At least 5 trillion cell divisions are required for a fertilized egg to develop into an adult human, resulting in the production of more than 20 trillion meters of DNA! And yet, with only two exceptions, the genome is replicated once and only once each time a cell divides. How is this feat accomplished? What happens when errors occur? This book addresses these questions by presenting a thorough analysis of the molecular events that govern DNA replication in eukaryotic cells. The association between genome replication and cell proliferation, disease pathogenesis, and the development of targeted therapeutics is also addressed. At least 160 proteins are involved in replicating the human genome, and at least 40 diseases are caused by aberrant DNA replication, 35 by mutations in genes required for DNA replication or repair, 7 by mutations generated during mitochondrial DNA replication, and more than 40 by DNA viruses. Consequently, a growing number of therapeutic drugs are targeted to DNA replication proteins. This authoritative volume provides a rich source of information for researchers, physicians, and teachers, and will stimulate thinking about the relevance of DNA replication to human disease.
DNA Repair and Replication brings together contributions from active researchers. The first part of this book covers most aspects of the DNA damage response, emphasizing the relationship to replication stress. The second part concentrates on the relevance of this to human disease, with particular focus on both the causes and treatments which make use of DNA Damage Repair (DDR) pathways. Key Selling Features: Chapters written by leading researchers Includes description of replication processes, causes of damage, and methods of repair
This book reviews the latest trends and future directions of DNA replication research. The contents reflect upon the principles that have been established through the genetic and enzymatic studies of bacterial, viral, and cellular replication during the past decades. The book begins with a historical overview of the studies on eukaryotic DNA replication by Professor Thomas Kelly, a pioneer of the field. The following chapters include genome-wide studies of replication origins and initiation factor binding, as well as the timing of DNA replications, mechanisms of initiation, DNA chain elongation and termination of DNA replication, the structural basis of functions of protein complexes responsible for execution of DNA replication, cell cycle-dependent regulation of DNA replication, the nature of replication stress and cells’ strategy to deal with the stress, and finally how all these phenomena are interconnected to genome instability and development of various diseases. By reviewing the existing concepts ranging from the old principles to the newest ideas, the book gives readers an opportunity to learn how the classical replication principles are now being modified and new concepts are being generated to explain how genome DNA replication is achieved with such high adaptability and plasticity. With the development of new methods including cryoelectron microscopy analyses of huge protein complexes, single molecular analyses of initiation and elongation of DNA replication, and total reconstitution of eukaryotic DNA replication with purified factors, the field is enjoying one of its most exciting moments, and this highly timely book conveys that excitement to all interested readers.
Environmental stresses and metabolic by-products can severely affect the integrity of genetic information by inducing DNA damage and impairing genome stability. As a consequence, plant growth and productivity are irreversibly compromised. To overcome genotoxic injury, plants have evolved complex strategies relying on a highly efficient repair machinery that responds to sophisticated damage perception/signaling networks. The DNA damage signaling network contains several key components: DNA damage sensors, signal transducers, mediators, and effectors. Most of these components are common to other eukaryotes but some features are unique to the plant kingdom. ATM and ATR are well-conserved members of PIKK family, which amplify and transduce signals to downstream effectors. ATM primarily responds to DNA double strand breaks while ATR responds to various forms of DNA damage. The signals from the activated transducer kinases are transmitted to the downstream cell-cycle regulators, such as CHK1, CHK2, and p53 in many eukaryotes. However, plants have no homologue of CHK1, CHK2 nor p53. The finding of Arabidopsis transcription factor SOG1 that seems functionally but not structurally similar to p53 suggests that plants have developed unique cell cycle regulation mechanism. The double strand break repair, recombination repair, postreplication repair, and lesion bypass, have been investigated in several plants. The DNA double strand break, a most critical damage for organisms are repaired non-homologous end joining (NHEJ) or homologous recombination (HR) pathway. Damage on template DNA makes replication stall, which is processed by translesion synthesis (TLS) or error-free postreplication repair (PPR) pathway. Deletion of the error-prone TLS polymerase reduces mutation frequencies, suggesting PPR maintains the stalled replication fork when TLS is not available. Unveiling the regulation networks among these multiple pathways would be the next challenge to be completed. Some intriguing issues have been disclosed such as the cross-talk between DNA repair, senescence and pathogen response and the involvement of non-coding RNAs in global genome stability. Several studies have highlighted the essential contribution of chromatin remodeling in DNA repair DNA damage sensing, signaling and repair have been investigated in relation to environmental stresses, seed quality issues, mutation breeding in both model and crop plants and all these studies strengthen the idea that components of the plant response to genotoxic stress might represent tools to improve stress tolerance and field performance. This focus issue gives researchers the opportunity to gather and interact by providing Mini-Reviews, Commentaries, Opinions, Original Research and Method articles which describe the most recent advances and future perspectives in the field of DNA damage sensing, signaling and repair in plants. A comprehensive overview of the current progresses dealing with the genotoxic stress response in plants will be provided looking at cellular and molecular level with multidisciplinary approaches. This will hopefully bring together valuable information for both plant biotechnologists and breeders.
