@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{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{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{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{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{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{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{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{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{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} }