medium.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    ISSN: 1432-0983
    Keywords: Key words Cysteine uptake ; Amino-acid permeases ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Uptake by Saccharomyces cerevisiae of the sulphur-containing amino acid L-cysteine was found to be non-saturable under various conditions, and uptake kinetics suggested the existence of two or more transport systems in addition to the general amino-acid permease, Gap1p. Overexpression studies identified BAP2, BAP3, AGP1 and GNP1 as genes encoding transporters of cysteine. Uptake studies with disruption mutants confirmed this, and identified two additional genes for transporters of cysteine, TAT1 and TAT2, both very homologous to BAP2, BAP3, AGP1 and GNP1. While Gap1p and Agp1p appear to be the main cysteine transporters on the non-repressing nitrogen source proline, Bap2p, Bap3p, Tat1p, Tat2p, Agp1p and Gnp1p are all important for cysteine uptake on ammonium-based medium. Furthermore, whereas Bap2p, Bap3p, Tat1p and Tat2p seem most important under amino acid-rich conditions, Agp1p contributes significantly when only ammonium is present, and Gnp1p only contributes under the latter condition.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 34 (1998), S. 269-279 
    ISSN: 1432-0983
    Keywords: Key words Double-strand breaks ; Heteroduplex DNA ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Spontaneous and double-strand break (DSB)-induced gene conversion in Saccharomyces cerevisiae was assayed using non-tandem chromosomal direct repeat crosses and plasmid × chromosome crosses. Each cross involved identical ura3 alleles marked with phenotypically silent restriction fragment length polymorphic (RFLP) mutations at approximately 100-bp intervals. DSBs introduced in vivo at HO sites in one allele stimulated recombination to Ura+ by more than two orders of magnitude. Spontaneous gene-conversion products were isolated from a related strain lacking a functional HO nuclease gene. The multiple markers did not appear to influence the frequency of direct repeat deletions for spontaneous or DSB-induced events. DSB-induced conversion reflected efficient mismatch repair of heteroduplex DNA. Conversion frequencies of equidistant markers on opposites sides of the DSB were similar in the direct repeat cross. In contrast, markers 5′ of the DSB (promoter-proximal) converted more often than 3′ markers in plasmid × chromosome crosses, a possible consequence of crossing-over associated with long conversion tracts. With direct repeats, bidirectional tracts (extending 5′ and 3′ of the DSB) occurred twice as often as in a plasmid × chromosome cross in which DSBs were introduced into the plasmid-borne allele. A key difference between the direct-repeat and plasmid×chromosome crosses is that the ends of a broken plasmid are linked, whereas the ends of a broken chromosome are unlinked. We tested whether linkage of ends influenced tract directionality using a second plasmid × chromosome cross in which DSBs were introduced into the chromosomal allele and found few bidirectional tracts. Thus, chromosome environment, but not linkage of ends, influences tract directionality. The similar tract spectra of the two plasmid × chromosome crosses suggest that similar mechanisms are involved whether recombination is initiated by DSBs in plasmid or chromosomal alleles.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 27 (1995), S. 306-308 
    ISSN: 1432-0983
    Keywords: Gene deletion ; Open reading frame ; Saccharomyces cerevisiae ; Polymerase chain reaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The classical disruption method for yeast genes is by using in vitro deletion of the gene of interest, or of a part of it, with restriction enzymes. We are now routinely using a strategy that takes advantage of polymerase chain reactions (PCRs) which amplify large pieces of DNA. Since this approach results in a complete, precise deletion of the open reading frame, which is replaced by a unique restriction site, the ligated PCR can be used for the insertion of different markers of for two-step gene disruptions without an inserted marker. As we have now used this strategy for the deletion of more than ten genes we have in this report included some hints based on our experience.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    ISSN: 1432-0983
    Keywords: Multidrug resistance ; Candida albicans ; Saccharomyces cerevisiae ; ABC transporters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract By functional complementation of a PDR5 null mutant of Saccharomyces cervisiae, we have cloned and sequenced the multidrug-resistance gene CDR1 of Candida albicans. Transformation by CDR1 of a PDR5-disrupted host hypersensitive to cycloheximide and chloramphenicol resulted in resistance to cycloheximide, chloramphenicol and other drugs, such as the antifungal miconazole, with collateral hypersensitivity to oligomycin, nystatin and 2,4 dinitrophenol. Our results also demonstrate the presence of several PDR5 complementing genes in C. albicans, displaying multidrug-resistance patterns different from PDR5 and CDR1. The nucleotide sequence of CDR1 revealed that, like PDR5, it encodes a putative membrane pump belonging to the ABC (ATP-binding cassette) superfamily. CDR1 encodes a 1501-residue protein of 169.9 kDa whose predicted structural organization is characterized by two homologous halves, each comprising a hydrophobic region with a set of six transmembrane stretches, preceded by a hydrophilic nucleotide binding fold.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    ISSN: 1432-0983
    Keywords: Heat-shock response ; Multidrug resistance ; AP-1 homolog ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have examined whether the stress-induced transcriptional activation ofYDR1/PDR5/STS1 is mediated by yAP-1 and yAP-2. Of the stresses examined, heat shock-induced, rapid and transient PDR5 expression became very low in ayap1 yap2 double-gene disruptant, indicating that the yAP proteins mediate the response. Similar results were obtained withSNQ2, a close homologue ofPDR5. A set of 5′-truncation derivatives of thePDR5 gene identified the region from −484 to −434 as being sufficient for the response. A sequence similar to the yAP-1 recognition element recently identified in the stress-responsive yeast genes was found in this region and in the 5′-flanking sequences ofSNQ2.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    ISSN: 1432-0983
    Keywords: Autonomously replicating sequence ; Auxotrophy ; Schizosaccharomyces pombe ; Saccharomyces cerevisiae ; Cloning vector ; Selectable marker ; HIS/his ; LYS/lys
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three new S. pombe plasmids are described. Plasmids pSP3 and pSP4 are two Schizosaccharomyces pombe ars1 multicopy vectors with the Saccharomyces cerevisiae HIS3 or LYS2 genes as selectable markers. They complement the S. pombe his5-303 or lys1-131 mutations, respectively. Plasmid pSPars1 is a vector carrying the S. pombe ars1 and a unique NdeI site which allows the introduction of any selectable marker therefore bringing a unified vector backbone for the construction of new S. pombe/S. cerevisiae/E. coli shuttle vectors. These plasmids permit classical molecular genetic techniques to be performed directly.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    ISSN: 1432-0983
    Keywords: Key words Biocontrol ; Secretion ; Chitinase ; Expression cloning ; Saccharomyces cerevisiae ; Trichoderma harzianum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A novel endochitinase agar-plate assay has been developed and used to identify 11 full-length cDNAs encoding endochitinase I (ENC I) from a Trichoderma harzianum cDNA library by expression in yeast. The 1473-bp chi1 cDNA encodes a 424-residue precursor protein including both a signal sequence and a propeptide. The deduced ENC I amino-acid sequence is homologous to other fungal and bacterial chitinases, and the enzyme cross-reacts with a polyclonal antiserum raised against chitinase A1 from Bacillus circulans. The T. harzianum endochitinase I was secreted into the culture medium by the yeast Saccharomyces cerevisiae in a functionally active form. The purified recombinant enzyme had a molecular mass of 44 kDa, an isoelectric point of 6.3, a pH optimum of 7.0 and a temperature optimum of 20 °C.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 35 (1999), S. 77-81 
    ISSN: 1432-0983
    Keywords: Key words Adaptive mutations ; 6-N-hydroxylaminopurine ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The frequency of reversion in a histidine-requiring mutant of Saccharomyces cerevisiae increases about ten-fold in stationary cells during histidine starvation. Histidine starvation enhances a similar frequency of reversion in a tryptophan-requiring mutant. Starvation, therefore, enhances mutation frequencies in a non-adaptive manner. The base analogue 6-N-hydroxylaminopurine (HAP) added prior to plating on medium with limited histidine strongly increases reversion of the histidine mutant. HAP-induced reversion increases further in stationary starving cells with the same kinetics as that which increases spontaneous reversion. Adding HAP to the stationary starving cells does not produce any effect.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    ISSN: 1432-0983
    Keywords: Key words Heteroduplex repair ; Strand discrimina-tion ; Strand interruptions ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Site-directed mutagenesis was used to construct yeast centromere plasmids in which a strand nick or gap could be placed 5′ or 3′, on either strand, to a reporter gene (SUP4-o) carrying defined base mismatches. The plasmids were then transformed into yeast cells and the direction and efficiency of mismatch repair were assayed by scoring colouring of the transformant colonies. Strands that were nicked were consistently corrected more often than intact strands, but the effect was very small. However, placement of a small gap at the same positions as the nicks resulted in a marked increase in selection for the gapped strand and an enhanced efficiency of mismatch repair. Both the preference for the gapped strand and correction of the mismatch were offset by deletion of the mismatch repair gene PMS1. Together, the results suggest that strand interruptions can direct intracellular mismatch correction of plasmid-borne base mispairs in yeast.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 36 (1999), S. 256-261 
