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[
G3 (Bethesda),
2022]
Isolation of copy number variations and chromosomal duplications at high frequency in the laboratory suggested that Caenorhabditis elegans tolerates increased gene dosage. Here we addressed if a general dosage compensation mechanism acts at the level of mRNA expression in C. elegans. We characterized gene dosage and mRNA expression in three chromosomal duplications and a fosmid integration strain using DNA-seq and mRNA-seq. Our results show that on average, increased gene dosage leads to increased mRNA expression, pointing to a lack of genome-wide dosage compensation. Different genes within the same chromosomal duplication show variable levels of mRNA increase, suggesting feedback regulation of individual genes. Somatic dosage compensation and germline repression reduce the level of mRNA increase from X chromosomal duplications. Together, our results show a lack of genome-wide dosage compensation mechanism acting at the mRNA level in C. elegans and highlight the role of epigenetic and individual gene regulation contributing to the varied consequences of increased gene dosage.
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[
International Worm Meeting,
2019]
Condensins are conserved ring-shaped protein complexes that are essential for development and are involved in organization of chromosomes in animals. In C. elegans, there are three types of condensins: condensin I, II, and DC. Condensin DC interacts with other proteins to make up the dosage compensation complex (DCC). DCC binds to the two X chromosomes and represses both in XX hermaphrodites by half to match the expression of the single X in XO males. The DCC binds to short genomic recruitment elements on the X (rex) from which they spread to promoters and enhancers. DCC regulates X chromosome organization in part by mediating long-range 3D interactions between rex sites. To understand the mechanisms that confer specificity to the rex interactions, we applied 4C-seq analyses in C. elegans. Next, I am using CRISPR/Cas9 to ectopically insert a rex element in two orientations. I will conduct ChIP qPCR to determine if rex sequence orientation is important for DCC recruitment and then perform comparative 4C-seq analysis to determine the dependence of 3D interactions on sequence, position, and orientation of the rex element. This information will be important for understanding the mechanisms behind condensin-mediated organization of chromosome structure.
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[
Mar Drugs,
2019]
Several known sesquiterpenoid quinones and quinols (<b>1</b>-<b>9</b>), and kauamide (<b>10</b>), a new polyketide-peptide containing an 11-membered heterocycle, were isolated from the extracts of the Hawaiian marine sponge <i>Dactylospongia</i><i>elegans</i>. The planar structure of <b>10</b> was determined from spectroscopic analyses, and its relative and absolute configurations were established from density functional theory (DFT) calculations of the GIAO NMR shielding tensors, and advanced Marfey's analysis of the <i>N</i>-MeLeu residue, respectively. Compounds <b>1</b> and <b>3</b> showed moderate inhibition of -secretase 1 (BACE1), whereas <b>1</b>-<b>9</b> exhibited moderate to potent inhibition of growth of human glioma (U251) cells. Compounds <b>1</b>-<b>2</b> and <b>4</b>-<b>7</b> were also active against human pancreatic carcinoma (Panc-1) cells.
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[
International Worm Meeting,
2019]
Unlike most eukaryotes, which have two condensins for compacting DNA during mitosis/meiosis, Caenorhabditis elegans have evolved a third version of condensin called dosage compensation condensin (condensin DC). Condensin DC shares 4/5 subunits with condensin I, which is largely cytoplasmic and associates with chromosomes after nuclear envelope breakdown to accomplish condensation before segregation. Unlike condensin I, condensin DC remains bound on X chromosomes in hermaphrodite (XX) throughout interphase to repress the expression from each X chromosome by roughly half, thereby equalizing X expression between hermaphrodites (XX) and males (XO). We are interested in how these condensins have evolved to participate in these two distinct cellular processes. Structurally, condensin DC differs from condensin I by a single subunit DPY-27, a variant of SMC4. Despite minor differences, the main functional motifs of SMC proteins, including SMC-4 and DPY-27, are highly conserved throughout evolution. To study how condensins have evolved in C. elegans, we have generated lines with heat-shock inducible and GFP tagged SMC-4 and DPY-27 with mutations in highly conserved motifs and compared our microscopy data with those of other organisms with the same conserved mutations. We have preliminary data suggesting that, despite the strong structural conservation among SMC proteins in various organisms, the functional consequence of mutating the same conserved motif is different in C. elegans. We observed that the mutation in Walk-B motif of the ATPase domain, which slows down the rate of ATP hydrolysis, in SMC-4 and DPY-27, resulted in their complete loss of binding to DNA. In contrast, others have observed that the same mutations in SMC proteins in Xenopus and chicken cells did not disrupt their ability to bind DNA but resulted in their failure to condense DNA. We conclude that the need for a third version of condensin puts a unique evolutionary constraint on the SMC proteins of C. elegans.
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[
J Nat Prod,
2019]
To explore the chemical diversity of metabolites from new species of Dothideomycetes, the ex-type strain of <i>Sparticola junci</i> was investigated. Seven highly oxygenated and functionalized spirodioxynaphthalene natural products incorporating carboxyalkylidene-cyclopentanoid (<b>1</b>-<b>4</b>), carboxyl-functionalized oxabicyclo[3.3.0]octane (<b>5</b>-<b>6</b>), and annelated 2-cyclopentenone/-lactone (<b>7</b>) units, sparticolins A-G, were isolated from submerged cultures of the fungus. Their chemical structures including their relative (and absolute) configurations were established through spectroscopic and X-ray crystallographic analyses. Sparticolin B (<b>2</b>) exhibited inhibitory activity against the Gram-positive bacteria <i>Bacillus subtilis</i>, <i>Micrococcus luteus</i>, and <i>Staphylococcus aureus</i>, while sparticolin G (<b>7</b>) showed antifungal activities against <i>Schizosaccharomyces pombe</i> and <i>Mucor hiemalis</i>. All other sparticolins were only weakly active against <i>S. aureus</i> and also showed weak activities against the nematode <i>Caenorhabditis elegans</i>. Compounds <b>2</b> and <b>7</b> also showed moderate cytotoxic activities against seven mammalian cell lines.
