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[
International Worm Meeting,
2015]
More than 2 billion people world-wide are estimated to be infected with parasitic nematodes, resulting in major economic and personal impacts from the years of life lost to poor health and premature mortality. The identification of drugs that can cheaply and effectively treat parasitic nematode infections is a critical global health need. However, the journey from initial drug development to approval for use in humans is long and costly, and screening directly on parasitic nematodes has intrinsic difficulties caused by the requirements for culturing and maintaining populations of parasites. It is likely that compounds that kill C. elegans will also kill parasitic nematodes, making C. elegans a cost-effective and rapid screening tool to identify new anthelmintics. To expedite the identification of drugs that can be rapidly translated into clinical use for parasite treatment, we are screening commercially available libraries of drugs approved for use in humans. These libraries represent drugs with known safety, bioavailability, and dosage information for use in humans that can be rapidly repurposed for treatment of parasitic nematode infections. Initial library screening has identified 92 compounds that kill C. elegans. These include known anthelmintics (Mebendazole, Pyrvinium pamoate, Tiabendazole, Niridazole, Levamisole, Pentamidine isethionate, Fenbendazole, Avermectin B1), as well as unexpected hits such as anti-Parkinsonian drugs. Numerous therapeutic groups are represented in the hits, including analgesics, antibacterial agents, antidepressants, antifungals, antihistamines, and antipsychotics. Continued testing will select for agents that are effective against multiple life stages (embryos, larval, dauer, and adult). Candidates will also be screened against databases of existing information to select agents with oral bioavailability, few side-effects in humans, and low cost for production. Compounds meeting these criteria will be given preference for follow-up testing. Our preliminary results indicate C. elegans may represent a powerful surrogate for large scale anti-nematode drug screening.
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[
International Worm Meeting,
2015]
Accumulation of the protein TDP-43 in neuronal aggregates is the major pathological feature of two devastating neurodegenerative diseases, amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTLD-TDP). TDP-43 is an essential protein and is involved in many aspects of RNA metabolism from transcription to translation, although its most critical contribution may be regulation of the majority of cellular mRNA splicing events. Disruption of the normal activity of TDP-43, either by mutation of TDP-43 or alterations in TDP-43 regulatory pathways, promotes neuronal dysfuction and degeneration in a variety of model systems including C. elegans, Drosophila, zebrafish, mammalian cell culture, and mice. To study the cellular, molecular, and genetic underpinnings of TDP-43 mediated neurotoxicity in a tractable model system, we have developed C. elegans models of TDP-43 proteinopathy expressing either wild type or disease-causing mutant TDP-43 pan-neuronally (TDP-43 tg). These transgenic animals display early, progressive motor dysfunction, decreased lifespan, and age-dependent degeneration of specific types of neurons, including GABA-ergic and dopaminergic neurons (1). However, not all TDP-43 expressing neurons undergo apparent neurodegeneration, indicating differences in sensitivities of specific populations of neurons to the presence of TDP-43. Surveying the range of responses to TDP-43 may provide a set of shared characteristics for populations of neurons susceptible or resistant to aberrant TDP-43. To investigate neuronal function in TDP-43 tg animals, we are utilizing a panel of behavioral, stress response, and stress survival assays. Results from these assays have identified individual sensory neurons with functional impairments in the absence of early neuronal cell body degeneration. These TDP-43 sensitive neurons will allow dissection of the effects of neurotoxic TDP-43 on neuronal function, and provide insight into the upstream processes leading to TDP-43 dependent neurodegeneration. 1. N. F. Liachko, C. R. Guthrie, B. C. Kraemer, Phosphorylation Promotes Neurotoxicity in a Caenorhabditis elegans Model of TDP-43 Proteinopathy. J Neurosci 30, 16208-16219 (2010).
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Zhen, Mei, Kasthuri, Bobby, Shalek, Richard, Lichtman, Jeff, Samuel, Aravi, Pfister, Hanspeter, Laskova, Valeriya, Kaynig-Fittkau, Verena, Wen, Quan, Berger, Daniel, Guan, Asuka
[
International Worm Meeting,
2013]
To investigate the poorly understood mechanisms of development and function of the nervous system, connections between neurons must be deciphered first. The adult nervous system of C. elegans was mapped to near completion by Dr. John White and his colleagues in 1970s. However, neuronal wiring in C. elegans larvae differs from that of an adult, since it undergoes multiple rounds of neuronal birth, apoptosis and rewiring during development. We utilize an Automatic Tape-Collecting Ultramicrotome (ATUM) to section an entire L1 stage animal into thousands cross-sections, followed by the automated imaging with a scanning electron microscope (SEM) to map an entire neuronal wiring diagram with synaptic resolution. The acquired wiring diagram will guide and be validated by calcium imaging to map the functional connection of the juvenile motor circuit.
