Watts JL et al. (1994) Worm Breeder's Gazette "zu170 Defines a New Gene, par-6, and Can Act as a Suppressor of par-2"

Watts JL, Kemphues KJ

[Worm Breeder's Gazette, 1994]

zul70 defines a new gene, par-6, and can act as a suppressor of par-2 Jennifer Watts and Ken Kemphues Genetics and Development, Cornell University, Ithaca NY 14853

Mattout, Anna et al. (2017) International Worm Meeting "Mechanism and function of genome organization in muscle development and integrity."

Kalck, Veronique, Harr, Jennifer C., Gonzalez-Sandoval, Adriana, Mattout, Anna, Gasser , Susan M.

[International Worm Meeting, 2017]

The loss of nuclear structural integrity leads to tissue-specific pathologies in a set of human diseases called laminopathies. These diseases, such as Emery Dreifuss Muscular Dystrophy (EDMD), are late-onset, tissue-specific, and degenerative. A C. elegans mutant that recreates the EDMD phenotypes arises from the introduction of a specific gain-of-function mutation into lamin (Y59C), which affects the proper release of a muscle-specific heterochromatic reporter from the nuclear periphery. We found that this muscle-specific misorganization of heterochromatin correlates with transcriptional defects and with perturbed locomotion and muscle integrity in C. elegans. To identify if chromatin misorganization is a cause or an effect of these physiological defects or if the alteration of gene expression is the primary cause, we took advantage of a cec-4 deletion mutant. The perinuclear C. elegans chromodomain protein-4 (CEC-4) anchors heterochromatin by binding H3K9 methylation. The mutant releases H3K9me containing heterochromatin from the nuclear periphery in embryos and does not alter transcription. In a strain that contains the cec-4 deletion, expresses the lamin Y59C mutant and harbors a muscle-specific heterochromatic reporter, there is a recovery of the proper positioning of the muscle-specific heterochromatic array in muscle. Additionally, we found that the cec-4 mutation rescues the impaired locomotion phenotype of the lamin mutant. This argues that the lamin-induced sequestration or retention of tissue specific genes in a heterochromatic compartment drives defects that can be overcome by reversing perinuclear sequestration. To identify the mechanism behind this phenomenon we are using in vivo biochemical tagging in the LMN-1 Y59C mutant and wild-type counterpart to identify perinuclear components that mediate sequestration of muscle-specific gene promoters. By identifying the proteins involved in this process, we can determine the mechanism in which misorganization of chromatin can lead to a loss of tissue integrity.

Jennifer Pilipiuk et al. (2006) European Worm Meeting "Analysis of Epithelial Genes during Postembryonic Development of C. elegans"

Olaf Bossinger, Jennifer Pilipiuk, Gisela Helbig

[European Worm Meeting, 2006]

Jennifer Pilipiuk, Gisela Helbig and Olaf Bossinger. We wish to understand how epithelial polarity and tissue integrity is maintained. Here, we consider the role of DLG-1 (Discs large), LET-413 (Scribble), ERM-1 (Ezrin-Radixin-Moesin), and the catenin-cadherin complex (HMP-1HMP-2HMR-1) during postembryonic development of C. elegans. In the course of embryogenesis these genes play an important role in the establishment and maintenance of epithelial polarity, the formation of the lumen, and cell-cell adhesion. In contrast, during larval and adult development only newly established epithelia (e.g. the spermatheka or the vulva) show severe defects after bacterial RNAi against DLG-1, LET-413 and ERM-1, while the depletion of the catenin-cadherin complex seems not to cause visible defects. Nevertheless, how polarity of already established epithelia (e.g. the intestine or the hypodermis) is maintained during postembryonic development remains elusive. In the case of DLG-1, our results suggest that a small amount of protein is sufficient, but cannot fall below a certain threshold without causing defects. Intestinal and hypodermal polarity during larval and adult development of C. elegans might also depend on other, so far unidentified proteins. A detailed analysis of DLG-1, LET-413 and ERM-1 phenotypes during postembryonic epithelial development in C. elegans will be presented and discussed.

Zhao Y et al. (2007) BMC Genomics "Poly-G/poly-C tracts in the genomes of Caenorhabditis."

Zhao Y, O'Neil NJ, Rose AM

[BMC Genomics, 2007]

ABSTRACT: BACKGROUND: In the genome of Caenorhabditis elegans, homopolymeric poly-G/poly-C tracts (G/C tracts) exist at high frequency and are maintained by the activity of the DOG-1 protein. The frequency and distribution of G/C tracts in the genomes of C. elegans and the related nematode, C. briggsae were analyzed to investigate possible biological roles for G/C tracts. RESULTS: In C. elegans, G/C tracts are distributed along every chromosome in a non-random pattern. Most G/C tracts are within introns or are close to genes. Analysis of SAGE data showed that G/C tracts correlate with the levels of regional gene expression in C. elegans. G/C tracts are over-represented and dispersed across all chromosomes in another Caenorhabditis species, C. briggase. However, the positions and distribution of G/C tracts in C. briggsae differ from those in C. elegans. Furthermore, the C. briggsae dog-1 ortholog CBG19723 can rescue the mutator phenotype of C. elegans dog-1 mutants. CONCLUSIONS: The abundance and genomic distribution of G/C tracts in C. elegans, the effect of G/C tracts on regional transcription levels, and the lack of positional conservation of G/C tracts in C. briggsae suggest a role for G/C tracts in chromatin structure but not in the transcriptional regulation of specific genes.

