Rohrer SP et al. (1994) J Parasitol "Ivermectin binding sites in sensitive and resistant Haemonchus contortus."

Eary CH, Shoop WL, Rohrer SP, Schaeffer JM, Birzin ET

[J Parasitol, 1994]

Membranes from both ivermectin-sensitive and -resistant Haemonchus contortus L3 larvae were examined for the presence of high affinity [3H]ivermectin binding sites. Both tissue preparations displayed high affinity drug binding sites (Kd = 0.13 nM). Receptor density (Bmax = 0.4 pmol/mg) was the same in both the sensitive and resistant nematodes suggesting that target site modification was not involved in the development of drug resistance in this particular strain of H. contortus. The H. contortus ivermectin binding site appeared to be similar to the well characterized Caenorhabditis elegans ivermectin binding site with respect to affinity for ivermectin and receptor density.

Rohrer SP et al. (1990) Comp Biochem Physiol C "A membrane associated glutamate binding protein from Caenorhabditis elegans and Haemonchus contortus."

Bergstrom AR, Evans DV, Rohrer SP

[Comp Biochem Physiol C, 1990]

1. A glutamate binding protein has been identified in membrane preparations from the free living nematode, Caenorhabditis elegans, and from the parasitic nematode, Haemonchus contortus. 2. This putative glutamate receptor was solubilized with 30 mM octyl-B-glucoside and partially purified by anion exchange and gel filtration chromatography. 3. An 80-fold purification with recovery of 75% of the glutamate binding activity was achieved. 4. The soluble C. elegans binding protein displayed a Kd for glutamate of 0.1 microM, in close agreement with the findings for the membrane associated binding protein. 5. Quisqualate was capable of displacing glutamate from the soluble C. elegans receptor, again in agreement with previous findings for the membrane bound receptor. 6. The fact that a parasitic nematode, Haemonchus contortus, also possesses this putative glutamate receptor, strengthens the case for using C. elegans as a model system for the study of parasitic nematode neuromuscular physiology.

Rohrer SP et al. (1992) Proc Natl Acad Sci U S A "Photoaffinity labeling of avermectin binding sites from Caenorhabditis elegans and Drosophila melanogaster."

Mrozik H, Meinke PT, Schaeffer JM, Hayes EC, Rohrer SP

[Proc Natl Acad Sci U S A, 1992]

An azido-avermectin analog [4'' alpha-(4-azidosalicylamido-epsilon-caproylamido-beta-alan ylamido)-4''-deoxyavermectin B1a; azido-AVM] was synthesized and used to photoaffinity label avermectin binding sites present in the membranes of Caenorhabditis elegans and Drosophila melanogaster. Azido-AVM was biologically active and behaved like a competitive inhibitor of [3H]ivermectin binding to C. elegans membranes (Ki = 0.2 nM). Radiolabeled azido-AVM bound specifically and with high affinity to C. elegans membranes (Kd = 0.14 nM) and, upon photoactivation, became covalently linked to three C. elegans polypeptides of 53, 47, and 8 kDa. Photoaffinity labeling of a membrane preparation from D. melanogaster heads resulted in labeling of a single major polypeptide of approximately 47 kDa. The proteins that were covalently tagged in these experiments are believed to be associated with avermectin-sensitive chloride channels present in the neuromuscular systems of C. elegans and D. melanogaster. Azido-AVM did not bind to rat brain membranes and therefore was selective for the nematode and insect receptors.

Rohrer SP et al. (1994) Biochem J "Immunoaffinity purification of avermectin-binding proteins from the free-living nematode Caenorhabditis elegans and the fruitfly Drosophila melanogaster."

Rohrer SP, Jacobson EB, Hayes EC, Birzin ET, Schaeffer JM

[Biochem J, 1994]

Avermectin-binding proteins from the free-living nematode worm Caenorhabditis elegans and from the fruitfly Drosophila melanogaster were purified to homogeneity via a three-step procedure. The binding proteins were covalently labelled using- a radioactive photoaffinity probe and then partially purified on a Sephacryl S-300 gel-filtration column. The radiolabelled binding proteins were then purified by immunoaffinity chromatography using a monoclonal antibody to avermectin covalently attached to Protein A-Sepharose beads. Three affinity-labelled Drosophila proteins with molecular masses between 45 and 50 kDa were isolated in this way and then separated from each other by electroelution. This three-step protocol provides a rapid technique for receptor purification which may be of use in the purification of other binding proteins.

