Schiffer, Jodie et al. (2017) International Worm Meeting "How do worms determine their readiness to cope with environmental stress?"

Stumbur, Stephanie, Heath, William, Tam, Hannah, McGowan, Natalie, Vogelaar, Abigail, Schiffer, Jodie, Apfeld, Javier, Stanley, Julian

[International Worm Meeting, 2017]

At any time in their life, worms may encounter harmful environmental conditions such as high concentrations of oxidants or high temperature. We are interested in understanding how worms prepare for these potentially lethal events. We want to know: what establishes how prepared they are? To determine the mechanisms that control survival under harmful conditions, we are examining the effects of strong loss-of-function and null mutants in a collection of intercellular signaling receptors and transcription factors regulated by these receptors. We measure survival under oxidative stress and at high temperature using a "Lifespan Machine" cluster of flat-bed scanners [1]. This automated technology presents substantial advancements in throughput and sensitivity compared to manual methods. Using this approach, we have identified several signaling receptors and transcription factors that regulate survival under oxidative conditions. Interestingly, we identified both receptors and transcription factors that function to either confer or limit oxidative-stress resistance. This indicates that the combined level of activity of these genes sets the worm's readiness to cope with oxidative stress. We are currently investigating whether these genes act together or independently to determine the worm's normal level of resistance to various stressors, and the mechanisms that establish the normal activity levels of each of these genetic determinants of stress resistance. Reference: 1. Stroustrup N, Ulmschneider BE, Nash ZM, Lopez-Moyado IF, Apfeld J, Fontana W. The Caenorhabditis elegans Lifespan Machine. Nature Methods. 2013;10(7):665-70.

Schiffer, J. et al. (2019) International Worm Meeting "Sensory neurons specifically regulate hydrogen-peroxide protection by target tissues via a multistep hormonal relay."

Stumbur, Stephanie, Schiffer, J., Johnsen, Sean, Apfeld, Javier, Stanley, Julian, Servello, Francesco, Vogelaar, Abigail, Heath, William, McGowan, Natalie

[International Worm Meeting, 2019]

Hydrogen peroxide is a common weapon that species use for offensive purposes. Cells use conserved defense mechanisms to prevent and repair peroxide damage, but whether these responses are coordinated across cells in multicellular organisms is poorly understood. We determined whether sensory neurons control hydrogen-peroxide protective responses in C. elegans</em>. We measured the peroxide tolerance of a collection of sensory-neuron genetic-ablation strains using a Lifespan Machine assay and identified ten types of taste, smell, oxygen- and temperature- sensing neurons with significant positive or negative effects on peroxide tolerance. How do specific sensory neurons control whether target tissues protect the animal from hydrogen peroxide? Using genetic and site-of-action studies, we found that ASI sensory neurons secrete DAF-7, a TGF? hormone, to specifically lower hydrogen peroxide tolerance. The DAF-7 receptor, DAF-1, acts redundantly in at least three different sets of interneurons to lower peroxide tolerance. DAF-1 inhibits transcription by the DAF-3 coSMAD. We find this inversion of the ASI signal ensures that peroxide tolerance stays low until a decrease in DAF-7 causes multiple sets of interneurons to activate DAF-3. DAF-3 does not regulate peroxide tolerance via dauer, germline, or fat pathways. Instead, we find that by lowering the expression of DAF-2 insulin/IGF1 receptor ligands (Narasimhan et al., 2011; Shaw et al., 2007) DAF-3 triggers a peroxide-protective response via de-repression of DAF-16 FOXO transcription in neurons and intestine. Together, TGF? and insulin/IGF1 pathways form a hormonal relay that may enable ASI to sensitively induce a peroxide-protective response in target tissues. Both ingestion and perception of E. coli appear to regulate DAF-7 signaling. E. coli ingestion increases peroxide tolerance but inhibits DAF-3. As a result, DAF-3 alleviates the decrease in peroxide tolerance that occurs when E. coli ingestion is reduced. Perception of E. coli likely lowers the worm's peroxide tolerance via DAF-7, because E. coli promotes daf-7 expression in ASI (Chang et al., 2006; Entchev et al., 2015) . Why does E. coli perception by ASI lower the worm's peroxide tolerance? We find that hydrogen peroxide degrading enzymes from E. coli protect C. elegans from hydrogen peroxide killing. We propose that C. elegans uses sensory information to decide whether it needs to induce its own hydrogen-peroxide protection or bacteria will protect them instead.

