Troemel ER et al. (1997) Cell "Reprogramming chemotaxis responses: sensory neurons define olfactory preferences in C. elegans."

Bargmann CI, Troemel ER, Kimmel BE

[Cell, 1997]

Different olfactory cues elicit distinct behaviors such as attraction, avoidance, feeding, or mating. In the nematode C. elegans, these cues are sensed by a small number of olfactory neurons, each of which expresses several different odorant receptors. The type of behavioral response elicited by an odorant could be specified by the olfactory receptor or by the olfactory neuron in which the receptor is activated. The attractive odorant diacetyl is detected by the receptor protein ODR-10, which is normally expressed in the AWA olfactory neurons. The repulsive odorant 2-nonanone is detected by the AWB olfactory neurons. Transgenic animals that express ODR-10 in AWB rather than AWA avoid diacetyl, while maintaining qualitatively normal responses to other attractive and repulsive odorants. Animals that express ODR-10 simultaneously in AWA and AWB have a defective response to diacetyl, possibly because of conflicting olfactory inputs. Thus, an animal's preference for an odor is defined by the sensory neurons that express a given odorant receptor molecule.

Sengupta P et al. (1993) Ciba Foundation Symposium "The cellular and genetic basis of olfactory responses in Caenorhabditis elegans."

Dwyer ND, Sengupta P, Bargmann CI, Kimmel BE, Colbert HA

[Ciba Foundation Symposium, 1993]

The small soil nematode Caenorhabditis elegans has only 302 neurons in its entire nervous system, so it is possible to analyse the functions of individual neurons in the animal's behaviour. We are using behavioural, cellular and genetic analyses of chemotactic responses to find out how olfactory behaviour patterns are generated and regulated. Single chemosensory neurons in C. elegans can recognize several different attractive odorants that are distinguished by the animal. Distinct sets of chemosensory neurons detect high and low concentrations of a single odorant. Odorant responses adapt after prolonged exposure to an odorant; this adaptation is odorant specific and reversible. Mutants with defects in odorant responses have been identified. Some genes appear to be necessary for the development or function of particular kinds of sensory neurons. Other genes have effects that suggest that they participate in odorant reception or signal transduction.

Dusenbery DB (1985) Comput Biol Med "Using a microcomputer and video camera to simultaneously track 25 animals."

Dusenbery DB

[Comput Biol Med, 1985]

A system that can simultaneously track about 25 animals with the position of each determined once a second is described. The system includes a 6809 microprocessor, OS-9 operating system and application programs written in assembly and BASIC09. The movements and changes in direction of the subjects can be determined and displayed in real time. The system has proven to be valuable in studying the chemotaxis of nematodes and should be applicable to the study of other animals that can be viewed

Jansen G et al. (1997) Nat Genet "Reverse genetics by chemical mutagenesis in Caenorhabditis elegans."

Thijssen KL, Plasterk RHA, Hazendonk E, Jansen G

[Nat Genet, 1997]

Traditional reverse genetics on yeast, mice and other organisms uses homologous recombination with transgenic DNA to interrupt a target gene. Here we report that target-selected gene inactivation can be be achieved in Caenorhabditis elegans with the use of chemical mutagens. We use PCR to selectively visualize deletions in genes of interest; the method is sensitive enough to permit detection of a single mutant among more than 15,000 wild types. A permanent frozen mutant collection of more than a million mutagenized animals has been established, and deletion mutants of several G-protein genes were isolated from it. The approach is suitable to be scaled up for systematic inactivation of all 17,000 C. elegans genes. Because it requires no transgenesis or cell culturing, it may also be applicable to small organisms usually considered to be outside the realm of reverse genetics (for example, other nematodes and insects). Any sequenced gene in any organism that can be handled in very large numbers can possibly be targeted in this way.

Wang D et al. (2008) Environ Pollut "Nickel sulfate induces numerous defects in Caenorhabditis elegans that can also be transferred to progeny."

Wang D, Wang Y

[Environ Pollut, 2008]

Whether the multiple biological toxicities from nickel exposure could be transferred to progeny has not been clarified. In this report, we explored the Caenorhabditis elegans to analyze the multiple toxicities of nickel and their possibly transferable properties. The nickel toxicity caused multiple biological defects in a concentration-dependent manner. Moreover, most of these toxicities could be transferred and could be only partially rescued in progeny. Some specific phenotypes in progeny were also found to exhibit no obvious rescue phenotypes or to show even more severe defects than their parents. The defects caused by nickel exposure could be classified into four groups according to their transferring properties. That is, the defects caused by nickel exposure could be largely, or partially, or unable to be rescued, or became even more severe in progeny animals. Therefore, most of the nickel exposure-caused defects can be transferred from parents to their progeny to different degrees in C. elegans.

Buecher EJ et al. (1969) Experientia "Yeast extract as a supplement to chemically defined medium for axenic culture of Caenorhabditis briggsae"

Hansen EL, Buecher EJ

[Experientia, 1969]

Caenorhabditis briggsae, a free living soil nematode, can be grown axenically in a chemically defined medium if this is supplemented with proteinaceous materials. Only a few such materials, derived from chick embryo, bacteria, and liver have been found to be effective supplements. Since yeast cultures on agar support nematodes in vitro it seemed probable that an effective supplement could also be made from extracts of yeast.

Liao LW et al. (1983) Nucleic Acids Res "Target sequences for the C. elegans transposable element Tc1."

Liao LW, Rosenzweig WD, Hirsh DI

[Nucleic Acids Res, 1983]

The target sequences for two independent insertions of the transposable element Tc1 from Caenorhabditis elegans show homology. Because both insertions are at palindromic TA/AT sequences, the exact boundaries of Tc1 cannot be distinguished; Tc1 could be 1610 bp and flanked by a 2-bp duplication of the target site or it could be 1612 bp and without target site duplication. The latter possibility implies a novel manner for insertion of a transposable element.

Dieterich C et al. (2007) Nucleic Acids Res "Pristionchus.org: a genome-centric database of the nematode satellite species Pristionchus pacificus."

Sommer RJ, Dieterich C, Sobetzko P, Roeseler W

[Nucleic Acids Res, 2007]

Comparative studies have been of invaluable importance to the understanding of evolutionary biology. The evolution of developmental programs can be studied in nematodes at a single cell resolution given their fixed cell lineage. We have established Pristionchus pacificus as a major satellite organism for evolutionary developmental biology relative to Caenorhabditis elegans, the model nematode. Online genomic information to support studies in this satellite system can be accessed at http://www.pristionchus.org. Our web resource offers diverse content covering genome browsing, genetic and physical maps, similarity searches, a community platform and assembly details. Content will be continuously improved as we annotate the P.pacificus genome, and will be an indispensable resource for P.pacificus genomics.

Seung HS (2009) Neuron "Reading the book of memory: sparse sampling versus dense mapping of connectomes."

Seung HS

[Neuron, 2009]

Many theories of neural networks assume rules of connection between pairs of neurons that are based on their cell types or functional properties. It is finally becoming feasible to test such pairwise models of connectivity, due to emerging advances in neuroanatomical techniques. One method will be to measure the functional properties of connected pairs of neurons, sparsely sampling pairs from many specimens. Another method will be to find a "connectome," a dense map of all connections in a single specimen, and infer functional properties of neurons through computational analysis. For the latter method, the most exciting prospect would be to decode the memories that are hypothesized to be stored in connectomes.

Emerson F et al. (2020) Elife "A memory of longevity."

Lee SS, Li CL, Emerson F

[Elife, 2020]

Worms with increased levels of the epigenetic mark H3K9me2 have a longer lifespan that can be passed down to future generations.