@article{GoebelChakrabortyKreft1988,
author = {Goebel, Werner and Chakraborty, T. and Kreft, J{\"u}rgen},
title = {Bacterial hemolysins as virulence factors},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60553},
year = {1988},
abstract = {No abstract available},
subject = {Biologie},
language = {en}
}
@article{GoebelKathariouKuhnetal.1988,
author = {Goebel, Werner and Kathariou, S. and Kuhn, M. and Sokolovic, Z. and Kreft, J{\"u}rgen and K{\"o}hler, S. and Funke, D. and Chakraborty, T. and Leimeister-W{\"a}chter, M.},
title = {Hemolysin from Listeria-biochemistry, genetics and function in pathogenesis},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60563},
year = {1988},
abstract = {No abstract available},
subject = {Biologie},
language = {en}
}
@article{ThiryScheerGoessens1988,
author = {Thiry, Marc and Scheer, Ulrich and Goessens, Guy},
title = {Immunoelectron microscopic study of nucleolar DNA during mitosis in Ehrlich tumour cells},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40745},
year = {1988},
abstract = {In order to investigate the DNA localization within Ehrlich tumor cell nucleoli during mitosis, two recent immunocytochemical methods using either an anti-DNA or an anti-bromodeoxyuridine (BrdU) monoclonal antibody have been applied. In both cases, the immunogold labeling has been performed on ultrathin sections of cells embedded either in Lowicryl K4M or in Epon, respectively. Identical results are observed with both immunocytochemical approaches. In the interphase nucleolus, besides the labeling of the perinucleolar chromatin shell and of its intranucleolar invaginations which penetrate into the nucleolar body and often terminate at the fibrillar centers, a few gold particles are also preferentially found towards the peripheral region of the fibrillar centers. In contrast, the dense fibrillar component and the granular component are never labeled. During mitosis, the fibrillar centers persist at the chromosomal nucleolus organizing regions (NOR's) and can be selectively stained by the silver method. However, these metaphase fibrillar centers are no longer decorated by the DNA- or BrdU antibodies. These results indicate that until the end of prophase, rRNA genes are present inside the fibrillar center material, disappear during metaphase and reappear in reconstituting nucleoli during telophase. Thus, fibrillar centers appear to represent structures sui generis, which are populated by rRNA genes only when the nucleolus is functionally active. In segregated nucleoli after actinomycin D treatment, the DNA labeling is exclusively restricted to the perinucleolar chromatin blocks. These findings also suggest that the DNA content of the fibrillar center material varies according to the rRNA transcription level of the cells. The results are discussed in the light of the present knowledge of the functional organization of the nucleolus.},
subject = {Cytologie},
language = {en}
}
@article{RoseSzopaHanetal.1988,
author = {Rose, Kathleen M. and Szopa, Jan and Han, Fu-Sheng and Cheng, Yung-Chi and Richter, Arndt and Scheer, Ulrich},
title = {Association of DNA topoisomerase I and RNA polymerase I: A possible role for topoisomerase I in ribosomal gene transcription},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33901},
year = {1988},
abstract = {RNA polymerase I preparations purified from a rat hepatoma contained DNA topoisomerase activity. The DNA topoisomerase associated with the polymerase had an Mr of 110000, required Mg2+ but not ATP, and was recognized by anti-topoisomerase I antibodies. When added to RNA polymerase I preparations containing topoisomerase activity, anti-topoisomerase I antibodies were able to inhibit the DNA relaxing activity of the preparation as well as RNA synthesis in vitro. RNA polymerase II prepared by analogous procedures did not contain topoisomerase activity and was not recognized by the antibodies. The topoisomerase I: polymerase I complex was reversibly dissociated by column chromatography on Sephacryl S200 in the presence of 0.25 M (NH4hS04. Topoisomerase I was immunolocalized in the transcriptionally active ribosomal gene complex containing RNA polymerase I in situ. These data indicate that topoisomerase I and RNA polymerase I are tightly complexed both in vivo and in vitro, and suggest a role for DNA topoisomerase I in the transcription of ribosomal genes.},
language = {en}
}
@article{ReimerRaskaScheeretal.1988,
author = {Reimer, Georg and Raska, Ivan and Scheer, Ulrich and Tan, Eng M.},
title = {Immunolocalization of 7-2-ribonucleoprotein in the granular component of the nucleolus},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33890},
year = {1988},
abstract = {Certain autoimmune sera contain antibodies against a nucleolar ribonucleoprotein particle associated with 7-2-RNA (R. Reddy et al. (1983) J. Bioi. Chem . 258, 1383; C. Hashimoto and J. A. Steitz (1983) J. Bioi. Chem. 258, 1379). In this study, we showed by immunofluorescence microscopy that antibodies reactive with 7-2-ribonucleoprotein immunolocalized in the granular regions of actinomycin D and 5,6-dichloro-I-j3-D-ribofuranosylbenzimidazole (DRB)-segregated nucleoli from Vero cells. By electron microscopic immunocytochemistry, antigen-antibody complexes were located in the granular component of transcriptionally active nucleoli from rat liver hepatocytes and HeLa cells. Anti-7- 2-RNP antibodies from two autoimmune sera immunoprecipitated a major protein of Mr 40,000 from e5S] methionine-Iabeled HeLa cell extract. The immunolocalization data suggest that 7-2-ribonucleoprotein may be involved in stages of ribosome biogenesis which take place in the granular component of the nucleolus, i.e., assembly, maturation, and/or transport of preribosomes},
language = {en}
}
@article{BenaventeSchmidtZachmannHuegleDoerretal.1988,
author = {Benavente, Ricardo and Schmidt-Zachmann, Marion S. and H{\"u}gle-D{\"o}rr, B. and Reimer, G. and Rose, K. M. and Scheer, Ulrich},
title = {Identification and definition of nucleolus-related fibrillar bodies in micronucleated cells},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-39423},
year = {1988},
abstract = {Small nucleolus-related bodies which occur in the nUcleoplasm of " micronuclei" lacking nucleolar organizers have been studied by immunofluorescence microscopy. These bodies stained specifically with three different antibodies directed against proteins that are normally associated with the dense fibrillar component of functional nucleoli, but not with antibodies specific for certain proteins of the granular component or the fibrillar centers. Our data show that, in the absence of rRNA genes, the various constituent proteins characteristic of the dense fibrillar component spontaneously assemble into spherical entities but that the subsequent fusion of these bodies into larger structures is prevented in these micronuclei. The similarity between these nucleolus-related bodies of micronuclei and the prenucleolar bodies characteristic of early stages of nucleologenesis during mitotic telophase is discussed.},
language = {en}
}
@article{ThiryScheerGoessens1988,
author = {Thiry, Marc and Scheer, Ulrich and Goessens, Guy},
title = {Localization of DNA within Ehrlich tumour cells nucleoli by immunoelectron microscopy},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-39327},
year = {1988},
abstract = {The distribution of DNA in Ehrlich tumour cell nucleoli was investigated by means of an immunocytochemical approach , involving a monoclonal antibody directed against double- and single-stranded DNA. Immunolabelling was performed . either before or after the embedding process. The postembedding labelling method allows better ultrastructural preservation than the preembedding labelling method. In particular, the various nucleolar components are well preserved and identifiable. In the nucleolus, labelling is particularly concentrated over the perinucleolar chromatin and over its intranucleolar invaginations, which penetrate the nucleolar body and often terminate at the fibrillar centres. In addition, aggregates of gold particles are found in the fibrillar centres, preferentially towards the peripheral regions. By contrast, the dense fibrillar component is completely devoid of labelling. The results seem to indicate that DNA containing the rDNA genes is located in the fibrillar centres, with a preference for the peripheral regions. This finding suggests that transcription of the rDNA genes should occur within the confines of the fibrillar centre, probably close to the boundary region of the surrounding dense fibrillar component. The results are discussed in the light of present knowledge of the functional organization of the nucleolus.},
language = {en}
}
@article{GeiseLinsenmair1988,
author = {Geise, W. and Linsenmair, Karl Eduard},
title = {Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment. IV. Ecological significance of water economy with comments on thermoregulation and energy allocation},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30570},
year = {1988},
abstract = {No abstract available},
language = {en}
}
@article{DabauvalleSchulzScheeretal.1988,
author = {Dabauvalle, Marie-Christine and Schulz, Barbara and Scheer, Ulrich and Peters, Reiner},
title = {Inhibition of nuclear accumulation of karyophilic proteins in living cells by microinjection of the lectin wheat germ agglutinin},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34288},
year = {1988},
abstract = {No abstract available},
language = {en}
}
@article{ScheerDabauvalleMerkertetal.1988,
author = {Scheer, Ulrich and Dabauvalle, Marie-Christine and Merkert, Hilde and Benavente, Ricardo},
title = {The nuclear envelope and the organization of the pore complexes},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34275},
year = {1988},
abstract = {No abstract available},
language = {en}
}
@article{LinsenmairSchmuck1988,
author = {Linsenmair, Karl Eduard and Schmuck, R.},
title = {Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment. III. Aspects of nitrogen metabolism and osmuregulation in the reed frog, H. viridiflavus taeniatus, with special reference to the role of iridophores},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78108},
year = {1988},
abstract = {Reed frogs of the superspecies Hyperolius viridiflavus occur throughout the seasonally very dry and hot African savannas. Despite their small size (300-700 mg), estivating reed frogs do not avoid stressful conditions above ground by burrowing into the soil, but endure the inhospitable climate relatively unprotected, clinging to mostly dry grass sterns. They must have emcient mechanisms to enable them to survive e.g. very high temperatures, low relative hurnidities, and high solar radiation loads. Mechanisms must also have developed to prevent poisoning by the nitrogenous wastes that inevitably result from protein and nucleotide turnover. In contrast to fossorial amphibians, estivating reed frogs do not become torpid. Reduction in metabolism is therefore rather Iimited so that nitrogenous wastes accumulate faster in these frogs than in fossorial amphibians. This severely aggravates the osmotic problems caused by dehydration. During dry periods total plasma osmolarity greatly increases, mainly due to urea accumulation. Of the total urea accumulated over 42 days of experimental water deprivation, 30\% was produced during the first 7 days. In the next 7 days rise in plasma urea content was negligible. This strong initial increase of urea is seen as a byproduct of elevated amino acid catabolism following the onset of dry conditions. Tbe rise in total plasma osmolarity due to urea accumulation, however, is not totally disadvantageous, but enables fast rehydration when water is available for very short periods only. Voiding of urine and feces eeases once evaporative water loss exceeds 10\% of body weight. Tberefore, during continuous water deprivation, nitrogenous end products are not excreted. After 42 days of water deprivation, bladder fluid was substantially depleted, and urea coneentration in the remaining urine (up to 447 mM) was never greater than in plasma fluid. Feces voided at the end of the dry period after water uptake contained only small amounts of nitrogenous end products. DSF (dry season frogs) seemed not to be uricotelic. Instead, up to 35\% of the total nitrogenous wastes produced over 42 days of water deprivation were deposited in an osmotically inert and nontoxic form in iridophore crystals. The increase in skin purine content averaged 150 µg/mg dry weight. If urea had been the only nitrogenous waste product during an estivation period of 42 days, lethal limits of total osmolarity (about 700 mOsm) would have been reached 10-14 days earlier. Thus iridophores are not only involved in colour change and in reducing heat load by radiation remission, but are also important in osmoregulation during dry periods. The seIective advantages of deposition of guanine rather than uric acid are discussed.},
subject = {Biologie},
language = {en}
}
@article{SchmuckKobeltLinsenmair1988,
author = {Schmuck, R. and Kobelt, F. and Linsenmair, Karl Eduard},
title = {Adaptations of the reed frog Hyperbolius viridiflavus (Anura, Hyperbolidae) to its arid environment: V. Iridophores and nitrogen metabolism},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78094},
