Download or read book Identification of Novel RNAi Deficient Genes in C Elegans written by Chun-Chieh G. Chen and published by . This book was released on 2006 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book RNAi Suppressor Screen to Identify Novel Genetic Interactors with the Sydn 1 pfs 2 Neurodevelopmental Pathway of Caenorhabditis Elegans and Construction of Plasmid Vectors for Yeast two hybrid and in Vivo Analyses written by Mitchell Lee and published by . This book was released on 2012 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Identification of Axon Guidance Molecules by Genome wide RNAi Screen in C Elegans written by Fei Xie and published by . This book was released on 2007 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Identification of Novel Heterochronic Genes in the Nematode Caenorhabditis Elegans written by Juan E. Abrahante Lloréns and published by . This book was released on 2001 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Identification and Characterization of C Elegans RNAi Inheritance Machinery written by George Frederick Spracklin IV and published by . This book was released on 2016 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Small RNAs can regulate gene expression in eukaryotes. During RNA interference (RNAi), small RNAs are bound by Argonaute proteins and act as guide molecules to silence cellular RNAs. In C. elegans, RNAi silencing can persist for 6-10 generations in the absence of the initial trigger (termed RNAi inheritance). RNAi inheritance requires the nuclear RNAi factors NRDE-1/-2/-4 highlighting the importance of co-transcriptional gene silencing and heterochromatin formation in heritable gene silencing by dsRNA. This thesis explores how gene silencing propagates across generations by identifying and characterizing cellular factors required for RNAi inheritance in the model organism C. elegans. Chapter 2 of this thesis identifies six novel components of the RNAi inheritance machinery whose sequence conservation provides insights into the molecular mechanism of RNAi inheritance and strengthens the correlation between RNAi inheritance and germline immortality. Chapter 2 also demonstrates that HRDE-2 promotes RNAi inheritance by coupling the inheritance Ago HRDE-1 with the small RNAs it needs to direct RNAi inheritance and germline immortality.
Download or read book C elegans written by Ian A. Hope and published by OUP Oxford. This book was released on 1999-12-09 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Caenorhabditis Elegans has been a popular model organism for biological research for over thirty years and has been used to investigate many aspects of animal development, for example apoptosis, the Hox genes, signal transduction pathways, and the development of the nervous system. It has recently taken on new importance with the publication of the entire genome sequence in 1998. The first chapter gives all the basic information on C. elegans required to use it: it's natural history, anatomy, life cycle, development, and evolution. Information on how to obtain, grow, and maintain C. elegans for use as a model system is given in Chapter 4. Chapters 2 and 3 describe the genome project and show how to use genome sequence information by searching the database for homologues using different search methods and then how to analyse the search data. The next chapter gives the essential practical details of transformation and common uses for the technique. Chapter 6 covers reverse genetics and describes strategies for gene inactivation that are known to work in C elegans: epigenetic inactivation and mutational germ line inactivation. Chapter 7 is designed to help the user analyse phenotype by microscopy and includes Normaski, fluorescence, 4-dimensional, and electron microscopy. Techniques for studying the neurobiology of C. elegans are given in chapter 8. Chapter 9 describes the three commonly used approaches for studying gene expression and Chapter 10 deals with the common methods of molecular biology essential for gene characterization. C. elegans is not the ideal organism for biochemical studies, but chapter 11 describes several procedures for producing biochemically useful quantities of pure tissues. The final chapter is about conventional genetics and details the standard procedures for selfing and crossing; mutagenesis and mutant screening; characterization of mutants; gene mapping; temperature-shift experiments and mosaic analysis. Caenorhabditis Elegans: A Practical Approach will therefore provide all the background information necessary for use of C. elegans as a model system.
Download or read book Genetic Regulation of RNAi Inheritance in the C Elegans Germ Line written by and published by . This book was released on 2013 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: Small RNAs can regulate the expression of other cellular RNAs. RNA interference is a process by which small RNAs `silence' genes by inhibiting transcription or degrading messenger RNAs, preventing the gene from making functional products. RNAi induced silencing is epigenetic, the DNA sequence is left unaltered. Interestingly, RNAi induced silencing can be heritable for multiple generations. The nematode C. elegans is the perfect model for studying this epigenetic phenomenon C. elegans are amenable to RNAi and RNAi induced silencing of genes in the germ line can be heritable for many (>10) generations. This thesis aims to better understand the mechanism and genetics of RNAi inheritance in the C. elegans germ line. Chapter 2 of this thesis presents the identification of a novel nuclear Ago that promotes germline RNAi inheritance. Chapter 2 also highlights the importance of nuclear silencing in multigenerational RNAi inheritance and suggests that heterochromatin and siRNAs might act as heritable agents of RNAi memory. RNAi inheritance does not last forever. Chapter 3 explores the idea that the reason RNAi inheritance does not last forever might be because it is under negative regulation. Chapter 3 presents preliminary results from a forward genetic screen that was conducted to identify mutants in which RNAi inheritance is no longer limited and RNAi silencing can essentially become permanent.
