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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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[
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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[
Zootaxa,
2022]
Rhagovelia medinae sp. nov., of the hambletoni group (angustipes complex), and R. utria sp. nov., of the hirtipes group (robusta complex), are described, illustrated, and compared with similar congeners. Based on the examination of type specimens, six new synonymies are proposed: R. elegans Uhler, 1894 = R. pediformis Padilla-Gil, 2010, syn. nov.; R. cauca Polhemus, 1997 = R. azulita Padilla-Gil, 2009, syn. nov., R. huila Padilla-Gil, 2009, syn. nov., R. oporapa Padilla-Gil, 2009, syn. nov, R. quilichaensis Padilla-Gil, 2011, syn. nov.; and R. gaigei, Drake Hussey, 1947 = R. victoria Padilla-Gil, 2012 syn. nov. The first record from Colombia is presented for R. trailii (White, 1879), and the distributions of the following species are extended in the country: R. cali Polhemus, 1997, R. castanea Gould, 1931, R. cauca Polhemus, 1997, R. gaigei Drake Hussey, 1957, R. elegans Uhler, 1894, R. femoralis Champion, 1898, R. malkini Polhemus, 1997, R. perija Polhemus, 1997, R. sinuata Gould, 1931, R. venezuelana Polhemus, 1997, R. williamsi Gould, 1931, and R. zeteki Drake, 1953.
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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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[
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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[
PLoS Genet,
2019]
Diet is a crucial determinant of organismal biology; interactions between the host, its diet, and its microbiota are critical to determining the health of an organism. A variety of genetic and biochemical means were used to assay stress sensitivity in C. elegans reared on two standard laboratory diets: E. coli OP50, the most commonly used food for C. elegans, or E. coli HT115, which is typically used for RNAi-mediated gene knockdown. We demonstrated that the relatively subtle shift to a diet of E. coli HT115 had a dramatic impact on C. elegans's survival after exposure to pathogenic or abiotic stresses. Interestingly, this was independent of canonical host defense pathways. Instead the change arises from improvements in mitochondrial health, likely due to alleviation of a vitamin B12 deficiency exhibited by worms reared on an E. coli OP50 diet. Increasing B12 availability, by feeding on E. coli HT115, supplementing E. coli OP50 with exogenous vitamin B12, or overexpression of the B12 transporter, improved mitochondrial homeostasis and increased resistance. Loss of the methylmalonyl-CoA mutase gene
mmcm-1/MUT, which requires vitamin B12 as a cofactor, abolished these improvements, establishing a genetic basis for the E. coli OP50-incurred sensitivity. Our study forges a mechanistic link between a dietary deficiency (nutrition/microbiota) and a physiological consequence (host sensitivity), using the host-microbiota-diet framework.
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[
J Biol Chem,
1990]
The nematode Caenorhabditis elegans (C. elegans) expresses the regulatory subunit (R) of cAMP-dependent protein kinase at a level similar to the levels determined for R subunits in mammalian tissues. Approximately 60% of the C. elegans cAMP-binding protein is tightly associated with particulate structures by noncovalent interactions. Ionic detergents or 7 M urea solubilize particulate R. Solubilized and cytosolic R subunits have apparent Mr values of 52,000 and pI values of 5.5. cDNA and genomic DNA encoding a unique C. elegans R subunit were cloned and sequenced. The derived amino acid sequence contains 375 residues; carboxyl-terminal residues 145-375 are 69% identical with mammalian RI. However, residues 44-145 are markedly divergent from the corresponding regions of all other R sequences. This region might provide sufficient structural diversity to adapt a single R subunit for multiple functional roles in C. elegans. Antibodies directed against two epitopes in the deduced amino acid sequence of C. elegans R avidly bound nematode cytosolic and particulate R subunits on Western blots and precipitated dissociated R subunits and R2C2 complexes from solution. Immunofluorescence analysis revealed that the tip of the head, which contains chemosensory and mechanosensory neurons, and the pharyngeal nerve ring were enriched in R. The R subunit concentration is low during early embryogenesis in C. elegans. A sharp increase (approximately 6-fold) in R content begins several hours before the nematodes hatch and peaks during the first larval stage. Developmental regulation of R expression occurs at translational and/or post-translational levels. The 8-kilobase pair C. elegans R gene is divided into 8 exons by introns ranging from 46 to 4300 base pairs. The 5'-flanking region has no TATA box and contains preferred and minor transcription start sites.
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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.