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.

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.

Coverage of the field in Instant Notes in Developmental Biology is current and focuses largely on the principles of embryonic development. It is designed to provide a clear summary of the principles of developmental biology in a compact and easily manageable structure.

This manual describes the methodology and applications of microinjection, a powerful technique for transposing material into living cells through needle injection. Information is presented on the techniques principles, the required equipment, preparation of receiving cells and injected material, and the analysis of results. Detailed protocols for a wide range of applications in different cellular systems are included. A large part of the book is also dedicated to the Xenopus laevis oocyte system.

This textbook provides students with knowledge of neurogenetics, neurogenesis, neuronal specification and function, neuronal networks, learning and memory formation, brain evolution, and neurodegenerative diseases. Students are introduced to topics of classical developmental genetics as well as modern molecular and neurogenetic methods. Using a wealth of examples from current research, the textbook takes a strong applied approach. Using animal models such as Drosophila melanogaster and Caenorhabditis elegans as well as mammalian systems, the interrelationships between genes, neurons, nervous systems, and behaviour under normal and pathological conditions are illustrated. The textbook aims encourage students to address biological questions in neurogenetics and to think about the design of their own experiments. It targets primarily master and graduate students in neurobiology, but is also a valuable teaching tool for instructors in these fields.

The studies described here were carried out in the Neuroregul ation Group, Department of Physiology, University of Leiden, the Netherlands. Over the last decade, this group, in close collaboration with the Department of Neurosurgery of the Academic Hospital of Leiden, has studied the development of the central nervous system from a neuroanatomical as well as a clinical perspective. During this period, the expression of several morphore gulators in the developing rat spinal cord was extensively investigated. Parallel studies focused on the development of the spinal cord fiber systems, which was studied by means of the intrauterine use of neuronal tracers. The main goal of these studies was to extend our knowledge about the (normal) generation of the spinal cord and to contribute to the under standing of clinical problems related to regeneration and degeneration in the mammalian central nervous system. The studies on morphoregulators, in particular, appeared to benefit two different scientific areas. Firstly, the correlation between morphoregulator expression patterns and known anatomy contributed to our knowledge about spinal cord development. Secondly, the correlation between morpho regulator expression patterns and known developmental processes may help to understand their precise function(s). This volume of Advances in Anatomy, Embryology and Cell Biology presents these particular studies on the development of the rat spinal cord performed over the last decade. As well as integrating the results of the tracer studies, this volume also provides an update on the development of the rat spinal cord.

The topic of stem cells has a high profile in the media. We've made important advances in our scientific understanding, but despite this the clinical applications of stem cells are still in their infancy and most real stem cell therapy carried out today is some form of bone marrow transplantation. At the same time, a scandalous spread of unproven stem cell treatments by private clinics represents a serious problem, with treatments being offered which are backed by limited scientific rationale, and which are at best ineffective, and at worse harmful. This Very Short Introduction introduces stem cells, exploring what they are, and what scientists do with them. Introducing the different types of stem cells, Jonathan Slack explains how they can be used to treat diseases such as retinal degeneration, diabetes, Parkinson's disease, heart disease, and spinal trauma. He also discusses the important technique of bone marrow transplantation and some other types of current stem cell therapy, used for the treatment of blindness and of severe burns. Slack warns against fake stem cell treatments and discusses how to distinguish real from fake treatments. He also describes the latest scientific progress in the field, and looks forward to what we can expect to happen in the next few years Very Short Introductions: Brilliant, Sharp, Inspiring ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subject quickly. Our expert authors combine facts, analysis, perspective, new ideas, and enthusiasm to make interesting and challenging topics highly readable.

