This book examines the genetic circuitry of the well-known "fruit fly," tackling questions of cell assemblage and pattern formation, of the hows and the whys behind the development of the fly. After an initial examination of the proximity versus pedigree imperatives, the volume delves into bristle pattern formation and disc development, with entire chapters devoted to the leg, wing, and eye. Extensive appendices include a glossary of protein domains, catalogs of well-studied genes, and an outline of signaling pathways. More than 30 wiring diagrams among over 60 detailed schematics clarify the text.

Biology of Aging, Second Edition presents the biological principles that have led to a new understanding of the causes of aging and describes how these basic principles help one to understand the human experience of biological aging, longevity, and age-related disease. Intended for undergraduate biology students, it describes how the rate of biological aging is measured; explores the mechanisms underlying cellular aging; discusses the genetic pathways that affect longevity in various organisms; outlines the normal age-related changes and the functional decline that occurs in physiological systems over the lifespan; and considers the implications of modulating the rate of aging and longevity. The book also includes end-of-chapter discussion questions to help students assess their knowledge of the material. Roger McDonald received his Ph.D. from the University of Southern California and is Professor Emeritus in the Department of Nutrition at the University of California, Davis. Dr. McDonald's research focused on mechanisms of cellular aging and the interaction between nutrition and aging. His research addressed two key topics in the field: the relationship between dietary restriction and lifespan, and the effect of aging on circadian rhythms and hypothalamic regulation. You can contact Dr. McDonald at [email protected]. Related Titles Ahmad, S. I., ed. Aging: Exploring a Complex Phenomenon (ISBN 978-1-1381-9697-1) Moody, H. R. & J. Sasser. Gerontology: The Basics (ISBN 978-1-1387-7582-4) Timiras, P. S. Physiological Basis of Aging and Geriatrics (ISBN 978-0-8493-7305-3)

This is the first book about both normal development of the nervous system and how early exposure to alcohol and nicotine interferes with this development. The developing nervous system is highly dynamic and vulnerable to genetic and epigenetic factors that can be additive or synergistic. Disruption of normal brain development leads to an array of developmental disorders. One of the most common of these is mental retardation, the prime cause of which is prenatal exposure to alcohol. As chapters in this book show, alcohol has direct effects on the developing neural system and it affects genetic regulation. Another common neurotoxin is nicotine, and it is discussed in this book for three reasons: (1) the number of adolescents who smoke cigarettes is rising in some populations; (2) prenatal exposure to nicotine affects neurotransmitter systems that are critical for normal brain development and cognition; and (3) prenatal exposure to nicotine is often accompanied by prenatal exposure to alcohol.LThe mature brain is the culmination of an orderly sequence of the basic ontogenetic processes--cell proliferation, migration, differentiation, and death. Neural stem cells and progenitors proliferate in discrete sites; then, young neurons migrate long distances to their residences where they form neural networks. During this sequence many immature cells die, presumably eliminating unsuitable or non-competitive cells. Each process is regulated by genetic and environmental factors. When this regulation goes awry, a dysmorphic and dysfunctional brain results. Though this can be tragic in clinical settings, in experimental contexts it provides keen insight into normal brain development.LThe book isdivided into three parts. The first describes neural ontogeny in the normal brain. The second and third deal with the consequences of early exposure to alcohol and nicotine. Though there are similarities in the effects of these two toxins, there are also intriguing differences. The commonalities reflect the plasticity and resilience of the developing brain while the differences point to the targeted effects of the two toxins. Exploring these effects brings a richer appreciation of brain development. The book will be of interest to neuroscientists, developmental biologists, teratologists, pharmacologists, toxicologists, neurologists, neuropsychologists, and to their students and trainees.

Unwanted childlessness affects approximately one in six couples worldwide. - though the exact proportion of the predominant cause of the problem remains controversial, according to the World Health Organization (WHO), in nearly 40% of cases the cause can be attributed to the female, in 20% to the male, in 25% to both, and in 15% the cause remains unknown. Based on these ?gures, the - cidence of male factor infertility in the general population is approximately 7%. The majority of these men, approximately 30%, experience irreversible idiopathic infertility and cannot father children without some form of medical intervention. Male factor infertility, in addition, may be caused by testicular germ cell cancer, which is known to represent the most common cancer among young men, aged 15 to 35 years, in Western industrialized countries. The number of affected men has increased dramatically over the past 50 years. There is now growing evidence that human testicular germ cell cancer originates from fetal germ cells exhibiting an aberrant programme of gene expression, and tumour progression may be favoured by an aberrant Sertoli cell-germ cell communication.

