Download or read book Proteomic Analysis of Oyster Larvae Reveals Molecular Mechanism of Ocean Acidification and Multiple Stressor Effects written by Dineshram Ramadoss and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Proteomic Analysis of Oyster Larvae Reveals Molecular Mechanism of Ocean Acidification and Multiple Stressor Effects" by Dineshram, Ramadoss, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The increase in carbon dioxide emissions due to human activities has led to drastic variations in global climate. In addition to global warming and extreme weather patterns, the high CO2 levels have been leading to progressive ocean acidification. Compounded with other climate change related stressors, ocean acidification will hinder the ability of marine organisms to adapt to the ensuing changes and might affect human dependence on oceans as a source of food. Most marine organisms have complex life cycles, involving metamorphosis from larval to adult forms. In the early stages of life, oysters have calcium carbonate shells that are particularly sensitive to low pH, and the rapid climatic changes can compromise their metamorphosis. High temperature, low salinity and low pH resulting from ocean acidification are detrimental to both native and cultivated oyster populations. Although mechanistic studies to understand the tolerance responses of closely related species would be significant in this context, none have been reported to date. Therefore, this thesis aims to reveal the mechanisms that distinguish the "winners" from the "losers" among the selected aquatic species of commercial importance, in withstanding the stress induced by climate change. The present study employed molecular approaches to evaluate the interactive and cumulative effects of multiple stressors on large-scale cultures of pediveliger larvae from two oyster populations, Crassostrea hongkongensis and Crassostrea gigas. The study undertook transcriptomic and proteomic profiling of changes induced by ocean acidification in the larvae. The results revealed that oyster larvae could adopt an energy 'trade-off' strategy through metabolic suppression and adjust cell signalling pathways to overcome the stress induced by ocean acidification. Information from the oyster genome database facilitated the shotgun proteomics investigations on oyster larvae remarkably revealed over 1350 proteins in both the species. The study identified species- and stressor-specific tolerance responses, and survival mechanisms that preserved calcification, in oyster larvae. The larvae showed depletion of energy reserves due to enhanced metabolism, oxidative damage-induced immune response and metabolic suppression. The study reveals the existence of tolerance mechanisms in oysters that help them adapt to stresses resulting from climate change. It pioneered the use of a proteomics approach to understand the impact of multiple stressors on oyster larvae and the molecular mechanisms underlying their successful adaptation to them. Highlighted several potential possible biomarkers in this study will likely to play an important role in identifying oyster species showing heritable tolerance for future aquaculture. DOI: 10.5353/th_b5317012 Subjects: Ocean acidification Oysters - Effect of stress on

Download or read book Proteomic Analysis of Oyster Larvae Reveals Molecular Mechanism of Ocean Acidification and Multiple Stressor Effects written by Dineshram Ramadoss and published by . This book was released on 2014 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Ocean Acidification on Multiple Life History Stages of the Pacific Oyster Crassostrea Gigas written by Emma B. Timmins-Schiffman and published by . This book was released on 2014 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: As global climate change accelerates, due in large part to increasing emissions of carbon dioxide and other greenhouse gases from fossil fuel use, agriculture, and large-scale changes in land use, natural ecosystems bear the consequences. For marine systems these include increased mean seawater temperature, changes in carbonate chemistry equilibria, and increased pollutant loading due to non-point run-off, among other effects. Human-induced environmental changes will not have the same magnitude of effect in all regions, but on average the changes occurring are rapid and significant. Natural populations will either need to acclimatize and/or adapt, or shift their ranges to enable continued existence. This dissertation explores the effects of ocean acidification on the Pacific oyster, Crassostrea gigas. Oysters are sedentary and inhabit a naturally variable environment (the intertidal zone) and thus may be pre-adapted to withstand rapid environmental change. Oysters and similarly sedentary organisms are ideal for investigating the effects of environmental change on biology because they are not able to escape these changes, but must respond physiologically (acclimatize) if they are to survive. Due to this ecological history, oysters provide a model that allows us to explore potential physiological mechanisms that are needed in a response to specific environmental changes as well as the limits of these mechanisms. In the first chapter, the effects of elevated partial pressure of CO2 (pCO2, a major driver of ocean acidification) on oyster larvae are explored. Larvae were exposed to low pH during early development, a period that included the transition from energetic dependence on maternally derived lipids to dependence on exogenous resources. Larvae were found to experience a developmental delay at elevated pCO2, manifested as smaller size and slower rate of shell deposition. These significant effects of ocean acidification on early larval development may indicate a bottleneck in the oyster life cycle as the pH of marine waters decreases. Subsequent research has shown that these effects at early larval stages can carry over into later stages after settlement in another oyster species (Hettinger et al. 2012). In order to better understand the effects of environmental change on oyster physiology, we developed proteomic tools to explore changes in protein pathways in oyster gill (ctenidia) tissue. The second chapter explores the gill proteome (suite of expressed proteins) of adult oysters. Characterization of the proteome provides insight into the physiological mechanisms that may be available to the oyster during response to an environmental stress. The results revealed that the ctenidia proteome includes a diverse array of proteins that accomplish many functions and that it is a metabolically active tissue. The proteome sequencing lays the groundwork for exploring how ocean acidification affects various proteomic pathways in the tissue that acts as the interface between the oyster and its environment. Lastly, the adult oyster response to ocean acidification and a second stress are explored via proteomics, fatty acid profiles, glycogen content, shell microstructure, and mortality in response to heat shock. There was a significant impact of ocean acidification on oyster shell integrity, but no effects after one month of exposure on relative amounts of fatty acid, glycogen or response to acute heat shock. Through the proteomic analysis, we revealed an active and significant proteomic response to ocean acidification exposure, uncovering some of the mechanisms behind the observed macro-phenotypic changes. Additionally, the proteomic response to mechanical stimulation was largely altered between low and high pCO2, suggesting that ocean acidification can fundamentally change how oysters respond to a second stress.

