203 Papers found (0.01 seconds)

Abate JP et al. (2009) Cell Metab "Life is short, if sweet."

[

Cell Metab,

2009]

Insulin is essential for glucose homeostasis, but reducing its activity delays the aging process in model organisms. In this issue of Cell Metabolism, Lee et al. (2009) show how these effects of insulin signaling intersect when glucose is fed to C. elegans.

Lee C et al. (2017) Bio Protoc "Single-molecule RNA Fluorescence in situ Hybridization (smFISH) in Caenorhabditis elegans."

Sorensen EB, Lee C, Seidel HS, Lynch TR, Crittenden SL, Kimble J

[

Bio Protoc,

2017]

Single-molecule RNA fluorescence in situ hybridization (smFISH) is a technique to visualize individual RNA molecules using multiple fluorescently-labeled oligonucleotide probes specific to the target RNA ( Raj et al., 2008 ; Lee et al., 2016a ). We adapted this technique to visualize RNAs in the C. elegans whole adult worm or its germline, which enabled simultaneous recording of nascent transcripts at active transcription sites and mature mRNAs in the cytoplasm ( Lee et al., 2013 and 2016b). Here we describe each step of the smFISH procedure, reagents, and microscope settings optimized for C. elegans extruded gonads.

Ang, Y.J. et al. (2011) International Worm Meeting "Interaction of TGFb regulators, LON-1 and LON-2 with its downstream target, DBL-1."

Lee, J.C.C., Chow, K.L., Wong, C.K.H., Ang, Y.J., Mok, M.

[

International Worm Meeting,

2011]

In C. elegans, TGFb pathway impacts on the body size of the organism in addition to a myriad of other developmental features. The body size of a worm is primarily controlled by endoreduplication that affects the cell size instead of the cell number. Mutants of Lon genes, e.g., lon-1, lon-2 and lon-3, produce worms 1.5 times longer than wild type. These Lon gene products act in the extracellular matrix regulating the body size, and they encode a PR-related protein, a glypican and a collagen, respectively. Their regulatory mechanism, however, remains unclear. Here, we are particularly interested in lon-1 and lon-2 genes which act as negative regulators of the BMP-ligand, DBL-1 in the TGFb pathway. In C, elegans, the effect of LON-1 exerts on DBL-1 was likely through the BMP ligand facilitator, CRM-1, possibly through physical interaction. We mapped the interaction domain between LON-1 and CRM-1 and demonstrated that the LON-1 SCP domain interacts with CR domains on CRM-1. In addition, lon-2 null mutant allele attributed to two large deletions was characterized. While glypican has the ability to bind BMP ligand, we would investigate this interaction between LON-2 glypican and DBL-1 ligand in vivo. Tagged version of both LON-2 and DBL-1 are expressed in transgenic animals for co-immunoprecipitation and domain mapping. The data from these experiments and the implication will be discussed in this poster. (This study is funded by the Research Grants Council, Hong Kong.).

Dawes-Hoang RE et al. (2003) Dev Cell "Bringing classical embryology to C elegans gastrulation."

Zallen JA, Wieschaus EF, Dawes-Hoang RE

[

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.

Bauer, Jack et al. (2021) MicroPubl Biol

Labb, Jean-Claude, Lacroix, La, Bauer, Jack

[

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).

Mondol V et al. (2012) Curr Top Dev Biol "Let's make it happen: the role of let-7 microRNA in development."

Mondol V, Pasquinelli AE

[

Curr Top Dev Biol,

2012]

Noncoding RNAs have emerged as an integral part of posttranscriptional gene regulation. Among that class of RNAs are the microRNAs (miRNAs), which posttranscriptionally regulate target mRNAs containing complementary sequences. The broad presence of miRNAs in lower eukaryotes, plants, and mammals highlights their importance throughout evolution. MiRNAs have been shown to regulate many pathways, including development, and disruption of miRNA function can lead to disease (Ivey and Srivastava, 2010; Jiang et al., 2009). Although the first miRNA genes were discovered in the nematode, Caenorhabditis elegans, almost 20 years ago, the field of miRNA research began when they were found in multiple organisms a little over a decade ago (Lagos-Quintana et al., 2001; Lau et al., 2001; Lee and Ambros, 2001; Lee et al., 1993; Pasquinelli et al., 2000; Wightman et al., 1993). Here, we review one of the first characterized miRNAs, let-7, and describe its role in development and the intricacies of its biogenesis and function.

Ho F et al. (1992) Worm Breeder's Gazette "The Second Approach to Aligning the Genetic and Physical Maps on Chromosome I: PCR mapping of Potential Deletions"

Ho F, Janmaat A, Ha TT, Melathopoulos A, Liu T, Rose AM, Salmon R

[

Worm Breeder's Gazette,

1992]

For the right portion of the chromosome, where we don't have a high density of mapped mutants, we are using the PCR mapping protocol of Barstead and Waterston (in 1991 C Mot Cyto 20:69) to position gamma-induced lethals (potential deletions). Using hIn1 as a balancer (Zetka and Rose, 1992 Genetics), we recovered several lethals linked to unc-101 and lev-11 which were induced with 1500 rads of gamma radiation. Primers were kindly provided by Junho Lee in Paul Sternberg's lab and Yuko Kozono in Bob Waterstons's lab. As controls for the PCR reactions, we are using a deletion outside the hIn1 region, hDf8 ,and primers from bli-4 (Ken Peters, unpublished) and AHH sequences (Prasad, Starr and Rose, in press). hDf8 deletes AHH, but not bli-4 .We have tested nine of our gamma induced lethals to date and one of these hDf14 (h1277 )is lacking DNA for the primer set INT 7-10 from unc-101 sequences provided by Junho Lee.

Miranda MC et al. (2024) MicroPubl Biol "Investigating the effects of antipsychotic drugs as a treatment for improving the activity of the unc-33 /Dpysl2 gene in C. elegans."

Miranda MC, Hyde J, Holgado A, Salazar K, Bell B

[

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 C. elegans , is important for axonal outgrowth and synapse formation. Herein, we study the effects of antipsychotic drugs on developing C.elegans exposed to stress through high temperatures. Results indicate that the unc-33 promoter was not impacted by antipsychotic drug treatment, but the lifespan was decreased.

Neuhaus K et al. (2016) Arch Microbiol "Probiotic Enterococcus faecalis Symbioflor() down regulates virulence genes of EHEC in vitro and decrease pathogenicity in a Caenorhabditis elegans model."

Spanier B, Zolch B, Vogel RF, Ehrmann MA, Simon S, Lamparter MC, Neuhaus K, Landstorfer R

[

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.

Wang ST et al. (2021) Mol Microbiol "OmpR coordinates the expression of virulence factors of enterohemorrhagic Escherichia coli in the alimentary tract of Caenorhabditis elegans."

Wang ST, Kuo CJ, Chen JW, Chen CS, Lee TM, Huang CW

[

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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