Fungal Morphogenesis brings together in one book, for the first time, the full scope of fungal developmental biology. The book provides a coherent account of the subject and puts forward ideas that can provide a basis for future research. Throughout, the author blends together physiological, biochemical, structural and molecular descriptions within an evolutionary framework. Sufficient information is provided about fungal biology to give the reader a rounded view of the mycological context within which fungal morphogenesis is played out, without obscuring the broader biological significance. The author is careful to avoid jargon and demystifies technical terms. Written by one of the few people with the necessary breadth of research expertise to deal authoritatively with the wide range of topics presented, this book will appeal to developmental and cell biologists, microbiologists, and geneticists.

Scientists investigating germ cells have, over the past 15 years, originated discoveries and innovations that give us valuable insights into the mechanisms that regulate not just stem cell function, but human development in its widest sense. With contributions from some of the leading researchers in the field, Male Germline Stem Cells: Developmental and Regenerative Potential assesses the implications of these discoveries for understanding the fundamental biology of germline stem cells as well as their potential for human stem cell-based therapies. This monograph covers many of the fundamental issues now being explored by today's generation of stem cell researchers, including the field's potential for regenerative medicine. Ranging from an assessment of the pluripotency of primordial germ cells and their possible applications in treating testicular cancer, to the recovery of once-mordant fertilization-competent sperm, this volume has it all. It is a reference point for any scientist involved in related research as well as being a timely summation of what could prove to be a hugely exciting and very fruitful area of inquiry.

How do hormones and growth factors regulate animal growth in the developing embryo and after injury? What processes at the molecular level determine the growth patterns of different tissues? In this diverse synthesis of recent research the regulation of growth in response to environmental and genetic stimuli is discussed at the level of the animal, tissues and cells. Contrasts are drawn between regulation in foetal and adult tissues, and in different tissues such as the CNS, bone and muscle. Functional chapters focus on the molecular links between mechanical tension and muscle growth, for example, while other chapters review the roles of specific molecules such as growth hormone. This state-of-the-art review will be of significant interest to graduate students and research scientists in the fields of animal growth, endocrinology and cell biology.

This field has generated a large amount of controversy of late, mostly because of fierce rivalry between some of the leading workers in the area. This book pulls together a synthetic overview of the field of developmental instability and fluctuating asymmetry, with the participation of the leading laboratories on both sides of the divide. Thereby creating a much needed synthesis of this timely topic in social evolution, mediating some of the disputes in the field.

This book presents a completely novel approach to the understanding of ageing, which many believe is an unsolved problem in biology. It explains why ageing exists in animals, and reviews our understanding of it at the biological level. This includes a discussion of the origins and evolution of ageing. The book is not a review of research on ageing, but instead draws on material from a wide range of disciplines, including the very extensive biomedical information about age-related diseases in humans. Understanding Ageing argues that much research needs to be done on the cellular and molecular aspects of ageing, if the origins of these diseases are to be understood, and their prevention made possible. This thought-provoking book will appeal to all students and researchers who are interested in ageing, whether they are working in the clinical or basic research sphere.

This book presents a completely novel approach to the understanding of ageing, which many believe is an unsolved problem in biology. It explains why ageing exists in animals, and reviews our understanding of it at the biological level. This includes a discussion of the origins and evolution of ageing. The book is not a review of research on ageing, but instead draws on material from a wide range of disciplines, including the very extensive biomedical information about age-related diseases in humans. Understanding Ageing argues that much research needs to be done on the cellular and molecular aspects of ageing, if the origins of these diseases are to be understood, and their prevention made possible. This thought-provoking book will appeal to all students and researchers who are interested in ageing, whether they are working in the clinical or basic research sphere.

Why do we age? Is aging inevitable? Will advances in medical knowledge allow us to extend the human lifespan beyond its present limits? Because growing old has long been the one irreducible reality of human existence, these intriguing questions arise more often in the context of science fiction than science fact. But recent discoveries in the fields of cell biology and molecular genetics are seriously challenging the assumption that human lifespans are beyond our control. With such discoveries in mind, noted cell biologist William R. Clark clearly and skillfully describes how senescence begins at the level of individual cells and how cellular replication may be bound up with aging of the entire organism. He explores the evolutionary origin and function of aging, the cellular connections between aging and cancer, the parallels between cellular senescence and Alzheimer's disease, and the insights gained through studying human genetic disorders--such as Werner's syndrome--that mimic the symptoms of aging. Clark also explains how reduction in caloric intake may actually help increase lifespan, and how the destructive effects of oxidative elements in the body may be limited by the consumption of antioxidants found in fruits and vegetables. In a final chapter, Clark considers the social and economic aspects of living longer, the implications of gene therapy on senescence, and what we might learn about aging from experiments in cloning. This is a highly readable, provocative account of some of the most far-reaching and controversial questions we are likely to ask in the next century.