The North American opossum (Didelphis virginiana) generally is regarded as an important animal, phylogenetically. It is considered to represent a prototype marsupial and closely resembles fossil didelphids (Tyndale-Biscoe 1973). Numerous studies concerning the reproductive biology, embryology, and neurobiology of the opossum have been published. More recently, Didelphis has become popular as an animal model for gastroenterological studies because of the remarkable anatomical and physiological similarities of the esophagus as compared to that of man. Most of the studies of early development have concentrated on early cleavage stages and the formation of the three primary germ layers (Hartman 1916, 1919) and fetal membranes (Selenka 1887; McCrady 1938). The ova of Didelphis remain in the oviduct only for about 24 h before entering the uterus. A corona radiata is absent and each oocyte is surrounded only by a perivitel- line space and a zona pellucida (Talbot and DiCarlantonio 1984). During the short transit period, the egg is fertilized by a single spermatozoon (Rodger and Bedford 1982a,b).

The first 1,000 days, from conception to two years of age, is a critical period of growth and development. Exposures to dietary, environmental, hormonal, and other stressors during this window have been associated with an increased risk of poor health outcomes, some of which are irreversible. The book addresses this crucial interval of early life across biological disciplines, linking concepts related to all biological fields to outcomes during the first 1,000 days (e.g. fetal growth and pregnancy outcomes) and beyond (e.g. gut microbiome and cardiovascular disease later in life). The strength of this book lies in its cross-disciplinary nature.

These Notes grew from my research in evolutionary biology, specifically on the theory of evolutionarily stable strategies (ESS theory), over the past ten years. Personally, evolutionary game theory has given me the opportunity to transfer my enthusiasm for abstract mathematics to more practical pursuits. I was fortunate to have entered this field in its infancy when many biologists recognized its potential but were not prepared to grant it general acceptance. This is no longer the case. ESS theory is now a rapidly expanding (in both applied and theoretical directions) force that no evolutionary biologist can afford to ignore. Perhaps, to continue the life-cycle metaphor, ESS theory is now in its late adolescence and displays much of the optimism and exuberance of this exciting age. There are dangers in writing a text about a theory at this stage of development. A comprehensive treatment would involve too many loose ends for the reader to appreciate the central message. On the other hand, the current central message may soon become obsolete as the theory matures. Although the restricted topics I have chosen for this text reflect my own research bias, I am confident they will remain the theoretical basis of ESS theory. Indeed, I feel the adult maturity of ESS theory is close at hand and I hope the text will play an important role in this achievement.

During the last four decades remarkable developments have taken place in instrumentation and techniques for characterizing the microstructure and microcomposition of materials. Some of the most important of these instruments involve the use of electron beams because of the wealth of information that can be obtained from the interaction of electron beams with matter. The principal instruments include the scanning electron microscope, electron probe x-ray microanalyzer, and the analytical transmission electron microscope. The training of students to use these instruments and to apply the new techniques that are possible with them is an important function, which. has been carried out by formal classes in universities and colleges and by special summer courses such as the ones offered for the past 19 years at Lehigh University. Laboratory work, which should be an integral part of such courses, is often hindered by the lack of a suitable laboratory workbook. While laboratory workbooks for transmission electron microscopy have-been in existence for many years, the broad range of topics that must be dealt with in scanning electron microscopy and microanalysis has made it difficult for instructors to devise meaningful experiments. The present workbook provides a series of fundamental experiments to aid in "hands-on" learning of the use of the instrumentation and the techniques. It is written by a group of eminently qualified scientists and educators. The importance of hands-on learning cannot be overemphasized.

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.

Transcription factors are essential mediators of the genetic programs that control development and physiology. This exciting book presents current knowledge of transcription factors from two viewpoints. First, the basic science of transcriptional regulation is discussed. Second, inherited human diseases attributable to mutations in DNA sequences encoding transcription factors or their cognate binding sites are described. Readers are also introduced to the involvement of transcription factors in somatic cell genetic disease (cancer) and epigenetic disease (teratogenesis).

Patterns in Plant Development offers an introduction to the development of the whole plant. It is essentially a factual book that describes the complex phenomena of development in vascular plants. The point of view is structural, and emphasis is placed on the experimental approach to development. The book deals with lower vascular plants (e.g. ferns) as well as seed plants, so that the treatment of the plant, beginning with the embryo and continuing through the phase of secondary growth (the vascular cambium) is presented. The book is written so that anyone who has completed a basic first-year university course in biology or botany will be able to use it without difficulty. Sufficient background information is provided so that the reader is not required to have an extensive technical background.