Download or read book Ocean Acidification Influences on Physiology and Epigenetics in the Pacific Oyster Crassostrea Gigas written by Yaamini Ranjani Venkataraman and published by . This book was released on 2021 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: As ocean acidification continues to impact marine ecosystems at unprecedented rates, phenotypicplasticity may allow organisms to withstand more stressful conditions. Genomic methods can elucidate molecular mechanisms that contribute to phenotypic plasticity, allowing for a deeper understanding of how physiological processes will be impacted by low pH. My dissertation examines the effects of ocean acidification on the Pacific oyster (Crassostrea gigas) stress response and reproduction; elucidate how exposure history impacts phenotype; and explore the role of functional role DNA methylation in somatic and reproductive tissue. I investigated the effect of regional environmental variation on the molecular physiology of C. gigas outplanted at five different estuarine sites (four in Puget Sound, one in Willapa Bay) in Washington, USA using gel-free proteomic methods. While there was no difference in survival, or any protein abundances due to pH differences between sites, C. gigas outplanted at the site with the highest temperature had significantly higher abundances of antioxidant enzymes and molecular chaperones, elucidating the molecular underpinnings of thermotolerance. In a hatchery setting, I explored the impact of ocean acidification on reproductive maturity and output. A seven week low pH exposure did not affect sex ratio or maturation stage; however, it did significantly affect survival of larvae. Even though adult oysters spent four months in ambient pH conditions between low pH exposure and strip spawning, larvae from females that experienced low pH conditions had significantly higher mortality. Finally, I conducted the first investigations examining the effect of ocean acidification in C. gigas methylomes. To investigate the role of environmentally-responsive methylation in reproductive tissue, I analyzed gonad methylomes of female C. gigas exposed to low pH. A total of 1,599 differentially methylated loci (DML) were found in gene bodies. The genic DML were associated with cilium movement, development, and cytoskeletal processes, implying a need to regulate cellular growth in the gonad in response to low pH. I then explored the influence of low pH on the somatic tissue methylome using diploid and triploid oyster ctenidia. Differences in ploidy status yielded 154 DML. These ploidy-DML were associated with cell-cell adhesion and dephosphorlylation processes, which are not commonly associated with methylome changes in organisms that undergo natural polyploidization. The 178 pH-DML were associated with processes commonly observed in oysters exposed to ocean acidification, including apoptosis, protein ubiquitination, zinc ion binding, and cytoskeletal processes. In both reproductive and somatic tissue, the enrichment of DML in genes with multiple transcripts could indicate a role for methylation to regulate gene expression via alternative splicing. Investigating the molecular underpinnings of responses to ocean acidification in C. gigas will provide a thorough understanding of this global aquaculture product’s ability to withstand future ocean conditions.

Download or read book Ecophysiology and Ocean Acidification in Marine Mollusks written by Youji Wang and published by Elsevier. This book was released on 2024-08-23 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ecophysiology and Ocean Acidification in Marine Mollusks: From Molecule to Behavior provides an extensive overview of the latest research on the various ecophysiological effects of ocean acidification on marine mollusks. This book synthesizes historical information and recent findings on the effects of environmental change, ocean warming, and acidification on key mollusks and their life-history. It also discusses the underlying mechanisms underpinning the effects of ocean warming and acidification. Written by internationally recognized experts in the field of marine biology, this book systematically examines the effects of ocean acidification on the reproduction, growth and development, physiological metabolism, immunity, and behavior of marine mollusks. The book concludes by discussing the implications of current research, acknowledging data limitations in the field, and proposing future research directions, providing a better understanding of the potential impacts of ocean acidification on mollusks and the global aquaculture industry and inspiring new thinking for future research practices. It will be an indispensable resource for researchers, practitioners, undergraduate and graduate students, conservationists, and aquaculturists alike who are interested in marine environmental change, ecology, physiology, and marine biology. Describes the causes and consequences of ocean acidification in the marine environment Summarizes our modern understanding of the impact of ocean acidification on the physiology and behavior of marine mollusks Discusses the limitations of existing studies Proposes future research directions on ocean acidification and marine mollusks

