Fakultät für Biologie - Digitale Hochschulschriften der LMU - Teil 05/06

Signal transduction mechanisms and wiring specificity of bce-type antimicrobial peptide sensing and detoxification modules in firmicutes

Classification and functional characterization of extracytoplasmic function (ECF) σ factors from planctomycetes and actinobacteria

Bacteria necessitate multiple signal transduction systems to sense the ever-changing environments and mediate the cellular response accordingly. The major bacterial signal transduction systems are one-component system (1CS), two-component system (2CS) and extracytoplasmic function (ECF) σ factor. Compared to 1CSs and 2CSs, ECF σ factors have only been identified much later and therefore the knowledge about their molecular mechanisms and physiological roles is less profound. This thesis mainly fo...

Diversity, molecular phylogeny, ecology and distribution of the genera Lactifluus and Lactarius (Russulales, Basidiomycota) in West Africa

Breaking symmetry

Polarity is a fundamental feature of almost all cells. It generally refers to the asymmetric organization of several cellular components. The plasma membrane, for example, exhibits both a transbilayer and a lateral asymmetry in most eukaryotic cells. Lipids are asymmetrically distributed between the cytoplasmic and the extracellular leaflet of the membrane and segregate laterally together with specific proteins to form dynamic nanoscale assemblies, known as rafts. Polarity can also specifically ...

Untersuchung der gesteigerten Zytotoxizität von Trabectedin durch Hyperthermie in Tumorzellen

Adulte Weichgewebesarkome (engl. soft tissue sarcoma; STS) werden zu einer Gruppe seltener maligner und teilweise aggressiver Tumoren klassifiziert, die eine Tendenz zur Bildung von hämatogenen Fernmetastasen aufweisen. Die Kombination der Regionalen Hyperthermie mit einer Chemotherapie erwies sich in vorangegangenen Studien als eine vielversprechende Behandlungsoption beim lokalisierten Hochrisiko STS. Es wurde gezeigt, dass eine neoadjuvante Chemotherapie mit Regionaler Hyperthermie bei diesen...

Testing traditional concepts

The phylotypic stage of Zebrafish

The phylotypic stage, as part of the embryonic period, is the stage where embryos of different species of a phylum show a high degree of similarity. Johann Friedrich Meckel, Karl Ernst von Baer and Ernst Haeckel already described it for vertebrates in the 19th century. They observed that vertebrate embryos pass through a period of morphological similarity. Since then, scientists have researched the field of the phylotypic stage and it was subject of many controversial discussions. The name “phyl...

Immunmodulatorische Aktivität von Überständen probiotischer Bakterien und dem darin enthaltenen D-Tryptophan

Multi-level variation in labile characters

Labile characters, like behaviors, are phenotypes that are expressed repeatedly in the life of an individual. These types of characters allow individuals to adjust their phenotype to various levels of environmental variation, and therefore play a key role in the evolutionary process. Labile phenotypes are distinct because of their multi-level nature; individuals can differ in their average phenotypic expression (causing among-individual variation), but they can also vary their phenotype in each ...

Phenotypic, environmental, and genetic variation as sources of intraspecific differences in behavioral sleep in wild great tits (Parus major)

Single-cell plasticity in mouse visual cortex following retinal lesions

Functional characterisation and Mutational analysis of a bacterial dynamin-like protein, DynA

Membrane remodeling is a dynamic process that occurs in bacterial cells to facilitate substrate transport and to provide protection to bacteria during environmental stress. In eukaryotic cells, membrane remodeling is carried out by dynamin-like proteins (DLPs). These proteins are involved in diverse membrane-associated functions such as cargo transport via vesicles, cytokinesis, division of cell organelles and resistance to pathogens. DLPs are also conserved in bacterial species; however, their ...

Eph-Rezeptoren, Ephrine und Notch bei der Ausbildung von Gewebegrenzen in Hydra

Architecture of SMC-kleisin complexes

In all cellular systems, the transmission of bulk genetic information during proliferation occurs in the form of chromosomes. The segregation of these entities upon cell division is of pivotal importance for all forms of life. Structural maintenance of chromosomes (SMC)-kleisin complexes are ubiquitous and essential factors that ensure proper organisation and segregation of the genetic material. Aim of this work was to elucidate evolutionary conserved features in the architecture of SMC-kleisin ...

Triops-induced morphological defences in Daphnia magna

Stimulus-dependent glucocorticoid receptor signalling in early-life stressed mice

Epigenetic programming facilitates the adaptation of an organism to changes in the environment through lasting alterations in gene expression that underlie certain physical and behavioral phenotypes. Exposure to adverse events in early postnatal life is known to increase the risk for stress-related psychiatric disorders later on. Our previous studies showed that early-life stress (ELS) in mice caused by periodic infant-mother separation (MS) leads to increased hyperactivity of the HPA axis, redu...

