TY - JOUR A1 - Zhang, Shaowu A1 - Si, Aung A1 - Pahl, Mario T1 - Visually guided decision making in foraging honeybees JF - Frontiers in Neuroscience N2 - Honeybees can easily be trained to perform different types of discrimination tasks under controlled laboratory conditions. This review describes a range of experiments carried out with free-flying forager honeybees under such conditions. The research done over the past 30 or so years suggests that cognitive abilities (learning and perception) in insects are more intricate and flexible than was originally imagined. It has become apparent that honeybees are capable of a variety of visually guided tasks, involving decision making under challenging situations: this includes simultaneously making use of different sensory modalities, such as vision and olfaction, and learning to use abstract concepts such as “sameness” and “difference.” Many studies have shown that decision making in foraging honeybees is highly flexible. The trained animals learn how to solve a task, and do so with a high accuracy, but when they are presented with a new variation of the task, they apply the learnt rules from the earlier setup to the new situation, and solve the new task as well. Honeybees therefore not only feature a rich behavioral repertoire to choose from, but also make decisions most apt to the current situation. The experiments in this review give an insight into the environmental cues and cognitive resources that are probably highly significant for a forager bee that must continually make decisions regarding patches of resources to be exploited. Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-124228 VL - 6 IS - 88 ER - TY - JOUR A1 - Heddergott, Nico A1 - Krüger, Timothy A1 - Babu, Sujin B. A1 - Wei, Ai A1 - Stellamanns, Erik A1 - Uppaluri, Sravanti A1 - Pfohl, Thomas A1 - Stark, Holger A1 - Engstler, Markus T1 - Trypanosome Motion Represents an Adaptation to the Crowded Environment ofthe Vertebrate Bloodstream N2 - Blood is a remarkable habitat: it is highly viscous, contains a dense packaging of cells and perpetually flows at velocities varying over three orders of magnitude. Only few pathogens endure the harsh physical conditions within the vertebrate bloodstream and prosper despite being constantly attacked by host antibodies. African trypanosomes are strictly extracellular blood parasites, which evade the immune response through a system of antigenic variation and incessant motility. How the flagellates actually swim in blood remains to be elucidated. Here, we show that the mode and dynamics of trypanosome locomotion are a trait of life within a crowded environment. Using high-speed fluorescence microscopy and ordered micro-pillar arrays we show that the parasites mode of motility is adapted to the density of cells in blood. Trypanosomes are pulled forward by the planar beat of the single flagellum. Hydrodynamic flow across the asymmetrically shaped cell body translates into its rotational movement. Importantly, the presence of particles with the shape, size and spacing of blood cells is required and sufficient for trypanosomes to reach maximum forward velocity. If the density of obstacles, however, is further increased to resemble collagen networks or tissue spaces, the parasites reverse their flagellar beat and consequently swim backwards, in this way avoiding getting trapped. In the absence of obstacles, this flagellar beat reversal occurs randomly resulting in irregular waveforms and apparent cell tumbling. Thus, the swimming behavior of trypanosomes is a surprising example of micro-adaptation to life at low Reynolds numbers. For a precise physical interpretation, we compare our high-resolution microscopic data to results from a simulation technique that combines the method of multi-particle collision dynamics with a triangulated surface model. The simulation produces a rotating cell body and a helical swimming path, providing a functioning simulation method for a microorganism with a complex swimming strategy KW - Biologie Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78421 ER - TY - JOUR A1 - Heddergott, Niko A1 - Krüger, Timothy A1 - Babu, Sujin B. A1 - Wei, Ai A1 - Stellamanns, Erik A1 - Uppaluri, Sravanti A1 - Pfohl, Thomas A1 - Stark, Holger A1 - Engstler, Markus T1 - Trypanosome Motion Represents an Adaptation to the Crowded Environment of the Vertebrate Bloodstream JF - PLoS Pathogens N2 - Blood is a remarkable habitat: it is highly viscous, contains a dense packaging of cells and perpetually flows at velocities varying over three orders of magnitude. Only few pathogens endure the harsh physical conditions within the vertebrate bloodstream and prosper despite being constantly attacked by host antibodies. African trypanosomes are strictly