The rapid development of molecular biology and genetics has led to renewed interest in embryology, comparative embryology, and studies of the relations between ontogeny and phylogeny. In fact, genes have been identified which are involved in the formation of shapes and structures, and it is becoming apparent that their primary morphological expressions are conspicuously similar in different species. The primarily identical shapes do not become diversified until advanced individualization of embryos, and it is here that it is possible to employ the knowledge of comparative embryology, the branch of science engaged in the study of the development and differentiation of tridimensional structures in different animal groups. However, comparative embryology has been neglected during the past decades, as its development has appeared to have been completed. In our opinion, the decreased interest in comparative embryology has been caused by the fact that often the time factor was not or could not be respected. In fact, in the case of embryos of wild animals even their ontogenetic age and sometimes the duration of intrauterine development are unknown.

Sex differences are observed in various physiological, behavioral, and psychic functions, including reproductive behavior, aggres sion, emotions, and cognition. Such differences are expressed even in early childhood with preferences to definite activities. It has been generally accepted that differences between genders are formed under the influence of biological as well as environmental factors. The existence of sex differences in functions of the central nervous system has suggested that there are also morphological sex differences. In recent years several reports on sexual dimorphism in the brain of vertebrates have been published. However, the mecha nisms of sexual differentiation of the central nervous system remain unclear in most cases. It is often difficult to correlate morphological sex differences to differences in definite function or behavior. We set out to explore the sexual dimorphism of the limbic system and especially the bed nucleus of the stria terminalis and the amygdala, which are considered generally to be occupied with the control of reproductive behavior and autonomic and compli cated psychic functions. Several reports on sexual dimorphism of these structures have been published. Some of them have been directed to the total neuronal number and the volume of the nuclei, while others have concentrated on definite subpopula tions of neurons. In many cases the mechanisms of sexual differ entiation were tested, but sometimes they could not be estab lished."

Development of the shapes of living organisms and their parts is a field of science in which there are no generally accepted theoretical principles. What form these principles are likely to take, when they emerge, is a subject in which there is a wide gulf of disagreement between physical scientists and experimental biologists. This book contains both an extensive philosophical commentary on this dichotomy in views and an exposition of the type of theory most favoured by physical scientists. In this theory living form is a manifestation of the dynamics of chemical change and physical transport or other physics of spatial communication. The reaction-diffusion theory, as initiated by Turing in 1952 and since elaborated by Prigogine and by Gierer and Meinhardt among others, is discussed in detail at a level that requires a good knowledge of a first course in calculus, but no more than that.

Drawing on state-of-the-art cellular and molecular techniques as well as new and sophisticated imaging and information technologies, this comprehensive, three-volume collection of cutting-edge protocols provides readily reproducible methods for studying and analyzing the events of embryonic development. volume 1 (ISBN: 089603-574-3) contains techniques for establishing and characterizing several widely used experimental model systems, for the study of developmental patterns and morphogenesis, and for the examination of embryo structure and function. There are also step-by-step methods for the analaysis of cell lineage, the production and use of chimeras, and the experimental and molecular manipulation of embryos, including the application of viral vectors. volume 2 (ISBN: 0-89603-575-1) describes state-of-the-art methods for the study of organogenesis, the analysis of abnormal development and teratology, the screening and mapping of novel genes and mutations, and the application of transgenesis, including the production of transgenic animals and gene knockouts. No less innovative, volume 3 (ISBN: 0-89603-576-X) introduces powerful techniques for the manipulation of developmental gene expression and function, the analysis of gene expression, the characterization of tissue morphogenesis and development, the in vitro study of differentiation and development, and the genetic analysis of developmental models of diseases. Highly practical and richly annotated, the three volumes of Developmental Biology Protocols describe multiple experimental systems and details techniques adopted from the broadest array of biomedical disciplines.

