Sandrine Fraboulet et al. (2009) European Worm Neurobiology Meeting "Chemical rescue of paralysis in a transgenic model of Caenorhabditis elegans overexpressing human Beta-amyloid"

David I C Scopes, Andrew K Jones, David B Sattelle, Aileen Moloney, Christopher D Link, Steven D Buckingham, Mark J Treherne, Hozefa Amijee, Sandrine Fraboulet

[European Worm Neurobiology Meeting, 2009]

Authors acknowledge support from MRC. Numerous studies support a role for aggregated Ab as a mediator of the toxicity that underlies Alzheimer.s disease (AD) and other diseases such as Inclusion Body myositis (IBM), an acquired muscle disease affecting people over 50 years old. In this pathology, muscle weakness and degeneration is accompanied by chronic muscle inflammation. Remarkably, despite the inflammation component of the disease, IBM patients are only poorly responsive to anti-inflammatory drugs suggesting that inflammation per se may not be the primary cause of the pathology. We have used a C. elegans transgenic line over-expressing human amyloid 1-42 peptide in the muscles as a model with which to test the efficiency of new compounds on in vivo amyloid toxicity. This C. elegans line becomes paralyzed shortly after the induction of amyloid expression in the muscles, which makes it an easily-recordable phenotype useful for exploring candidate treatments to alleviate the paralysis. We report on the actions of two novel chemicals, which inhibit amyloid aggregation and partially rescue the amyloid-induced phenotype. References: Wu Y, W.Z., Butko P, Christen Y, Lambert MP, Klein WL, Link CD, Luo Y. (2006) J. Neurosci., 26, 13102-13. Link CD, T.A., Kapulkin V, Duke K, Kim S, Fei Q, Wood DE, Sahagan BG. (2003) Neurobiol Aging., 24, 397-413. Jones, A.K., Buckingham, S.D. and Sattelle, D.B. (2005). Nat Rev Drug Discov, 4, 321-30.

Blackwell, Alexander et al. (2021) International Worm Meeting "Studying chromatin regulation at single cell resolution during C. elegans postembryonic development"

Gaarenstroom, Tessa, Van den Heuvel, Sander, Blackwell, Alexander

[International Worm Meeting, 2021]

Despite containing identical genomes, developing cells differentiate into a plethora of diverse cell types. Distinct patterns of gene expression now form the basis for classifying different cell fates. How the combinatorial activity of transcription factors, chromatin regulators and histone modifications achieve the proper spatiotemporal patterns of gene expression is a major question in developmental biology. Biologists increasingly appreciate the need to investigate gene expression regulation at the single-cell level because much heterogeneity and complexity is lost when averaging across populations of cells. However, profiling chromatin at the single cell level is challenging due to limited input material. Chromatin immunocleavage with sequencing (ChIC-seq) is an efficient method to study chromatin modifications from low input samples. ChIC-seq utilises antibody targeted micrococcal nucleases, leading to controlled, binding-dependent enzymatic digestion of DNA. This releases short fragments which become preferentially incorporated during library preparation and enables high resolution mapping of genomic positions. Crucially, the absence of crosslinking and immunoprecipitation steps, required in less sensitive techniques such as ChIP-seq, leads to minimal material loss. Recently, ChIC-seq was used to profile histone modifications in single human cells [1]. Adapting ChIC-seq to profile histone modifications in C. elegans will provide a powerful tool for studying the epigenetic regulation of development. Here, we present progress in optimising ChIC-seq for profiling chromatin modifications at single-cell level across a developmental time-course in C. elegans. Specifically, we combine Cre/Lox lineage tracing with cell isolation and FACS procedures in order to isolate postembryonic mesoderm cells. Following prolonged quiescence, the mesoblast precursor resumes proliferation and produces fourteen muscle cells, two scavenger cells, and two migratory bipotent myoblasts over 24-hours. By profiling chromatin modifications at high temporal resolution, we aim to reveal regulatory processes controlling cellular proliferation and differentiation. This work will shed light on how epigenetic modifications contribute to cellular decision making in a living animal. [1] Ku WL, Nakamura K, Gao W, Cui K, Hu G, Tang Q, Ni B, Zhao K. (2019) Single-cell chromatin immunocleavage sequencing (scChIC-seq) to profile histone modification. Nature Methods, vol. 16, pages 323-325.

Yang Zhao et al. (2005) International Worm Meeting "Worms in space"

Yang Zhao, Robert Johnsen, Ann Rose, David Baillie

[International Worm Meeting, 2005]

It is well known that radiation causes mutational damage, which can result in susceptibility to cancer, radiation-sickness, and death at high dosages. However, little is known about the biological effects of long-term exposure to radiation in space because of the technical difficulties involved in placing a multicellular model organism in a space environment for long time periods. One possibility for such study is use of the easy-maintainable, self-fertilizing hermaphroditic nematode, Caenorhabditis elegans. C. elegans has many characteristics that make it an excellent model system for use in space. Maintenance of C. elegans is relatively easy: it is small and can be fed/cultured in a chemically defined axenic media (CeMM)[1,2]. Worms will survive for several months in CeMM, and can be maintained indefinitely by passage to fresh media. Samples can be isolated in space for relatively large scale mutational analysis on Earth. The wide variety of research resources available for biological analysis in C. elegans provides a promising backdrop for the development of the system to study the effects of traveling and living in space. The ICE-First, 1st International Caenorhabditis elegans Experiment, was organised by Michel Viso (Centre National detudes Spatiales) in collaboration with investigators from Canada, France, Japan and the US, aimed to use C. elegans as a model system for biological studies in space. The launch occurred on April 19, 2004 and the landing on April 30, 2004. The goal of the Canada group project was to measure the mutational effects of the flight and stay on the Space Station. Two strains were examined: CC1 (widetype) obtained from C. Conley, NASA[2], and BC2200 (dpy-18; unc-46/eT1) from D. Baillie, SFU[3,4,5]. Both strains were grown in CeMM and several approaches were taken to measure potential mutational changes, including whole genome microarray analysis, deletion of poly-G stretches, occurrence of unc-22 mutations, lethal mutations, and alterations in telomere length. The worms from the flight are being analysed and compared to ground and laboratory controls for genetic alterations. No significant difference in the mutation rate was detected between the flight samples and the control. However, our studies demonstrate the advantage of the system in the potential to develop a biological integrating dosimeter for long term space travel. Funded by the Canadian Space Agency (CSA). References 1 Lu NC, Goetsch KM. Nematologica 1993;39: 303331 2 Szewczyk NJ et al. BMC Biotechnol 2003 3(1): 19 3 Rosenbluth RE et al. Genetics 1981 99(3-4): 415-28 4 Rosenbluth RE et al. Mutation Research 1983 110(1): 39-48 5 Johnsen and Baillie Genetics 1991 129(3):735-52