OECD Guidelines for the Testing of Chemicals, Section 2 Test No. 231: Amphibian Metamorphosis Assay


Book Description

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 ...




Amphibian Metamorphosis


Book Description

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.




Metamorphosis


Book Description

Metamorphosis addresses various facets of postembryonic development, particularly signal transduction, morphogenesis, cell-cell interactions, and programmed cell death. A key feature of the book is its exploration of the molecular mechanisms underlying these processes. - Hormonal regulation of development - The mechanisms of hormone action - The steroid/thyroid hormone receptor family - Morphogenesis and programmed cell death







Nitrogen Metabolism and Excretion


Book Description

Although the basic evolutionary patterns of nitrogen metabolism and excretion have been outlined for decades, there has been a resurgence of research activity in the past 15 years. Research in nitrogen metabolism has been stimulated in the area of acid-base balance. The molecular revolution has had an impact on the field as well, and recent studies on nitrogen metabolism and excretion now almost routinely use the tools of molecular biology. Of special interest are recent studies of evolutionary relationships between proteins of nitrogen metabolism. Nitrogen Metabolism and Excretion updates the reader on progress being made in this subject, offering an exciting integration of traditional topics and discussions on the most recent issues which have not yet appeared in other textbooks or references. The book features chapters on the latest developments in nitrogen metabolism and excretion from 28 prominent researchers from all over the world. Each chapter is detailed and specific, filled with useful concepts and techniques. The scope of the book is broad and diverse, covering groups from invertebrates to mammals, and subjects from nitrogen in oceanic buoyancy regulation to molecular mechanisms of nitric oxide synthesis. The text provides a phylogenetic view of various animal groups and presents much new information intended to break down phylogenetic stereotypes. The general areas of development, maternal-fetal interactions, protein turnover, carbamoyl phosphate synthesis, nitric oxide, and nitrates and nitrites are also covered in depth. This volume is the first in a new series that brings about a modern synthesis of areas of animal physiology. Nitrogen Metabolism and Excretion benefits both established researchers interested in nitrogen and advanced undergraduate and graduate students who want to investigate the most current and exciting questions being studied and debated.







Metamorphosis in Fish


Book Description

This book gathers current data on the two types of fish metamorphoses and their endocrine controls. It will be of interest for fish biologists as well as comparative physiologists and endocrinologists. Metamorphosis is a major developmental phase characterized by morphological and physiological changes. It prepares organisms for a drastic shift in habitat and behavior. Among vertebrates, besides the well-known larval metamorphosis in amphibians, two types of metamorphosis are also described in the life cycle of some fish species. Larval metamorphosis, also called first metamorphosis or true metamorphosis, is encountered in lampreys, representative species of basal vertebrates as well as in some teleost groups, elopomorphs and pleuronectiforms, and possibly also in some other teleost species. Secondary metamorphosis occurs in juveniles of some diadromic migratory teleosts, such as salmons and eels, and compared to larval metamorphosis, involves less drastic morphological changes.







Wildlife Review


Book Description