Oocytes

Eggs of all animals contain mRNAs and proteins that are supplied to or deposited in the egg as it develops during oogenesis. These maternal gene products regulate all aspects of oocyte development, and an embryo fully relies on these maternal gene products for all aspects of its early development, including fertilization, transitions between meiotic and mitotic cell cycles, and activation of its own genome. Given the diverse processes required to produce a developmentally competent egg and embryo, it is not surprising that maternal gene products are not only essential for normal embryonic development but also for fertility. This review provides an overview of fundamental aspects of oocyte and early embryonic development and the interference and genetic approaches that have provided access to maternally regulated aspects of vertebrate development. Some of the pathways and molecules highlighted in this review, in particular, Bmps, Wnts, small GTPases, cytoskeletal components, and cell cycle regulators, are well known and are essential regulators of multiple aspects of animal development, including oogenesis, early embryogenesis, organogenesis, and reproductive fitness of the adult animal. Specific examples of developmental processes under maternal control and the essential proteins will be explored in each chapter, and where known conserved aspects or divergent roles for these maternal regulators of early vertebrate development will be discussed throughout this review. Table of Contents: Introduction / Oogenesis: From Germline Stem Cells to Germline Cysts / Oocyte Polarity and the Embryonic Axes: The Balbiani Body, an Ancient Oocyte Asymmetry / Preparing Developmentally Competent Eggs / Egg Activation / Blocking Polyspermy / Cleavage/ Mitosis: Going Multicellular / Maternal-Zygotic Transition / Reprogramming: Epigenetic Modifications and Zygotic Genome Activation / Dorsal-Ventral Axis Formation before Zygotic Genome Activation in Zebrafish and Frogs / Maternal TGF-β and the Dorsal-Ventral Embryonic Axis / Maternal Control After Zygotic Genome Activation / Compensation by Stable Maternal Proteins / Maternal Contributions to Germline Establishment or Maintenance / Perspective / Acknowledgments / References

This book combines the most recent knowledge on the maternal, i.e. oocyte/egg-specific, molecules and processes. The volume covers the most recent advances in a plethora of subjects such as: maternal transfer of immunity, localized RNAs functions and mechanisms of RNA localization, transcriptional repression of maternal messages, maternal inheritance and maternal role of CRISPR/Cas9-based genome editing, chromatin remodeling and epigenetic modifications, maternal function of nucleosomes, maternal mitochondria and energy supply, role of bacterial symbionts and their maternal transmission, acquisition of oocyte polarity and evolution of maternal effect genes, germ plasm and oosome origin and functions, mechanisms of oocyte activation and soma germ cells communication. Currently, no other book on the market combines such a comprehensive list of subjects in one volume. Moreover, the information provided is a cross-section through oocytes from various invertebrate and vertebrate species, which is another unique feature of this book. The readers, therefore, get a completely new and invaluable perspective on all covered subjects.

This book addresses the growing needs in deciphering the biological processes associated with fish reproduction, in view of the growth of aquaculture and the dwindling natural stocks of commercially important fish. It presents a comprehensive overview on egg production in fish, from the standpoint of the oocyte. With this view in mind, the book includes chapters on oocyte development (oogenesis), hormonal regulation and hormone receptors, formation of the egg envelopes, growth, accumulation of nutrients and maternal transcripts, maturation, hydration, ovulation and fertilization. A special emphasis is placed on using state-of-the-art tools including electron microscopy for discerning the ultra-structure of the follicle and genomic/proteomic tools to fully understand biological basis of fish reproduction. Studies on promoting oocyte maturation, ovulation and spawning in farmed fish and preservation of fish oocytes at low temperatures are also included. The book will appeal to University lecturers, students, research scientists and those associated with culture of fish in freshwater or marine aquaculture.

The human oocyte or egg is the rarest and most rapidly ageing cell in the body, and yet one that is essential for fertility. This book is about the development, biology and pathology of the oocyte, and new technologies to manipulate, enhance, and control fertility. These technologies are paving the way for overcoming infertility, avoiding inherited diseases, and creating genetically engineered animals from embryo stem cells and cloning. This progress would have been impossible without the myriad of scientific and technical developments covered in this book, including the ability to manipulate and fertilize oocytes in vitro. World-leading experts have contributed to the first book for many years on basic and applied science of the egg, its clinical manipulation, and its pivotal role in reproductive medicine and biology. It will be an essential reference for scientists and clinicians in reproductive medicine and animal breeding technology, and everyone involved in treating infertility.

The use of IVM in assisted reproductive technology continues to increase around the world. The major benefit of IVM is that significant numbers of oocytes can be collected from ovaries without recourse to ovarian stimulation. This reduces the costs, time, and risks associated with conventional IVF. Although initially limited to women with polycystic ovary syndrome who were at higher risk of problems following ovarian stimulation, IVM is increasingly used in women with normal ovulatory menstrual cycles. This authoritative text covers the current scientific knowledge of oocyte development and the understanding behind the techniques involved in the clinical application of IVM in assisted reproductive technologies. Short Contents

In recent years increasing numbers of women from wealthy countries have turned to egg donation, egg freezing, and in vitro fertilization to become pregnant, especially later in life. This trend has created new ways of using, exchanging, and understanding oocytes—the reproductive cells specific to women. In The Oocyte Economy Catherine Waldby draws on 130 interviews---with scientists, clinicians, and women who have either donated or frozen their oocytes or received those of another woman---to trace how the history of human oocytes' perceived value intersects with the biological and social life of women. Demonstrating how oocytes have come to be understood as discrete and scarce biomedical objects open to valuation, management, and exchange, Waldby examines the global market for oocytes and the power dynamics between recipients and the often younger and poorer donors. With this exploration of the oocyte economy and its contemporary biopolitical significance, Waldby rethinks the relationship between fertility, gendered experience, and biomedical innovation.

The human egg - the rarest and most rapidly aging cell in the body - is a topic of intense scientific study. Assisted reproduction clinics are constantly vying to improve success rates - choosing the best gametes is a key step in this process. This new edition of what one reviewer of the first edition described as 'possibly the definitive work on the oocyte' covers the development, biology and pathology of the oocyte, and technologies to manipulate, enhance and control fertility. These technologies are used to overcome infertility, avoid inherited diseases, and create genetically engineered embryos from stem cells and cloning. This progress would have been impossible without the myriad of scientific and technical developments covered in this book. The new edition is thoroughly updated and includes major new research on reprogramming, oocyte molecular development, cryopreservation and viability. We are in exciting times for the egg.