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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 45 (1989), S. 526-535 
    ISSN: 1420-9071
    Keywords: Interferon ; cytokines ; interleukins ; gene expression ; transcription ; autoimmune ; disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Specific interferon genes are transcribed at low levels in the spleen, liver, and peripheral blood leukocytes of normal individuals in the apparent absence of virus infection while other interferon genes remain unexpressed in the same tissues. In contrast, the genes of cytokines such as IL-1, IL-6 and TNF are expressed at relatively high levels in the organs of normal individuals. The level of expression of the IL-1, IL-6 and TNF genes is markedly reduced in the livers of patients with autoimmune liver disease compared to the level of expression in the liver of normal individuals, whereas the expression of interferon genes is similar in both normal and diseased liver, suggesting that a defect in the expression of specific cytokines is associated with severe liver disease.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-4927
    Keywords: mouse ; salivary protein ; lacrimal protein ; gene expression ; Spt locus ; multigene family
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The murine submandibular gland (SMG) produces a novel class of highly acidic salivary proteins encoded by one or more highly abundant mRNA transcripts. In inbred mice, these transcripts are encoded by members of a multigene family comprising approximately 8–12 homologues. Most, and probably all, of these homologues are clustered at a new locus near belted (bt) on chromosome 15, which we designateSpt (salivary protein). Although physically closely linked,Spt genes differ in their patterns of expression both in strains of mice and in their tissues. One gene,Spt-1, is expressed at high levels in the SMG of all inbred strains examined. This gene is also expressed at significant levels in the lacrimal gland. A second gene,Spt-2, appears to be present as a single copy in some strains and as two copies in others. This gene is expressed at high levels only in the SMG of those strains carrying two copies, andSpt-2 mRNA is not detectable in the SMG of strains carrying only one copy. In contrast toSpt-1, theSpt-2 gene is not expressed at detectable levels in the lacrimal gland.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1573-4927
    Keywords: mouse ; salivary protein ; lacrimal protein ; gene expression ; Spt locus ; multigene family
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The murine submandibular gland (SMG) produces a novel class of highly acidic salivary proteins encoded by one or more highly abundant mRNA transcripts. In inbred mice, these transcripts are encoded by members of a multigene family comprising approximately 8–12 homologues. Most, and probably all, of these homologues are clustered at a new locus near belted (bt) on chromosome 15, which we designateSpt (salivary protein). Although physically closely linked,Spt genes differ in their patterns of expression both in strains of mice and in their tissues. One gene,Spt-1, is expressed at high levels in the SMG of all inbred strains examined. This gene is also expressed at significant levels in the lacrimal gland. A second gene,Spt-2, appears to be present as a single copy in some strains and as two copies in others. This gene is expressed at high levels only in the SMG of those strains carrying two copies, andSpt-2 mRNA is not detectable in the SMG of strains carrying only one copy. In contrast toSpt-1, theSpt-2 gene is not expressed at detectable levels in the lacrimal gland.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1573-4919
    Keywords: complement ; factor B ; gene expression ; interferon-ψ ; interleukin-1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The serine protease complement factor B (Bf), an acute phase plasma protein, is a component of the alternative pathway of complement activation. Previous studies revealed that several cytokines including IFN-γ and IL-1 are involved in mediating acute phase Bf expression. To determine the molecular details of Bf expression we isolated, sequenced and characterized the 5′ flanking regions of the human and murine Bf genes. In both species the Bf transcriptional start site in liver was located 〈400 by 3′ to the polyadenylation site of the upstream C2 gene. This upstream intergenic region contained 〉65% nucleotide homology between species. Within this region, an IRS and three heat shock consensus elements were found in the murine sequence in an identical position to that of the human. To examine the functional details of Bf expression, a series of mouse and human Bf promoter - chloramphenicol acetyltransferase (CAT) chimeric gene constructs were transfected into mouse L or human HepG2 cells. Analysis of expression of these fusion gene constructs revealed that 1) cis-acting DNA sequences identified, at least in part, in the 3′ untranslated region of the C2 gene (within the 400 by upstream of the Bf cap site) mediate responsiveness to IL-1 and IFN-γ, 2) the responsiveness to each mediator appears to be conferred by separate upstream regions similar in position and homologous in man and mouse, and 3) the IL-1 responsive region in both species appears to have the characteristics of an enhancer element. The results of this analysis suggest a selective pressure to conserve the intergenic sequence between C2 and Bf genes and that further studies of these sequences will be useful in elucidating mechanisms controlling the acute phase response.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1573-5028
    Keywords: differential cDNA screening ; gene expression ; hybrid-select in vitro translation ; nuclear run-off transcription ; RNA blot hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A cDNA library from cultured parsley (Petroselinum crispum) cells was differentially screened using labeled run-off transcripts derived from nucleic of elicitor-treated and untreated cells. This resulted in the isolation of 18 independent cDNA families representing putative defense-related genes. All genes are rapidly and transiently activated after elicitor application, but the time courses of transcriptional activity exhibit considerable variations, indicating differences in the mechanisms of gene regulation.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Bioscience reports 9 (1989), S. 157-188 
    ISSN: 1573-4935
    Keywords: matrix hypothesis ; morphogenesis ; protodynamics ; growth control ; DNA ; genome organisation ; gene expression ; gene regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A theoretical concept is proposed, in order to explain some enigmatic aspects of cellular and molecular biology of eukaryotic organisms. Among these are the C-value paradox of DNA redundancy, the correlation of DNA content and cell size, the disruption of genes at DNA level, the “Chromosome field” data of Lima de Faria (Hereditas 93∶1, 1980), the “quantal mitosis” proposition of Holtzeret al. (Curr. Top. Dev. Biol. 7∶229 1972), the inheritance of morphological patterns, the relations of DNA and chromosome organisation to cellular structure and function, the molecular basis of speciation, etc. The basic proposition of the “Unified Matrix Hypothesis” is that the nuclear DNA has a direct morphogenic function, in addition to its coding function in protein synthesis. This additional genetic information is thought to be largely contained in the non-protein coding transcribed DNA, and in the untranscribed part of the genome.
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  • 7
    ISSN: 1573-5028
    Keywords: acyl carrier protein ; fatty acid synthesis ; gene expression ; gene fusion ; protein A ; spinach
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A synthetic gene encoding spinach acyl carrier protein I (ACP-I) was fused to a gene encoding the Fc-binding portion of staphylococcal protein A. This gene fusion, under the control of the λPR promoter, was expressed at high levels in Escherichia coli producing a 42 kDa fusion protein. This fusion protein was phosphopantethenylated in E. coli. In vitro the ACP portion of the fusion protein was able to participate in acyl ACP synthetase reactions, plant malonyl-CoA:ACP transacylase (MCT) reactions, and plant fatty acid synthetase (FAS) reactions. Inhibitory effects of high ACP concentrations on in vitro plant FAS were observed with the unfused ACP-1 but not with the fusion protein. As with unfused ACP-I, the fusion protein was a poor substrate for E. coli FAS reactions. When injected into rabbits, the fusion protein was also able to generate antiserum to spinach ACP-I.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1573-5028
    Keywords: cDNA sequence ; gene expression ; glutamine synthetase ; legume-Rhizobium symbiosis ; nitrogen metabolism ; Phaseolus vulgaris L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We report the sequence of an essentially full-length glutamine synthetase (GS) cDNA clone (pcGS-γ1) isolated from a root nodule library ofPhaseolus vulgaris L. The polypeptide encoded by this cDNA has been producedin vitro by transcription/translation and shown to co-migrate on two-dimensional gels with the previously identified major cytosolic GS polypeptide (γ) of nodules. Two previously identified GS cDNA clones, pR-2 and pR-1 (see Gebhardtet al., EMBO J 5: 1429–1435, 1986) have similarly been shown to encode the α and β cytosolic GS polypeptides respectively. An RNase protection technique has been used to analyse specifically and quantitatively the abundance of mRNA related to these three GS cDNAs and to the cDNA (pcGS-δ1) encoding the chloroplast-located GS, during nodulation. Differences in the abundances of these mRNAs at different times suggest that they are not coordinately regulated. Moreover, using this technique mRNA specifically related to pcGS-γ1 was found at high levels in nodules but not in roots or leaves. Surprisingly the expression of this gene is not nodule-specific as previously suggested, as its mRNA was also detected, but at lower levels, in stems, petioles and in green cotyledons. By comparison, mRNA related to a leghaemoglobin gene was detected only in nodules. Comparisons of the relative abundances of the pcGS-γ1 mRNA and the γ polypeptide in different organs and at different stages during nodulation, suggest that the appearance of the γ polypeptide is largely under transcriptional control.
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  • 9
    ISSN: 1573-5028
    Keywords: antisense RNA ; β-glucuronidase ; tobacco ; transgenic plants ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Antisense RNA was used to specifically inhibit the expression of a GUS gene introduced in a transgenic plant. A tobacco transformant containing a single intact copy of the GUS gene and showing relatively high constitutive levels of GUS activity (GUS+) was re-transformed with an Agrobacterium Ti-derived binary vector containing an antisense version of this reporter gene. The sense and antisense GUS genes were each under the regulation of the CaMV 35S promoter. Re-transformed plants contained 1–5 copies of the antisense construct and all showed a greater than 90% reduction in GUS activity relative to the original GUS+ plant. This reduction in GUS activity correlated closely with the levels of GUS enzyme and steady state GUS mRNA observed in these plants. The relatively low levels of sense and antisense GUS transcripts found in the re-transformed plants may indicate a rapid degradation of the RNA:RNA duplex in the cell.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1573-5028
    Keywords: deformation factor ; gene expression ; pea ; Rhizobium leguminosarum ; root hairs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The mRNA population in pea root hairs was characterized by means of in vitro translation of total root hair RNA followed by 2-dimensional gel electrophoresis of the translation products. Root hairs contain several mRNAs not detectable in total RNA preparations from roots. Most of these root hair-specific mRNAs occur in elongating root hairs at higher levels than in mature root hairs. The expression of some genes in pea root hairs is typically affected by inoculation with Rhizobium leguminosarum. One gene, encoding RH-42, is specifically induced while the expression of another gene, encoding RH-44, is markedly enhanced. Using R. leguminosarum mutants it was shown that the nodC gene is required for the induction and enhancement of expression of the RH-42 and RH-44 genes, respectively, while the Rhizobium chromosomal gene pss1, involved in exopolysaccharide synthesis, is not essential. After induction of the nod genes with apigenin the bacteria excrete into the culture medium a factor that causes root hair deformation. This deformation factor stimulates the expression of the RH-44 gene but does not induce the expression of the gene encoding RH-42.
    Type of Medium: Electronic Resource
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 12 (1989), S. 295-299 
    ISSN: 1573-5028
    Keywords: gene expression ; multiple transcripts ; phytochrome ; Pisum sativum ; red/far-red reversible effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The reversible effect of red and far-red light on the level of two RNA transcripts of the single-copy phytochrome gene in pea was investigated using the primer extension assay. In dark-grown seedlings, a brief irradiation with red light markedly reduced the level of one of the phytochrome transcripts, RNA1. This red light effect was reversed by subsequent irradiation with far-red light. The other phytochrome transcript, RNA2, was only slightly influenced by light. In light-grown seedlings, a brief irradiation with far-red light increased the content of both RNA1 and RNA2 when the seedlings were transferred from light to darkness. This far-red light effect was reversible by subsequent red light irradiation.
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  • 12
    ISSN: 1573-5028
    Keywords: C4 photosynthesis ; gene structure ; gene expression ; genetic variation ; silent substitution ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have determined the structure of the maize (Zea mays L. subsp.mays line B73) nuclear gene encoding the phosphoenolpyruvate (PEP) carboxylase isozyme involved in C4 photosynthesis. The gene is 5.3 kb long and has ten exons that range in size from 85 to 999 bp. The nine introns vary from 97 to 872 bp. The sequence of 663 bp of 5′-flanking and 205 bp of 3′-flanking DNA is reported along with the entire gene sequence. Several short repetitive sequences were found in the 5′-flanking DNA that have characteristics similar to elements important in the light regulation of pea genes encoding the small subunit of ribulose 1,5-bisphosphate carboxylase. In addition, some 5′-flanking sequence similarities were found in a comparison with other light-regulated genes from maize and wheat. The level of DNA sequence variation among different PEP carboxylase alleles is similar to the allelic variation observed for several other maize nuclear genes. The data suggest modern maize variaties have retained much of the genetic variation present in their ancestral forms. Finally, accumulation of transcripts encoding the PEP carboxylase isozyme involved in C4 photosynthesis is quite high in several structures besides leaves, including inner leaf sheaths, tassels and husks. This indicates that expression of this gene is not leaf-specific and may not necessarily be coupled to the development of Kranz anatomy.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 12 (1989), S. 673-682 
    ISSN: 1573-5028
    Keywords: amylase inhibitor ; barley ; cDNA sequence ; gene expression ; hormonal regulation ; protease inhibitor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have cloned and sequenced a full-length cDNA from barley (Hordeum vulgare L.) seeds encoding the bifunctional α-amylase/subtilisin inhibitor (BASI). The nucleotide sequence predicts an open reading frame coding for a protein of 203 amino acids. The first 22 amino acids exhibit the sequence characteristic of a signal peptide, as found in several other plant protease inhibitors. Northern blot hybridization experiments indicate that BASI mRNA accumulation is strictly tissue-specific and is developmentally programmed. BASI mRNA transcripts were only identified in 1) developing starchy endosperm tissue from 14 days after flowering and 2) aleurone tissue of germinating seeds. In this latter tissue, BASI mRNA accumulation is enhanced by abscisic acid and abolished by gibberellic acid. Expression of BASI mRNA was also studied in the lys 3a high-lysine barley mutants Risø No. 1508 and Piggy. These high-lysine barleys show 2–4-fold higher levels as well as prolonged accumulation of BASI mRNA compared to the normal motherline Bomi. This correlates with the increased deposition of BASI protein in lys 3a barley mutants. Genomic blot analysis of barley DNA suggests that there are one or two BASI structural genes per haploid genome. Possible roles of BASI as part of a defence mechanism against precocious germination and pathogens are discussed.