year = {1988},
abstract = {Ofall amphibians living in arid habitats, reed frogs (belonging to the super species Hyperolius viridiflavus) are the most peculiar. Froglets are able to tolerate dry periods of up to 35 days or longer immediately after metamorphosis, in climatically exposed positions. They face similar problems to estivating juveniles, i.e. enduranee of long periods of high temperature and low RH with rather limited energy and water reserves. In addition, they must have had to develop meehanisms to prevent poisoning by nitrogenous wastes that rapidly accumulate during dry periods as a metabolie consequenee of maintaining a non-torpid state. During dry periods, plasma osmolarity of H. v. taeniatus froglets strongly increased, mainly through urea accumulation. Urea accumulation was also observed during metamorphic climax. During postmetamorphic growth, chromatophores develop with the density and morphology typical of the adult pigmentary pattern. The dermal iridophore layer, which is still incomplete at this time, is fully developed within 4-8 days after metamorphosis, irrespective of maintenance conditions. These iridophores mainly contain the purines guanine and hypoxanthine. The ability of these purines to reflect light provides an excellent basis for the role of iridophores in temperature regulation. In individuals experiencing dehydration stress, the initial rate of purine synthesis is doubled in eomparison to specimens continuously maintained under wet season conditions. This increase in synthesis rate leads to a rapid increase in the thiekness of the iridophore layer, thereby effectively reducing radiation absorption. Thus, the danger of overheating is diminished during periods of water shortage when evaporative cooling must be avoided. After the development of an iridophore layer of sufficient thickness for effective radiation reflectance, synthesis of iridophore pigments does not cease. Rather, this pathway is further used during the remaining dry season for solving osmotic problems eaused by accumulation of nitrogenous wastes. During prolonged water deprivation, in spite of reduced metabolic rates, purine pigments are produced at the same rate as in wet season conditions. This leads to a higher relative proportion of nitrogen end products being stored in skin pigments under dry season conditions. At the end of an experimental dry season lasting 35 days, up to 38\% of the accrued nitrogen is stored in the form of osmotically inactive purines in thc skin. Thus the osmotic problems caused by evaporative water loss and urea production are greatly reduced.},
subject = {Biologie},
language = {en}
}
@article{MaeuelerRaulfSchartl1988,
author = {M{\"a}ueler, Winfried and Raulf, Friedrich and Schartl, Manfred},
title = {Expression of proto-oncogenes in embryonic, adult, and transformed tissue of Xiphophorus (Teleostei: Poeciliidae)},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86233},
year = {1988},
abstract = {In Xiphophorus the causative, primary cellular oncogene for melanoma formation has been assigned by classical genetics to a sex-chromosomal locus, designated Tu. Activation of Tu was proposed to be the result of the elimination of Tu-specific regulatory genes which normally suppress the transforming function in the nontumorous state. In order to understand the role which known proto-oncogenes migbt play in this process, we have analysed the expression of src, erb A, erb B, ras, abl, sis and mil related genes from Xiphophorus during embryogenesis, in non-tumorous organs and in melanoma cells. For src, ras, erb B and sis a differential expression during embryogenesis and/or in normal organs was detected, with preferential expression of src in neural tissues, a high abundance of sis transcripts in an embryonal epitheloid cellline and of erbB transcripts in the head nephros. In melanoma cells ras, src and a v-erb B related gene were found to be expressed. The src gene most likely is more involved in secondary processes during tumor progression, while the expression of the v-erb B related gene might be transformation-specific because recently such a sequence was found to map to the close vicinity of the Tu-locus.},
subject = {Schwertk{\"a}rpfling},
language = {en}
}
@article{MauelerBarnekowEigenbrodtetal.1988,
author = {Maueler, W. and Barnekow, A. and Eigenbrodt, E. and Raulf, F. and Falk, H. F. and Telling, A. and Schartl, Manfred},
title = {Different regulation of oncogene expression in tumor and embryonal cells of Xiphophorus},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86240},
year = {1988},
abstract = {Melanoma formation in the poeciliid fish Xiphophorus is mediated primarily by a cellular oncogene, designated Tu. Elimination of Tu-specific genes releases the transforming function of Tu and leads to melanoma formation. Southern blot analyses revealed a tight linkage of a v-erb B related gene to the Tu-locus and Northern blot analyses of RNA of solid melanomas indicated a coordinated deregulation and for mutational activation of several oncogenes. In order to get a better insight into the regulation of oncogene expression in normal and transformed cells of Xiphophorus, we studied the expression of Xsrc, Xras, Xmyc, Xerb A, Xsis, and the v-erb B related gene in a melanoma derived cell line (PSM) and an embryonic cell line (A2) under conditions of low growth factor supply. Both celllines express the Xsrc, Xmyc, and Xras genes, while PSM cells in addition express the v-erb B related gene and A2 cells the Xsis gene. In PSM cells serum deprivation leads to an accumulation of most of the oncogene mRNAs analysed. This is most apparent for a 5.0 kb transcript of the v-erb B related gene, probably due to an increase in transcript stability. The levels of these mRNAs returned to normal within 2h after stimulation with 10\% fetal calf serum. At the protein level we observed an initial decrease followed by an increase of the n-p60c-src kinase (the protein product of tbe Xsrc gene) activity in cells deprived of serum. Serum stimulation restored a normal pp60"-src kinase activity. In contrast serum deprivation of A2 cells reduced the transcript amounts of each of the oncogenes analysed. The same holds true for one beta-tubulin transcript, while the level of a second beta-tubulin transcript was unaffected. Serum stimulation led to a reactivation of Xras and Xsrc after a delay of approximately 48b. The pp60(c-src) kinase activity was found to be 6-10 times lower as compared to the PSM cells and did not differ between serum deprived and serum stimulated cells. Enzyme activities and isoenzyme patterns of several glycolytic enzymes were found to be not affected by serum deprivation and stimulation in both celllines.},
subject = {Schwertk{\"a}rpfling},
language = {en}
}
@article{BenaventeReimerRoseetal.1988,
author = {Benavente, Ricardo and Reimer, Georg and Rose, Kathleen M. and H{\"u}gle-D{\"o}rr, Barbara and Scheer, Ulrich},
title = {Nucleolar changes after microinjection of antibodies to RNA polymerase I into the nucleus of mammalian cells},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40666},
year = {1988},
abstract = {After microinjection of antibodies against RNA polymerase I into the nuclei of cultured rat kangaroo (PtKz) and rat (RVF-SMC) cells alterations in nucleolar structure and composition were observed. These were detected by electron microscopy and double-label immunofluorescence microscopy using antibodies to proteins representative of the three major components of the nucleolus. The microinjected antibodies produced a progressive loss of the material of the dense fibrillar component (DFC) from the nucleoli which, at 4 h after injection, were transformed into bodies with purely granular component (GC) structure with attached fibrillar centers (FCs). Concomitantly, numerous extranucleolar aggregates appeared in the nucleoplasm which morphologically resembled fragments of the DFC and contained a protein (fibrillarin) diagnostic for this nucleolar structure. These observations indicate that the topological distribution of the material constituting the DFC can be experimentally influenced in interphase cells, apparently by modulating the transcriptional activity of the rRNA genes. These effects are different from nucleolar lesions induced by inhibitory drugs such as actinomycin D-dependent "nucleolar segregation". The structural alterations induced by antibodies to RNA polymerase I resemble, however, the initial events of nucleolar disintegration during mitotic prophase.},
language = {en}
}
@article{RaulfRobertsonSchartl1989,
author = {Raulf, F. and Robertson, S. M. and Schartl, Manfred},
title = {Evolution of the neuron-specific alternative splicing product of the c-src proto-oncogene},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61796},
year = {1989},
abstract = {The observation of a slower migrating form of pp6oc-src in neural tissue of chicken and mouse has recently been shown to be due to an alternative transcript form of tbe c-src gene (Martinez et al.: Science 237:411-415, 1987; Levy et al.: Mol Cell Bio17:4142- 4145, 1987). An insertion of 18 basepairs between exons 3 and 4, presumed to be due to alternative splicing of a mini-exon, gives rise to six amino acid residues not found in the non-neuronal (termed flbroblastic) form of pp60\(^{c-src}\). Wehave addressed the question of the evolutionary origin of the c-src neuronal insert · and its functional signiflcance regarding neural-speciflc expression of the c-src gene. To this end we have investigated whether the c-src gene of a lower verlebrate (the teleost fish Xiphophorus) gives rise to a neural-specific transcript in an analogous manner. We could show that the fish c-src gene does encode for a "fibroblastic" and a "neuronal" form of transcript and that the neuronal transcript does indeed arise by way of alternative splicing of a mini-exon. The miniexon is also 18 basepairs long and we could demoostrate directly that this exon lies within the intron separating exons 3 and 4. For comparative purposes we have examined whether the fish c-yes gene, the member of the src gene family most closely related to c-src, also encodes a neural tissue-specific transcript. No evidence for a second transcript form in brain was obtained. This result suggests that the mini-exon arose within the c-src gene lineage sometime between the srclyes gene duplication event and the divergence of the evolutionary lineage giving rise to the teleost fish. Published genomic sequence of src-related genes in Drosophila and our own results with Hydra demoostrate no intron in these species at the analogous location, consistent with first appearance of this mini-exon sometime between 550 and 400 million years ago.},
subject = {Physiologische Chemie},
language = {en}
}
@article{WittbrodtAdamMalitscheketal.1989,
author = {Wittbrodt, J. and Adam, D. and Malitschek, B. and Maueler, W. and Raulf, F. and Telling, A. and Robertson, M. and Schartl, Manfred},
title = {Novel putative receptor tyrosine kinase encoded by the melanoma-inducing Tu locus in Xiphophorus},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61800},
year = {1989},
abstract = {No abstract available},
subject = {Physiologische Chemie},
language = {en}
}
@article{BernardsSchacklefordGerberetal.1989,
author = {Bernards, R. and Schackleford, G. M. and Gerber, M. R. and Horowitz, J. M. and Friend, S. H. and Schartl, Manfred and Bogenmann, E. and Rapaport, J. M. and Mcgee, T. and Dryja, T. P.},
title = {Structure and expression of the murine retinoblastoma gene and characterization of its encoded protein},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61819},
year = {1989},
abstract = {No abstract available},
subject = {Physiologische Chemie},
language = {en}
}
@article{WeigelMeyerSebald1989,
author = {Weigel, U. and Meyer, M. and Sebald, Walter},
title = {Mutant proteins of human interleukin 2. Renaturation yield, proliferative activity and receptor binding},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62543},
year = {1989},
abstract = {No abstract available},
subject = {Biochemie},
language = {en}
}
@article{FlueggeFischerGrossetal.1989,
author = {Fl{\"u}gge, U. I. and Fischer, K. and Gross, A. and Sebald, Walter and Lottspeich, F. and Eckerskorn, C.},
title = {The triose phosphate-3-phosphoglycerate-phosphate translocator from spinach chloroplasts: nucleotide sequence of a full-length cDNA clone and import of the in vitro synthesized precursor protein into chloroplasts},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62559},
year = {1989},
abstract = {No abstract available},
subject = {Biochemie},
language = {en}
}
@article{KreftFunkeSchlesingeretal.1989,
author = {Kreft, J{\"u}rgen and Funke, D. and Schlesinger, R. and Lottspeich, F. and Goebel, Werner},
title = {Purification and characterization of cytolysins from Listeria monocytogenes serovar 4b and Listeria ivanovii},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47036},
year = {1989},