The technique of allometry investigates the effects of size on such variables as food intake, energy requirements, growth rates and age at first reproduction. This book, now available in paperback, brings together much of what is known about the consequences of size and provides a new and mathematically rigorous framework within which many quantitative predictions are made and tested using published and unpublished data. New explanations are proposed for many previously unexplained phenomena such as why in some species females are thousands of times heavier than males, whereas in no species are males more than about eight times heavier than females. The models presented afford a new synthesis of the effects of size and open up more pathways for further theoretical investigation and experimental testing. Care has been taken to give verbal presentations of all the mathematical conclusions to ensure that the text is widely intelligible.

This is the first book that attempts to bring together what is known about the fundamental mechanisms that underlie the development of the cortex in mammals. Ranging from the emergence of the forebrain from the neural plate to the functioning adult form, the authors draw on evidence from several species to provide a detailed description of processes at each stage. Where appropriate, evidence is extrapolated from non-mammalian species to generate hypotheses about mammalian development. In contrast to other texts of developmental biology, Mechanisms of Cortical Development integrates information on regulatory processes at the levels of molecules, cells and metworks. The authors draw together an extensive literature on cellular development and structural morphology, biochemical and genetic events and hypotheses that have been subject to mathematical modelling. Important metholdogies, such as transgenics and formal modelling, are explained for the non-specialist. Major future challenges are clearly identified. This is a unique contribution to the literature, combining the fundamentals of experimental developmental neurobiology with accessible neural modelling. It will be essential reading for neuroscientists in general as well as those with a particular interest in development.

The past decade has seen a dramatic increase in our understanding of early animal development. The revised edition of this excellent book describes the results of this revolution and explains in detail how the body plan of an embryo emerges from a newly fertilized egg. The book starts with a critical discussion of embryological concepts, and with simple mathematics describes cell states, morphogen gradients, and threshold responses. The experimental evidence of the mechanisms of regional specification in vertebrates, insects, and selected invertebrates, namely frogs (Xenopus), mice, chicks, fruitflies (Drosophila), mollusks, ringed worms, sea squirts, and nematode worms (Caenorhabditis), is then discussed. The progress with Drosophila has been particularly impressive, and there is an entire chapter devoted to it that provides a clear guide to the subject and includes a new table of developmentally important genes. Throughout, the emphasis is on conceptual clarity and unity, and the book brings together mathematical models, embryological experiments, and molecular biology in a single comprehensible and coherent account.

Morphogeny of the nasal skull was investigated in 92 embryos of 13 species of Cetacea. Compared to the original nasal capsule of land mammals, the nasal structures of Cetacea show many weighty transformations. As a result, the nostrils are translocated from the tip of the snout to the vertex of the head. Several structures of the embryonic nasal skull remain preserved even in adult cetaceans. The translocation of the nostrils to the highest point of the surfacing body is among the most perfect adaptations of cetaceans to the aquatic life habits. The morphogeny of the nasal skull suggests that all cetaceans are of common origin and form a single monophyletic order. The hitherto usual division of this order into two suborders, Mysticeti and Odontoceti, appears to be unsubstantiated. Rather, at least three closely related superfamilies should be distinguished within the order Cetacea, viz., Balaenopteroidea, Physeteroidea, and Delphinoidea. The results are in a

Plants are an advantageous group for the consideration of the development of biological form. Plants share most aspects of cell biology with other organisms, yet their embryonic development continues throughout their life, their cells do not move relative to each other and their structure is relatively simple. The chapters in this book are centred around the structure of tissues and its purpose is to try and predict what should be looked for at a molecular level so as to account for observable forms. Each chapter deals with a defined problem such as the role of hormones as correlative agents, tissue polarization, apical meristems and cell lineages. The final chapter develops an alternative approach to the problem of the specification of biological form, that of 'epigenetic selection'. The chapters are centred around the structure of tissues, an intermediate and neglected level between overt morphology and biochemistry, and will be of great interest to all those engaged in attempting to understand the principles behind plant development.

