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Dirks, R.P., Pijnenburg, D., Kerkhof, E., Yebra - Pimental, E., Louter - van de Haar, J., Woollard, A., Whale, G.F., Pears, C., Spaink, H.P., Racz, P.I., Pieters, R., Maxwell, S., Ruijtenbeek, R., Rooseboom, M., Smulders, C., Currie, R., Warren, E.
[
International Worm Meeting,
2017]
There is an increasing requirement for innovative toxicity test systems that are translational to humans yet allow reduction, refinement and replacement (3Rs) of animal use. It has been shown that "stand alone test models" are not sufficient for hazard assessment and combinatorial testing with multiple 3R models (especially for developmental and reproductive toxicology (DART)) is required to improve potential hazard identification. We introduce a combinatorial strategy using zebrafish (Danio rerio) larvae, nematodes (Caenorhabditis elegans) and social amoebae (Dictyostelium discoideum) as an innovative toxicity test system to enable identification of adverse outcome pathways (AOP) for human hazard identification and characterization. The selected test systems allow high-throughput screening and facilitate rapid, reproducible testing of compounds both on an organismal phenotypic level as well as on a molecular level (transcriptomics and activity profiling of kinases). We have tested 42 DART positive compounds and each of the species showed high sensitivity and specificity levels indicating high predictive power. Of 42 DART positives only 1 compound was missed by all three test systems. Nine compounds were used in a detailed molecular proof of principle study to investigate molecular effects of DART chemicals in the test systems. Overlapping molecular responses of DART compounds could be identified within species amongst the selected set of DART compounds and also across species. Toxicogenomic profiling and hazard assessment revealed that the individual species are promising predictors for DART with clear added value.
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[
Biochemistry,
1987]
The major intestinal esterase from the nematode Caenorhabditis elegans has been purified to essential homogeneity. Starting from whole worms, the overall purification is 9000-fold with a 10% recovery of activity. The esterase is a single polypeptide chain of Mr 60,000 and is stoichiometrically inhibited by organophosphates. Substrate preferences and inhibition patterns classify the enzyme as a carboxylesterase (EC 3.1.1.1), but the physiological function is unknown. The sequence of 13 amino acid residues at the esterase N- terminus has been determined. This partial sequence shows a surprisingly high degree of similarity to the N-terminal sequence of two carboxylesterases recently isolated from Drosophila mojavensis [Pen, J., van Beeumen, J., & Beintema, J. J. (1986) Biochem. J. 238, 691-699].
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[
International C. elegans Meeting,
1995]
The strain Bristol N2 has no endogenous Tc3 transposition activity, but forced expression of Tc3 transposase results in somatic transposition of endogenous Tc3 elements as well as Tc3 elements located on a transgene (Van Luenen et al. 1993 EMBO J. 12:2513-2520). This provides us with an assay for the requirements of Tc3 transposition in vivo.
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[
Hermann, Editeurs des Sciences et des Arts. Paris, France.,
2002]
L'espce Caenorhabditis elegans fut dcrite en 1900 Alger par E. Maupas, qui s'intressait son mode de reproduction hermaphrodite. Plus tard, vers le milieu du vingtime sicle, V. Nigon et ses collaboratuers Lyon tudirent les reorganizations cellulaires accompagnant la fecundation et les premiers clivages. J. Brun isola les preiers mutants morpholgiques.
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[
International Worm Meeting,
2009]
Interactions between proteins are a key component of most or all biological processes. A key challenge in biology is to generate comprehensive and accurate maps (interactomes) of all possible protein interactions in an organism. This will require iterative rounds of interaction mapping using complementary technologies, as well as technological improvements to the approaches used. For example, we recently developed a novel yeast two-hybrid approach that adds a new level of detail to interaction maps by defining interaction domains(1). Currently, I am working to generate an interaction map of proteins involved in controlling cell polarity in C. elegans to improve our understanding of the molecular mechanisms that establish and maintain cell polarity in multicellular organisms. I will combine two fundamentally different interaction mapping techniques: the yeast two-hybrid system (Y2H) and affinity purification/mass spectrometry (AP/MS). This will provide more detail by identifying both direct interactions between pairs of proteins by Y2H, and the composition of protein complexes by AP/MS. Moreover, interactions missed by one technology may be detected by the other, leading to a more complete interaction map. I will integrate the physical interactions with phenotypic characterizations. To this end I will systematically characterize the interaction network in vivo using two distinct models of polarity: asymmetric division of the one-cell embryo, and stem-cell-like divisions of a multicellular epithelium (in collaboration with M. Wildwater and S. van den Heuvel). M. Boxem, Z. Maliga, N. Klitgord, N. Li, I. Lemmens, M. Mana, L. de Lichtervelde, J. D. Mul, D. van de Peut, M. Devos, N. Simonis, M. A. Yildirim, M. Cokol, H. L. Kao, A. S. de Smet, H. Wang, A. L. Schlaitz, T. Hao, S. Milstein, C. Fan, M. Tipsword, K. Drew, M. Galli, K. Rhrissorrakrai, D. Drechsel, D. Koller, F. P. Roth, L. M. Iakoucheva, A. K. Dunker, R. Bonneau, K. C. Gunsalus, D. E. Hill, F. Piano, J. Tavernier, S. van den Heuvel, A. A. Hyman, and M. Vidal, A protein domain-based interactome network for C. elegans early embryogenesis. Cell, 2008. 134(3): p. 534-545. .
