Download or read book Cis regulatory Mechanisms Regulating Gene Expression in C Elegans Chemosensory Neurons written by Eva B. Nokes and published by . This book was released on 2010 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neuronal Regulation of Chemosensory Signaling in Caenorhabditis Elegans written by Meredith Jean Ezak and published by . This book was released on 2011 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: All animals rely on their ability to sense and respond to their constantly changing environments to survive. Caenorhabditis elegans depend heavily upon their ability to taste and smell chemical information in their soil habitat to find favorable conditions and avoid noxious environments. While similar signal transduction pathways are implicated in both C. elegans and vertebrate chemosensation, there are still large gaps in our understanding of the mechanisms used to regulate signaling in these systems. I have sought to define cellular pathways that modulate signaling activity, and ultimately responsiveness, of chemosensory neurons in C. elegans. I describe herein the identification of cell- and modality-specific pathways that regulate neuronal activity in response to aberrant signaling, as well as a novel mechanism by which neuronal cells may regulate expression of sensory genes to directly impact cellular activity.
Download or read book Multiple Mechanisms Contribute to Regulation of Gene Expression in the C Elegans Excretory System written by Kristin R. Armstrong and published by . This book was released on 2008 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Gene regulation is controlled by multiple mechanisms that function at levels ranging from genome-wide to gene-specific. Understanding the mechanisms of gene regulation at all levels is important for discerning proper organ development and function as well as interpreting the changes that occur in mutant organs, which lead to defects and diseases. To better understand the mechanisms functioning at different levels of gene regulation in organ development and function, I studied the role of the environment, chromatin remodeling, and gene-specific transcriptional regulation on the C. elegans excretory system, which is similar to mammalian kidneys. Class III POU-homeobox transcription factors are expressed in the renal organs of species from C. elegans to mammals. However, the functional role for these factors in renal organs is not well characterized. In this dissertation, I studied the role of the C. elegans POU-III transcription factor, CEH-6, in the excretory cell to address this question. I performed molecular and biochemical studies, which show CEH-6 regulates a subset of genes expressed in the excretory cell. This work suggests that a role for POU-III factors in renal organs may be to modulate the expression of functionally related genes. Chromatin structure also influences the accessibility of transcription factors to target genes, and thereby is important for gene expression. In this study, I show LEX-1 and TAM-1 function to attenuate transgene silencing in somatic tissue by acting regionally as part of a complex that broadly regulates expression of genes in repetitive DNA. Additionally, environmental cues can play a role in regulating gene expression. Previous work by other labs has shown dauer larvae exhibit an increased osmotic tolerance, suggesting the excretory system may be altered. I was interested in understanding the biological changes responsible so I characterized the excretory system anatomy in dauer larvae. I found an altered morphology and the positional alignment of the excretory duct cell and excretory cell in dauer larvae, which may be related to the increased osmotic tolerance. Together, the results from these studies support the idea that organisms integrate information from multiple levels and mechanisms of regulation in order to direct their development and function.
Download or read book Regulatory Mechanisms of Chemosensory Signaling in Caenorhabditis Elegans written by Michelle Christine Krzyzanowski and published by . This book was released on 2015 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: All animals rely on their ability to sense and respond to their environment to survive. While similar signal transduction pathways are implicated in both C. elegans and vertebrate chemosensation, there are still large gaps in our understanding of the mechanisms used to regulate signaling in these systems. In my thesis, I have identified a new role for the C. elegans cGMP-dependent protein kinase (PKG) EGL-4 in the negative regulation of nociceptive chemosensory signaling. Nociceptive sensory systems detect harmful stimuli and allow for the initiation of protective behavioral responses. The polymodal ASH sensory neurons are the primary nociceptors in C. elegans. The data suggest that EGL-4 negatively regulates signaling and behavior by activating known inhibitors of G protein-coupled signal transduction, RGS proteins. Using C. elegans behavioral response to aversive stimuli as the readout for neuronal activity, I provide the first evidence for PKG regulation of RGS function in sensory neurons in any system. Additionally, the suitability of a behavioral response is context-dependent, and must reflect both an animal's life history and its present internal state. Based on the integration of these variables, an animal's needs can be prioritized to optimize survival strategies. I show that cGMP movement through a gap junction neural network allows dynamic repurposing of several C. elegans head sensory neurons to regulate ASH sensitivity through EGL-4 function in response to an animal's feeding status. Such decentralized regulation of ASH signaling allows for rapid correlation between an animal's internal state and its behavioral output, and lends an unexpected modulatory flexibility to this hard-wired nociceptive neural circuit.