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  • 14
    ISSN: 1573-5028
    Keywords: cadmium ; Datura innoxia ; gene expression ; heat shock ; tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of Cd on gene expression in suspension cultures of twoDatura innoxia cell lines with differing Cd tolerance was studied.In vivo labeling experiments using [3H] leucine showed that Cd induced the synthesis of a similar range of proteins in both cell lines at a concentration which will kill the sensitive but not the tolerant cells. Corresponding changes in levels of translatable mRNA were also observed. The induction of the synthesis of proteins by Cd was transient since Cd-tolerant cells growing continuously in 250 μM CdCl2 contained a similar set ofin vitro translation products to cells growing in the absence of Cd. Although Cd had a similar effect on gene expression in both cell lines, Cd-tolerant cells possess two abundant mRNAs which are constitutively produced. These mRNAs encode proteins of low molecular weight (about 11 kDa) and are either absent or present at a low level in Cd-sensitive cells. The functions of these proteins are not known but they may be involved in the tolerance mechanism. Two-dimensional gel electrophoresis ofin vitro translation products showed that many of the Cd-induced proteins are also induced by heat shock. A 42°C heat shock resulted in agreater range and more intense induction of translatable mRNAs than 4 h exposure to 250 μM CdCl2. However a subset of mRNAs were induced specifically by Cd while other mRNAs were heat shock-specific. There was no difference in the ability of the two cell lines to tolerate heat shock. This was also reflected by the same pattern of major proteins induced by heat shock in the two cell lines.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 12 (1989), S. 667-672 
    ISSN: 1573-5028
    Keywords: ferredoxin ; gene expression ; heterocyst ; Anabaena 7120 ; Escherichia coli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genes for ferredoxin from heterocysts (fdx H) and vegetative cells (pet F) of Anabaena sp. strain 7120 were subcloned into plasmid pUC 18/19. Both genes were expressed in Escherichia coli at high levels (≈10% of total protein). Pet F could be expressed from its own promoter. The ferredoxins were correctly assembled to the holoprotein. Heterocyst ferredoxin was purified from E. coli extracts on a large scale. Its biochemical and biophysical properties were identical to those of the authentic ferredoxin, isolated from Anabaena heterocysts.
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  • 16
    ISSN: 1573-5028
    Keywords: cDNA ; gene expression ; hydroxypyruvate reductase ; light regulation ; peroxisomal enzyme
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A full-length cDNA encoding NADH-dependent hydroxypyruvate reductase (HPR), a photorespiratory enzyme localized in leaf peroxisomes, was isolated from a λgt11 cDNA library made by reverse transcription of poly(A)+ RNA from cucumber cotyledons. In vitro transcription and translation of this clone yielded a major polypeptide which was identical in size, 43 kDA, to the product of in vitro translation of cotyledonary poly(A)+ RNA and subsequent immunoprecipitation with HPR antiserum. Escherichia coli cultures transformed with a plasmid construct containing the cDNA insert were induced to express HPR enzyme activity. RNA blot analysis showed that HPR transcript levels rise significantly in the first eight days of light-grown seedling development. This closely resembles the pattern seen for HPR-specific translatable mRNA. DNA blot analysis indicated that a single HPR gene is likely present per haploid genome. Nucleotide sequence analysis revealed an open reading frame of 1146 bases which encodes a polypeptide with a calculated molecular weight of 41.7 kDa. The derived amino acid sequence from this open reading frame is 26% identical and 50% similar to the amino acid sequence of the E. coli enzyme phosphoglycerate dehydrogenase, which catalyzes a similar reaction and functions in a related pathway. Statistical analyses show that this similarity is significant (z〉10). The derived amino acid sequence for HPR also contains the characteristics of an NAD-binding domain.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Bulletin of experimental biology and medicine 108 (1989), S. 999-1001 
    ISSN: 1573-8221
    Keywords: brain ; gene expression ; mRNA ; transplantable hepatomas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular neurobiology 9 (1989), S. 281-294 
    ISSN: 1573-6830
    Keywords: cholecystokinin ; mammillary region ; development ; gene expression ; hybridization histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. The ontogeny and adult distribution of neurons containing cholecystokinin (CCK) mRNA in the premammillary and mammillary nuclei and supramammillary region of the rat brain were studied using hybridization histochemistry. 2. The earliest detection of CCK mRNA in the mammillary region was on E14, followed by a marked increase in transcript levels during the next 4 days, a time during which neurons in this region still divide. During the first 2 weeks of life, few changes in the levels of CCK transcripts were seen, and an adult-like pattern of expression was seen on the twenty-first day of life. 3. Low levels of transcripts were present in numerous neurons located in all divisions of the medial nucleus and in the posterior nucleus known to project ipsilaterally to the anteroventral and anteromedial thalamic nuclei. In contrast, none of the neurons in the lateral nucleus (projecting bilaterally to the anterodorsal thalamic nucleus) had detectable transcripts. 4. Many neurons in the supramammillary nucleus had low, moderate, or high levels of transcripts. Some nearby nuclei (such as the dorsal premammillary nucleus) had smaller numbers of neurons with low levels of CCK mRNA, whereas others (such as the ventral premammillary nucleus) had none.
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  • 19
    ISSN: 1572-994X
    Keywords: BAL31 nuclease ; CAT assay ; gene expression ; HTLV-I ; R region ; 5′ untranslated sequence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We previously demonstrated the activity of the R fragment in the long terminal repeat of human T-cell leukemia virus type I for elevation of the level of gene expression. In this study, the fragment was deleted with BAL31 nuclease to determine its functional domain. Series of the shortened R fragments were linked to the simian virus 40 promoter unit, which regulated expression of a reporter gene. Examination with the R fragments deleted from the 5′ and 3′ ends showed that borders of the functional domain were mapped within nucleotide positions 458 to 473 for the 5′ end and nucleotide positions 559 to 594 for the 3′ end, respectively. Thus we conclude that a 136-base-pair fragment corresponding to the second half of the R region was sufficient to allow elevation of the level of gene expression.
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  • 20
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 41 (1989), S. 179-188 
    ISSN: 0730-2312
    Keywords: protein kinase C ; TPA ; cell transformation ; gene expression ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: We have used a previously described retroviral expression vector pMV7-PKCβ1 to develop derivatives of two rat liver epithelial cell lines, K16 and K22, that stably express about tenfold-higher PKC activity than control cells. Despite these high levels of PKC, these cells did not exhibit gross morphologic changes, anchorage-independent growth, or tumorigenicity. K16PKC-4 and K22PKC-2, two lines with the highest PKC enzyme activity, were studied further in terms of several responses to the phorbol ester tumor promoter TPA. When treated with 100 ng/ml of TPA, the control K16MV7 and K22MV7 cells displayed a slight change in morphology, whereas the K16PKC-4 and K22PKC-2 cells displayed a marked change in morphology. Northern blot analyses demonstrated that TPA induced increased levels of fos, myc, phorbin, and ODC RNAs in control K16MV7 and K22MV7 cells, with maximum induction occurring at about 0.5, 1, 8, and 8 h, respectively. In K16PKC-4 and K22PKC-2 cells, TPA induction of phorbin and ODC RNAs was markedly enhanced, but this was not the case for myc and fos RNAs. In addition, the levels of myc RNA were constitutively higher in both K16PKC-4 and K22PKC-2 cells than in the control cells. Taken together, these results provide direct evidence that PKC plays a critical role in modulating the expression of myc, phorbin, and ODC RNAs. On the other hand, overexpression of PKCβ1 is not itself sufficient to cause cell transformation.
    Additional Material: 3 Ill.
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  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 44 (1988), S. 910-919 
    ISSN: 1420-9071
    Keywords: Heart embryology ; developmental biology ; differentiation ; morphogenesis ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The subject of heart development has attracted the interest of many embryologists over the last two centuries. As a result, the main morphologic features of the developmental anatomy of the heart are already well established. Although there are still some controversial points, and there is probably much descriptive work yet to be done, emphasis is currently being placed on developmental mechanisms rather than simply on descriptive facts. The availability of new techniques and the overall advances in biological research are placing heart embryology in a new perspective. Today, we do not simply ask whether one or another embryonic structure arises further right or further left; instead, we are studying how cells, tissues, and their microenvironment interrelate at the several levels of biological organization (from the gene upwards) so as to give rise to a mature organ with a distinct shape and well-established functions. This paper attempts to review some of the basic aspects of the developmental anatomy of the heart. Descriptive embryology is used here as a tool. Emphasis is placed on developmental mechanisms, and on the present knowledge of how these mechanisms are related to the structural development of the heart.
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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 44 (1988), S. 930-936 
    ISSN: 1420-9071
    Keywords: Cardiac development ; embryogenesis ; gene expression ; complementary DNA ; molecular methodologies ; myocardial contractility ; myosin ; atrial natriuretic factor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cardiac development involves a complex integration of subcellular processes into multicellular and, finally, whole organ effects. Until recently it has been difficult to investigate the genetic control of this organ level differentiation of the heart. The proliferation of molecular biology methodologies has provided mechanisms to directly investigate the control of these processes. This article focuses on molecular lines of research on two key areas in cardiac development: the regulation of expression of sarcomeric contractile and regulatory proteins, and atrial natriuretic factor. Molecular approaches are described which have allowed investigators to begin to determine the tissue and stage-specific expression of genes, to locate those genes in the genome, determine their sequences, and to directly investigate the mechanisms controlling their expression.
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  • 23
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 44 (1988), S. 52-55 
    ISSN: 1420-9071
    Keywords: Human sperm ; human protamine ; protamine 1 ; protamine 2 ; protamine 3 ; infertility ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Protamines were extracted from the sperm of fertile and infertile human males and the relative proportion of protamines 1, 2, and 3 were determined by scanning microdensitometry following electrophoresis of total protamine in polyacrylamide gels. The proportion of the three protamines was found to be similar in sperm obtained from different normal males. The distribution of protamines in sperm obtained from a select group of infertile males producing an elevated level of large sperm heads, in contrast, was different from that of the fertile males.
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  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Molecular and cellular biochemistry 84 (1988), S. 3-15 
    ISSN: 1573-4919
    Keywords: prostate ; androgens ; gene expression ; in situ hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary After castration, the rat dorsolateral prostate M-40 mRNA initially decreased then rebounded to precastrated levels. The cellular site of M-40 expression and its renewed expression after castration was defined by in situ hybridization histochemistry. In situ hybridization with either a 32P-labeled or biotin-labeled M-40 cDNA probe demonstrated that M-40 mRNA levels were higher in the lateral than dorsal prostate. A second androgen regulated gene, RWB, also was highly expressed in the lateral prostate. The biotinylated cDNA probes provided microscopic resolution of the expressing cells, revealing two distinct morphologies of lateral epithelium which expressed both the M-40 and RWB mRNA. These morphologies appeared in ducts which contained either epithelial cell sheets that were highly convoluted or thinner epithelial cells with a minimal degree of convolution. The RWB mRNA decreased in both cell populations in response to androgen withdrawal. The decline and reappearance of M-40 mRNA also appeared in both epithelial cell types. These data demonstrated that after castration the M-40 mRNA initially decreased as expected for an androgen sensitive gene and then progressed to a fully inducible state. The mechanism of this progression remains to be elucidated.
