The present article describes the steps required to isolate and characterize RNA polymerase fidelity variants of RNA viruses and how to use mutation frequency data to confirm fidelity changes in tissue culture.
1Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 2Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa
Disease-causing mutations in actin can alter cytoskeletal function. Cytoskeletal dynamics are quantified through imaging of fluorescently tagged proteins using total internal fluorescence microscopy. As an example, the cytoskeletal protein, Aip1p, has altered localization and movement in cells expressing the mutant actin isoform, R256H.
Primary Orthotopic Glioma Xenografts Recapitulate Infiltrative Growth and Isocitrate Dehydrogenase I Mutation
1Department of Neurology, Vanderbilt University Medical Center, 2Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, 3Neurology Service, Veteran Affairs TVHS
Malignant gliomas constitute a heterogeneous group of highly infiltrative glial neoplasms with distinct clinical and molecular features. Primary orthotopic xenografts recapitulate the histopathological and molecular features of malignant glioma subtypes in preclinical animal models.
Combining Magnetic Sorting of Mother Cells and Fluctuation Tests to Analyze Genome Instability During Mitotic Cell Aging in Saccharomyces cerevisiae
1Department of Biological Sciences, Rensselaer Polytechnic Institute
Mutation rates in young Saccharomyces cerevisiae cells measured through fluctuation tests are used to predict mutation frequencies for mother cells of different replicative ages. Magnetic sorting and flow cytometry are then used to measure actual mutation frequencies and age of mother cells to identify any deviations from predicted mutation frequencies.
We developed computational de novo protein design methods capable of tackling several important areas of protein design. To disseminate these methods we present Protein WISDOM, an online tool for protein design (http://www.proteinwisdom.org). Starting from a structural template, design of monomeric proteins for increased stability and complexes for increased binding affinity can be performed.…
Published July 25, 2013. Keywords: Genetics, Molecular Biology, Bioengineering, Biochemistry, Biomedical Engineering, Chemical Engineering, Computational Biology, Genomics, Proteomics, Protein, Protein Binding, Computational Biology, Drug Design, optimization (mathematics), Amino Acids, Peptides, and Proteins, De novo protein and peptide design, Drug design, In silico sequence selection, Optimization, Fold specificity, Binding affinity, sequencing
1Environmental Health Science and Research Bureau, Health Canada, Environmental Health Centre
De novo mutations in the male germline may contribute to adverse health outcomes in subsequent generations. Here we describe a protocol for the use of a transgenic rodent model for quantifying mutations in male germ cells induced by environmental agents.
Published August 6, 2014. Keywords: Genetics, sperm, spermatogonia, male germ cells, spermatogenesis, de novo mutation, OECD TG 488, transgenic rodent mutation assay, N-ethyl-N-nitrosourea, genetic toxicology
1Greehey Children's Cancer Research Institute, UT Health Science Center at San Antonio, 2Department of Cellular and Structural Biology, UT Health Science Center at San Antonio, 3Department of Pathology, UT Health Science Center at San Antonio, 4Department of Microbiology, UT Health Science Center at San Antonio, 5Cancer Therapy and Research Center, UT Health Science Center at San Antonio
Here we describe an in vivo mutagenesis assay for small numbers of purified hematopoietic cells using the LacI transgenic mouse model. The LacI gene can be isolated to determine the frequency, location, and type of DNA mutants spontaneously arisen or after exposure to genotoxins.
Investigating Protein-protein Interactions in Live Cells Using Bioluminescence Resonance Energy Transfer
1Language and Genetics Department, Max Planck Institute for Psycholinguistics, 2Donders Institute for Brain, Cognition and Behaviour
Interactions between proteins are fundamental to all cellular processes. Using Bioluminescence Resonance Energy Transfer, the interaction between a pair of proteins can be monitored in live cells and in real time. Furthermore, the effects of potentially pathogenic mutations can be assessed.
A novel directed evolution method specific to the field of thermostability engineering was developed and consequently validated for bacteriolytic enzymes. After only one round of random mutagenesis, an evolved bacteriolytic enzyme, PlyC 29C3, displayed greater than twice the residual activity when compared to the wild-type protein after elevated temperature incubation.