abstract = {Several exoproteins from Listeria monocytogenes serovar 4b (NCTC 10527) and Listeria ivanovii (ATCC) 19119, SLCC 2379), respectively, have been purified to homogeneity by thiol-disulfide exchange chromatography and gel filtration. Both strains produce a haemolytic/cytolytic protein of Mr 58 kDa, which has all the properties of a SH-activated cytolysin, the prototype of which is streptolysin 0 (SLO), and this protein has therefore heen termed Iisteriolysin 0 (LLO). In addition a protein of Mr 24 kDa from culture supernatants of L. ivanovii co-purified withLLO. The N-terminal aminoacid sequences of both proteins from L. ivanovii have been determined. By mutagenesis with transposons of Gram-positive origin (Tn916 and TnI545), which have been introduced via conjugation into L. ivanovii, several phenotypic mutants (altered haemolysis on sheep blood agar or lecithinase-negative) were obtained. Results on the properties of these muntants will he presented.},
language = {en}
}
@article{KreftHaasGoebel1989,
author = {Kreft, J{\"u}rgen and Haas, Albert and Goebel, Werner},
title = {Isolation and characterization of genes coding for proteins involved in the cytolysis by Listeria ivanovii},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-46991},
year = {1989},
abstract = {We established a library of chromosomal DNA of Listeria ivanovii in the pTZ19R plasmid system, using Escherichia coli DH5alpha as the host. One recombinant clone reacted strongly with a polyclonal antiserum raised against the listeriolysin 0 and a second exoprotein (24kDa) of L. ivanovii, which is most probably also involved in cytolytic processes. The recombinant E. coli clone may contain part of the listeriolysin 0 gene of L. ivanovii.},
language = {en}
}
@article{GesslerBruns1989,
author = {Gessler, Manfred and Bruns, G. A. P.},
title = {A physical map around the WAGR complex on the short arm of chromosome 11},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59246},
year = {1989},
abstract = {A long-range restriction map of part of the short arm of ehromosome 11 including the WAGR region has been constructed using pulsed-field gel electrophoresis and a number of infrequently cutting restriction enzymes. A total of 15.4 Mbp has been mapped in detall, extending from proximal 11p14 to the distal part of 11p12. The map localizes 35 different DNA probes and reveals at least nine areas with features eharaeteristle of BTF islands, some of which may be candidates for the different loci underlying the phenotype of the WAGR syndrome. This map will furthermore allow screening of DNA from individuals with WAGR-related phenotypes and from Wilms tumors for associated chromosomal rearrangements.},
subject = {Biochemie},
language = {en}
}
@article{GesslerThomasCouillinetal.1989,
author = {Gessler, Manfred and Thomas, G. H. and Couillin, P. and Junien, C. and McGillivray, B. C. and Hayden, M. and Jaschek, G. and Bruns, G. A.},
title = {A deletion map of the WAGR region on chromosome II},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59255},
year = {1989},
abstract = {The WAGR (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) region has been assigned to chromosome 11p13 on the basis of overlapping constitutional deletions found in affected individuals. We have utilized 31 DNA probes which map to the WAGR deletion region, together with six reference loci and 13 WAGR-related deletions, to subdivide this area into 16 intervals. Specific intervals have been correlated with phenotypic features, leading to the identification of individual subregions for the aniridia and Wilms tumor loci. Delineation, by specific probes, of multiple intervals above and below the critical region and of five intervals within the overlap area provides a framework map for molecular characterization of WAGR gene loci and of deletion boundary regions.},
subject = {Biochemie},
language = {en}
}
@article{KreftFunkeHaasetal.1989,
author = {Kreft, J{\"u}rgen and Funke, Dorothee and Haas, Albert and Lottspeich, Friedrich and Goebel, Werner},
title = {Production, purification and characterization of hemolysins from Listeria ivanovii and Listeria monocytogenes Sv4b.},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60545},
year = {1989},
abstract = {In culture supematants of both Listeria ivanovii and Listeria monocytogenes Sv4b, for the first time a hemolysin of molecular weight 58 kDa was identified, which had all the characteristics of an SH-activated cytolysin, and which was therefore identified as Iisteriolysin 0 (LLO). In the case of L. ivanovii a second major supematant protein of molecular weight 24 kDa co-purified with LLO. However, the function of this protein has to be determined. In culture supematants of L. ivanovii a sphingomyelinase and a Iecithinase activity could be detected, both enzymatic activities together contributing to the pronounced hemolysis caused by L. ivanovii. The N-tenninal amino acid sequences of LLO and the 24 kDa from L. ivanovii are shown.},
subject = {Biologie},
language = {en}
}
@article{GilmoreCruzRodzLeimeisterWaechteretal.1989,
author = {Gilmore, Michael S. and Cruz-Rodz, Armando L. and Leimeister-W{\"a}chter, Michaela and Kreft, J{\"u}rgen and Goebel, Werner},
title = {A Bacillus cereus cytolytic determinant, cereolysin AB, which comprises the phospholipase C and sphingomyelinase genes: nucleotide sequence and genetic linkage},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60588},
year = {1989},
abstract = {A cloned cytolytic determinant from the genome of Bacillus cereus GP-4 has been characterized at the molecular Ievel. Nucleotide sequence determination revealed the presence of two open reading frames. 8oth open reading frames were found by deletion and complementation analysis to be necessary for expression of the hemolytic phenotype by Bacillus subtilis and Escherichia coli hosts. The 5' open reading frame was found to be nearly identical to a recently reported phospholipase C gene derived from a mutant B. cereus strain which overexpresses the respective protein, and it conferred a lecithinase-positive phenotype to the B. subtilis host. The 3' open reading frame encoded a sphingomyelinase. The two tandemly encoded activities, phospholipase C and sphingomyelinase, constitute a biologically functional cytolytic determinant of B. cereus termed cereolysin AB.},
subject = {Biologie},
language = {en}
}
@article{BenaventeDabauvalleScheeretal.1989,
author = {Benavente, Ricardo and Dabauvalle, Marie-Christine and Scheer, Ulrich and Chaly, Nathalie},
title = {Functional role of newly formed pore complexes in postmitotic nuclear reorganization},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40754},
year = {1989},
abstract = {Many nuclear proteins are released into the cytoplasm at prometaphase and are transported back into the daughter nuclei at the end of mitosis. To determine the role of this reentry in nuclear remodelling during early interphase, we experimentally manipulated nuclear protein uptake in dividing cells. Recently we and others have shown that signal-dependent, pore complex-mediated uptake of nuclear protein is blocked in living cells on microinjection of the lectin wheat germ agglutinin (WGA), or of antibodies such as PI1 that are directed against WGA-binding pore complex glycoproteins. In the present study, we microinjected mitotic PtKz cells with WGA or antibody PIt and followed nuclear reorganization of the daughter cells by immunofluorescence and electron microscopy. The inhibitory effect on nuclear protein uptake was monitored by co-injection of the karyophilic protein nucleoplasmin. When injected by itself early in mitosis, nucleoplasmin became sequestered into the daughter nuclei as they entered telophase. In contrast, nucleoplasmin was excluded from the daughter nuclei in the presence of WGA or antibody PI1 . Although PtKz cells with blocked nuclear protein uptake completed cytokinesis, their nuclei showed a telophaselike organization characterized by highly condensed chromatin surrounded by a nuclear envelope containing a few pore complexes. These findings suggest that pore complexes become functional as early as telophase, in close coincidence with nuclear envelope reformation. They further indicate that the extensive structural rearrangement of the nucleus during the telophase-G1 transition is dependent on the influx of karyophilic proteins from the cytoplasm through the pore complexes, and is not due solely to chromosome- associated components.},
language = {en}
}
@article{WeberSchmidtScheer1989,
author = {Weber, Thomas and Schmidt, Erwin and Scheer, Ulrich},
title = {Mapping of transcription units on Xenopus laevis lampbrush chromosomes by in situ hybridization with biotin-labeled cDNA probes},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40763},
year = {1989},
abstract = {A non-radioactive in situ hybridization method is described for the localization of transcription units of defined genes to lateral loops of Xenopus laevis lampbrush chromosomes. Two Xenopus cONA probes were used encoding the nucleolar protein N038/ B23 and cytokeratin 1(8). Both proteins are known to be synthesized in Xenopus oocytes, and Northern blot analysis revealed the presence of the corresponding mRNAs in different oogenic stages. The probes were enzymatically labeled with biotin-dCTP and hybridized to lampbrush chromosomes. The sites of hybridization were detected either by indirect immunofluorescence microscopy using rabbit antibodies against biotin and fluorescein-conjugated antirabbit IgG or enzymatically using peroxidase-conjugated streptavi din. The probe encoding the nucleolar protein hybridized to two sets of lateral loops on different bivalents, the cytokeratin probe to at least four. Our finding that each probe hybridized to more than one chromosomal locus may reflect the tetraploid nature of the Xenopus laevis genome or results from cross-hybridization to other transcriptionally active members of the N038/ B23-nucleoplasmin or the cytokeratin-Iamin gene families. The method described should facilitate further in situ hybridization studies with appropriate genomic clones in order to map specific DNA sequences to defined loop regions and to come to a better understanding of the relationship between loop organization and gene transcription unit.},
subject = {Cytologie},
language = {en}
}
@article{BenaventeScheerChaly1989,
author = {Benavente, Ricardo and Scheer, Ulrich and Chaly, Nathalie},
title = {Nucleocytoplasmic sorting of macromolecules following mitosis: fate of nuclear constituents after inhibition of pore complex function},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40777},
year = {1989},
abstract = {PtK2 cells in which pore complex-mediated transport is blocked by microinjection early in mitosis of a monoclonal antibody (specific for an Mr 68000 pore complex glycoprotein) or of wheat germ agglutinin (WGA) complete cytokinesis. However, their nuclei remain stably arrested in a telophase-like organization characterized by highly condensed chromatin and the absence of nucleoli, indicating a requirement for pore-mediated transport for the reassembly of interphase nuclei. We have now examined this requirement more closely by monitoring the behavior of individual nuclear macromolecules in microinjected cells using immunofluorescence microscopy and have investigated the effect of microinjecting the antibody or WGA on cellular ultrastructure. The absence of nuclear transport did not affect the sequestration into daughter nuclei of components such as DNA, DNA topoisomerase I and the nucleolar protein fibrillarin that are carried through mitosis on chromosomes. On the other hand, lamins, snRNAs and the p68 pore complex glycoprotein, all cytoplasmic during mitosis, remained largely cytoplasmic in the telophase-arrested cells. Electron microscopy showed the nuclei to be surrounded by a doublelayered membrane with some inserted pore complexes. In addition, however, a variety of membranous structures with associated pore complexes was regularly noted in the cytoplasm, suggesting that chromatin may not be essential for the postmitotic formation of pore complexes. We propose that cellular compartmentalization at telophase is a two-step process. First, a nuclear envelope tightly encloses the condensed chromosomes, excluding non-selectively all macromolecules not associated with the chromosomes. Interphase nuclear organization is then progressively restored by selective pore complex-mediated uptake of nuclear proteins from the cytoplasm.},
subject = {Cytologie},
language = {en}
}
@article{MaschwitzFialaLeeetal.1989,
author = {Maschwitz, Ulich and Fiala, Brigitte and Lee, Ying Fah and Chey, Vun Khen and Tan, Fui Lian},
title = {New and little-known myrmecophytic associations from Bornean rain forests},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42957},
year = {1989},
abstract = {The woody climber Millettia niuewenhuisii (Fabaceae) and the shrub Myrmeconauclea strigosa (Rubiaceae) in Sabah, Borneo are associated with ants. The hollow stems of Millettia nieuwenhuisii are regularly inhabited by an aggressive Cladomyrma sp., which keeps pseudococcids inside the stem. On Myrmeconauclea strigosa the ants live in hollow internodal swellings near the end of the branches. In this plant many different ant species use the nesting space in an opportunistic manner.},
language = {en}
}
@article{FialaMaschwitzPongetal.1989,
author = {Fiala, Brigitte and Maschwitz, Ulrich and Pong, Tho, Yow and Helbig, Andreas J.},
title = {Studies of a South East Asian ant-plant association : protection of Macaranga trees by Crematogaster borneensis},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42857},