extracellular blood parasites, which evade the immune response through a system of antigenic variation and incessant motility. How the flagellates actually swim in blood remains to be elucidated. Here, we show that the mode and dynamics of trypanosome locomotion are a trait of life within a crowded environment. Using high-speed fluorescence microscopy and ordered micro-pillar arrays we show that the parasites mode of motility is adapted to the density of cells in blood. Trypanosomes are pulled forward by the planar beat of the single flagellum. Hydrodynamic flow across the asymmetrically shaped cell body translates into its rotational movement. Importantly, the presence of particles with the shape, size and spacing of blood cells is required and sufficient for trypanosomes to reach maximum forward velocity. If the density of obstacles, however, is further increased to resemble collagen networks or tissue spaces, the parasites reverse their flagellar beat and consequently swim backwards, in this way avoiding getting trapped. In the absence of obstacles, this flagellar beat reversal occurs randomly resulting in irregular waveforms and apparent cell tumbling. Thus, the swimming behavior of trypanosomes is a surprising example of micro-adaptation to life at low Reynolds numbers. For a precise physical interpretation, we compare our high-resolution microscopic data to results from a simulation technique that combines the method of multi-particle collision dynamics with a triangulated surface model. The simulation produces a rotating cell body and a helical swimming path, providing a functioning simulation method for a microorganism with a complex swimming strategy. KW - simulation KW - multiparticle collision dynamics KW - propulsion KW - viscosity KW - flagellar KW - motility KW - solvent KW - model KW - hydrodynamics KW - spiroplasma Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134595 VL - 8 IS - 11 ER - TY - JOUR A1 - Schmitt, Jana A1 - Backes, Christina A1 - Nourkami-Tutdibi, Nasenien A1 - Leidinger, Petra A1 - Deutscher, Stephanie A1 - Beier, Markus A1 - Gessler, Manfred A1 - Graf, Norbert A1 - Lenhof, Hans-Peter A1 - Keller, Andreas A1 - Meese, Eckart T1 - Treatment-independent miRNA signature in blood of wilms tumor patients JF - BMC Genomics N2 - Background Blood-born miRNA signatures have recently been reported for various tumor diseases. Here, we compared the miRNA signature in Wilms tumor patients prior and after preoperative chemotherapy according to SIOP protocol 2001. Results We did not find a significant difference between miRNA signature of both groups. However both, Wilms tumor patients prior and after chemotherapy showed a miRNA signature different from healthy controls. The signature of Wilms tumor patients prior to chemotherapy showed an accuracy of 97.5% and of patients after chemotherapy an accuracy of 97.0%, each as compared to healthy controls. Conclusion Our results provide evidence for a blood-born Wilms tumor miRNA signature largely independent of four weeks preoperative chemotherapy treatment. KW - miRNA Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-124034 VL - 13 IS - 379 ER - TY - JOUR A1 - Förster, Frank A1 - Beisser, Daniela A1 - Grohme, Markus A. A1 - Liang, Chunguang A1 - Mali, Brahim A1 - Siegl, Alexander Matthias A1 - Engelmann, Julia C. A1 - Shkumatov, Alexander V. A1 - Schokraie, Elham A1 - Müller, Tobias A1 - Schnölzer, Martina A1 - Schill, Ralph O. A1 - Frohme, Marcus A1 - Dandekar, Thomas T1 - Transcriptome analysis in tardigrade species reveals specific molecular pathways for stress adaptations JF - Bioinformatics and biology insights N2 - Tardigrades have unique stress-adaptations that allow them to survive extremes of cold, heat, radiation and vacuum. To study this, encoded protein clusters and pathways from an ongoing transcriptome study on the tardigrade \(Milnesium\) \(tardigradum\) were analyzed using bioinformatics tools and compared to expressed sequence tags (ESTs) from \(Hypsibius\) \(dujardini\), revealing major pathways involved in resistance against extreme environmental conditions. ESTs are available on the Tardigrade Workbench along with software and databank updates. Our analysis reveals that RNA stability motifs for \(M.\) \(tardigradum\) are different from typical motifs known from higher animals. \(M.\) \(tardigradum\) and \(H.\) \(dujardini\) protein clusters and conserved domains imply metabolic storage pathways for glycogen, glycolipids and specific secondary metabolism as well as stress response pathways (including heat shock proteins, bmh2, and specific repair pathways). Redox-, DNA-, stress- and protein protection pathways complement specific repair capabilities to achieve the strong robustness of \(M.