Lee, Tongyoung et al. (2019) International Worm Meeting "FMRF-like neuropeptide controls a C. elegans putative maternal behavior in a 3D environment."

Lee, Tongyoung, Lee, Jin I., Yoon, Kyoung-hye

[International Worm Meeting, 2019]

Parental behaviors are an essential evolutionary adaptation for the benefit of offspring survival. Although C. elegans mothers display the ultimate sacrifice in harsh environments by choosing to internally hatch, it is difficult to observe any outward care towards their young on a standard NGM plate. It is unknown, however, if C. elegans displays different behaviors in natural 3D environments such as rotting fruit and soil compost. To investigate the biology of C. elegans in 3D, we designed a cultivation habitat which we term NGT-3D and NGB-3D. Growth, brood size, and lifespan in NGT-3D are comparable with 2D NGM plate. Interestingly, wild-type worms display dwelling and egg-laying behaviors in a stereotypical pattern in NGB-3D that is not observed in regular plates: the mother worms spread the bacteria in a "nest" like pattern, remain near the edge of this nest, and move away from the bacteria to lay their eggs. We found that an FMR-like neuropeptide FLP-17 and its cognate receptor EGL-6 both play a role in this maternal egg-laying behavior. Although loss-of-function mutants of egl-6 and flp-17 show generally normal locomotion behavior, unlike wild-type, they do not move away from the bacteria to lay their eggs. When flp-17 mutants mothers are cultivated in NGT-3D, we find that they have lower reproductive fitness compared to N2. We are investigating the relationship between fitness and FLP-17-mediated maternal behavior. Finally, we will determine whether any environmental factor is related with these listed stereotypical behaviors and FMRF-like neuropeptide signaling. Interestingly, flp-17 is expressed in the BAG neuron involved in O2 and CO2 sensing. However, other candidate O2 sensing mutants still show a similar wild type-like behavior in 3D. In the future, we hope to describe a molecular and genetic picture of a maternal behavior circuitry in C. elegans.

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

Blackwell TK, Abate JP

[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 <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.

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 <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.

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.