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  • 25
    ISSN: 1573-4927
    Keywords: cat hemoglobins ; polymorphism ; DNA ; restriction endonuclease ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The molecular basis for the genetic control of variable proportions of the two cat hemoglobins Hb A(α2β 2 A ) and Hb B (α2β 2 B ) was investigated. Ratios of Hb A/Hb B vary between 50/50 and 90/10 among members of the mongrel cat population, with clusters around 50, 35, and 10% Hb B. Genomic DNA from cats of 50/50, 70/30, and 90/10 phenotypes were cut by restriction endonucleasesHindIII,EcoRI,BamHI,Bg1II,and Pst1 and hybridized to a fragment of the human β-globin gene. The results of the Southern blots suggested a pattern of homozygote, heterozygote, homozygote for the respective cat phenotypes, 50/50, 70/30, and 90/10. Therefore, the cat hemoglobin polymorphism seems to result from the possible combinations of an allelic gene pair.
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  • 26
    ISSN: 1573-5028
    Keywords: barley ; chymotrypsin inhibitor ; gene expression ; endosperm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Full-length cDNA clones for barley chymotrypsin inhibitor 1 (CI-1) have been isolated from an endosperm-specific cDNA library. Hybridization and nucleotide sequence analyses indicate that these cDNAs represent two distinct types of CI-1 mRNA which we have called CI-1A and CI-1B. Both mRNAs encode polypeptides of 83 residues (M r=8790 and 8960) which differ at eleven positions. The full-length cDNA sequences do not predict N-terminal signal peptide extensions indicating that CI-1 is synthesized in the mature form in contrast to the homologous proteinase inhibitors of tomato and potato. Northern hybridization experiments show that the CI-1 genes are under strict developmental and organ-specific control. CI-1 transcripts were first detected in the developing barley endosperm between 12 and 14 days after anthesis but no CI-1-related sequences were detected in the RNA preparations from shoots, leaves or roots. The expression of CI-1 was also studied in the high-lysine barley mutants Hiproly, Risø 56 and Risø 1508. Approximately 15-fold (Hiproly) and 4-fold (Risø 56 and 1508) higher levels of CI-1 mRNA were detected in the mutant endosperms compared to normal barley. These results correlate well with the increased deposition of CI-1 in the high-lysine lines and show that the differential expression is controlled mainly at the level of transcription or stability of the mRNA. Using Southern-blots of barley DNA we estimate that there are three copies of CI-1 per haploid genome in both normal and mutant barley lines.
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  • 27
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    Plant molecular biology 11 (1988), S. 641-649 
    ISSN: 1573-5028
    Keywords: codon usage ; gene expression ; histone H3 gene ; Medicago sativa ; somatic embryos
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A histone H3 gene was isolated from a dicotyledonous plant, alfalfa (Medicago sativa). The sequence analysis of this gene revealed no obvious GC preference in its codon usage. Apart from containing most of the typical consensus sequences found in both animal and plant histone genes, the alfalfa H3 gene exhibits distinct structural features such as (1) the unusual location of two GATCC motifs in its 5′ flanking sequence, (2) the existence of a CGCGGATC on the nonsense strand at position −232, (3) the existence of a long palindromic structure, and (4) several polyadenylation signal-like sequences in the 3′ flanking region. There are about 160 copies of histone H3 gene in alfalfa tetraploid genome. Using the alfalfa H3 gene as a probe to study the pattern of histone H3 transcripts in the alfalfa, we found that the H3 RNAs are undetectable in leaves, more in stems than in roots, and highest in somatic embryos. Moreover, the RNA products of H3 genes in all alfalfa tissues tested show unusually long nontranslated region compared to those of animal histone genes. An additional high molecular weight species of H3 transcript was detected only in somatic embryos.
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  • 28
    ISSN: 1573-5028
    Keywords: Agrobacterium ; gene expression ; legumin (Pisum) ; Nicotiana ; seed storage protein ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A 3.4-kilobase genomic DNA fragment from Pisum sativum L. containing the LegA gene, which encodes a major legumin storage protein, was transferred to Nicotiana plumbaginifolia using an Agrobacterium tumefaciens strain containing the Bin 19 binary vector system. Northern hybridisation analysis of legA-transformed plants demonstrated that legumin-specific RNA was present in developing seeds but not in developing leaves. Legumin protein was immunologically detected in the mature seeds of legA-transformed plants, and was present as the correct-size protein composed of disulphide-bonded polypeptides. It is concluded that the transferred pea genomic fragment contains all the information necessary for seed-specific expression of the legA gene, and for correct processing of the primary transcript and the precursor legumin protein.
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  • 29
    ISSN: 1573-5028
    Keywords: potato ; patatin ; proteinase inhibitor ; cloning ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Tuberization in potato is a complex developmental process involving the expression of a specific set of genes leading to the synthesis of tuber proteins. We here report the cloning and analysis of mRNAs encoding tuber proteins. From a potato tuber cDNA library four different recombinants were isolated which hybridized predominantly with tuber mRNAs. Northern blot hybridization experiments showed that three of them, pPATB2, p303 and p340, can be regarded as tuber-specific while the fourth, p322, hybridizes to tuber and stem mRNA. Hybrid-selected in vitro translation and nucleotide sequence analysis indicate that pPATB2 and p303 represent patatin and the proteinase inhibitor II mRNA respectively. Recombinant p322 represents an mRNA encoding a polypeptide having homology with the soybean Bowman-Birk proteinase inhibitor while p340 represents an mRNA encoding a polypeptide showing homology with the winged bean Kunitz trypsin inhibitor. In total, these four polypeptides constitute approximately 50% of the soluble tuber protein. Using Southern blot analysis of potato DNA we estimate that these mRNAs are encoded by small multigene families.
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  • 30
    ISSN: 1573-5028
    Keywords: cDNA sequence ; chloroplast protein import ; gene expression ; glutamine synthetase ; nitrogen metabolism ; Phaseolus vulgaris L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Work using a full-length cDNA clone has revealed that the plastid-located glutamine synthetase (GS) of Phaseolus vulgaris is encoded by a single nuclear gene. Nucleotide sequencing has shown that this cDNA is more closely related to a cDNA encoding the plastidic GS of Pisum sativum than to cDNAs encoding three different cytosolic GS subunits of P. vulgaris. The plastid GS subunits are initially synthesized as higher M r (47000) precursors containing an N-terminal presequence of about 50 amino acids which is structurally similar to the presequences of other nuclear-encoded chloroplast proteins. The precursor has been synthesized in vitro and is imported by isolated pea chloroplasts and processed to two polypeptides of the same size as native P. vulgaris chloroplast GS subunits (M r 42000). Experiments with fusion proteins show that the N-terminal 68 amino acids of this precursor allow the cytosolic GS subunit β also to be imported and processed by isolated chloroplasts. Polyadenylated mRNA specifically related to the plastidic GS gene is most highly abundant in chloroplast-containing organs (leaves and stems) but is also detectable in roots and nodules.
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  • 31
    ISSN: 1573-5028
    Keywords: glyphosate ; herbicide ; 5-enolpyruvylshikimic acid 3-phosphate (EPSP) synthase ; enzyme overproduction ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cell cultures of Corydalis sempervirens adapted to growth in the presence of 5 mM glyphosate [N-(phosphonomethyl)glycine] display a 30- to 40-fold increase in the cellular content of 5-enolpyruvylshikimic acid 3-phosphate (EPSP) synthase, the target enzyme of the herbicide. Translatable mRNA activity as well as transcript levels for EPSP synthase were increased 8-to 12-fold in the adapted (glyphosate-tolerant) as compared to the non-adapted (glyphosate-sensitive) cultures. Northern blot analysis revealed a single 1.8 kb transcript after hybridization with an oligonucleotide probe deduced from the N-terminal amino acid sequence of the enzyme. No significant differences in the relative abundance of EPSP synthase-specific DNA sequences could be detected, however, in Southern and dot blot analyses of restricted DNA isolated from the two cultures. We conclude that the overproduction of EPSP synthase in glyphosate-tolerant C. sempervirens cells is not based on the amplification of the corresponding gene.
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  • 32
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    Plant molecular biology 11 (1988), S. 495-506 
    ISSN: 1573-5028
    Keywords: abscisic acid ; barley aleurone layers ; cDNA cloning ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Abscisic acid (ABA) inhibits the gibberellic acid induced synthesis of α-amylase in barley aleurone layers, yet ABA itself induces more than a dozen polypeptides (Lin & Ho, Plant Physiol 82: 289–297, 1986). As part of our effort to elucidate the molecular action of ABA in barley aleurone layers, we have isolated and characterized an ABA-induced cDNA clone, pHV A1. This cDNA clone hybridizes to an RNA species of approximately 1.1 kb from ABA-treated barley aleurone layers. The level of this mRNA is tripled within 40 minutes after ABA treatment, reaches a peak at 8–12 h, and is present up to 48 h. The induction of this mRNA responds to concentrations of ABA as low as 10-9 M, but higher ABA concentrations induce higher expression of this mRNA. The products of hybrid-select translation and in vitro transcription/translation with pHV A1 comigrate on SDS gel as a 27 kDa polypeptide. However, the sequence of pHV A1 indicates that it has an open reading frame encoding a 22 kDa protein. This size discrepancy is probably due to the high content of the basic amino acid, lysine. This notion has been confirmed by two-dimensional gel electrophoresis showing that this polypeptide is one of the most basic proteins in ABA-treated barley aleurone layers. The deduced amino acid sequence of pHV A1 contains nine imperfect repeats 11 amino acids long which share homology with cotton Lea 7 protein (Baker, Steele & Dure, Plant Mol Biol, in press). The identity and function of the encoded product of pHV A1 is under investigation.
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  • 33
    ISSN: 1573-0778
    Keywords: CG suppression ; DNA methylation ; gene expression ; MHC ; mutation hot spots
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract DNA methylation of human class II genes of the Major Histocompatibility Complex (MHC) was correlated with gene expression and methyl-related CG → TG and CG → CA changes. It was found that cytosine methylation of the CG dinucleotides of MHC class II genes should be involved in generating a fraction of nucleotide polymorphism, rather than in controlling transcription.
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  • 34
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    Photosynthesis research 18 (1988), S. 7-31 
    ISSN: 1573-5079
    Keywords: Nicotiana ; chloroplast genome ; photosynthesis ; NADH dehydrogenase ; protein structure ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In order to understand more fully chloroplast genetic systems, we have determined the complete nucleotide sequence (155, 844 bp) of tobacco (Nicotiana tabacum var. Bright Yellow 4) chloroplast DNA. It contains two copies of an identical 25,339 bp inverted repeat, which are separated by 86, 684 bp and 18,482 bp single-copy regions. The genes for 4 different rRNAs, 30 different tRNAs, 44 different proteins and 9 other predicted protein-coding genes have been located. Fifteen different genes contain introns. Twenty-two genes for components of the photosynthetic apparatus have so far been identified. Most of the genes (except the gene for the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase) code for thylakoid membrane proteins. Twenty of them are located in the large single-copy region and one gene for a 9-kd polypeptide of photosystem I is located in the small single-copy region. The gene for the 32-kd protein of photosystem II as well as the gene for the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase have strong promoters and are transcribed monocistronically while the other genes are transcribed polycistronically. We have found that the predicted amino acid sequences of six DNA sequences resemble those of components of the respiratory-chain NADH dehydrogenase from human mitochondria. As these six sequences are highly transcribed in tobacco chloroplasts, they are probably genes for components of a chloroplast NADH dehydrogenase. These observations suggest the existence of a respiratory-chain in the chloroplast of higher plants.
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  • 35
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    Photosynthesis research 19 (1988), S. 63-71 
    ISSN: 1573-5079
    Keywords: CO2 fixation ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract From studies conducted in both our laboratory and by Gibson, Tabita and colleagues, as well as drawing on the recent studies with Alcaligenes eutrophus, we describe two genetic regions which have been identified on the chromosome of Rhodobacter sphaeroides which code for a number of enzymes involved in CO2 fixation. One region was found to contain the genes coding for fructose 1,6-bisphosphatase (fbpA), phosphoribulokinase (prkA), a 37 kDa polypeptide (cfxA), and form I ribulose 1,5-bisphosphate carboxylase/oxygenase (rbcL, S). These genes appear to be expressed in the same transcriptional direction and are tandomly arranged. A second, apparently unlinked region of the chromosome contains a duplicate (with respect to functionality of gene products) but not identical set of these same four genes. Although the gene order in both regions is apparently identical, there is approximately 4 kb of DNA separating the 3′-end of prkB and the beginning of cfxB. The specific genetic organizations and proposed roles of these two genetic regions are discussed.
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  • 36
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    Photosynthesis research 19 (1988), S. 129-152 
    ISSN: 1573-5079
    Keywords: chloroplast biogenesis ; gene expression ; ribosomes ; transcription ; translation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Isolated chloroplasts show substantial rates of protein synthesis when illuminated. This ‘in organello’ protein synthesis system has been advantageously utilised to elucidate the coding capacity of chloroplast and the regulation of chloroplast genes. The system is also being used recently to transcribe and translate homologous and heterologous templates. In this mini-review, we attempt to critically ecaluate the available literature and present the current and the prospective lines of research.