Published November 7, 2012. Keywords: Immunology, Molecular Biology, Genetics, Microbiology, directed evolution, thermal behavior, thermostability, endolysin, enzybiotic, bacteriolytic, antimicrobial, therapeutic, PlyC
1Department of Pharmacy and Biotechnology, University of Bologna, 2CSGI, Department of Chemistry, University of Firenze
Protein co-expression is a powerful alternative to the reconstitution in vitro of protein complexes, and is of help in performing biochemical and genetic tests in vivo. Here we report on the use of protein co-expression in Escherichia coli to obtain protein complexes, and to tune the mutation frequency of cells.
Here we demonstrate a simple protocol to create a random mutant library for a given target sequence. We show how this method, which is performed in vivo in Escherichia coli, can be coupled with functional selections to evolve new enzymatic activities.
Published March 16, 2011. Keywords: Genetics, random mutagenesis, directed evolution, LB agar drug gradient, bacterial complementation, ColE1 plasmid, DNA polymerase I, replication fidelity, genetic adaptation, antimicrobials, methylating agents
1Department of Physics and Astronomy, VU University Amsterdam
This protocol details the reconstitution of light-harvesting complexes in vitro. These integral membrane proteins coordinate chlorophylls and carotenoids and are responsible for harvesting light in higher plants and green algae.
Pairwise Growth Competition Assay for Determining the Replication Fitness of Human Immunodeficiency Viruses
1Department of Microbiology, University of Washington, 2Departments of Medicine and Laboratory Medicine, University of Washington, 3U.S Military HIV Research Program, Walter Reed Army Institute of Research, 4Henry M. Jackson Foundation
Growth competition between nearly isogenic viruses provides a sensitive measurement for determining relative replication fitness. The protocols described here include the construction of recombinant HIV-1 clones, virus propagation and growth competition and analysis methods optimized to yield sensitive and consistent results.
Monitoring Intraspecies Competition in a Bacterial Cell Population by Cocultivation of Fluorescently Labelled Strains
1Department of General Microbiology, Georg-August University
Bacteria may accumulate either detrimental or beneficial mutations during their lifetime. In a population of cells individuals that have accumulated beneficial mutations may rapidly outcompete their fellows. Here we present a simple procedure to visualize intraspecies competition in a bacterial cell population over time using fluorescently labeled individuals.
Published January 18, 2014. Keywords: Cellular Biology, Bacillus subtilis, evolution, adaptation, selective pressure, beneficial mutation, intraspecies competition, fluorophore-labelling, Fluorescence Microscopy
1Akonni Biosystems, Inc.
An amplification microarray combines asymmetric PCR amplification and microarray hybridization into a single chamber, which significantly streamlines microarray workflow for the end user. Simplifying microarray workflow is a necessary first step for creating microarray-based diagnostics that can be routinely used in lower-resource environments.
A Restriction Enzyme Based Cloning Method to Assess the In vitro Replication Capacity of HIV-1 Subtype C Gag-MJ4 Chimeric Viruses
1Emory Vaccine Center at Yerkes National Primate Research Center, Emory University, 2Department of Pathology and Laboratory Medicine, Emory University
HIV-1 pathogenesis is defined by both viral characteristics and host genetic factors. Here we describe a robust method that allows for reproducible measurements to assess the impact of the gag gene sequence variation on the in vitro replication capacity of the virus.
gDNA Enrichment by a Transposase-based Technology for NGS Analysis of the Whole Sequence of BRCA1, BRCA2, and 9 Genes Involved in DNA Damage Repair
1Department of Biology and Pathology of Tumors, Unit of Molecular Biology, Platform of Immunomonitoring and Genetics, Centre Georges-François Leclerc
gDNA enrichment for NGS sequencing is an easy and powerful tool for the study of constitutional mutations. In this article, we present the procedure to analyse simply the complete sequence of 11 genes involved in DNA damage repair.