Download or read book Dissection of Cis regulatory Sequences Regulating Sensory Gene Expression in Caenorhabditis Elegans written by Helen Yeung and published by . This book was released on 2005 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Regulation of Cell identity Maintenance in C Elegans written by Joshua Clayton Saul and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multicellular organisms are composed of a huge variety of different cell types, defined by their unique morphology, function, and gene expression. In animals, these characteristics are established during development, where internal and external cues guide the determination and differentiation of distinct cell identities. Following the establishment of a cell identity, that identity must be maintained for the remaining life of that cell. Maintenance requires both the continued expression of genes that define that terminally differentiated cell type, as well as suppression of the expression of genes that do not. Master transcriptional regulators are able to maintain the expression of genes in a terminally differentiated cell, though they can also drive the expression of additional undesired genes in a given cell type. The mechanisms by which the expression of these undesired genes is suppressed are poorly understood. In this dissertation, I describe genetic analyses of the nematode C. elegans that have provided insights into a mechanism that cells utilize to regulate gene expression and in turn maintain the identities of terminally differentiated cell types.
Download or read book The Neurobiology of Olfaction written by Anna Menini and published by CRC Press. This book was released on 2009-11-24 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Overview of Advances in OlfactionThe common belief is that human smell perception is much reduced compared with other mammals, so that whatever abilities are uncovered and investigated in animal research would have little significance for humans. However, new evidence from a variety of sources indicates this traditional view is likely
Download or read book Mechanisms by which Feeding State and Sex are Integrated to Regulate Chemosensory Plasticity in C Elegans written by Leigh R. Wexler and published by . This book was released on 2019 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: The feeding-state of an animal can have deep effects on its chemosensation and behavioral decisions. Although many internal signals of nutritional state and hunger are known, the mechanisms by which these modulate neural circuits and behavior are less well understood. C. elegans display an interesting intersection of feeding state and sex in the regulation of chemosensory behavior. Self-fertile hermaphrodites exhibit strong food attraction while males prioritize mate-searching over feeding. This sexual dimorphism is regulated in part through differences the chemoreceptor ODR-10, which detects the food-associated odorant diacetyl in the AWA neuron. Hermaphrodites expresses high levels of odr-10 while in adult males, expression of odr-10 is low, promoting exploratory behavior. However, starved males transiently upregulate odr-10 to generate stronger food attraction until their nutritional needs are met. This multi-layered regulation of odr-10 provides an opportunity to study how neural circuits integrate genetic sex and feeding-state to regulate chemosensory behaviors through chemoreceptor expression. We show that in response to food availability, odr-10 is modulated in males through insulin-like signaling and DAF-7/TGF? signaling. Interestingly, we find that in males odr-10 is regulated primarily by sensory perception of food, not metabolic starvation. Similarly, the TGF? ligand daf-7 is regulated in the ASJ neuron by food perception, linking environmental signals to odr-10. Additionally, these mechanisms are modulated by sex. We show hermaphrodites also regulate odr-10 in response to feeding state, however they do so through divergent mechanisms from males, independent of insulin and TFG? signaling and in response to metabolic starvation. Through this work we identify a male-specific mechanisms which modulates chemosensation based on environmental conditions furthering our understanding of how chemoreceptor expression and behavioral choice is regulated through multiple internal and external states.