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[
Worm Breeder's Gazette,
1994]
mab-3 YAC rescue David Zarkower, Mario de Bono, and Jonathan Hodgkin MRC Laboratory of Molecular Biology, Cambridge, England
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[
Int Microbiol,
2019]
Considering the emergence of multidrug resistance (MDR) in prevalent human pathogen, Mycobacterium tuberculosis (MTB), there is parallel spurt in development of novel strategies aimed to disrupt MDR. The cell envelope of MTB comprises a wealth of lipid moieties contributing towards long-term survival of pathogen that could be exploited as efficient antitubercular target owing to advancements made in mass spectrometry-based lipidomics technology. This study aimed to utilize the lipidomics approach to unveil several lipid associated changes in response to natural antimycobacterial compound vanillin (Van) in Mycobacterium smegmatis, a surrogate for MTB. Lipidomic analyses revealed that that Van alters the composition of fatty acid (FA), glycerolipid (GL), glycerophospholipid (GP), and saccharolipids (SL). Furthermore, Van leads to potentiation of ampicillin and displayed additive effect. The differential expressions of various lipid biosynthetic pathway genes by RT-PCR corroborated with the lipidomics data. Lastly, we demonstrated enhanced survival of Mycobacterium-infected Caenorhabditis elegans model in presence of Van. Thus, lipidomics approach provided detailed insight into mechanisms of membrane disruption by Van in Mycobacterium smegmatis. Our work offers the basis of further understanding the regulation of lipid homeostasis in MTB so that better therapeutic targets could be identified to combat MDR.
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[
Aging Cell,
2002]
The papers by Van Voorhies in Free Radical Biology & Medicine (33, 587-596, 2002) and in this journal claim that the major longevity-extending mutations in C. elegans essentially act by reducing metabolic rate as predicted by the rate-of-living theory, and do not alter any metabolically independent mechanism specific to aging. In contrast, we found no evidence of a reduction in metabolic rate in these mutants using different experimental approaches. Now, Van Voorhies challenges the accuracy of our experimental results.
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[
Mol Cell,
2009]
Three recent papers (Gu et al., 2009; Claycomb et al., 2009; van Wolfswinkel et al., 2009) provide evidence that links a new class of small RNAs and Argonaute-associated complexes to centromere function and genome surveillance.
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[
Vet Parasitol,
2008]
Strongyloides sp. (Nematoda) are very wide spread small intestinal parasites of vertebrates that can form a facultative free-living generation. Most authors considered all Strongyloides of farm ruminants to belong to the same species, namely Strongyloides papillosus (Wedl, 1856). Here we show that, at least in southern Germany, the predominant Strongyloides found in cattle and the Strongyloides found in sheep belong to separate, genetically isolated populations. While we did find mixed infections in cattle, one form clearly dominated. This variety, in turn, was never found in sheep, indicating that the two forms have different host preferences. We also present molecular tools for distinguishing the two varieties, and an analysis of their phylogenetic relationship with the human parasite Strongyloides stercoralis and the major laboratory model species Strongyloides ratti. Based on our findings we propose that Strongyloides from sheep and the predominant Strongyloides from cattle should be considered separate species as it had already been proposed by [Brumpt, E., 1921. Recherches sur le determinisme des sexes et de l''evolution des Anguillules parasites (Strongyloides). Comptes rendu hebdomadaires des seances et memoires de la Societe de Biologie et de ses filiales 85, 149-152], but was largely ignored by later authors. For nomenclature, we follow [Brumpt, E., 1921. Recherches sur le determinisme des sexes et de l''evolution des Anguillules parasites (Strongyloides). Comptes rendu hebdomadaires des seances et memoires de la Societe de Biologie et de ses filiales 85, 149-152] and use the name S. papillosus for the Strongyloides of sheep and the name Strongyloides vituli for the predominant Strongyloides of cattle.