Download Free Localization Stability And Functional Role Of Sperm Associated Alpha L Fucosidase Book in PDF and EPUB Free Download. You can read online Localization Stability And Functional Role Of Sperm Associated Alpha L Fucosidase and write the review.

Novel isoforms of alpha-L-fucosidase are found in both the seminal plasma and membrane system of human sperm. Association of alpha-L-fucosidase with the human sperm membrane system suggests a role in fertilization. This investigation first refined the subcellular localization of membrane associated alphaL-fucosidase in washed, capacitated, and acrosome reacted human spermatozoa using immunolocalization and confocal microscopy. These experiments revealed sperm associated alpha-L-fucosidase was widely distributed throughout the membrane system of human sperm with enrichment in the equatorial segment. Secondly, this project investigated the functional distribution and stability of alpha-L-fucosidase using fluorometry. If alpha-L-fucosidase is required during fertilization, substantial amounts of the enzyme should be present in acrosome reacted cells and considerable activity should remain for at least 24 hours at body temperature (37°C). Data from direct fluorometric enzyme assays revealed high amounts of alpha-L-fucosidase activity in capacitated and acrosome reacted human sperm that remained actively stable for up to 72 hours. Thirdly, this project evaluated the role(s) of alpha-L-fucosidase in fertilization using a Syrian hamster in vitro system. Two hypotheses were tested using a Syrian hamster model system. The first is alpha-L-fucosidase is required for binding and/or penetration of the zona pellucida (ZP); therefore pretreatment of sperm with DFJ, alpha-L-fucosidase competitor, will inhibit binding and/or penetration of the ZP. No significant difference was found between the average number of tightly bound sperm per oocyte for oocytes inseminated with control or DFJ pre-treated sperm. Additionally, both control and DFJ pre-treated sperm could penetrate the ZP. These results provided direct evidence that sperm associated alpha-L-fucosidase is not required for binding and/or penetration of the zona pellucida. The second hypothesis is alpha-L-fucosidase is required for membrane-membrane fusion between sperm and oocyte, therefore pretreatment of sperm with DFJ will inhibit fertilization at the membrane level. Pre-treatment of sperm with 5 mM DFJ significantly reduced the percent of 2-cell embryos compared to the control group. Taken together, the results indicated sperm associated alpha-L-fucosidase functions during hamster fertilization. Understanding the role of sperm associated alpha-L-fucosidase could lead to the possible development of infertility treatments and/or clinical diagnostic tools for evaluating patient fertility.
Over the last decades, acrosomal exocytosis (also called the “acrosome reaction”) has been recognized as playing an essential role in fertilization. Secretion of this granule is an absolute requirement for physiological fertilization. In recent years, the study of mammalian acrosomal exocytosis has yielded some major advances that challenge the long-held, general paradigms in the field. Principally, the idea that sperm must be acrosome-intact to bind to the zona pellucida of unfertilized eggs, based largely on in vitro fertilization studies of mouse oocytes denuded of the cumulus oophorus, has been overturned by experiments using state-of-the-art imaging of cumulus-intact oocytes and fertilization experiments where eggs were reinseminated by acrosome-reacted sperm recovered from the perivitelline space of zygotes. From a molecular point of view, acrosome exocytosis is a synchronized and tightly regulated process mediated by molecular mechanisms that are homologous to those reported in neuroendocrinal cell secretions. The authors provide a broader perspective, focusing on a limited number of important topics that are essential for understanding the molecular mechanisms governing this step in the fertilization process. They also discuss molecular aspects such as the signaling pathways leading to exocytosis, including the participation of ion channels, lipids, the fusion machinery proteins and the actin cytoskeleton as well as cellular aspects such as the site of acrosomal exocytosis and the use of gene-manipulated animals to study this process.