    ISSN: 1432-0983
    Keywords: Key wordsFLO8 ; Transcriptional regulation ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract It is thought that the FLO8 gene encodes a transcriptional activator of the dominant flocculation gene FLO1 in Saccharomycescerevisiae. To determine other genes which are regulated by FLO8, a detailed comparison of the transcripts from the FLO8 and Δflo8 strains was carried out. In addition to the FLO1 gene, it was found that transcription of the FLO11 and STA1 genes is positively regulated by FLO8. In flo8 strains, not only transcripts of the FLO11, STA1, and FLO1 genes but also invasive growth, extracellular glucoamylase production, and flocculation were undetected. From these results, it is suggested that FLO8 regulates these characteristics via the transcriptional regulation of the FLO11, STA1, and FLO1 genes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 1432-0983
    Keywords: Calmodulin ; Calmodulin-dependent protein kinase II ; Heat shock response ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We show here that yeast mutants lacking calmodulin-dependent protein kinase II fail to fully acquire induced thermotolerance. A similar result was also obtained with mutants depending solely on either the N-terminal half or the C-terminal half of calmodulin. These findings indicate that both calmodulin-dependent protein kinase II and calmodulin are required for induced thermotolerance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    ISSN: 1432-0983
    Keywords: Glycolysis ; Transcriptional activation ; Saccharomyces cerevisiae ; Chromatin structure ; Glucose induction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 31 (1997), S. 401-407 
    ISSN: 1432-0983
    Keywords: Key words Cytochrome oxidase ; Mitochondrial localization ; PET1402/OXA1 ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The yeast PET1402/OXA1 gene encoding a 44.8-kDa protein is required for mitochondrial biogenesis. Substitution of Leu240 to serine in the protein results in an accumulation of the precursor form of the mitochondrially encoded subunit 2 of cytochrome oxidase (Cox2) and temperature-sensitive respiration. This temperature sensitivity can be suppressed by a mutation in the cox2 gene changing Ala189 of the Cox2 protein to proline. In the cox2-ts1402 double mutant respiration is restored without removal of the Cox2 pre-sequence. The suppression suggests an interaction of the Pet1402 protein with the cytochrome oxidase complex. Antibodies raised against the predicted C-terminus and the tagged N-terminus of the Pet1402 protein reacted with a 37-kDa polypeptide. This protein, present in the mitochondrial fraction, is localized within the inner membrane. The difference in size can be explained by the removal of the predicted mitochondrial-targeting sequence from the Pet1402 protein. The mitochondrial localization of the protein points to a direct interaction with the cytochrome oxidase complex.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Omnipotent suppression ; Nonsense suppression ; SUP45
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Using a plasmid-based termination-read-through assay, the sal4-2 conditional-lethal (temperature-sensitive) allele of the SUP45 (SAL4) gene was shown to enhance the efficiency of the weak ochre suppressor tRNA SUQ5 some 10-fold at 30°C. Additionally, this allele increased the suppressor efficiency of SRM2-2, a weak tRNAGln ochre suppressor, indicating that the allosuppressor phenotype is not SUQ5-specific. A sup + sal4-2 strain also showed a temperature-dependent omnipotent suppressor phenotype, enhancing readthrough of all three termination codons. Combining the sal4-2 allele with an efficient tRNA nonsense suppressor (SUP4) increased the temperature-sensitivity of that strain, indicating that enhanced nonsense suppressor levels contribute to the conditional-lethality conferred by the sal4-2 allele. However, UGA suppression levels in a sup + sal4-2 strain following a shift to the non-permissive temperature reached a maximum significantly below that exhibited by a non-temperature sensitive SUP4 suppressor strain. Enhanced nonsense suppression may not therefore be the primary cause of the conditional-lethality of this allele. These data indicate a role for Sup45p in translation termination, and possibly in an additional, as yet unidentified, cellular process.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 27 (1995), S. 427-434 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Oxidative stress ; Osmotic stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Although oxidative stress is involved in many human diseases, little is known of its molecular basis in eukaryotes. In a genetic approach, S. cerevisiae was used to identify elements involved in oxidative stress. By using hydrogen peroxide as an agent for oxidative stress, 34 mutants were identified. All mutants were recessive and fell into 16 complementation groups (pos1 to pos16 for peroxide sensitivity). They corresponded to single mutations as shown by a 2:2 segregation pattern. Enzymes reportedly involved in oxidative stress, such as glucose-6-phosphate dehydrogenase, glutathione reductase, superoxide dismutase, as well as glutathione concentrations, were investigated in wild-type and mutant-cells. One complementation group lacked glucose-6-phosphate dehydrogenase and was shown to be allelic to the glucose-6-phosphate dehydrogenase structural gene ZWF1/MET19. In other mutants all enzymes supposedly involved in oxidative-stress resistance were still present. However, several mutants showed strongly elevated levels of glutathione reductase, gluconate-6-phosphate dehydrogenase and glucose-6-phosphate dehydrogenase. One complementation group, pos9, was highly sensitive to oxidative stress and revealed the same growth phenotype as the previously described yap1/par1 mutant coding for the yeast homologue of mammalian transcriptional activator protein, c-Jun, of the proto-oncogenic AP-1 complex. However, unlike par1 mutants, which showed diminished activities of oxidative-stress enzymes and glutathion level, the pos9 mutants did not reveal any such changes. In contrast to other recombinants between pos mutations and par1, the sensitivity did not further increase in par1 pos9 recombinants, which may indicate that both mutations belong to the same regulating circuit. Interestingly, ten complementation groups were, in parallel, sensitive to osmotic stress, and one mutant allele revealed increased heat sensitivity. Our results indicate that a surprisingly large number of genes seem to be involved in oxidative-stress resistance and a possible overlap exists between osmotic stress and other stress reactions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    ISSN: 1432-0983
    Keywords: Key wordsPSO5/RAD16 ; Saccharomyces cerevisiae ; Nucleotide excision repair ; Oxidative stress ; Ribonucleotide reductase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The expression of β-galactosidase from DNA damage-inducible RNR2-lacZ and RNR3-lacZ fusion constructs was compared in wild-type (WT) and pso5/rad16 mutant strains after treatment with five mutagens/oxidative stressors. While exposure to the mutagens UVC, 4NQO and H2O2 induced expression of the RNR2-lacZ and RNR3-lacZ fusion constructs in two WT strains, treatment with the two oxidative stressors tBOOH and paraquat did not. In the pso5-1 mutant induction of RNR2-lacZ was largely reduced after UVC and H2O2 while there was no significant induction of β-galactosidase expression after 4NQO treatment for this construct. For RNR3-lacZ there was strongly reduced expression of pso5-1 after UVC and 4NQO while H2O2 failed to induce expression of β-galactosidase. In the WT strains the ranking of the inducing power of the mutagens at 90% survival (as measured in the pso5-1 mutant) was 4NQO〉UVC〉H2O2. Though the WT strains were clearly more resistant that the pso5-1 mutant to the two oxidative stressors paraquat and tBOOH, these substances failed to significantly enhance expression of the RNR2-lacZ and RNR3-lacZ fusion constructs in both the WT and the pso5-1 mutant. Our data suggest that Pso5p/Rad16p has a function in the signal transducing pathway controlling DNA damage-inducible components of nucleotide excision repair.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    ISSN: 1432-0983
    Keywords: Key words Zinc-finger protein ; Nuclear localization ; Immuno electron microscopy ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In previous studies the AZF1 gene has been identified as a second high-copy number suppressor for a special mutant of the gene for the mitochondrial core enzyme of RNA polymerase. The first high-copy number suppressor of this mutant turned out to be the specificity factor MTF1 for mitochondrial transcription. Up to now, the influence of AZF1 on mitochondrial transcription, its precise localization in the cell and the regulation of its expression has not been determined. The putative protein contains a long stretch of poly-asparagine amino acids and a typical zinc-finger domain for DNA binding. These characteristic structural features were used to create the abbreviation AZF1 (Asparagine-rich Zinc Finger protein). An initial computer analysis of the sequence gave no conclusive results for the presence of a mitochondrial import sequence or a typical nuclear-targeting sequence. A recent more-detailed analysis identified a possible nuclear localization signal in the middle of the protein. Disruption of the gene shows no effect on plates with glucose-rich medium or glycerol. In this report a specific polyclonal antibody against Azf1p was prepared and used in cell-fractionation experiments and in electron-microscopic studies. Both of these clearly demonstrate that the AZF1 protein is localized exclusively in the nucleus of the yeast cell. Northern analysis for the expression of the AZF1 messenger RNA under different growth conditions was therefore performed to obtain new insights into the regulation of this gene. Together with the respective protein-expression analysis these data demonstrate that Azf1p is preferentially synthezised in higher amounts under non-fermentable growth conditions. Over-expression of Azf1p in the yeast cell does not influence the expression level of the mitochondrial transcription factor Mtf1p, indicating that the influence of Azf1p on the suppression of the special mitochondrial RNA polymerase mutant is an indirect one. Subcellular investigation of the deletion mutant by electron microscopy identifies specific ultrastructural cell-division defects in comparison to the wild-type.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    ISSN: 1432-0983
