Johannes Gutenberg University View Institution's Website 9 articles published in JoVE Biology Transposon-insertion Sequencing as a Tool to Elucidate Bacterial Colonization Factors in a Burkholderia gladioli Symbiont of Lagria villosa Beetles Ramya Ganesan1, Martin Kaltenpoth1,2, Laura V. Flórez1,3 1Department of Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, 2Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 3Department of Plant and Environmental Sciences, Section for Organismal Biology, University of Copenhagen This is an adapted method for identifying candidate insect colonization factors in a Burkholderia beneficial symbiont. The beetle host is infected with a random mutant library generated via transposon mutagenesis, and library complexity after colonization is compared to a control grown in vitro. Chemistry Microfluidic Preparation of Liquid Crystalline Elastomer Actuators Tristan Hessberger*1, Lukas B. Braun*1, Christophe A. Serra2, Rudolf Zentel1 1Department of Organic Chemistry, Johannes Gutenberg University, 2CNRS, ICS UPR 22, Université de Strasbourg This article describes the microfluidic process and parameters to prepare actuating particles from liquid crystalline elastomers. This process allows the preparation of actuating particles and the variation of their size and shape (from oblate to strongly prolate, core-shell, and Janus morphologies) as well as the magnitude of actuation. Cancer Research Therapy Testing in a Spheroid-based 3D Cell Culture Model for Head and Neck Squamous Cell Carcinoma Jan Hagemann*1, Christian Jacobi*2, Sabine Gstoettner3, Christian Welz4, Sabina Schwenk-Zieger3, Roland Stauber1, Sebastian Strieth1, Julian Kuenzel1, Philipp Baumeister3, Sven Becker1,3 1Department of Otorhinolaryngology, Johannes-Gutenberg University Medical Center, 2Department of Otorhinolaryngology, Technical University of Munich Medical Center, 3Department of Otorhinolaryngology, Ludwig-Maximilian-University Medical Center, 4Department of Otorhinolaryngology, University of Goettingen Medical Center We describe the evolution of a spheroid-based, three-dimensional in vitro model that enables us to test the current standard of experimental therapy regimens for head and neck squamous cell carcinoma on cell lines, aiming at evaluating therapy susceptibility and resistance on primary cells from human specimens in the future. Behavior Introducing Clicker Training as a Cognitive Enrichment for Laboratory Mice Charlotte Leidinger1,2, Felix Herrmann1, Christa Thöne-Reineke*2, Nadine Baumgart*1, Jan Baumgart*1 1Translational Animal Research Center, University Medical Centre, Johannes Gutenberg-Universität Mainz, 2Department of Veterinary Medicine, Institute of Animal Welfare, Animal Behavior and Laboratory Animal Science, Freie Universität Berlin The development of new refinement strategies for laboratory mice is a challenging task that contributes towards fulfilling the 3R principle. This protocol introduces clicker training as a cognitive enrichment program for laboratory mice. Bioengineering Wet Chemistry and Peptide Immobilization on Polytetrafluoroethylene for Improved Cell-adhesion Matthias Gabriel1, Kerstin Niederer2, Holger Frey2 1Sidra Cardiovascular Research, 2Department of Organic Chemistry, Johannes-Gutenberg University Cell-adhesiveness is key to many approaches in biomaterial research and tissue engineering. A step-by-step technique is presented using wet-chemistry for the surface modification of the important polymer PTFE with peptides. Medicine Evaluation of Planar-Cell-Polarity Phenotypes in Ciliopathy Mouse Mutant Cochlea Helen May-Simera1 1Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg-Universität Mainz Primary cilia influence various signaling pathways. The mammalian cochlea is ideal for examining planar cell polarity (PCP) signaling. Cilia dysfunction affects cochlear outgrowth, cellular patterning and hair cell orientation, readouts of PCP. Our goal is to analyze PCP signaling in mouse cochlea via phenotypic analysis, immunohistochemistry and scanning electron microscopy. Neuroscience Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster Christof Rickert1, Thomas Kunz1, Kerri-Lee Harris2, Paul Whitington2, Gerhard Technau1 1Institute of Genetics, University of Mainz, 2Department of Anatomy and Neuroscience, University of Melbourne We present a technique for labeling single neurons in the central nervous system (CNS) of Drosophila embryos, which allows the analysis of neuronal morphology by either transmitted light or confocal microscopy. Immunology and Infection In vitro tRNA Methylation Assay with the Entamoeba histolytica DNA and tRNA Methyltransferase Dnmt2 (Ehmeth) Enzyme Ayala Tovy1, Benjamin Hofmann2, Mark Helm2, Serge Ankri1 1Faculty of Medicine, Rappaport Institute, Technion - Israel Institute of Technology, 2The Pharmacy and Biochemistry Institute, Johannes Gutenberg University This protocol describes the preparation of a synthetic tRNA substrate for the Entamoeba histolytica DNA/tRNA methyltransferase 2 (Dnmt2) homolog Ehmeth and the measure of its methyltransferase activity. This experimental approach can be used for investigating the activity of other Dnmt2 proteins. Biology Homemade Site Directed Mutagenesis of Whole Plasmids Mark Laible1, Kajohn Boonrod2 1Department of Biology, Johannes Gutenberg-University Mainz, Germany, 2Proteomics division, AlPlanta, Neustadt an der Weinstrasse, Germany Site directed mutagenesis of whole plasmids is a simple way to create slightly different variations of an original plasmid. Here we demonstrate an easy and cost effective way to introduce base substitutions into a plasmid using standard reagents.