Download or read book The Effects of Sterols on Drosophila Melanogaster written by Angela M. Martin and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Sterols are essential components of cellular membranes and are required precursors for important hormones regulating growth and development. Unlike most animals, insects lack the ability to synthesize sterols de novo and they must acquire sterols from their food. Cholesterol is the typical sterol recovered from animals, including most insects. Plant and fungal sterols differ structurally from cholesterol, mostly in side chain configuration and the number and position of double bonds. In the lab, Drosophila are reared on diets that contain 4 different sterols -- cholesterol (animal sterol), sitosterol and stigmasterol (plant sterols), plus ergosterol (fungal sterol); ergosterol comprises nearly 75% of the dietary sterol content. Like vertebrates, Drosophila requires cholesterol for membrane structure and hormone production. However, their inability to synthesize sterols de novo makes them a model organism to study sterol use and metabolism. Two experiments were performed. First, using a recently developed holidic diet, larvae were individually reared (from hatch) on each of the 4 different sterols in standard Drosophila diet, each at a range of different concentrations. When individual sterols are incorporated at different concentrations into a holidic diet, performance and overall survival are significantly affected. Individuals reared on cholesterol only diets exhibited significantly faster developmental times to pupation and also to eclosion from pupation; additionally, overall survival to pupation and eclosion was significantly increased compared to sitosterol, stigmasterol, and ergosterol. In the absence of sterols, individuals arrested development. As an individual sterol ergosterol minimally supported adult survival at low concentrations and failed to support survival at high concentrations. Next, the extent to which sparing occurs in Drosophila melanogaster was examined using different cholesterol and ergosterol ratios in the diet. When ergosterol was supplemented with cholesterol in different ratios, survival was dramatically improved and in some instances exceeded that of only cholesterol. Survival to pupation was significantly reduced as the ratio of cholesterol increased. Collectively the results show that slight variations in sterol structure have pronounced effects on Drosophila growth and development, and that a small amount of dietary cholesterol, likely for metabolic purposes, is required. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/155605.
Download or read book Sterol Requirements in Drosophila Melanogaster written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Sterol is an abundant component of eukaryotic cell membranes and is thought to influence membrane properties such as permeability, fluidity and microdomain formation. Drosophila is an excellent model system in which to study functional requirements for membrane sterol because, although it does not synthesize sterol, it nevertheless requires sterols to complete development. Moreover, Drosophila normally incorporates sterols into cell membranes. Thus, dietary sterol depletion can be used to specifically reduce membrane sterol levels. In contrast, vertebrates do synthesize cholesterol. In this way, sterol depletion in vertebrates demand the use of approaches such as chemical extractions, drug treatments or genetic manipulation which are prone to have side effects. We have controlled the level and type of dietary sterol available to developing Drosophila larvae in order to investigate the requirement for sterol in cell membranes, and to distinguish it from the function of sterol as a precursor for signaling molecules. Strikingly, we show that membrane sterol levels can be reduced 6-fold in most tissues without affecting cell or larval viability. Larvae respond to sterol depletion by arresting their growth and development, and by increasing the level of specific sphingolipid variants that promote survival when sterol is scarce. Thus, non-sterol lipids are able to substitute for sterols in the maintenance of basic membrane biophysical properties required for life. Despite this, Drosophila larvae regulate their growth to maintain membrane sterol levels within tight limits. The existence of this novel membrane sterol-dependent growth control mechanism indicates an important role for bulk membrane sterol in the tissue specific functions of differentiated cells.
Download or read book Developmental Timing written by and published by Academic Press. This book was released on 2013-09-04 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new volume of Current Topics in Developmental Biology covers developmental timing, with contributions from an international board of authors. The chapters provide a comprehensive set of reviews covering such topics as the timing of developmental programs in Drosophila, temporal patterning of neural progenitors, and environmental modulation of developmental timing.
