Telomeres are essential functional elements of eukaryotic chromosomes. Their fundamental biological role as protectors of chromosome stability was identified for the first time in the 1930s by Hermann Muller and Barbara McClintock based on pioneering cytological experiments. Modern molecular research carried out more recently revealed that telomeres and telomerase play important roles in processes such as carcinogenesis and cellular senescence. This special issue presents the most recent developments in this highly active field of research. It is becoming increasingly clear that molecular pathways involved in regulation of telomere length and structure are functionally linked with pathways involved in DNA damage response, cellular stress response, chromatin organization and perhaps even pathways that regulate evolutionary chromosome rearrangements. The above functional link is explored by the leading experts in the field of telomere biology. Cell biologists, molecular biologists, oncologists, gerontologists, and radiobiologists with an interest in the role of telomeres/telomerase will appreciate the up-to-date information in this publication.

Genome Stability: From Virus to Human Application, Second Edition, a volume in the Translational Epigenetics series, explores how various species maintain genome stability and genome diversification in response to environmental factors. Here, across thirty-eight chapters, leading researchers provide a deep analysis of genome stability in DNA/RNA viruses, prokaryotes, single cell eukaryotes, lower multicellular eukaryotes, and mammals, examining how epigenetic factors contribute to genome stability and how these species pass memories of encounters to progeny. Topics also include major DNA repair mechanisms, the role of chromatin in genome stability, human diseases associated with genome instability, and genome stability in response to aging. This second edition has been fully revised to address evolving research trends, including CRISPRs/Cas9 genome editing; conventional versus transgenic genome instability; breeding and genetic diseases associated with abnormal DNA repair; RNA and extrachromosomal DNA; cloning, stem cells, and embryo development; programmed genome instability; and conserved and divergent features of repair. This volume is an essential resource for geneticists, epigeneticists, and molecular biologists who are looking to gain a deeper understanding of this rapidly expanding field, and can also be of great use to advanced students who are looking to gain additional expertise in genome stability. - A deep analysis of genome stability research from various kingdoms, including epigenetics and transgenerational effects - Provides comprehensive coverage of mechanisms utilized by different organisms to maintain genomic stability - Contains applications of genome instability research and outcomes for human disease - Features all-new chapters on evolving areas of genome stability research, including CRISPRs/Cas9 genome editing, RNA and extrachromosomal DNA, programmed genome instability, and conserved and divergent features of repair

The ?eld of cellular responses to DNA damage has attained widespread recognition and interest in recent years commensurate with its fundamental role in the ma- tenance of genomic stability. These responses, which are essential to preventing cellular death or malignant transformation, are organized into a sophisticated s- tem designated the “DNA damage response”. This system operates in all living organisms to maintain genomic stability in the face of constant attacks on the DNA from a variety of endogenous by-products of normal metabolism, as well as exogenous agents such as radiation and toxic chemicals in the environment. The response repairs DNA damage via an intricate cellular signal transduction network that coordinates with various processes such as regulation of DNA replication, tr- scriptional responses, and temporary cell cycle arrest to allow the repair to take place. Defects in this system result in severe genetic disorders involving tissue degeneration, sensitivity to speci?c damaging agents, immunode?ciency, genomic instability, cancer predisposition and premature aging. The ?nding that many of the crucial players involved in DNA damage response are structurally and functionally conserved in different species spurred discoveries of new players through similar analyses in yeast and mammals. We now understand the chain of events that leads to instantaneous activation of the massive cellular responses to DNA lesions. This book summarizes several new concepts in this rapidly evolving ?eld, and the advances in our understanding of the complex network of processes that respond to DNA damage.

Within the past two decades, extraordinary new functions for the nucleolus have begun to appear, giving the field a new vitality and generating renewed excitement and interest. These new discoveries include both newly-discovered functions and aspects of its conventional role. The Nucleolus is divided into three parts: nucleolar structure and organization, the role of the nucleolus in ribosome biogenesis, and novel functions of the nucleolus.

Linear chromosomes represent an evolutionary innovation associated with the origin of eukaryotic cells. This book describes how linear chromosomes and primordial pathways for maintaining their terminal structures, telomeres, emerged in early eukaryotes. Telomeres, derived from the Greek meaning terminal part, were first described by Hermann Muller in 1938. Telomeres are specialized structures that comprise the ends of linear chromosomes in eukaryotes. Linearity is crucial for chromosome pairing during meiosis and sexual reproduction. Inspired by Dobzhansky's dictum that "nothing in biology makes sense except in the light of evolution", this book brings together information about the origin and evolution of telomeres, their functions and the consequences of eukaryotic linearity which is an essential prerequisite of meiotic cell division and sexual reproduction. Selective pressure toward linearization must have been associated with the emergence of robust and redundant mechanisms for the maintenance of telomeres. These pathways comprise a molecular clock involved in cell senescence, carcinogenesis and immortalization.

Telomerase, an enzyme that maintains telomeres and endows eukaryotic cells with immortality, was first discovered in tetrahymena in 1985. In 1990s, it was proven that this enzyme also plays a key role in the infinite proliferation of human cancer cells. Now telomere and telomerase are widely accepted as important factors involved in cancer biology, and as promising diagnostic tools and therapeutic targets. Recently, role of telomerase in “cancer stem cells” has become another attractive story. Until now, there are several good books on telomere and telomerase focusing on biology in ciliates, yeasts, and mouse or basic sciences in human, providing basic scientists or students with updated knowledge.