Salser SJ et al. (1994) Worm Breeder's Gazette "mab-5 Expression Repeatedly Switches ON and OFF in the V5 Lineage"

Kenyon CJ, Salser SJ

[Worm Breeder's Gazette, 1994]

mab-5 Expression Repeatedly Switches ON and OFF in the V5 Lineage S. Salser and C. Kenvon, UCSF, San Francisco, CA. 94143

Mata-Cabana, Alejandro et al. (2021) International Worm Meeting "Differential regulation of developmental stages supports a linear model for C. elegans postembryonic development."

Piubeli, Francine Amaral, Romero-Exposito, Francisco Javier, Olmedo, Maria, Merrow, Martha, Mata-Cabana, Alejandro, Geibel, Mirjam

[International Worm Meeting, 2021]

During C. elegans postembryonic development, each of the four larval stages entails a process of feeding, a period of quiescence, and ecdysis. The repetitive nature of this process resembles oscillatory process as circadian rhythms. Nevertheless, each larval stage has a defined duration and entails specific events. A central question remains as to whether the overall speed of postembryonic development is controlled by a timer that affects all larval stages equally, as opposed to a linear process, where progression of development is achieved by the completion of stage specific events. The perturbation of a regulator of developmental timing would yield slower or faster animals, with larval stages that scale proportionally to the duration of total development. Contrarily, if development proceeds in a linear manner, based on completing stage-specific events, perturbations that affect overall duration of development might have different impact on different stages, depending on the specific events that take place during each stage. The answer to this question calls for precise quantification of postembryonic development in response to varied perturbations that alter overall developmental timing. We have measured the duration of each stage of larval development for over 2,500 larvae, upon perturbations in temperature, in food quantity and quality, and amount of insulin signaling. Importantly, the assay we used monitors development continuously, with a time resolution of five minutes, and resolves the transitions between molts and intermolts. We observed that interventions that alter developmental timing have a differential effect on the discrete stages of larval development. Furthermore, our high-resolution measurement of the effect of temperature has unveiled characteristic features of temperature dependence in C. elegans postembryonic development. Altogether, our results support a mechanism based on a linear progression of postembryonic development, where the events that take place in each stage are differentially impacted by environmental perturbations.

Kenyon CJ et al. (1994) Worm Breeder's Gazette "Activity of the polyray-1 Maintenance Gene Must Be Overcome To Allow For Correct Temporal Expression of HOM-C Genes"

Kenyon CJ, Maloof JN

[Worm Breeder's Gazette, 1994]

Activity of the polyray-1 maintenance gene must be overcome to allow for correct temporal expression of HOM-C genes Julin Maloof and Cynthia Kenyon, Dept of Biochemistry, UCSF, San Francisco, CA 94143 0554

Apfeld J et al. (1996) West Coast Worm Meeting "A GENETIC SCREEN FOR LONG-LIVED WORMS."

Hsin H, Dorman JB, Kenyon CJ, Apfeld J, Albinder B

[West Coast Worm Meeting, 1996]

We are interested in finding genes that control lifespan in C. elegans. We are currently doing a clonal screen for mutations that lead to an increase in lifespan. We mutagenize a temperature-sensitive sterile strain, clone out F2 progeny, allow these worms to self fertilize, clone some of their progeny into a new plate at the restrictive temperature, and screen these for increased lifespan. So far we have screened 360 F2 clones and are in the process of retesting 3 of them. Javier Apfeld is also studying the gene daf-2. The e1370 allele of this gene has multiple phenotypes: at 25°C daf-2(e1370) worms develop into dauer larvae (a developmentally arrested, stress resistant, long lived alternative larval form); at 20°C daf-2(e1370) worms do not form dauer larvae, but live 2.5 times longer than wild-type (N2) worms. Javier wants to know where daf-2 functions and how it acts, and is currently doing mosaic analysis to address these questions.

