@article{ZhangSiPahl2012, author = {Zhang, Shaowu and Si, Aung and Pahl, Mario}, title = {Visually guided decision making in foraging honeybees}, series = {Frontiers in Neuroscience}, volume = {6}, journal = {Frontiers in Neuroscience}, number = {88}, doi = {10.3389/fnins.2012.00088}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-124228}, year = {2012}, abstract = {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.}, language = {en} } @phdthesis{Nguyen2012, author = {Nguyen, Hoang Duong}, title = {Vaccinia virus mediated expression of human erythropoietin in colonized human tumor xenografts results in faster tumor regression and increased red blood cell biogenesis in mice}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85383}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {Cancer-related anemia is prevalent in cancer patients. Anemia negatively affects normal mental and physical function capacity with common symptoms s like fatigue, headache, or depression. Human erythropoietin (hEPO), a glycoprotein hormone regulating red blood cell formation, is approved for the treatment of cancer-related anemia. It has shown benefits in correcting anemia, and subsequently improving health-related quality of life and/or enhancing radio-, and chemotherapy. Several recent clinical trials have suggested that recombinant hEPO (rhEPO) may promote tumor growth that raises the questions concerning the safety of using rhEPO for cancer treatment. However in others, such effects were not indicated. As of today, the direct functional effect of rhEPO in tumor models remains controversial and needs to be further analyzed. Based on the GLV-1h68 backbone, the hEPO-expressing recombinant VACV strains (EPO-VACVs) GLV-1h210, GLV-1h211, GLV-1h212 and GLV-1h213 were generated by replacing the lacZ expression cassette at the J2R locus with hEPO under the control of different vaccinia promoters p7.5, pSE, pSEL, pSL, respectively. Also, GLV-1h209 was generated, which is similar to GLV-1h210 but expresses a mutated non-functinal EPO (R103A). The EPO-VACV strains were characterized for their oncolytic efficacy in lung (A549) cancer cells in culture and tumor xenografts. Concomitantly, the effects of locally expressed hEPO in tumors on virus replication, host immune infiltration, tumor vascularization and tumor growth were also evaluated. As expected, EPO-VACVs enhanced red blood cell (RBC) formation in xenograft model. The number of RBCs and hemoglobin (Hb) levels were significantly increased in EPO-VACVs-treated mice compared to GLV-1h68-treated or untreated control mice. However, the mean size of RBC or Hb content per RBC remained normal. Furthermore, over-expression of hEPO did not significantly affect numbers of lymphocytes, monocytes, leucocytes or platelets in the peripheral blood stream. The expression of hEPO in colonized tumors of mice treated with EPO-VACVs was demonstrated by immunohistological staining. Interestingly, there were 9 - 10 hEPO isoforms detected either in tumors, cells, or supernatant, while 3-4 basic isoforms were missing in blood serum, where only six hEPO isoforms were found. Tumor-bearing mice after treatment with EPO-VACVs showed enhanced tumor regression compared to GLV-1h68. The virus titers in tumors in EPO-VACVs-treated mice were 3-4 fold higher compared to GLV-1h68-treated mice. Nevertheless, no significant difference in virus titers among EPO-VACVs was found. The blood vessels in tumors were significantly enlarged while the blood vessel density remained unchanged compared to the GLV-1h68 treated mice, indicating that hEPO did not affect endothelial cell proliferation in this model. Meanwhile, rhEPO (Epoetin alfa) alone or in combination with GLV-1h68 did not show any signs of enhanced tumor growth when compared to untreated controls and GLV-1h68 groups, while doses used were clinical relevant (500 U/kg). These findings suggested that hEPO did not promote angiogenesis or tumor growth in the A549 tumor xenograft model. Human EPO has been reported to function as an immune modulator. In this study, however, we did not find any involvement of hEPO in immune cytokine and chemokine expression or innate immune cell infiltration (leucocytes, B cells, macrophages and dendritic cells) into infected tumors. The degree of immune infiltration and cytokine expression was directly correlated to the number of virus particles. Increased virus replication, led to more recruited immune cells and secreted cytokines/chemokines. It was proposed that tumor regression was at least partially mediated through activation of innate immune mechanisms. In conclusion, the novel EPO-VACVs were shown to significantly increase the number of RBCs, Hb levels, and virus replication in tumors as well as to enhance tumor regression in the A549 tumor xenograft model. Moreover, locally expressed hEPO did not promote tumor angiogenesis, tumor growth, and immune infiltration but was shown to causing enlarged tumoral microvessels which facilitated virus spreading. It is conceivable that in a possible clinical application, anemic cancer patients could benefit from the EPO-VACVs, where they could serve as "wellness pills" to decrease anemic symptoms, while simultaneously destroying tumors.