Repetitive DNA is ubiquitous in eukaryotic genomes, and, in many species, comprises the bulk of the genome. Repeats include transposable elements that can self-mobilize and disperse around the genome, and tandemly-repeated satellite DNAs that increase in copy number due to replication slippage and unequal crossing over. Despite their abundance, repetitive DNA is often ignored in genomic studies due to technical challenges in their identification, assembly, and quantification. New technologies and methods are now providing the unprecedented power to analyze repetitive DNAs across diverse taxa. Repetitive DNA is of particular interest because it can represent distinct modes of genome evolution. Some repetitive DNA forms essential genome structures, such as telomeres and centromeres, which are required for proper chromosome maintenance and segregation, whereas others form piRNA clusters that regulate transposable elements; thus, these elements are expected to evolve under purifying selection. In contrast, other repeats evolve selfishly and produce genetic conflicts with their host species that drive adaptive evolution of host defense systems. However, the majority of repeats likely accumulate in eukaryotes in the absence of selection due to mechanisms of transposition and unequal crossing over. Even these neutral repeats may indirectly influence genome evolution as they reach high abundance. In this Special Issue, the contributing authors explore these questions from a range of perspectives.
"Microbiology covers the scope and sequence requirements for a single-semester microbiology course for non-majors. The book presents the core concepts of microbiology with a focus on applications for careers in allied health. The pedagogical features of the text make the material interesting and accessible while maintaining the career-application focus and scientific rigor inherent in the subject matter. Microbiology's art program enhances students' understanding of concepts through clear and effective illustrations, diagrams, and photographs. Microbiology is produced through a collaborative publishing agreement between OpenStax and the American Society for Microbiology Press. The book aligns with the curriculum guidelines of the American Society for Microbiology."--BC Campus website.
This Special Issue of International Journal of Molecular Sciences (IJMS) is dedicated to the mechanisms mediated at the molecular and cellular levels in response to adverse genomic perturbations and DNA replication stress. The relevant proteins and processes play paramount roles in nucleic acid transactions to maintain genomic stability and cellular homeostasis. A total of 18 articles are presented which encompass a broad range of highly relevant topics in genome biology. These include replication fork dynamics, DNA repair processes, DNA damage signaling and cell cycle control, cancer biology, epigenetics, cellular senescence, neurodegeneration, and aging. As Guest Editor for this IJMS
Innovations in molecular biology are allowing neuroscientists to study the brain with unprecedented resolution, from the level of single molecules to integrated gene circuits. Chief among these innovations is the CRISPR-Cas genome editing technology, which has the precision and scalability to tackle the complexity of the brain. This Colloque Médecine et Recherche has brought together experts from around the world that are applying genome editing to address important challenges in neuroscience, including basic biology in model organisms that has the power to reveal systems-level insight into how the nervous system develops and functions as well as research focused on understanding and treating human neurological disorders. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.