\) \(tardigradum\). These pathways are partly conserved in other animals and their manipulation could boost stress adaptation even in human cells. However, the unique combination of resistance and repair pathways make tardigrades and \(M.\) \(tardigradum\) in particular so highly stress resistant. KW - RNA KW - expressed sequence tag KW - cluster KW - protein familiy KW - adaption KW - tardigrada KW - transcriptome Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123089 N1 - This is an open access article. Unrestricted non-commercial use is permitted provided the original work is properly cited. VL - 6 ER - TY - JOUR A1 - Nanguneri, Siddharth A1 - Flottmann, Benjamin A1 - Horstmann, Heinz A1 - Heilemann, Mike A1 - Kuner, Thomas T1 - Three-Dimensional, Tomographic Super-Resolution Fluorescence Imaging of Serially Sectioned Thick Samples JF - PLoS One N2 - Three-dimensional fluorescence imaging of thick tissue samples with near-molecular resolution remains a fundamental challenge in the life sciences. To tackle this, we developed tomoSTORM, an approach combining single-molecule localization-based super-resolution microscopy with array tomography of structurally intact brain tissue. Consecutive sections organized in a ribbon were serially imaged with a lateral resolution of 28 nm and an axial resolution of 40 nm in tissue volumes of up to 50 \(\mu\)mx50\(\mu\)mx2.5\(\mu\)m. Using targeted expression of membrane bound (m)GFP and immunohistochemistry at the calyx of Held, a model synapse for central glutamatergic neurotransmission, we delineated the course of the membrane and fine-structure of mitochondria. This method allows multiplexed super-resolution imaging in large tissue volumes with a resolution three orders of magnitude better than confocal microscopy. KW - architecture KW - rat calyx KW - in-vivo KW - microscopy KW - resolution KW - proteins KW - transmission KW - ultrastructure KW - reconstruction KW - localization Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134434 VL - 7 IS - 5 ER - TY - JOUR A1 - Aso, Yoshinori A1 - Herb, Andrea A1 - Ogueta, Maite A1 - Siwanowicz, Igor A1 - Templier, Thomas A1 - Friedrich, Anja B. A1 - Ito, Kei A1 - Scholz, Henrike A1 - Tanimoto, Hiromu T1 - Three Dopamine Pathways Induce Aversive Odor Memories with Different Stability JF - PLoS Genetics N2 - Animals acquire predictive values of sensory stimuli through reinforcement. In the brain of Drosophila melanogaster, activation of two types of dopamine neurons in the PAM and PPL1 clusters has been shown to induce aversive odor memory. Here, we identified the third cell type and characterized aversive memories induced by these dopamine neurons. These three dopamine pathways all project to the mushroom body but terminate in the spatially segregated subdomains. To understand the functional difference of these dopamine pathways in electric shock reinforcement, we blocked each one of them during memory acquisition. We found that all three pathways partially contribute to electric shock memory. Notably, the memories mediated by these neurons differed in temporal stability. Furthermore, combinatorial activation of two of these pathways revealed significant interaction of individual memory components rather than their simple summation. These results cast light on a cellular mechanism by which a noxious event induces different dopamine signals to a single brain structure to synthesize an aversive memory. KW - dynamics KW - serotonin KW - expression KW - melanogaster KW - neurons form KW - olfactory memory KW - long-term-memory KW - drosophila mushroom body KW - sensitization KW - localization Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130631 VL - 8 IS - 7 ER - TY - JOUR A1 - Huser, Annina A1 - Rohwedder, Astrid A1 - Apostolopoulou, Anthi A. A1 - Widmann, Annekathrin A1 - Pfitzenmaier, Johanna E. A1 - Maiolo, Elena M. A1 - Selcho, Mareike A1 - Pauls, Dennis A1 - von Essen, Alina A1 - Gupta, Tript A1 - Sprecher, Simon G. A1 - Birman, Serge A1 - Riemensperger, Thomas A1 - Stocker, Reinhard F. A1 - Thum, Andreas S. T1 - The Serotonergic Central Nervous System of the Drosophila Larva: Anatomy and Behavioral Function JF - PLoS One N2 - The Drosophila larva has turned into a particularly simple model system for studying the neuronal basis of innate behaviors and higher brain functions. Neuronal networks involved in olfaction, gustation, vision and learning and memory have been described during the last decade, often up to the single-cell level. Thus, most of these sensory networks are substantially defined, from the sensory level up to third-order neurons. This is especially true for the olfactory system of the larva. Given the wealth of genetic tools in Drosophila it is now possible to address the question how modulatory systems interfere with sensory systems