    Keywords: Key words Psoralen sensitivity ; Cytochrome oxidase ; Saccharomyces cerevisiae ; Oxidative stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The yeast gene PSO7 was cloned from a genomic library by complementation of the pso7-1 mutant's sensitivity phenotype to 4-nitroquinoline-1-oxide (4NQO). Sequence analysis revealed that PSO7 is allelic to the 1.1-kb ORF of the yeast gene COX11 which is located on chromosome XVI and encodes a protein of 28-kDa localized in the inner mitochondrial membrane. Allelism of PSO7/COX11 was verified by non-complementation of 4NQO-sensitivity in diploids homo- and hetero-allelic for the pso7-1 and cox11::TRP1 mutant alleles. Sensitivity to 4NQO was the same in exponentially growing cells of the pso7-1 mutant and the cox11::TRP1 disruptant. Allelism of COX11 and PSO7 indicates that the pso7 mutant's sensitivity to photoactivated 3-carbethoxypsoralen and to 4NQO is not caused by defective DNA repair, but rather is due to an altered metabolism of the pro-mutagen 4NQO in the absence of cytochrome oxidase (Cox) in pso7-1/cox11::TRP1 mutants/disruptants. Lack of Cox might also lead to a higher reactivity of the active oxygen species produced by photoactivated 3-carbethoxypsoralen. The metabolic state of the cells is important for their sensitivity phenotype since the largest enhancement of sensitivity to 4NQO between wild-type (WT) and the pso7 mutant occurs in exponentially growing cells, while cells in stationary phase or growing cells in phosphate buffer have the same 4NQO resistance, irrespective of their WT/mutant status. Strains containing the pso7-1 or cox11::TRP1 mutant allele were also sensitive to the oxidative stress-generating agents H2O2 and paraquat. Mutant pso7-1, as well as disruptant cox11::TRP1, harboured mitochondria that in comparison to WT contained less than 5% and no detectable Cox activity, respectively.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    ISSN: 1432-0983
    Keywords: Key words Mitotic recombination ; DNA double-strand breaks ; Saccharomyces cerevisiae ; 8-Methoxypsoralen plus UVA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mitotic recombination within the ARG4 gene of Saccharomyces cerevisiae was analysed after treatment of cells with the recombinogenic agent 8-methoxypsoralen (8-MOP) plus UVA. The appearance of DNA double-strand breaks (DSBs) in the ARG4 region during post-treatment incubation was also tested. The results obtained after 8-MOP plus UVA treatment indicate that in mitotic cells: (1) recombination at the ARG4 locus is increased 30 – 500 fold per survivor depending on the strains and the doses employed, (2) the increase of recombination results essentially from gene conversion events which involve the RV site located in the 5′ region of the ARG4 gene twice as often as the Bgl site at the 3′ end, (3) depending on 8-MOP/UVA dose, ectopic gene conversion is associated with reciprocal translocation, (4) DSBs occur preferentially in the ARG 5′ region during post-treatment incubation, as well as in other intergenic regions containing both promoters or/and terminators of transcription, and (5) changes in sequence content in the 5′ region of ARG4, which influences positions and frequencies of DSBs formed during repair, are correlated with a modification of the local chromatin structure.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    ISSN: 1432-0983
    Keywords: 2-deoxyglucose ; 2-deoxyglucose-6P phosphatase ; Catabolite repression ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 2-deoxyglucose (2-DOG), a non-metabolize analogue of glucose, is taken up by yeast using the same transporter(s) as glucose and is phosphorylated by hexokinases producing 2-deoxyglucose-6-P. We found that in DOG R yeasts, 2-DOG was not able to trigger glucose repression, even at concentrations of 0.5%. This result suggests that the specific 2-DOG-6P phosphatase, the enzyme responsible for the DOG R phenotype, may be involved in inhibiting the process of catabolite repression mediated by 2-DOG
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Kluyveromyces lactis ; Transcriptional regulation ; Catabolite repression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Promoter regions of the KlQCR7, KlQCR8 and KlCYC1 genes, coding for subunits of the bc 1-complex and cytochrome c respectively, in the shortterm Crabtree-negative yeast Kluyveromyces lactis differ markedly in sequence from their Saccharomyces cerevisiae counterparts. They have, however, conserved very similar configurations of binding-site motifs for various transcription factors known to be involved in global and carbon-source regulation in S. cerevisiae. To investigate the carbon source-dependent expression of these genes in K. lactis, we have carried out medium-shift experiments and determined transcript levels during the shifts. In sharp contrast to the situation in S. cerevisiae, the level of expression in K. lactis is not affected when glucose is added to a non-fermentable carbon-source medium. However, the genes are not constitutively expressed, but become significantly induced when the cells are shifted from glucose to a nonfermentable carbon source. Finally, induction of transcriptional activation does not occur in media containing both glucose and non-femmentable carbon sources.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    ISSN: 1432-0983
    Keywords: Key words Cytochrome b ; Mutants ; Mitochondria ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The nucleotide changes present in a group of five cytochrome b mit– mutants were analyzed at the sequence level. Two single-base changes were found: one (M10-152) generated a nonsense codon in the first exon while the other (M8-181) created a missense substitution in the second exon. The other mutants all have multiple (three) substitutions that either resulted in a missense mutation in a coding region (M17-162) or else changed nucleotides in the last intron of the gene, so blocking its excision (M6-200 and M8-53). The synthesis of mitochondrial polypeptides and the steady state concentration of the complex-III subunits were examined. The Rieske protein and the core-4 and core-5 subunits were much reduced in all mutants. Consequently the overall stability of complex III is very sensitive even to amino-acid substitutions in the cytochrome b protein. Mutant M8-53 provides direct evidence for the proposed role of the P9.1 stem in the core structure of the group-I type last intron of this gene.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    ISSN: 1432-0983
    Keywords: Key wordsβ-glucosidase ; Candida wickerhamii ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The yeast Candida wickerhamii exports a cell-associated β-glucosidase that is active against cellobiose and all soluble cellodextrins. Because of its unique ability to tolerate end-product inhibition by glucose, the bglB gene that encodes this enzyme was previously cloned and sequenced in this laboratory. Using several different promoters and constructs, bglB was expressed in the hosts Escherichia coli, Pichia pastoris, and Saccharomyces cerevisiae. Expression was initially performed in E. coli using either the lacZ or tac promoter. This resulted in intracellular expression of the BglB protein with the protein being rapidly fragmented. Secretion and glycosylation of active β-glucosidase was achieved with several different S. cerevisiae constructs utilizing either the adh1 or the gal1 promoter on 2-µ replicating plasmids. When either the invertase (Suc2) or the BglB secretion signal was used, BglB protein remained associated with the cell wall and appeared to be hyperglycosylated. Expression in P. pastoris was also examined to determine if higher activity and expression could be achieved in a yeast host that usually does not hyperglycosylate. Using the alcohol oxidase promoter in conjunction with either the pho1 or the α-factor secretion signal, the recombinant enzyme was successfully secreted and glycosylated in P. pastoris. However, levels of protein expression from the chromosomally integrated vector were insufficient to detect activity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    ISSN: 1432-0983
    Keywords: Key words Bleomycin hydrolase ; Saccharomyces cerevisiae ; Thiol proteases ; Protein amphitropism ; Processing of glycosyl-phosphatidylinositol (GPI) anchor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Bleomycin hydrolase, Blh1p, from yeast was co-purified with Gce1p, a cAMP-binding ectoprotein, anchored to the plasma membrane by a glycosyl-phosphatidylinositol (GPI) anchor. Blh1p is a hydrophilic thiol protease lacking transmembrane domains. We have used polyclonal antibodies to study the topology of the over-expressed protein in yeast and have found that it is amphitropic. Part of Blh1p is associated with plasma membranes, and most of the rest occurs in the cytosol. Both the growth conditions and calcium were found to have minor influences on the topology of Blh1p, in that glucose and the earth-alkali ion slightly enhanced recruitment to the membrane. We have examined the possibility that co-purification of Blh1p with Gce1p has a functional basis, and have observed that over-expression of BLH1 in yeast leads to an acceleration of the glucose-induced amphiphilic to hydrophilic conversion of Gce1p, wherein Blh1p could either directly catalyse the proteolytic removal of the polar headgroup of the GPI anchor subsequent to an initial lipolytic cleavage by a GPI-specific phospholipase C or indirectly modulate the reaction. The data show that a thiol protease is involved, but point to an indirect role of Blh1p in GPI processing. Proteases with similar or overlapping substrate specificity are likely to exist, since deletion of BLH1 neither entails a growth defect on any carbon source tested, nor the loss of proteolytic processing of the GPI anchor of Gce1p. Reduced proteolytic GPI processing is, however, observed in the blh1 mutant and the corresponding acceleration in the respective BLH1 multi-copy transformant.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    ISSN: 1432-0983