Robertson FM (2010) IDrugs "High-Content Analysis--CHI's Seventh Annual Conference--Developments in HCA and Pathway Analysis."

Robertson FM

[IDrugs, 2010]

CHI''s Seventh Annual Conference on High-Content Analysis (HCA), held in San Francisco, incorporated topics covering new developments in the field of HCA, including hardware and software updates, new biological models for HCA and pathway analysis. This conference report highlights selected presentations on the use of HCA for the characterization of stem cells, cell-colony analysis, the validation of disease models and the identification of antiparasitic compounds.

Gogonea CB et al. (1999) J Mol Graph Model "Computational prediction of the three-dimensional structures for the Caenorhabditis elegans tubulin family."

Ali YM, Gogonea V, Merz KM, Gogonea CB, Siddiqui SS

[J Mol Graph Model, 1999]

In this article we characterize, from a structural point of view, all 16 members of the tubulin gene family of Caenorhabditis elegans (9 alpha-tubulins, 6 beta-tubulins, and 1 gamma-tubulin). We obtained their tertiary structures by computationally modifying the X-ray crystal structure of the pig brain alpha/beta-tubulin dimer published by Nogales et al. [Nature (London) 1998;391:199-203]. Our computational protocol involves changing the amino acids (with MIDAS; Jarvis et al., UCSF MIDAS. University of California, San Francisco, 1986) in the 3D structure of pig brain alpha/beta-tubulin dimer followed by geometry optimization with the AMBER force field (Perlman et al., AMBER 4. University of California, San Francisco, 1990). We subsequently analyze and compare the resulting structures in terms of the differences in their secondary and tertiary structures. In addition, we compare the pattern of hydrogen bonds and hydrophobic contacts in the guanosine triphosphate (GTP)-binding site for all members of the tubulin family. Our computational results show that, except for gamma-tubulin, all members of the C. elegans tubulin family have similar secondary and 3D structures and that the change in the pattern of hydrogen bonds in the GTP-binding site may be used to assess the relative stability of different alpha/beta-tubulin dimers formed by monomers of the tubulin family.

Apfeld J et al. (1999) Nature "Regulation of lifespan by sensory perception in Caenorhabditis elegans."

Kenyon CJ, Apfeld J

[Nature, 1999]

Caenorhabditis elegans senses environmental signals through ciliated sensory neurons located primarily in sensory organs in the head and tail. Cilia function as sensory receptors, and mutants with defective sensory cilia have impaired sensory perception. Cilia are membrane-bound microtubule-based structures and in C. elegans are only found at the dendritic endings of sensory neurons. Here we show that mutations that cause defects in sensory cilia or their support cells, or in sensory signal transduction, extend lifespan. Our findings imply that sensory perception regulates the lifespan of this animal, and suggest that in nature, its lifespan may be regulated by environmental cues.AD - Department of Biochemistry and Biophysics, University of California at San Francisco, 94143-0448, USA.FAU - Apfeld, JAU - Apfeld JFAU - Kenyon, CAU - Kenyon CLA - engPT - Journal ArticleCY - ENGLANDTA - NatureJID - 0410462RN - 0 (DAF-16 transcription factor)RN - 0 (DAF-2 protein)RN - 0 (Helminth Proteins)RN - 0 (Transcription Factors)RN - EC 2.7.11.- (Receptor, Insulin)SB - IM

Ellis HM et al. (1983) Worm Breeder's Gazette "monoclonal antibodies directed against the Drosophila nervous system cross-react with C elegans."