Using Caenorhabditis elegans as a Model System to Study Protein Homeostasis in a Multicellular Organism
1Department of Life Sciences, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev
To study the relationship between protein homeostasis, stress and aging, we monitored changes in protein folding by following protein dysfunction, protein localization in the cell and protein stability at the organismal, cellular and protein levels, using the genetically tractable metazoan Caenorhabditis elegans as a model system.
Published December 18, 2013. Keywords: Biochemistry, aging, Caenorhabditis elegans, heat shock response, neurodegenerative diseases, protein folding homeostasis, proteostasis, stress, temperature-sensitive
Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays
1Department of Molecular Genetics, University of Toronto, 2Banting and Best Department of Medical Research, Donnelly Centre, University of Toronto, 3Department of Biochemistry, Research and Innovation Centre, University of Regina
Systematic, large-scale synthetic genetic (gene-gene or epistasis) interaction screens can be used to explore genetic redundancy and pathway cross-talk. Here, we describe a high-throughput quantitative synthetic genetic array screening technology, termed eSGA that we developed for elucidating epistatic relationships and exploring genetic interaction networks in Escherichia coli.…
Published November 12, 2012. Keywords: Genetics, Molecular Biology, Medicine, Biochemistry, Microbiology, Aggravating, alleviating, conjugation, double mutant, Escherichia coli, genetic interaction, Gram-negative bacteria, homologous recombination, network, synthetic lethality or sickness, suppression
Detecting Somatic Genetic Alterations in Tumor Specimens by Exon Capture and Massively Parallel Sequencing
1Department of Pathology, Memorial Sloan-Kettering Cancer Center, 2Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center
We describe the preparation of barcoded DNA libraries and subsequent hybridization-based exon capture for detection of key cancer-associated mutations in clinical tumor specimens by massively parallel "next generation" sequencing. Targeted exon sequencing offers the benefits of high throughput, low cost, and deep sequence coverage, thus yielding high sensitivity for detecting low frequency mutations.…
Published October 18, 2013. Keywords: Molecular Biology, Molecular Diagnostic Techniques, High-Throughput Nucleotide Sequencing, Genetics, Neoplasms, Diagnosis, Massively parallel sequencing, targeted exon sequencing, hybridization capture, cancer, FFPE, DNA mutations
1Department of Biological Science, Florida State University, 2Department of Biology and Biochemistry, Biology of Behavior Institute, University of Houston
Drosophila has emerged as a significant model system for dissecting the cellular and molecular underpinnings of behavioral responses to alcohol. Here we present a protocol for the collection of alcohol sensitivity data in a circadian context that can be easily applied to other experiments and is well-suited for undergraduate research.
1Divisions of Experimental Hematology and Cancer Pathology, Cancer Blood Disease Institute, Cincinnati Children's Hospital Medical Center
Emergence of genetic resistance against kinase inhibitor therapy poses significant challenge for effective cancer therapy. Identification and characterization of resistant mutations against a newly developed drug helps in better clinical management and next generation drug design. Here, we describe our protocol for in vitro screening and validation of resistant mutations.…
Growth-based Determination and Biochemical Confirmation of Genetic Requirements for Protein Degradation in Saccharomyces cerevisiae
1Department of Biology, Ball State University, 2Division of Nephrology, Cincinnati Children's Hospital
This article describes a yeast growth-based assay for the determination of genetic requirements for protein degradation. It also demonstrates a method for rapid extraction of yeast proteins, suitable for western blotting to biochemically confirm degradation requirements. These techniques can be adapted to monitor degradation of a variety of proteins.
Published February 16, 2015. Keywords: Molecular Biology, Ubiquitin-proteasome system, Saccharomyces cerevisiae, budding yeast, growth assay, protein extracts, western blotting, yeast genetics, mutants, endoplasmic reticulum-associated degradation, protein degradation
Functional Reconstitution and Channel Activity Measurements of Purified Wildtype and Mutant CFTR Protein
1Programme in Molecular Structure and Function, Hospital for Sick Children, 2Department of Biochemistry, University of Toronto, 3Department of Physiology, University of Toronto
Described here is a rapid and effective procedure for functional reconstitution of purified wild-type and mutant CFTR protein that preserves activity for this chloride channel, which is defective in Cystic Fibrosis. Iodide efflux from reconstituted proteoliposomes mediated by CFTR allows studies of channel activity and the effects of small molecules.