    Keywords: Key wordsSaccharomyces bayanus ; Saccharomyces cerevisiae ; Translocation ; Speciation ; Duplicated gene ; RPL2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract By a genomic comparison of two sibling yeasts, Saccharomyces bayanus and S. cerevisiae, we previously demonstrated that chromosomes II and IV of S. cerevisiae were rearranged into chromosomes 12 and 14 of S. bayanus or vice versa. In the present study we have delimited the translocation break sites in chromosomes II and IV by Southern hybridization using DNA fragments of S. cerevisiae cosmid clones as probes. The results suggest that the reciprocal translocation of chromosomes II and IV had occurred at duplicated RPL2 loci. Furthermore, the translocation sites in S. bayanus were confirmed by the cloning and sequence analysis of the regions flanking RPL2 loci. Several genes in the regions flanking the RPL2 loci were present in the order expected for a translocation at these loci between the two species. These results indicated that the reciprocal translocation between chromosomes II and IV was generated by homologous recombination at duplicated RPL2 loci on the two chromosomes. Therefore, we propose that duplicated genes or duplicated regions play an important role in altering genomic organization during the speciation of S. bayanus and S. cerevisiae.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    ISSN: 1432-0983
    Keywords: Key words Fructose-1 ; 6-bisphosphatase ; Catabolite repression ; Gluconeogenesis ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have investigated the effect of different carbon sources and of different mutations on the capacity of two elements, UAS1 and UAS2, from the promoter of the FBP1 gene to form specific DNA-protein complexes and to activate expression of a reporter gene. The complexes are observed with nuclear extracts from yeast derepressed on glycerol or ethanol. When hxk2 mutants are grown on glucose the nuclear extracts are able to complex UAS1 but not UAS2, while for wild-type cells grown on galactose only the complex with UAS2 is formed. In contrast, in vivo the operation of both UASs is high in ethanol, moderate to low in glycerol, and negligible in galactose; no expression is observed in glucose even in a hxk2 background. There is no effect of a MIG1 deletion, either in the formation of DNA-protein complexes or on the expression of reporter genes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; HEM13 regulation ; Heme and oxygen ; CYP1, ROX1, SSN6, TUP1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Saccharomyces cerevisiae HEM13 gene codes for coproporphyrinogen oxidase (CPO), an oxygen-requiring enzyme catalysing the sixth step of heme biosynthesis. Its transcription is increased 40–50-fold in response to oxygen- or heme-deficiency. We have analyzed CPO activity and HEM13 mRNA levels in a set of isogenic strains carrying single or double deletions of the CYP1 (HAP1), ROX1, SSN6, or TUPI genes. The cells were grown in the presence or absence of oxygen and under heme-deficiency (hem1Δ background). Both Rox1p and Cyp1p partially repressed HEM13 in aerobic heme-sufficient cells, probably in an independent manner. In the absence of heme, Cyp1p activated HEM13 and strongly repressed ROX1, allowing de-repression of HEM13. Cyp1p had no effect on HEM13 expression in anaerobic cells. Deletions of SSN6 or TUP1 dramatically de-repressed HEM13 in aerobic cells. A series of deletions in the HEM13 promoter identified at least four regulatory regions that are required for HEM13 regulation. Two regions, containing motifs similar to the Rox1p consensus sequences, act as repression sites under aerobic growth. The two other sites act as activation sequences required for full induction under oxygen- or heme-deficiency. Taken together, these results suggest that induction of HEM13 occurs in part through relief of repression exerted by Rox1p and Cyp1p, and in part by activation mediated partly by Cyp1p under heme-deficiency and by unknown factors under oxygen-deficiency.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    ISSN: 1432-0983
    Keywords: α-Amylase ; Lipomyces kononenkoae ; LKA1 ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A highly active α-amylase (76 250 Da) secreted by the raw starch-degrading yeast Lipomyces kononenkoae strain IGC4052B was purified and characterized. Using high performance liquid chromatography (HPLC), end-product analysis indicated that the L. kononenkoae α-amylase acted by endo-hydrolysis on glucose polymers containing α-1,4 and α-1,6 bonds, producing mainly maltose, maltotriose and maltotetraose. The following NH2-terminal amino acids were determined for the purified enzyme: Asp-Cys-Thr-Thr-Val-Thr-Val-Leu-Ser-Ser-Pro-Glu-Ser-Val-Thr-Gly. The L. kononenkoae α-amylase-encoding gene (LKA1), previously cloned as a cDNA fragment, was expressed in Saccharomyces cerevisiae under the control of the PGK1 promoter. The native signal sequence efficiently directed the secretion of the glycosylated protein in S. cerevisiae. De-glycosylation of the enzyme indicated that post-translational glycosylation is different in S. cerevisiae from that in L. kononenkoae. Zymogram analysis indicated that glycosylation of the protein in S. cerevisiae had a negative effect on enzyme activity. Southern-blot analysis revealed that there is only a single LKA1 gene present in the genome of L. kononenkoae.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 29 (1996), S. 227-233 
    ISSN: 1432-0983
    Keywords: Trichoderma reesei ; β-Glucosidase ; Cellulase ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An intronless form of thebgl1 gene encoding an extracellularβ-glucosidase fromTrichoderma reesei was expressed in the yeast Saccharomyces cerevisiae under the control of the yeast GAL 1 promoter. Transformation of a yeast strain with this vector resulted in transformants that produce and secrete activeβ-glucosidase into the growth medium. Additionally, active recombinantβ-glucosidase protein was shown to be localized predominantly in the periplasmic space by using ap-nitrophenylβ-D-glycoside hydrolysis assay against fractionated yeast cells. The apparent size of the recombinant enzyme was 10–15 kDa larger than that of the native form. Treatment of the recombinantβ-glucosidase with endoglycosidase-H indicated the apparent increase in size was due to N-linked glycosylation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 29 (1996), S. 227-233 
    ISSN: 1432-0983
    Keywords: Key words  Trichoderma reesei ; β-Glucosidase ; Cellulase ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract   An intronless form of the bgl1 gene encoding an extracellular β-glucosidase from Trichoderma reesei was expressed in the yeast Saccharomyces cerevisiae under the control of the yeast GAL1 promoter. Transformation of a yeast strain with this vector resulted in transformants that produce and secrete active β-glucosidase into the growth medium. Additionally, active recombinant β-glucosidase protein was shown to be localized predominantly in the periplasmic space by using a p-nitrophenyl β-D-glycoside hydrolysis assay against fractionated yeast cells. The apparent size of the recombinant enzyme was 10–15 kDa larger than that of the native form. Treatment of the recombinant β-glucosidase with endoglycosidase-H indicated the apparent increase in size was due to N-linked glycosylation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    ISSN: 1432-0983
    Keywords: Key words Adenine biosynthesis ; ade8-18 ; ade2 mutations ; Red/white colony color assay ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the yeast Saccharomyces cerevisiae the ade2, and/or the ade1, mutation in the adenine biosynthetic pathway leads to the accumulation of a cell-limited red pigment, while epistatic mutations in the same pathway, i.e. ade8, preclude this phenomenon, resulting in normal white colonies. The shift in color from red to white (or vice versa) with a combination of appropriate wild-type and mutant alleles of the adenine-pathway genes has been widely utilized as a non-selective phenotype to visualise and quantify the occurrence of various genetic events such as recombination, conversion and aneuploidy. It has provided an invaluable tool for the study of gene dosage and plasmid stability. In competition experiments between disrupted ade2, ade8-18 transformants carrying either a functional or non-functional episomal ADE8 gene, we verified that white ade8 ade2 cells show a remarkable selective advantage over red ade2 cells, with important implications on the use of this assay for the monitoring of genetic events. The accumulation of the red pigment in ade2 cells is likely to be the cause for impaired growth in these cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 34 (1998), S. 138-145 
    ISSN: 1432-0983
    Keywords: Key words Cytochrome c oxidase ; Saccharomyces cerevisiae ; Complex assembly
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We report on the molecular and biochemical analysis of a set of 13 respiratory deficient mutants of Saccharomyces cerevisiae which are specifically altered in COX1, the gene encoding the subunit Cox1p of cytochrome c oxidase. DNA sequence analysis shows that three are due to frameshift mutations, two to nonsense mutations, and eight to missense mutations. All, except the missense mutant S157L, have impaired electron transfer and respiratory activity. Analysis of the mitochondrial translation products shows that when Cox1p is absent, Cox2p and Cox3p are still synthesized. In the missense mutants, the steady state levels in the mitochondrial membranes of the three mitochondrially encoded subunits Cox1p, Cox2p and Cox3p and the nuclear-encoded subunit Cox4p are reduced. In the frameshift and nonsense mutants, Cox1p is absent and Cox2p, Cox3p and Cox4p are considerably decreased or undetectable. A comparison of the steady state levels of Cox1p through Cox4p in the COX1, COX2, COX3 and COX4 mutants shows the interdependance of the accumulation of these four subunits in the mitochondrial membranes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    ISSN: 1432-0983
