Post-transcriptional Regulation of Maternal RNA in Zebrafish PDF Download

Author: Shannon Marie Byrd
Publisher:
ISBN:
Category : Germ cells
Languages : en
Pages : 214

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Author: Florence Louise Marlow
Publisher: Morgan & Claypool Publishers
ISBN: 161504051X
Category : Family & Relationships
Languages : en
Pages : 221

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Book Description
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

Author:
Publisher: Academic Press
ISBN: 0124166121
Category : Science
Languages : en
Pages : 449

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The Maternal-to-Zygotic Transition provides users with an expert accounting of the mechanisms and functions of this transition in a range of animal and plant models. The book provides critical information on how maternal gene products program the initial development of all animal and plant embryos, then undergoing a series of events, termed the maternal-to-zygotic transition, during which maternal products are cleared and zygotic genome activation takes over the developmental control. Maternal gene products program the initial development of all animal and plant embryos These then undergo a series of events, termed the maternal-to-zygotic transition, during which maternal products are cleared and zygotic genome activation takes over developmental control In this book, experts provide their insights into the mechanisms and functions of this transition in a range of animal and plant models.

Author: Sophie Wiszniak
Publisher:
ISBN:
Category : Germ cells
Languages : en
Pages : 192

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"In most organisms, the primordial germ cells are specified and set aside from the surrounding somatic tissues very early in development. Their ability to carry out a gene regulatory program quite distinct from the surrounding somatic cells, and their capacity to specify entire new organisms has made them a focus of many studies that seek to understand how specific transcriptional and translational programs contribute to cell fate. Zebrafish, a vertebrate with external development of the embryo, is currently one of the best animal models for understanding the molecular basis of germ cell specification. Briefly, germ cell specification is dependent on maternally provided cytoplasmic determinants, termed the germ plasm. The germ plasm, is localised to areas of the embryo that will become the germ cells later in development by inheritance the germ plasm through cleavage divisions. A number of mRNA components of the germ plasm have been identified; interestingly many of them encode RNA-binding proteins, and almost all of them have invertebrate and mammalian orthologues. Evidence suggests that these maternally provided mRNA determinants are specifically maintained in the germ cells throughout embryonic development, and at least some of these gene products are essential for germ cell specification. A number of studies have begun to elucidate the molecular mechanisms that allow germ cell specific maintenance of these mRNAs, and also to identify how maternally provided messages destined for the germ cells are destabilised and eliminated in the somatic tissues. For example, the germ cell specific mRNAs nanos and TDRD7 are destabilised in somatic cells through interactions of the 3 ́UTR sequences with the microRNA miR-430. This miR-430-mediated repression is overcome in germ cells through the binding of an RNA-binding protein Dead end (DND) to distinct sites within the nanos and TDRD7 3 ́UTRs. This thesis details a study of the zebrafish orthologue of HuB, a highly conserved RNAbinding protein with expression in neurons, testes and ovaries in adult vertebrates. In zebrafish, HuB mRNA is maternally provided, and is restricted to the germ cells by 24 hours of development; this is the first report to indicate expression of HuB in the germ cells of vertebrates, suggesting a possible role for HuB in germ cell development. Through detailed mutagenesis studies, the HuB 3 ́UTR has been found to contain a set of four destabilising elements, which bring about somatic degradation of the mRNA, and a separate, 30-nucleotide motif that is responsible for germ cell specific stabilisation of the message. None of these identified destabilising elements are targets for miR-430, and thus they represent novel sequence elements for somatic message degradation in zebrafish. Through a candidate screening approach, DAZL, a germ cell specific RNA-binding protein, was identified as being capable of stabilising HuB mRNA. Further-more, DAZL was shown to mediate this stabilisation of HuB mRNA by interacting, either directly or indirectly, with the 30-nucleotide stabilisation element that was indentified in the HuB 3 ́UTR. This elucidation of the mechanisms of germ cell specific expression of the HuB mRNA is an important finding, for it reveals mechanisms of post-transcriptional regulation that are distinct from that of other germ cell specific mRNAs. In summary, the identification of HuB as a germ cell specific mRNA, and the determination of the post-transcriptional mechanisms responsible for this specific expression is an important first step in understanding how HuB and other germ cell specific RNA-binding proteins contribute to germ cell development and function." -- leaf 3.