Characterization of the Dpb11-Slx4 Complex and its role in DNA repair

Genetics of human sleep EEG

Sleep characteristics are candidates for predictive biological markers in patients with severe psychiatric diseases, in particular affective disorder and schizophrenia. The genetic components of sleep determination in humans remain, to a large degree, unelucidated. In particular, the heritability of rapid eye movement (REM) sleep and EEG bursts of oscillatory brain activity in Non-REM sleep, i.e. sleep spindles, are of interest. In addition, recent findings suggest a strong role of distinct slee...

Strukturelle und funktionale Analyse der Effektordomäne des pH-abhängigen Einkomponentensystems CadC in Escherichia coli

Das Einkomponentensystem CadC in Escherichia coli zählt zur Gruppe der ToxR-ähnlichen Transkriptionsregulatoren und aktiviert bei niedrigem pH-Wert die Expression des cadBA-Operons, einem Säure-induzierbaren Lysin-Decarboxylase-System. Transkriptionsregulatoren der ToxR-Familie zeichnen sich durch einen gemeinsamen modularen Aufbau aus und bestehen aus einer periplasmatischen Sensordomäne, einer Transmembranhelix und einer zytoplasmatischen Effektordomäne. Die Signalwahrnehmung, -weiterleitung u...

Charakterisierung interindividueller Strahlenempfindlichkeit in Zellen aus Tumorpatienten

Die Strahlenempfindlichkeit des Normalgewebes ist in der humanen Bevölkerung sehr heterogen und kann bislang nicht über prädiagnostische Biomarker charakterisiert werden. Im Rahmen der vorliegenden Arbeit wurde ein Verfahren entwickelt, um die Strahlenempfindlichkeit in lymphoblastoiden Zelllinien von jungen Lungenkrebspatienten in einem Hochdurchsatz Screening-Ansatz zu untersuchen. Fünf Zelllinien mit unterschiedlicher Strahlenempfindlichkeit wurden gewählt, um in einem ungerichteten Versuchsa...

Biofilm formation of the quorum sensing model organism Vibrio harveyi

Proliferation and arrest of human tetraploid cells

Durch Fehler entstandene tetraploide Zellen sind chromosomal instabil und können zu Zelltransformation führen. Die Beweise verdichten sich, dass die Propagation von tetraploiden Säugetierzellen durch einen p53-vermittelten Arrest eingeschränkt wird; jedoch ist weiterhin unklar, was die Ursache dieses p53-vermittelten Arrests ist. Um die Ursache des p53-vermittelten Arrests zu identifizieren, wurden individuelle Zellen mittels zeitraffender Mikroskopie in Echtzeit verfolgt. Neu entstandene tetrap...

Natural history, taxonomy, biogeography and genome evolution of the worldwide endoparasite family Apodanthaceae (Cucurbitales)

Lokalisierung und Charakterisierung Calmodulin-ähnlicher Proteine aus Arabidopsis thaliana

Genomweite Assoziationsstudien mit metabolischen Merkmalen aus Kernspinresonanz (NMR) Spektroskopie

Real-time imaging of hippocampal network dynamics reveals trisynaptic induction of CA1 LTP and "circuit-level" effects of chronic stress and antidepressants

Today’s pervasive presence of stress renders stress-related psychiatric disorders (SRPDs), a relevant global health problem. Memory impairment is a major symptom likely mediated by the hippocampus (HIP), a limbic brain region highly vulnerable to stress. Recent evidence suggests that information processing problems within specific neuronal networks might underlie SRPDs. However, the precise functional neurocircuitry that mediates hippocampal CA1 long-term potentiation (LTP), a putative correlate...

RNA-Seq-basierte Isolierung des Resistenzgens Bs4C aus Paprika

Das Paprika Resistenzgen Bs4C aus Capsicum pubescens vermittelt Resistenz gegenüber Xanthomonas campestris pv. vesicatoria (Xcv)-Stämmen, die den (transcription activator-like) TAL-Effektor AvrBs4 exprimieren. Vorangegangene Arbeiten ließen vermuten, dass AvrBs4 die Expression von Bs4C transkriptionell induziert. In einem “proof of principle”-Experiment, wurde Bs4C unter Verwendung eines RNA-Seq-basierten Ansatzes isoliert. Unter 68 differentiell AvrBs4-induzierten Paprikagenen war jedoch nur ei...

Engineering and screening of genetically encoded FRET Calcium indicators

Fluorescent protein sensors have gained great importance in research as they exhibit a number of advantages over synthetic dyes. They can be targeted precisely, large populations of cells can be imaged simultaneously, and they allow for chronic imaging approaches. Many of them however still suffer from comparably low signal changes. Improving fluorescent protein sensors can be tedious and time-consuming. For this reason, great efforts have been made not only to improve existing sensors, but also...

Optimierung der Identifizierungsstrategie von Proteinsignaturen aus Gewebe und Plasma

Funktionelle Analyse der PCNA-Polyubiquitinierung und der E3-Ligase SHPRH