Download or read book Large Scale RNAi Screen to Identify Genes Involved in Axon Guidance in Caenorhabditis Elegans written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was undertaken to identify genes involved in axon guidance in the nervous system of Caenorabditis elegans. Due to its unique physiological properties, the nematode worm C. elegans is a powerful genetic model system to study a variety of biological processes. The nervous system of C. elegans is a simple organ comprising 302 neurons. These neurons create stereotypic neuronal networks formed by their anterior-posterior and dorsal-ventral running axons. Here, we took advantage of the recently discovered phenomenon of RNA interference in the worm to identify axon guidance genes. However, the nervous system of C. elegans is refractory to the systemic RNA interference, and delivery of dsRNA molecules to the neighboring non-neuronal cells does not initiate RNAi in the neurons of the worm. Therefore, we started with the identification of mutants of C. elegans that are efficient for RNAi in the nervous system. A standard chemical mutagenesis screen was performed to identify mutants of the worm that showed enhanced RNAi efficiency in the nervous system. One of the mutants (nre-1, for neuronal RNAi efficient) showed marked suppression of gene expression in the nervous system by feeding RNAi approach. We used the nre-1 supersensitive strain as a tool in a reverse genetic screen to identify genes required for axon guidance in C. elegans. A transgenic strain was constructed in the nre-1 background, wherein a subset of interneurons and motor neurons were labeled with the yellow fluorescent protein to visualize axons of the neurons. We used this strain to screen 2416 gene of the worm located on chromosome I by feeding a library of bacterial clones expressing dsRNA fragments specific to the genes. This screen has identified 57 candidate genes that give rise to penetrant axon guidance defects in the commissural and ventral nerve cord axons in C. elegans. The genes identified include genes involved in various cellular processes such as DNA metabolism, translation, transcript.
Download or read book Methods of Behavior Analysis in Neuroscience written by Jerry J. Buccafusco and published by CRC Press. This book was released on 2000-08-29 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using the most well-studied behavioral analyses of animal subjects to promote a better understanding of the effects of disease and the effects of new therapeutic treatments on human cognition, Methods of Behavior Analysis in Neuroscience provides a reference manual for molecular and cellular research scientists in both academia and the pharmaceutic
Download or read book Genomic Identification and Functional Characterization of Essential Genes in Caenorhabditis Elegans written by Zhaozhao Qin and published by . This book was released on 2016 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: For over 30 years, researchers have taken advantage of genetic balancers and forward genetic screens to isolate lethal mutations, which have been studied to identify essential genes in C. elegans. Using traditional genetic methods, such as genetic mapping, complementation tests, and transgenic rescue assays, many essential genes have been successfully identified. However, to pinpoint a specific essential gene the involved experiments are usually labor intensive and time consuming. Nowadays, genetic methods combined with whole genome sequencing (WGS) and bioinformatics analysis provide an effective approach for the molecular identification of essential genes. In my thesis I successfully identified 64 new essential genes with 107 lethal mutations in genomic regions of C. elegans of around 14 Mb from Chromosome III(mid) and Chromosome V(left), by combining genetic mapping, Illumina sequencing, bioinformatics analyses, and experimental validation. Most of these genes have multiple recovered mutant alleles. Of these 64 genes 5 have new alleles identified, which had not been previously studied by RNA interference depletion. Furthermore, by investigating the locations of lethal missense mutations in essential genes, I have identified five novel protein functional domains. Functional characterization of the identified essential genes shows that most of them are enzymes, including helicases, tRNA synthetase, and kinases. There are also ribosomal proteins. Gene Ontology functional annotation also indicates that essential genes tend to execute enzyme and nucleic acid binding activities during fundamental processes, such as intracellular protein synthesis. Essential gene analysis shows that compared to non-essential genes, essential genes have fewer paralogs, and encode proteins that are in protein interaction hubs. Essential genes are also more abundantly and consistently expressed over all developmental stages than non-essential genes. All these essential genes traits in C. elegans are consistent with those of human disease genes. Unsurprisingly, most (90%) human orthologs of essential genes in this study are related to human diseases. Therefore, functional characterization of essential genes underlines their importance as proxies for understanding the biological functions of human disease genes.