Bhagwati P Gupta et al. (2002) West Coast Worm Meeting "Genetic analysis of the vulval mutants in C. briggsae"

Shahla Gharib, Bhagwati P Gupta, Paul W Sternberg, Jennifer X Li

[West Coast Worm Meeting, 2002]

To understand the evolution of developmental mechanisms, we are doing a comparative analysis of vulval patterning in C. elegans and C. briggsae. C. briggsae is closely related to C. elegans and has identical looking vulval morphology. However, recent studies have indicated subtle differences in the underlying mechanisms of development. The recent completion of C. briggsae genome sequence by the C. elegans Sequencing Consortium is extremely valuable in identifying the conserved genes between C. elegans and C. briggsae.

Antika TR et al. (2023) J Biol Chem "Sequence-specific targeting of C. elegans C-Ala to the D-loop of tRNAAla."

Horng JC, Hsu HL, Nazilah KR, Wang CC, Wang TL, Wang SC, Antika TR, Chuang TH, Chrestella DJ, Wang SW, Tseng YK, Pan HC

[J Biol Chem, 2023]

Alanyl-tRNA synthetase (AlaRS) retains a conserved prototype structure throughout its biology. Nevertheless, its C-terminal domain (C-Ala) is highly diverged and has been shown to play a role in either tRNA or DNA binding. Interestingly, we discovered that Caenorhabditis elegans cytoplasmic C-Ala (Ce-C-Ala_c) robustly binds both ligands. How Ce-C-Ala_c targets its cognate tRNA and whether a similar feature is conserved in its mitochondrial counterpart remain elusive. We show that the N- and C-terminal subdomains of Ce-C-Ala_c are responsible for DNA and tRNA binding, respectively. Ce-C-Ala_c specifically recognized the conserved invariant base G¹⁸ in the D-loop of tRNA^Ala through a highly conserved lysine residue, K934. Despite bearing little resemblance to other C-Ala domains, C. elegans mitochondrial C-Ala (Ce-C-Ala_m) robustly bound both tRNA^Ala and DNA and maintained targeting specificity for the D-loop of its cognate tRNA. This study uncovers the underlying mechanism of how C. elegans C-Ala specifically targets the D-loop of tRNA^Ala.

Blumenthal TE et al. (1994) Worm Breeder's Gazette "C. elegans U2AF 65."

Zorio DAR, Lea K, Blumenthal TE

[Worm Breeder's Gazette, 1994]

C. elegans U2AF65

Oomura, S. et al. (2019) International Worm Meeting "Early embryogenesis of C. inopinata, a sibling species of C.elegans."

Matsumura, Y., Haruta, N., Hoshi, Y., Sugimoto, A., Oomura, S.

[International Worm Meeting, 2019]

C. inopinata is a newly discovered sibling species of C. elegans. Despite their phylogenetic closeness, they have many differences in morphology and ecology. For example, while C. elegans is hermaphroditic, C. inopinata is gonochoristic; C. inopinata is nearly twice as long as C. elegans. A comparative analysis of C. elegans and C. inopinata enables us to study how genomic changes cause these phenotypic differences. In this study, we focused on early embryogenesis of C. inopinata. First, by the microparticle bombardment method we made a C. inopinata line that express GFP::histone in whole body, and compared the early embryogenesis with C. elegans by DIC and fluorescent live imaging. We found that the position of pronuclei and polar bodies were different between these two species. In C. elegans, the female and male pronuclei first become visible in anterior and posterior sides, respectively, then they meet at the center of embryo. On the other hand, the initial position of pronuclei were more closely located in C. inopinata. Also, the polar bodies usually appear in the anterior side of embryo in C. elegans, but they appeared at random positions in C. inopinata. Therefore, we infer that C. inopinata may have a different polarity formation mechanism from that in C. elegans. We are also analyzing temperature dependency of embryogenesis in C. inopinata, whose optimal temperature is ~7 degree higher than that in C. elegans.

Guven K (1995) Journal of Thermal Biology "Differential expression of hsp70 proteins in response to heat and cadmium in Caenorhabditis elegans."

Guven K

[Journal of Thermal Biology, 1995]

1. The patterns of HSP70 expression induced in Caenorhabditis elegans by mild (31 degrees C) or severe (34 degrees C) heat shock, and by cadmium ions at 31 degrees C, have been compared with those expressed constitutively ill 20 degrees C controls by 1- and a-dimensional immunoblotting. 2. The 2D spot patterns become more complex with increasing severity of stress (34 degrees C > 31 degrees C + Cd > 31 degrees C > 20 degrees C). 3. A stress-inducible transgene construct is minimally active at 31 degrees C, but is abundantly expressed in the presence of cadmium or at 34 degrees C. 4. Differing degrees or types of stress may differentially induce available hsp70

Xu J et al. (2018) J Nanosci Nanotechnol "Carbon Quantum Dots as Fluorescent Probes for Imaging and Detecting Free Radicals in C. elegans."

Wang Q, Guan S, Wang L, Wang M, Zhang Y, Mu Y, Xu J, Wang K, Li J

[J Nanosci Nanotechnol, 2018]

Uniform and hydrophilic carbon quantum dots (C-QDs) were synthesized by calcination and NaOH treatment from an organo-templated zeolite precursor. The color of luminescence was determined by the concentration of C-QDs. These variable-color C-QDs were applied for the first time in the imaging of Caenorhabditis elegans (C. elegans) as a model organism. The effects of C-QDs and possible behavioral changes in C. elegans were evaluated under treatment conditions. We could clearly observe distribution of C-QDs in C. elegans from the fluorescence images. Furthermore, we observed significant and detectable fluorescence quenching of the C-QDs by free radicals in C. elegans. Our work affirms that C-QDs can be developed as imaging probes and as potential fluorescent quantitative probes for detecting free radicals.