    Keywords: Key words RAD6 ; Ubiquitin-conjugating enzymes ; Saccharomyces cerevisiae ; Arabidopsis thaliana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract AtUBC2 of Arabidopsis thaliana encodes a structural homolog of the RAD6 gene of Saccharomyces cerevisiae with approximately 65% identical amino acids. Like structural homologs from other organisms, AtUBC2 lacks the carboxyl-terminal extension of mostly acidic amino acids which is present in Rad6p. AtUBC2 was expressed in S. cerevisiae rad6 mutants. It was found to partially complement the UV sensitivity and reduced growth rate of rad6 mutants at elevated temperatures. AtUBC2 however, has no apparent influence on the degradation of N-end rule substrates in the heterologous host.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Springer
    Journal of population economics 9 (1996), S. 415-428 
    ISSN: 1432-1475
    Keywords: H42 ; J 13 ; O 11 ; Fertility ; growth ; public education and health
    Source: Springer Online Journal Archives 1860-2000
    Topics: Sociology , Economics
    Notes: Abstract This paper considers the implications of the financing of government services to children when fertility decisions are endogenously determined. In particular, it is shown that when the services are financed by taxation, the equilibrium outcome is biased away from the socially preferred result. The bias results in higher fertility rates and lower economic growth rates than the efficient social optimum. This arises because each household internalizes the benefits, but not the costs of the tax-financed services. We consider alternative methods of financing the public provision of services and find that a combination of taxation and vouchers can eliminate the bias in the equilibrium outcome.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Springer
    Journal of population economics 11 (1998), S. 273-291 
    ISSN: 1432-1475
    Keywords: JEL classification: F22 ; O3 ; J61 ; Key words: Immigration ; assimilation ; growth ; diversity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Sociology , Economics
    Notes: Abstract. This paper analyzes the welfare effects of immigration and its subsequent effect on ethnic diversity in a model featuring human capital spillovers which depend on the degree of ethnic heterogeneity, variation rates of time preference across individuals and endogenous levels of immigration and assimilation. In the model, an increase in ethnic diversity reduces the spillovers effect for the majority. Nonetheless, immigration can be welfare improving for the majority ethnic group even if it increases the degree of diversity as long as it raises the average human capital level and/or growth rate by increasing the proportion of people with low rates of time preference. However, if an economy is too homogenous, it will not be able to attract immigrants. Finally, if the level of immigration is not too high, then immigration also raises the net benefits to assimilation which leads to a more homogenous economy.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Springer
    Journal of population economics 11 (1998), S. 517-534 
    ISSN: 1432-1475
    Keywords: Key words: Fertility ; mortality ; growth ; JEL classification: J13 ; O41
    Source: Springer Online Journal Archives 1860-2000
    Topics: Sociology , Economics
    Notes: Abstract. Economic and demographic outcomes are determined jointly in a choice-theoretic model of fertility, mortality and capital accumulation. There is an endogenous population of reproductive agents who belong to dynastic families of overlapping generations connected through altruism. In addition to choosing savings and births, parents may reduce (infant) deaths by incurring expenditures on health-care which is also provided by the government. A generalised production technology accounts for long-run endogenous growth with short-run transitional dynamics. The analysis yields testable time series and cross-section implications which accord with the empirical evidence on the relationship between demography and development.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    Springer
    Journal of population economics 9 (1996), S. 415-428 
    ISSN: 1432-1475
    Keywords: Key words: Fertility ; growth ; public education and health
    Source: Springer Online Journal Archives 1860-2000
    Topics: Sociology , Economics
    Notes: Abstract. This paper considers the implications of the financing of government services to children when fertility decisions are endogenously determined. In particular, it is shown that when the services are financed by taxation, the equilibrium outcome is biased away from the socially preferred result. The bias results in higher fertility rates and lower economic growth rates than the efficient social optimum. This arises because each household internalizes the benefits, but not the costs of the tax-financed services. We consider alternative methods of financing the public provision of services and find that a combination of taxation and vouchers can eliminate the bias in the equilibrium outcome. JEL classification: H42, J13, O11
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    ISSN: 1432-072X
    Keywords: Key words Protein phosphorylation ; ATP-Pi exchange ; Light-harvesting complexes ; Reaction center ; Photosynthesis ; Photomorphogenesis ; Membrane ; growth ; Polypeptide insertion ; Phospho-amino esters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Membranes of Rhodobacter capsulatus strain U43 (pTX35) showed qualitatively very similar phosphorylation patterns under in vitro and in vivo conditions. In vitro, it was irrelevant whether the phosphate source was orthophosphate or ATP. Inhibitors of electron transport did not inhibit light-harvesting complex I (LHIα) (B870) polypeptide phosphorylation, except for o-phenanthroline, which was strongly inhibitory. Redox conditions regulated the amount of protein phosphorylated; external redox potentials between +200 and +300 mV promoted the reaction. Phosphorylation was inhibited by uncouplers such as carbonyl cyanide m-chlorophenyl hydrazone and nigericin plus valinomycin plus potassium ions. Inhibitors of the H+-ATPase were also inhibitory when the phosphate source was [32P]Pi or [γ-32P]ATP. From these results, it was concluded that an operative reaction center, a coupled membrane, and external redox potentials higher than +200 mV are required for optimum LHIα phosphorylation. We also demonstrated that phosphorylation of LHIα polypeptide occurs before insertion into the membrane and that phosphate is preferentially incorporated into specific domains within the cytoplasmic membrane. Intracytoplasmic membranes, identified here as light membranes, were found to contain a dephosphorylated LHIα polypeptide.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    ISSN: 1432-072X
    Keywords: Isocitrate lyase ; n-Alkane-utilizable yeast ; Candida tropicalis ; Saccharomyces cerevisiae ; Promoters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The upstream region of the isocitrate lyase gene (UPR-ICL, 1530bp) of an n-alkane-utilizable yeast, Candida tropicalis, induced gene expression in another yeast, Saccharomyces cerevisiae, when the yeasts were grown on acetate. Surprisingly, UPR-ICL displayed the same regulatory function in the bacterium Escherichia coli when grown on acetate. We determined the interesting nucleotide sequence of UPR-ICL. The deletion analysis of UPR-ICL in both cells revealed the presence of two distinct promoters: one was localized at-394 to-379 and regulated gene expression in S. cerevisiae; the other was tocated near the initiation codon and regulated gene expression in E. coli. The two promoter sequences were similar, but not identical to regulatory elements that have been previously reported in S. cerevisiae and E. coli, respectively. Accordingly, the possibility of novel regulatory mechanisms could not be excluded. This is an interesting example of the presence of distinct cis-acting regulatory elements responsible for the induction of gene expression in one gene by acetate in both S. cerevisiae and E. coli. Preservation of such promoters through evolution is also discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    ISSN: 1432-072X
    Keywords: Key words Isocitrate lyase ; n-Alkane-utilizable yeast ; Candida tropicalis ; Saccharomyces cerevisiae ; Promoters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The upstream region of the isocitrate lyase gene (UPR-ICL, 1530bp) of an n-alkane-utilizable yeast, Candida tropicalis, induced gene expression in another yeast, Saccharomyces cerevisiae, when the yeasts were grown on acetate. Surprisingly, UPR-ICL displayed the same regulatory function in the bacterium Escherichia coli when grown on acetate. We determined the interesting nucleotide sequence of UPR-ICL. The deletion analysis of UPR-ICL in both cells revealed the presence of two distinct promoters: one was localized at –394 to –379 and regulated gene expression in S. cerevisiae; the other was located near the initiation codon and regulated gene expression in E. coli. The two promoter sequences were similar, but not identical to regulatory elements that have been previously reported in S. cerevisiae and E. coli, respectively. Accordingly, the possibility of novel regulatory mechanisms could not be excluded. This is an interesting example of the presence of distinct cis-acting regulatory elements responsible for the induction of gene expression in one gene by acetate in both S. cerevisiae and E. coli. Preservation of such promoters through evolution is also discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    ISSN: 1432-072X