Download or read book Phenotypes and Genetic Mechanisms of C Elegans Enhanced RNAi written by Jimmy Jiajia Zhuang and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: RNA interference (RNAi) potently and specifically induces gene knockdown, and its potential for reverse genetics in Caenorhabditis elegans is enormous. However, even in these nematodes, RNAi can be induced more effectively via enhanced RNAi (Eri) mutant backgrounds. With advances in small RNA sequencing, evidence has suggested that the eri pathway plays an endogenous gene regulatory role, which competes with experimentally introduced RNAi triggers for limiting resources. However, the nature, cellular location, and physiological consequences of this small RNA pathways competition remain unclear. To answer these questions, I first fully characterized the genetic phenotypes of all known Eri mutants. I discovered that different components of the eri pathway have subtle differences upon mutation, which affects more than exogenous RNAi. I then attempted to screen for novel enhanced RNAi mutants, guided by hypothetical mechanisms or tissues of expression not associated with known mutants. After these attempts, I fully characterized the genetic mechanisms that account for enhanced RNAi. Surprisingly, I discovered that the nuclear Argonaute nrde-3 and the peri-nuclear P-granule component pgl-1 are necessary and sufficient for an Eri response. Finally, I examined the impact of the competition among microRNA, endogenous siRNA, and exogenous RNAi pathways. I discovered that C. elegans develops slower upon perturbations to its normal flux of small RNA pathways. Insights from these phenotypes and genetic mechanisms shed light on the importance of small RNA biology and offer a novel suite of tools for sensitizing RNAi in broader contexts, especially given the deep evolutionary conservation of most eri-associated genes.
Download or read book Large scale RNAi Screen to Identify Genes Involved in Axon Guidance in Caenorhabditis Elegans written by Parag Kinge and published by . This book was released on 2005 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Identification of New Regulators of Phase II Detoxification Gene Expression by a Genome wide RNAi Screen in Caenorhabditis Elegans written by Helen Marie Crook and published by . This book was released on 2011 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using RNA Interference to Identify Genes Involved in C Elegans Gastrulation written by Stephanie Marie Glass and published by . This book was released on 2011 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Biochemical Mechanisms Underlying Nuclear RNA Interference in C Elegans written by Alexandra Lewis and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "RNA interference (RNAi) pathways regulate gene expression in almost all eukaryotes in a sequence-specific manner that depends on complementarity between a small RNA and an mRNA target. In order to effect target silencing, small RNAs are loaded onto Argonautes that can silence their targets post-transcriptionally in the cytoplasm, or transcriptionally in the nucleus in a process called nuclear RNAi. Nuclear RNAi pathways play important roles in organismal development, defense against viruses and transposable elements, and chromosomal organization. Nuclear RNAi links small RNA pathways with chromatin modifications that can, in some cases, be passed on to the next generation. In C. elegans for example, nuclear RNAi triggers heterochromatic histone methylation that can be inherited for many generations. While many of the major genes involved in the pathway are known, it remains unclear how Argonautes and the nuclear RNAi machinery are regulated and how they recruit chromatin-modifying proteins.Through a combination of genetic and biochemical assays, the research presented in this thesis outlines specific mechanisms through which nuclear RNAi in C. elegans is regulated and demonstrates physical links between proteins that provide clarity on how silencing is achieved. We identified a novel family of nuclear Argonaute binding proteins (the ENRIs) and demonstrated the mechanism by which they control the strength and target specificity of nuclear RNAi. ENRI-1/2 prevent misloading of the nuclear Argonaute NRDE-3 with aberrant small RNAs, and in doing so prevent the premature nuclear localization of NRDE-3 in early embryos. Loss of ENRI-3 impairs inheritance of RNAi phenotypes and leads to misregulation of small RNAs. In addition, we showed that post- translational modifications of ENRI-2 affect many aspects of its function. Phosphorylation6of ENRI-2 impairs nuclear RNAi and alters its localization. Finally, we showed how the nuclear RNAi machinery assembles in the nucleus and demonstrated physical links between some of these proteins for the first time. We found that two of these proteins, NRDE-1 and NRDE-4, form a stable complex that form a signaling platform that is required for heritable nuclear RNAi through the recruitment of a phosphatase.Overall, this thesis delineates novel modes and layers of regulation of the nuclear RNAi pathway and provides important biochemical insight into the pathway's mechanism"--
Download or read book Identifying Genes Involved in RNA Interference in Caenorhabditis Elegans written by Diana Rothenstein and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Identification of Dyn 1 from an RNAi Screen on Chromosomes I IV and X for Genes Involved in Apoptotic Cell Corpse Engulfment in C Elegans written by Johann Almendinger and published by . This book was released on 2005 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
