Okimoto R et al. (1992) Genetics "The mitochondrial genomes of two nematodes, Caenorhabditis elegans and Ascaris suum."

Okimoto R, Wolstenholme DR, Macfarlane JL, Clary DO

[Genetics, 1992]

The nucleotide sequences of the mitochondrial DNA (mtDNA) molecules of two nematodes, Caenorhabditis elegans [13,794 nucleotide pairs (ntp)], and Ascaris suum (14,284 ntp) are presented and compared. Each molecule contains the genes for two ribosomal RNAs (s-rRNA and l-rRNA), 22 transfer RNAs (tRNAs) and 12 proteins, all of which are transcribed in the same direction. The protein genes are the same as 12 of the 13 protein genes found in other metazoan mtDNAs: Cyt b, cytochrome b; COI-III, cytochrome c oxidase subunits I-III; ATPase6, Fo ATPase subunit 6; ND1-6 and 4L, NADH dehydrogenase subunits 1-6 and 4L: a gene for ATPase subunit 8, common to other metazoan mtDNAs, has not been identified in nematode mtDNAs. The C. elegans and A. suum mtDNA molecules both include an apparently noncoding sequence that contains runs of AT dinucleotides, and direct and inverted repeats (the AT region: 466 and 886 ntp, respectively). A second, apparently noncoding sequence in the C. elegans and A. suum mtDNA molecules (109 and 117 ntp, respectively) includes a single, hairpin-forming structure. There are only 38 and 89 other intergenic nucleotides in the C. elegans and A. suum mtDNAs, and no introns. Gene arrangements are identical in the C. elegans and A. suum mtDNA molecules except that the AT regions have different relative locations. However, the arrangement of genes in the two nematode mtDNAs differs extensively from gene arrangements in all other sequenced metazoan mtDNAs. Unusual features regarding nematode mitochondrial tRNA genes and mitochondrial protein gene initiation codons, previously described by us, are reviewed. In the C. elegans and A. suum mt-genetic codes, AGA and AGG specify serine, TGA specifies tryptophan and ATA specifies methionine. From considerations of amino acid and nucleotide sequence similarities it appears likely that the C. elegans and A. suum ancestral lines diverged close to the time of divergence of the cow and human ancestral lines, about 80 million years ago.

Wolstenholme DR et al. (1987) Proc Natl Acad Sci U S A "Bizarre tRNAs inferred from DNA sequences of mitochondrial genomes of nematode worms."

Macfarlane JL, Okimoto R, Clary DO, Wahleithner JA, Wolstenholme DR

[Proc Natl Acad Sci U S A, 1987]

The complete nucleotide sequence of the mitochondrial DNA (mtDNA) molecule of the parasitic nematode worm Ascaris suum has been determined. This molecule lacks genes for tRNAs of the standard form. Instead, 21 sequences are found that can be folded into structures that resemble tRNAs in which the T psi C arm and variable loop are missing and replaced with a single loop of between 4 and 12 nucleotides. Considerations of various properties of these sequences, including the number, predicted anticodons, conserved nucleotides, direction of transcription, base composition, and relative gene arrangements are consistent with the interpretation that they are genes for a different sort of tRNA. Transfer RNA genes with a similar potential secondary structure are found in mtDNA of the free-living nematode Caenorhabditis elegans, suggesting that this unusual form of tRNA is used by all nematode mitochondria.

Peter Swoboda et al. (2002) European Worm Meeting "A multifaceted approach to elucidate the regulation of ciliogenesis in C. elegans"

Evgeni Efimenko, Peter Swoboda

[European Worm Meeting, 2002]

Cilia are evolutionarily conserved subcellular organelles functioning in cell motility, movement of extracellular fluids, sensory perception (e.g. smell) and determination of left-right asymmetry. While a great deal is known about the structure, function and motility of cilia, very little is known about the molecular mechanisms that regulate ciliogenesis in a cell-type specific and developmental manner. How do cilia become functional? How can they do what they do?

Ashrafi K (2022) Cell Host Microbe "Better living through communal eating."

Ashrafi K

[Cell Host Microbe, 2022]

Caenorhabditis elegans do not grow on either Staphylococcus saprophyticus or heat-killed Escherichia coli, but do so when exposed to both. In this issue of Cell Host & Microbe, Geng and colleagues have identified E.coli-derived signals as well as the host's neural and innate immunity pathways that promote digestion of S.saprophyticus.

Doitsidou M et al. (2008) Nat Methods "Automated screening for mutants affecting dopaminergic-neuron specification in C. elegans."

Flames N, Lee AC, Boyanov A, Doitsidou M, Hobert O

[Nat Methods, 2008]

We describe an automated method to isolate mutant Caenorhabditis elegans that do not appropriately execute cellular differentiation programs. We used a fluorescence-activated sorting mechanism implemented in the COPAS Biosort machine to isolate mutants with subtle alterations in the cellular specificity of GFP expression. This methodology is considerably more efficient than comparable manual screens and enabled us to isolate mutants in which dopamine neurons do not differentiate appropriately.

Ambros V (2010) Curr Biol "MicroRNAs: genetically sensitized worms reveal new secrets."

Ambros V

[Curr Biol, 2010]

Why do many microRNA gene mutants display no evident phenotype? Multiply mutant worms that are selectively impaired in genetic regulatory network activities have been used to uncover previously unknown functions for numerous Caenorhabditis elegans microRNAs.

Bowerman B (2006) Curr Biol "Left-right asymmetry: making the right decision early."

Bowerman B

[Curr Biol, 2006]

A left-right asymmetry in neuronal function is specified surprisingly early during embryogenesis in Caenorhabditis elegans. Do early cues influence left-right asymmetries in other animals? How are early cues remembered until late in development?

Chamberlin HM (2000) Curr Biol "Nematode development: An evolutionary fugue."

Chamberlin HM

[Curr Biol, 2000]

Recent studies of vulva development in the nematode Pristionchus pacificus have identified cell interactions that do not appear to occur in Caenorhabditis elegans, The new results underscore the diversity of patterning mechanisms that can produce structures with similar cellular morphology.

Soh CT et al. (1966) Kisaengchunghak Chapchi "Clinical manifestation of Brugia malayi infection in Korea."

Soh CT, Lee KT, Im SW, Lee JH

[Kisaengchunghak Chapchi, 1966]

The clinical manifestations in filarial infection were examined during 1965-1966 from the known endemic areas: Yongju, a mountainous inland area and Cheju-Do, an island. 1. All the microfilaria which were found during the survey were Brugia malayi. 2. The principal symptom was cuticular hypertrophy (elephantiasis). It was found in 4 cases from Yongju among 707 villagers, 84 cases from Cheju-Do among 2,376 villagers. 3. Four microfilaremia cases (4.5%) were found among a total of 88 cases of elephantiasis. 4. In Cheju-Do, the higher incidence of elephantiasis was observed among people over 20 years old and the females showed much higher incidence than males (30 males and 54 females). 5. The cuticular hypertrophic changes (elephantiasis) appeared more often in the lower extremities(77%) than in the upper part of the body, and in the right side than in the left.

Hahn BS et al. (2001) Curr Biol "Tissue integrity: Hemidesmosomes and resistance to stress."

Hahn BS, Labouesse M

[Curr Biol, 2001]

How do animal tissues resist the shearing forces to which they are exposed during locomotion or harsh encounters with the environment? Genetic analysis in Caenorhabditis elegans is furthering our understanding of the nature and function of the attachments that preserve tissue integrity.