Scott SP et al. (2000) European Worm Meeting "Starvation stress and trade-offs in C. elegans"

Lithgow GJ, Scott SP, Jenkins NL, McColl G, Walker DW

[European Worm Meeting, 2000]

Ageing has been postulated to result from late life detrimental effects of genes that act beneficially early in life. Evidence to support this hypothesis has been provided by the competitive fitness of a single-gene mutant in Caenorhabditis elegans that increases mean and maximum lifespan by up to 80%. The gene, age-1, encodes a phosphatidylinositol 3-kinase catalytic subunit that functions in an insulin-like signalling pathway. This pathway controls progression through normal development and determines adult stress resistance. Under standard laboratory conditions there are no apparent costs associated with the age-1(hx546) mutation. However, a trade-off between longevity and competitive fitness was observed under conditions of cyclical starvation that approximate the natural environment and hence have greater relevance to the evolutionary history of C. elegans. Further investigation indicates that the length of starvation period affects which life stages contribute to subsequent generations and, unexpectedly, it is young adults rather than dauers in which the trade-off occurs. Examination of dauers of both age-1 and wild type strains after starvation indicates that, in contrast to current belief, there are costs associated with this life stage.

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.

Zhao C et al. (1993) Worm Breeder's Gazette "Cloning of the lin-32 Gene"

Emmons SW, Zhao C

[Worm Breeder's Gazette, 1993]

Cloning of the lin-32 gene Connie Zhao and Scott W. Emmons, Department of Molecular Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461

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.

Woodruff, Gavin et al. (2015) International Worm Meeting "Notable characteristics of Caenorhabditis sp. 34, a novel species associated with figs."

Kanzaki, Natsumi, Woodruff, Gavin, Kikuchi, Taisei

[International Worm Meeting, 2015]

In 2013, a novel nematode species was discovered in the fresh figs of Ficus septica in Okinawa. Subsequent DNA sequencing revealed that this species belongs to Caenorhabditis. Here, some biological characteristics of C. sp. 34 are described. C. sp. 34 is an exceptional member of Caenorhabditis in a number of respects. C. sp. 34 animals can grow to be nearly twice as long as C. elegans (1.5-2 mm), and take about twice as long to develop (~8 days at 20degC). This length difference in adults is largely due to post-embryonic events as C. sp. 34 embryos are about 19% longer than C. elegans embryos. C. sp. 34 sperm are enormous (about three times longer in diameter than C. elegans sperm), whereas the C. sp. 34 female tail spike is about half as long as that of the C. elegans hermaphrodite. However, examination of Hoechst-stained diakinesis oocytes reveals that, like C. elegans, C. sp. 34 has six chromosomes. No differences in the number of intestinal nuclei were observed between C. sp. 34 and C. elegans. Preliminary fluorescent microscopy observations suggest that the somatic nucleus number, hypodermal nucleus ploidy, and genome size of C. sp. 34 is comparable to that of other Caenorhabditis species. Additionally, mating tests show that C. sp. 34, C. sp. 35 (which is also fig-associated), and C. elegans are distinct biological species, and reproductive barriers include lack of sperm transfer, lack of fertilization, and embryonic inviability. This work has been concurrent with a larger collaborative effort, whose ongoing efforts include investigations into genomics, population genetics, and developmental biology. C. sp. 34 is an exciting species that will likely prove fruitful in future evolutionary studies.

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.

Blaxter, Mark et al. (2015) International Worm Meeting "The Caenorhabditis Genomes Project."

Koutsovoulos, Georgios, Chandrasekar, Sinduja, Stevens, Lewis, Blaxter, Mark

[International Worm Meeting, 2015]

The sequencing of the genome of Caenorhabditis elegans remains one of the milestones of modern biology, and this genome sequence is the essential backdrop to a vast body of work on this key model organism. "Nothing in biology makes sense except in the light of evolution" (Dobzhansky) and thus it is clear that complete understanding of C. elegans will only be achieved when it is placed in an evolutionary context. While several additional Caenorhabditis genomes have been published or made available, a recent surge in the number of available species in culture makes the determination of the genomes of all the species in the genus a timely and rewarding project.We have initiated the Caenorhabditis Genomes Project. From material supplied by collaborators we have so far generated raw Illumina short-insert data for sixteen species. Where possible we have also generated mixed stage stranded RNASeq data for annotation. The data are being made publicly available as early as possible (warts-and-all) through a dedicated genome website at htttp://caenorhabditis.bio.ed.ac.uk, and completed genomes and annotations will be deposited in WormBase as mature assemblies emerge. We welcome additional collaborators to the CGP, whether to assemble new genomes or to delve into the evolutionary history of favourite gene sets and systems.Species sequenced thus far in Edinburgh: Caenorhabditis afra, Caenorhabditis castelli, Caenorhabditis doughertyi, Caenorhabditis guadeloupensis, Caenorhabditis macrosperma, Caenorhabditis nouraguensis, Caenorhabditis plicata, Caenorhabditis virilis, Caenorhabditis wallacei, Caenorhabditis sp. 1, Caenorhabditis sp. 5, Caenorhabditis sp. 21, Caenorhabditis sp. 26, Caenorhabditis sp. 31, Caenorhabditis sp. 32, Caenorhabditis sp. 38, Caenorhabditis sp. 39, Caenorhabditis sp. 40, Caenorhabditis sp. 43.[Samples have been supplied by Aurelien Richaud, Marie-Anne Felix, Christian Braendle, Michael Alion, Piero Lamelza].

Townsend SR et al. (1994) Worm Breeder's Gazette "C. elegans Molecular Genetics and Long PCR."

Finelli AL, Savage C, Xie T, Padgett RW, Townsend SR

[Worm Breeder's Gazette, 1994]

C. elegans Molecular Genetics and Long PCR Scott R. Townsend, Cathy Savage, Alyce L. Finelli, Ting Xie, and Richard W. Padgett, Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08855

Kimble JE et al. (2000) Midwest Worm Meeting "Genetics of prepattern formation in the C. elegans gonad"

Siegfried KR, Kimble JE

[Midwest Worm Meeting, 2000]

During organ development many tissue types must be specified and organized to form a functional organ. We are interested in how the different tissues that comprise an organ become organized. To address this problem, we have taken a genetic approach to identify genes that are required for patterning the somatic gonadal tissues in C. elegans. During early gonadogenesis, blast cells and regulatory cells are specified. Subsequently, somatic gonadal blast cells rearrange to set up the pattern of the adult organ. This "prepattern" of the adult tissues is called the somatic primordium (SP). In both hermaphrodites and males, SP formation is crucial for proper organization of the gonadal tissues. The SP differs between sexes reflecting the dimorphic organization of tissues seen in adult gonads. We have isolated a group of mutants in which SP formation is disrupted in a sex-specific manner. In hermaphrodites, the early somatic gonadal lineage is aberrant and the SP fails to form. This failure in SP formation results in a severely disorganized organ and sterility. In males, however, the early lineage is normal and SP formation is not affected. We postulate that, during early gonadogenesis, cells required for instructing hermaphrodite SP formation are not specified. We have identified seven genes with this mutant phenotype. These genes show dose sensitivity and appear to define a developmental pathway. We are in the process of characterizing these mutants genetically, phenotypically and molecularly to understand how the somatic gonadal tissues are patterned during organogenesis.