Generation of RNA/DNA Hybrids in Genomic DNA by Transformation using RNA-containing Oligonucleotides
This work shows how to form an RNA/DNA hybrid at the chromosomal level and reveal transfer of genetic information from RNA to genomic DNA in yeast cells.
We will demonstrate how to study the effect of a single point mutation on the function of an ion channel.
1Genetics and Biochemistry Branch of the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health
This article illustrates the use of pulse-chase radio labeling in combination with site-specific photocrosslinking to monitor interactions between a protein of interest and other factors in E. coli. Unlike traditional chemical cross-linking methods, this approach generates high resolution “snapshots” of an ordered assembly pathway in a living cell.
1Department of Biological Sciences, University of Notre Dame
The zebrafish is a powerful model system for developmental biology and human disease research due to their genetic similarity with higher vertebrates. This protocol describes a methodology to create haploid zebrafish embryos that can be utilized for forward screen strategies to identify recessive mutations in genes essential for early embryogenesis.
1Center for Human Disease Modeling, Department of Cell Biology, Duke University Medical Center, 2Department of Evolutionary Anthropology, Duke University, 3Department of Pediatrics, Duke University Medical Center
Here, we present a systematic approach for developing physiologically relevant, sensitive and specific in vivo assays for interpreting variation in human pathology. Transient genetic manipulation via microinjection of WT and mutant human mRNA and morpholino (MO) antisense oligonucleotides harness the tractability of the developing zebrafish embryo to rapidly assay pathogenic mutations, especially, but not exclusively, in the context of human developmental disorders.…
Published August 24, 2013. Keywords: Molecular Biology, Genetics, Biomedical Engineering, Medicine, Developmental Biology, Biochemistry, Anatomy, Physiology, Bioengineering, Genomics, Medical, zebrafish, in vivo, morpholino, human disease modeling, transcription, PCR, mRNA, DNA, Danio rerio, animal model
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.
Real-time Imaging of Myeloid Cells Dynamics in ApcMin/+ Intestinal Tumors by Spinning Disk Confocal Microscopy
1Department of Oncology, INSERM U661, Functional Genomic Institute, 2Department of Anatomy, University of California
By using transgenic reporter mice and injectable fluorescent labels, long-term intravital spinning disk confocal microscopy enables direct visualization of myeloid cell behavior into intestinal adenoma in the ApcMin/+ colorectal cancer model.
1Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, 2Department of Neurobiology and Anatomy, University of Utah School of Medicine, 3Interdepartmental Program in Neurosciences, University of Utah School of Medicine, 4Mutation Generation and Detection Core, HSC Core Research Facility, University of Utah School of Medicine, 5Department of Neurology, University of Utah School of Medicine
PCR combined with high-resolution melt analysis (HRMA) is demonstrated as a rapid and efficient method to genotype zebrafish.
1Experimental and Clinical Research Center (ECRC), Charité Medical Faculty and Max-Delbrück Center for Molecular Medicine (MDC), 2Medical Department, Division of Cardiology, Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin, 3Medical Department, Division of Cardiology and Angiology, Campus Mitte, Charité - Universitätsmedizin Berlin
Kv channel dysfunction is associated with cardiac arrhythmias. In order to study the molecular mechanisms that lead to such arrhythmias we utilize a systematic protocol for isolation of atrial and ventricular cardiomyocytes from Kv channel ancillary subunit knockout mice. Isolated cardiomyocytes can then immediately be used for cellular electrophysiological studies, biochemical or immunofluorescence (IF) assays.…
Published March 12, 2013. Keywords: Physiology, Medicine, Cellular Biology, Molecular Biology, Genetics, Biomedical Engineering, Anatomy, Cardiology, Cardiac Output, Low, Cardiomyopathies, Heart Failure, Arrhythmias, Cardiac, Ventricular Dysfunction, Cardiomyocytes, Kv channel, cardiac arrythmia, electrophysiology, patch clamp, mouse, animal model
1Laboratory of Molecular Biology of the Cell, Ecole Normale Supérieure de Lyon, 2INSERM U744, Institut Pasteur de Lille, Université Lille-Nord de France, 3Howard Hughes Medical Institute, Laboratory of Apoptosis and Cancer, The Rockefeller University
The Tomato/GFP-FLP/FRT method involves visualizing mosaic photoreceptor cells in living Drosophila. It can be used to follow individual photoreceptor cell fates in the retina for days or weeks. This method is ideal for studies of retinal degeneration and neurodegenerative diseases or photoreceptor cell development.