}, subject = {Erythropoietin}, language = {en} } @article{HeddergottKruegerBabuetal.2012, author = {Heddergott, Nico and Kr{\"u}ger, Timothy and Babu, Sujin B. and Wei, Ai and Stellamanns, Erik and Uppaluri, Sravanti and Pfohl, Thomas and Stark, Holger and Engstler, Markus}, title = {Trypanosome Motion Represents an Adaptation to the Crowded Environment ofthe Vertebrate Bloodstream}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78421}, year = {2012}, abstract = {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}, subject = {Biologie}, language = {en} } @article{HeddergottKruegerBabuetal.2012, author = {Heddergott, Niko and Kr{\"u}ger, Timothy and Babu, Sujin B. and Wei, Ai and Stellamanns, Erik and Uppaluri, Sravanti and Pfohl, Thomas and Stark, Holger and Engstler, Markus}, title = {Trypanosome Motion Represents an Adaptation to the Crowded Environment of the Vertebrate Bloodstream}, series = {PLoS Pathogens}, volume = {8}, journal = {PLoS Pathogens}, number = {11}, doi = {10.1371/journal.ppat.1003023}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134595}, pages = {e1003023}, year = {2012}, abstract = {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.}, language = {en} } @article{SchmittBackesNourkamiTutdibietal.2012, author = {Schmitt, Jana and Backes, Christina and Nourkami-Tutdibi, Nasenien and Leidinger, Petra and Deutscher, Stephanie and Beier, Markus and Gessler, Manfred and Graf, Norbert and Lenhof, Hans-Peter and Keller, Andreas and Meese, Eckart}, title = {Treatment-independent miRNA signature in blood of wilms tumor patients}, series = {BMC Genomics}, volume = {13}, journal = {BMC Genomics}, number = {379}, doi = {10.1186/1471-2164-13-379}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-124034}, year = {2012}, abstract = {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.}, language = {en} } @article{FoersterBeisserGrohmeetal.2012, author = {F{\"o}rster, Frank and Beisser, Daniela and Grohme, Markus A. and Liang, Chunguang and Mali, Brahim and Siegl, Alexander Matthias and Engelmann, Julia C. and Shkumatov, Alexander V. and Schokraie, Elham and M{\"u}ller, Tobias and Schn{\"o}lzer, Martina and Schill, Ralph O. and Frohme, Marcus and Dandekar, Thomas}, title = {Transcriptome analysis in tardigrade species reveals specific molecular pathways for stress adaptations}, series = {Bioinformatics and biology insights}, volume = {6}, journal = {Bioinformatics and biology insights}, doi = {10.4137/BBI.S9150}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123089}, pages = {69-96}, year = {2012}, abstract = {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.}, language = {en} } @article{NanguneriFlottmannHorstmannetal.2012, author = {Nanguneri, Siddharth and Flottmann, Benjamin and Horstmann, Heinz and Heilemann, Mike and Kuner, Thomas}, title = {Three-Dimensional, Tomographic Super-Resolution Fluorescence Imaging of Serially Sectioned Thick Samples}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {5}, doi = {10.1371/journal.pone.0038098}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134434}, pages = {e38098}, year = {2012}, abstract = {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.}, language = {en} } @article{AsoHerbOguetaetal.2012, author = {Aso, Yoshinori and Herb, Andrea and Ogueta, Maite and Siwanowicz, Igor and Templier, Thomas and Friedrich, Anja B. and Ito, Kei and Scholz, Henrike and Tanimoto, Hiromu}, title = {Three Dopamine Pathways Induce Aversive Odor Memories with Different Stability}, series = {PLoS Genetics}, volume = {8}, journal = {PLoS Genetics}, number = {7}, doi = {10.1371/journal.pgen.1002768}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130631}, pages = {e1002768}, year = {2012}, abstract = {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.}, language = {en} } @article{HuserRohwedderApostolopoulouetal.2012, author = {Huser, Annina and Rohwedder, Astrid and Apostolopoulou, Anthi A. and Widmann, Annekathrin and Pfitzenmaier, Johanna E. and Maiolo, Elena M. and Selcho, Mareike and Pauls, Dennis and von Essen, Alina and Gupta, Tript and Sprecher, Simon G. and Birman, Serge and Riemensperger, Thomas and Stocker, Reinhard F. and Thum, Andreas S.}, title = {The Serotonergic Central Nervous System of the Drosophila Larva: Anatomy and Behavioral Function}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {10}, doi = {10.1371/journal.pone.0047518}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130437}, pages = {e47518}, year = {2012}, abstract = {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.}, language = {en} } @article{NaseemDandekar2012, author = {Naseem, Muhammad and Dandekar, Thomas}, title = {The Role of Auxin-Cytokinin Antagonism in Plant-Pathogen Interactions}, series = {PLOS Pathogens}, volume = {8}, journal = {PLOS Pathogens}, number = {11}, doi = {10.1371/journal.ppat.1003026}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131901}, pages = {e1003026}, year = {2012}, abstract = {No abstract available.}, language = {en} }