year = {1989},
abstract = {In the humid tropics of SE Asia there are some 14 myrmecophytic species of the pioneer tree genus Macaranga (Euphorbiaceae). In Peninsular Malaysia a close association exists between the trees and the small, non-stinging myrmicine Crema togas ter borneensis. These ants feed mainly on food bodies provided by the plants and have their colonies inside the hollow intemodes. In a ten months field study we were able to demonstrate for four Macaranga species (M. triloba, M. hypoleuca, M. hosei, M. hulletti) that host plants also benefit considerably from ant-occupation. Ants do not contribute to the nutrient demands of their host plant, they do, however, protect it against herbivores and plant competition. Cleaning behaviour of the ants results in the removal of potential herbivores already in their earliest developmental stages. Strong aggressiveness and a mass recruiting system enable the ants to defend the host plant against many herbivorous insects. This results in a significant decrease in leaf damage due to herbivores on ant-occupied compared to ant-free myrmecophytes as well as compared to non-myrmecophytic Macaranga species. Most important is the ants' defense of the host plant against plant competitors, especially vines, which are abundant in the well-lit pioneer habitats where Macaranga grows. Ants bite off any foreign plant part coming into contact with their host plant. Both ant-free myrmecophytes and non-myrmecophytic Macaranga species had a significantly higher incidence of vine growth than specimens with active ant colonies. This may be a factor of considerable importance allowing Macaranga plants to grow at sites of strongest competition.},
language = {en}
}
@article{DandekarRibesTollervey1989,
author = {Dandekar, Thomas and Ribes, V. and Tollervey, David},
title = {Schizosaccharomyces pombe U4 small nuclear RNA closely resembles vertebrate U4 and is required for growth},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29771},
year = {1989},
abstract = {No abstract available},
language = {en}
}
@article{DandekarTollervey1989,
author = {Dandekar, Thomas and Tollervey, David},
title = {Cloning of Schizosaccharomyces pombe genes encoding the U1,U2,U3 and U4 snRNAs},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29919},
year = {1989},
abstract = {No abstract available},
language = {en}
}
@article{GrafeLinsenmair1989,
author = {Grafe, U. and Linsenmair, Karl Eduard},
title = {Protogynous sex change in the Reed Frog: Hyperolius viridiflavus},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30990},
year = {1989},
abstract = {Observations on captive reed frogs Hyperolius viridijlavus ommatostictus showed that seven out of 24 females changed into males. Sex change occurred without any hormone treatment and resulted in completely functional males. The adaptive value is discussed in terms of maximizing life-time reproductive success. Hyperolius r. ommatostictus is the first amphibian known to show functional sex reversal.},
language = {en}
}
@article{RaulfMaeuelerRobertsonetal.1989,
author = {Raulf, Friedrich and M{\"a}ueler, Winfried and Robertson, Scott M. and Schartl, Manfred},
title = {Localization of cellular src mRNA during development and in the differentiated bipolar neurons of the adult neural retina in Xiphophorus},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86703},
year = {1989},
abstract = {The expression of the c-src gene in embryonie and adult tissue of the teleost fish Xiphophorus helleri was analyzed by in-situ hybridization. The highly conserved fish c-src gene was found to be expressed at high levels in midterm embryos, where c-src mRNA was localized in developing neurons of the sensory layer of the differentiating retina and in the developing brain. In adult tissues the expression of c-src was found to persist in certain cell types of the brain and the neural retina, especially in the bipolar cells of the inner nuclear layer, which are postmitotic, fully differentiated mature neurons. Thus c-src in Xiphophorus appears to be a developmentally regulated proto-oncogene which is important for neuronal differentiation during organogenesis, but whose persistence of expression in certain terminally differentiated neurons strongly suggests a particular maintenance function for c-src in these cells as well.},
subject = {Schwertk{\"a}rpfling},
language = {en}
}
@article{SchartlHolsteinRobertsonetal.1989,
author = {Schartl, Manfred and Holstein, Thomas and Robertson, Scott M. and Barnekow, Angelika},
title = {Preferential expression of a pp60c-src related protein tyrosine kinase activity in nerve cells of the early metazoan Hydra (Coelenterates)},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86179},
year = {1989},
abstract = {It has been suggested that the proto-oncogene c-src plays a functional role in developing neurons, and in the mature nerve cells of higher vertebrales. The coelenterate Hydra represents tbe most primitive known organism possessing nerve cells. With Southern blot hybridizations we have demonstrated src-related sequences in Hydra. Antisera specific for the c-src gene product (pp60 c-src) of birds and mammals precipitate a protein from Hydra cell extracts with a tyrosine-specific protein kinase activity. Studies of tissues and cells fractionated from a temperature sensitive mutant of Hydra which is depleted of interstitial (including nerve) cells at tbe non-permissive temperature, have indicated the src-like kinase of Hydra to be preferentially expressed in nerve cells. The high conservation of structural features and of the expression pattern indicates a basic function for pp60c-src in neurons.},
subject = {Protein-Tyrosin-Kinasen},
language = {en}
}
@article{MerzFliednerLehrnbecheretal.1990,
author = {Merz, H. and Fliedner, A. and Lehrnbecher, T. and Sebald, Walter and M{\"u}ller-Hermelink, H. K. and Feller, A. C.},
title = {Cytokine expression in B-cell non-Hodgkin lymphomas},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62539},
year = {1990},
abstract = {No abstract available},
subject = {Biochemie},
language = {en}
}
@article{Fiala1990,
author = {Fiala, Brigitte},
title = {B{\"a}ume \& Ameisen : Partnerschaften im s{\"u}dostasiatischen Regenwald},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-54741},
year = {1990},
abstract = {No abstract available},
subject = {Baum},
language = {de}
}
@article{Schartl1990,
author = {Schartl, Manfred},
title = {Homology of melanoma-inducing loci in the genus Xiphophorus},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61757},
year = {1990},
abstract = {Several species of the genus Xiphophorus are polymorphic for specific pigment patterns. Same of these give rise to malignant melanoma following the appropriate crossings. For one of these pattern Iod from the platyfish Xiphophorus maculatus the melanoma-inducing gene has been doned and found to encode a novel receptor tyrosine kinase, designated Xmrk. Using molecular probes from this gene in Southern blot analyses on single fish DNA preparations from 600 specimens of different populations of various species of the genus Xiphophorus and their hybrids, either with or without melanomapredisposing pattern, it was shown that all individuals contain the Xmrk gene as a proto-oncogene. It is located on the sex chromosome. All fish that carry a melanoma-predisposing locus which has been identified by Mendelian genetics contain an additional copy of Xmrk, closely linked to a specific melanophore pattern locus on the sex chromosome. The melanoma-inducing loci of the different species and populations are homologous. The additional copy of Xmrk obviously arose by a geneduplication event, thereby acquiring the oncogenic potential. The homology of the melanomainducing Iod points to a similar mechanism of tumor suppression in all feral fish populations of the different species of the genus Xiphophorus.},
subject = {Physiologische Chemie},
language = {en}
}
@article{DracopoliFeltquateSametal.1990,
author = {Dracopoli, Nicholas C. and Feltquate, David M. and Sam, Brigitta and Schartl, Manfred},
title = {Taql and Mspl RFLPs are detected by the human 2,3-biphosphoglycerate mutase (BPGM) cDNA},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61763},
year = {1990},
abstract = {No abstract available},
subject = {Physiologische Chemie},
language = {en}
}
@article{FriedenreichSchartl1990,
author = {Friedenreich, Hildegard and Schartl, Manfred},
title = {Transient expression directed by homologous and heterologous promoter and enhancer sequences in fish cells},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61774},
year = {1990},
abstract = {ln order to construct fish specific expression vectors for studies on gene regulation in vitro and in vivo a variety of heterologous enhancers and promoters from mammals and from viruses of higher vertebrate cells were tested for expression of the bacterial chloramphenicol acetyl transferase reporter gene in three teleost fish cell lines. Several viral enhancers were found to be constitutively active at high Ieveis. The human metallothionein promoter showed inducible expression in the presence of heavy metal Ions. A fish sequence was isolated that can be used as a homologous constitutively active promoter for expression of foreign genes. Using the human growth hormone gene with an active promoter in fish cells for transient expression insufficient splicing and Iack of translation were observed, pointing to limitations in the use of heterologous genes in gene transfer experiments. On the contrary, some heterologous promoters and enhancers functioned in fish c as weil as in their cell type of origin, indicating t at corresponding transcription factors are sufficient conserved between fish and human over a period of 900 million years of Independent evolution.},
subject = {Physiologische Chemie},
language = {en}
}
@article{ClaussWinklerLohmeyeretal.1990,
author = {Clauss, Gerd and Winkler, Christoph and Lohmeyer, J{\"u}rgen and Anders, Fritz and Schartl, Manfred},
title = {Oncofetal antigen in Xiphophorus detected by monoclonal antibodies directed against melanoma-associated antigens},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61784},
year = {1990},
abstract = {Monoclonal antlbodies (MAbs) directed against Xiphophorus melanoma cells were deve(oped and tested by lndirect immunofluorescence and Immunoperoxidase staining for reactivity with a panel of I 5 allogeneic tissues and 12 allogeneic cell llnes. The reactivity of such MAbs was restricted to melanoma cells from tumor biopsies and melanoma-derived cell lines. ln addition, all embryonie cells of all histiotypes from developmental stages later than mld·organogenesis and from corresponding short term in vitro cultures reacted with these MAbs. ln contrast, normal tissues and organs from adult fish dlsplayed no reactivity, thus implying that the melanoma-associated antigens detected by the MAbs described are oncofetal antigens.},
subject = {Physiologische Chemie},
language = {en}
}
@article{GesslerHameisterHenryetal.1990,
author = {Gessler, Manfred and Hameister, H. and Henry, I. and Junien, C. and Braun, T. and Arnold, H. H.},
title = {The human MyoD1 (MYF3) gene maps on the short arm of chromosome 11 but is not associated with the WAGR locus or the region for the Beckwith-Wiedemann syndrome},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59221},
year = {1990},
abstract = {The human gene encoding the myogenic determination factor myf3 (mouse MyoD1) has been mapped to the short arm of chromosome 11. Analysis of several somatic cell hybrids containing various derivatives with deletions or translocations revealed that the human MyoD (MYF3) gene is not associated with the WAGR locus at chromosomal band 11pl3 nor with the loss of the heterozygosity region at 11p15.5 related to the Beckwith-Wiedemann syndrome. Subregional mapping by in situ hybridization with an myf3 specific probe shows that the gene resides at the chromosomal band llp14, possibly at llp14.3.},
subject = {Biochemie},
language = {en}
}
@article{vanHeyningenBickmoreSeawrightetal.1990,
author = {van Heyningen, V. and Bickmore, W. A. and Seawright, A. and Fletcher, J. M. and Maule, J. and Fekete, G. and Gessler, Manfred and Bruns, G. A. and Huerre-Jeanpierre, C. and Junien, C.},
title = {Role for the Wilms tumor gene in genital development?},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59238},
year = {1990},
abstract = {No abstract available},
subject = {Biochemie},
language = {en}
}
@article{FialaMaschwitz1990,
author = {Fiala, Brigitte and Maschwitz, Ulrich},
title = {Studies on the south east asian ant-plant association Crematogaster borneensis / Macaranga: adaptations of the ant partner.},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32689},
year = {1990},