Ross JL et al. (2012) J Helminthol "Diversity and distribution of nematodes associated with terrestrial slugs in the Western Cape Province of South Africa."

Ivanova ES, Wilson MJ, Ross JL, Sirgel WF, Malan AP

[J Helminthol, 2012]

A survey of nematodes associated with native and introduced species of terrestrial slugs was conducted in the Western Cape Province of South Africa, in order to gather new data regarding diversity and distribution. A total of 521 terrestrial slugs were collected from 35 localities throughout the Western Cape. All slugs were dissected and examined for the presence of internal nematodes. Extracted nematodes were identified using a combination of molecular (18S rRNA gene sequencing) and morphological techniques. Nematodes were found parasitizing slugs at 14 of the 35 sites examined, amounting to 40% of sample sites. Of all slugs, 6% were infected with nematodes. A total of seven species of nematode were identified in the province, including Agfa flexilis, Angiostoma sp., Phasmarhabditis sp. SA1, Phasmarhabditis sp. SA2, Caenorhabditis elegans, Panagrolaimus sp. and Rhabditis sp. Of these species, four were thought to be parasitic to slugs (A. flexilis, Angiostoma sp., Phasmarhabditis sp. SA1 and Phasmarhabditis sp. SA2), as opposed to forming necromenic or phoretic associations. Three new species of slug-parasitic nematode were identified during this study (Angiostoma sp., Phasmarhabditis sp. SA1 and Phasmarhabditis sp. SA2).

Kanzaki N et al. (2012) J Nematol "Two New Species of Pristionchus (Rhabditida: Diplogastridae): P. fissidentatus n. sp. from Nepal and La Reunion Island and P. elegans n. sp. from Japan."

Ragsdale EJ, Herrmann M, Kanzaki N, Sommer RJ

[J Nematol, 2012]

Pristionchus fissidentatus n. sp., isolated from soil in Nepal, and n. sp., isolated from (Coleoptera: Scarabaeidae) in Japan, are described. The two new species are recognized as basal within the genus and thus occupy an important position for macroevolutionary studies that center on the model . n. sp. is distinguished by its unique stegostomatal morphology: in the stenostomatous form, the right subventral ridge has three prominent cusps and the left subventral sector has, in addition to a plate with two cusps, a prominent denticle slightly left of ventral; in the eurystomatous form, the right subventral stegostomatal sector shows both a tooth and a ridge with several cusps. Diagnostic of n. sp. is the structure of the stenostomatous cheilostom, which bulges medially and is underlain by a large vacuolated ring. No eurystomatous form has been observed in n. sp. Reproductive modes of n. sp. and n. sp. are hermaphroditic and gonochoristic, respectively. The additional isolation of n. sp. from soil and two species of scarab beetle on La Reunion Island in the Indian Ocean suggests a broad geographic range for this species.

Wheeler D et al. (2012) J Nematol "Several Grassland Soil Nematode Species Are Insensitive to RNA-Mediated Interference."

Todd TC, Darby BJ, Herman MA, Wheeler D

[J Nematol, 2012]

Phenotypic analysis of defects caused by RNA mediated interference (RNAi) in has proven to be a powerful tool for determining gene function. In this study we investigated the effectiveness of RNAi in four non-model grassland soil nematodes, sp FVV-2., sp, sp., and sp. In contrast to reference experiments performed using and , feeding bacteria expressing dsRNA and injecting dsRNA into the gonad did not produce the expected RNAi knockdown phenotypes in any of the grassland nematodes. Quantitative reverse-transcribed PCR (qRT-PCR) assays did not detect a statistically significant reduction in the mRNA levels of endogenous genes targeted by RNAi in sp., and sp. From these studies we conclude that due to low effectiveness and inconsistent reproducibility, RNAi knockdown phenotypes in non- nematodes should be interpreted cautiously.

Sudhaus W (1974) Zool. Jb. Syst. Bd. "Zur Systematik, Verbreitung, Okologie und Biologie neuer und wenig bekannter Rhabditiden (Nematoda) 2. Teil."

