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[
International Worm Meeting,
2011]
The FoxO transcription factor DAF-16 regulates a wide range of organismal functions: it is involved in C. elegans development and reproduction, in stress response and life span regulation. Association of DAF-16 with diverse binding partners might be crucial for mediating these heterogeneous functions (1-4). To identify DAF-16 regulators we established a biochemical approach for the purification of DAF-16 associated proteins. DAF-16 was fused to various epitop-tags. On the basis of a reporter assay it was analyzed whether the tagged DAF-16 versions were transcriptionally active and a dauer assay was used to test for their physiological activity in worms. A functional tagged DAF-16 variant was used for the generation of transgenic worms. DAF-16 protein complexes were isolated by tandem affinity purification and potential DAF-16 binding partners were identified by tandem mass-spectrometry (MudPIT). In an additional, reporter based screen DAF-16 co-regulators are currently validated and their potential roles in dauer formation, stress resistance and longevity are currently being pursued. We will discuss their identity and potential functions in insulin/IGF-1 signaling.
(1): Essers, MA. et al., Science. 2005; 308(5725): 1181-1184
(2): Wolff, S. et al., Cell. 2006; 124(5): 1039-1053
(3): Berdichevsky, A. et al., Cell. 2006; 125(6): 1165-1177
(4): Li, J. et al., PLoS Biol. 2008; 6(9): 1870-1886
This work was supported in part by the Austrian Science Fund (FWF, grant J2734), by a grant from NIH, and by the Glenn Center for Aging Research.
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[
Worm Breeder's Gazette,
1994]
Some notes on mapping contigs using molecular analysis of deficiencies Frans Tax and Jim Thomas, Dept. of Genetics, University of Washington, Seattle WA 98195
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[
International C. elegans Meeting,
1999]
In order to characterize the neural circuit of C. elagans, we construct a simple model by making use of the data table completed recently by Oshio et al . [1]. We assume that the signal of a neuron is calculated by the product of the signals from the neighboring neurons, and we investigate the touch sensitivity to continuous stimuli described by sinusoidal functions as defined in the rage from 0.0 to 1.0. We calculate the responses of the motor neurons by changing the frequencies of the stimuli. In our calculations, we change only the frequency w PLM for the input signal to the sensory neuron PLM, while the frequency for the other sensory neurons ALM, AVM and PVM is fixed to be a same value w 0 . We show that the output signals from the motor neurons A and B oscillate in time. We measure the minima of the oscillation for each w PLM value. The plot of the minima versus w PLM shows different hehaviors for the case of the neuron A and B. As for the signals from the neuron A, the values of the minima are widely distributed between 0.0 and 1.0 for all w PLM . As for the signals from the neuron B, on the other hand, the features are different for different w PLM values. (a) In the high frequency region of w PLM / w 0 0.4, the oscillation is simple harmonic and there exists only one minimum value (I min = 0.0). (b) As w PLM / w 0 is decreased, another minimum appears at a certain frequency, and the bifurcation takes place discontinuously. This behavior is different from usual continuous bifurcation observed in nonlinear systems. After a few discontinuous branching occur, signals with five periods can be seen in the intermediate frequency region of 0.3 w PLM / w 0 w PLM / w 0 [1] K. Oshio et al. ; C. elegans synaptic connectivity data'', Technical Report, CCEP, Keio Future No.1 (1998).
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Zhao T, Oswald NW, Li Y, Lin R, Wang C, Jaramillo J, Zhou A, McMillan EA, Douglas PM, MacMillan JB, Huang G, Luo M, Gao J, Mendiratta S, Lin Z, Wang Z, Niederstrasser H, Posner BA, Brekken RA, White MA
[
Nat Commun,
2018]
The originally published version of this Article contained an error in the spelling of the author Nathaniel W. Oswald, which was incorrectly given as Nathaniel W. Olswald. This has now been corrected inboth the PDF and HTML versions of the Article.
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[
Worm Breeder's Gazette,
1994]
lin-36, a Class B Synthetic Multivulva Gene, Encodes a Novel Protein Jeffrey H. Thomas and H. Robert Horvitz, HHMI, Dept. Biology, MIT, Cambridge, MA 02139, USA
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[
Parasite Immunol,
1985]
The susceptibility of congenitally anemic, and mast cell deficient W/Wv mice to infection with Strongyloides ratti was examined. After a primary infection, W/Wv mice showed greater and more persistent peak larval counts than did normal littermates. Worm expulsion was also slower in W/Wv mice than in +/+ mice. Furthermore, difference in susceptibility was expressed as early as 24 h after infection, suggesting not only that protective mechanisms of the gut but also of the connective tissue were defective in W/Wv mice. Reconstitution with bone marrow or spleen cells from +/+ mice was effective in restoring the protective response in W/Wv mice, whereas thymocytes or mesenteric lymph nodes had no effect. Both connective tissue and mucosal mast cells were repaired in W/Wv mice after marrow reconstitution and infection. Since relatively long incubation period was required for the expression of such reconstituting activities, bone marrow cells seem to contain precursor cells of the effector and/or regulator cells.
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[
Int J Parasitol,
2004]
Wolbachia pipientis is a bacterial endosymbiont associated with arthropods and filarial nematodes. In filarial nematodes, W. pipientis has been shown to play an important role in the biology of the host and in the immuno-pathology of filariasis. Several species of filariae, including the most important parasites of humans and animals (e.g. Onchocerca volvulus, Wuchereria bancrofti and Dirofilaria immitis) have been shown to harbour these bacteria. Other filarial species, including an important rodent species (Acanthocheilonema viteae), which has been used as a model for the study of filariasis, do not appear to harbour these symbionts. There are still several open questions about the distribution of W. pipientis in filarial nematodes. Firstly the number of species examined is still limited. Secondly, it is not clear whether the absence of W. pipientis in negative species could represent an ancestral characteristic or the result of a secondary loss. Thirdly, several aspects of the phylogeny of filarial nematodes are still unclear and it is thus difficult to overlay the presence/absence of W. pipientis on a tree representing filarial evolution. Here we present the results of a PCR screening for W. pipientis in 16 species of filariae and related nematodes, representing different families/subfamilies. Evidence for the presence of W. pipientis is reported for five species examined for the first time (representing the genera Litomosoides, Litomosa and Dipetalonema); original results on the absence of this bacterium are reported for nine species; for the remaining two species, we have confirmed the absence of W. pipientis recently reported by other authors. In the positive species, the infecting W. pipientis bacteria have been identified through 16S rDNA gene sequence analysis. In addition to the screening for W. pipientis in 16 species, we have generated phylogenetic reconstructions based on mitochondrial gene sequences (12S rDNA; COI), including a total of 28 filarial species and related spirurid nematodes. The mapping of the presence/absence of W. pipientis on the trees generated indicates that these bacteria have possibly been lost during evolution along some lineages of filarial nematodes.
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[
Worm Breeder's Gazette,
1993]
ceh 6 expression and generation of a knock-out Thomas Burglin, Ron Plasterk*, Gary Ruvkun Dept. of Molecular Biology, Wellman 8, Massachusetts General Hospital, Boston, MA, 02114, USA, and *Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, The Netherlands.
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[
Worm Breeder's Gazette,
1981]
I have made two modifications in the Ficoll method I originally described in WBG, vol. 3, #2. First, all Ficoll solutions are made 0. 1 M in NaCl to avoid shocking osmoticalIy sensitive worms like
unc-29(
e1072). Second, after sedimenting worms through 15% w/w Ficoll 400 ( 15', 300 x g), the worms are diluted with an equal volume of 0.1 M NaCl and floated on 35% w/w Ficoll (15', 300 x g) before washing 2x with 0.1 M NaCl. The Ficoll sedimentation removes dead or degenerated worms, cuticles, bacteria. The flotation removes crystalline debris sometimes occurring in worm cultures. We also find that special care to pipette out the last residue of bacterial medium (e.g. 3XD) before resuspending bacteria for worm growth is most conducive to obtaining uncontaminated worms.
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[
Pak J Pharm Sci,
2018]
We investigated the cellulase-assisted extraction and anti-ultraviolet activity of water-soluble polysaccharides from the root of Flammulina velutipes on Caenorhabditis elegans. A Box-Behnken design experiment with three factors and three levels, including enzymolysis temperature, microwave time, and microwave power, was designed on the basis of the results of single-factor experiments. For improving the polysaccharide yield of F. velutipes root, the following optimal extraction conditions were used: 52.67C enzymolysis temperature, 80s microwave time, and 144 W microwave power. Under optimal conditions, the actual measured value of the yield was 2.01% (w/w) and the predicted value was 2.06% (w/w). One fraction (FRP-2) was isolated and purified, and its characteristics were analyzed. The average mean molecular weight of FRP-2 was measured to be 2.60x10<sup>5</sup> Da, and its monosaccharide composition is mainly glucose. The sugar units are present both in the -configuration and -configuration. Moreover, FRP-2 exhibited certain anti-ultraviolet activity to C. elegans when the polysaccharide concentration ranged between 0.05mg/mL and 0.20mg/mL.