Kearn J et al. (2013) Invert Neurosci "Meeting report: 2012 Caenorhabditis elegans Neurobiology meeting, EMBL Advanced Training Centre, Germany."

Dalliere N, Dillon J, Kearn J

[Invert Neurosci, 2013]

Some of the finest minds in the field of Caenorhabditis elegans neurobiology were brought together from 14 June to 17 June 2012 in the small, quaint and picturesque German city of Heidelberg for the biannual C. elegans neurobiology conference. Held at the EMBL Advanced Training Centre and wonderfully organised by Diah Yulianti, Jean-Louis Bessereau, Gert Jansen and William Schafer, the meeting contained 62 verbal presentations and hundreds of posters that were displayed around the double-helical walkways that looped throughout the conference centre. Presentations on recent advances in microfluidics, cell ablation and targeted gene expression exemplified the strengths of C. elegans as a model organism, with these advances allowing detailed high-throughput analysis and study. Interesting behaviours that were previously poorly characterised were widely discussed, as were the advantages of C. elegans as a model for neurodevelopment and neurodegeneration and the investigation of neuropeptide function. The examples discussed in this meeting report seek to illustrate the breadth and depth of presentations given on these recurring topics.

Sela N et al. (2008) Biol Direct "Transduplication resulted in the incorporation of two protein-coding sequences into the turmoil-1 transposable element of C. elegans."

Ast G, Makalowski W, Sela N, Pupko T, Stern A

[Biol Direct, 2008]

ABSTRACT: Transposable elements may acquire unrelated gene fragments into their sequences in a process called transduplication. Transduplication of protein-coding genes is common in plants, but is unknown of in animals. Here, we report that the Turmoil-1 transposable element in C. elegans has incorporated two protein-coding sequences into its inverted terminal repeat (ITR) sequences. The ITRs of Turmoil-1 contain a conserved RNA recognition motif (RRM) that originated from the rsp-2 gene and a fragment from the protein-coding region of the cpg-3 gene. We further report that an open reading frame specific to C. elegans may have been created as a result of a Turmoil-1 insertion. Mutations at the 5'' splice site of this open reading frame may have reactivated the transduplicated RRM motif. Reviewers: This article was reviewed by Dan Graur and William Martin. For the full reviews, please go to the Reviewers'' Reports section.

Fonte V et al. (2002) Proc Natl Acad Sci U S A "Interaction of intracellular beta amyloid peptide with chaperone proteins."

Taft A, Link CD, Friedman D, Fonte V, Fluet A, Kapulkin V

[Proc Natl Acad Sci U S A, 2002]

Communicated by William B. Wood, University of Colorado, Boulder, CO, May 24, 2002 (received for review March 22, 2002) Expression of the human ss amyloid peptide (Ass) in transgenic Caenorhabditis elegans animals can lead to the formation of intracellular immunoreactive deposits as well as the formation of intracellular amyloid. We have used this model to identify proteins that interact with intracellular Ass in vivo. Mass spectrometry analysis of proteins that specifically coimmunoprecipitate with Ass has identified six likely chaperone proteins: two members of the HSP70 family, three alphaB-crystallin-related small heat shock proteins (HSP-16s), and a putative ortholog of a mammalian small glutamine-rich tetratricopeptide repeat-containing protein proposed to regulate HSP70 function. Quantitative reverse transcription--PCR analysis shows that the small heat shock proteins are also transcriptionally induced by Ass expression. Immunohistochemistry demonstrates that HSP-16 protein closely colocalizes with intracellular Ass in this model. Transgenic animals expressing a nonaggregating Ass variant, a single-chain Ass dimer, show an altered pattern of coimmunoprecipitating proteins and an altered cellular distribution of HSP-16. Double-stranded RNA inhibition of R05F9.10, the putative C. elegans ortholog of the human small glutamine-rich tetratricopeptide-repeat-containing protein (SGT), results in suppression of toxicity associated with Ass expression. These results suggest that chaperone function can play a role in modulating intracellular Ass metabolism and toxicity.

Parween N et al. (2021) CNS Neurol Disord Drug Targets "Eugenol Elicits Prolongevity by Increasing Resistance to Oxidative Stress in C. elegans."