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[
Biosci Biotechnol Biochem,
2019]
The nematocidal activities of the fatty acid esters of d-allose were examined using the larvae of <i>C. elegans</i>. Among the fatty acid esters, 6-<i>O</i>-octanoyl-d-allose (<b>3</b>) showed significant activity. 6-<i>O</i>-octanoyl-d-glucose (<b>5</b>) showed no activity, indicating that the D-allose moiety is essential for the nematocidal activity of <b>3</b>. A nonhydrolyzable alkoxy analog 6-<i>O</i>-octyl-d-allose (<b>6</b>) also showed activity equivalent to that of <b>3</b>.
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[
Biomolecules,
2021]
<i>Ozoroa insignis</i> Del. is an ethnobotanical plant widely used in traditional medicine for various ailments, including schistosomiasis, tapeworm, and hookworm infections. From the so far not investigated fruits of <i>Ozoroa insignis</i>, the anthelmintic principles could be isolated through bioassay-guided isolation using <i>Caenorhabditis elegans</i> and identified by NMR spectroscopic analysis and mass spectrometric studies. Isolated 6-[8(<i>Z</i>)-pentadecenyl] anacardic (<b>1</b>), 6-[10(<i>Z</i>)-heptadecenyl] anacardic acid (<b>2</b>), and 3-[7(<i>Z</i>)-pentadecenyl] phenol (<b>3</b>) were evaluated against the 5 parasitic organisms <i>Schistosoma mansoni</i> (adult and newly transformed schistosomula), <i>Strongyloides ratti</i>, <i>Heligmosomoides polygyrus</i>, <i>Necator americanus</i>, and <i>Ancylostoma ceylanicum</i>, which mainly infect humans and other mammals. Compounds <b>1</b>-<b>3</b> showed good activity against <i>Schistosoma mansoni</i>, with compound <b>1</b> showing the best activity against newly transformed schistosomula with 50% activity at 1M. The isolated compounds were also evaluated for their cytotoxic properties against PC-3 (human prostate adenocarcinoma) and HT-29 (human colorectal adenocarcinoma) cell lines, whereby compounds <b>2</b> and <b>3</b> showed antiproliferative activity in both cancer cell lines, while compound <b>1</b> exhibited antiproliferative activity only on PC-3 cells. With an IC<sub>50</sub> value of 43.2 M, compound <b>3</b> was found to be the most active of the 3 investigated compounds.
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Eifler-Lima VL, Garcia SC, Sauer E, Figueiro F, das Neves GM, Rockenbach L, Kagami LP, Munhoz T, Oliveira Batasttini AM, Goethel G, Goncalves IL
[
Future Med Chem,
2020]
<b>Background:</b> Dihydropyrimidin-2-thiones (DHPMs) are a class of heterocyclic compound which have been intensively investigated mainly due to their anticancer activity as kinesin Eg5 inhibitors. <b>Materials & methods:</b> A library of N1 aryl substituted DHPMs were tested against glioma and bladder cancer cell lines. Quantitative structure-activity relationship (QSAR) investigation was performed in order to identify key elements of DHPMs linked with their antiproliferative effect. The toxicity of most active compounds was investigated using <i>Caenorhabditis elegans</i> as the model. <b>Results & conclusion:</b> DHPMs <b>9</b>, <b>13</b> and <b>17</b> have been identified as having improved activity against glioma and bladder cell lines as compared with monastrol. Flow cytometry investigations showed that the new compounds induce cell cycle arrest in phase G<sub>2</sub>/M and cell death by apoptosis. In addition, compound <b>13</b>was able to modulate the reactive oxygen species production <i>in vivo</i> in <i>C. elegans</i>. The biphenyl dihydropyrimidinthiones provided a safety profile in <i>C. elegans</i>.
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[
Nat Prod Res,
2020]
A new highly oxygenated germacranolide, carcerlane A (<b>1</b>), together with four known highly oxygenated germacranolides (<b>2</b>-<b>5</b>), was isolated from an ethanol extract of the whole plant of <i>Carpesium nepalense</i> var. <i>lanatum</i> (C.B.Clarke) Kitam. The structures were determined by HRESIMS and extensive analysis of their spectroscopic data including IR, 1D and 2D NMR spectra. To our best knowledge, it was the first time to report the phytochemical investigation on this plant. The anti-Alzheimer's disease (AD) activities of <b>1</b>-<b>5</b> were evaluated using <i>Caenorhabditis elegans</i> AD pathological model. All the tested compounds showed that they have the anti-AD bioactivities of delaying worms paralysis.
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[
Parasitology,
1991]
Pine wilt is the most serious disease of native pines in Japan and potentially the most important nematode disease of conifers in the world. The pinewood nematode Bursaphelenchus xylophilus was found to be the casual agent. Difficulties arose with respect to the precise identity of some isolates of B. xylophilus and of similar species B. mucronatus and B. fraudulentus. Restriction enzyme analyses of repetitive DNA revealed bands specific for the species B. xylophilus, B. mucronatuus and B. fraudulentus. Hybridization patterns obtained with
unc-22 gene of C. elegans, clearly identified B. xylophilus, B. mucronatus and B. fraudulentus as well as the different geographic isolates of these species. Furthermore, it is possible to define the phylogenetic relationships between the different populations constituting the 'pine wood