Author: Malgorzata Kloc
Publisher: John Wiley & Sons
ISBN: 1118492811
Category : Science
Languages : en
Pages : 459

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Frogs from the genus Xenopus have long been used as model organisms in basic and biomedical research. These frogs have helped unlock key fundamental developmental and cellular processes that have led to important scientific breakthroughs and have had practical application in embryology, cancer research and regenerative medicine. Xenopus Development is a vital resource on the biology and development of these key model organisms, and will be a great tool to researchers using these frogs in various disciplines of biological science. Xenopus Development is divided into four sections, the first three highlight key processes in Xenopus development from embryo to metamophosis. These sections focus on the cellular processes, organogenesis and embryo development. The final section highlights novel techniques and approaches being used in Xenopus research. Providing thorough and detailed coverage, Xenopus Development, will be a timely and welcome volume for those working in cell and molecular biology, genetics, developmental biology and biomedical research. Provides broad overview of the developmental biology of both Xenopus laevis and Xenopus tropicalis Explores cellular to systems development in key biomedical model organisms Timely synthesis of the field of Xenopus biology Highlights key biomedical and basic biological findings unlocked by Xenopus

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: T.A. Dettlaff
Publisher: Springer Science & Business Media
ISBN: 1468406825
Category : Science
Languages : en
Pages : 456

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Studies of oogenesis occupy an important place in current in vestigations in developmental biology. Today no one has any doubt whatsoever that oogenesis is not just the prelude to development, but is development itself, and a very essential part of it. These words of an eminent Soviet scientist, B. L. As taurov , taken by T. B. Aizenshtadt as an epigraph to her chapter in this book, make a good epigraph for the entire book. It is now clear that during oogenesis not only vast reserves of ribosomes and mitochondria, of yolk, carbohydrates, and lipids, and of enzymes for protein and nucleic acid synthesis and for carbohydrate and fat metabolism (which ensures the energy supply and metabolism of the oocyte and the developing embryo) are formed, but also long-lived mRNA and proteins are synthesized, which determine both the completion of oocyte maturation and the initial stages of embryonic development. In the last 15-20 years, the use of molecular biology methods, electron microscopy, autoradiography, and microsurgical methods of experimental embryology in studying the pre-embryonic development of animals has greatly increased our knowledge of oogenesis. This has led to the need to systematize the data obtained, to reinter pret old ideas, and to review the results obtained by new research trends which have emerged in the last few years and which are of general biological interest. Such a task was undertaken in the book Sovremennye Problemy Oogeneza (Current Problems of Oogenesis), published in 1977 (in Russian).

Author: Erica Kratz
Publisher:
ISBN:
Category :
Languages : en
Pages : 274

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Author: Alan Trounson
Publisher: Cambridge University Press
ISBN: 1107470293
Category : Medical
Languages : en
Pages : 464

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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.

Author: Alexander John Marsolais
Publisher:
ISBN:
Category :
Languages : en
Pages :

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The maternal-to-zygotic transition (MZT) is a characteristic phase of early metazoan development where control of embryogenesis transitions from products encoded by the mother to those encoded by the zygotic genome. Post-transcriptional regulation (PTR) plays a critical role in the MZT, particularly in the clearance of maternal mRNAs. Mechanisms of maternal transcript decay that rely exclusively on maternal protein factors and function early during the MZT, as well as mechanisms that require zygotic factors and function later during the MZT, have been characterized. The Drosophila embryo has long-served as a model for the MZT. The RNA-binding protein (RBP) SMAUG (SMG) has been shown to function during the early (maternal) phase of degradation. In contrast, computational methods suggest the RBP PUMILIO (PUM) functions in the late (zygotic) phase of maternal mRNA degradation. Such a role is curious as PUM is maternally-contributed and functional during the maternal (early) phase of embryogenesis. I show here that: 1) PUM is required for the degradation of approximately 500 maternal mRNAs during the late (zygotic) wave of degradation; 2) degradation of PUM target mRNAs is likely delayed to the late (zygotic) phase due to the presence of sub-optimal PUM binding sites within these target mRNAs, 3) degradation of PUM targets is dependent on additional factors such as the RBP BRAIN TUMOUR (BRAT) and a core component of the RNAi machinery, ARGONAUTE 1 (AGO1); and 4) a critical function of PUM appears to be clearance of smg mRNA, since in pum mutant embryos SMG protein persists post-MZT and is associated with an inappropriate down-regulation of SMG target transcripts. Taken together, these data support a multi-factorial view of RBP function, in which the activity of a given RBP is determined by other RBPs associated with a particular mRNA.