The Evolving Telomeres

The Evolving Telomeres
Author: Arthur J. Lustig
Publisher: Frontiers Media SA
Total Pages: 76
Release: 2016-07-19
Genre: Genetics
ISBN: 2889198812

What controls the different rates of evolution to give rise to conserved and divergent proteins and RNAs? How many trials until evolution can adapt to physiological changes? Every organism has arisen through multiple molecular changes, and the mechanisms that are employed (mutagenesis, recombination, transposition) have been an issue left to the elegant discipline of evolutionary biology. But behind the theory are realities that we have yet to ascertain: How does an evolving cell accommodate its requirements for both conserving its essential functions, while also providing a selective advantage? In this volume, we focus on the evolution of the eukaryotic telomere, the ribo-nuclear protein complex at the end of a linear chromosome. The telomere is an example of a single chromosomal element that must function to maintain genomic stability. The telomeres of all species must provide a means to avoid the attrition from semi-conservative DNA replication and a means of telomere elongation (the telomere replication problem). For example, telomerase is the most well-studied mechanism to circumvent telomere attrition by adding the short repeats that constitutes most telomeres. The telomere must also guard against the multiple activities that can act on an unprotected double strand break requiring a window (or checkpoint) to compensate for telomere sequence loss as well as protection against non-specific processes (the telomere protection problem). This volume describes a range of methodologies including mechanistic studies, phylogenetic comparisons and data-based theoretical approaches to study telomere evolution over a broad spectrum of organisms that includes plants, animals and fungi. In telomeres that are elongated by telomerases, different components have widely different rates of evolution. Telomerases evolved from roots in archaebacteria including splicing factors and LTR-transposition. At the conserved level, the telomere is a rebel among double strand breaks (DSBs) and has altered the function of the highly conserved proteins of the ATM pathway into an elegant means of protecting the chromosome end and maintaining telomere size homeostasis through a competition of positive and negative factors. This homeostasis, coupled with highly conserved capping proteins, is sufficient for protection. However, far more proteins are present at the telomere to provide additional species-specific functions. Do these proteins provide insight into how the cell allows for rapid change without self-destruction?

Origin and Evolution of Telomeres

Origin and Evolution of Telomeres
Author: Jozef Nosek
Publisher: CRC Press
Total Pages: 194
Release: 2008-05-26
Genre: Science
ISBN: 9781587063091

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.

Telomeres and Telomerase in Cancer

Telomeres and Telomerase in Cancer
Author: Keiko Hiyama
Publisher: Springer Science & Business Media
Total Pages: 375
Release: 2009-03-18
Genre: Medical
ISBN: 1603278796

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.

Evolution and Impact of Transposable Elements

Evolution and Impact of Transposable Elements
Author: Pierre Capy
Publisher: Springer Science & Business Media
Total Pages: 366
Release: 1998-01-31
Genre: Science
ISBN: 9780792346906

During the last 50 years, the perception oftransposable elements (TEs) has changed considerably from selfish DNA to sequences that may contribute significantly to genome function and evolution. The recent increased interest in TEs is based on the realization that they are a major genetic component (at least 10--20%) of all organisms and a major contributor to the mutation process. It is currently estimated that 70--80% of spontaneous mutations are the result of TE-mediated insertions, deletions, or chromosomal rearrangements. Thus, it seems at least plausible that TEs may playa significant role in the adaptation and evolution of natural populations and species. The ubiquity of TEs suggests that they are an old component of genomes which have been vertically transmitted through generations over evolutionary time. However, detailed analyses carried out over the last 20 years have revealed several unusual features of TE evolution: (i) TEs can be horizontally transferred between species; (ii) TE evolutionary rates can be dramatically increased by specific inactivation processes, such as the RIP (Repeat Induced Point mutation) mechanism in fungi; (iii) TEs can influence the regulation of other TEs by insertion or deletion; (iv) different classes of TEs in even distantly related species can be remarkably similar in both structure and function.

