Matheson C et al. (1991) Worm Breeder's Gazette "TOWARDS THE CLONING UNC-"

Baillie DL, McKim KS, Matheson C

[Worm Breeder's Gazette, 1991]

We are trying to clone and sequence the muscle gene unc-60, located on the left end of LGV. The genetic organization of the unc-60 region has been described previously by Kim McKim (McKim et al., 1988). Subsequently, cosmid microinjections were performed and a rescue was achieved, localizing this gene to a deleted 22 kb cosmid, F53E2 (M. Wakarchuk, WBG Vol. 11, #1). To identify the unc-60 sequences we have tried two approaches. First, genomic DNA prepared from N2 and three gamma induced alleles was digested with HindIII, SalI and EcoRI and blotted. These Southerns when probed with the entire cosmid were uninformative. The second approach was to identify sequences conserved in C. briggsae. We have constructed a restriction map of the cosmid. Southern blot analysis using various cosmid subclones has shown that there are several classes of repetitive DNA within this cosmid. Subclones containing these repetitive sequences hybridize to many C. briggsae fragments at low stringency. A 5 kb PstI fragment was found that contains no repetitive elements but exhibits C. briggsae homology. This fragment was used to screen 30,000 phage plaques from a lambda ZAP cDNA library (a gift from R. Barstead and R. Waterston) resulting in the isolation of 12 cDNA's which range in size from 500 bp to 1500 bp. The 5 kb PstI fragment and an overlapping non-repetitive 6 kb HindIII fragment are now being used for microinjection in attempts to rescue unc-60 (M. Wakarchuk per. com.). As we are unsure of the number of coding elements within the cosmid additional cDNA screens are currently underway. Sequencing of the repetitive DNA and the cDNA's will follow.

Matheson C et al. (1992) Worm Breeder's Gazette "The Molecular Analysis of unc-60"

Wakarchuk MF, McKim KS, Baillie DL, Matheson C

[Worm Breeder's Gazette, 1992]

We have been cloning and sequencing the muscle gene unc-60 ,located on the left end of LGV. The genetic organization of the unc-60 region has been described previously by K. McKim (McKim et al. ,1988). Transformation rescue localized unc-60 to a deleted 22 kb cosmid, F53E2 (M. Wakarchuk, WBG Vol. 11, #1). A restriction map of the cosmid has been constructed. Various subcloned fragments spanning the entire cosmid were used to screen a lambda Zap cDNA library (a gift from R. Barstead and R. Waterston) resulting in the isolation of cDNA clones representing two coding regions. Sequencing of cDNA and genomic clones of one of the coding regions has revealed that at least two cofilin/destrin like proteins are produced through alternate splicing. Each transcript has 5 exons, sharing only the first which is untranslated except for a single methionine residue. Cofilin and destrin are actin binding proteins which facilitate actin polymerization and/or depolymerization. This function is consistent with the unc-60 mutant phenotype ie. disorganized thin filaments (Waterston et al., 1980). The only lethal allele of unc-60 ,s1586 ,was studied using PCR and Southern blot analysis and was shown to contain an approximately 500 bp deletion which affects both transcripts. Currently, a 10 kb BamH1 fragment, which contains the coding regions for both cofilin/destrin like proteins, is being isolated for microinjections in an attempt to rescue unc-60 .As well, PCR products from homozygous unc-60 EMS induced mutants are being sequenced to identify their molecular nature.

McKim KS et al. (1994) Mol Gen Genet "The Caenorhabditis elegans unc-60 gene encodes proteins homologous to a family of actin-binding proteins."

Matheson C, Baillie DL, Wakarchuk MF, McKim KS, Marra MA

[Mol Gen Genet, 1994]

Mutations in the unc-60 gene of the nematode Caenorhabditis elegans result in paralysis. The thin filaments of the muscle cells are severely disorganized and not bundled with myosin into functional contractile units. Here we report the cloning and sequence of unc-60. Two unc-60 transcripts, 1.3 and 0.7 kb in size, were detected. The transcripts share a single exon encoding only the initial methionine, yet encode proteins with homologous sequences. The predicted protein products are 165 and 152 amino acids in length and their sequences are 38% identical. Both proteins are homologous to a family of actin depolymerizing proteins identified in vertebrate, plant and protozoan systems. We propose that the unc-60 locus encodes proteins that depolymerize growing actin filaments in muscle cells, and that these proteins are required for the assembly of actin filaments into the contractile myofilament lattice of C. elegans muscle. unc-60 has an essential function in development, since one unc-60 allele, s1586, has a recessive lethal phenotype. Our characterization of s1586 has shown that it is a small deletion which disrupts both coding regions.

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.