abstract = {C. borneensis (Myrmicinae) lives in dose association with several myrmecophytic species of the South East Asian pioneer tree genus Macaranga (Euphorbiaceae). The ants are adapted to the plants so dosely that they do not survive away from it. The only food they utilize is provided as food bodies by the plant and honeydew from specific scale insects kept inside the hollow internodes. The anatomy of the digestive tract is also adapted to life on the host plant: the crop is very sm all and can store only minute food quantities. C. borneensis exdusively colonizes certain Macaranga species. Queens as weIl as workers are able to recognize their host plant species, probably by chemical cues. Colony founding queens swarm throughout the year, mostly during darkness. There is strong competition among queens for host plants. Queens do not carry scale insects on their nuptial flight. Worker ants are active day and night. Most of them patrol and collect food bodies on the younger parts of the host plant. An important characteristic is their deaning behaviour, which results in removal of aIl foreign objects. Even though they are rather smalI, workers respond very aggressively to certain kinds of disturbance of the host plant. The ants attack most phytophagous insects and are especially effective in killing and removing smalI, softbodied herbivores (e.g. caterpillars). They do not possess a functional sting, but apply defensive secretion and-once biting an intruder-will not let go. Their effective alarm system results in a mass attack, which provides adequate defence for the colony and the host plant. A comparison with another Crematogaster species further illustrated the special adaptations of C. borneensis to its host plant.},
language = {en}
}
@article{WeisingFialaRamlochetal.1990,
author = {Weising, K. and Fiala, Brigitte and Ramloch, K. and Kahl, K. and Epplen, J. T.},
title = {Olingonucleotide fingerprinting in angiosperms},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42884},
year = {1990},
abstract = {No abstract available},
language = {en}
}
@article{DabauvalleLoosScheer1990,
author = {Dabauvalle, Marie-Christine and Loos, Karin and Scheer, Ulrich},
title = {Identification of a soluble precursor complex essential for nuclear pore assembly in vitro},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32801},
year = {1990},
abstract = {No abstract available},
language = {en}
}
@article{DandekarSibbald1990,
author = {Dandekar, Thomas and Sibbald, Peter R.},
title = {Trans-splicing of pre-mRNA is predicted to occur in a wide range of organisms including vertebrates},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29798},
year = {1990},
abstract = {No abstract available},
language = {en}
}
@article{Hovestadt1990,
author = {Hovestadt, Thomas},
title = {M{\"o}glichkeiten und Kriterien f{\"u}r die Bestimmung von Minimalarealen von Tierpopulationen und {\"O}kosystembest{\"a}nden},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30150},
year = {1990},
abstract = {No abstract available},
language = {de}
}
@article{GesslerPoustkaCaveneeetal.1990,
author = {Gessler, Manfred and Poustka, Annemarie and Cavenee, Webster and Neve, Rachael L. and Orkin, Stuart H. and Bruns, Gail A.},
title = {Homozygous deletion in Wilms tumours of a zinc-finger gene identified by chromosome jumping},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30122},
year = {1990},
abstract = {No abstract available},
language = {en}
}
@article{Hovestadt1990,
author = {Hovestadt, Thomas},
title = {Die Bedeutung zuf{\"a}lligen Aussterbens f{\"u}r die Naturschutzplanung},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30136},
year = {1990},
abstract = {No abstract available},
language = {de}
}
@article{Linsenmair1990,
author = {Linsenmair, Karl Eduard},
title = {Tropische Biodiversitat: Befunde und offene Probleme},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78302},
year = {1990},
abstract = {During the past 50 to over 100 million years communities evolved in the tropics which attained unprecedented levels of biodiversity, strikingly represented by evergreen lowland rain forests offering home to more than 50\% of all the world's extant species. Within only some 30 years human action reduced the area covered with tropical rain forests to about half of its former size, thereby negatively affecting local and global functions of the biosphere and exterminating an unknown number of species. With an exponentially increasing rate we are throwing away our and all future generations' biological heritage. We destroy the most complicated, scientifically most interesting living systems before we have gained any knowledge of their structures ,and dynamics. To understand the particular structures and dynamics of tropical communities means in the first place to understand the causes and consequences of their ten- to more than hundredfold higher alphadiversity (as compared to temperate systems). This problem has a historical dimension and a functional side requiring answers as to the nature of the proximate mechanisms of its maintenance. My review is only concerned with the latter aspect, and its maIn emphasis is on the gaps in our knowledge. Two sets of hypotheses have been developed for explaining the high within-commUnIty diversity. (1) According to the classical concept interspecific niche competition and subsequent niche separation are the main forces determining the structure of the community. These so-called equilibrium models have been contrasted in recent times with (2) non-equilibrium models. These models do not attribute the decisive role to interspecific competition. Strong niche overlaps are presumed to be very common within species-rich communities. Continuous stochastic local disturbances are assumed to prevent the achievement of any long-term equilibrium (climax) state. Being on the right spot at the right time is regarded as most important. Whether oneor a combination of both models provide the best key for understanding the structure of a special section within a community will certainly depend on many properties of the species at debate (mobility, disr.ersal, fertility etc.). For the vast majority of tropical organisms all such information is at present unavailable. The principles governing the structure of communities is just one of the very ,basic open problems. Another very prominent question is how the qualitatively very rich, however quantitatively poor resources are distributed among the members of highly diverse guilds of consumers and decomposers. Does the scarcity rather favour generalists or specialists, are small species overrepresented, are resources more extensively used than in temperate communities? One important property is fairly well established: Populations of most tropical species seem to be very small. Since a) in very many' cases distribution range is obviously very limited, since b) predator pressure is generally assumed to be higher in the tropics and c) recent - perhaps unduely generalized - results claim abundance fluctuations in the tropics fully comparable in their dimensions to those in the temperate zone, the question arises as to how these small populations can persist for seemingly long periods of time and avoid rapid extinction. Additionally treated PoInts concern detritivore communities, plant animal Interactions, key stone groups. Saving biodiversity in general and the tropical species and community richness in particular is one of the most urgent tasks of our generation, and biologists have to play a still more prominent role in this extremely important endeavor than they have in the past decades.},
subject = {Zoologie},
language = {de}
}
@article{BarnekowJahnSchartl1990,
author = {Barnekow, Angelika and Jahn, Reinhard and Schartl, Manfred},
title = {Synaptophysin: a substrate for the protein tyrosine kinase pp60c-src in intact synaptic vesicles},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86168},
year = {1990},
abstract = {Expression of pp60 c-src, the first well defined proto-oncogene product, is developmentally regulated and tissue-specific, with neuronal tissues displaying high amounts of the c-src encoded pp60 c-src kinase activity. In the central nervous system pp60 s-src is preferentially expressed in regions characterized by a high content of grey matter and elevated density of nerve terminals. In this study we show for the first time a direct interaction between pp60 c-src and synaptophysin as a physiological target protein in neurons by demonstrating that endogenous pp60 c-src is able to phosphorylate synaptophysin (p38). p38 is a major constituent of the synaptic vesicle membrane protein and is thought to play a key role in the exocytosis of small synaptic vesicles and possibly small clear vesicles in neuroendocrine cells.},
subject = {Synaptophysin},
language = {en}
}
@article{SchartlNandaSchluppetal.1990,
author = {Schartl, Manfred and Nanda, Indrajit and Schlupp, Ingo and Parzefall, Jakob and Schmid, Michael and Epplen, J{\"o}rg T.},
title = {Genetic variation in the clonal vertebrate Poecilia formosa is limited to few truly hypervariable loci},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86359},
year = {1990},
abstract = {No abstract available.},
subject = {Amazon Molly},
language = {en}
}
@article{FialaMebert1990,
author = {Fiala, Brigitte and Mebert, M.},
title = {Partnerschaft f{\"u}rs {\"U}berleben. Ameisenb{\"a}ume im tropischen Regenwald.},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42900},
year = {1990},
abstract = {No abstract available},
language = {de}
}
@article{SchartlSchartl1990,
author = {Schartl, Angelika and Schartl, Manfred},
title = {Genes and cancer: Molecular biology of the melanoma oncogene of Xiphophorus},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72670},
year = {1990},
abstract = {No abstract available.},
subject = {Schwertk{\"a}rpfling},
language = {en}
}
@article{LehrnbecherMerzSebaldetal.1991,
author = {Lehrnbecher, T. and Merz, H. and Sebald, Walter and Poot, M.},
title = {Interleukin 4 drives phytohemagglutinin-activated T cells through several cell cycles: no synergism between interleukin 2 and interleukin 4},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62491},
year = {1991},
abstract = {Cell kinetic studies of T cells stimulated with the interleukin 2 (11-2), D-4, or both lymphokines were performed with conventional [3H] thymidine incorporation and with the bivariate BrdU/Hoechst technique. 11-2 and 11-4 are able to drive phytohemagglutininactivated T cells through more than one cell cycle. Neither synergistic nor inhibitory efl'ect on T -cell proliferationwas seen for the stimulation with both 11-2 and 11-4 as compared with the effect ofll-2 alone. The quantitative data ofthe cell cycle distribution ofphytohemagglutininactivated T cells suggestthat the population ofll-4-responsive cells is at least an overlapping population, if not a real subset of the ·population of the 11-2-responsive cells.},
subject = {Biochemie},
language = {en}
}
@article{MerzFliednerOrschescheketal.1991,
author = {Merz, H. and Fliedner, A. and Orscheschek, K. and Binder, T. and Sebald, Walter and M{\"u}ller-Hermelink, H. K. and Feller, A. C.},
title = {Cytokine expression in T-cell lymphomas and Hodgkin's disease. Its possible implication in autocrine or paracrine production as a potential basis for neoplastic growth},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62483},
year = {1991},
abstract = {No abstract available},
subject = {Biochemie},
language = {en}
}
@article{KruseLehrnbecherSebald1991,
author = {Kruse, N. and Lehrnbecher, T. and Sebald, Walter},
title = {Site-directed mutagenesis reveals the importance of disulfide bridges and aromatic residues for structure and proliferative activity of human interleukin-4},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62505},
year = {1991},
abstract = {Mutant proteins (muteins) of human lnterleukin-4 (llA) were constructed by means of in vitro mutagenesis. The muteins were expressed in E. co/1, submitted to a renaturation and purification protocol and analysed for biological activity. Exchange of the cysteines at either position 46 or 99 which form one of the three disulfide bridges resulted. in a nearly co•mplete loss · of biological actiyity and an unstable protein. The exchange of tyrosine 124 also inactivated the protein, while a mutation of tyrosine 56 left some residual activity. Exchange of the other four cysteines or of · the single tryptophane had smaller etTects.},
subject = {Biochemie},
language = {en}
}
@article{PreiserSchmartzVanderLindenetal.1991,
author = {Preiser, J. C. and Schmartz, D. and Van der Linden, P. and Content, J. and Vanden Bussche, P. and Buurman, W. and Sebald, Werner and Dupont, E. and Pinsky, M. R. and Vincent, J. L.},
title = {Interleukin-6 administration has no acute hemodynamic or hematologic effect in the dog},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62511},
year = {1991},
abstract = {To investigate the possible hemodynamic efl'ects of interleukin-6 (IL-6), a single dose of 15 mcg/kg of recombinant IL-6 isolated from Escherichia coli was injected intravenously in six pentobarbital-anesthetized dogs. After 30 min, saline infusion was performed to maintain the - pulmonary artery balloon-occluded pressure at baseline Ievel. The animals were observed for up to 5 hours. No other hemodynamic alteration was observed than a gradual decline in cardiac output attributed to anesthesia. Hematologic variables, blood glucose, and total serum proteins were also constant. IL-6 levels were markedly elevated in the blood, bot no tumor necrosis factor activity was detected. Thus a primary role for IL-6 in the early cardiovascular alterations associated with septic shock seems unlikely.},
subject = {Biochemie},
language = {en}
}
@article{TonyLehrnbecherMerzetal.1991,