The Telomere Effect

The Telomere Effect
Author: Dr. Elizabeth Blackburn
Publisher: Grand Central Publishing
Total Pages: 307
Release: 2017-01-03
Genre: Health & Fitness
ISBN: 1455587966

The New York Times bestselling book coauthored by the Nobel Prize winner who discovered telomerase and telomeres' role in the aging process and the health psychologist who has done original research into how specific lifestyle and psychological habits can protect telomeres, slowing disease and improving life. Have you wondered why some sixty-year-olds look and feel like forty-year-olds and why some forty-year-olds look and feel like sixty-year-olds? While many factors contribute to aging and illness, Dr. Elizabeth Blackburn discovered a biological indicator called telomerase, the enzyme that replenishes telomeres, which protect our genetic heritage. Dr. Blackburn and Dr. Elissa Epel's research shows that the length and health of one's telomeres are a biological underpinning of the long-hypothesized mind-body connection. They and other scientists have found that changes we can make to our daily habits can protect our telomeres and increase our health spans (the number of years we remain healthy, active, and disease-free). The Telemere Effect reveals how Blackburn and Epel's findings, together with research from colleagues around the world, cumulatively show that sleep quality, exercise, aspects of diet, and even certain chemicals profoundly affect our telomeres, and that chronic stress, negative thoughts, strained relationships, and even the wrong neighborhoods can eat away at them. Drawing from this scientific body of knowledge, they share lists of foods and suggest amounts and types of exercise that are healthy for our telomeres, mind tricks you can use to protect yourself from stress, and information about how to protect your children against developing shorter telomeres, from pregnancy through adolescence. And they describe how we can improve our health spans at the community level, with neighborhoods characterized by trust, green spaces, and safe streets. The Telemere Effect will make you reassess how you live your life on a day-to-day basis. It is the first book to explain how we age at a cellular level and how we can make simple changes to keep our chromosomes and cells healthy, allowing us to stay disease-free longer and live more vital and meaningful lives.

Telomeres

Telomeres
Author: Titia De Lange
Publisher:
Total Pages: 598
Release: 2006
Genre: Medical
ISBN:

An up-to-date survey of the current exciting state of telomere biology. Telomeres – specialized structures found at the ends of chromosomes – are essential for maintaining the integrity of chromosomes and their faithful duplication during cell division. Chapters in this volume cover telomere structure and function in a range of organisms, focusing on how they are maintained, their roles in cell division and gene expression, and how deficiencies in these structures contribute to cancers and other diseases and even aging.

Elizabeth Blackburn and the Story of Telomeres

Elizabeth Blackburn and the Story of Telomeres
Author: Catherine Brady
Publisher: MIT Press
Total Pages: 405
Release: 2009-02-13
Genre: Biography & Autobiography
ISBN: 0262261960

The story of molecular biologist Elizabeth Blackburn and her groundbreaking research on telomeres and what it reveals about the resourceful opportunism that characterizes the best scientific thinking. Molecular biologist Elizabeth Blackburn—one of Time magazine's 100 “Most Influential People in the World” in 2007—made headlines in 2004 when she was dismissed from the President's Council on Bioethics after objecting to the council's call for a moratorium on stem cell research and protesting the suppression of relevant scientific evidence in its final report. But it is Blackburn's groundbreaking work on telomeric DNA, which launched the field of telomere research, that will have the more profound and long-lasting effect on science and society. In this compelling biography, Catherine Brady tells the story of Elizabeth Blackburn's life and work and the emergence of a new field of scientific research on the specialized ends of chromosomes and the enzyme, telomerase, that extends them. In the early stages of telomere research, telomerase, heralded as a potential cure for cancer and diseases related to aging, attracted the voracious interest of biotech companies. The surrounding hype succeeded in confusing the role of telemorase in extending the life of a cell with a mechanism that might extend the lifespan of an entire organism. In Brady's hands, Blackburn's story reveals much about the tension between pure and applied science, the politicking that makes research science such a competitive field, and the resourceful opportunism that characterizes the best scientific thinking. Brady describes the science accessibly and compellingly. She explores Blackburn's struggle to break down barriers in an elite, male-dominated profession, her role as a mentor to other women scientists (many of whom have made their mark in telomere research), and the collaborative nature of scientific work. This book gives us a vivid portrait of an exceptional woman and a new understanding of the combination of curiosity, imaginative speculation, and aesthetic delight that powers scientific discovery.