Gene Regulatory Networks, Volume 139 in the Current Topics in Developmental Biology series, highlights new advances in the field, with this new volume presenting interesting chapters written by an international board of authors. Topics in this release include Mouse hindbrain GRN, Xenopus endoderm GRN - organogenesis, Vertebrate limb GRN, The notochord gene regulatory network in chordate evolution: conservation and divergence from Ciona to vertebrates, Ciona early embryo GRNs, Boolean logic models, Modeling GRN response to morphogen gradient, GRN architecture, Theory of GRN evolution, Evolution of fly segmentation GRNs, GRN evolution in echinoderms, Evolution of network specificity, and more.

The nervous system is particularly fascinating for many biologists because it controls animal characteristics such as movement, behavior, and coordinated thinking. Invertebrate neurobiology has traditionally been studied in specific model organisms, whilst knowledge of the broad diversity of nervous system architecture and its evolution among metazoan animals has received less attention. This is the first major reference work in the field for 50 years, bringing together many leading evolutionary neurobiologists to review the most recent research on the structure of invertebrate nervous systems and provide a comprehensive and authoritative overview for a new generation of researchers. Presented in full colour throughout, Structure and Evolution of Invertebrate Nervous Systems synthesizes and illustrates the numerous new findings that have been made possible with light and electron microscopy. These include the recent introduction of new molecular and optical techniques such as immunohistochemical staining of neuron-specific antigens and fluorescence in-situ-hybridization, combined with visualization by confocal laser scanning microscopy. New approaches to analysing the structure of the nervous system are also included such as micro-computational tomography, cryo-soft X-ray tomography, and various 3-D visualization techniques. The book follows a systematic and phylogenetic structure, covering a broad range of taxa, interspersed with chapters focusing on selected topics in nervous system functioning which are presented as research highlights and perspectives. This comprehensive reference work will be an essential companion for graduate students and researchers alike in the fields of metazoan neurobiology, morphology, zoology, phylogeny and evolution.

This detailed volume presents a variety of animal models that are commonly used to study sepsis and some key procedures to measure specific disease outcomes. The chapters describe well-established surgical and nonsurgical rodent models of sepsis, presented by experts in the field. In addition, the book includes protocols for burn injury and sepsis, modeling the mouse intensive care unit (MICU), and the development of humanized mice, which may be useful tools to increase the translational potential of rodent sepsis research. There is a chapter discussing the use of biomarkers for sepsis diagnosis and prognosis in humans and mice, as well as chapters describing specific methods for biomarker measurement, and the use of analgesics and humane endpoints in rodent sepsis research. Finally, agent-based computational modeling is presented as a valuable complementary approach to study sepsis. Written for the highly successful Methods in Molecular Biology series, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Sepsis: Methods and Protocols serves as an ideal guide for researchers working toward improving the identification and treatment of septic patients.

References ............................................... 59 Subject Index ............................................. 65 6 Introduction The retina as an organ of perception of light, colour, shape and movement has been the subject of numerous and intensive light- and electron-microscopical investigations. To date the interest in these has largely been concentrated on the structure of the ma ture retina and the genesis of its cellular elements. The first exhaustive observations on the development of the retina in vertebrates were made by Babuchin (1863). Using the retinae of chicken embryos, he showed that Millier's radial fibres and the ganglion cells are the first to develop, while the receptor segments are the last. Subsequently, the early differentiation of Millier's radial fibres was often reaffirmed (Cajal, 1893; Meller, 1968; Bhattacharjee and Sanyal, 1975; and others). Furthermore, Babuchin had already indicated that the structural development in the area of the posterior pole is very rapid compared with those regions of the retina which are situated more peripherally. Today, when comparing results of electron-mi croscopical investigations, this fact is of particular importance, since in each case only very limited areas of the retina can be examined. Schultze (1867a, b) pointed out the uniformity of origin and the general classifica tion of light-perceiving elements into inner and outer segments, thus contesting the hitherto generally held opinion that these structures, like the pigment epithelium, ori of the eye cup. In 1881 Ogneff discovered the analogous ginate from the outer leaf mode of formation in birds and mammals."

