An "age" has passed in the 40 years since we first observed recovery from radiation damage in irradiated bacteria. During the early 1930s, we had been discussing the possibility of rapid changes after radiation exposure with Farring ton Daniels, Benjamin Duggar, John Curtis, and others at the University of Wisconsin. After working with living cells, we had concluded that organisms receiving massive insults must have a wide variety of repair mechanisms available for restoration of at least some of the essential properties of the cell. The problem was how to fmd and identify these recovery phenomena. At that time I was working on a problem considered to be of great importance-the existence of the so-called mitogenetic rays. Several hundred articles and a score of books had already appeared dealing with mitogenetic rays, a type of radiation that was thought to exist in the shorter ultraviolet region. Our search for mitogenetic rays necessitated the design of experiments of greatest sensitivity for the detection of ultraviolet. It was vital that conditions be kept as constant as possible during exposure. All the work was done at icewater temperature (3-5°C) during and after exposure. We knew that light was an important factor for cell recovery, so all our experiments were done in dim light, with the plated-out cells being covered with dark cloth. Our statements on the effect of visible light stimulated Kelner to search for "photoreactivation' (as it was later called).

This book is a comprehensive review of the detailed molecular mechanisms of and functional crosstalk among the replication, recombination, and repair of DNA (collectively called the "3Rs") and the related processes, with special consciousness of their biological and clinical consequences. The 3Rs are fundamental molecular mechanisms for organisms to maintain and sometimes intentionally alter genetic information. DNA replication, recombination, and repair, individually, have been important subjects of molecular biology since its emergence, but we have recently become aware that the 3Rs are actually much more intimately related to one another than we used to realize. Furthermore, the 3R research fields have been growing even more interdisciplinary, with better understanding of molecular mechanisms underlying other important processes, such as chromosome structures and functions, cell cycle and checkpoints, transcriptional and epigenetic regulation, and so on. This book comprises 7 parts and 21 chapters: Part 1 (Chapters 1–3), DNA Replication; Part 2 (Chapters 4–6), DNA Recombination; Part 3 (Chapters 7–9), DNA Repair; Part 4 (Chapters 10–13), Genome Instability and Mutagenesis; Part 5 (Chapters 14–15), Chromosome Dynamics and Functions; Part 6 (Chapters 16–18), Cell Cycle and Checkpoints; Part 7 (Chapters 19–21), Interplay with Transcription and Epigenetic Regulation. This volume should attract the great interest of graduate students, postdoctoral fellows, and senior scientists in broad research fields of basic molecular biology, not only the core 3Rs, but also the various related fields (chromosome, cell cycle, transcription, epigenetics, and similar areas). Additionally, researchers in neurological sciences, developmental biology, immunology, evolutionary biology, and many other fields will find this book valuable.

DNA Repair Mechanisms is an account of the proceedings at a major international conference on DNA Repair Mechanisms held at Keystone, Colorado on February 1978. The conference discusses through plenary sessions the overall standpoint of DNA repair. The papers presented and other important documents, such as short summaries by the workshop session conveners, comprise this book. The compilation describes the opposing views, those that agree and dispute about certain topic areas. This book, divided into 15 parts, is arranged according to the proceedings in the conference. The plenary sessions are ...

An essential resource for all scientists researching cellular responses to DNA damage. • Introduces important new material reflective of the major changes and developments that have occurred in the field over the last decade. • Discussed the field within a strong historical framework, and all aspects of biological responses to DNA damage are detailed. • Provides information on covering sources and consequences of DNA damage; correcting altered bases in DNA: DNA repair; DNA damage tolerance and mutagenesis; regulatory responses to DNA damage in eukaryotes; and disease states associated with defective biological responses to DNA damage.

To understand the molecular mechanisms of XP, XP mouse models have been used, and mice deficient in XPA, XPC, XPD, XPG, XPF, and XPA/CSB have been produced and analysed. A recent elegant technique of targeting gene replacement in mouse embryonic stem cells has provided researchers with the ability to generate mutant mice defective in any specific gene(s). 32 Animals generated in this way display phenotypes and symptoms of XP patients, and have provided valuable tools to understand how and where the deficiency in DNA repair may lead to tumor formation, and also in studies of developmental biology and the aging process. Mouse studies have recently contributed to our understanding of the role of ink4a-Arf in increasing the risk of melanoma photocarcinogenesis in an XPC mutant background. As with many other genetic defects, the distribution of XP globally is not uniform. In most cases the frequency of mutation of a particular trait depends when and where a specific mutation arose, and the longer ago that is, the greater the frequency of mutant in the population unless some selective pressure prevailed. Another factor responsible for the high incidence of any mutation is consanguinity. One of the last chapters analyzes the world distribution of XP and shows that Japan has the highest incidence of XP and of varying complementation groups. After Japan perhaps Egypt suffers most from this inborn error. Here it is also shown that the most common complementation groups are XPA and XPC followed by XPV. XPB and XPE are least frequent. In a recent publication, however, 16 Japanese patients with XPV have been diagnosed and confirmed both clinically and at the cellular level. There is no evidence that interest in XP is waning, and this book should provide both the expert and novice researcher in the field with an excellent overview of the current status of research and pointers to future research goals.

Stands as the most comprehensive guide to the subject-covering every essential topic related to DNA damage identification and repair. Covering a wide array of topics from bacteria to human cells, this book summarizes recent developments in DNA damage repair and recognition while providing timely reviews on the molecular mechanisms employe