Drawing on state-of-the-art cellular and molecular techniques as well as new and sophisticated imaging and information technologies, this comprehensive, three-volume collection of cutting-edge protocols provides readily reproducible methods for studying and analyzing the events of embryonic development. Volume 1 (ISBN: 089603-574-3) contains techniques for establishing and characterizing several widely used experimental model systems, for the study of developmental patterns and morphogenesis, and for the examination of embryo structure and function. There are also step-by-step methods for the analaysis of cell lineage, the production and use of chimeras, and the experimental and molecular manipulation of embryos, including the application of viral vectors. Volume 2 (ISBN: 0-89603-575-1) describes state-of-the-art methods for the study of organogenesis, the analysis of abnormal development and teratology, the screening and mapping of novel genes and mutations, and the application of transgenesis, including the production of transgenic animals and gene knockouts. No less innovative, volume 3 (ISBN: 0-89603-576-X) introduces powerful techniques for the manipulation of developmental gene expression and function, the analysis of gene expression, the characterization of tissue morphogenesis and development, the in vitro study of differentiation and development, and the genetic analysis of developmental models of diseases. Highly practical and richly annotated, the three volumes of Developmental Biology Protocols describe multiple experimental systems and details techniques adopted from the broadest array of biomedical disciplines.

This work is a brief review of the pre- and postnatal development in the North American opossum (Didelphis virginiana) presented in two volumes. Volume I summarizes gametes and fertilization, blastocyst formation and early organogenesis, fetal membranes and placentation, parturition and migration to the pouch, general postnatal growth and development, and histogenesis/organogenesis of the integument, musculoskeletal system, cardiovascular system, blood and blood forming organs, lymphatic organs, nervous system, eye, and ear. Volume II summarizes the histogenesis/organogenesis of the respiratory, digestive, urinary, male and female reproductive and classical endocrine systems.

Due to their pronounced intraspecific variability and to difficulties in defining their evolutionary trends in mammalian phylogenies, peripheral blood vessels have been neglected in comparative studies. Supported by the Sonderforschungsbereich 89 (Car- diology) of the Deutsche Forschungsgemeinschaft, we have reconstructed the ontoge- of the blood vessels of the tree shrew, Tupaia belangeri, on the netic morphogenesis basis of a series of developmental stages. The arteries of the lower extremity are described and discussed here. Besides describing the morphogenesis of the arteries in Tupaia, it is the aim of this study to explain the variability of the arteries of the pelvic extremity among mammals, and especially among primates including man, on the basis of a common developmen- tal pattern. This can be shown in the following example. In the popliteal region of most adult mammals the arteria poplitea profunda is situated under the musculus popliteus. In the adult Tupaia, as well as in primates, this artery is missing but, superficial to the musculus popliteus, an arteria poplitea super- ficialis exists. It seems difficult to explain such a case of "discontinuous evolution," because it is hard to imagine the position of the artery should have shifted through the muscle. The present investigation and the literature show that early in the embryonic development of a primate, man, and of Tupaia, both the arteria poplitea profunda and the arteria poplitea superficialis are present.

This work is a brief review of the pre- and postnatal development in the North American opossum (Didelphis virginiana) presented in two volumes. Volume I summarizes gametes and fertilization, blastocyst formationan and early organogenesis, fetal membranes and placentation, parturition and migration to the pouch, general postnatal growth and development, and histogenesis/organogenesis of the integument, musculoskeletal system, cardiovascular system, blood and blood forming organs, lymphatic organs, nervous system, eye, and ear. Volume II summarizes the histogenesis/organogenesis of the respiratory, digestive, urinary, male and female reproductive and classical endocrine systems.

Drawing on state-of-the-art cellular and molecular techniques as well as new and sophisticated imaging and information technologies, this comprehensive, three-volume collection of cutting-edge protocols provides readily reproducible methods for studying and analyzing the events of embryonic development. volume 1 (ISBN: 089603-574-3) contains techniques for establishing and characterizing several widely used experimental model systems, for the study of developmental patterns and morphogenesis, and for the examination of embryo structure and function. There are also step-by-step methods for the analaysis of cell lineage, the production and use of chimeras, and the experimental and molecular manipulation of embryos, including the application of viral vectors. volume 2 (ISBN: 0-89603-575-1) describes state-of-the-art methods for the study of organogenesis, the analysis of abnormal development and teratology, the screening and mapping of novel genes and mutations, and the application of transgenesis, including the production of transgenic animals and gene knockouts. No less innovative, volume 3 (ISBN: 0-89603-576-X) introduces powerful techniques for the manipulation of developmental gene expression and function, the analysis of gene expression, the characterization of tissue morphogenesis and development, the in vitro study of differentiation and development, and the genetic analysis of developmental models of diseases. Highly practical and richly annotated, the three volumes of Developmental Biology Protocols describe multiple experimental systems and details techniques adopted from the broadest array of biomedical disciplines.