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  • 37
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    Photosynthesis research 18 (1988), S. 205-222 
    ISSN: 1573-5079
    Keywords: ATP synthase ; chloroplast ; evolution ; gene expression ; operon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three CF1 and three CF0 subunits of the chloroplast H+-ATP synthase are encoded on the chloroplast genome. The chloroplast atp genes are organized as two operons in plants but not in the green alga, Chlamydomonas reinhardtii. The atpBE or β operon shows a relatively simple organisation and transcription pattern, while the atpIHFA or α operon is transcribed into a large variety of mRNAs. The atp genes are related to those of cyanobacteria and, more distantly, to those of non-photosynthetic bacteria such as E. coli, suggesting a common origin of most F1F0 ATP synthase subunits. Both the chloroplast and cyanobacterial ATP synthases have four F0 subunits, not three as in the E. coli complex. The proton pore of the CF0 is proposed to be formed by the interaction of subunits III and IV.
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  • 38
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    Photosynthesis research 17 (1988), S. 145-157 
    ISSN: 1573-5079
    Keywords: Carbon fixation ; enzyme assembly ; gene expression ; recombinant DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The synthesis in Escherichia coli of both the large and small subunits of cereal ribulose bisphosphate carboxylase/oxygenase has been obtained using expression plasmids and bacteriophages. The level and order of synthesis of the large and small subunits were regulated using different promoters, resulting in different subunit pool sizes and ratios that could be controlled in attempts to optimize the conditions for assembly. Neither assembly nor enzyme activity were observed for the higher plant enzyme. In contrast, cyanobacterial large and small subunits can assemble to give an active holoenzyme in Escherichia coli. By the use of deletion plasmids, followed by infection with appropriate phages, it can be demonstrated that the small subunit is essential for catalysis. However, the small subunit is not required for the assembly of a large subunit octomer core in the case of the Synechococcus enzyme; self-assembly of the octomer will occur in an rbcS deletion strain. The cyanobacterial small subunits can be replaced by wheat small subunits to give an active enzyme in Escherichia coli. The hybrid cyanobacterial large/wheat small subunit enzyme has only about 10% of the level of activity of the wild-type enzyme, reflecting the incomplete saturation of the small subunit binding sites on the large subunit octomer, and possibly a mismatch in the subunit interactions of those small subunits that do bind, giving rise to a lower rate of turnover at the active sites.
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  • 39
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    Journal of bioenergetics and biomembranes 20 (1988), S. 19-39 
    ISSN: 1573-6881
    Keywords: E. coli unc operon ; H+-ATPase ; subunit stoichiometry ; gene expression ; codon usage ; translational initiation ; Shine-Dalgarno sequence ; recombinant DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract Theunc (or atp) operon ofEscherichia coli comprises eight genes encoding the known subunits of the proton-translocating ATP synthase (H+-ATPase) plus a ninth gene (uncI) of unknown function. The subunit stoichiometry of the H+-ATPase (α 3β3γ1δ1ε1a1b2c10–15) requires that the respectiveunc genes be expressed at different rates. This review discusses the experimental methods applied to determining how differential synthesis is achieved, and evaluates the results obtained. It has been found that the primary level of control is translational initiation. The translational efficiencies of theunc genes are determined by primary and secondary mRNA structures within their respective translational initiation regions. The respective rates of translation are matched to the subunit requirements of H+-ATPase assembly. Finally, points of uncertainty remain and experimental strategies which will be important in future work are discussed.
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  • 40
    ISSN: 1573-7241
    Keywords: Atrial natriuretic peptide ; cardiac myocytes ; gene expression ; hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Primary cultures of neonatal cardiocytes expreses the gene for atrial natriuretic peptide (ANP). In general the levels of expression follow the rank order: atrial 〉 ventricular ≫ nonmyocardial cells. Following the initial dispersion cardlocytes require 48 to 72 hours before ANP seeretion and ANP mRNA accumulation approach a new steadystate level. In situ hybridization analysis indicates that ANP gene expression is concentrated in a subpopulation of cardiocytes in both the atrial and the ventricular cell cultures. These findings suggest that these primary cultures may be of value in defining the faciors governing the expression of the ANP gene in the cardiac cell.
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  • 41
    ISSN: 1573-5079
    Keywords: Crassulacean acid metabolism ; gene expression ; Mesembryanthemum crystallinum ; mRNA levels ; soil salinity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mesembryanthemum crystallinum responds to high salinity in the soil by shifting the mode of carbon assimilation from the C3 mode to Crassulacean acid metabolism (CAM). Several enzymes of carbon metabolism have increased apparent activities in the CAM mode, including phosphoenolpyruvate carboxylase (PEPcase) and pyruvate orthophosphate dikinase (PPDK). We have identified cDNA clones for PEPcase and PPDK by immunological screening of a cDNA library constructed in the protein expression vector lambda gt11. The clones were characterized by immunoblotting and RNA blotting techniques. RNA blotting showed that during CAM induction the steady-state level of mRNAs for both PEP case and PPDK increased.
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  • 42
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    Photosynthesis research 19 (1988), S. 39-61 
    ISSN: 1573-5079
    Keywords: Bacteriochlorophyll-protein complex ; gene expression ; light-harvesting complex ; reaction center ; Rhodospirillaceae ; transcriptional control ; translational control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The puf operon of the purple nonsulfur photosynthetic bacterium, Rhodobacter sphaeroides, contains structural gene information for at least two functionally distinct bacteriochlorophyll-protein complexes (light harvesting and reaction center) which are present in a fixed ratio within the photosynthetic intracytoplasmic membrane. Two proximal genes (pufBA) specify subunits of a long wavelength absorbing (i.e., 875 nm) light harvesting complex which are present in the photosynthetic membrane in ≃15 fold excess relative to the reaction center subunits which are encoded by the pufLM genes. This review summarizes recent studies aimed at determining how expression of the R. sphaeroides puf operon region relates to the ratio of individual bacteriochlorophyll-protein complexes found within the photosynthetic membrane. These experiments indicate that puf operon expression may be regulated at the transcriptional, post-transcriptional, translation and post-translational levels. In addition, this review discusses the possible role(s) of newly identified loci upstream of pufB which may be involved in regulating either synthesis or assembly of individual bacteriochrlorophyll-protein complexes as well as the pufX gene, the most distal genetic element within the puf operon whose function is still unknown.
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  • 43
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    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 37 (1988), S. 243-253 
    ISSN: 0730-2312
    Keywords: hepatocyte differentiation ; gene expression ; hormonal control ; glucocorticoids ; insulin ; cyclic AMP ; tyrosine aminotransferase ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Cloned cDNAs were used in hybridization analyses to assess hormonal responsiveness of two similarly regulated genes in livers of late-term fetal rats. Transcription of the tyrosine aminotransferase gene and of gene 33 (Lee et al.: J Biol Chem 260:16433-16438, 1985) is enhanced by glucocorticoids and by each of the usually antagonistic hormonal agents, insulin and cAMP, in adult liver, and that of both genes is developmentally activated at or just prior to birth. The mRNA of gene 33 was found to be significantly increased by each of the hormonal regulators in livers of fetuses treated in utero. Expression of the nearly silent aminotransferase gene in fetal liver was appreciably increased by cAMP but was refractory to control by either glucocorticoids or insulin; capacity of this gene to respond to insulin was not realized until several days postpartum. The data indicate specificity in the developmental acquisition of the capacity of individual genes to respond to hormonal regulators.
    Additional Material: 9 Ill.
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  • 44
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    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 38 (1988), S. 205-212 
    ISSN: 0730-2312
    Keywords: cytokines ; gene expression ; retroviral promoters ; antitumoral activities ; phenotypical reversion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The potential mechanisms of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha action on tumor cells have been investigated in a model of mouse fibroblasts transformed by distinct retroviral vectors carrying the v-mos, c-myc, and v-Ha-ras oncogene, respectively. Treatment with both cytokines not only caused growth inhibition of v-mos- and c-myc-transformants, but also a reversion of transformation-induced suppression of major histocompatibility complex (MHC) class I antigen expression in all transformed cell lines. The phenotypical reversion of transformants was preceded by a selective modulation of LTR-controlled oncogene expression. TNF-alpha primarily affected stability of oncogene-specific RNAs without influencing the activity of retroviral promoters. In contrast, IFN-gamma was effective at the transcriptional level, apparently due to inhibition of LTR activity as revealed from reduced CAT activity in IFN-gamma-treated LTR-CAT transformants. This IFN-gamma-mediated down-regulation of retroviral promoter activity seemed to be selective for Moloney-virus-derived promoters, since the activity of other viral and cellular promoters was not suppressed by IFN-gamma.
    Additional Material: 1 Ill.
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  • 45
    ISSN: 0730-2312
    Keywords: ADP-ribosyl transferase ; cell proliferation ; gene expression ; protein kinase C ; c-myc expression ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Human α or β interferons inhibit the proliferation of Daudi Burkitt lymphoma cells and induce the differentiation of these cells towards a mature plasma cell phenotype. Similar responses are seen when Daudi cells are treated with the phorbol ester, TPA. Both interferons and TPA down-regulate expression of the c-myc oncogene in these cells. Although TPA can mimic the effect of interferon on cell differentiation, it does not induce 2′5′ oligoadenylate synthetase or the interferon-sensitive mRNAs, 6-16 or 9-27. Thus chronic stimulation of protein kinase C by TPA cannot mimic all of the effects of interferon treatment on gene expression. Inhibition of ADP-ribosyl transferase activity by 3-methoxybenzamide impairs interferon- or TPA-induced differentiation of Daudi cells. This agent induces a higher level of c-myc mRNA in the cells and stimulates the incorporation of [3H]thymidine into DNA; although these effects are partially counteracted by interferon or TPA treatment, the elevated expression of the c-myc gene may be sufficient to prevent terminal differentiation and allow cell proliferation to continue.
    Additional Material: 3 Ill.
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  • 46
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 9 (1988), S. 13-22 
    ISSN: 0192-253X
    Keywords: ontogeny ; lethality ; gene expression ; mRNA ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Cadmium is a toxic metal that induces the expression of metallothionein genes in many tissues and that binds avidly to metallothionein, a soluble transition metal binding protein. The present study examined the temporal pattern and magnitude of accumulation of metallothionein mRNA in liver of C57BL/6J mice of various ages treated with cadmium. In adult female mice, accumulation was dependent on the dosage level of cadmium and related to the concentration of this metal in liver. The accumulation of metallothionein mRNA in liver depended on age at exposure to cadmium. Intraperitoneal administration of 2 mg of cadmium per kg provoked small increases (two- to threefold) in levels of metallothionein mRNA in livers of 7- and 14-day-old mice. In contrast, cadmium treatment of 28- and 56-day-old mice resulted in 12- to 19-fold increases in levels of metallothionein mRNA in liver with maximum increases occurring 3 to 4 hr after treatment. Because similar patterns for the accumulation of cadmium of liver were found in 7-, 28-, and 56-day-old mice, observed age-dependent differences in induction of metallothionein mRNA in liver were probably not due to differences in the accumulation of cadmium in this organ. Taken together, these data suggest that tissue-specific factors controlling the expression of metallothionein genes may account for developmental variation in the inducibility of these genes by cadmium. Ontogenic variation in accumulation of metallothionein mRNA after cadmium treatment may be a factor in developmental variation in the acute lethality of cadmium in C57BL/6J mice.
    Additional Material: 5 Ill.
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  • 47
    ISSN: 0192-253X
    Keywords: Daucus carota ; auxin ; gene expression ; mutant ; filtration-enrichment procedure ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Cell cultures of the carrot Daucus carota are a useful experimental system for studying the genetic regulation of plant embryogenesis. A modified filtration-enrichment procedure was used to isolate 21 temperature-sensitive variants in somatic embryogenesis; the variants display normal embryo development at the permissive temperature (24°C) and altered development at the restrictive temperature (33°C). Temperature-shift experiments were performed on these variants to determine the timing of gene action for the putative temperature-sensitive alleles. According to their phenotypes at the restrictive temperature, these variants can be divided into six classes: No Growth, Callus Proliferation, Globularstage Block, Oblong-stage Block, Lateral Growth, and Root Formation. Although many variants exhibit lengthy temperature-sensitive periods, the temperature sensitivity of some variants is restricted to one or two embryonic stages. These results plus those in the literature are incorporated into a preliminary model concerning the genetic regulation of carrot embryogenesis.
    Additional Material: 9 Ill.
