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[
Kisaengchunghak Chapchi,
1973]
Study of filariasis to determine important factors involved in its ecology was carried out on Che Ju Island for three consecutive years from 1968 to 1970 in seven villages, three coastal villages and four islets remote from the main island. One village which was located in mountainous area far from the coast was surveyed to serve as control area. About 90% of population inhabiting the study area had at least one blood smear during the three-year period; about one third had three blood smears, and a little over one third had two, and the rest only one examination. Animal and mosquito surveys were carried out at the same period. Followings are the results obtained: 1. All human cases but several had microfilariae identical to the description of B. malayi. The several cases who had morphologically different microfilariae from that of B. malayi need further study for definite conclusion. 2. Five persons randomly sampled from Mf positives and bled every two hours demonstrated nocturnal periodicity between 9 p.m. and 3 a.m. 3. Human is considered to be only reservoir host for human filariasis in the area since animal survey and experimental exposure to the infective larvae of human filaria species showed failure to infect animals. 4. Microfilaria rate, microfilaria density, prevalence of elephantiasis varied by area and age with correlation, which indicated cumulative process of the parasite by repeated exposure and development of host immunity to certain extent. 5. Clinical manifestation of filariasis (symptom complex and elephantiasis ) taken from history and inspection was low in its prevalence with range of 0.9% 11.8% of total population. Only 5.2% of 517 Mf positives had the clinical manifestation. 24.8% of 109 persons with clinical manifestation had microfilaria; 42.9% with symptom complex only, 23.1% with both symptoms and elephantiasis, and none with elephantiasis only were microfilaria positive. 6. Ae. togoi was the only species infected with the filaria. Mosquito infection rate by area showed positive correlation to the Mf rate and density of human population; where the Mf rate and density were high, the mosquito infection rate also high.
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[
Bio Protoc,
2017]
Single-molecule RNA fluorescence <i>in situ</i> hybridization (smFISH) is a technique to visualize individual RNA molecules using multiple fluorescently-labeled oligonucleotide probes specific to the target RNA ( Raj <i>et al.</i>, 2008 ; Lee <i>et al.</i>, 2016a ). We adapted this technique to visualize RNAs in the <i>C. elegans</i> whole adult worm or its germline, which enabled simultaneous recording of nascent transcripts at active transcription sites and mature mRNAs in the cytoplasm ( Lee <i>et al.</i>, 2013 and 2016b). Here we describe each step of the smFISH procedure, reagents, and microscope settings optimized for <i>C. elegans</i> extruded gonads.
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[
Dev Cell,
2003]
In a recent paper, Lee and Goldstein develop an explant assay that recapitulates key aspects of gastrulation in C. elegans and permits classical embryological manipulations. The resulting detailed analysis of cell behavior will ultimately extend to broader issues, such as, whether morphogenesis can be described as the sum of single-cell events or if unique phenomena emerge at the multicellular level.
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[
MicroPubl Biol,
2021]
To perturb actomyosin function in the primordial germ line, we first monitored germ line organization in L1-stage animals bearing temperature-sensitive (ts) alleles in genes encoding actomyosin regulators and that were reported to interfere with cytokinesis during embryogenesis (Davies et al. 2014). Previous work demonstrated that the initial stages of germline expansion occur normally in
cyk-4(ts) and
zen-4(ts) animals raised at restrictive temperature from the L1 stage (Lee et al. 2018). We found that primordial germ line organization in
cyk-1(ts),
nmy-2(ts),
cyk-4(ts) or
zen-4(ts) L1 larvae maintained at restrictive temperature for 12h was no different than control (Figure 1A-B). Furthermore, the first primordial germ cell (PGC) division occurred normally upon feeding these animals at restrictive temperature with typical bacterial food (E. coli OP50). As noted previously (Lee et al. 2018), germ line disorganization and sterility were observed in all cases when animals reached adulthood (Figure 1B).
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[
MicroPubl Biol,
2024]
Prenatal stress is hypothesized to contribute to the development of schizophrenia. Lee and colleagues determined that prenatal stress in rats decreases levels of Dpysl2, which is found to be inactivated in schizophrenic patients. UNC-33 , the homolog to Dpysl2 in <i>C. elegans</i> , is important for axonal outgrowth and synapse formation. Herein, we study the effects of antipsychotic drugs on developing <i>C.elegans</i> exposed to stress through high temperatures. Results indicate that the <i>
unc-33</i> promoter was not impacted by antipsychotic drug treatment, but the lifespan was decreased.
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[
Arch Microbiol,
2016]
Enterohemorrhagic E. coli O157:H7 (EHEC) shorten the lifespan of Caenorhabditis elegans compared to avirulent bacteria. Co-feeding EHEC with Enterococcus faecalis Symbioflor() significantly increased the worms' lifespan. The transcriptome of EHEC grown in vitro with or without Symbioflor() was analyzed using RNA-seq. The analysis revealed downregulation of several virulence-associated genes in the presence of Symbioflor(), including virulence key genes (e.g., LEE, flagellum, quorum-sensing). The downregulation of the LEE genes was corroborated by lux-transposon mutants. Upregulated genes included acid response genes, due to a decrease in pH exerted by Symbioflor(). Further genes indicate cellular stress in EHEC (e.g. prophage/mobile elements involved in excision, cell lysis, and cell division inhibition). Thus, the observed protection of C. elegans during an EHEC infection by the probiotic Symbioflor() is suggested to be caused by triggering concomitant transcriptomic changes. To verify the biological relevance of this modulation, exemplary genes found to be influenced by Symbioflor() were knocked out (fliD, espB, Z3136, Z3917, and L7052). The lifespan of nematodes changed when using knock-outs as food source and the effect could be complemented in trans. In summary, Symbioflor() appears to be a protective probiotic in the nematode model.