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[
Neuronal Development, Synaptic Function, and Behavior Meeting,
2006]
The networks of nerves and muscles responsible for forward and backward movements in C. elegans offer unique advantages for investigating the functional relationships among cells in integrated cellular networks. The first advantage is that John Sulston and his colleagues identified the interneurons, motor neurons and muscle cells that compose the networks (Sulston, et al., 1983). Second, John White and colleagues determined the synaptic patterns that interconnect the network (White et al., 1986). Finally, the C. elegans community has generated mutations that cause specific alterations in the cellular networks. A model based on the connectivity pattern and laser ablation results suggests that distinct sets of interneurons and excitatory motor neurons are dedicated to forward and backward movement, respectively. These two circuits converge upon two classes of inhibitory motor neurons and four longitudinal strands of body wall muscles and create antiphasic contractile muscular waves that travel along the dorsal and ventral axes of the body. We will report results from the analysis of movies showing locomotion patterns of animals. These movies allows us to quantitatively characterize the traveling wave in terms of amplitudes, dorsal and ventral deflections, frequency and velocity of the wave progression and the forward and backward velocity of the animal's progression. We will compare wild-type locomotion characteristics with those exhibited by three uncoordinated mutants (
unc-4,
unc-55, and
cnd-1) that are known to make specific alterations in the network that result in movement defects that are predicted by the model. The connectivity model can also be used to predict epistatic relationships for double mutant combinations (for example
unc-55 mutants exhibit a ventral asymmetric pattern of backward movement, whereas
unc-4 exhibits a dorsal asymmetric pattern of backward movement). We find that
unc-4 masks the defect of
unc-55 mutants, which is predicted by the model neural circuit. However the model's predictions for forward movement are not as accurate. We will discuss possible explanations for the resiliency of forward movement and the vulnerability of backward movement to genetic perturbations.
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[
West Coast Worm Meeting,
2000]
We briefly describe the current status and plans for WormBase, initially an extension of the existing ACeDB database with a new user interface. The WormBase consortium includes the team that developed ACeDB (Richard Durbin and colleagues at the Sanger Centre; Jean Thierry-Mieg and colleagues at Montpellier); Lincoln Stein and colleagues at Cold Spring Harbor, who developed the current web interface for WormBase; and John Spieth and colleagues at the Genome Sequencing Center at Washington University, who along with the Sanger Centre team, continue to annotate the genomic sequence. The Caltech group will curate new data including cell function in development, behavior and physiology, gene expression at a cellular level, and gene interactions. Data will be extracted from the literature, as well as by community submission. We look forward to providing the C. elegans and broader research community easy access to vast quantities of high quality data on C. elegans. Also, we welcome your suggestions and criticism at any time. WormBase can be accessed at www.wormbase.org.
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[
Japanese Worm Meeting,
2002]
The synaptic connectivity of C. elegans is well known from observations of the somatic system by White et al. and those of the pharyngeal system by Albertson et al. So far, three databases were constructed for computational usage by Achacoso et al. and Durbin, and recently in WormBase. However, they lack some data such as those in tables of White's paper and those in figures of Albertson's book. Our database (K. Oshio, S. Morita, Y. Osana and K. Oka: Technical Report of CCEP, Keio Future No.1, 1998) includes all data described in White's paper and Albertson's book. Unfortunately, some mistakes were found in the database through private communications with John White who is the author of White's paper and with the users of the database. Thus we have been proceeding with the revision to make it perfect one. We are planning to complete the revision in September 2002. The database should be worthwhile not only for neurophysiological studies, but also for post-genomic interests mediating genomes and behavior.
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[
Neuronal Development, Synaptic Function, and Behavior Meeting,
2006]
We describe a novel instrument, The Swept-Field Confocal Microscope (SFC) that combines high resolution pinhole imaging with slit imaging. Unlike spinning disk confocal systems that have their pinhole apertures embedded in a spinning disc, the SFC's 32 pinhole array remains stationary. Galvonometric and piezo controlled mirrors sweep the image of the pinholes across the sample. The emission photons are de-scanned and focused through a complementary set of pinholes onto a CCD camera. This results in a high resolution image that can be collected at up to 100 frames/second in the pinhole mode and greater than 1000 frames per second in the slit mode. The ability for the scientist to match the optical recording with the temporal biological fluorescence response has great promise for cell and developmental biology studies where live dynamic events must be captured quickly in high resolution. In this poster we describe the optical path of the microscope and present some early data in collaboration with John White's group at the UW-Madison of using the SFC to image GFP constructs in C .elegans to investigate cell division in the early embryo.