    Keywords: Key words Plasma membrane H+-ATPase ; Saccharomyces cerevisiae ; Low pH ; PMA1 gene expression ; PMA2 gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cells of Saccharomyces cerevisiae grown in media with an initial pH of 2.5–6.0, acidified with a strong acid (HCl), exhibited the highest plasma membrane H+-ATPase-specific activity at an initial pH of 6.0. At a lower pH (above pH 2.5) ATPase activity (62–83% of the maximum level) still allowed optimal growth. At pH 2.5, ATPase activity was about 30% of the maximum value and growth was impaired. Quantitative immunoassays showed that the content of ATPase protein in the plasma membrane was similar across the entire pH range tested, although slightly lower at pH 2.5. The decrease of plasma membrane ATPase activity in cells grown at low pH was partially accounted for by its in vitro stability, which decreased sharply at pH below 5.5, although the reduction of activity was far below the values expected from in vitro measurements. Yeast growth under acid stress changed the pattern of gene expression observed at optimal pH. The level of mRNA from the essential plasma-membrane-ATPase-encoding gene PMA1 was reduced by 50% in cells grown at pH 2.5 as compared with cells grown at the optimal pH 5.0, although the content of ATPase in the plasma membrane was only modestly reduced. As observed in response to other kinds of stress, the PMA2 promoter at the optimal pH was up to eightfold more efficient in cells grown at pH 2.5, although it remained several hundred times less efficient than that of the PMA1 gene.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    ISSN: 1432-072X
    Keywords: Key words Plasma membrane H+-ATPase ; PMA1 ; ATPase ; PMA2 ATPase ; Saccharomyces cerevisiae ; Copper stress ; Copper tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The major yeast plasma membrane H+-ATPase is encoded by the essential PMA 1 gene. The PMA 2 gene encodes an H+-ATPase that is functionally interchangeable with the one encoded by PMA 1 , but it is expressed at a much lower level than the PMA 1 gene and it is not essential. Using genetically manipulated strains of Saccharomyces cerevisiae that exclusively synthesize PMA1 ATPase or PMA2 ATPase under control of the PMA1 promoter, we found that yeast cultivation under mild copper stress leads to a similar activation of PMA2 and PMA1 isoforms. At high inhibitory copper concentrations (close to the maximum that allowed growth), ATPase activity was reduced from maximal levels; this decrease in activity was less important for PMA2 ATPase than for PMA1 ATPase. The higher tolerance to high copper stress of the artificial strain synthesizing PMA2 ATPase exclusively, as compared to that synthesizing solely PMA1 ATPase, correlated both with the lower sensitivity of PMA2 ATPase to the deleterious effects of copper in vivo and with its higher apparent affinity for MgATP, and suggests that plasma membrane H+-ATPase activity plays a role in yeast tolerance to copper.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    ISSN: 1432-072X
    Keywords: Key words Plasma membrane H+-ATPase ; Saccharomyces cerevisiae ; Copper stress ; PMA1 ; PMA2 ; Gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cells of Saccharomyces cerevisiae exibited a more active plasma membrane H+-ATPase during growth in media supplemented with CuSO4 concentrations equal to or below 1 mM than did cells cultivated in the absence of copper stress. Maximal specific activities were found with 0.5 mM CuSO4. ATPase activity declined when cells were grown with higher concentrations up to 1.5 mM (the maximal concentration that allowed growth), probably due to severe disorganization of plasma membrane. Cu2+-induced maximal activation was reflected in an increase of V max (approximately threefold) and in the slight decrease of the K m for MgATP (from 0.93 ± 0.13 to 0.65 ± 0.16 mM). The expression of the gene encoding the essential plasma membrane ATPase (PMA1) was reduced with a dose-dependent pattern in cells grown with inhibitory concentrations of copper, while the weakly expressed PMA2 gene promoter was moderately more efficient in cells cultivated under mild copper stress (1.5-fold maximal activation). ATPase was activated by copper despite the slightly lower content of ATPase protein in the plasma membrane of Cu2+-grown cells and the powerful inhibitory effect of Cu2+ in vitro.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    Springer
    Invertebrate neuroscience 1 (1995), S. 199-206 
    ISSN: 1439-1104
    Keywords: phospholipase C ; inositol phosphate ; invertebrate vision ; olfaction ; growth ; differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: abstract Phosphatidylinositol-specific phospholipase C (PLC) is a family of enzymes that occupy a pivotal role in one of the largest classes of cellular signaling pathways known. Mammalian PLC enzymes have been divided into four major classes and a variety of subclasses based on their structural characteristics and immunological differences. There have been five invertebrate PLC-encoding genes cloned thus far and these fall within three of the four major classes used in categorizing mammalian PLC. Four of these invertebrate genes have been cloned fromDrosophila melanogaster and one is fromArtemia, a brine shrimp. Structural characteristics of the invertebrate enzymes include the presence of highly conserved Box X and Box Y domains found in major types of mammalian PLC as well as novel features. Two of the invertebrate PLC genes encode multiple splice-variant subtypes which is a newly emerging level of diversity observed in mammalian enzymes. Studies of the invertebrate PLCs have contributed to the identification of the physiological functions of individual isozymes. These identified roles include cellular processes such as phototransduction, olfaction, cell growth and differentiation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 14 (1995), S. 514-522 
    ISSN: 1476-5535
    Keywords: Saccharomyces cerevisiae ; Molecular taxonomy ; Classification ; Alcoholic fermentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Archaic speculations and firmly established legends regarding the origin of the yeastSaccharomyces cerevisiae and related species are revisited in light of past and recent ecological evidence pointing to a strict association with artificial, man-made environments such as wineries and fermentation plants. The nomenclature within this industrially important group is also discussed in view of the modifications imposed from application of molecular techniques to classification.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 16 (1996), S. 102-109 
    ISSN: 1476-5535
    Keywords: Millet ; Pennisetum typhoides ; liquefaction ; saccharification ; baker's yeast ; Saccharomyces cerevisiae ; fermentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A fermentation medium based on millet (Pennisetum typhoides) flour hydrolysate and a four-phase feeding strategy for fed-batch production of baker's yeast,Saccharomyces cerevisiae, are presented. Millet flour was prepared by dry-milling and sieving of whole grain. A 25% (w/v) flour mash was liquefied with a thermostable 1,4-α-d-glucanohydrolase (EC 3.2.1.1) in the presence of 100 ppm Ca2+, at 80°C, pH 6.1–6.3, for 1 h. The liquefied mash was saccharified with 1,4-α-d-glucan glucohydrolase (EC 3.2.1.3) at 55°C, pH 5.5, for 2 h. An average of 75% of the flour was hydrolysed and about 82% of the hydrolysate was glucose. The feeding profile, which was based on a model with desired specific growth rate range of 0.18–0.23 h−1, biomass yield coefficient of 0.5 g g−1 and feed substrate concentration of 200 g L−1, was implemented manually using the millet flour hydrolysate in test experiments and glucose feed in control experiments. The fermentation off-gas was analyzed on-line by mass spectrometry for the calculation of carbon dioxide production rate, oxygen up-take rate and the respiratory quotient. Off-line determination of biomass, ethanol and glucose were done, respectively, by dry weight, gas chromatography and spectrophotometry. Cell mass concentrations of 49.9–51.9 g L−1 were achieved in all experiments within 27 h of which the last 15 h were in the fedbatch mode. The average biomass yields for the millet flour and glucose media were 0.48 and 0.49 g g−1, respectively. No significant differences were observed between the dough-leavening activities of the products of the test and the control media and a commercial preparation of instant active dry yeast. Millet flour hydrolysate was established to be a satisfactory low cost replacement for glucose in the production of baking quality yeast.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 52 (1998), S. 537-542 
    ISSN: 1572-8943
    Keywords: fractals ; growth ; nucleation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The author presents a model based on multi-step nucleation for the heterogeneous decompositions described by nucleation and growth phenomena, taking into account the fractal nature of the nuclei.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    Springer
    Aquaculture international 6 (1998), S. 1-17 
    ISSN: 1573-143X
    Keywords: Atlantic salmon (Salmo salar) ; Condition factor ; feeding regimes ; growth ; proximate composition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of different feeding methods on growth and slaughter traits of Atlantic salmon, Salmo salar, have been examined. Swimming activity associated with feeding was greatest amongst fish fed using automatic feeders, intermediate amongst those fed predetermined rations by hand, and least in groups of fish fed to satiation twice per day. Fish fed to satiation ate more and grew faster than did those provided with rations predicted to support high rates of growth, but the fish fed to satiation had higher feed:gain ratios than those given predetermined rations as two meals per day. The muscle tissues of the fish fed to satiation had higher lipid (%) and lower moisture (%) contents than did those of the fish fed the predetermined rations, but differences in muscle composition could be accounted for by differences in the size of the fish. Lipid was positively, and moisture negatively, correlated with fish size, whereas per cent protein and dress-out losses were little influenced by fish size and feeding regime. The fish fed to satiation were slightly heavier for a given length than those in the other groups. There was, however, no evidence that the largest fish had the highest condition factor, nor could condition factor be used to predict per cent lipid in the muscle tissue. Size variation increased in all groups of fish, and this was, in part, due to the cessation of growth of maturing individuals. Size variation was, however, most marked in the groups fed using automatic feeders, suggesting that interindividual competition for food was greatest amongst these fish.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    ISSN: 1573-143X
