In an age when advanced molecular and genetic tools allow studies in various systems, amphibian metamorphosis still offers perhaps the most accessible model for the study of postembryonic organogenesis and mechanisms of hormonal regulation during vertebrate development. Amphibian Metamorphosis: From Morphology to Molecular Biology integrates findings from the most recent research with earlier observations, providing molecular and mechanistic insights into the signal transduction pathways underlying tissue-specific transformations during metamorphosis. The author, renowned expert of anuran metamorphosis and Head of the Unit of Molecular Morphogenesis at NICHD/NIH, begins with an overview of metamorphosis in different classes of amphibians and various factors that influence this process. A review of earlier morphological, cellular, and biochemical changes focuses on organs and tissues that have been studied extensively at the molecular level, while discussion of the thyroid hormone signal transduction pathway emphasizes transcriptional regulation mechanisms by thyroid receptors. The book provides a summary and comparison of gene regulation programs induced by thyroid hormone in several organs that undergo distinct metamorphic transformations. Several chapters are devoted to functional and mechanistic implications of the molecular findings on the thyroid hormone response genes in tissue transformation. Special features of this book include: * An emphasis on integrating the morphological approach with molecularand cell biology * A historical perspective on the progression from discovery of the thyroid hormone to present-day research advances * Comparisons of amphibian and insect metamorphosis * Dozens of instructive photographs, several in full color Amphibian Metamorphosis: From Morphology to Molecular Biology is a unique and invaluable resource for professionals and aspiring professionals in develop-mental biology, molecular biology, cell biology, evolutionary biology, and endocrinology.

This Test Guideline describes an amphibian metamorphosis assay intended to screen substances which may interfere with the normal functioning of the hypothalamo-pituitary-thyroid axis. The assay was validated with the species Xenopus laevis, which is ...

The papers in this volume were presented at an international symposium, held in South Australia on September 8-10, 1983. The purpose of the meeting was to present the comparative physiology of gas exchange, water balance and energet ics of developing vertebrate embryos. contributions were invited from leading research workers in an attempt to represent the forefront of investigation of all vertebrate classes and to promote a broadly comparative approach to the study of embryonic physiology. These proceedings therefore reflect the current level of research activity focus ing on each group of vertebrates. While considerable expansion and specializa tion has occurred in the area of avian embryos over the last decade, work on reptilian embryos is less developed and that on fish and amphibians is still in its infancy. Although a great deal is known about respiration and metabolism in embryos of placental mammals, the physiology associated with the curious mode of development of monotreme and marsupial embryos has not been examined until recently. In this symposium. the well-studied vertebrate classes are repre sented primarily by specific research papers that document original work. These are balanced by more extensive reviews of the lesser known classes.

In our own juvenile stage, many of us received our wide-eyed introduction to the wonders of nature by watching the metamorphosis of swimming tadpoles into leaping frogs and toads. The recent alarming declines in amphibian populations worldwide and the suitability of amphibians for use in answering research questions in disciplines as diverse as molecular systematics, animal behavior, and evolutionary biology have focused enormous attention on tadpoles. Despite this popular and scientific interest, relatively little is known about these fascinating creatures. In this indispensable reference, leading experts on tadpole biology relate what we currently know about tadpoles and what we might learn from them in the future. Tadpoles provides detailed summaries of tadpole morphology, development, behavior, ecology, and environmental physiology; explores the evolutionary consequences of the tadpole stage; synthesizes available information on their biodiversity; and presents a standardized terminology and an exhaustive literature review of tadpole biology.

Consisting of more than six thousand species, amphibians are more diverse than mammals and are found on every continent save Antarctica. Despite the abundance and diversity of these animals, many aspects of the biology of amphibians remain unstudied or misunderstood. The Ecology and Behavior of Amphibians aims to fill this gap in the literature on this remarkable taxon. It is a celebration of the diversity of amphibian life and the ecological and behavioral adaptations that have made it a successful component of terrestrial and aquatic ecosystems. Synthesizing seventy years of research on amphibian biology, Kentwood D. Wells addresses all major areas of inquiry, including phylogeny, classification, and morphology; aspects of physiological ecology such as water and temperature relations, respiration, metabolism, and energetics; movements and orientation; communication and social behavior; reproduction and parental care; ecology and behavior of amphibian larvae and ecological aspects of metamorphosis; ecological impact of predation on amphibian populations and antipredator defenses; and aspects of amphibian community ecology. With an eye towards modern concerns, The Ecology and Behavior of Amphibians concludes with a chapter devoted to amphibian conservation. An unprecedented scholarly contribution to amphibian biology, this book is eagerly anticipated among specialists.

This book came about as a result of a review I had written earlier on fea tures of cellular changes occurring during anuran metamorphosis. Only a limited treatment of this subject was possible in such a circumscribed work and only specific examples of organic change were dealt with. Thus the sins of omission weighed heavily, for so much information could not be included to provide a more comprehensive and authenticated account of the elaborate, complex, and far-reaching changes that an aquatic larva undergoes to become a terrestrial froglet. A good deal of my working life has been spent investigating amphib ians, especially their larval developmental morphology during metamor phosis, first at the level of light microscopy and in later years by electronmicroscopy. Initially I was particularly concerned with morpho logical homologies of a variety of larval structures, such as the cranial and pharyngeal skeleton and the nerves and musculature, in order to learn more about amphibian phylogeny, for during my pre-and early postgrad uate years G. R. Beer and D. M. S. Watson inspired an undying interest in and respect for vertebrate comparative anatomy. However, it now seems to be that amphibian phylogenetic relationships are best dealt with by the paleontologists, so ably demonstrated by D. M. S. Watson and A. S. Romer and the contemporary enthusiasts in this field like A. L. Panchen, R. L. Carroll, E. Jarvik, and K. S. Thompson among a host of others, particularly in the USA.