@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}
}
@incollection{AdamSchartlAndexingeretal.1991,
author = {Adam, D. and Schartl, A. and Andexinger, S. and H{\"o}lter, S. and Wilde, B. and Schartl, Manfred},
title = {Genetic factors in tumour formation: The melanoma-inducing gene of Xiphophorus},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86388},
publisher = {Universit{\"a}t W{\"u}rzburg},
year = {1991},
abstract = {No abstract available.},
subject = {Humangenetik},
language = {en}
}
@incollection{EpplenAmmerEpplenetal.1991,
author = {Epplen, J. T. and Ammer, H. and Epplen, C. and Kammerbauer, C. and Mitreiter, R. and Roewer, L. and Schwaiger, W. and Steimle, V. and Zischler, H. and Albert, E. and Andreas, A. and Beyermann, B. and Meyer, W. and Buitkamp, J. and Nanda, I. and N{\"u}rnberg, P. and Pena, S. D. J. and P{\"o}che, H. and Sprecher, W. and Schartl, Manfred and Weising, K. and Yassouridis, A.},
title = {Oligonucleotide fingerprinting using simple repeat motifs: a convenient, ubiquitously applicable method to detect hypervariability for multiple purposes},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86371},
publisher = {Universit{\"a}t W{\"u}rzburg},
year = {1991},
abstract = {A panel of simple repetitive oligonucleotide probes has been designed and tested for multilocus DNA fingerprinting in some 200 fungal, plant and animal species as well as man. To date at least one of the probes has been found to be informative in each species. The human genome, however, has been the major target of many fingerprintins studies. Using the probe (CAC)5 or (GTG)5, individualization of all humans is possible except for monozygotic twins. Paternity analyses are now perfonned on a routine basis by the use of multilocus fingerprints, inctuding also cases of deficiency, i.e. where one of the parents is not available for analysis. In forensie science stain analysis is feasible in all tissue remains containing nuc)eated cells. Depending on the degree of DNA degradation a variety of oligonucleotides are informative, and they have been proven useful in actual case work. Advantages in comparison to other methods including enzymatic DNA amplification techniques (PCR) are evident. Fingerprint patterns of tumors may be changed due to the gain or loss of chromosomes and/or intrachromosomal deletion and amplification events. Locus-specific probes were isolated from the human (CAC)5/( GTG)5 fingerprint with a varying degree of informativeness (monomorphic versus truly hypervariable markers). The feasibility of three different approaches. for the isolation of hypervariable mono-locus probes was evaluated. Finally, one particular mixed simple (gt)n(ga)m repeat locus in the second intron of the HLA-DRB genes has been scrutinized to allow comparison of the extent of exon-encoded (protein-) polymorphisms versus intronie bypervariability of simple repeats: adjacent to a single gene sequence (e.g. HLA-DRB1*0401) many different length alleles were found. Group-specific structures of basic repeats were identified within the evolutionarily related DRB alleles. As a further application it is suggested here that due to the ubiquitous interspersion of their targets, short probes for simple repeat sequences are especially useful tools for ordering genomic cosmid, yeast artificial chromosome and phage banks.},
subject = {DNS},
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{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{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{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{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{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{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{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{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{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{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{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{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{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{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}
}
@inproceedings{FialaMaschwitzTho1991,
author = {Fiala, Brigitte and Maschwitz, Ulrich and Tho, Yow Pong},
title = {The association between Macaranga trees and ants in South-east Asia},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-54752},
year = {1991},
abstract = {No abstract available},
subject = {Macaranga},
language = {de}
}
@misc{DabauvalleScheer1991,
author = {Dabauvalle, Marie-Christine and Scheer, Ulrich},
title = {Assembly of nuclear pore complexes in Xenopus egg extract},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-41194},
year = {1991},
abstract = {No abstract available},
language = {en}
}
@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{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}
}
@misc{FischerWeissenbergerScheer1991,
author = {Fischer, Dagmar and Weißenberger, Dieter and Scheer, Ulrich},
title = {Assigning functions to nucleolar structures},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34258},
year = {1991},
abstract = {Nucleoli provide the fascinating possibility of linking morphologically distinct structures such as those seen in the electron microscope with biochemical f eatures of the formation and step wise maturation of ribosomes. Localization of proteins by immunocytochemistry and of rRNA genes and their transcripts by in situ hybridization has greatly improved our understanding of the structural-functional relationships of the nucleolus. The present review describes some recent results obtained by electron microscopic in situ hybridization and argues that this approach has the potential to correlate each step of the complex pre-rRNA maturation pathway with nucleolar structures. Evidence is accumulating that the nucleolus-specific U3 snRNPs (small nuclear ribonucleoprotein particles) participate in rRNA processing events, similar to the role played by the nucleoplasmic snRNPs in mRNA maturation. The intranucleolar distribution of U3 snRNA is consistent with the view that it is involved in both early and late stages of pre-rRNA processing.},