Jabeen A, Parween N, Prasad B

[CNS Neurol Disord Drug Targets, 2021]

AIM: To analyze the efficacy of eugenol on longevity by assessing its antioxidant effect using Caenorhabditis elegans as an animal model. BACKGROUND: Eugenol is a major polyphenolic component of Ocimum sanctum (Tulsi) which attributes wide pharmacological activities and can serve as a biomarker. However, the possible effect of eugenol on longevity in Caenorhabditis elegans has not been reported. OBJECTIVE: The objective of this investigation was to provide first scientific based results about effect of eugenol on longevity, slowing down of paralysis in Alzheimer's model and mechanism behind it in Caenorhabditis elegans animal model system. METHODS: The phenolic components of methanolic extract of Ocimum sanctum was analyzed by RP-HPLC. Worms were exposed to different concentrations of extract and one of its components -eugenol. Lifespan, health span, survival in CL4176 Alzheimer's model and molecular mechanism were analyzed. RESULTS: Extract of Ocimum sanctumand eugenol increased lifespan and provided indemnity against pro-oxidants. It also significantly improved healthy ageing and slowed the progression of neurodegeneration in CL4176 Alzheimer's model of worm by increasing survival against prooxidants and slowing down the paralysis. Longevity effect was independent of the DAF-16 as observed by using DAF-16::GFP and daf-16 null mutant strains. These results implicate eugenol as a potent therapeutic compound which may curtail ageing and age related disorders like- Alzheimer's disease. CONCLUSION: The present work demonstrated eugenol as a potential anti-ageing compound which may curtail ageing, improve heath span by enhancing resistance to oxidative stress and exerts its effect independent of DAF-16 pathway. So, it can be assumed that eugenol can be beneficial to humans as well, albeit further research is necessary before declaring it for human consumption.

Yu S et al. (2018) BMC Genomics "Genomic identification and functional analysis of essential genes in Caenorhabditis elegans."

Rose AM, Baillie DL, Zhou F, Deng Z, Zheng C, Chu JS, Yu S

[BMC Genomics, 2018]

BACKGROUND: Essential genes are required for an organism's viability and their functions can vary greatly, spreading across many pathways. Due to the importance of essential genes, large scale efforts have been undertaken to identify the complete set of essential genes and to understand their function. Studies of genome architecture and organization have found that genes are not randomly disturbed in the genome. RESULTS: Using combined genetic mapping, Illumina sequencing, and bioinformatics analyses, we successfully identified 44 essential genes with 130 lethal mutations in genomic regions of C. elegans of around 7.3Mb from Chromosome I (left). Of the 44 essential genes, six of which were genes not characterized previously by mutant alleles, let-633/let-638 (B0261.1), let-128 (C53H9.2), let-511 (W09C3.4), let-162 (Y47G6A.18), let-510 (Y47G6A.19), and let-131 (Y71G12B.6). Examine essential genes with Hi-C data shows that essential genes tend to cluster within TAD units rather near TAD boundaries. We have also shown that essential genes in the left half of chromosome I in C. elegans function in enzyme and nucleic acid binding activities during fundamental processes, such as DNA replication, transcription, and translation. From protein-protein interaction networks, essential genes exhibit more protein connectivity than non-essential genes in the genome. Also, many of the essential genes show strong expression in embryos or early larvae stages, indicating that they are important to early development. CONCLUSIONS: Our results confirmed that this work provided a more comprehensive picture of the essential gene and their functional characterization. These genetic resources will offer important tools for further heath and disease research.

Gu GQ et al. (1994) Worm Breeder's Gazette "mec-5 Encodes a Collagen Needed For Touch Sensitivity."