Yuan JY, Horvitz HR, Ellis HM

[Worm Breeder's Gazette, 1983]

We have begun to screen a collection of monoclonal antibodies that were generated against Drosophila embryos and stain a variety of Drosophila nervous tissues. These antibodies were kindly provided by Lily and Yuh Nung Jan of the University of California at San Francisco. Worms were fixed overnight at 4 C in 2% Formaldehyde, squashed, frozen and fractured as described by Albertson et al. (W.B.G. Vol.7 No.1) and transferred through a series of alchohols (95,70,50% EtOH). Three out of nine monoclonal antibodies that we have tested so far stain C. elegans. 20B6-B6* stains many nerve processes including dorsal and ventral cords, sub-lateral cords, cord commissures, amphid commissures and processes in the head. It is not yet clear whether this antibody stains all or only some processes. 18H12-C3* stains processes in a manner similar to 20B6-B6* as well as sperm and muscle ( or a structure with a muscle-like staining pattern). 21A4-E4 stains sperm and early (pre-morphogenetic) eggs. This staining is non- nuclear in both sperm and eggs and appears to be symmetrically distributed within eggs.

De Bono M et al. (1998) Cell "Natural variation in a neuropeptide Y receptor homolog modifies social behavior and food response in C. elegans."

Bargmann CI, De Bono M

[Cell, 1998]

Natural isolates of C. elegans exhibit either solitary or social feeding behavior. Solitary foragers move slowly on a bacterial lawn and disperse across it, while social foragers move rapidly on bacteria and aggregate together. A loss-of-function mutation in the npr-1 gene, which encodes a predicted G protein-coupled receptor similar to neuropeptide Y receptors, causes a solitary strain to take on social behavior. Two isoforms of NPR-1 that differ at a single residue occur in the wild. One isoform, NPR-1 215F, is found exclusively in social strains, while the other isoform, NPR-1 215V, is found exclusively in solitary strains. An NPR-1 215V transgene can induce solitary feeding behavior in a wild social strain. Thus, isoforms of a putative neuropeptide receptor generate natural variation in C. elegans feeding behavior.AD - Howard Hughes Medical Institute, Department of Anatomy, The University of California, San Francisco 94143-0452, USA.FAU - de Bono, MAU - de Bono MFAU - Bargmann, C IAU - Bargmann CILA - engSI - GENBANK/U49944PT - Journal ArticleCY - UNITED STATESTA - CellJID - 0413066RN - 0 (Helminth Proteins)RN - 0 (Receptors, Neuropeptide Y)RN - EC 3.6.1.- (GTP-Binding Proteins)SB - IM

L'Etoile ND et al. (2000) Neuron "Olfaction and odor discrimination are mediated by the C. elegans guanylyl cyclase ODR-1."

L'Etoile ND, Bargmann CI

[Neuron, 2000]

Animals in complex environments must discriminate between salient and uninformative sensory cues. Caenorhabditis elegans uses one pair of olfactory neurons called AWC to sense many different odorants, yet the animal can distinguish each odorant from the others in discrimination assays. We demonstrate that the transmembrane guanylyl cyclase ODR-1 is essential for responses to all AWC-sensed odorants. ODR-1 appears to be a shared signaling component downstream of odorant receptors. Overexpression of ODR-1 protein indicates that ODR-1 can influence odor discrimination and adaptation as well as olfaction. Adaptation to one odorant, butanone, is disrupted by ODR-1 overexpression. Olfactory discrimination is also disrupted by ODR-1 overexpression, probably by overproduction of the shared second messenger cGMP. We propose that AWC odorant signaling pathways are insulated to permit odor discrimination.AD - Howard Hughes Medical Institute, Department of Anatomy, University of California, San Francisco 94143, USA.FAU - L'Etoile, N DAU - L'Etoile NDFAU - Bargmann, C IAU - Bargmann CILA - engSI - GENBANK/AF235027PT - Journal ArticleCY - UNITED STATESTA - NeuronJID - 8809320RN - 0 (Benzaldehydes)RN - 0 (Butanones)RN - 0 (Galpha protein ODR-3)RN - 0 (Pentanols)RN - 0 (Receptors, Odorant)RN - 123-51-3 (isopentyl alcohol)RN - EC 3.6.1.- (Heterotrimeric GTP-Binding Proteins)RN - EC 4.6.1.2 (Guanylate Cyclase)SB - IM