and affect learning and memory. Here we focus on the serotonergic system that was shown to be involved in mammalian and insect sensory perception as well as learning and memory. Larval studies suggested that the serotonergic system is involved in the modulation of olfaction, feeding, vision and heart rate regulation. In a dual anatomical and behavioral approach we describe the basic anatomy of the larval serotonergic system, down to the single-cell level. In parallel, by expressing apoptosis-inducing genes during embryonic and larval development, we ablate most of the serotonergic neurons within the larval central nervous system. When testing these animals for naive odor, sugar, salt and light perception, no profound phenotype was detectable; even appetitive and aversive learning was normal. Our results provide the first comprehensive description of the neuronal network of the larval serotonergic system. Moreover, they suggest that serotonin per se is not necessary for any of the behaviors tested. However, our data do not exclude that this system may modulate or fine-tune a wide set of behaviors, similar to its reported function in other insect species or in mammals. Based on our observations and the availability of a wide variety of genetic tools, this issue can now be addressed. KW - term memory KW - light avoidance KW - decision making KW - olfactory memory KW - immunoreactive neurons KW - containing neurons KW - moth manduca sexta KW - head involution KW - mushroom bodies KW - biogenic amines Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130437 VL - 7 IS - 10 ER - TY - JOUR A1 - Naseem, Muhammad A1 - Dandekar, Thomas T1 - The Role of Auxin-Cytokinin Antagonism in Plant-Pathogen Interactions JF - PLOS Pathogens N2 - No abstract available. KW - disease KW - pseudomas-syringae KW - arabidpsis thaliana KW - immunity KW - organogenesis KW - transcription KW - resistance KW - crosstalk Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131901 VL - 8 IS - 11 ER - TY - JOUR A1 - Rhiem, Kerstin A1 - Engel, Christoph A1 - Graeser, Monika A1 - Zachariae, Silke A1 - Kast, Karin A1 - Kiechle, Marion A1 - Ditsch, Nina A1 - Janni, Wolfgang A1 - Mundhenke, Christoph A1 - Golatta, Michael A1 - Varga, Dominic A1 - Preisler-Adams, Sabine A1 - Heinrich, Tilman A1 - Bick, Ulrich A1 - Gadzicki, Dorothea A1 - Briest, Susanne A1 - Meindl, Alfons A1 - Schmutzler, Rita K. T1 - The risk of contralateral breast cancer in patients from BRCA1/2 negative high risk families as compared to patients from BRCA1 or BRCA2 positive families: a retrospective cohort study JF - Breast Cancer Research N2 - Introduction: While it has been reported that the risk of contralateral breast cancer in patients from BRCA1 or BRCA2 positive families is elevated, little is known about contralateral breast cancer risk in patients from high risk families that tested negative for BRCA1/2 mutations. Methods: A retrospective, multicenter cohort study was performed from 1996 to 2011 and comprised 6,235 women with unilateral breast cancer from 6,230 high risk families that had tested positive for BRCA1 (n = 1,154) or BRCA2 (n = 575) mutations or tested negative (n = 4,501). Cumulative contralateral breast cancer risks were calculated using the Kaplan-Meier product-limit method and were compared between groups using the log-rank test. Cox regression analysis was applied to assess the impact of the age at first breast cancer and the familial history stratified by mutation status. Results: The cumulative risk of contralateral breast cancer 25 years after first breast cancer was 44.1% (95%CI, 37.6% to 50.6%) for patients from BRCA1 positive families, 33.5% (95%CI, 22.4% to 44.7%) for patients from BRCA2 positive families and 17.2% (95%CI, 14.5% to 19.9%) for patients from families that tested negative for BRCA1/2 mutations. Younger age at first breast cancer was associated with a higher risk of contralateral breast cancer. For women who had their first breast cancer before the age of 40 years, the cumulative risk of contralateral breast cancer after 25 years was 55.1% for BRCA1, 38.4% for BRCA2, and 28.4% for patients from BRCA1/2 negative families. If the first breast cancer was diagnosed at the age of 50 or later, 25-year cumulative risks were 21.6% for BRCA1, 15.5% for BRCA2, and 12.9% for BRCA1/2 negative families. Conclusions: Contralateral breast cancer risk in patients from high risk families that tested negative for BRCA1/2 mutations is similar to the risk in patients with sporadic breast cancer. Thus, the mutation status should guide decision making for contralateral mastectomy. KW - contralateral breast cancer KW - BRCA1/2 negative KW - BRCA1 positive KW - BRCA2 positive Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-135715 VL - 14 IS - 6 ER -