author = {Tony, H. P. and Lehrnbecher, T. and Merz, H. and Sebald, Werner and Wilhelm, M.},
title = {Regulation of IL-4 responsiveness in lymphoma B cells},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62520},
year = {1991},
abstract = {The responsiveness to IL-4 with and without costimulation with anti-IgM antibodies or phorbolester was studied in 35 cases of low grade non-Hodgkin Iymphoma by analyzing enhancement of CD23 and HLA dass li expression. The predominant phenotype responds directly to IL-4. Separate differentiation states can be distinguished according to coordinate or differential upregulation of CD23 and HLA dass II molecules by IL-4 alone, and differences in responsiveness to anti-IgM antibodies. A particular subgroup of B-lymphoma cells defines a separate stage of B-eeil differentiation. They fail to express high affinity binding sites for IL-4 and accordingly do not respond to IL-4- mediated signals. Cross-linking membrane lgM receptors or direct activation of protein kinase C via phorbolester induces IL-4 receptor expression and subsequent IL-4 reactivity.},
subject = {Biochemie},
language = {en}
}
@article{FoernzlerWittbrodtSchartl1991,
author = {F{\"o}rnzler, Dorothee and Wittbrodt, Joachim and Schartl, M.anfred},
title = {Analysis of an esterase linked to a locus involved in the regulation of the melanoma oncogene and isolation of polymorphic marker sequences in Xiphophorus},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61726},
year = {1991},
abstract = {Melanoma formation in Xiphophorus hybrids is mediated by a growth factor receptor tyrosine kinase oncogene encoded by the Tu locus. In the wild-type parental fish no tumors occur due to the activity of a locus that regulates the activity of the melanoma oncogene. Molecu/ar identification of this regulatory locus (R) requires a precise physical map of the chromosomal region. Therefore we studied esterase isozymes in Xiphophorus, two of which have been previously reported to be linked to locus R. We confinn that ES 1 is a distant marker for R ( approx. 30cM), and contrary to earlier studies, we show that this isozyme is present in all species of the genus and at similar activity Ievels in all organs tested. ES4, which has also been reported to be linked to R, was found to be a misclassification of liver ES1. In an attempt to identify markersthat bridge the large distance between ESl and R, we have generated DNA probes which are highly polymorphic. They will be useful in finding Iandmarks on a physical map of the R-containing chromosomal region.},
subject = {Physiologische Chemie},
language = {en}
}
@article{SchartlSchluppSchartletal.1991,
author = {Schartl, Manfred and Schlupp, Ingo and Schartl, Angelika and Meyer, Manfred K. and Nanda, Indrajit and Schmid, Michael and Epplen, J{\"o}rg T. and Parzefall, Jakob},
title = {On the stability of dispensable constituents of the eukaryotic genome: Stability of coding sequences versus truly hypervariable sequences in a clonal vertebrate, the amazon molly, Poecilia formosa},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61731},
year = {1991},
abstract = {In dooal unisexual vertebrales, the genes specifying the males become dispensable. To study tbe rate of such geoes the gynogeoetic all-female fisb Poecilillfonnolll was treated with androgens. Phenotypic males were obtained that exbibited the complete set of male cbaracteristics of dosely related gooocboristic species, induding body proportions, pigmentation, the extremely complex insemination apparatus of poecil{\"u}d fish, sexual bebavior, and spermatogeoesls. Tbe apparent stabllity of such genic structures, induding those involved in androgen regulation, is contrasted by high instability of noncoding sequeaces. Frequent mutations, thelr donal transmission, and at least two truly hypervariable Iod leading to individual difl'ereaces between these othenrise donal organisms were detected by DNA fingerprinting. These observations substantiate the concept that also in "ameiotic" vertebrates certain compartments of the genome are more prooe to mutatiooal alterations than others.},
subject = {Physiologische Chemie},
language = {en}
}
@article{WinklerVielkindSchartl1991,
author = {Winkler, Christoph and Vielkind, J{\"u}rgen R. and Schartl, Manfred},
title = {Transient expression of foreign DNA during embryonic and larval development of the medaka fish (Oryzias latipes)},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61743},
year = {1991},
abstract = {Species of small fish are becoming useful tools for studies on vertebrate development. Wehave investigated the developing embryo of the Japanese medaka for its application as a transient expression system for the in vivo analysis of gene regulation and function. The temporaland spatial expression patterns ofbacterial chloramphenicol acetyltransferase and galactosidase reporter genes injected in supercoiled plasmid form into the cytoplasm of one cell of the two-cell stage embryo was promoter-specific. The transient expression was found to be mosaic within the tissue and organs reflecting the unequal distribution of extrachromosomal foreign DNA and the intensive cell mixing movements that occur in fish embryogenesis. The expression data are consistent with data on DNA fate. Foreign DNA persisted during embryogenesis and was still detectable in some 3- and 9-month-old adult fish; it was found in high molecular weight form as weil as in circular plasmid conformations. The DNA was replicated during early and late embryogenesis. Our data indicate that the developing medaka embryo is a powerful in vivo assay system for studies of gene regulation and function.},
subject = {Physiologische Chemie},
language = {en}
}
@article{HaasBrehmKreftetal.1991,
author = {Haas, Albert and Brehm, Klaus and Kreft, J{\"u}rgen and Goebel, Werner},
title = {Cloning, characterization, and expression in Escherichia coli of a gene encoding Listeria seeligeri catalase, a bacterial enzyme highly homologous to mammalian catalases},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60536},
year = {1991},
abstract = {A gene coding for catalase (hydrogen-peroxide:hydrogen-peroxide oxidoreductase; EC 1.11.1.6) of the grain-positive bacterium Listeria seeligeri was cloned from a plasmid library of EcoRI-digested chromosomal DNA, with Escherichia coli DHSa as a host. The recombinant catalase was expressed in E. coli to an enzymatic activity approximately SO times that of the combined E. coli catalases. The nucleutide sequence was determined, and the deduced amino acid sequence revealed 43.2\% amino acid sequence identity between bovine liver catalase and L. seeligeri catalase. Most of the amino acid residues which are involved in catalytic activity, the formation of the active center accession channel, and heme binding in bovine liver catalase were also present in L. seeligeri catalase at the corresponding positions. The recombinant protein contained 488 amino acid residues and had a calculated molecular weight of 55,869. The predicted isoelectric point was 5.0. Enzymatic and genetic analyses showed that there is most probably a single catalase of this type in L. seeligeri. A perfect 21-bp inverted repeat, which was highly homologous to previously reported binding sequences of the Fur (ferric uptake regulon) protein of E. coli, was detected next to the putative promoter region of tbe L. seeligeri catalase gene.},
subject = {Biologie},
language = {en}
}
@article{SchueleinKreftGonskietal.1991,
author = {Sch{\"u}lein, Ralf and Kreft, J{\"u}rgen and Gonski, Sigrid and Goebel, Werner},
title = {Preprosubtilisin Carlsberg processing and secretion is blocked after deletion of amino acids 97-101 in the mature part of the enzyme},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60577},
year = {1991},
abstract = {During an investigation into the substrate specificity and processing of subtilisin Carlsberg from Bacillus licheniformis, two major independent findings were made: (i) as has been shown previously, a stretch of five amino acids (residues 97-101 of the mature enzyme) that loops out into the binding cleft is involved in substrate binding by subtilisin Carlsberg. In order to see whether this loop element also determines substrate specificity, the coding region for these five amino acids was deleted from the cloned gene for subtilisin Carlsberg by site-directed mutagenesis. Unexpectedly the resulting mutant preproenzyme (P42c, Mr=42 kDa) was not processed to the mature form (Mr = 30 kDa) and was not released into the medium by a proteasedeficient B. subtilis host strain; rather, it accumulated in the cell membrane. This result demonstrates that the integrity of this loop element, which is very distant from the processing cleavage sites in the preproenzyme, is required for secretion of subtilisin Carlsberg. (ii) In culture supernatants from B. subtilis harbouring the cloned wild-type subtilisin Carlsberg gene the transient appearance (at 0-3 h after onset of stationary phase) of a processing intermediate (P38c, Mr = 38 kDa) oftbis protease could be demonstrated. P38c very probably represents a genuine proform of subtilisin Carlsberg.},
subject = {Biologie},
language = {en}
}
@article{VortkampThiasGessleretal.1991,
author = {Vortkamp, A. and Thias, U. and Gessler, Manfred and Rosenkranz, W. and Kroisel, P. M. and Tommerup, N. and Kruger, G. and Gotz, J. and Pelz, L. and Grzeschik, Karl-Heinz},
title = {A somatic cell hybrid panel and DNA probes for physical mapping of human chromosome 7p},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59217},
year = {1991},
abstract = {No abstract available},
subject = {Biochemie},
language = {en}
}
@article{DabauvalleLoosMerkertetal.1991,
author = {Dabauvalle, Marie-Christine and Loos, Karin and Merkert, Hilde and Scheer, Ulrich},
title = {Spontaneous assembly of pore complex-containing membranes ("Annulate lamellae") in Xenopus egg extract in the absence of chromatin},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32797},
year = {1991},
abstract = {No abstract available},
language = {en}
}
@article{VortkampGesslerGrzeschik1991,
author = {Vortkamp, Andrea and Gessler, Manfred and Grzeschik, Karl-Heinz},
title = {GLI3 zinc-finger gene interrupted by translocations in Greig syndrome families},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30100},
year = {1991},
abstract = {No abstract available},
language = {de}
}
@article{DandekarTollervey1991,
author = {Dandekar, Thomas and Tollervey, D.},
title = {Thirty-three nucleotides of 5' flanking sequence including the TATA box are necessary and sufficient for efficient U2 snRNA transcription in Schizosaccharomycespombe},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29959},
year = {1991},
abstract = {No abstract available},
language = {en}
}
@article{DandekarStripeckeGrayetal.1991,
author = {Dandekar, Thomas and Stripecke, Renata and Gray, Nicola K. and Goossen, Britta and Constable, Anne and Johansson, Hans E. and Hentze, Matthias W.},
title = {Identification of a novel iron-responsive element in murine and human erythroid \(\delta\)-aminolevulinic acid synthase mRNA},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29929},
year = {1991},
abstract = {No abstract available},
language = {en}
}
@article{MaschwitzFialaMoogetal.1991,
author = {Maschwitz, Ulrich and Fiala, Brigitte and Moog, J. and Saw, L. G.},
title = {Two new myrmecophytic associations from the Malay Peninsula: ants of the genus Cladomyrma as partners of Saraca thaipingensis and Crypteronia griffithii},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32992},
year = {1991},
abstract = {In Peninsular Malaysia the trees Saraca thaipingensis (Caesalpiniaceae) and Crypteronia griffithii (Crypteroniaceae) are inhabited by ants. In the vicinity ofGombak, near Kuala Lumpur, the hollow internodes of young Saraca thaipingensis plants are colonized mainly by two Cladomyrma species. In larger trees a Crematogaster sp. is also found. Crypteronia griffithii is inhabited by a third species of Cladomyrma. None of these species is conspecific with any of the three Cladomyrma taxa so far described. The colonies are founded by single mated queens, which have a conspicuous, sphecid wasp-like behaviour when searching for host plants and nest sites. They chew holes into the plant intern odes and hollow them out to provide nest sites. Coccids and pseudococcids are cultivated within the internodes. The homopterans are not carried by queens on their nuptial flights. They apparently find their way by themselves into the cavities or are perhaps carried there by the worker ants. The Cladomyrma ants on Crypteronia are not aggressive, in contrast to those on Saraca thaipingensis. The relationship of Crypteronia with ants seems to be obligatory, whereas Saraca was only partly colonized by Cladomyrma. The interaction of Saraca with Crematogaster sp. is loose and facultative, since the Crematogaster sp. also lives on other tree species. Our studies have now revealed four Cladomyrma spp. which are regularly associated with plants. The genus therefore seems to have an entirely myrmecophytic way of life.},
language = {en}
}
@article{Linsenmair1991,
author = {Linsenmair, Karl Eduard},
title = {Allokation elterlicher Investition beim Bienenwolf Philantus triangulum (Hymenoptera: Sphecidae)},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78191},