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{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}
}
@misc{Dandekar1991,
author = {Dandekar, Thomas},
title = {Olbers' Paradox (peer-reviewed scientific correspondence)},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31672},
year = {1991},
abstract = {No abstract available},
language = {en}
}
@book{HovestadtRoeserMuehlenberg1991,
author = {Hovestadt, Thomas and Roeser, J. and M{\"u}hlenberg, M.},
title = {Fl{\"a}chenbedarf von Tierpopulationen - als Kriterien f{\"u}r Maßnahmen des Biotopschutzes und als Datenbasis zur Beurteilung von Eingriffen in Natur und Landschaft},
isbn = {3-89336-057-3},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33645},
publisher = {Universit{\"a}t W{\"u}rzburg},
year = {1991},
abstract = {Die Untersuchung des Fl{\"a}chenanspruchs von Tierpopulationen ist wegen folgender Gesichtspunkte wichtig: (a) Nachdem das Aussterben der Arten nicht nachl{\"a}ßt, erhebt sich die Frage nach den M{\"o}glichkeiten im Naturschutz, quantitative Forderungen zu begr{\"u}nden. (b) Da selbst gezielte Schutzmaßnahmen sinnlos werden, wenn die Voraussetzungen f{\"u}r das {\"u}berleben der Arten oder Lebensgemeinschaften nicht gegeben sind, muß man sich fragen, wieviel an Umweltverschmutzung reduziert werden muß, damit der Artenschutz verwirklicht werden kann. Der "Extensivierungsspielraum" an sich reicht nicht aus. Die Frage nach dem Fl{\"a}chenanspruch schließt den Gedanken einer "mindestens notwendigen" Fl{\"a}chensicherung ein. Der Fl{\"a}chenbedarf einer Tierpopulation wird bestimmt durch (A) den Raumbedarf der Reproduktionseinheit, und (B) der Gr{\"o}ße einer {\"u}berlebensf{\"a}higen Population. (A) variiert durch die individuell und im Jahresverlauf schwankenden Aktionsraumgr{\"o}ßen und die unterschiedliche Habitatqualit{\"a}t. Die {\"u}berlebensf{\"a}higkeit (B) einer Population ist von Zufallsprozessen abh{\"a}ngig und daher nur mit einer gewissen Wahrscheinlichkeit absch{\"a}tzbar. Vier verschiedene (nicht anthropogene) Faktoren k{\"o}nnen selbst in einem geeigneten Habi tat zum Aussterben von Populationen f{\"u}hren: (a) demographische und (b) genetische Zufallsprozesse, (c) Umweltschwankungen und (d) (Natur) katastrophen. Eine Absicherung gegen diese Risikofaktoren wird durch Vergr{\"o}ßerung der Population, Erh{\"o}hung der Zahl geeigneter Habitate und Verringerung der Isolierung zwischen den bewohnten Fl{\"a}chen erreicht. Eine Mindestforderung (Minimalareal die mindest notwendige Fl{\"a}che, die gesch{\"u}tzt werden muß) kann nur an der sog. "minimum viable population" bemessen werden. Die Gef{\"a}hrdungsgradanalyse ("population vulnerability analysis") f{\"u}r eine bestimmte Tierart liefert die notwendigen Angaben zur Habitatqualit{\"a}t, Fl{\"a}chengr{\"o}ße und Lage der Fl{\"a}chen, die f{\"u}r die Zukunftssicherung einer Population unter nat{\"u}rlichen Bedingungen (z.B. "mit 95\%iger Wahrscheinlichkeit die n{\"a}chsten 50 Jahre {\"u}berlebensf{\"a}hig" ) notwendig sind. Sowohl beim konstruktiven Artenschutz wie auch f{\"u}r die Schadensbegrenzung bei Eingriffsregelungen sollte eine Zielart ausgew{\"a}hlt werden, damit die Fl{\"a}chensicherung eindeutig quantitativ begr{\"u}ndet werden kann. Die Auswahl einer Zielart erfolgt nach Kriterien wie {\"u}berregionaler Gef{\"a}hrdungsgrad, Schl{\"u}sselart, Chancen der Populationssicherung und wird regional nach den bestehenden Voraussetzungen (Vorkommen, Habitatangebot, Regionalplan) angepaßt. Die wesentlichen Aspekte eines ZielartenKonzeptes sind: Der Fl{\"a}chenbedarf f{\"u}r Schutz- und Ausgleichsmaßnahmen wird an den {\"U}berlebensaussichten einzelner Tierpopulationen bemessen -- Die Zukunftssicherung muß nat{\"u}rliche Bedingungen (nicht st{\"a}ndige St{\"u}tzmaßnahmen) voraussetzen -- Die Analyse von Risikofaktoren bildet die Grundlage f{\"u}r die Absch{\"a}tzung der Zukunftsaussichten. Es sind wissenschaftlich begr{\"u}ndete, quantitative Aussagen m{\"o}glich. Durch die Sicherung von Fl{\"a}chen mit geeigneter Habitatqualit{\"a}t profitieren viele weitere Arten von den Schutzmaßnahmen. Es entsteht ein k{\"u}nftiger Forschungsbedarf vor allem zu den Gef{\"a}hrdungsgradanalysen ausgew{\"a}hlter Zielarten. F{\"u}r die praktische Umsetzung sind die Aufstellung einer regional angepaßten Zielartenliste, Habitateignungsanalysen und die Entwicklung von Populationsmodellen f{\"u}r Zielarten von seiten der biologischen Wissenschaft n{\"o}tig.},
subject = {Tiere},
language = {de}
}
@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{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{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}
}
@misc{DandekarArgos1991,
author = {Dandekar, Thomas and Argos, Patrick},
title = {Chaperonin-mediated protein folding at the surface of groEL through a "molten globule" intermediate},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29939},
year = {1991},
abstract = {No abstract available},
language = {en}
}
@misc{Dandekar1991,
author = {Dandekar, Thomas},
title = {Yeast U3 localization and correct sequence (snR17a) and promotor activity (snR17b) identified by homology search},
url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29781},
year = {1991},
abstract = {No abstract available},
language = {en}
}