@article{GesslerKoenigArdenetal.1994, author = {Gessler, Manfred and K{\"o}nig, A. and Arden, K. and Grundy, P. and Orkin, S. H. and Sallan, S. and Peters, C. and Ruyle, S. and Mandell, J. and Li, F. and Cavenee, W. and Bruns, G. A.}, title = {Infrequent mutation of the WT1 gene in 77 Wilms' Tumors}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34308}, year = {1994}, abstract = {Homozygous deletions in Wilms' tumor DNA have been a key step in the identification and isolation of the WTI gene. Several additional loci are also postulated to contribute to Wilms' tumor formation. To assess the frequency of WTI alterations we have analyzed the WTI locus in a panel of 77 Wilms' tumors. Eight tumors showed evidence for large deletions of several hundred or thousand kilobasepairs of DNA, some of which were also cytogenetically detected. Additional intragenic mutations were detected using more sensitive SSCP analyses to scan all 10 WTI exons. Most of these result in premature stop codons or missense mutations that inactivate the remaining WTI allele. The overall frequency of WTI alterations detected with these methods is less than 15\%. While some mutations may not be detectable with the methods employed, our results suggest that direct alterations of the WTI gene are present in only a small fraction of Wilms' tumors. Thus, mutations at other Wilms' tumor loci or disturbance of interactions between these genes likely play an important role in Wilms' tumor development.}, language = {en} } @article{SchmuckGeiseLinsenmair1994, author = {Schmuck, R. and Geise, W. and Linsenmair, Karl Eduard}, title = {Life cycle strategies and physiological adjustments of Reedfrog Tadpoles (Amphibia, Anura, Hyperoliidae) in relation to environmental conditions.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31009}, year = {1994}, abstract = {The relationship between different degrees of intraspecific crowding of reedfrog tadpoles and their physiological responses to a deterioration of the natal pond water quality was examined under laboratory conditions. Tadpoles that were reared at a lower density metamorphosed significantly earlier than those raised at a higher density. As density increases, the average body length at metamorphosis decreases. However, at low tadpole density, a significantly higher diversity of body size classes among freshly metamorphosed froglets was observed than under more crowded conditions. Mortality increased during metamorphic climax and was inversely correlated with the tadpole density. In ephemeral ponds, an accumulation of nitrogenous wastes from metabolic processes and/or a concentration by evaporation in prolonged rainless periods can pose a considerable chemical stress to reedfrog tadpoles. Hyperolius viridiflavus ommatostictus responded to an increasing ammonia concentration with an activity increase of the ornithine cycle (intensified urea synthesis). hi contrast, Hyperolius marmoratus taeniatus exhibited a strong tolerance against high ammonia levels. A deterioration of the natal pond water quality caused H. v. ommatostictus and H. v. nitidulus tadpoles to adjust to harsher climatic conditions at the time of metamorphosis. This physiological preadjustment enabled the froglets to start feeding and growing immediately after metamorphosis even at low air humidity and rare precipitation events. In contrast, froglets that were raised in daily refreshed water exhibited high mortality rates if subjected to identical conditions. As one possible indicator of the actual climatic conditions prevailing in the surrounding terrestrial habitat, fluctuations in the water ammonia level are discussed.}, language = {en} } @article{FialaGrunskyMaschwitzetal.1994, author = {Fiala, Brigitte and Grunsky, Harald and Maschwitz, Ulrich and Linsenmair, Karl Eduard}, title = {Diversity of ant-plant interactions: Protective efficacy in Macaranga species with different degrees of ant-association.