Download or read book Intracellular Basis of Climate Change Resilience in Oysters written by Priscila Gonçalves and published by . This book was released on 2016 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change is making the world's oceans warmer and more acidic. This environmental disturbance represents a major threat to marine life, particularly to calcifying organisms, such as oysters. Although adaptation to climate change is possible for many marine species, the intracellular basis of such stress-induced modifications is largely unknown. This thesis aims to discover the biological mechanisms that provide heritable protection against the adverse effects of climate change stressors in oysters. I explore the molecular processes underlying the improved performance of selectively bred populations of Sydney rock oysters (Saccostrea glomerata) under acidifying conditions. The thesis assesses the intracellular responses of CO2-resilient and wild type (non-selected) oysters following single or transgenerational exposures to elevated CO2 using transcriptomics, proteomics and cytology. The molecular profiles of CO2-resilient oysters were also investigated in response to a combination of CO2 and thermal stresses. It was found that elevated CO2 affected different levels of biological complexity,ranging from changes in cellular structures (mitochondria and associated systems) to alterations in protein concentrations and gene expression. The data showed that oysters are highly responsive to ocean acidification, and that discrete populations of oysters differ in their responsiveness. CO2-resilient oysters exhibited differential regulation of genes and proteins involved in a variety of fundamental cellular processes, including control of the cell cycle, maintenance of cellular homeostasis, energy metabolism and stress responses. Transgenerational exposures to elevated CO2 further altered the transcriptional profiles of oyster populations, suggesting that they may also be able to undergo rapid acclimation or adaptation to CO2 at the transcriptional level. However, concurrent exposure to CO2 and thermal stresses did not produce additive or synergistic effects on the molecular responses of CO2-resilient oysters. This indicates that the inherent capacity of selectively bred oysters to better cope with CO2 stress may not extend to ocean warming, or that the addition of thermal stress overwhelms oyster stress responses. Overall, the thesis reveals the molecular processes that may enable marine organisms to survive and thrive as climate change progresses. I conclude by considering the implications of this knowledge to ecosystem dynamics and fisheries production, highlighting potential strategies to minimise the impacts of this imminent threat.

Download or read book Consequences of Global Change for Early Life Stages of the Olympia Oyster written by Annaliese Hettinger and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The nearshore marine environment is characterized by a multitude of natural and human-induced stressors. The interactive effects of stressors may complicate predicting ecological effects of global change on marine organisms. This dissertation focuses primarily on how altered seawater chemistry (ocean acidification), derived from increased atmospheric carbon dioxide, interacts with other environmental factors to influence the early life stages of Olympia oysters (Ostrea lurida). Initial laboratory experiments demonstrated that exposure of oyster larvae to high-CO2 caused lower growth rates and smaller size at settlement compared to individuals reared in ambient-CO2. Impacts were more pronounced a week after settlement, with juveniles exhibiting a larger decrease in shell growth rate compared to the negative effect on larval growth rate. The effects on juveniles arose regardless of the CO2 level oysters experienced as juveniles, indicating a strong carry-over effect from the larval phase. A combined laboratory and field approach addressed the duration of carry-over effects and how effects might be moderated in the natural environment. Juvenile oysters reared in laboratory cultures under ambient and high-CO2 as larvae were outplanted to field sites at two intertidal shore levels that differed in emersion time and temperature regime. Larval exposure to high-CO2 led to reduced growth in juveniles. Juveniles outplanted to the more stressful shore level also exhibited reduced growth compared to individuals in more benign conditions. Effects persisted halfway to reproductive age, the duration of the study. To determine if the negative effects from ocean acidification would be exacerbated or ameliorated in a low or high food environment, respectively, oyster larvae were reared at two CO2 and three food levels. Larval growth was reduced in low food and in elevated-CO2 conditions, but these factors operated additively, indicating that the effects of high-CO2 on growth did not depend on the food regime. Settlement was lower in elevated-CO2 conditions compared to ambient, and this was especially true in low food conditions. High food levels did not completely eliminate negative effects of high-CO2 on growth. A final experiment demonstrated that moderate temperature increases buffered larval and juvenile oysters from the damaging effects of high-CO2. Ocean acidification negatively impacts multiple early life history stages of Olympia oysters, and may contribute to substantial declines at the population scale. Responses are not uniform across the life cycle, and thus assessments of population responses to environmental perturbation must consider how effects propagate across life-history transitions.