    Keywords: bighead carp (Aristichthys nobilis) ; growth ; Laguna Lake ; salinity tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Bighead carp (Aristichthys nobilis Oshima) fry of various ages (11, 18, and 35 days post-hatch) were exposed to the low salinities encountered during the annual intrusion of seawater in Laguna Lake, Philippines. Practical indices of salinity tolerance assessed the effect of a 96 h direct exposure to low salinities (0–16‰). Mean (MST) and median survival times (MST50) of fry decreased as salinity of rearing medium increased. Younger fry were less able to tolerate exposure to these salinities than their older cohorts. Median lethal salinity after 96 h (MLS) revealed higher tolerance among 35–day old fry (7.6‰) than 11 (2.3‰) and 18–day old fry (6.0‰), demonstrating that survival in saline water depends on their age at initial exposure to low salinities. Mean body weight of 18–day old fry reared in 0 and 2‰ for 3 and 4 weeks was higher than for those reared in 4 and 6‰ for the same period. Growth over these periods was inversely related with the range of salinities tested. These results demonstrate that, despite their known stenohalinity, bighead carp fry possess some degree of osmoregulatory capability, allowing them to survive and grow in lakes subjected periodically to saltwater inflow.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    Springer
    Aquaculture international 7 (1999), S. 287-293 
    ISSN: 1573-143X
    Keywords: bone mineralization ; calcium requirement ; feed efficiency ; growth ; semi-purified diet ; tiger puffer (Takifugu rubripes)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Juvenile tiger puffer (Takifugu rubripes) were fed semi-purified diets with graded levels (0–0.40%) of calcium (Ca) supplements for 8 weeks at a temperature of 23.0–25.5 °C. At the end of the feeding experiment, average final body weight increased with increasing dietary Ca levels. A diet without Ca supplement resulted in poor average final body weight and 0.05% dietary Ca supplement could not significantly improve the growth. However, supplemental Ca levels of 0.10–0.40% significantly increased growth. Dietary Ca supplements of 0.10% or more also improved the feed efficiency in tiger puffer. Ca and phosphorus contents of the bone were independent of dietary Ca supplements. However, 0.40% Ca in the diet decreased the zinc and manganese contents of bone. Results indicated that supplemental Ca levels of 0.10–0.20% in a semi-purified diet were required to maintain normal growth, feed utilization and bone mineralization of tiger puffer.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    Springer
    Molecular and cellular biochemistry 146 (1995), S. 63-69 
    ISSN: 1573-4919
    Keywords: rice bran oil ; growth ; plasma lipids ; fatty acids ; lipoproteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effects of feeding two levels of rice bran oil (RBO) on the growth, lipid parameters, and fatty acid composition of the plasma and liver of rats (Wistar strain) were compared with those produced on animals which had been fed the same levels of peanut oil (PNO). The control animals were fed synthetic diets containing 5 and 20% peanut oil (PNO) and the experimental groups were fed similar diets, containing the same level of rice bran oil (RBO). There was no significant difference with respect to the organ weights between the control and the experimental groups. In general, groups fed 20% oil gained more weight than groups fed 5% oil. The animals which received rice bran oil in their diet had, in general, comparatively lower levels of cholesterol, triglycerides and phospholipids. On the other hand, animals receiving 20% rice bran oil in their diet, showed an increase of 20% in high density lipoproteins (HDL-C), within 18 weeks (p〈0.05), when compared to the animals fed with peanut oil. Similarly, low density lipoprotein cholesterol (LDL-C) and very low density lipoprotein cholesterol (VLDL-C) were lower in RBO-fed groups, than in the PNO-fed groups. There was, however, no significant differences in the cholesterol/phospholipid (C/P) ratio of the two groups. Analysis of plasma and of liver fatty acids indicated, in a general way, the type of fat consumed. There were no significant difference in the P/S ratio, nor any in the oleic/linoleic, oleic/stearic, palmitoleic/palmitic, oleic/palmitic, and oleic/palmitoleic ratios. Furthermore, levels of saturated (SAFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids were identical in both the groups. Thus, our results suggest that feeding a high level of rice bran oil (RBO) has no deleterious effect on the growth and blood lipid profile of rats.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    Springer
    Molecular and cellular biochemistry 169 (1997), S. 95-106 
    ISSN: 1573-4919
    Keywords: Saccharomyces cerevisiae ; N-glycosylation ; dolichol pathway ; ALG7 ; post-transcriptional regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The yeast ALG7 gene functions by initiating the synthesis of the dolichol-linked oligosaccharide precursor and plays an important role in the control of protein N-glycosylation. The levels of ALG7 multiple transcripts are modulated by the physiological status of the cell and environmental cues, and deregulation of their abundance is deleterious to several cellular functions. Since ALG7 mRNAs are unstable, we investigated the role of these transcripts' half-lives in determining their steady-state levels. Using a temperature-sensitive RNA polymerase II mutant, we demonstrate that increased stability was the primary determinant of higher ALG7 mRNA abundance in response to glucose limitation or treatment with tunicamycin. In contrast, at the G1/G0 transition point, changes in the decay rates were inversely related to ALG7 transcript accumulation: the decreased abundance of ALG7 mRNAs following exit from the mitotic cycle was associated with lengthening of the decay rates, while their increased accumulation after growth stimulation correlated with decreased stability. This suggests that, depending on the circumstance, mRNA half-lives can either directly determine the level of ALG7 transcript accumulation or oppose regulatory changes at other control levels.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    Springer
    Molecular and cellular biochemistry 184 (1998), S. 67-79 
    ISSN: 1573-4919
    Keywords: Saccharomyces cerevisiae ; spheroplast ; permeabilization ; mitochondria ; oxidative phosphorylation ; porin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract In this work, we first compared yeast mitochondrial oxidative metabolism at different levels of organization: whole cells (C), spheroplasts (S), permeabilized spheroplasts (PS) or isolated mitochondria (M). At present, S are more suitable for use than C for biochemical techniques such as fast extraction of metabolises and permeabilization. We show here that respiratory rates of S with various substrates are similar to C, which demonstrate that they are adapted to yeast bioenergetic studies. It appeared from ethanol metabolism ± NAD++ or NADH respiratory rates on PS that ethanol metabolism was largely cytosolic; moreover, the activity of NADH dehydrogenase was lesser in the case of PS than in S. By comparing PS and M, the biggest difference concerned the respiratory rates of pyruvate and pyruvate-malate, which were much lower for M. Thus mitochondria preparation caused an unidentified loss involved directly in pyruvate metabolism. When the respiratory rate was lowered as a consequence of a high kinetic control of oxidative activity upstream from the respiratory chain, a similar correlation between the increase in ATP/O and decrease in respiratory rate was observed. So, the intrinsic uncoupling of proton pumps is not a particularity of M. Secondly, we demonstrate the existence of a mechanism of retarded diffusion in yeast similar to that already observed in permeabilized mammalian cells for ADP. Such a mechanism also occurs in yeast for several respiratory substrates: the K0.5 for each substrate toward the respiration rate in PS always exceeds that for M. It is proposed that such a discrepancy is due to a restriction of metabolite movement across the outer mitochondrial membrane in permeabilized cells, i.e. regulation of the substrate permeability through porin channels. In the porin-deficient yeast mutant, the K0.5 for NADH is not significantly different in either M or PS and is comparable to that of the parent strain PS. This result confirms that this retarded diffusion is essentially due to the opening-closing of the porin channel.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    Springer
    Molecular and cellular biochemistry 190 (1999), S. 47-54 
    ISSN: 1573-4919
    Keywords: calmodulin ; yeast calmodulin ; Ca2+ binding ; Ca2+ binding protein ; Saccharomyces cerevisiae ; interdomain interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Calmodulin of Saccharomyces cerevisiae has different Ca2+ binding properties from other calmodulins. We previously reported that the maximum number of Ca2+ binding was 3 mol/mol and the fourth binding site was defective, which was different from 4 mol/mol for others. Their macroscopic dissociation constants suggested the cooperative three Ca2+ bindings rather than a pair of cooperative two Ca2+ bindings of ordinary calmodulin. Here we present evidence for yeast calmodulin showing the intramolecular close interaction between the N-terminal half domain and the C-terminal half domain, while the two domains of ordinary calmodulin are independent of each other. We will discuss the relationship of the shape and the shape change caused by the Ca2+ binding to the enzyme activation in yeast. The functional feature of calmodulin in yeast will also be considered, which might be different from the one of vertebrate calmodulin.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    ISSN: 1573-4919