year = {1991},
abstract = {No abstract available},
subject = {Zoologie},
language = {de}
}
@article{SchluppParzefallSchartl1991,
author = {Schlupp, I. and Parzefall, J. and Schartl, Manfred},
title = {Male mate choice in mixed bisexual/-unisexual breeding complexes of Poecilia (Teleostei: Poeciliidae)},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-80309},
year = {1991},
abstract = {The livebearing all-female fish Poecilia formosa reproduces by gynogenesis, a modified form of parthenogenesis. P. formosa forms at least two breeding complexes: in its northern range it exists sympatrically with Poecilia latipinna and in its southern range with Poecilia mexicana. Differences between these complexes and their possible origin are discussed. Embryogenesis is triggered by sperm of males of these closely related sympatric species. Because inheritance is stricdy maternal, from the male point of view energy and time invested are totally lost. In this study we wanted to elucidate whether males are able to distinguish between conspecific and parasitic females. It could be shown that males are able to distinguish females optically, but that this ability was obscured as soon as chemical and/or tactile contact was possible. Furthermore, we found that females in an attractive phase of their sexual cycle are always preferred, regardless of species. This is possibly the mechanism by which parasitic females obtain the matings they need to reproduce.},
subject = {Poecilia (Teleostei: Poeciliidae)},
language = {en}
}
@article{MalitschekSchartl1991,
author = {Malitschek, B. and Schartl, Manfred},
title = {Rapid identification of recombinant baculoviruses using PCR},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-80328},
year = {1991},
abstract = {no abstract available},
subject = {PCR},
language = {en}
}
@article{Fiala1991,
author = {Fiala, Brigitte},
title = {Partnerschaften von Pflanzen und Ameisen: Ameisenb{\"a}ume im malaysischen Regenwald.},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42936},
year = {1991},
abstract = {No abstract available},
language = {de}
}
@article{FialaMaschwitz1991,
author = {Fiala, Brigitte and Maschwitz, Ulrich},
title = {Extrafloral nectaries in the genus Macaranga (Euphorbiaceae) in Malaysia: comparative studies of their possible significance as predispositions for myrmecophytism.},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42863},
year = {1991},
abstract = {So me species of the paleotropical tree genus Macaranga (Euphorbiaceae) live in elose association with ants. Thc genus comprises the full range of species from those not regularly inhabited by ants to obligate myrmecophytes. In Malaysia (peninsular and Borneo) 23 ofthe 52 species areknown to be ant-associated (44\%). The simplest structural adaptation of plants to attract ants are extrafloral nectaries. We studied the distribution of extraflural nectaries in the genus Macaranga to assess the significance of this character as a possible predisposition for the evolution of obligate myrmecophytism. All species have marginal glands on the leaves. However, only the glands of nonmyrmecophytic species function as nectaries, whereas liquids secreted by these glands in myrmecophytic species did not contain sugar. Some non-myrmecophytic Macaranga and transitional Macaranga species in addition have extrafloral nectaries on the leaf blade near the petiole insertion. All obligatorily myrmecophytic Macaranga species, however, lack additional glands on the lamina. The non-myrmecophytic species are visited by a variety of different ant species, whereas myrmecophytic Macaranga are associated only with one specific ant-partner. Since these ants keep scale insects in the hollow sterns, reduction of nectary production in ant-inhabited Macaranga seems to be biologically significant. We interpret this as a means of (a) saving the assimilates and (b) stabilization of maintenance of the association's specificity. Competition with other ant species for food rewards is avoided and thereby danger ofweakening the protective function ofthe obligate antpartner for the plant is reduced. A comparison with other euphorb species living in the same habitats as Macaranga showed that in genera in which extrafloral nectaries are widespread, no myrmecophytes have evolved. Possession of extrafloral nectaries does not appear to be essential for the development of symbiotic ant-plant interactions. Other predispositions such as nesting space might have played a more important role.},
subject = {Macaranga},
language = {en}
}
@article{SchartlErbeldingDenkNandaetal.1991,
author = {Schartl, Manfred and Erbelding-Denk, Claudia and Nanda, Indrajit and Schmid, Michael and Schr{\"o}der, Johannes Horst and Epplen, J{\"o}rg T.},
title = {Mating success of subordinate males in a poeciliid fish species, Limia perugiae},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86349},
year = {1991},
abstract = {No abstract available.},
subject = {Lebendgeb{\"a}rende Zahnkarpfen},
language = {en}
}
@article{AdamMauelerSchartl1991,
author = {Adam, Dieter and Maueler, Winfried and Schartl, Manfred},
title = {Transcriptional activation of the melanoma inducing Xmrk oncogene in Xiphophorus},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87584},
year = {1991},
abstract = {The melanoma inducing locus of Xiphophorus encodes a tumorigenic version of a novel putative receptor tyrosine kinase (Xmrk). To elucidate the mechanism of oncogenic activation of Xmrk, we compared the structure and expression of two oncogenic loci with the corresponding proto-oncogene. Only minor structural alterations were found to be specific for the oncogenic Xmrk genes. Marked overexpression of the oncogene transcripts in melanoma, which are approximately 1 kb shorter than the proto-oncogene transcript, correlates with the malignancy of the tumors. The tumor transcripts are derived from an alternative transcription start site that is used only in the oncogenic loci. Thus, oncogenic activation of the melanoma inducing Xmrk gene appears primarily to be due to novel transcriptional control and overexpression.},
subject = {Schwertk{\"a}rpfling},
language = {en}
}
@article{HannigOttilieSchartl1991,
author = {Hannig, Gerhard and Ottilie, Sabine and Schartl, Manfred},
title = {Conservation of structure and expression of the c-yes and fyn genes in lower vertebrates},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86723},
year = {1991},
abstract = {The src-gene family in mammals and birds consists of 9 closely related protein tyrosine kinases. We have cloned the c-yes and fyn bomologues of the src-family from the teleost fish Xiphophorus helleri. Both genes show a high degree of sequence conservation and exhibit all structural motifs diagnostic for functional src-like protein tyrosine kinases. Sequence comparisons revealed three domains (exon 2, exons 3--6, exons 7-12) which evolve at different rates. Both genes exhibit an identical expression pattern, with preferential expression in neural tissues. No transcripts of c-yes were found in liver wbich is contrary to the situation in higher vertebrales. In malignant melanoma, elevated Ieveis of c-yes andfyn were detected indicating a possible function during secondary steps of tumor progression for src-related tyrosine kinases.},
subject = {Konservierung},
language = {en}
}
@article{ThiryScheerGoessens1991,
author = {Thiry, Marc and Scheer, Ulrich and Goessens, Guy},
title = {Localization of nucleolar chromatin by immunocytochemistry and in situ hybridization at the electron microscopic level},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-39289},
year = {1991},
abstract = {Nucleoli are the morphological expression of the activity of a defined set of chromosomal segments bearing rRNA genes. The topological distribution and composition of the intranucleolar chromatin as well as the definition of nucleolar structures in which enzymes of the rDNA transcription machinery reside have been investigated in mammalian cells by various immunogold labelling approaches at the ultrastructural level. The precise intranucleolar location of rRNA genes has been further specified by electron microscopic in situ hybridization with a non-autoradiographic procedure. Our results indicate that the fibrillar centers are the sole nucleolar structures where rDNA, core histones, RNA polymerase I and DNA to po isomerase I are located together. Taking into account the potential value and limitations of immunoelectron microscopic techniques, we propose that transcription of the rRNA genes takes place within the confines of the fibrillar centers, probably close to the boundary regions to the surrounding dense fibrillar component.},
language = {en}
}
@article{SchartlAdam1992,
author = {Schartl, Manfred and Adam, Dieter},
title = {Molecular cloning, structural characterization, and analysis of transcription of the melanoma oncogene of xiphophorus},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61989},
year = {1992},
abstract = {No abstract available},
subject = {Physiologische Chemie},
language = {en}
}
@article{SchluppParzefallEpplenetal.1992,
author = {Schlupp, Ingo and Parzefall, Jakob and Epplen, J{\"o}rg T. and Nanda, Indrajit and Schmid, Michael and Schartl, Manfred},
title = {Pseudomale behaviour and spontaneous masculinization in the all-female teleost Poecilia formosa (Teleostei: Poeciliidae)},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61688},
year = {1992},
abstract = {Pseudosexual behaviour is a rare phenomenon associated with unisexuality in vertebrates. In the gynogenetic, all-female teleost Poecilia formosa, rare individuals occur that resemble males of closely related gonochoristic species both in behaviour and external morphology. These masculinized gynogens and normal gynogens are members of the same clone, as demonstrated by DNA-fingerprinting. The behaviour of these masculinized gynogens is described and compared to the behaviour of the gonochoristic species Poecilia mexicana, P. latipinna and their hybrid as weil as androgen-treated individuals of P. formosa. No statistically significant difTerences were found between masculinized gynogens and hormonetreated individuals nor between the gonochoristic P. mexicana and P. latipinna males. Differences exist between gonochoristic and unisexual species. Passihle causes and effects of masculinized gynogens are discussed.},
subject = {Physiologische Chemie},
language = {en}
}
@article{KruseTonySebald1992,
author = {Kruse, N. and Tony, H. P. and Sebald, Walter},
title = {Conversion of human interleukin-4 into a high affinity antagonist by a single amino acid replacement},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62469},
year = {1992},
abstract = {lnterleukin-4 (IL-4) represents a prototypic lymphokine (for a recent review see Paul, 1991). It promotes differentiation of B-cells and the proliferation of T- and B-cell, and other cell types of the lymphoid system. An antagonist of human IL-4 was discovered during the studies presented here after Tyr124 of the recombinant proteinbad been substituted by an aspartic acid residue. This IL-4 variant, Y124D, bound with high affinity to the IL-4 receptor (K\(_D\) = 310 pM), but retained no detectable proliferative activity for T -<:ells and inhibited IL-4-dependent T -cell proliferation competitively (K\(_i\) = 620 pM). The loss of efficacy in variant Y124D was estimated to be > 100-fold on the basis of a weak partial agonist activity for the very sensitive induction of CD23 positive B-cells. The subsitution of Tyr124 by either phenylalanine, histidine, asparagine, Iysine or glycine resulted in partial agonist variants with unaltered receptor binding atTmity and relatively small deficiencies in efficacy. These results demoostrate that high affinity binding and signal generation can be uncoupled efticiently in a Iigand of a receptor betonging to the recently identified hematopoietin receptor family. In addition we show for the first time, that a powerful antagonist acting on the IL-4 receptor system can be derived from the IL-4 protein.},
subject = {Biochemie},
language = {en}
}
@article{DummerPosseckertNestleetal.1992,
author = {Dummer, R. and Posseckert, G. and Nestle, F. and Witzgall, R. and Burger, M. and Becker, J. C. and Sch{\"a}fer, E. and Wiede, J. and Sebald, Walter and Burg, G.},
title = {Soluble interleukin-2 receptors inhibit interleukin 2-dependent proliferation and cytotoxicity: explanation for diminished natural killer cell activity in cutaneous T-cell lymphomas in vivo?},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62473},
year = {1992},
abstract = {No abstract available},
subject = {Biochemie},
language = {en}
}
@article{HongSchartl1992,
author = {Hong, Yunhan and Schartl, Manfred},
title = {Structure of the rainbow trout metallothionein A gene},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61679},
year = {1992},
abstract = {To investigate the regulation of metallothionein-encoding genes in fish, we have isolated and sequenced the rainbow trout metallothionein-A-encoding gene (tMT-A) by polymerase chain reaction. This gene spans about 1.1 kb, consists of three exons and two introns, and has an A+ T-rieb 5' -region which contains a TATAAA signal, and two metal responsive elements (MREs). The transcription start point is centered around an A residue 81 nt upstream of the ATG codon.},