Published September 20, 2013. Keywords: Developmental Biology, Eye, Photoreceptor Cells, Genes, Developmental, neuron, visualization, degeneration, development, live imaging, Drosophila, photoreceptor, cornea neutralization, mitotic recombination
1Department of Cell Biology and Anatomy, College of Medicine, University of Arizona, Tucson, 2Southern Arizona Veterans Affairs Health Care System, Tucson, AZ, 3Department of Surgery, College of Medicine, University of Arizona, Tucson, 4Biomedical Diagnostics and Research, Tucson, AZ, 5Department of Medicine, College of Medicine, University of Arizona, Tucson
Reduced/absent expression of Pms2 and/or ERCC1 in entire crypts is a frequent event within 10 cm on each side of colonic adenocarcinomas, likely the basis of a field defect with high mutability and progression to cancer. Deficiency in Ku86 or CcOI is much less frequent in these field defects.
1Department of Obstetrics, Gynecology & Women's Health, Masonic Cancer Center, University of Minnesota, Minneapolis, 2Department of Genetics, Cell Biology & Development, Center for Genome Engineering, University of Minnesota, Minneapolis
A method of identifying unknown drivers of carcinogenesis using an unbiased approach is described. The method uses the Sleeping Beauty transposon as a random mutagen directed to specific tissues. Genomic mapping of transposon insertions that drive tumor formation identifies novel oncogenes and tumor suppressor genes
Published February 1, 2013. Keywords: Genetics, Medicine, Cancer Biology, Biomedical Engineering, Genomics, Mice, Genetic Techniques, life sciences, animal models, Neoplasms, Genetic Phenomena, Forward genetic screen, cancer drivers, mouse models, oncogenes, tumor suppressor genes, Sleeping Beauty transposons, insertions, DNA, PCR, animal model
Quantitative Fitness Analysis (QFA) is a complementary series of experimental and computational methods for estimating microbial culture fitnesses. QFA estimates the effect of genetic mutations, drugs or other applied treatments on microbe growth. Experiments scaling from focussed analysis of single cultures to thousands of parallel cultures can be designed.
1Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine, 2Department of Psychiatry, University of Iowa Carver College of Medicine, 3EZ BioResearch LLC
We describe procedures for labeling and genotyping newborn mice and generating primary neuronal cultures from them. The genotyping is rapid, efficient and reliable, and allows for automated nucleic-acid extraction. This is especially useful for neonatally lethal mice and their cultures that require prior completion of genotyping.
Ice-Cap: A Method for Growing Arabidopsis and Tomato Plants in 96-well Plates for High-Throughput Genotyping
The Ice-Cap method allows one to grow plants in 96-well plates and non-destructively harvest root tissue from each seedling. DNA extracted from this root tissue can be used for genotyping reactions. We have found that Ice-Cap works well for Arabidopsis thaliana, tomato, and rice seedlings.
Split-Ubiquitin Based Membrane Yeast Two-Hybrid (MYTH) System: A Powerful Tool For Identifying Protein-Protein Interactions
1Department of Biochemistry, University of Toronto, 2Department of Molecular Genetics, University of Toronto, 3Terrence Donnelly Centre for Cellular and Biomolecular Research (CCBR), University of Toronto
MYTH allows the sensitive detection of transient and stable interactions between proteins that are expressed in the model organism Saccharomyces cerevisiae. It has been successfully applied to study exogenous and yeast integral membrane proteins in order to identify their interacting partners in a high throughput manner.