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Subject Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Author Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 . . . . . . . . . . . 6 Introduction Chondrification of the somitic mesoderm producing the primordia of the vertebrae has been a favourite topic of investigation by those interested in understanding the me chanisms underlying development and differentiation. Study of this tissue involves the investigation of cell proliferation, migration and cytodifferentiation, synthesis of extra cellular matricial products, inductive tissue interactions, and tissue morphogenesi- some of the major unsolved problems of modern developmental biology. The topic is a large one and various aspects have been reviewed in the past, notably by Holtzer (1959; 1961), Lash (1963a), Strudel (1967), Lash (1968a, c), Holtzer (1968), Holtzer and Abbott (1968), Holtzer and Mayne (1973) and Levitt and Dorfman (1974). Feel ing that the time was appropriate for a overview of the whole field of somitic chondro genesis, I have prepared the present monograph. It covers the development of experi mental studies from the initial grafting of somites to avian chorio-allantoic membranes in the 1920's, through the extirpation experiments of the 1940's, the culturing of the 1950's and the search for pure inducers, to the refocussing of attention on the environ ment and matrix procucts which is dominating the studies of the 1970's. Many of the studies have utilized the embryonic chick as the experimental animal."

This study has two related objectives. One is to improve our understanding of the sub- division of the parahippocampal cortex, the other is to investigate the terminal distri- bution of sulphide silver stainable fibre systems (explained below) in this region. The parahippocampal areas (comprising area entorhinalis, parasubiculum, area ret- rosplenialis e and presubiculum) transmit information to and from the hippocampus, a part of the brain which has been the subject of extensive neurobiological research. Much current anatomical work is therefore devoted to the study of the connections of the parahippocampal cortex (see Discussion), an activity which both requires and pro- vides more precise concepts of its subdivision. Recent studies have shown that histochemistry often brings out laminae and areas in this cortical region more clearly than do conventional morphological methods (Storm* Mathisen and Blackstad, 1964; Mellgren and Blackstad, 1967; Geneser Jensen and Blackstad, 1971; Geneser Jensen et aI., 1974 and references therein; Mellgren, 1973 a, b). The sulphide silver method, used here, is particularly valuable in this respect, as will be explained shortly.

The placenta of the guinea-pig has assumed exceptional importance among the discoidal hemochorial placentae since the end of the sixties. Up to that date, numerous studies had been published on the functional analysis of the human placenta. One shortcom- ing common to all these studies, however, was the fact, that the human placenta was not absolutely suitable for morphological research, owing to fIxation difficulties, and for experimental investigations virtually unsuitable. Since other hemochorial villous placentae, like that of the anthropoid apes (primates) were practically unobtainable, a possible alternative was sought among the I;tcunal placentae. The numerous studies on the guinea-pig placenta undertaken at the turn of the century favoured the choice of this organ as it also belonged to the discoidal hemochorial type, like that of man. The fact that its structure was not villous but lacunal and therefore showed a different cir- culation seemed even advantageous in this case. The lacunal system facilitates differen- tiation in morphologically distinct areas, which allow independent functional analysis. The morphological and histochemical studies made during the past decade by Enders (1965), Vollrath (1965), Miiller and Fischer (1968), Kaufmann (1969a), Davidoff and Schiebler (1970a, b), King and Enders (1970b, 1971), Davidoff and Gospodinoff (1971), Davidoff (1973), Kaufmann (1974) have led to the discovery of a large amount of new information on this organ, thus rendering it one of the most precisely examined placentae so far.