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  • 48
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 9 (1988), S. 259-265 
    ISSN: 0192-253X
    Keywords: G-proteins ; gene expression ; developmental regulation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have identified a two-member gene family in the Dictyostelium genome and have isolated corresponding cDNA or genomic DNA recombinant clones. Analyses of these DNA sequences predicted encoded proteins of ∼200 amino acids with ∼90% sequence identity to each other. These Dictyostelium proteins also share amino acids identity within the GTP-binding domains in the family of G-regulatory proteins involved in cellular regulation and transmembrane signalling. Additional structural similarities are seen with members of the ras supergene family, such as ras, ral, and rho. They are similar in size (usually ∼200 amino acids), possess four conserved domains involved in GTP interaction and are believed to be anchored in the membrane by fatty acid modification of a cysteine residue near the carboxy terminus. More extensive identity is observed with YPT1 and SEC4, two other members of this family of genes that are essential in yeast. The amino-terminal half of both Dictyostelium proteins is 70% identical in amino acid sequence to the YPT1 and SEC4 yeast proteins with less identity continuing through the remainder of the proteins. In addition these proteins terminate in two cysteine residues that are thought to be required for membrane anchorage.The two genes within this Dictyostelium family are organized differently in the genome and are differentially regulated during development. One gene is colinear in sequence with its mRNA in the protein coding region, whereas the other gene encodes a spliced mRNA. The intron-containing gene is associated with a developmentally regulated (AAC)-repeat sequence. Finally, we have shown that the expression of one of the genes is induced during development with kinetics similar to that of other (AAC)n-associated genes; conversely, the expression of the second gene is repressed at a similar developmental stage.
    Additional Material: 3 Ill.
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  • 49
    ISSN: 0192-253X
    Keywords: cAMP ; Ca2+ ; signal transduction ; cell surface receptor ; gene expression ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Elevated levels of cAMP are essential for the expression of many postaggregation prespore and prestalk mRNA species and for the suppression of some growth phase mRNAs. Here we review evidence that this regulation is mediated by cAMP interacting at the cell surface receptor. These effects of cAMP on gene expression can occur under conditions where the receptor-associated adenylate cyclase is inactivated and in concentrations that are consistent with receptor binding. A number of differences are noted in the mechanism by which cAMP regulates prespore and prestalk genes. Finally, evidence is reviewed for the role of a Ca2+-dependent signal transduction system in coupling the expression of some of the prespore mRNAs to the cAMP receptor. This signal transduction system does not appear to be involved in the expression of the cAMP-dependent prestalk gene.
    Additional Material: 2 Ill.
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  • 50
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    Developmental Genetics 9 (1988), S. 167-180 
    ISSN: 0192-253X
    Keywords: enzyme pattern ; gene expression ; protein synthesis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Aldehyde oxidase (AO) and pyridoxal oxidase (PO) distribution patterns were determined in the imaginal wing discs for a series of strains of Drosophila melanogaster heterozygous for different Minute mutations. The mutant severity ranged from very weak to strong. The results show an inverse response of AO and PO to the expressivity of the Minute mutation: in weaker Minutes the extent of the AO positive area increases, whereas PO activity disappears. The results are discussed with reference to an impaired protein synthesis in Minutes.
    Additional Material: 6 Ill.
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  • 51
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    Cellular and molecular life sciences 43 (1987), S. 741-750 
    ISSN: 1420-9071
    Keywords: Hybridization histochemistry ; hybridocytochemistry ; in situ hybridization ; gene expression ; histochemical hybridization ; nucleic acid hybridization ; histocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The location of gene expression by hybridization histochemistry is being applied in many areas of research and diagnosis. The aim of this technique is to detect specific mRNA in cells and tissues by hybridization with a complementary DNA or RNA probe. Requirements for optimal specificity, sensitivity, resolution and speed of detection may not all be encompassed in one simple technique suitable for all applications, thus appropriate procedures should be selected for specific objectives. With reference to published procedures and our own extensive experience, we have evaluated fixatives, probes, labels and other aspects of the technique critical to the preservation and hybridization in situ of mRNA and detection and quantition of hybrids.
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  • 52
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    Molecular and cellular biochemistry 78 (1987), S. 3-8 
    ISSN: 1573-4919
    Keywords: polyamines ; RNA polymerase ; transcription ; gene expression ; mycobacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract All three polyamines — putrescine, spermidine and spermine stimulated the activity of mycobacterial RNA polymerase in vitro although the concentration required for maximal stimulation was different for each of the amines. Spermidine and spermine showed a biphasic effect on the enzyme activity. Stimulation of RNA synthesis by spermidine occurs only at higher DNA template/enzyme ratio. Spermidine stimulates RNA synthesis by acting on the elongation phase of RNA synthesis but it had no effect on initiation phase. Addition of mycobacterial RNA to the assay mixture resulted in the inhibition of RNA polymerase activity and this inhibition could be reversed by spermidine suggesting that spermidine stimulates transcription by binding to nascent RNA and thus destabilizing the short DNA-RNA hybrid region.
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  • 53
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    Molecular and cellular biochemistry 75 (1987), S. 61-70 
    ISSN: 1573-4919
    Keywords: gene expression ; development ; tissue-specific expression ; cell cycle-dependent genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract 4F1, 2A9 and 2F1 represent three of a number of cDNA sequences which have been identified because their cognate RNAs markedly increase when quiescent cells in culture are stimulated with serum. Studies using a variety of cell culture systems have shown that the expression of these genes is modulated by various growth factors and mitogens and thus such genes are considered to be ‘growth-associated.’ Thus far, little information has been obtained with these in vitro systems about the function of these genes. In an attempt to begin to elucidate the role of these genes (if any) in the physiology of the normal cell, we have analyzed the levels of 4F1, 2A9 and 2F1 transcripts in a variety of differentiated organs and tissues of adult and fetal rats. Our results show that each of these growth-associated genes exhibits its own unique pattern of expression, unrelated to the proliferative activity of the tissue. These data suggest that these genes most likely do have specific functions in normal tissue in addition to their role in the induction of DNA synthesis in quiescent cells in culture.
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  • 54
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    Bioscience reports 7 (1987), S. 955-963 
    ISSN: 1573-4935
    Keywords: gene expression ; GC box ; negative regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A DNA control sequence T G GGGCGG AAT GGC , or the “GC” box, has been described in the promoter regions upstream of a number of eukaryotic genes transcribed by polymerase II (for review, see Dynan, W. S. and Tjian, R.,Nature 316:774, 1985). The “GC” box can occur in single or multiple copies and is the binding site for a protein factor, Spl, which activates initiation of transcription. We have observed in the rainbow trout protamine gene 3′ to the TATA box, three “GC” boxes spaced at 80 bp intervals. The first is 5′ to the cap site and possesses the ability to “silence” transcription from the protamine promoter in constructs linking this promoter to the bacterial chloramphenicol acetyl transferase (CAT) coding sequence following transfection to COS-1 cells. A model is proposed to account for the silencing of the protamine gene in all tissues except developing sperm cells.
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  • 55
    ISSN: 1573-5028
    Keywords: azacytidine ; DNA/RNA hybridization ; gene expression ; marker rescue ; nopaline-synthase ; plant tumor cells ; Ti-plasmid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cell wall regenerating protoplasts from soybean cells kept in suspension culture were cocultivated with bacteria which were derived from the nopaline strain C58 of Agrobacterium tumefaciens. When the bacteria carried an oncogenic Ti-plasmid, about 5% of the surviving protoplasts were able to form calli on hormone-free agar in contrast to controls, where bacteria without Ti-plasmid were applied, and where no calli were formed. After isolation of DNA from hormone-independently growing cells further evidence for transformation was obtained by hybridization to Ti-plasmid specific RNA and by rescue of a segment with a bacterial resistance gene which had been inserted before into the T-DNA. Transfer of T-DNA harboring a neomycin-resistance gene activated by the nos-promoter resulted in calli growing on kanamycin. Verification of segments located at the left and the right part of the T-DNA indicated the presence of its entire length in transformed soybean cells. Expression of T-DNA genes was measured by the assay of nopaline-synthase. Cells cultured on agar had a much higher level of nopaline-synthase than fast growing cells in suspension culture. Transferring them to agar or treatment with azacytidine strongly increased synthesis of nopaline-synthase indicating a reversible repression presumably via a methylation mechanism.
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  • 56
    ISSN: 1573-5028
    Keywords: cucumber ; gene expression ; hydroxypyruvate reductase ; light regulation ; peroxisomal enzymes ; serine:glyoxylate aminotransferase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The development of peroxisomal enzymes in cotyledons of cucumber seedlings is strongly dependent on light. In light-grown seedlings, activities of two peroxisomal enzymes, hydroxypyruvate reductase (HPR) and serine: glyoxylate aminotransferase (SGAT), were barely detectable until three days postimbibition, after which time both activities increased rapidly and linearly for at least three days. In the dark, the activities of these enzymes increased slightly over the same time period, but only to about 5% to 10% of 7-day light-induced levels. When 51/2-day dark-grown seedlings were transferred into white light, activities of HPR and SGAT began to increase after approximately 8 h. HPR protein was shown by an immunoprecipitation assay to increase concurrently with enzymatic activity in both light- and dark-grown cotyledons. Immunoblotting results suggested that the amounts of SGAT-A and SGAT-B, the two subunits of SGAT, also developed along with SGAT activity. The relative levels of translatable mRNAs encoding HPR, SGAT-A, and SGAT-B were also light-dependent, and increased with a developmental pattern similar to enzyme activity and protein levels in light- and dark-grown cotyledons. In 51/2-day dark-grown cotyledons that were transferred to the light, translatable mRNAs for SGAT-A and SGAT-B began to increase within 1 h of illumination and continued of increase rapidly and linearly for the next 24 h in the light to a new steady-state level that was 45 times that of dark controls. Translatable HPR mRNA exhibited a biphasic pattern of accumulation, with a three-fold increase during the first 6 h of illumination, followed by an additional six-fold increase between 8 and 24 h. The accumulation of translationally active mRNA for both enzymes preceded the accumulation of the corresponding protein and enzyme activity by about 8 h. Our data suggest that the rise in enzyme activity depends on an increase in translatable mRNA for these enzymes and is regulated at a pretranslational level, most likely involving transcription of new mRNA.
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  • 57
    ISSN: 1573-5028
    Keywords: gene expression ; nitrogen fixation ; nodulins ; Phaseolus vulgaris ; Rhizobium ; root-nodule development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The identification of some nodule-specific host proteins (nodulins) from common bean (Phaseolus vulgaris L.), a tropical ureide-transporting legume, is described. Particularly, the existence and developmental expression of several abundant nodule-specific transcripts of P. vulgaris are shown, including leghemoglobin, nodulespecific uricase and a group that in vitro translates into a cluster of about 30 kDa products. The expression pattern of nodulins in effective (Fix+) nodules compared to ineffective (Fix-) ones is also presented. The modified expression of main nodulins observed between these nodules indicates that different levels and/or factors associated with their regulation are involved. The intracellular infection by Rhizobium as a decisive step in the induction of some P. vulgaris nodulins is discussed.
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  • 58
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    Plant molecular biology 9 (1987), S. 547-563 
    ISSN: 1573-5028
    Keywords: acetate ; blue light ; Chlamydomonas reinhardtii ; chlorophyll a/b-binding protein gene ; gene expression ; LHCP gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In Chlamydomonas reinhardtii, the chlorophyll a/b-binding proteins of photosystem II are encoded in the nucleus by a small family of genes. We have studied the expression of one gene, which we call cabII-1, in a green-in-the-dark strain, which can synthesize chlorophyll in the dark or light, and in a yellow-in-the-dark mutant strain, which is able to make chlorophyll only in the light. In light/dark synchronized cultures of both strains, cabII-1 mRNA abundance increases during the first 6 h of a 12-h light phase, remains high for several hours, then declines. A variety of illumination conditions have been used to analyze the cabII-1 mRNA increase: continuous or intermittent red, blue, or white light, with or without 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), an inhibitor of photosystem II. Our results suggest that light induces increased cabII-1 transcript abundance in two ways: 1) by virtue of its role in the light reactions of photosynthesis and 2) by a blue lightstimulated mechanism which is independent of photosynthesis. We have also examined the role of acetate in regulating cabII-1 mRNA levels in the dark. In both green- and yellow-in-the-dark strains, 15 mM Na-acetate, added to synchronized cells in the dark, induces an increase in cabII-1 mRNA abundance with a temporal accumulation pattern very similar to that induced by continuous white light. We suggest that by providing an energy source, acetate stimulates cellular growth, cell cycle progression, and increased cabII-1 mRNA abundance. Interestingly, in cells exposed to light, acetate inhibits the light-induced increase in cabII-1 mRNA abundance by a mechanism which is not yet understood.