Mutagenesis and Analysis of Genetic Mutations in the GC-rich KISS1 Receptor Sequence Identified in Humans with Reproductive Disorders
1Division of Endocrinology and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, 2Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine
Mutations in the kisspeptin receptor (KISS1R) are associated with reproductive disorders in patients. Here we describe how to introduce mutations of interest in the GC-rich sequence of KISS1R as well as the use of KISS1R constructs to characterize the degradation pathway of the receptor by immunoprecipitation and western blot.
1Institute of Laboratory Animal Science, University of Zurich, 2Department of Genetics, Cell Biology & Development and Center for Genome Engineering, University of Minnesota
Designer nucleases such as zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) can be used to modify the genome of mouse preimplantation embryos by triggering both the nonhomologous end joining (NHEJ) and homologous recombination (HR) pathways. These advances enable the rapid generation of mice with precise genetic modifications.
A Fluorescence-based Exonuclease Assay to Characterize DmWRNexo, Orthologue of Human Progeroid WRN Exonuclease, and Its Application to Other Nucleases
Exonucleases play critical roles in ensuring genome stability. Loss of WRN exonuclease function results in premature aging. Studying substrates and other requirements of the nuclease in vitro can help elucidate its role in vivo. Here we demonstrate a rapid and reproducible fluorescence-based assay to measure its nuclease activity.
1Department of Biomedicine, Immunoregulation, University of Basel and University Hospital Basel
Tail-skin transplantation is a powerful model for studying T cell-dependent rejection and tolerance induction during allogeneic immune responses in mice. The advantages of this protocol are minor invasive surgery, and ease of monitoring with no need to sacrifice the recipient mouse.
1Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine, University of Michigan Medical Center, 2Department of Molecular Pathology, University of Yamanashi
Recent development in gene targeting tools makes production of knockout (KO) rabbits possible. In the present work, we generated five Apolipoprotein (Apo) C-III KO rabbits using Zinc Finger Nucleases (ZFN). This work demonstrated that ZFN is a highly efficient method to produce KO rabbits.
Analysis of RNA Processing Reactions Using Cell Free Systems: 3' End Cleavage of Pre-mRNA Substrates in vitro
1Department of Infectious Diseases, The Scripps Research Institute, 2Department of Chemistry, City College of New York
RNA polymerase II synthesizes a precursor RNA that extends beyond the 3' end of the mature mRNA. The end of the mature RNA is generated cotranscriptionally, at a site dictated by RNA sequences, via the endonuclease activity of the cleavage complex. Here, we detail the method to study cleavage reactions in vitro.
1Department of Pediatrics, University of Alberta, 2Montreal Neurological Institute and Hospital, McGill University
We present an optimized inexpensive and reliable negative geotaxis assay in Drosophila melanogaster as a model for neurodegenerative disorders. Being more sensitive to mild locomotor defects, this assay will help screen for potential genetic interactions and drug targets.
When working with media and reagents used to culture microorganisms, aseptic technique must be practiced to ensure contamination is minimized. A variety of plating methods are routinely used to isolate, propagate, or enumerate bacteria and phage, all of which incorporate procedures that maintain the sterility of experimental materials.
Fluorescence-microscopy Screening and Next-generation Sequencing: Useful Tools for the Identification of Genes Involved in Organelle Integrity
A fundamental quest in cell biology is to define the mechanisms that underlie the identity of the organelles that make eukaryotic cells. Here we propose a method to identify the genes responsible for the morphological and functional integrity of plant organelles using fluorescence microscopy and next-generation sequencing tools.
1MRC/ARUK Centre for Musculoskeletal Ageing Research, University of Nottingham
Skeletal muscle is essential for locomotion and is the bodies’ main protein store. Muscle health measurements within C. elegans are described. Prospective changes to muscle structure and function are assessed using localized GFP and cationic dyes.