Experimental Approaches To Mammalian Embryonic Development

Recent advances in the experimental analysis of the mammalian embryo are discussed from various scientific perspectives in this summary of major breakthroughs in embryonic development.

Developmental biology has been transformed recently by discoveries in the fields of molecular biology, cell biology, and immunology. New ways of manip ulating mammalian development are uncovering control mechanisms and ena bling us to apply them in solving practical problems in animal production and human health. This book outlines some of these new manipulations and how they have contributed to the present state of developmental biology. Chapter 1 describes gene transfer by micro injection of cloned recombinant DNA into zygotes. Although the factors that affect transformation frequencies and integration sites are still unknown, such techniques offer a number of exciting prospects. Research models for human disease coula be artificially created and desirable characteristics in agricultural animals could be - hanced. . The theme of cell-to-cell transfer is continued in Chapters 2 and 3. Chapter 2 describes pronuclear transplantation by Sendai virus-induced fusion of the karyoplast with the enucleated embryo. Using this procedure, it has been dem onstrated that both male and female genomes are essential for normal develop ment, although the reason for this is not yet understood. Chapter 3 describes studies on the fusion of whole oocytes. .

Methods in Mammalian Reproduction presents some of the techniques for manipulating, analyzing, observing, testing, and generally experimenting with mammalian mothers and their gametes and embryos. Mammalian reproduction involves an intimate relationship between mother and embryo. The first 18 chapters are arranged in an order that follows a developmental sequence from oocyte to fetal organs and the remaining seven chapters deal with the maternal side of the relationship. With strong focus on laboratory rodents and lagomorphs, the book starts with an introduction to in vitro oocyte maturation and experimental production of mammalian parthenogenetic. It goes on to describe the microtechniques in pre-implantation of embryos, production of chimeras, techniques for early embryonic tissue separation, mammalian embryo preservation by freezing, and in vitro development of whole mouse embryos beyond the implantation stage. Chapters 11-15 discuss the in vitro implantation of mouse blastocysts, advances in rabbit embryo and in large mammal embryo cultures, embryo transfer in large domestic mammals, and manipulation of marsupial embryos and pouch young. The following chapters cover reproduction experiments using marsupials, domestic farm species, and primates including humans. Finally, the concluding chapters tackle the use of amniocentesis in prenatal diagnosis, collection and analysis of female genital tract secretions, analysis of antifertility action of intrauterine devices, and surgical induction of endometriosis. This book will be helpful to students, teachers, researchers, and clinical researchers who demand for more and better procedures for analysis of mammalian reproduction.

Cell Fate in Mammalian Development, Volume 128, the latest release in the Current Topics in Developmental Biology series, provides reviews on cell fate in mammalian development. Each chapter is written by an international board of authors, with this release including sections on the Specification of extra-embryonic lineages during mouse pre-implantation development, Cell polarity and fate specification, The circuitry that drives trophectoderm identity, Breaking symmetry and the dynamics of transcription factors directing cell fate specification, Mechanics and cell fate, How physical properties of cells change in development and their effect on cell fate decisions, and more.

Recent scientific breakthroughs, celebrity patient advocates, and conflicting religious beliefs have come together to bring the state of stem cell researchâ€"specifically embryonic stem cell researchâ€"into the political crosshairs. President Bush's watershed policy statement allows federal funding for embryonic stem cell research but only on a limited number of stem cell lines. Millions of Americans could be affected by the continuing political debate among policymakers and the public. Stem Cells and the Future of Regenerative Medicine provides a deeper exploration of the biological, ethical, and funding questions prompted by the therapeutic potential of undifferentiated human cells. In terms accessible to lay readers, the book summarizes what we know about adult and embryonic stem cells and discusses how to go about the transition from mouse studies to research that has therapeutic implications for people. Perhaps most important, Stem Cells and the Future of Regenerative Medicine also provides an overview of the moral and ethical problems that arise from the use of embryonic stem cells. This timely book compares the impact of public and private research funding and discusses approaches to appropriate research oversight. Based on the insights of leading scientists, ethicists, and other authorities, the book offers authoritative recommendations regarding the use of existing stem cell lines versus new lines in research, the important role of the federal government in this field of research, and other fundamental issues.

Scientific Frontiers in Developmental Toxicology and Risk Assessment reviews advances made during the last 10-15 years in fields such as developmental biology, molecular biology, and genetics. It describes a novel approach for how these advances might be used in combination with existing methodologies to further the understanding of mechanisms of developmental toxicity, to improve the assessment of chemicals for their ability to cause developmental toxicity, and to improve risk assessment for developmental defects. For example, based on the recent advances, even the smallest, simplest laboratory animals such as the fruit fly, roundworm, and zebrafish might be able to serve as developmental toxicological models for human biological systems. Use of such organisms might allow for rapid and inexpensive testing of large numbers of chemicals for their potential to cause developmental toxicity; presently, there are little or no developmental toxicity data available for the majority of natural and manufactured chemicals in use. This new approach to developmental toxicology and risk assessment will require simultaneous research on several fronts by experts from multiple scientific disciplines, including developmental toxicologists, developmental biologists, geneticists, epidemiologists, and biostatisticians.

The book considers signaling events from the zygote embryo through to the blastocyst with relevant data from embryonic stem (ES) cells, including dialogue with the extracellular environment and with the maternal tract during the implantation process. Application of the knowledge described to improve the success of human and animal assisted conception is considered where appropriate, but the focus is largely on fundamental rather than applied cell/molecular biology, as this is the area that has historically been neglected. While the general features of metabolism during preimplantation development are well established, especially in terms of nutrient requirements, uptake and fate, remarkably little is known about early embryo signaling events, intracellular or intercellular, between individual embryos in vitro or with the female reproductive tract in vivo. This contrasts with the wealth of information on cell signaling in somatic cells and tissues, as a glance at any textbook of biochemistry illustrates. This lack of information is such that our understanding of the molecular cell biology of early embryos -- a prerequisite to defining the mechanisms which regulate development at this critical stage of the life cycle -- is seriously incomplete. This volume is the first to address this issue by describing the current state of knowledge on cell signaling during mammalian early embryo development and highlighting priority areas for research.

"A subject collection from Cold Spring Harbor perspectives in biology."