Relics of Eden

Relics of Eden
Author: Daniel J. Fairbanks
Publisher: Prometheus Books
Total Pages: 294
Release: 2009-09-18
Genre: Science
ISBN: 1615920099

Since the publication in 1859 of Darwin’s Origin of Species, debate over the theory of evolution has been continuous and often impassioned. In recent years, opponents of "Darwin’s dangerous idea" have mounted history’s most sophisticated and generously funded attack, claiming that evolution is "a theory in crisis." Ironically, these claims are being made at a time when the explosion of information from genome projects has revealed the most compelling and overwhelming evidence of evolution ever discovered. Much of the latest evidence of human evolution comes not from our genes, but from so-called "junk DNA," leftover relics of our evolutionary history that make up the vast majority of our DNA. Relics of Eden explores this powerful DNA-based evidence of human evolution. The "relics" are the millions of functionally useless but scientifically informative remnants of our evolutionary ancestry trapped in the DNA of every person on the planet. For example, the analysis of the chimpanzee and Rhesus monkey genomes shows indisputable evidence of the human evolutionary relationship with other primates. Over 95 percent of our genome is identical with that of chimpanzees and we also have a good deal in common with other animal species. Author Daniel J. Fairbanks also discusses what DNA analysis reveals about where humans originated. The diversity of DNA sequences repeatedly confirms the archeological evidence that humans originated in sub-Saharan Africa (the "Eden" of the title) and from there migrated through the Middle East and Asia to Europe, Australia, and the Americas. In conclusion, Fairbanks confronts the supposed dichotomy between evolution and religion, arguing that both science and religion are complementary ways to seek truth. He appeals to the vast majority of Americans who hold religious convictions not to be fooled by the pseudoscience of Creationists and Intelligent Design advocates and to abandon the false dichotomy between religion and real science. This concise, very readable presentation of recent genetic research is completely accessible to the nonspecialist and makes for enlightening and fascinating reading.

The Evolution of Senescence in the Tree of Life

The Evolution of Senescence in the Tree of Life
Author: Richard P. Shefferson
Publisher: Cambridge University Press
Total Pages: 445
Release: 2017-02-23
Genre: Science
ISBN: 1108138608

The existing theories on the evolution of senescence assume that senescence is inevitable in all organisms. However, recent studies have shown that this is not necessarily true. A better understanding of senescence and its underlying mechanisms could have far-reaching consequences for conservation and eco-evolutionary research. This book is the first to offer interdisciplinary perspectives on the evolution of senescence in many species, setting the stage for further developments. It brings together new insights from a wide range of scientific fields and cutting-edge research done on a multitude of different animals (including humans), plants and microbes, giving the reader a complete overview of recent developments and of the controversies currently surrounding the topic. Written by specialists from a variety of disciplines, this book is a valuable source of information for students and researchers interested in ageing and life history traits and populations.

Quantitative Genetics in the Wild

Quantitative Genetics in the Wild
Author: Anne Charmantier
Publisher: Oxford University Press
Total Pages: 293
Release: 2014
Genre: Medical
ISBN: 019967423X

This book gathers the expertise of 30 evolutionary biologists from around the globe to highlight how applying the field of quantitative genetics - the analysis of the genetic basis of complex traits - aids in the study of wild populations.