Download or read book Sterol Regulation of Ion Channels written by and published by Academic Press. This book was released on 2017-08-29 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sterol Regulation of Ion Channels, Volume 80, the latest in the Current Topics in Membranes series provides outstanding content to the scientific community on relevant topics that relate to the broad field of membranes. Topics of note in this new release include Membrane structure and general mechanisms of sterol regulation of ion channels, the Regulation of ion channels by sterols as boundary lipids, the Differential effects of sterols on ion channels: specific vs. non-specific interactions, the Structural determinants of cholesterol-ion channels interactions, and the Regulation of Ca2+-sensitive K+ channels by cholesterol and bile acids via distinct channel subunits and sites, amongst other specialized chapters. The serial is targeted towards scientists and researchers in biochemistry and molecular and cellular biology, providing the necessary membrane research to assist them in discovering the current state of a particular field. The authors and editors associated with the Current Topics in Membranes series are recognized as world-renowned scientists in their respective fields, making CTM one of the premier serials on membranes Contains original material, both textual and illustrative, that make it a very relevant reference Presented in a very comprehensive manner Ideal for both researchers in the field and general readers
Download or read book Biochemistry and Function of Sterols written by Edward J. Parish and published by CRC Press. This book was released on 2020-11-25 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Leading international scientists bring current and developing topics in sterol research together in Biochemistry and Function of Sterols. The authors are experts in each major area of sterol research-medicine, biochemistry, chemistry, and agriculture. Each chapter features the current state of research as well as new and developing research topics. Throughout the volume the focus is on the major and expanding areas of sterol biochemistry and function of sterols in all classes or organisms. The broad scope of this work embraces many disciplines and will be of interest to a variety of researchers, students, and lay people. Professors will find Biochemistry and Function of Sterols an excellent choice as a textbook for courses on steroid, lipid, or plant biochemistry.
Download or read book The Nature of Nutrition written by Stephen J. Simpson and published by Princeton University Press. This book was released on 2012-07-22 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nutrition has long been considered more the domain of medicine and agriculture than of the biological sciences, yet it touches and shapes all aspects of the natural world. The need for nutrients determines whether wild animals thrive, how populations evolve and decline, and how ecological communities are structured. 'The Nature of Nutrition' addresses nutrition's enormously complex role in biology, both at the level of individual organisms and in their broader ecological interactions.
Download or read book Cholesterol Systems in Insects and Animals written by Jacqueline Dupont and published by CRC Press. This book was released on 2018-05-04 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reviews in this collection are unique in their intent to provide a basis for understanding of the subject. They include historical, descriptive, and comparative information which is not always presented in state of the science reviews. Cholesterol is viewed in each chapter as part of a system structural, kinetic, or metabolic. The complex nature of the place of cholesterol in living systems is illustrated in each chapter.
Download or read book Regulation Digestion Nutrition Excretion written by G. A. Kerkut and published by Elsevier. This book was released on 2013-10-22 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this volume, seven of the chapters deal with feeding and diet, which is reasonable since insects consume an estimated l5-20% of all the world's planted crops. Many insects even have a specialized larval feeding stage that usually occupies a different ecological niche to the adult and so does not compete for the adult's food stock. Other chapters describe the means by which insects maintain their water balance, nitrogen balance and temperature balance under a range of conditions. These involve regulation by hormonal and behavioural systems that are also described here. The l4 chapters are all extensively illustrated and referenced and therefore provide excellent summaries of current knowledge. They will be of great value to entomologists, zoologists and biologists in general.
Download or read book Pesticides Documentation Bulletin written by and published by . This book was released on 1968 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Organization of Membranes Where Biology Meets Biophysics written by and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biological membranes protect cells and organelles from the surrounding environment, but serve also as organising platforms for physiological processes such as cell signalling. The hydrophobic core of membranes is composed of lipids and proteins influencing each other. Local membrane composition and properties define its molecular organisation and, in this way, regulate the function of all associated molecules. Therefore, studying interactions of components, biophysical properties and overall membrane dynamics provides essential information on its function in the context of cell activities. Such knowledge can contribute to biomedical fields such as pharmacology, immunology, neurobiology and many others. The goal of the Research Topic entitled 'Molecular organisation of membranes: where biology meets biophysics' was to provide a comprehensive platform for publishing articles, reviews and opinions focused on membrane organisation and the forces behind its heterogeneous and dynamic structure. We collected 11 works which cover topics as diverse as general membrane organisation models, membrane trafficking and signalling regulation, biogenesis of caveolae, protein-lipid interactions and the importance of membrane-associated tetraspanins networks. The prevalent theme was the existence of membrane nanodomains. To this point, new emerging technologies are presented which own the power to bring a novel insight on how membrane nanodomains are formed and maintained and what is their function. We believe that the collection of works in this Research Topic brings forward some important questions which will stimulate further research in this difficult but exciting field.
