Salazar, C. J. et al. (2017) International Worm Meeting "Characterizing the function of a novel allele (dz205) in the development of PVD."

Bulow, H. E., Salazar, C. J., Diaz-Blazac, C. A.

[International Worm Meeting, 2017]

Neuronal development depends on numerous extracellular and intracellular cues to ensure proper dendritic structure and function. However, the mechanisms, which control and ensure proper dendritic development, are incompletely understood and are difficult to study in vivo within vertebrates. C. elegans is an excellent model to determine when and where genetic and molecular signals may be required during different stages of development. In order to better understand dendrite development, we utilized the somatosensory neuron, PVD, with its highly stereotyped 'menorah'-like dendrites. These dendrites are formed through consecutive branching formation of primary, secondary, tertiary, and quaternary dendritic branches. During a genetic screen, we have isolated a mutant allele, dz205, which elicits a characteristic "hyper-branched" phenotype in which the number of dendritic branches of the PVD somatosensory neuron increases. In order to quantify this phenotype, we utilized morphometric analysis to characterize the morphology of PVD at the L4 larval stage. We found the number of ectopic secondary and tertiary increased in mutant animals compared to the wildtype. This finding suggests that the normal function of dz205 is to limit the formation of ectopic branches of PVD dendrites. Currently, our research aims to identify the gene mutant in dz205 and to determine in which tissue the corresponding gene may act during the development of PVD dendrites.

(2019) Development "The people behind the papers - Eduardo Leyva-Diaz and Oliver Hobert."

[Development, 2019]

Transcriptional autoregulation occurs when transcription factors bind their own <i>cis</i>-regulatory sequences, ensuring their own continuous expression along with expression of other targets. During development, continued expression of identity-specifying transcription factors can be achieved by autoregulation, but until now formal evidence for a developmental requirement of autoregulation has been lacking. A new paper in Development provides this proof with the help of CRISPR/Cas9 gene editing in the <i>C. elegans</i> nervous system<i>.</i> We caught up with the paper's two authors: postdoc Eduardo Leyva-Diaz and his supervisor Oliver Hobert, Professor of Biological Sciences and HHMI Investigator at Columbia University, New York, to find out more about the work.

Peleg AY et al. (2008) Proc Natl Acad Sci U S A "Prokaryote-eukaryote interactions identified by using Caenorhabditis elegans."

Mylonakis E, Eliopoulos GM, Peleg AY, Tampakakis E, Fuchs BB, Moellering RC

[Proc Natl Acad Sci U S A, 2008]

Prokaryote-eukaryote interactions are ubiquitous and have important medical and environmental significance. Despite this, a paucity of data exists on the mechanisms and pathogenic consequences of bacterial-fungal encounters within a living host. We used the nematode Caenorhabditis elegans as a substitute host to study the interactions between two ecologically related and clinically troublesome pathogens, the prokaryote, Acinetobacter baumannii, and the eukaryote, Candida albicans. After co-infecting C. elegans with these organisms, we observed that A. baumannii inhibits filamentation, a key virulence determinant of C. albicans. This antagonistic, cross-kingdom interaction led to attenuated virulence of C. albicans, as determined by improved nematode survival when infected with both pathogens. In vitro coinfection assays in planktonic and biofilm environments supported the inhibitory effects of A. baumannii toward C. albicans, further showing a predilection of A. baumannii for C. albicans filaments. Interestingly, we demonstrate a likely evolutionary defense by C. albicans against A. baumannii, whereby C. albicans inhibits A. baumannii growth once a quorum develops. This counteroffensive is at least partly mediated by the C. albicans quorum-sensing molecule farnesol. We used the C. elegans-A. baumannii-C. albicans coinfection model to screen an A. baumannii mutant library, leading to the identification of several mutants attenuated in their inhibitory activity toward C. albicans. These findings present an extension to the current paradigm of studying monomicrobial pathogenesis in C. elegans and by use of genetic manipulation, provides a whole-animal model system to investigate the complex dynamics of a polymicrobial infection.

Kuersten S et al. (1994) Worm Breeder's Gazette "Mono- and Polycistronic pre-mRNA Splicing in a C. elegans Embryo Extract."

Blumenthal TE, Kuersten S

[Worm Breeder's Gazette, 1994]

Mono- and Polycistronic pre-mRNA Splicing in a C. elegans embryo extract

Freyd G et al. (1990) Nature "Novel cysteine-rich motif and homeodomain in the product of the Caenorhabditis elegans cell lineage gene lin-11."

Freyd G, Kim SK, Horvitz HR

[Nature, 1990]

The gene lin-11 is required for the asymmetric division of a vulval precursor cell type in the nematode Caenorhabditis elegans. Putative lin-11 complementary DNAs were sequenced and found to encode a protein that contains both a homeodomain and two tandem copies of a novel cysteine-rich motif: C-X2-C-X17-19-H-X2-C-X2-C-X2-C-X7-11-(C)-X8-C. Two tandem copies of this motif are also present amino-terminal to the homeodomains in the proteins encoded by the genes mec-3, which is required for C. elegans touch neuron differentiation, and isl-1, which encodes a rat insulin I gene enhancer-binding protein. The arrangement of cysteine residues in this motif, referred to as LIM (for lin-11 isl-1 mec-3), suggests that this region is a metal-binding domain. The presence in these three proteins of both a potential metal-binding domain and a homeodomain distinguishes them from previously characterized proteins.