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[
Mol Microbiol,
2021]
Enterohemorrhagic Escherichia coli (EHEC), an enteropathogen that colonizes in the intestine, causes severe diarrhea and hemorrhagic colitis in humans by the expression of the type III secretion system (T3SS) and Shiga-like toxins (Stxs). However, how EHEC can sense and respond to the changes in the alimentary tract and coordinate the expression of these virulence genes remains elusive. The T3SS-related genes are known to be regulated by the locus of enterocyte effacement (LEE)-encoded regulators, such as Ler, as well as non-LEE-encoded regulators in response to different environmental cues. Herein, we report that OmpR, which participates in the adaptation of E. coli to osmolarity and pH alterations, is required for EHEC infection in Caenorhabditis elegans. OmpR protein was able to directly bind to the promoters of ler and
stx1 (Shiga-like toxin 1) and regulate the expression of T3SS and Stx1, respectively, at the transcriptional level. Moreover, we demonstrated that the expression of ler in EHEC is in response to the intestinal environment and is regulated by OmpR in C. elegans. Taken together, we reveal that OmpR is an important regulator of EHEC which coordinates the expression of virulence factors during gastrointestinal infection in vivo.
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[
Science,
2001]
Caenorhabditis elegans oocytes, like those of most animals, arrest during meiotic prophase. Sperm promote the resumption of meiosis (maturation) and contraction of smooth muscle-like gonadal sheath cells, which are required for ovulation. We show that the major sperm cytoskeletal protein (MSP) is a bipartite signal for oocyte maturation and sheath contraction. MSP also functions in sperm locomotion, playing a role analogous to actin. Thus, during evolution, MSP has acquired extracellular signaling and intracellular cytoskeletal functions for reproduction. Proteins with MSP-like domains are found in plants, fungi, and other animals, suggesting that related signaling functions may exist in other phyla.AD - Department of Cell Biology, Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.FAU - Miller, M AAU - Miller MAFAU - Nguyen, V QAU - Nguyen VQFAU - Lee, M HAU - Lee MHFAU - Kosinski, MAU - Kosinski MFAU - Schedl, TAU - Schedl TFAU - Caprioli, R MAU - Caprioli RMFAU - Greenstein, DAU - Greenstein DLA - engID - CA09592/CA/NCIID - GM57173/GM/NIGMSID - GM58008/GM/NIGMSID - HD07043/HD/NICHDID - HD25614/HD/NICHDPT - Journal ArticleCY - United StatesTA - ScienceJID - 0404511RN - 0 (Carrier Proteins)RN - 0 (Helminth Proteins)RN - 0 (MAP Kinase Signaling System)RN - 0 (Membrane Proteins)RN - 0 (Recombinant Proteins)RN - 0 (VAP-33 protein)RN - 0 (major sperm protein, nematode)RN - EC 2.7.1.- (Mitogen-Activated Protein Kinases)SB - IM
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[
Proc Natl Acad Sci U S A.,
2005]
MicroRNAs (miRNAs) are a recently discovered set of regulatory genes that constitute up to an estimated 1% of the total number of genes in animal genomes, including Caenorhabditis elegans, Drosophila, mouse, and humans [Lagos-Quintana, M., Rauhut, R., Lendeckel, W. M Tuschl, T. (2001) Science 294, 853-858; Lai, E. C., Tomancak, P., Williams, R. W. M Rubin, G.M. (2003) Genome Biol. 4, R42; Lau, N. C., Lim, L. P., Weinstein, E. G. M Bartel, D. P. (2001) Science 294, 858-862; Lee, R. C. M Ambros, V. (2001) Science 294, 862-8644; and Lee, R. C., Feinbaum, R. L. M Ambros, V. (1993) Cell 115, 787-798]. In animals, miRNAs regulate genes by attenuating protein translation through imperfect base pair binding to 3' UTR sequences of target genes. A major challenge in understanding the regulatory role of miRNAs is to accurately predict regulated targets. We have developed an algorithm for predicting targets that does not rely on evolutionary conservation. As one of the features of this algorithm, we incorporate the folded structure of mRNA. By using Drosophila miRNAs as a test case, we have validated our predictions in 10 of 15 genes tested. One of these validated genes is mad as a target for bantam. Furthermore, our computational and experimental data suggest that miRNAs have fewer targets than previously reported.
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[
PLoS One,
2013]
Enteropathogenic Escherichia coli (EPEC), enterohemorrhagic E. coli (EHEC) and enteroaggregative E. coli (EAEC) are intestinal pathogens that cause food and water-borne disease in humans. Using biochemical methods and NMR-based comparative metabolomics in conjunction with the nematode Caenorhabditis elegans, we developed a bioassay to identify secreted small molecules produced by these pathogens. We identified indole, indole-3-carboxaldehyde (ICA), and indole-3-acetic acid (IAA), as factors that only in combination are sufficient to kill C. elegans. Importantly, although lethal to C. elegans, these molecules downregulate several bacterial processes important for pathogenesis in mammals. These include motility, biofilm formation and production of Shiga toxins. Some pathogenic E. coli strains are known to contain a Locus of Enterocyte Effacement (LEE), which encodes virulence factors that cause "attaching and effacing" (A/E) lesions in mammals, including formation of actin pedestals. We found that these indole derivatives also downregulate production of LEE virulence factors and inhibit pedestal formation on mammalian cells. Finally, upon oral administration, ICA inhibited virulence and promoted survival in a lethal mouse infection model. In summary, the C. elegans model in conjunction with metabolomics has facilitated identification of a family of indole derivatives that broadly regulate physiology in E. coli, and virulence in pathogenic strains. These molecules may enable development of new therapeutics that interfere with bacterial small-molecule signaling.