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  • 59
    ISSN: 1573-5028
    Keywords: abscisic acid ; aleurone layer ; α-amylase ; gene expression ; gibberellic acid ; isozymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The treatment of barley aleurone layers with gibberellic acid (GA3) results in the synthesis of two groups of α-amylase isozymes. Addition of abscisic acid (ABA) at the same time as GA3 inhibited the synthesis of both groups of isozymes. However, midcourse ABA addition (12 h or later after GA3) had a more inhibitory effect on the high pI α-amylase group than on the low pI α-amylase group. This midcourse inhibition was detectable within 2 h of ABA addition. Northern analysis results using cDNA probes for the high pI and low pI α-amylase groups paralleled the protein synthesis results for both isozyme groups. High pI α-amylase mRNA levels began to decrease within 2 h of midcourse ABA treatment and were less than 10% of the original level by 4 h. The levels of low pI α-amylase mRNA were decreased less by midcourse ABA addition than were high pI mRNA levels. Cordycepin and cycloheximide blocked the effects of midcourse ABA addition on α-amylase mRNA. These observations indicate that ABA inhibits α-amylase expression at the pretranslational level and that protein and RNA synthesis are required for midcourse ABA action to occur. Our results also show that α-amylase mRNA, which has been thought to be very stable, is degraded after midcourse ABA treatment.
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  • 60
    ISSN: 1573-5028
    Keywords: plant transformation ; CaMV promoters ; gene expression ; protein stability ; beta-conglycinin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A gene encoding the α′-subunit of β-conglycinin was ligated to the 19S and 35S promoters of Cauliflower Mosaic Virus and introduced into petunia plants on a disarmed Ti-plasmid using Agrobacterium tumefaciens. Transformed cells were regenerated into whole plants and ummunoreactive polypeptides and hybridizable, polyadenylated mRNA were detected in transformed tissues. Expression from the 35S promoter was 10 to 50 times greater than expression from the 19S promoter. The level of immunodetectable polypeptides was greater in seeds than in leaves or callus tissue. In addition, the pattern of α′-polypeptide breakdown products was distinctive in seeds and leaves. We conclude that in seeds the higher levels of the α′-polypeptide reflect enhanced stability of this protein.
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  • 61
    ISSN: 1573-5028
    Keywords: hypersensitive response ; Brassica campestris ; Xanthomonas campestris pv. vitians ; mRNA induction ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Xanthomonas campestris pv. vitians, a pathogen of lettuce, elicits a hypersensitive response within 12 hours of inoculation into Brassica leaves, characterized by tissue collapse, loss of membrane integrity, vein blockage and melanin production. In contrast, the compatible pathogen, X. c. pv. campestris, has no visible effects on leaves for 48 hours, after which inoculated areas show chlorosis which eventually spreads, followed by rotting. mRNA was prepared from leaves inoculated with suspensions of both pathovars or with sterile medium up to 24 hours following inoculation. In vitro translation of total and poly A+ RNA in rabbit reticulocyte lysate in the presence of 35S methionine followed by separation of the polypeptide products by 2D-PAGE, allowed comparison of the effects of these treatments on plant gene expression. Major changes in gene expression were observed as a consequence of the inoculation technique. In addition, after inoculation with X. c. vitians, up to fifteen additional major polypeptides appeared or greatly increased by four hours. Some of these had disappeared by nine hours and several more had appeared. No major polypeptides disappeared or decreased greatly in intensity following inoculation with X. c. vitians.
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  • 62
    ISSN: 1573-5028
    Keywords: coordinate regulation ; Cucurbita phytochrome cDNA ; gene expression ; light regulation ; multiple transcripts ; regulatory photoreceptor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have isolated several cDNA clones for phytochrome from a dicot, Cucurbita pepo L. cv. Black Beauty (zucchini), and have used them to study the regulation of Cucurbita phytochrome mRNA levels. A cDNA library was constructed from poly(A)+ RNA isolated from etiolated Cucurbita hypocotyl hooks and enriched for phytochrome mRNA by size fractionation. This library was screened with a 32P-labeled fragment isolated from an Avena phytochrome cDNA clone. Several putative phytochrome clones were isolated and mapped by restriction endonuclease analysis. On the basis of this analysis there is no evidence for the expression of multiple phytochrome genes in Cucurbita. Recent sequence analysis has confirmed that the largest of these clones, pFMD1 (∼3.6 kb), does indeed encode phytochrome and that it contains the entire amino acid coding sequence for Cucurbita phytochrome (33). RNA blot analysis has revealed that two polyadenylated phytochrome transcripts (∼5.6 kb and ∼4.2 kb) are present in both cotyledons and hypocotyl hooks of Cucurbita. In etiolated Cucurbita seedlings given a saturating pulse of red light, the abundance of both transcripts coordinately declines to 50–60% of the dark levels within 3 h and reaccumulates to dark levels within 24 h. Reversal of induction of this response by a far-red light pulse immediately following red light treatment is not observed, which is in contrast to the far-red reversibility of the red light promoted decrease in phytochrome mRNA abundance observed in Avena (6). Etiolated seedlings transferred to continuous white light also show a coordinate decrease in the levels of the two RNAs to ∼40% of the dark levels within 3 h. The magnitude of the light-induced decline in phytochrome mRNA abundance in Cucurbita is substantially less than the decrease previously reported for Avena (6).
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  • 63
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    Cancer and metastasis reviews 6 (1987), S. 503-520 
    ISSN: 1573-7233
    Keywords: animal models ; chemotherapy ; gene expression ; metastasis ; tumour progression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Cancer chemotherapy is currently undergoing an intensive reappraisal because of its unimpressive performance against the major common cancers. There are a number of possible reasons for this lack of success; one considered here is that under some circumstances anti-neoplastic drug treatment actually increases the malignant behaviour of tumours. Support for this idea comes mainly from experimental studies in which drug treatments increased metastatic spread. Investigation of this phenomenon shows that drug induced modifications of the host, including immunosuppression and vascular damage, can indeed facilitate metastasis. In addition, new data are presented demonstrating that the direct action of drugs on the tumour cells themselves can have similar enhancing effects. The possible mechanisms underlying such direct effects are discussed and the ability of anti-cancer drugs to cause genetic mutations, amplify genes, and alter gene expression are considered. While the nature and extent of this facilitation of tumour malignancy is not fully understood, it is suggested that this possibility should be considered in the design of treatment protocols.
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  • 64
    ISSN: 1572-994X
    Keywords: EBV ; gene expression ; immortalization ; cDNA cloning ; Northern blot hybridization ; tonsil lymphocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two infection systems have been introduced in order to study viral gene expression at the initial period of Epstein-Barr virus (EBV) infection which leads to immortalization. The data indicate that major viral gene expression in tonsil lymphocytes at 2 days post-infection (p.i.) with EBV is very similar to that observed in latently infected cells. Both tonsil lymphocyte and BJAB cell (lymphoblastoid cells free of EBV genome) infection with EBV induced similar viral gene transcription. Twelve cDNA clones were prepared from poly(A) RNA of tonsil lymphocytes infected with EBV 2 days p.i. by hybridization with BamHI fragments of EBV DNA. Some cDNAs were derived from primary transcripts of the BamHI-WYHK region, suggestive of splicing of a large transcript. It is possible that a number of cDNA clones may be derived from cellular genes. The derivation of these cDNA clones is being studied.
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  • 65
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    Plant molecular biology 8 (1987), S. 251-264 
    ISSN: 1573-5028
    Keywords: chromatin structure ; DNase I hypersensitivity ; gene expression ; sucrose synthetase ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The local chromatin structure of the Shrunken-1 (Sh) gene of maize was probed by analyzing DNase I hypersensitivity. Sh encodes the gene for sucrose synthetase, a major starch biosynthetic enzyme, which is maximally expressed in the endosperm during seed maturation. In addition to general DNase I sensitivity, specific DNase I hypersensitive sites were identified in endosperm chromatin that mapped near the 5′ end of the Sh gene. The pattern of hypersensitive sites and their relative sensitivity were altered in other non-dormant tissues that produce little or no enzyme. However, some changes in chromatin structure appear to be independent of Sh gene expression and may reflect general alterations associated with plant development. The chromatin structure of several sh mutations, induced by Ds controlling element insertions, was also analyzed. Although the insertions perturbed expression of the gene, there were no notable effects on local chromatin structure.
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  • 66
    ISSN: 1573-5028
    Keywords: Bradyrhizobium ; gene expression ; nodulin ; soybean
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In vitro translation products of total RNA isolated from soybean nodules at successive stages of nodule development were analyzed by two-dimensional gel electrophoresis. In that way the occurrence of over 20 mRNAs specifically transcribed from nodulin genes was detected. The nodulin genes could be divided into two classes according to the time of expression during nodule development. Class A comprises at least 4 nodulin mRNAs which are found when a globular meristem is present in the root cortex. These class A nodulin genes have a transient expression. Class B nodulin genes are expressed when the formation of a nodule structure has been completed. Bradyrhizobium japonicum nod + fix-mutants, with large deletions spanning the nif H,DK region, still induced nodules showing normal expression of all nodulin genes, indicating that the nif H,DK region is not involved in the induction of nodulin genes. In nodules induced by Bradyrhizobium japonicum nod + fix-mutant HS124 the bacteria are rarely released from the infection thread and the few infected cells appear to be collapsed. All class A and class B nodulin genes are expressed in HS124 nodules with the exception of 5 class B genes.
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  • 67
    ISSN: 1573-5028
    Keywords: potato tuber ; elicitor ; arachidonic acid ; cDNA cloning ; gene expression ; PR proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Accumulation of messenger RNAs in potato tuber discs was analysed during the hypersensitive response induced by treatment with the biotic elicitor arachidonic acid. In vitro translation of polysomal poly(A)+ RNAs indicated that the accumulation of some sixteen mRNAs varied following treatment with arachidonic acid, and that the level of thirteen of these was increased. Two cDNA closes (pSTH-1 and-2) were isolated from a library of elicitor-treated tissue cDNAs. Northern blot analysis using these clones as molecular probes indicated that the levels of at least two mRNAs were markedly increased after elicitor treatment. In hybrid-released translation experiments, each of the cDNA clones selected more than one mRNA. Translation of these mRNAs yielded two polypeptides of Mr 45 000 (for the pSTH-1 clone), and three polypeptides of Me 17 000 (for the pSTH-2 clone). The low molecular weight polypeptides may correspond to potato pathogenesis-related (PR) proteins.
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  • 68
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    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 34 (1987), S. 13-22 
    ISSN: 0730-2312
    Keywords: TPA ; tumor promotion ; JB6 cells ; transcriptional induction ; inducible mRNA ; 2ar mRNA ; mRNA induction ; serum-inducible ; JB6 ; TPA ; tumor promoter ; nuclear “run-off” transcription ; gene expression ; colony screening ; mRNA ; growth factors ; competence ; 3T3 fibroblasts ; protein kinase C ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: From the mouse JB6 epidermal cell line C122 we have isolated a cDNA clone representing a 1.6-kilobase mRNA, called 2ar, that exhibits a biphasic induction in response to 12-O-tetradecanoyl-phorbol-13-acetate (TPA). The first phase of induction in subconfluent cells is transient, peaking at 6 h after the addition of TPA and returning to noninduced levels by 24 h. When the cells reach plateau density, in the continued presence of TPA, this mRNA is reinduced and remains so upon continued exposure to the tumor promoter. Serum and certain growth factors also induce 2ar mRNA in serum-deprived quiescent fibroblasts. In vitro nuclear “run-on” transcription experiments indicate that the induction of 2ar mRNA is controlled at the transcriptional level.
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  • 69
    ISSN: 0148-7280
    Keywords: immunofluorescence ; early development ; gene expression ; H-Y antigen ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: An indirect immunofluorescence assay was used to detect the presence of male-specific protein(s) on various stages of preimplantation porcine embryos. Embryos were collected at slaughter from the reproductive tracts of day-2.5, -4, -5, -6, and -8 (day 0 = first day of estrus) sows and gilts. Embryos were placed in medium containing an anti-male primary antibody, washed, and transferred to culture drops containing a fluorescein isothiocyanate (FITC)-labeled secondary antibody. Embryos were classified as either fluorescent (H-Y positive) or nonfluorescent (H-Y negative), transferred to coded drops, and karyotyped to examine sex chromosomes. A total of 91 eight-cell to blastocyst stage embryos were evaluated; of these, 46% were classified as fluorescent and 54% as nonfluorescent. Of readable metaphase spreads (65%) from these embryos, 81% (48 of 59, P 〈 0.005) were correctly sexed by immunological detection of the male-specific antigen. Although 13 % (2/15)of four-cell embryos evaluated were classified as fluorescent, the accuracy with which embryos at this stage were sexed by detection of H-Y antigen was not different from 50%. Fifty percent of eight-cell embryos were classified as H-Y positive with 78% of embryos correctly sexed. It was concluded that the eight-cell embryo is the earliest stage of development for which there is evidence for expression of H-Y antigen. Detection of the male-specific protein was difficult at the expanded blastocyst stage.
    Additional Material: 2 Tab.