This book contains the proceedings of the International Symposium on the Mechanisms of Sexual Reproduction in Animals and Plants, where many plant and animal reproductive biologists gathered to discuss their recent progress in investigating the shared mechanisms and factors involved in sexual reproduction. This now is the first book that reviews recent progress in almost all fields of plant and animal fertilization. It was recently reported that the self-sterile mechanism of a hermaphroditic marine invertebrate (ascidian) is very similar to the self-incompatibility system in flowering plants. It was also found that a male factor expressed in the sperm cells of flowering plants is involved in gamete fusion not only of plants but also of animals and parasites. These discoveries have led to the consideration that the core mechanisms or factors involved in sexual reproduction may be shared by animals, plants and unicellular organisms. This valuable book is highly useful for reproductive biologists as well as for biological scientists outside this field in understanding the current progress of reproductive biology.
Biology of Drosophila was first published by John Wiley and Sons in 1950. Until its appearance, no central, synthesized source of biological data on Drosophila melanogaster was available, despite the fly's importance to science for three decades. Ten years in the making, it was an immediate success and remained in print for two decades. However, original copies are now very hard to find. This facsimile edition makes available to the fly community once again its most enduring work of reference.
This valuable reference work provides a synthesis of the latest knowledge about the acrosomatic reaction of human sperm. The acrosomatic reaction, which is a fundamental step in the process of fertilisation, is examined on both the fundamental and clinical levels. Three very recent aspects are also dealt with: what happens to the acrosome during intracytoplasmic microinjections, the usefulness of screening spermatozoa that have completed their acrosomatic reaction, and the development of contraception by a vaccine that targets one of the proteins of the acrosome. International Symposium, Collioure, France, September 1995.
Genomics is a rapidly growing scientific field with applications ranging from improved disease resistance to increased rate of growth. Aquaculture Genome Technologies comprehensively covers the field of genomics and its applications to the aquaculture industry. This volume looks to bridge the gap between a basic understanding of genomic technology to its practical use in the aquaculture industry.
The Causes and Consequences of Chromosomal Aberrations explores one of the most dramatic examples of genomic instability-chromosomal aberrations. It describes some of the more recent techniques used to map genes within the human genome, study chromosomal aberrations at the cellular level, and define the organization of the interphase nucleus. General overviews are provided to build a conceptual framework for understanding the generality and specificity of chromosomal aberrations. The Causes and Consequences of Chromosomal Aberrations also explores the role of recombinases and topoisomerases in the development of chromosomal aberrations. It contains studies of chromosomal aberrations, which offer separate instructive treatises on specific malignancies. The Causes and Consequences of Chromosomal Aberrations is useful to medical and graduate students, physicians, molecular biologists, and cytogeneticists. It will benefit anyone interested in the concepts, contributions, and development in the field of molecular cytogenetics.
This book reviews the state of knowledge and progress of research on food proteins, and in particular, milk proteins. Its basis is the Symposium on Milk Proteins that was held at the Federal Dairy Research Centre in Kiel, FRG, in June, 1988. Scien tists from around the world attended and addressed pure, as well as applied fields of protein research and technology. This book is divided into five sections, each adapted from the symposium's invited lectures, short communications, and poster presentations. New criteria for the "bio logical value" of dietary proteins and their relationships are considered according to: - Milk Proteins and Nitrogen Equilibrium - Milk Proteins and Ligands - Milk Proteins: Structural and Genetic Aspects - Milk Proteins: Technological and Functional Aspects - Milk Proteins and Clinical Nutrition Generally, different dietary proteins are classified according to their "biological value," i.e., their capacity to cause different retention of nitrogen in the body. But we think there are other intriguing leads worth studying that may help to identify which dietary proteins are best recommended for specific dietary situations or clini cal conditions. In addition, we have taken into consideration new fields such as attempts to determine the three-dimensional structure of proteins using two-dimensional NMR spectroscopy, and the application of genetic engineering to the lactating cell. In other words, we are on the way to the transgenic cow with customized milk constituents and composition.