Sudhaus W

[Zool. Jb. Syst. Bd., 1974]

Five new species of the genus Rhabditis are described (Rh. riemanni n. sp., Rh. remanei n. sp., Rh. reciproca n. sp., Rh. blumi n. sp., and Rh. valida n. sp.) belonging to five subgenera (Crustorhabditis, Caenorhabditis, Rhabditis, Cephaloboides, and Pellioditis). The descriptions of four additional species are revised (Rh. ocypodis Chitwood, Rh. scanica Allgen, Rh. plicata Volk, and Rh. bengalensis Timm). The new subgenus Crustorhabditis n. subgen. derives from the paraphyletic subgenus Mesorhabditis. The species of the former group show a transition from living in littoral seaweed deposits to an obligate association with amphibious crabs (Crustacea). Information about the distribution, ecology, biology and ethology of all these species is presented (with two distribution maps, one for Rh. marina for comparison). Supplementary notes are given from Protorhabditis oxyuroides Sudhaus and Rhabditis tripartita von Linstow.

Huang RE et al. (2014) PLoS One "Description of Caenorhabditis sinica sp. n. (Nematoda: Rhabditidae), a nematode species used in comparative biology for C. elegans."

Ren X, Zhao Z, Huang RE, Qiu Y

[PLoS One, 2014]

We re-isolated in China a relative of the nematode model Caenorhabditis elegans that was previously referred to informally as C. sp. 5. In spite of its importance for comparative biology, C. sp. 5 has remained morphologically uncharacterized. Therefore, we now provide detailed description of morphology and anatomy, assigning the name of Caenorhabditis sinica sp. n. to this nematode that is found frequently in China. C. sinica sp. n. belongs to the Elegans group in the genus Caenorhabditis, being phylogenetically close to C. briggsae although differing in reproductive mode. The gonochoristic C. sinica sp. n. displays two significantly larger distal parts of uteri filled with sperms in the female/hermaphroditic gonad than does the androdioecious C. briggsae. The new species can be differentiated morphologically from all known Caenorhabditis species within the Elegans group by presenting a uniquely shaped, three-pointed hook structure on the male precloacal lip. The lateral field of C. sinica sp. n. is marked by three ridges that are flanked by two additional incisures, sometimes appearing as five ridges in total. This study ends the prolonged period of the 'undescribed' anonymity for C. sinica sp. n. since its discovery and use in comparative biological research. Significant and crossing-direction dependent hybrid incompatibilities in F1 and F2 crossing progeny make C. sinica sp. n. an excellent model for studies of population and speciation genetics. The abundance of nematode species lacking detailed taxonomic characterization deserves renewed attention to address the species description gap for this important yet morphologically 'difficult' group of animals.

Worthy SE et al. (2018) PLoS One "Identification of attractive odorants released by preferred bacterial food found in the natural habitats of C. elegans."

Chung K, Ota R, Haynes L, Kan E, Bethune D, Taylor CJ, Worthy SE, Glater EE, Chambers M

[PLoS One, 2018]

Food choice is critical for survival because organisms must choose food that is edible and nutritious and avoid pathogenic food. Many organisms, including the nematode C. elegans, use olfaction to detect and distinguish among food sources. C. elegans exhibits innate preferences for the odors of different bacterial species. However, little is known about the preferences of C. elegans for bacterial strains isolated from their natural environment as well as the attractive volatile compounds released by preferred natural bacteria isolates. We tested food odor preferences of C. elegans for non-pathogenic bacteria found in their natural habitats. We found that C. elegans showed a preference for the odor of six of the eight tested bacterial isolates over its standard food source, E. coli HB101. Using solid-phase microextraction and gas chromatography coupled with mass spectrometry, we found that four of six attractive bacterial isolates (Alcaligenes sp. JUb4, Providenica sp. JUb5, Providencia sp. JUb39, and Flavobacteria sp. JUb43) released isoamyl alcohol, a well-studied C. elegans attractant, while both non-attractive isolates (Raoultella sp. JUb38 and Acinetobacter sp. JUb68) released very low or non-detectable amounts of isoamyl alcohol. In conclusion, we find that isoamyl alcohol is likely an ethologically relevant odor that is released by some attractive bacterial isolates in the natural environment of C. elegans.