RNA interference (RNAi) is a widely used technique in which double stranded RNA is exogenously introduced into an organism, causing knockdown of a target gene. In the nematode, C. elegans, RNAi is particularly easy and effective because it can be delivered simply by feeding the worms bacteria that express double stranded RNA (dsRNA) that is complementary to a gene of interest. First,…
DNA replication has three main steps: initiation, elongation, and termination. Replication in prokaryotes begins when initiator proteins bind to the single origin of replication (ori) on the cell’s circular chromosome. Replication then proceeds around the entire circle of the chromosome in each direction from two replication forks, resulting in two DNA molecules.
Replication is coordinated and carried out by a host of specialized proteins. Topoisomerase breaks one side of the double-stranded DNA phosphate-sugar backbone, allowing the DNA helix to unwind more rapidly, while helicase breaks the bonds between base pairs at the fork, separating the DNA into two template strands. Proteins that bind single-stranded DNA molecules stabilize the strands as the replication fork travels along the chromosome. DNA can only be synthesized in the 5’ to 3’ direction, so one strand of the template—the leading strand—is elongated continuously, while the other strand—the lagging strand—is synthesized in shorter pieces of 1000-2000 base pairs called Okazaki fragments. Much of the research to understand prokaryotic DNA replication has been performed in the bacterium Escherichia coli, a commonly-used model organism. E. coli has 5 DNA polymerases: Pol I, II, III, IV, and V. Pol III is responsible for the majority of DN…
1Department of Microbial Pathogenesis, Yale University School of Medicine, 2Program in Vertebrate Developmental Biology, Departments of Pediatrics and Genetics, Yale University School of Medicine, 3Department of Internal Medicine, Yale University School of Medicine
Detection of the Genome and Transcripts of a Persistent DNA Virus in Neuronal Tissues by Fluorescent In situ Hybridization Combined with Immunostaining
1Virus and Centromere Team, Centre de Génétique et Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, 2Université de Lyon 1, 3Laboratoire d'excellence, LabEX DEVweCAN, 4Institut de Virologie Moléculaire et Structurale, CNRS UPR 3296, 5Centre de Recherche en Cancérologie de Lyon, INSERM U1052, CNRS UMR 5286
Immunoglobulin Gene Sequence Analysis In Chronic Lymphocytic Leukemia: From Patient Material To Sequence Interpretation
1Institute of Applied Biosciences, Centre for Research and Technology Hellas, 2Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, 3Department of Molecular Medicine and Surgery, Karolinska Institutet, 4Division of Immunology, Transplantation and Infectious, IRCCS San Raffaele Scientific Institute, 5Department of Immunology, Laboratory for Medical Immunology, Erasmus University Medical Center, 6Hematology Department, Nikea General Hospital, 7Assistance publique - Hôpitaux de Paris (AP-HP), Hopital Pitié-Salpêtrière, Department of Hematology, and UPMC University Paris 06, UMRS 1138, 8Division of Experimental Oncology, IRCCS Istituto Scientifico San Raffaele and Università Vita-Salute San Raffaele