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[
International Worm Meeting,
2007]
The Hall lab is the home for the physical EM data for C. elegans that was collected by many scientists working at several key laboratories over the past 40 years. We have almost all of the annotated prints, negatives, data notebooks and often the original thin sections and blocks from the MRC, Missouri, Caltech and AECOM collections, including the work of John White, John Sulston, Sam Ward, and many others. This archive includes wild type and mutant data, and covers both males and hermaphrodites, and all ages from embryo to adulthood, and some aging animals. We are scanning much of this physical print data to produce a digital archive of C. elegans anatomy. We have generated about 3 terabytes of digital images, and there is much more scanning to be done. We have designed a simple online photo album, WormImage, to share some of this archive as small thumbnail versions that can quickly transit across the Internet to all users, for free. Bandwidth issues limit our ability to ship full size scans electronically, but we also supply users with higher resolution scans upon request, by ftp or on DVDs. WormImage (www.wormimage.org) is an online database developed for remote retrieval of this digitized microscopy data. Currently this database contains about 20,000 different digital images. Most scans have been taken from the workprints, to preserve original hand annotations which mark identified cell types. The WormImage database is updated weekly to provide more images. The user can search this database by animal name, age, sex, or by regional information (head, midbody, tail) or by tissue types to identify potential images of interest. The user can quickly survey many animals in small thumbnail images, or concentrate on details of a few images expanded to larger size. The program was recently revised to make it easy for the user to click through all the thumbnails for one animal in serial order. Hall has been reviewing the original annotations and writing brief summaries for each animal, also offered on the website. These Color Code summaries help to translate the shorthand markings on the original prints into the familiar cell names for many structures. During 2007, WormImage will begin showing images of key mutant phenotypes and aging animals. We are grateful to Demian Nave and Art Wetzel at the Pittsburgh Supercomputing Center for their help in providing a mirror site. This work is funded by NIH RR 12596.
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[
International C. elegans Meeting,
1991]
unc-40 is required with
unc-6 to guide ventral migrations on the nematode epidermis (Hedgecock et al., Neuron 4, 61-85, 1990). We have positioned
unc-40 genetically by 3-factor crosses with
dpy-5 and
bli-4 as flanking markers and we have isolated 5 new alleles of
unc-40 (2 spontaneous, 2 gamma, and 1 EMS) making a total of 12. DNAs from cosmids covering this region (obtained from Alan Coulson and John Sulston) are being used to probe DNA and RNA from the mutants and DNA from strains carrying duplications that break to either side of
unc-40 (obtained from Anne Rose's laboratory). We are also injecting cosmid DNAs into gonads to look for rescue by germline transformation. The brood sizes of various
unc-40 alleles are very small, so we have resorted to injecting the wild type in order to create a series of transformed lines, each carrying an extrachromosomal array of a different cosmid. Each array will be passed into appropriately marked
unc-40 animals to ask if any can rescue the mutant phenotype. Mosaic experiments are also underway to determine whether
unc-40 acts in migrating cells.
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[
European Worm Meeting,
2006]
Jane Shingles1, John Reece-Hoyes1, Denis Dupuy2, Marc Vidal2 and Ian Hope1. The Promoterome library containing 6500 Caenorhabditis elegans promoter fragments has previously been generated and used to construct promoter ::GFP fusions to allow determination of gene expression patterns in C. elegans. Optimization of the C. elegans micro-particle bombardment transformation technique, to give a medium through-put system, allowed the generation of expression patterns for over 300 C. elegans promoter::GFP fusions. Promoter fusion constructs of transcription factors genes and genes with homology to human genes with no assigned function were selected for the initial analysis and the results are shown. Initial analysis of the results highlights several significant differences between the two sets of genes. Promoters from C. elegans homologues of human genes with no known function were far more likely to yield either no GFP expression (35% vs. 6%) or ubiquitous GFP expression (23% vs. 8%) under the standard laboratory conditions utilized. In contrast, promoters from C. elegans transcription factor genes were far more likely to drive neuronal expression (62% vs.16%).. Full results are presented on the Hope Laboratory Expression Pattern database URL
:http://bgypc059.leeds.ac.uk /~web