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  • 70
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 125-133 
    ISSN: 0192-253X
    Keywords: retrovirus ; embryonal carcinoma ; embryonic gene ; DNA methylation ; gene expression ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Northern blot analysis and in vitro nuclear transcription assays were performed in order to clarify conflicting reports on the expression of intracisternal A particle (IAP) genes in embryonal carcinoma (EC) cell lines. Results demonstrate that post-transcriptional mechanisms control the final steady-state levels of IAP RNA in EC cells. IAP genes were further found to be undermethylated in IAP-expressing EC cell lines.
    Additional Material: 5 Ill.
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  • 71
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 149-160 
    ISSN: 0749-503X
    Keywords: DNA repair ; RAD2 ; Saccharomyces ; gene expression ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The cloned RAD2 gene of S. cerevisiae was tailored into regulatable expression vectors for overexpression of Rad2 protein in E. coli and in yeast. In E. coli both Rad2/β-galactosidase fusion protein and native Rad2 protein are insoluble, but are extractable with 1% Sarkosyl. In yeast some of the overexpressed native Rad2 protein is also insoluble; however, soluble protein is readily detected by immunoblotting with Rad2-specific antibodies. All forms of the protein detected in transformed or untransformed yeast cells and the insoluble species in E. coli migrate in denaturing polyacrylamide gels with an apparent molecular weight considerably larger than the size predicted from the sequence of the RAD2 coding region. This property is not the result of post-translational glycosylation detectable by binding of concanavalin A, or of phosphorylation of the protein. Overexpression of the RAD2 gene is toxic to yeast. Transformed yeast cells grow much more slowly than untransformed controls and when yeast transformants are serially propagated cultures show considerable colony heterogeneity and concomitant selection for rapidly growing variants which express less Rad2 protein. Antisera raised against Rad2/β-galactosidase fusion protein expressed in E. coli do not cross-react with Rad1, Rad3 or Rad10 protein in crude extracts of yeast, nor with purified E. coli UvrA, UvrB or UvrC proteins.
    Additional Material: 8 Ill.
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  • 72
    ISSN: 1573-4919
    Keywords: cell cycle ; gene expression ; oncogenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary A number of genes and cDNA sequences (including at least four oncogenes) are known to be expressed in a cell cycle-dependent manner, i.e. the levels of specific mRNAs vary with the phases of the cell cycle. In order to explore the significance of some of these sequences in the mitogenic response, we have investigated the expression of 8 cell cycle-dependent sequences (plus two control sequences, not expressed in a cell cycle-dependent manner) under a variety of conditions. These conditions included cells of different types, from different species, stimulated to proliferate by different mitogens. The genes (or sequences) studied included five cDNA clones whose sequences are preferentially expressed in early G1, i.e. two cDNA clones inducible by platelet-derived growth factor (JE-3 and KC-1), and three cDNA clones inducible by serum (2A9, 2F1, 4F1); and three oncogenes (c-myc, c-rasHa and p53) whose expression is known to be cell cycle-dependent. All of the tested genes, except 2A9, c-rasHa and the control genes, are expressed in a cell cycle-dependent manner in human peripheral blood mononuclear cells stimulated by phytohemagglutinin and in serum-stimulated mouse and Syrian hamster fibroblasts. The inducibility of these genes by different mitogens in cells of different types and from different species strongly suggests that these genes play a role in cell cycle progression. This conclusion is further supported by the known structural and functional similarities between cell-cycle dependent genes, oncogenes and genes coding for cell-cycle related molecules.
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  • 73
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    Electronic Resource
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    Bioscience reports 6 (1986), S. 621-631 
    ISSN: 1573-4935
    Keywords: brown adipose tissue ; thermogenin ; uncoupling protein ; gene expression ; adrenergic effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract By the use of an earlier characterised cDNA clone, CIN-1, corresponding to a sequence of the mRNA coding for the brown-fat specific “uncoupling” protein, thermogenin, the amount of thermogenin mRNA found in the brown adipose tissue of mice was quantitatively investigated under different physiological and pharmacological conditions. It was found that a 4 hr cold stress led to a 7-fold increase in the amount of thermogenin mRNA; injection of norepinephrine had a significant but smaller effect. Most notably, isoprenaline (β-agonist) and phenylephrine (α-agonist) had in themselves no effect, but when injected together were able to increase the mRNA level synergistically. In 4 hr cold-stressed mice, norepinephrine, isoprenaline and cholera toxin could all further potentiate the effect of the cold stress itself on the mRNA level. Insulin and the glucocorticoid dexamethasone both had weak stimulatory effects on the mRNA level. It is concluded that an increase in intracellular cAMP levels is a necessary and perhaps sufficient stimulus for the increase in thermogenin gene expression. However, at least underin vivo conditions, this increase requires stimulation of both α- andβ-adrenergic pathways.
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  • 74
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    Plant molecular biology 7 (1986), S. 51-61 
    ISSN: 1573-5028
    Keywords: Soybean ; Rhizobium ; nitrogen fixation ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Nodulins are organ-specific plant proteins induced during symbiotic nitrogen fixation. Nodulins play both metabolic and structural roles within infected and uninfected nodule cells. In soybean, several nodulin genes, coding for abundant nodulins, have been identified and isolated. Structural analysis of some of these genes has revealed their possible mode of regulation and the subcellar location of the protein product. Studies of ineffective symbiosis based on cultivar-strain genotype differences suggested that both partners influence the expression of nodulin genes. Concomitant with nodule organogenesis, the Rhizobium undergoes substantial differentiation leading to the accumulation of nodule-specific bacterial proteins, bacteroidins. The major structural alteration occuring in the infected cell is the formation of a membrane enclosing the bacteroid (peribacteroid membrane). A number of nodulins are specifically targetted to this membrane during endosymbiosis. The induction of nodulins and bacteroidins leads to the formation of an effective nodule. Nodulin genes can be induced in vitro by factors derived from nodules suggesting that trans-activators may be involved in derepression of the host genes necessary for Rhizobium-legume symbiosis.
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  • 75
    ISSN: 1573-5028
    Keywords: Agrobacterium rhizogenes ; Solanum tuberosum ; T-DNA ; gene expression ; tuberisation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Expression of TL-DNA from Agrobacterium rhizogenes plasmid pRi 1855 was examined in a transformed derivative of Solanum tuberosum cv. Desiree, D9X8a. Northern blot analysis identified at least nine TL-DNA coded transcripts in roots, shoots and tubers but their relative abundance differed within and between organs. This revealed a distinctive pattern of organ specified differential expression. Grafting experiments showed that the abnormal shape of tubers of transformed potato was probably determined by TL-DNA products synthesised within the tuber and not by diffusable products synthesised in other parts of the plant. The abundance of at least one transcript, tr5, was probably determined by culture conditions. Implications for functions and control of expression of Ri TL-DNA genes are discussed. It is suggested that Ri TL-DNA provides a convenient and extensive set of model genes to study variation and stability of expression of linked foreign genes introduced into plants.
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  • 76
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    Electronic Resource
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 1 (1986), S. 116-124 
    ISSN: 0887-3585
    Keywords: translational repressor ; in vitro transcription-translation ; gene expression ; protein purification ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The bacteriophage T4 translational represor regA protein has been purified from an overproducing strain, and its activity has been studied in simple in vitro protein synthesis reactions. RegA protein was found to inhibit the translation of T4 genes 44, 45, and ORF45-1 in a concentration-dependent fashion. Expression of two other T4 genes which are insensitive to regA protein in vivo, genes 32 and 43, was unaffected by the presence of regA protein. Specific inhibition of synthesis of genes 44, 45, and ORF 45-1 proteins was achieved with 5-20 μM concentrations of regA protein, without the addition of any other T4 encoded proteins or cofactors. When in vitro protein synthesis was performed in two steps, uncoupling translation from transcription, regA protein had an inhibitory effect regardless of whether it was added at the initiation of transcription or only at the translation step. This indicates that regA protein functions during the translation step of protein synthesis in vitro in agreement with previous in vivo studies of regA protein.
    Additional Material: 7 Ill.
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  • 77
    ISSN: 0730-2312
    Keywords: tumor metastasis ; gene expression ; oncogenes ; virus antigens ; glycoproteins ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: A metastatic variant cell subline of the Abelson virus-transformed murine large lymphoma/lymphosarcoma RAW 117 has been selected in vivo ten times for liver colonization. Highly metastatic subline RAW117-H10 forms greater than 200 times as many gross surface liver tumor nodules as the parental line RAW117-P. Analysis of cellular proteins and glycoproteins indicates reduced expression of murine Moloney leukemia virus-associated p15, p30, and gp70, and increased expression of a sialoglycoprotein, gp150, in the highly metastatic H10 cells. Northern analyses of oncogene expression suggested that mRNA of various oncogenes was expressed equally or not expressed in the RAW117 cells of differing metastatic potential. Differential gene expression was examined using a cDNA library of 17,600 clones established from poly A+ mRNA isolated from H10 cells. The cDNA library was screened by the colony hybridization technique using probes made from both RAW117-P and -H10 cells. Approximately 99.5% of these cDNA clones were expressed identically in P and H10 cells. Of the few differentially expressed cDNA clones (approx. 150/17,600), one-half of these were identified as Moloney leukemia virus sequences in a separate probing with a radiolabeled Moloney leukemia virus probe. The remainder of the differentially expressed mRNA detected by colony hybridization of the cDNA library were expressed at higher levels (approx. 1/6) or lower levels (approx. 1/3) in the highly metastatic H10 cells.
    Additional Material: 3 Ill.
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  • 78
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 7 (1986), S. 149-158 
    ISSN: 0192-253X
    Keywords: macronucleus ; gene expression ; cell union ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We report here the presence of N6-methyladenine (MeAde) in the macronuclear DNA (maDNA) of Blepharisma japonicum vegetative cells. We have further investigated the relationship between DNA methylation and cell union in cells activated for conjugation. Such activation was induced by treating cells of mating type I with complementary gamone 2. We found a reduction of about 24% of MeAde content in gamone-treated cells ready for cell union. First indications of the presence and reduction of MeAde content came from electrophoresis of maDNA digested by appropriate restriction endonucleases. Chromatographic determination of the amount of methylated base by HPLC substantiated these observations. In vegetative cells, 1.576 ± 0.02% of total adenine was found to be methylated as opposed to 1.193 ± 0.04% in activated cells. The HPLC analysis of maDNA also revealed a peak with a retention time corresponding to that of 5-hydroxymethyluracil, already found in some species of dinoflagellates. In that gamone treatment is correlated with a differential gene expression (indicated by a differential RNA and protein synthesis), our results suggest that there is a relationship between macronuclear genome activation and demethylation of maDNA. This is the first report of a correlation between gene activation and adenine demethylation in a eukaryotic organism.
    Additional Material: 4 Ill.
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  • 79
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    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 3 (1986), S. 59-73 
    ISSN: 0739-4462
    Keywords: gene expression ; chorion ; homology ; cockroach ; oothecin ; juvenile hormone ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Control of specific protein synthesis by juvenile hormone during sexual maturation and reproduction is being studied in the left colleterial gland of the cockroach Periplaneta americana. Rates of specific oothecin synthesis and oothecin mRNA concentrations have been measured during sexual maturation and the effects of allatectomy and administration of juvenile hormone determined. The heterogeneity of the oothecins has been characterized and found to be due probably to a multiplicity of structural genes. The complete primary structure of the major oothecin has been deduced from the sequences of cloned cDNAS. It can be divided into a central region and two flanking arms that share sequence features. The structures of the oothecins show strong homologies with the silkmoth chorion proteins.
    Additional Material: 6 Ill.
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  • 80
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    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 3 (1986), S. 119-132 
    ISSN: 0739-4462
    Keywords: Ecdysone ; cuticle proteins ; gene expression ; Drosophila ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The deposition and apolysis of insect cuticles have long been known to be regulated by ecdysone. Unsclerotized, chitin-containing procuticles contain evolutionarily conserved, hydrophobic proteins that are soluble in solutions of denaturing agents. The pupal procuticle of Drosophila is deposited by larval and imaginal epidermis starting 9 h after puparium formation when the ecdysone titer is low. Initially, a set of low molecular weight proteins (less than 25,000 daltons; low molecular weight pupal cuticle proteins = S-PCPs) is synthesized. However, about the time of pupation, synthesis of S-PCPs ceases, and high molecular weight proteins (greater than 50,000 daltons; H-PCPs) are synthesized. In vitro experiments indicate that the initial formation of the procuticle with synthesis of the S-PCPs requires a pulse of hormone followed by withdrawal (6 h with 20-hydroxyecdysone, 1 μg/ml). The switch from synthesis of S-PCPs to H-PCPs is facilitated by a second, short pulse of 20-hydroxyecdysone (0.1 μg/ml, 3 h). Ultrastructural localization demonstrates that the S-PCPs are located only in the external lamellae of the procuticle, while the H-PCPs are present only in internal lamellae. Developmental analyses with cloned genes indicate that cuticle protein genes are expressed during only one stage of Drosophila development. Some of the genes encoding S-PCPs are limited in their expression to larval (posterior) or imaginal (anterior) epidermis. Preliminary molecular analyses of the larval and pupal cuticle protein genes indicate that they are organized in different ways. For example, four larval genes exist in a cluster with divergent transcription, and one PCP gene, PCP-GART, is located within an intron of a “housekeeping” gene.