    Keywords: NADH oxidase ; plasma membranes ; growth ; retinol ; retinoids ; HeLa cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Several retinoids, both natural and synthetic, were evaluated for their ability to modulate NADH oxidase activity of plasma membranes of cultured HeLa cells and the growth of HeLa cells in culture. Both NADH oxidase activity and the growth of cells were inhibited by the naturally-occurring retinoids all trans-retinoic acid (tretinoin) and retinol as well as by the synthetic retinoids, trans-acitretin, 13-cis-acitretin, etretinate and arotonoid ethylester (Ro 13-6298). For all retinoids tested, inhibition of NADH oxidase activity and inhibition of growth were correlated closely. With tretinoin, etretinate and arotonoid ethylester, NADH oxidase activity and cell growth were inhibited in parallel in proportion to the logarithm of retinoid concentration over the range of concentrations 10-8 to 10-5 M. Approximately 70% inhibition of both NADH oxidase activity and growth was reached at 10 µM. With retinol, trans-acitretin and 13-cis-acitretin, inhibition of NADH oxidase activity and growth also were correlated but maximum inhibition of both was about 40% at 10 µM. The possibility is suggested that inhibition of the plasma membrane NADH oxidase activity by retinoids may be related to their mechanism of inhibition of growth of HeLa cells in culture. (Mol Cell Biochem 166: 101-109, 1997)
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    ISSN: 1573-4919
    Keywords: heart ; postnatal development ; sarcoplasmic reticulum ; phospholamban ; calcium transport ; spontaneously hypertensive rats ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract This comparative study investigates the relationship between sarcoplasmic reticulum (SR) calcium(Ca2+)-ATPase transport activity and phospholamban (PLB) phosphorylation in whole cardiac homogenates of spo`ntaneously hypertensive rats (SHR) and their parent, normotensive Wistar Kyoto (WKY) strain during early postnatal development at days 1, 3, 6, 12 and at day 40 to ascertain any difference in SR Ca2+ handling before the onset of hypertension. At day 1, the rate of homogenate oxalate-supported Ca2+ uptake was significantly higher in SHR than in WKY (0.25 ± 0.02 vs 0.12 ± 0.01 nmoles Ca2+/mg wet ventricular weight/min, respectively; p 〈 0.001). This interstrain difference disappeared with further developmental increase in SR Ca2+ transport. Western Blot analysis and a semiquantitative ELISA did not reveal any difference in the amount of immunoreactive PLB (per mg of total tissue protein) between strains at any of the ages studied. In addition, levels of phosphorylated PLB formed in vitro in the presence of radiolabelled ATP and catalytic (C) subunit of protein kinase A did not differ between SHR and WKY at days 1, 3, 6 and 12. At day 40, C subunit-catalyzed formation of 32P-PLB was reduced by 66% (p 〈 0.001) in SHR when compared to age-matched WKY In the early postnatal period between day 1 and 12 SR Ca2+-transport values were linearly related to the respective 32P-PLB levels of both SHR and WKY rats. The results indicate that cardiac SR of SHR can sequester Ca2+ at a much higher rate immediately after birth compared to WKY rats. The disappearance of this interstrain difference with further development suggests that some endogenous neuroendocrine or nutritional factor(s) from the hypertensive mother may exert an influence upon the developing heart in utero resulting in a transiently advanced maturation of the SR Ca2+ transport function in SHR pups at the time of birth.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    ISSN: 1573-4919
    Keywords: NADH oxidase ; protein disulfide-thiol interchange ; dipyridyl-dithio substrates ; plasma membrane ; auxin ; 2,4-dichlorophenoxyacetic acid ; growth ; plant (Glycine max)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Dipyridyl-dithio substrates were cleaved by isolated vesicles of plasma membranes prepared from etiolated hypocotyls of soybean. The cleavage was stimulated by auxins at physiological concentrations. The substrates utilized were principally 2,2′-dithiodippyrine (DTP) and 6,6′-dithiodinicotinic acid (DTNA). The DTP generated 2 moles of 2-pyridinethione whereas the 6,6′-dithiodinicotinic acid generated 2 moles of 6-nicotinylthionine. Both products absorbed at 340 nm. The auxin herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D) stimulated the activity approximately 2-fold to a maximum at about 10 μM. Concentrations of 2,4-D greater than 100 μM inhibited the activity. Indole-3-acetic acid stimulated the activity as well. The growth-inactive auxin, 2,3-dichlorophenoxyacetic acid (2,3-D), was without effect. DTNA cleavage correlated with oxidation of NADH and reduction of protein disulfide bonds reported earlier in terms of location at the external plasma membrane surface, absolute specific activity, pH dependence and auxin specificity. The dipyridyl-dithio substrates provide, for the first time, a direct measure of the disulfide-thiol interchange activity of the protein previously measured only indirectly as an auxin-dependent ability of isolated plasma membrane vesicles to restore activity to scrambled and inactive RNase.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Springer
    Molecular and cellular biochemistry 202 (1999), S. 109-118 
    ISSN: 1573-4919
    Keywords: NF1 mutations ; IRA1 ; Saccharomyces cerevisiae ; RAS2 ; GAP activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The 2818 amino acids of neurofibromin, the product of the human NF1 gene, include a 230 amino acid Ras-GAP related domain (GRD). Functions which may be associated with the rest of the protein remain unknown. However, many NF1 mutations in neurofibromatosis 1 patients are found downstream of the GRD, suggesting that the C-terminal region of the protein is also functionally important. Since the C-terminal region of neurofibromin encompassing these mutations is homologous with the corresponding regions in the two Saccharomyces cerevisiae Ras-GAPs, Ira1p and Ira2p, we chose yeast as a model system for functional exploration of this region (Ira-C region). Three missense mutations that affect the Ira-C region of NF1 were used as a model for the mutagenesis of IRA1. The yeast phenotypes of heat shock sensitivity, iodine staining, sporulation efficiency, pseudohyphae formation, and GAP activity were scored. Even though none of the mutations directly affected the Ira1p-GRD, mutations at two of the three sites resulted in a decrease in the GAP activity present in ira1 cells. The third mutation appeared to disassociate the phenotypes of sporulation ability and GAP activity. This and other evidence suggest an effector function for Ira1p.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    ISSN: 1573-4919
    Keywords: annexin V ; cardiac myocyte ; growth ; hypertrophy ; heart
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Recently it was shown that annexin V is the most prominent member of the annexin family in the adult heart [1]. Amongst others, annexin V has been suggested to play a role in developmental processes. The aim of the present study was to explore whether in the heart annexin V content and localization change during maturational and hypertrophic growth, in order to obtain indications that annexin V is involved in cardiac growth processes. First, in the intact rat heart annexin V content and localization were studied during perinatal development. It was clearly demonstrated that annexin V content in total heart transiently increased in the first week after birth, from 0.79 ± 0.06 µg/mg protein at l day before birth to a peak value of 1.24 ± 0.08 µg/mg protein 6 days after birth, whereafter annexin V protein levels declined to a value of 0.70 ± 0.06 µg/mg protein at 84 days after birth (p 〈 0.05). Differences in annexin V content were also observed between myocytes isolated from neonatal and adult hearts [0.81 ± 0.09 and 0.17 ± 0.08 µg/mg protein, respectively (p 〈 0.05)]. Moreover, during cardiac maturational growth the subcellular localization of annexin V might change from a cytoplasmic to a more prominent sarcolemmal localization. Second, in vivo hypertrophy induced by aortic coarctation resulted in a marked degree of hypertrophy (22% increase in ventricular weight), but was not associated with a change in annexin V localization or content. The quantitative results obtained with intact hypertrophic rat hearts are supported by findings in neonatal ventricular myocytes, in which hypertrophy was induced by phenylephrine (10-5 M). In the latter model no changes in annexin V content could be observed either. In conclusion, the marked alterations in annexin V content during the maturational growth in the heart suggest a possible involvement of this protein in this process. In contrast, the absence of changes in annexin V content and localization in hypertrophied hearts compared to age matched control hearts suggests that annexin V does not play a crucial role in the maintenance of the hypertrophic phenotype of the cardiac muscle cell. This notion is supported by observations in phenylephrine-induced hypertrophied neonatal cardiomyocytes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    ISSN: 1573-4919
    Keywords: Saccharomyces cerevisiae ; NAD(P)H ; calcium ions ; cells immobilization ; oxygen consumption ; biotransformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The biochemical behaviour of four commercial strains of Saccharomyces cerevisiae was studied in the presence of calcium ions, acrylamide and bisacrylamide. Calcium ions at a concentration of 300 µM induced an increase of NAD(P)+ reduction in commercial Turkish and American strains, while in Chilean and Brazilian commercial strains, it diminished NAD(P)+ reduction. On the other hand, polyacrylamide monomers (acrylamide and bisacrylamide) induced a decrease of NAD(P)+ reduction in all strains studied in this paper. When membrane potential (ΔΨ) and oxygen consumption were measured in the presence of polyacrylamide monomers, a decrease of both was observed in all strains studied.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...