William CM, Chalfie M, Gu GQ

[Worm Breeder's Gazette, 1994]

mec-5 Encodes a Collagen Needed for Touch Sensitivity Guoqiang Gu, Chris William, and Marty Chalfie, Department of Biological Sciences, Columbia University in the City of New York, NY 10027 mec-5 is one of the genes required for mechanosensitivity in C. elegans. Although the touch receptor neurons do not function, they appear morphologically normal in mec-5 mutants. Peanut-lectin binding to the touch cell mantle, however, is absent (M. Chalfie and E. Hedgecock, unpublished data). By transformation rescue, we identified a 6.5 kb BamHI-Kpnl fragment in cosmid E03G2 which completely rescues the mec-5 phenotype. We isolated a 1.2 kb full length cDNA (Northern blots show a 1.2 kb mRNA) from the Chris Martin cDNA library. The cDNA sequence encodes a collagen. The protein (329 aa) has a 20 amino acid putative signal sequence at the N- terminus and 69 Gly-X-Y repeats starting at aa 63. These collagen repeats are followed by 60 additional amino acids. Because collagens are often glycosylated on hydroxyproline residues, the loss of MEC-5 may explain the lack of peanut- lectin binding. To verify that this collagen gene is mec-S, we probed genomic Southern blots with the 6.5 kb fragment and found that the 6.5 kb fragment was deleted in two mec-5 strains, the mut-2 derived strain TU828 and the Y-ray strain TU1031. We are now sequencing other mec-5 mutations and characterizing the expression pattern.

Kelly WG et al. (1994) Worm Breeder's Gazette "A Defined Set of Lethal Mutations at the Right End of the LGII Cluster."

Fire A, Kelly WG

[Worm Breeder's Gazette, 1994]

A Defined Set of Lethal Mutations at the Right End of the LGII Cluster. William G. Kelly and Andrew Fire, Dept. Embryology, Carnegie Institution of Washington, Baltimore, MD. The cey-l gene encodes a DNA binding protein which exhibits specific binding to two sites in the internal enhancer of unc-54 1. cey-l is expressed in oocytes and ubiquitously in the early embryo, but later becomes restricted to mesoderm2. This suggests CEY-1 could play a role in specifying mesodermal patterns of gene expression. To elucidate the role of cey-l in normal development, we have pursued two approaches toward isolating mutations: 1) An EMS screen for visible and lethal mutations in the region of LG II where cey-l has been physically mapped; and 2) Tcl-based screens (i.e., sending off primers to Ronald Plasterk and Marianne de Vroomen). This article summarizes the current state of the EMS screens. The screens were carried out primarily by cloning wild type Fl progeny of [unc 4/mnCI males] X [mutagenized unc-4 hermaphrodites]. In these screens, 840 mnCl balanced visible and lethal mutations were recovered from 8954 mutagenized chromosomes. These mutants were then tested for complementation with mnDf90. Of the 840 candidates tested, 84 failed complementation with mnDf90; these were then tested against mnDf87 and mnDp7. In total, 7 zygotic lethal complementation groups, but no visible mutations, were found to lie within an mnDF9OimnDf77 overlap that lies outside of mnDp7.

Frederick A. Partridge et al. (2006) European Worm Meeting "The Glycosyltransferase BUS-8 is Essential for Epidermal Morphogenesis"

Jonathan Hodgkin, Frederick A. Partridge, Adam W. Tearle, Maria J. Gravato-Nobre, William R. Schafer

[European Worm Meeting, 2006]

Frederick A. Partridge1, Adam W. Tearle2, Maria J. Gravato-Nobre1, William R. Schafer2 and Jonathan Hodgkin1. In C. elegans the epidermis is a simple epithelium. It is derived from a sheet of cells on the dorsal side of the embryo that spread to enclose the ventral side prior to elongation. The epidermis is then covered by the cuticle, an extracellular structure. We independently isolated alleles of bus-8 in screens for mutants resistant to infection by Microbacterium nematophilum and for nicotine hypersensitivity. Further alleles were obtained from a non-complementation screen, and a deletion (putative null) allele was provided by Shohei Mitani. bus-8(null) animals arrest during embryogenesis. We have shown that this is due to a defect in ventral enclosure, leading to extrusion of the body contents through the anterior of the ventral side during early elongation. This is reminiscent of mutations in the cadherin hmr-1. Weaker alleles of bus-8 show a variety of larval defects, including hypersensitivity to a variety of drugs. We have examined the structure of the cuticle and epidermis by electron microscopy. The epidermis is strikingly disordered. We also see abnormalities in the surface coat and cuticle. We propose that, due to their abnormalities in epidermal morphogenesis, bus-8 mutants are more permeable to small molecules. We have cloned bus-8. It encodes a putative glycosyltransferase. This suggests that glycosylation may have a role in mediating cadherin-based adhesion. We will discuss our progress at relating the molecular identity of bus-8 to its roles during development.