    Additional Material: 5 Ill.
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  • 81
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    Biochemical genetics 23 (1985), S. 155-167 
    ISSN: 1573-4927
    Keywords: alkaline phosphatase ; gene expression ; inbred strains ; quantitative variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Quantitative alkaline phosphatase (ALP; EC 3.1.3.1) expression varies among various tissues and among inbred mouse strains. There is about a 20-fold difference in ALP activity in lungs from CBA/J and C57L/J inbred strains and this difference is inherited additively with a heritability of 0.84. Studies of thermostability at 56 and 65° C and sensitivity toward inhibitors (l-phenylalanine, l-homoarginine, l-phenylalanylglycylglycine, and levamisole) do not demonstrate differences in the ALP from lungs or liver of the CBA/J and C57L/J strains. The ALP activity in intestine expressed by the intestinal locus varies over 100-fold between A/J and DBA/1J strains. Further studies of the mechanisms resulting in this difference in ALP activity should help elucidate the mechanisms for aberrant expression of ALP in malignancy and for manipulation of low ALP activity in hypophosphatasia.
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  • 82
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    Biochemical genetics 23 (1985), S. 987-996 
    ISSN: 1573-4927
    Keywords: alcohol dehydrogenase ; temporal genes ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Alcohol dehydrogenase (EC 1.1.1.1) activity was measured in liver extracts from one outbred and three inbred strains of rats. Strain-specific differences in enzyme activity were observed in the adult male rats. The differences appeared as the animals reached puberty. Studies on the enzyme purified from Sprague-Dawley and ACI rats indicate that the enzymes in these strains are identical and that the difference in activity found in liver extracts is due to differences in the amount of enzyme present. Genetic crosses between Sprague-Dawley and ACI rats suggest that the liver content of alcohol dehydrogenase is controlled by an autosomal regulatory locus with the characteristics of a temporal gene.
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  • 83
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    Plant molecular biology 5 (1985), S. 91-101 
    ISSN: 1573-5028
    Keywords: gene expression ; low-abundance mRNA ; mRNA quantitation ; rapid regulation ; regulatory photoreceptor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Pure phytochrome RNA sequence synthesized in an SP6-derived in vitro transcription system has been used as a standard to quantitate phytochrome mRNA abundance in Avena seedlings using a filter hybridization assay. In 4-day-old etiolated Avena seedlings phytochrome mRNA represents ∼0.1% of the total poly(A)+ RNA. Irradiation of such seedlings with a saturating red-light pulse or continuous white light induces a decline in this mRNA that is detectable within 30 min and results in a 50% reduction by ∼60 min and 〉90% reduction within 5 h. The effect of the red-light pulse is reversed, approximately to the level of the far-red control, by an immediately subsequent far-red pulse. In seedlings maintained in extended darkness after the red-light pulse, the initial rapid decline in phytochrome mRNA level is followed by a slower reaccumulation such that 50–60% of the initial abundance is reached by 48 h. White-light grown seedlings transferred to darkness exhibit a similar accumulation of phytochrome mRNA that is accelerated by removal of residual Pfr with a far-red light pulse at the start of the dark period. The data establish that previously reported phytochrome-regulated changes in translatable phytochrome mRNA levels result from changes in the physical abundance of this mRNA rather than from altered translatability.
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  • 84
    ISSN: 1573-5028
    Keywords: Agrobacterium tumefaciens ; gene expression ; potato ; T-DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In potato line Mb1501B one or possibly two normal size Ti TL-DNA copies per tetraploid genome were detected by Southern blot analysis, but no TR-DNA. The TL-DNA probably contained the entire transposon Tn1831 inserted at the T-DNA auxin gene for transcript 2. Northern blot analyses of the steady-state RNA in different Mb1501B tissues isolated from (i) shoots cultured in vitro (ii) grafted plants and (iii) tubers, showed that that TL-DNA transcripts 3, 4, 6a and 7 were expressed most abundantly in the cultured shoots. They formed approximately 0.0023 to 0.0007% of the total poly(A) RNA. Transcripts 1, 5 and 6b were not detected in any of the tissues analysed. This indicated even lower levels of expression (below approximately 0.0001% of the total poly(A) RNA or, making certain assumptions, an abundance of less than one T-DNA derived RNA molecule per cell). As expected, transcript 2 was not detected in any of the Mb1501B tissues. The abundance of the transcripts was reduced in grafted plants and tubers compared with cultured shoots with the greatest decrease (5×) for transcripts 4, 6a and 7. Transcript 4, the one most responsible for the changed growth and development of Mb 1501 B, formed approximately 0.0003% of the poly(A) RNA from both grafted plants and tubers.
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  • 85
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    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 28 (1985), S. 105-113 
    ISSN: 0730-2312
    Keywords: collagen synthesis ; collagen mRNA ; gene expression ; cell culture ; scleroderma ; fibroblast ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Fibroblasts cultured from affected skin areas of five patients with cutaneous scleroderma were found to produce increased amounts of collagen when compared with nonaffected control cells. Total RNA was isolated from the cultures and analyzed for its level of proα1(I)collagen mRNA by hybridization of RNA blots with a cloned cDNA probe. The levels of proα1(I)collagen mRNAs relative to total RNA were two- to sixfold higher in the samples from affected cells, accounting for the increased synthesis of type I collagen. Cytoplasmic dot hybridizations were performed to measure the cellular content of proα1(I)collagen mRNA: up to ninefold increases in the level of this mRNA per cell were found. Upon subculturing, scleroderma fibroblasts were found to reduce gradually the increased synthesis of collagen to the level of non-affected controls by the tenth passage. The levels of type I collagen mRNAs were also reduced, but more slowly. The results suggest that in scleroderma fibroblasts the genes for type I collagen are activated at procollagen mRNA level or that they are more stable and that the activating factors are lost during prolonged cell culture because cells from affected areas lose their activated state.
    Additional Material: 3 Ill.
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  • 86
    ISSN: 1573-5060
    Keywords: microprotoplast fusion ; partial genome transfer ; monosomic additions ; kanamycin resistance ; β-glucuronidase ; gene expression ; potato
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Various aspects of a microprotoplast fusion technique and the strategies followed for intergeneric partial genome transfer (one or a few chromosomes) and alien genes from sexually-incongruent donor species to recipient species are described. The essential requirements of the microprotoplast fusion technique are the induction of micronuclei at high frequencies, as well as the isolation and enrichment of sub-diploid microprotoplasts in donor species, efficient fusion of the donor microprotoplasts with normal recipient protoplasts and stable regeneration of plants from fusion products. The results on the production of microprotoplast hybrid plants between the transformed donor lines of Solanum tuberosum and Nicotiana Plumbaginifolia carrying various genetic markers, and a recipient line of Lycopersicon peruvianum or Nicotiana tabacum, and on the transfer and expression of alien genes (kanamycin resistance, β-glucuronidase) are presented. The data obtained on microprotoplast hybrid plants between S. tuberosum and L. peruvianum showed that many of the hybrids contained one potato chromosome carrying nptII and GUS, and 24 or 48 L. peruvianum chromosomes (monosomic additions), and that they were male-and female-fertile. Various applications of chromosome transfer by this technique, especially for economically-important traits (e.g. disease or stress resistance) from sexually-incompatible wild species, for construction of chromosome-specific DNA libraries through microdissection and microcloning of chromosomes, or by flow-sorting of chromosomes for genome analysis, are discussed.
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  • 87
    ISSN: 1573-5060
    Keywords: Agrobacterium ; Brassica napus ; CaMV 35S promoter ; mas promoter ; gene expression ; risk assessment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Gene fusions between the β-glucuronidase (GUS) reporter gene and the promoters of the cauliflower mosaic virus 35S RNA transcript (CaMV 35S) and the mannopine synthase (mas) genes were introduced into rapeseed varieties via Agrobacterium-mediated transformation. Fluorometric assay of β-glucuronidase activity indicated different expression patterns for the two promoters. In seedlings, the CaMV 35S promoter had maximum activity in the primary roots, while the mas promoter was most active in the cotyledons. Etiolated seedlings cultured in the dark showed reduced activity of the mas promoter. Before vernalization at the rosette stage, both promoters were more active in older plant parts than in younger ones. At this stage the highest activity was recorded in cotyledons. After the plants had bolted reduced promoter function was detected in the upper parts of the transformed plants. Both promoters were found to be functional in the majority of the studied organs of transgenic rapeseed plants, but the promoter activity varied considerably between the organs at different developmental stages. The ability of pollen to transfer the introduced genes to other varieties and related species (e.g. Brassica napus and Diplotaxus muralis) by cross-pollination was studied in greenhouse experiments, and field trials were carried out to estimate the distance for biologically-relevant gene dispersal. In artificial crossing, the introduced marker gene was transferable into other varieties of Brassica napus. In field trials, at a distance of 1 metre from the source of transgenic plants, the frequency of an outcrossing event was relatively high (10-3). Resistant individuals were found at 16 and 32 metres from the transgenic pollen donors, but the frequency of an outcrossing event dropped to 10-5.
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  • 88
    ISSN: 1573-5060
    Keywords: carotenoids ; ethylene ; gene expression ; Lycopersicon esculentum Mill. ; polygalacturonase ; pectinesterase ; phytoene synthase ; ACC oxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The common cultivated tomato (Lycopersicon esculentum Mill.) provides a major focus for improvement of crop quality through genetic engineering. Identification of ripening-related cDNAs has enabled the modification of specific aspects of ripening by manipulating gene expression in transgenic plants. By utilizing ‘antisense RNA’ to modify expression of ripening genes, we have inhibited the production of the cell wall-metabolising enzymes polygalacturonase and pectinesterase and created transgenic plants that contain, effectively, single, targeted mutations affecting these genes. Furthermore, this approach has been used with previously unidentified cDNA clones to enable both functional identification and manipulation of genes involved in ethylene production (ACC oxidase) and carotenoid biosynthesis (phytoene synthase). The use of antisense RNA targeted to specific genes to alter ripening phenotypes and improve commercial utility of fruit by affecting shelf-life, processing characteristics and nutritional content is discussed. We have used the extreme ripening-impaired mutant, ripening inhibitor (rin) to identify additional genes implicated in the ripening process. This approach has resulted in the cloning of several novel ripening-related mRNAs which are now being studied by antisense experiments. This may enable identification and manipulation of additional genes involved in processes such as softening, flavour and aroma generation and susceptibility to pathogens.
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  • 89
    ISSN: 1573-5060
    Keywords: Vicia narbonensis ; gene transfer ; gene expression ; seeds ; 2S albumin ; methionine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Epicotyl explants were co-cultivated with Agrobacterium tumefaciens EHA101 to transfer a chimeric 2S albumin gene construct carried in the binary Ti plasmid vectors pGSGLUC1 or pGA472 into the grain legume Vicia narbonensis. This gene encoding the sulphur-rich Brazil nut albumin was under the control of either the CaMV 35S promoter which permits gene expression in all organs, or the Vicia faba legumin B4 promoter which elicits seed-specific gene expression. After callus formation and selection for kanamycin resistance, somatic embryos were induced which, in the case of transformation with the vector pGSGLUC1, were screened for GUS activity. Embryos that produced GUS were in addition analysed for 2S albumin formation. Selected transgenic embryos were cloned by multiple shoot regeneration. Rooted and fertile plants were obtained by grafting transgenic shoots on the appropriate seedlings. R1 and R2 generations were raised and analysed for GUS as well as 2S albumin gene expression. Expression of the 35S promoter/2S albumin gene fusion took place in all organs of the transgenic plants including the cotyledons of seeds, whereas seed-specific gene expression was found in transformants with the legumin promoter/2S albumin gene fusion. The 2S albumin accumulated in the 2S protein fraction of transgenic seeds and its primary translation product was processed into the 9 and 3 kDa polypeptide chains. The foreign protein was localised in the protein bodies of the grain legume. Analysis of the R2 plants indicated Mendelian inheritance of the 2S albumin gene. In homozygous V. narbonensis plants the amounts of 2S albumin were twice that present in the corresponding heterozygous plants. Whereas only low level formation of the foreign protein was achieved if the gene was under the control of the 35S promoter, approximately 3.0% of the soluble seed protein was 2S albumin if seed-specific gene expression was directed by the legumin B4 promoter. Some of these transformants exhibited a three-fold increase in the methionine content of the salt-soluble protein fraction extracted from seeds.
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