Download or read book Transcriptional Regulation of C Elegans Excretory Cell expressed Genes by the POU Homeobox Transcription Factor CEH 6 written by Allan Mah and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Caenorhabditis elegans' excretory cell is a large cell that extends the entire length of the nematode and is functionally analogous to a kidney. In order to develop a better understanding of genes involved in the development of the excretory cell, I have characterized a transcriptional regulatory mechanism involved in driving gene expression in this cell. Seven of the 13 vertebrate Aquaporins (AQPs; water channel proteins) express in the kidney where they assist in recapturing water lost because of renal filtration. There are also 12 aqp-encoding genes in C. elegans of which three express in the excretory cell. The expression pattern of aqp-8 is limited to the excretory cell during post-embryonic developmental stages based on a GFP tagging assay. Analysis of 5' truncations of aqp-8's promoter region, coupled with interspecies comparative analyses, revealed that an octamer DNA element (ATTTGCAT) is critical for driving excretory cell expression. The octamer element associates with POU homeobox proteins of which there are three in C. elegans. The class III POU transcription factor homolog, ceh-6, is an essential gene and is the only POU member with an expression pattern that overlaps with aqp-8's. I have demonstrated, using both in vitro and in vivo approaches, that CEH-6 is the cognate transcription factor for the octamer motif. I have searched the genome for genes controlled by this transcriptional regulatory mechanism by locating interspecies conserved octamer motifs in gene-upstream regions. The candidate promoter regions were tested for their ability to drive expression in the excretory cell. I assessed the dependence on the cis-regulatory element for driving excretory cell expression by assessing the expression patterns of 5' promoter truncation constructs targeting the octamer motif. I have identified nine genes that are modulated by the CEH-6/octamer motif regulatory mechanism including the five: M176.5 (a gene of unknown function), sdr-2 (a ferric reductase), F16F9.1 (a transcription factor), twk-36 (a potassium channel), and R02F2.8 (an amino acid transporter).
Download or read book Genomic Regulatory Systems written by Eric H. Davidson and published by Elsevier. This book was released on 2001-01-24 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction between biology and evolution has been the subject of great interest in recent years. Because evolution is such a highly debated topic, a biologically oriented discussion will appeal not only to scientists and biologists but also to the interested lay person. This topic will always be a subject of controversy and therefore any breaking information regarding it is of great interest.The author is a recognized expert in the field of developmental biology and has been instrumental in elucidating the relationship between biology and evolution. The study of evolution is of interest to many different kinds of people and Genomic Regulatory Systems: In Development and Evolution is written at a level that is very easy to read and understand even for the nonscientist. * Contents Include* Regulatory Hardwiring: A Brief Overview of the Genomic Control Apparatus and Its Causal Role in Development and Evolution * Inside the Cis-Regulatory Module: Control Logic and How the Regulatory Environment Is Transduced into Spatial Patterns of Gene Expression* Regulation of Direct Cell-Type Specification in Early Development* The Secret of the Bilaterians: Abstract Regulatory Design in Building Adult Body Parts* Changes That Make New Forms: Gene Regulatory Systems and the Evolution of Body Plans
Download or read book C Elegans II written by Donald L. Riddle and published by Firefly Books. This book was released on 1997 with total page 1252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Defines the current status of research in the genetics, anatomy, and development of the nematode C. elegans, providing a detailed molecular explanation of how development is regulated and how the nervous system specifies varied aspects of behavior. Contains sections on the genome, development, neural networks and behavior, and life history and evolution. Appendices offer genetic nomenclature, a list of laboratory strain and allele designations, skeleton genetic maps, a list of characterized genes, a table of neurotransmitter assignments for specific neurons, and information on codon usage. Includes bandw photos. For researchers in worm studies, as well as the wider community of researchers in cell and molecular biology. Annotation copyrighted by Book News, Inc., Portland, OR
Download or read book MicroRNAs written by Krishnarao Appasani and published by Cambridge University Press. This book was released on 2009-08-20 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: MicroRNAs (miRNAs) are RNA molecules, conserved by evolution, that regulate gene expressions and their recent discovery is revolutionising both basic biomedical research and drug discovery. Expression levels of MiRNAs have been found to vary between tissues and with developmental stages and hence evaluation of the global expression of miRNAs potentially provides opportunities to identify regulatory points for many different biological processes. This wide-ranging reference work, written by leading experts from both academia and industry, will be an invaluable resource for all those wishing to use miRNA techniques in their own research, from graduate students, post-docs and researchers in academia to those working in R&D in biotechnology and pharmaceutical companies who need to understand this emerging technology. From the discovery of miRNAs and their functions to their detection and role in disease biology, this volume uniquely integrates the basic science with industry application towards drug validation, diagnostic and therapeutic development. Forewords by: Sidney Altman, Yale University, Winner of the Nobel Prize in Chemistry, 1989 and Victor R. Ambros, Dartmouth Medical School, Co-discoverer of MicroRNAs