Download or read book Fundamentals of Microbiome Science written by Angela E. Douglas and published by Princeton University Press. This book was released on 2021-06-08 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book provides an accessible and authoritative guide to the fundamental principles of microbiome science, an exciting and fast-emerging new discipline that is reshaping many aspects of the life sciences. Resident microbes in healthy animals--including humans--can dictate many traits of the animal host. This animal microbiome is a second immune system conferring protection against pathogens; it can structure host metabolism in animals as diverse as reef corals and hibernating mammals; and it may influence animal behavior, from social recognition to emotional states. These microbial partners can also drive ecologically important traits, from thermal tolerance to diet, and have contributed to animal diversification over long evolutionary timescales"--Publisher by publisher.
Download or read book Introduction to Chemical Ecology written by Michel Barbier and published by Longman Publishing Group. This book was released on 1979 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Chemical ecology may be defined as the study of the chemical relationships that exist between living organisms, and between the living and non-living world. ...Michel Barbier [discusses] a wide spectrum of examples, including phytotoxins, mycotoxins, venoms, antibiotics and pheromones." From BACK COVER.
Download or read book Advances in Comparative Physiology and Biochemistry V8 written by O Lowenstein and published by Elsevier. This book was released on 2012-12-02 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Comparative Physiology and Biochemistry, Volume 8, presents five papers covering topics that range from biochemical aspects of the genetics of the various mutants of the fruit fly Drosophila to the physiological, biophysical, and biochemical mechanisms in diving animals. The first study on the biochemistry and genetics of purine metabolism in Drosophila melanogaster examines purine nucleotide biosynthesis and interconversion, catabolism of purines, genetics of catabolic enzymes, and purine auxotrophy. The second study on central nervous system regulation of pituitary melanocyte-stimulating hormone presents experiments with amphibians, reptiles, and mammals that test nervous-neuroendocrine control of MSS release. The third study examines the comparative physiology of calcium regulation in submammalian vertebrates, including fishes, amphibians, and birds. The fourth study looks at the cerebellum of fishes. The final paper deals with the comparative physiology of diving in vertebrates. The book will be useful to biologists given their appreciation of functional biological principles, as well as a reference tool for specialists.
Download or read book Serum Plasma Proteomics written by Richard J Simpson and published by Humana Press. This book was released on 2016-05-01 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Blood science has become a cornerstone of multiple disciplines. This book, contributed to by leading experts in the field, provides a comprehensive resource of protocols for areas, pre-analytical through to analytical, of plasma and serum proteomics.
Download or read book Insect Diapause written by David L. Denlinger and published by Cambridge University Press. This book was released on 2022-02-03 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our highly seasonal world restricts insect activity to brief portions of the year. This feature necessitates a sophisticated interpretation of seasonal changes and enactment of mechanisms for bringing development to a halt and then reinitiating it when the inimical season is past. The dormant state of diapause serves to bridge the unfavourable seasons, and its timing provides a powerful mechanism for synchronizing insect development. This book explores how seasonal signals are monitored and used by insects to enact specific molecular pathways that generate the diapause phenotype. The broad perspective offered here scales from the ecological to the molecular and thus provides a comprehensive view of this exciting and vibrant research field, offering insights on topics ranging from pest management, evolution, speciation, climate change and disease transmission, to human health, as well as analogies with other forms of invertebrate dormancy and mammalian hibernation.
Download or read book The Soviet Journal of Developmental Biology written by and published by . This book was released on 1989 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Drosophila written by Christian Dahmann and published by Humana. This book was released on 2016-10-12 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second edition volume expands on the previous edition by presenting updated protocols for several of the techniques described in the first edition of Drosophila: Methods and Protocols and current methods that cover recent breakthroughs in Drosophila research. The book begins with a description of FlyBase--a database of genes and genomes--followed by the presentation of systems for versatile gene expression in the fly. The first few chapters in this book detail gene knockdown and editing, including CRISPR-Cas9 and protein knockdown. The next few chapters are devoted to methods describing live imaging of different tissues and organs, followed by chapters on how to quantify image data and how to probe tissue mechanics by laser ablation. The next two chapters provide methods for analyzing transcription followed by protocols to study growth, metabolism, ageing, and behavior in Drosophila. This volume concludes with chapters on electrophysiological recordings and methods to establish cell lines. Written in the highly successful Methods in Molecular Biology series format, 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. Cutting-edge and thorough, Drosophila: Methods and Protocols, Second Edition is a valuable source of hands-on protocols and reviews for molecular, cell, and developmental biologists using Drosophila as model systems in their work.