subject = {Physiologische Chemie},
language = {en}
}
@article{WittbrodtLammersMalitscheketal.1992,
author = {Wittbrodt, Joachim and Lammers, Reiner and Malitschek, Barbara and Ullrich, Axel and Schartl, Manfred},
title = {Xmrk receptor tyrosine kinase is activated in Xiphophorus malignant melanoma},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61699},
year = {1992},
abstract = {Xmrk encodes a putative transmembrane glycoprotein of the tyrosine kinase family and is a melanoma-inducing gene in Xiphophorus. We attempted to investigate the biological function of the putative Xmrk receptor by characterizing its signalling properties. Since a potential Iigand for Xmrk has not yet been identified, it has been difficult to analyse the biochemical properlies and biological function of this cell surface protein. In an approach towards such analyses, the Xmrk extracellular domain was replaced by the closely related Iigand-binding domain sequences of the human epidennal growth factor receptor (HER) and the ligand-induced activity of the chimeric HER-Xmrk proteinwas examined. We show that the Xmrk protein is a functional receptor tyrosine kinase, is highly active in malignant melanoma and displays a constitutive autophosphorylation activity possibly due to an activating mutation in its extracellular or transmembrane domain. In the focus formation assay the HER-Xmrk chimera is a potent transfonning protein equivalent to other tyrosine kinase oncoproteins.},
subject = {Physiologische Chemie},
language = {en}
}
@article{GoetzRaulfSchartl1992,
author = {G{\"o}tz, Rudolf and Raulf, Friedrich and Schartl, Manfrad},
title = {Brain-derived neurotrophic factor is more highly conserved in structure and function than nerve growth factor during vertebrate evolution},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61703},
year = {1992},
abstract = {Mammalian nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are members of a protein family with perfectly conserved domains arranged around the cysteine residues thought to stabilize an invariant three-dimensional scaffold in addition to distinct sequence motifs that convey different neuronal functions. To study their structural and functional conservation during evolution, we have compared NGF and BDNF from a lower vertebrate, the teleost fi.sh Xiphophorus, with the mammalian homlogues. Genomic clones encoding fish NGF and BDNF were isolated by cross-hybridization using probes from the cloned mammalian factors. Fish NGF and BDNF were expressed by means of recombinant vaccinia viruses, purified, and their neuronal survival specificities for different classes of neurons were found to mirror those of the mammalian factors. The half-maximal survival concentration for chick sensory neurons was 60 pg/ml for both fish and mammalian purifi.ed recombinant BDNF. However, the activity ofrecombinant fish NGF on both chick sensory and sympathetic neurons was 6 ng,lml, 75-fold lower than that of mouse NGF. The different functional conservation of NGF and BDNF is also reflected in their structures. The DNA-deduced amino acid sequences of processed mature fish NGF and BDNF showed, compared to mouse, 63\% and 90\% identity, respectively, indicating that NGF bad reached an optimized structure later than BDNF. The retrograde extrapolation of these data indicates that NGF and BDNF evolved at strikingly different rates ftom a common ancestral gene about 600 million years ago. By RNA gel blot anaJysis NGF mRNA was detected during late embryonie development; BDNF was present in adult brain.},
subject = {Physiologische Chemie},
language = {en}
}
@article{NandaSchartlFeichtingeretal.1992,
author = {Nanda, Indrajit and Schartl, Manfred and Feichtinger, Wolfgang and Epplen, J{\"o}rg T. and Schmid, Michael},
title = {Early stages of sex chromosome differentiation in fish as analysed by simple repetitive DNA sequences},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61715},
year = {1992},
abstract = {Animal sex chromosome evolution has started on different occasions with a homologous pair of autosomes leading to morphologically differentiated gonosomes. In contrast to other vertebrate classes, among fishes cytologically dernonstrahle sex chromosomes are rare. In reptiles, certain motifs of simple tandemly repeated DNA sequences like (gata)\(_n\)/(gaca)\(_m\) are associated with the constitutive heterochromatin of sex chromosomes. In this study a panel of simple repetitive sequence probes was hybridized to restriction enzyme digested genomic DNA of poeciliid fishes. Apparent male heterogamety previously established by genetic experiments in Poecilia reticulata (guppy) was correlated with male-specific hybridization using the (GACA)\(_4\) probe. The (GATA)\(_4\) oligonucleotide identifies certain male guppies by a Y chromosomal polymorphism in the outbred population. In cantrast none of the genetically defined heterogametic situations in Xiphophorus could be verified consistently using the collection of simple repetitive sequence probes. Only individuals from particular populations produced sex-specific patterns of hybridization with (GATA)\(_4\). Additional poeciliid species (P. sphenops, P. velifera) harbour different sex-specifically organized simple repeat motifs. The observed sex-specific hybridization patterns were substantiated by banding analyses of the karyotypes and by in situ hybridization using the (GACA)\(_4\) probe.},
subject = {Physiologische Chemie},
language = {en}
}
@article{BrehmHaasGoebeletal.1992,
author = {Brehm, Klaus and Haas, Albert and Goebel, Werner and Kreft, J{\"u}rgen},
title = {A gene encoding a superoxide dismutase of the facultative intracellular bacterium Listeria monocytogenes},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60515},
year = {1992},
abstract = {A gene (Imsod) encoding superoxide dismutase (SOD; EC 1.15.1.1) of the facultative intracellular pathogen, Listeria monocytogenes, was cloned by functional complementation of an SOD-deficient Escherichia coli mutant. The nucleotide sequence was determined and the deduced amino acid (aa) sequence (202 aa) showed close similarity to manganese-containing SOD's from other organisms. Subunits of the recombinant L. monocytogenes SOD (re-SOD) and of both E. coli SODs formed enzymatically active hybrid enzymes in vivo. DNA/DNA-hybridization experiments showed that this type of recombinant re-sod gene is conserved within the genus Listeria.},
subject = {Biologie},
language = {en}
}
@article{HaasDumbskyKreft1992,
author = {Haas, Albert and Dumbsky, Martina and Kreft, J{\"u}rgen},
title = {Listeriolysin genes: complete sequence of ilo from Listeria ivanovii and of lso from Listeria seeligeri},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60529},
year = {1992},
abstract = {The completc DNA scqucnccs coding for thc thiol-activated cytolysins from Listeria ivanovii, ivanolysin 0 (ILO) and for sccligerolysin 0 (LSO) from Listeria seeligeri have been dctermined. Thc deduced amino acid scquences revealed that: (i) the primary translation products comprise 528 (ILO) and 530 (LSO) amino acids. respectively. (ii) ILO contains two cysteines. LSO has a substitution in the conserved cysteine motif.},
subject = {Biologie},
language = {en}
}
@article{GesslerGrupeGrzeschiketal.1992,
author = {Gessler, Manfred and Grupe, Andrew and Grzeschik, Karl-Heinz and Pongs, Olaf},
title = {The potassium channel gene HK1 maps to human chromosome 11p14.1, close to the FSHB gene},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59184},
year = {1992},
abstract = {Transiently activating (A-type) potassium (K) channels are important regulators of action potential and action potential firing frequencies. HK1 designates the firsthuman cDNA that is highly homologous to the rat RCK4 cDNA that codes for an A-type K-channel. The HK1 channel is expressed in heart. By somatic cell hybrid analysis, the HK1 gene has been assigned to human chromosome 11p13-pl4, the WAGR deletion region (Wilms tumor, aniridia, genito-urinary abnormalities and mental retardation). Subsequent pulsed field gel (PFG) analysis and comparison with the well-established PFG map of this region localized the gene to 11p14, 200-600 kb telomeric to the FSHB gene.},
subject = {Biochemie},
language = {en}
}
@article{GesslerKoenigBruns1992,
author = {Gessler, Manfred and K{\"o}nig, A. and Bruns, G. A. P.},
title = {The genomic organization and expression of the WT1 gene},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59195},
year = {1992},
abstract = {The Wilms tumor gene WTl, a proposed tumor suppressor gene, has been identifled based on its location within a homozygous deletion found in tumor tissue. The gene encodes a putative transcription factor containing a Cys/His zinc finger domain. The critical homozygous deletions, however, are rarely seen, suggesting that in many cases the gene may be inactivated by more subtle alterations. To facilitate the seareh for smaller deletions and point mutations we have established the genomic organization of the WTl gene and have determined the sequence of all 10 exons and flanking intron DNA. The pattern of alternative splicing in two regions has been characterized in detail. These results will form the basis for future studies of mutant alleles at this locus.},
subject = {Biochemie},
language = {en}
}
@article{WolfKlugHackenbergetal.1992,
author = {Wolf, Markus and Klug, J{\"o}rg and Hackenberg, Reinhard and Gessler, Manfred and Grzeschik, Karl-Heinz and Beato, Miguel and Suske, Guntram},
title = {Human CC10, the homologue of rabbit uteroglobin: genomic cloning, chromosomal localization and expression in endometrial cell lines},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59206},
year = {1992},
abstract = {No abstract available},
subject = {Biochemie},
language = {en}
}
@article{FialaMaschwitz1992,
author = {Fiala, Brigitte and Maschwitz, Ulrich},
title = {Food bodies and their significance for obligate ant-association in the tree genus Macaranga (Euphorbiaceae)},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32921},
year = {1992},
abstract = {The production of extrafloral nectar and food bodies plays an important role in many tropical ant-plant mutualisms. In Malaysia, a close association exists between ants and some species of the pioneer tree genus Macaranga (Euphorbiaccac). Macaranga is a very diverse genus which exhibits all stages ofintcraction with ants, from facultative to obligatory associations. The ants nest inside the hollow inlcrnodes and reed mainly on food budies provided by the plants. Food body production had previously been reported only in myrrnecophytic Macaranga species, where it is usually coneentrated on protected parts or the plants such as recurved stipules. We found that non-myrmecophytic Macaranga species also produce food bodies on leaves and stems, where they are collected by a variety or ants. Levels of food body production differ between facultatively and obligatorily ant-associated species but also among the various non-myrmecophytes. This may he rdated to the degree of interaction with ants. Food body production starts at a younger age in the myrmccophytic species than in the transitional or non-myrmcccophytic Macaranga. Although food bodies of the non-inhabited Macaranga species are collected by a variety of ants, there is nu evidence of association with specific ant species. Our observations suggest that food bodies enhance the evolution of ant-plant interactions. Production of food bodies alone, however, does not appear to be the most important factor for the development of obligate myrmccopllytism in Macaranga.},
language = {en}
}
@article{WeisingFiala1992,
author = {Weising, Kurt and Fiala, Brigitte},
title = {Botanische Eindr{\"u}cke vom Bako-Nationalpark / Sarawak},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-42947},
year = {1992},
abstract = {No abstract available},
language = {de}
}
@article{GrafeSchmuckLinsenmair1992,
author = {Grafe, T. Ulmar and Schmuck, Richard and Linsenmair, Karl Eduard},
title = {Reproductive energetics of the African Reed Frogs, Hyperolius viridiflavus and Hyperolius marmoratus},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31187},
year = {1992},
abstract = {No abstract available},
language = {en}
}
@article{KobeltLinsenmair1992,
author = {Kobelt, F. and Linsenmair, Karl Eduard},
title = {Adaptations of the reed frog Hyperolius viridiflavus (Hyperoliidae) to its arid environment. VI. The iridophores in the skin as radiation reflectors},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30563},
year = {1992},
abstract = {No abstract available},
language = {en}
}
@article{VortkampFranzGessleretal.1992,
author = {Vortkamp, Andrea and Franz, Thomas and Gessler, Manfred and Grzeschik, Karl-Heinz},
title = {Deletion of GLI3 supports the homology of the human Greig cephalopolysyndactyly syndrome (GCPS) and the mouse mutant extra toes (Xt)},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30166},
year = {1992},
abstract = {No abstract available},
language = {en}
}
@article{DandekarTollervey1992,
author = {Dandekar, Thomas and Tollervey, David},
title = {Mutational analysis of Schizosaccharomyces pombe U4 snRNA by plasmid exchange},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29969},
year = {1992},
abstract = {No abstract available},
language = {en}
}