Jin X et al. (2021) BMC Microbiol "Lactic acid bacteria that activate immune gene expression in Caenorhabditis elegans can antagonise Campylobacter jejuni infection in nematodes, chickens and mice."

Chen X, He Y, Lee YK, Chen W, Jin X, Zhang H, Zhou Y, Zhao J, Wang G

[BMC Microbiol, 2021]

BACKGROUND: Campylobacter jejuni is the major micro-bacillary pathogen responsible for human coloenteritis. Lactic acid bacteria (LAB) have been shown to protect against Campylobacter infection. However, LAB with a good ability to inhibit the growth of C. jejuni in vitro are less effective in animals and animal models, and have the disadvantages of high cost, a long cycle, cumbersome operation and insignificant immune response indicators. Caenorhabditis elegans is increasingly used to screen probiotics for their anti-pathogenic properties. However, no research on the use of C. elegans to screen for probiotic candidates antagonistic to C. jejuni has been conducted to date. RESULTS: This study established a lifespan model of C. elegans, enabling the preselection of LAB to counter C. jejuni infection. A potential protective mechanism of LAB was identified. Some distinct LAB species offered a high level of protection to C. elegans against C. jejuni. The LAB strains with a high protection rate reduced the load of C. jejuni in C. elegans. The transcription of antibacterial peptide genes, MAPK and Daf-16 signalling pathway-related genes was elevated using the LAB isolates with a high protection rate. The reliability of the lifespan model of C. elegans was verified using mice and chickens infected with C. jejuni. CONCLUSIONS: The results showed that different LAB had different abilities to protect C. elegans against C. jejuni. C. elegans provides a reliable model for researchers to screen for LAB that are antagonistic to C. jejuni on a large scale.

L'Hernault SW et al. (2000) The Testis: From Stell Cell to Sperm Function. E Goldberg (ed). Springer-Verlag, New York. "Developmental genetics of spermatogenesis in the nematode Caenorhabditis elegans."

Singson AW, L'Hernault SW

["The Testis: From Stell Cell to Sperm Function". E Goldberg (ed). Springer-Verlag, New York., 2000]

In both mammals and C. elegans, spermatogenesis is the process where a spermatogonial cell undergoes a series of divisions to produce a highly differentiated cell, the spermatozoon. Spermatogonial cellular divisions are incomplete in mammals so that all subsequent stages occur in a syncitium. The situation is similar in C. elegans, where spermatogonial nuclei initially share a common cytoplasm. Spermatogonial divisions in both mammals and C. elegans are regulated by signaling from gonadal accessory

Ding Q et al. (2022) G3 (Bethesda) "Highly efficient transgenesis with miniMos in Caenorhabditis briggsae."

Ding Q, Ren X, Xie D, Chan L, Li R, Ho VWS, Zhao Z, Bi Y

[G3 (Bethesda), 2022]

C. briggsae as a companion species for C. elegans has played an increasingly important role in study of evolution of development, gene regulation and genome. Aided by the isolation of its sister spices, it has recently been established as a model for speciation study. To take full advantage of the species for comparative study, an effective transgenesis method especially those with single-copy insertion is important for functional comparison. Here we improved a transposon-based transgenesis methodology that had been originally developed in C. elegans but worked marginally in C. briggsae. By incorporation of a heat shock step, the transgenesis efficiency in C. briggsae with a single-copy insertion is comparable to that in C. elegans. We used the method to generate 54 independent insertions mostly consisting of a mCherry tag over the C. briggsae genome. We demonstrated the use of the tags in identifying interacting loci responsible for hybrid male sterility between C. briggsae and C. nigoni when combined with the GFP tags we generated previously. Finally, we demonstrated that C. briggsae tolerates the C. elegans toxin, PEEL-1, but not SUP-35, making the latter a potential negative selection marker against extrachromosomal array.

Infarinato N (2019) J Cell Biol "Xiaochen Wang: Building up our understanding of breaking down."

Infarinato N

[J Cell Biol, 2019]

Wang studies lysosomal degradation pathways using <i>C. elegans</i> as a model system.

Jeong DE et al. (2018) Methods Mol Biol "Western Blot Analysis of C. elegans Proteins."

Lee SV, Jeong DE, Lee Y

[Methods Mol Biol, 2018]

C. elegans has been widely used as a model organism for basic biological research and is particularly amenable for molecular genetic studies using a broad repertoire of techniques. Biochemical approaches, including Western blot analysis, have emerged as a powerful tool in C. elegans biology for understanding molecular mechanisms that link genotypes to phenotypes. Here, we provide a protocol for Western blot analysis using protein extracts obtained from C. elegans samples.