Download or read book A Genetic Switch written by Mark Ptashne and published by CSHL Press. This book was released on 2004 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first edition of Mark Ptashne's 1986 book describing the principles of gene regulation in phage lambda became a classic in both content and form, setting a standard of clarity and precise prose that has rarely been bettered. This newly updated third edition focuses once again solely on phage, incorporating the most recent insights into gene expression in prokaryotes while retaining all the special qualities of the original edition
Download or read book Mechanisms of Life History Evolution written by Thomas Flatt and published by OUP Oxford. This book was released on 2011-05-12 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: Life history theory seeks to explain the evolution of the major features of life cycles by analyzing the ecological factors that shape age-specific schedules of growth, reproduction, and survival and by investigating the trade-offs that constrain the evolution of these traits. Although life history theory has made enormous progress in explaining the diversity of life history strategies among species, it traditionally ignores the underlying proximate mechanisms. This novel book argues that many fundamental problems in life history evolution, including the nature of trade-offs, can only be fully resolved if we begin to integrate information on developmental, physiological, and genetic mechanisms into the classical life history framework. Each chapter is written by an established or up-and-coming leader in their respective field; they not only represent the state of the art but also offer fresh perspectives for future research. The text is divided into 7 sections that cover basic concepts (Part 1), the mechanisms that affect different parts of the life cycle (growth, development, and maturation; reproduction; and aging and somatic maintenance) (Parts 2-4), life history plasticity (Part 5), life history integration and trade-offs (Part 6), and concludes with a synthesis chapter written by a prominent leader in the field and an editorial postscript (Part 7).
Download or read book The Mouse Nervous System written by Charles Watson and published by Academic Press. This book was released on 2011-11-28 with total page 815 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mouse Nervous System provides a comprehensive account of the central nervous system of the mouse. The book is aimed at molecular biologists who need a book that introduces them to the anatomy of the mouse brain and spinal cord, but also takes them into the relevant details of development and organization of the area they have chosen to study. The Mouse Nervous System offers a wealth of new information for experienced anatomists who work on mice. The book serves as a valuable resource for researchers and graduate students in neuroscience. Systematic consideration of the anatomy and connections of all regions of the brain and spinal cord by the authors of the most cited rodent brain atlases A major section (12 chapters) on functional systems related to motor control, sensation, and behavioral and emotional states A detailed analysis of gene expression during development of the forebrain by Luis Puelles, the leading researcher in this area Full coverage of the role of gene expression during development and the new field of genetic neuroanatomy using site-specific recombinases Examples of the use of mouse models in the study of neurological illness
Download or read book Animal Anomalies written by Lewis I. Held, Jr and published by Cambridge University Press. This book was released on 2021-03-18 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highlights what we know about the pathways pursued by embryos and evolution, and stresses what we do not yet know.
Download or read book Nematode Trapping Fungi written by Ke-Qin Zhang and published by Springer Science & Business. This book was released on 2014-04-22 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: These chapters provide up-to-date information on nematophagous fungi, particularly those of the Orbiliaceae in Ascomycota, whose asexual states produce nematode-trapping devices. The authors consider fungal-nematode interactions, fossil fungi, the biodiversity, ecology and geographical distribution of nematode-trapping fungi, and their potential use in biocontrol of nematodes, all in detail. Nematode-trapping fungi with adhesive or mechanical hyphal traps are the main focus of this book which begins with an overview of the data on nematode-trapping fungi, including their taxonomy, phylogeny and evolution. Subsequent chapters expand upon the methods and techniques used to study these fascinating fungi. Keys for genera of Arthrobotrys, Drechslerella and Dactylellina, which include all reported species of predatory orbiliaceous fungi are presented and numerous species from these genera are morphologically described and illustrated. The ecology of nematode-trapping fungi is expertly presented: their occurrence and habitats, their geographical and seasonal distribution and the effects of soil conditions and nematode density on their distribution all feature amongst the relevant themes. Further chapters examine the use of nematode-trapping fungi in biological control and the authors consider nematicidal activities in detail, exploring the many compounds from fungi that feature in nematicidal activities and of course useful paths for further study on this topic. This is a highly informative and carefully presented book, providing scientific insight for scholars with an interest in fungi and in biological control of nematodes.