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32905}, year = {1994}, abstract = {The pioneer tree Macaranga in SE Asia has developed manyfold associations with ants. The genus comprises all stages of interaction with ants, from facultative relationships to obligate myrmecophytes. Only myrmecophytic Macaranga offer nesting space for ants and are associated with a specific ant partner. The nonmyrmecophytic species are visited by a variety of different ant species which are attracted by extrafloral nectaries (EFN) and food bodies. Transitional Macaranga species like M. hosei are colonized later in their development due to their stem structure. Before the colonization by their specific Crematogaster partner the young plants are visited by different ant species attracted by EFN. These nectaries are reduced and food body production starts as soon as colonization becomes possible. We demonstrated earlier that obligate ant partners can protect their Macaranga plants against herbivore damage and vine cover. In this study we focused on nonspecific interactions and studied M. tanarius and M. hosei, representing a non-myrmecophyte and a transitional species respectively. In ant exclusion experiments both M. tanarius and M. hosei suffered significantly higher mean leaf damage than controls, 37\% versus 6\% in M. hosei, 16\% versus 7\% in M. tanarius. M. tanarius offers both EFN and food bodies so that tests for different effects of these two food rewards could be conducted. Plants with food bodies removed but with EFN remaining had the lowest mean increase of herbivore damage of all experimental groups. Main herbivores on M. hosei were mites and caterpillars. Many M. tanarius plants were infested by a shootborer. Both Macaranga species were visited by various ant species. Crematogaster spp. being the most abundant. We found no evidence for any specific relationships. The results of this study strongly support the hypothesis that non-specific, facultative associations with ants can be advantageous for Macaranga plants. Food bodies appear to have lower attractive value for opportunistic ants than EFN and may require a specific dietary adaptation. This is also indicated by the fact that food body production in the transitional M. hosei does not start before stem structure allows a colonization by the obligate Crematogaster species. M. hosei thus benefits from facultative association with a variety of ants until it produces its first domatia and can be colonized by its obligate mutualist.}, language = {en} } @article{VortkampGesslerPaslieretal.1994, author = {Vortkamp, Andrea and Gessler, Manfred and Paslier, D. Le and Elaswarapu, R. and Smith, S. and Grzeschik, Karl-Heinz}, title = {Isolation of a yeast artificial chromosome contig spanning the Greig cephalopolysyndactyly syndrome (GCPS) gene region}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30182}, year = {1994}, abstract = {Disruption of the zinc finger gene GLI3 has been shown to be the cause of Greig cephalopolysyndactyly syndrome (GCPS), at least in some GCPS translocation patients. To characterize this genomic region on human chromosome 7p13, we have isolated a VAC contig of more than 1000 kb including the GLI3 gene. In this contig the gene itself spans at least 200-250 kb. A CpG island is located in the vicinity of the 5' region of the known GLI3 cDNA, implying a potential promoter region.}, language = {en} } @article{ArgosDandekar1994, author = {Argos, P. and Dandekar, Thomas}, title = {Delineating the main chain topology of four-helix bundle proteins using the genetic algorithm and knowledge based on the amino acid sequence alone}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33807}, year = {1994}, abstract = {No abstract available}, subject = {Proteine}, language = {en} } @article{Linsenmair1994, author = {Linsenmair, Karl Eduard}, title = {Biologische Vielfalt und {\"o}kologische Stabilit{\"a}t}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31157}, year = {1994}, abstract = {No abstract available}, language = {en} } @article{ScheerWeisenberger1994, author = {Scheer, Ulrich and Weisenberger, Dieter}, title = {The nucleolus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32037}, year = {1994}, abstract = {No abstract available}, language = {en} } @article{DandekarArgos1994, author = {Dandekar, Thomas and Argos, P.}, title = {Folding the main chain of small proteins with the genetic algorithm}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29847}, year = {1994}, abstract = {No abstract available}, language = {de} } @misc{DandekarArgos1994, author = {Dandekar, Thomas and Argos, P.}, title = {Three-dimensional structure of the 67k N-terminal Fragment of E.coli DNA Topoisomerase I}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29836}, year = {1994}, abstract = {No abstract available}, language = {en} } @misc{DandekarDandekar1994, author = {Dandekar, Thomas and Dandekar, G.}, title = {Schlange als Attribut des {\"A}skulap}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29822}, year = {1994}, abstract = {No abstract available}, language = {de} }