The population of the world continues to increase at an alarming rate. The trouble linked with overpopulation ranges from food and water scarcity to inadequacy of space for organisms. Overpopulation is also linked with several other demographic hazards, for instance, population blooming will not only result in exhaustion of natural repositories, but it will also induce intense pressure on the world economy. Today nanotechnology is often discussed as a key discipline of research but it has positive and negative aspects. Also, due to industrialization and ever-increasing population, nano-pollution has been an emerging topic among scientists for investigation and debate. Nanotechnology measures any substance on a macromolecular scale, molecular scale, and even atomic scale. More importantly, nanotechnology deals with the manipulation and control of any matter at the dimension of a single nanometer. Nanotechnology and nanoparticles (NPs) play important roles in sustainable development and environmental challenges as well. NPs possess both harmful and beneficial effects on the environment and its harboring components, such as microbes, plants, and humans. There are many beneficial impacts exerted by nanoparticles, however, including their role in the management of waste water and soil treatment, cosmetics, food packaging, agriculture, biomedicines, pharmaceuticals, renewable energies, and environmental remedies. Conversely, NPs also show some toxic effects on microbes, plants, as well as human beings. It has been reported that use of nanotechnological products leads to the more accumulation of NPs in soil and aquatic ecosystems, which may be detrimental for living organisms. Further, toxic effects of NPs on microbes, invertebrates, and aquatic organisms including algae, has been measured. Scientists have also reported on the negative impact of NPs on plants by discussing the delivery of NPs in plants. Additionally, scientists have also showed that NPs interact with plant cells, which results in alterations in growth, biological function, gene expression, and development. Thus, there has been much investigated and reported on NPs and plant interactions in the last decade. This book discusses the most recent work on NPs and plant interaction, which should be useful for scientists working in nanotechnology across a wide variety of disciplines.

The range of nanomaterial applications has expanded recently from catalysis, electronics, and filtration to therapeutics, diagnostics, agriculture, and food because of unique properties and potentials of different nanoparticles and nanomaterials. Research shows that these exquisite particles can interact with an organism at the cellular, physiological, biochemical, and molecular levels. However, our knowledge of how they affect these changes, selectively or generally, in diverse organism or ecosystems is very limited and far from satisfactory. Data indicate that the biological function largely depends on the shape, size, and surface characteristics of the nanoparticles used besides life cycle stages of an organism. Therefore, this compilation will focus on the body of work carried out by distinguished investigators using diverse nanomaterials and plant and animal species. This book includes specific case studies as well as general review articles highlighting aspects of multilayered interactions, and targets not only research and academic scholars but also the concerned industry and policy makers as well.

The discovery of the reversible red far-red control of plant growth and development and the subsequent in vivo identification and isolation of the photoreceptor pigment, phyto chrome, constitutes one of the great achievements in modern biology. It was primarily a group of investigators at the Plant Industry Station, Beltsville, Mary land, headed by the botanist H.A. BORTHWICK and the physical chemist S.B. HENDRICKS, who made the basic discoveries and developed a theoretical framework on which the current progress in the field of phytochrome is still largely based. While the earlier development of the phytochrome concept has been covered by a num ber of excellent articles by the original investigators [104,105,33,238] as well as by others who joined the field of phytochrome research later [72, 109, 219], a comprehensive and up-to-date treatment of photomorphogenesis is not available at present. Since it seems to be needed for teaching as well as for researchers I have tried to summarize the present state of the field, reviewing the historical aspects of the phytochrome story only insofar as they are required to understand the present situation. The emphasis of my treatment will be on developmental physiology ("photomorphogenesis") rather than on phytochrome per se.

Tackling one of the most difficult and delicate of the evolutionary questions, this challenging book summarizes the more recent results in phylogenetics and developmental biology that address the evolution of key innovations in metazoans. Divided into three sections, the first considers the phylogenetic issues involving this area of the tree of life and the elucidation of those relationships that continue to trouble taxonomists. The second section considers the developmental biology of metazoan evolution including the development of the nervous system, sensory organs, and physiological maturation. Part three focuses on the evolution of pattern and process in the Metazoa.