Download or read book Guide to Best Practices for Ocean Acidification Research and Data Reporting written by and published by . This book was released on 2011 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Molecular Physiology in Molluscs of Economic or Ecological Importance written by Xiaotong Wang and published by Frontiers Media SA. This book was released on 2019-10-24 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the largest marine phylum, molluscs comprise ~23% of all named marine organisms. Many molluscs have economic or ecological importance. With the development of molecular biology and omics techniques, significant gains have been made for molecular physiology in molluscs of economic or ecological importance.

Download or read book Marine Environmental Epigenetics written by Jose M. Eirin-Lopez and published by Frontiers Media SA. This book was released on 2021-07-05 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biomineralization Mechanism of the Pearl Oyster Pinctada fucata written by Rongqing Zhang and published by Springer. This book was released on 2019-01-04 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an overview of our current understanding of the biomineralization mechanisms for shell formation in the pearl oyster Pinctada fucata, based on molecular biology, biochemistry, cell biology, structural biology and environmental biology. Pinctada fucata is the major pearl-producing shellfish in the South China Sea and is also an established model system for the research on the nacre biomineralization mechanism. Extensive studies on nacre biomineralization have provided valuable information for novel bionic material design. Discussing the isolation and gene cloning of the matrix proteins involved in the shell formation, as well as the cell signaling pathways, shell microstructures, and the environmental impacts on shell biomineralization, it is a valuable reference resource for researchers working in the field of nacre biomineralization and biomaterials.

Download or read book Ocean Acidification written by National Research Council and published by National Academies Press. This book was released on 2010-09-14 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ocean has absorbed a significant portion of all human-made carbon dioxide emissions. This benefits human society by moderating the rate of climate change, but also causes unprecedented changes to ocean chemistry. Carbon dioxide taken up by the ocean decreases the pH of the water and leads to a suite of chemical changes collectively known as ocean acidification. The long term consequences of ocean acidification are not known, but are expected to result in changes to many ecosystems and the services they provide to society. Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean reviews the current state of knowledge, explores gaps in understanding, and identifies several key findings. Like climate change, ocean acidification is a growing global problem that will intensify with continued CO2 emissions and has the potential to change marine ecosystems and affect benefits to society. The federal government has taken positive initial steps by developing a national ocean acidification program, but more information is needed to fully understand and address the threat that ocean acidification may pose to marine ecosystems and the services they provide. In addition, a global observation network of chemical and biological sensors is needed to monitor changes in ocean conditions attributable to acidification.

Download or read book The Eastern Oyster written by Victor S. Kennedy and published by University of Maryland Sea Grant Publications. This book was released on 1996 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1966 Congress passed the National Sea Grant College Program Act to promote marine research, education, and extension services in institutions along the nation's ocean and Great Lakes coasts. In Maryland a Sea Grant Program -- a partnership among federal and state governments, universities, and industries -- began in 1977, and in 1982 the University of Maryland was named the nation's seventeenth Sea Grant College. The Maryland Sea Grant College focuses its efforts on the Chesapeake Bay, with emphasis on the marine concerns of fisheries, seafood technology, and environmental quality. The first comprehensive review of the biology of the eastern oyster in more than thirty years. The twenty-one chapters synthesize every aspect of oyster biology -- for instance, general anatomy, physiology, the circulatory system, reproduction, genetics, diseases -- and issues related to management and aquaculture.

Download or read book Mixture Toxicity written by Cornelis A. M. van Gestel and published by CRC Press. This book was released on 2016-04-19 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last decade and a half, great progress has been made in the development of concepts and models for mixture toxicity, both in human and environmental toxicology. However, due to their different protection goals, developments have often progressed in parallel but with little integration. Arguably the first book to clearly link ecotoxicology an

Download or read book Echinoderm Nutrition written by Michel Jangoux and published by CRC Press. This book was released on 1982-06-01 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to present the state of knowledge concerning nutrition and point out directions for future work for the Echinodermata, an ancient group which shows great diversity in form and function, and whose feeding activities can have great environmental impact.

Download or read book Hatchery Culture of Bivalves written by Michael M. Helm and published by Food & Agriculture Organization of the UN (FAO). This book was released on 2004 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: This manual is a synthesis of current methodologies pertinent to the intensive hatchery culture of bivalve molluscs. It encompasses both the similarities and differences in approach in rearing clams, oysters and scallops in different climatic zones. All aspects of the culture process are described, together with basic considerations in choosing a site for hatchery development and in the design of a suitable facility. It also includes the post-hatchery handling of larvae in remote setting and also of spat in both land- and sea-based nurseries. This document is intended to assist both technicians entering the field as well as entrepreneurs researching investment opportunities in bivalve culture.

Download or read book Echinoderm Larvae written by Herbert Clifton Chadwick and published by . This book was released on 1914 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: