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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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[
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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[
Curr Med Mycol,
2020]
Background and Purpose: . Materials and Methods: nematode model. Results: infection. The results also confirmed negligible hemolytic activity on erythrocytes. Conclusion: As the findings of the present study indicated, Van is a persuasive natural compound that warrants further attention to exploit its anticandidal potential.
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[
J Neurosci,
2003]
Thermotactic behavior in Caenorhabditis elegans is sensitive to both a worm's ambient temperature (T-amb) and its memory of the temperature of its cultivation (T-cult). The AFD neuron is part of a neural circuit that underlies thermotactic behavior. By monitoring the fluorescence of pH-sensitive green fluorescent protein localized to synaptic vesicles, we measured the rate of the synaptic release of AFD in worms cultivated at temperatures between 15 and 25degreesC, and subjected to fixed, ambient temperatures in the same range. We found that the rate of AFD synaptic release is high if either T-amb > T-cult or T-amb > T-cult, but AFD synaptic release is low if T-amb congruent to T-cult. This suggests that AFD encodes a direct comparison between T-amb and T-cult.
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[
Genomics,
1995]
Recently, a novel family of genes with a region of homology to the mouse T locus, which is known to play a crucial, and conserved, role in vertebrate development, has been discovered. The region of homology has been named the T-box. The T-box domain of the prototypical T locus product is associated with sequence-specific DNA binding activity. In this report, we have characterized four members of the T-box gene family from the nematode Caenorhabditis elegans. All lie in close proximity to each other in the middle of chromosome III. Homology analysis among all completely sequenced T-box products indicates a larger size for the conserved T-box domain (166 to 203 residues) than previously reported. Phylogenetic analysis suggests that one C. elegans T-box gene may be a direct ortholog of the mouse Tbx2 and Drosophila omb genes. The accumulated data demonstrate the ancient nature of the T-box gene family and suggest the existence of at least three separate T-box-containing genes in a common early metazoan ancestor to nematodes and vertebrates.
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[
Development,
2023]
Sequential rosettes are a type of collective cell behavior recently discovered in the C. elegans embryo that mediates directional cell migration through sequential formation and resolution of multicellular rosettes involving the migrating cell and its neighboring cells along the way. Here we show that a Planar Cell Polarity (PCP)-based polarity scheme regulates sequential rosettes, which is distinct from the known mode of PCP regulation in multicellular rosettes during the process of convergent extension. Specifically, non-muscle myosin (NMY) localization and edge contraction are perpendicular to that of Van Gogh as opposed to colocalizing with Van Gogh. Further analyses suggest a two-component polarity scheme: one being the canonical PCP pathway with MIG-1/Frizzled and VANG-1/Van Gogh localized to the vertical edges, the other being MIG-1/Frizzled and NMY-2 localized to the midline/contracting edges. The NMY-2 localization and contraction of the midline edges are also required LAT-1/Latrophilin, an adhesion G protein-coupled receptor which has not been shown to regulate multicellular rosettes. Our results establish a distinct mode of PCP-mediated cell intercalation and shed light on the versatile nature of PCP pathway.
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[
Glycobiology,
2006]
The common O-glycan core structure in animal glycoproteins is the core 1 disaccharide Galbeta1-3GalNAcalpha1-Ser/Thr, which is generated by addition of Gal to GalNAcalpha1-Ser/Thr by core 1 UDP-Gal:GalNAcalpha1-Ser/Thr beta1,3-galactosyltransferase (core 1 beta3-Gal-T or T-synthase, EC2.4.1.122)(2). Although O-glycans play important roles in vertebrates, much remains to be learned from model organisms such as the free-living nematode Caenorhabditis elegans, which offer many advantages in exploring O-glycan structure/function. Here we report the cloning and enzymatic characterization of T-synthase from C. elegans (Ce-T-synthase). A putative C. elegans gene for T-synthase, C38H2.2, was identified in GenBank by a BlastP search using the human T-synthase protein sequence. The full-length cDNA for Ce-T-synthase, which was generated by PCR using a C. elegans cDNA library as the template, contains 1,170 bp including the stop TAA. The cDNA encodes a protein of 389 amino acids with typical type-II membrane topology and a remarkable 42.7% identity to the human T-synthase. Ce-T-synthase has 7 Cys residues in the lumenal domain including 6 conserved Cys residues in all of the orthologs. The Ce-T-synthase has 4 potential N-glycosylation sequons, whereas the mammalian orthologs lack N-glycosylation sequons. Only one gene for Ce-T-synthase was identified in the genome-wide search and it contains 8 exons. Promoter analysis of the Ce-T-synthase using green fluorescent protein constructs show that the gene is expressed at all developmental stages and appears to be in all cells. Unexpectedly, only minimal activity was recovered in the recombinant, soluble Ce-T-synthase secreted from a wide variety of mammalian cell lines, whereas robust enzyme activity was recovered in the soluble Ce-T-synthase expressed in Hi-5 insect cells. Vertebrate T-synthase requires the molecular chaperone Cosmc, but our results show that Ce-T-synthase does not require Cosmc, and might require invertebrate-specific factors for formation of the optimally active enzyme. These results show that the Ce-T-synthase is a functional ortholog to the human T-synthase in generating core 1 O-glycans and opens new avenues to explore O-glycan function in this model organism.
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[
Methods Mol Biol,
2012]
This chapter was written as a guide to using the long-amplicon quantitative PCR (QPCR) assay for the measurement of DNA damage in mammalian as well as nonmammalian species such as Caenorhabditis elegans (nematodes), Drosophila melanogaster (fruit flies), and two species of fish (Fundulus heteroclitus and Danio rerio). Since its development in the early 1990s (Kalinowski et al., Nucleic Acids Res 20:3485-3494, 1992; Salazar and Van Houten, Mutat Res 385:139-149, 1997; Yakes and Van Houten, Proc Natl Acad Sci USA 94:514-519, 1997), the QPCR assay has been widely used to measure DNA damage and repair kinetics in nuclear and mitochondrial genomes after genotoxin exposure (Yakes and Van Houten, Proc Natl Acad Sci USA 94:514-519, 1997; Santos et al., J Biol Chem 278:1728-1734, 2003; Mandavilli et al., Mol Brain Res 133:215-223, 2005). One of the main strengths of the assay is that the labor-intensive and artifact-generating step of mitochondrial isolation is not needed for the accurate measurement of mitochondrial DNA copy number and damage. Below we present the advantages and limitations of using QPCR to assay DNA damage in animal cells and provide a detailed protocol of the QPCR assay that integrates its usage in newly developed animal systems.
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[
Int J Syst Evol Microbiol,
2007]
A yellow-pigmented, Gram-positive, aerobic, non-motile, non-spore-forming, irregular rod-shaped bacterium (strain TAN 31504(T)) was isolated from the bacteriophagous nematode Caenorhabditis elegans. Based on 16S rRNA gene sequence similarity, DNA G+C content of 69.5 mol%, 2,4-diaminobutyric acid in the cell-wall peptidoglycan, major menaquinone MK-11, abundance of anteiso- and iso-fatty acids, polar lipids diphosphatidylglycerol and phosphatidylglycerol and a number of shared biochemical characteristics, strain TAN 31504(T) was placed in the genus Leucobacter. DNA-DNA hybridization comparisons demonstrated a 91 % DNA-DNA relatedness between strain TAN 31504(T) and Leucobacter chromiireducens LMG 22506(T) indicating that these two strains belong to the same species, when the recommended threshold value of 70 % DNA-DNA relatedness for the definition of a bacterial species by the ad hoc committee on reconciliation of approaches to bacterial systematics is considered. Based on distinct differences in morphology, physiology, chemotaxonomic markers and various biochemical characteristics, it is proposed to split the species L. chromiireducens into two novel subspecies, Leucobacter chromiireducens subsp. chromiireducens subsp. nov. (type strain L-1(T)=CIP 108389(T)=LMG 22506(T)) and Leucobacter chromiireducens subsp. solipictus subsp. nov. (type strain TAN 31504(T)=DSM 18340(T)=ATCC BAA-1336(T)).
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[
Genome,
1997]
The T-box gene family consists of members that share a unique DNA binding domain. The best characterized T-box gene, Brachyury or T, encodes a transcription factor that plays an important role in early vertebrate development. Seven other recently described mouse T-box genes are also expressed during development. In the nematode Caenorhabditis elegans, four T-box genes have been characterized to date. In this study, we describe three new C. elegans T-box genes, named
Ce-tbx-11,
Ce-tbx-12, and
Ce-tbx-17.
Ce-tbx-11 and
Ce-tbx-17 were uncovered through the sequencing efforts of the C. elegans Genome Project.
Ce-tbx-12 was uncovered through degenerate PCR analysis of C. elegans genomic DNA.
Ce-tbx-11 and
Ce-tbx-17 are located in close proximity to the four other previously described T-box genes in the central region of chromosome III. In contrast,
Ce-tbx-12 maps alone to chromosome II. Phylogenetic analysis of all known T-box domain sequences provides evidence of an ancient origin for this gene family.