Allyson J Whittaker et al. (2002) West Coast Worm Meeting "Characterization of the early steps of male mating behavior of C. elegans"

Gary Schindelman, Allyson J Whittaker, Shahla Gharib

[West Coast Worm Meeting, 2002]

The mutation cod-5 was previously isolated in our lab in a screen for lines with reduced mating efficiency. We found that in addition to having strong turning defects,cod-5 mutants are also defective in response and vulval location. Cloning of cod-5, is in progress.

Burglin TR et al. (1995) International C. elegans Meeting "MOLECULAR AND GENETIC ANALYSIS OF THE POU-HOMEOBOX GENE ceh-6."

Burglin TR, Ruvkun GB

[International C. elegans Meeting, 1995]

ceh-6 is a member of the POU-III homeobox gene family. Antibodies against a CEH-6 protein and transgenic animals carrying a ceh-6-promotor-lacZ fusion gene showed that ceh-6 is expressed in 8 bilaterally symmetric neurons in the brain (RMDD, RMDV, AUA, AVH), the SABVs, and the excretory cell. The antibodies further showed expression in the Pn.a neuroblasts in the ventral nerve cord, expression in 2 pairs of bilaterally symmetric cells in the vulva, and the Y, K, F, B, U cells in the rectum. At later stages a 6th cell stains in the rectum (probably P12.pa). In males additional cells in the tail stain. This complex expression pattern is similar to the vertebrate orthologues which are expressed in different tissues in the brain, the spinal cord, and kidney tubules.

Adriana La Volpe et al. (2002) European Worm Meeting "rad-51 gene in meiosis and in soma"

Cinzia Rinaldo, Sara Ederle, Adriana La Volpe, Massimo Hilliard, Paolo Bazzicalupo

[European Worm Meeting, 2002]

We have analyzed in detail the effects of rad-51 RNAi in several genetic backgrounds in order to dissect the pathways in which rad-51 is involved in C. elegans in the germline and to establish the role of this gene in the somatic cells. We have verified that the high levels of embryonic lethality are due to maternal effect. We have explored the effect of rad-51 RNAi in mutants lacking fundamental components of the recombination machinery and postulated roles for such protein and for RAD-51 during meiosis. Silencing of the rad-51 gene also causes a reduction in fecundity, which is suppressed by mutation in the DNA damage checkpoint gene rad-5, but not in the cell death effector gene ced- 3. Finally, RAD-51 depletion is also seen to affect the soma, resulting in hypersensitivity to ionizing radiation in late embryogenesis.

Mark Steciuk et al. (2002) West Coast Worm Meeting "Evolution of Nematode Feeding Behavior"

Mark Steciuk, Boris Shtonda, Leon Avery

[West Coast Worm Meeting, 2002]

Different nematodes live in different environments and therefore must employ different feeding behaviors in order to be successful. Feeding behavior is controlled by the pharyngeal nervous system, which although structurally similar in a variety of nematodes, directs a variety of behaviors across different species. C. elegans and P. redivivus differ in that the terminal bulb of P. redivivus is capable of pumping independently of the corpus, while in C. elegans these two compartments always pump synchronously. Despite this difference, the nervous systems of these two nematodes are conserved at the structural (by Nomarski optics), chemical (by antibody staining), and functional levels. In all cases to date the function of neurons in P. redivivus can be explained by their connectivity in C. elegans. Laser ablation of MC in P. redivivus and C. elegans results in a decreased rate of corpus pumping. In this case, the function of MC is the same in both species. In C. elegans the motor neuron M2 has synapses on the isthmus but has no detectable function. In P. redivivus and a related species, ablation of M2 causes a growth rate defect, apparently due to a defect in isthmus peristalsis. Thus in this case, the function in P. redivivus is consistent with the connectivity in C. elegans. In C. elegans the motor neuron M4 synapses on the isthmus and the terminal bulb, functioning to control isthmus peristalsis. In P. redivivus, M4 does not appear to play an important role in isthmus peristalsis, but rather is necessary for independent terminal bulb pumping. Again, the function in P. redivivus is consistent with the connectivity in C. elegans.

Woldemariam, Sarah et al. (2017) International Worm Meeting "Robust and sensitive cGMP sensor for real time imaging of intact C. elegans."

Li, Joy, Shankar, Raakhee, VanHoven, Miri, Gottschalk, Alexander, L'Etoile, Noelle, Nagpal, Jatin, Krzyzanowski, Michelle, Barsi-Rhyne, Benjamin, Futey, Mary, Tran, Alan, Yu, Yanxun, Ferkey, Denise, Sengupta, Piali, Woldemariam, Sarah

[International Worm Meeting, 2017]

cGMP is a ubiquitous second messenger implicated in many important biological processes. In neurons, cGMP dynamics can regulate the function of ion channels and kinases, resulting in physiological changes. In order to understand how cGMP dynamics in neurons are modulated, we need a tool to visualize cGMP. To this end, we are characterizing a EGFP based cGMP sensor codon optimized for use in C. elegans that will allow us to image cGMP dynamics in neurons in the living behaving animal. We measured its kinetics by coexpressing the sensor with the optogenetic guanylyl cyclase BeCyclOp in body wall muscle and measured its dynamics in response to numerous stimuli, including changing ion concentrations, noxious stimuli and temperature.

Willett JD et al. (1991) International C. elegans Meeting "SEROTONIN AND AGING IN CAENORHABDITIS ELEGANS."

Madan S, Oates KK, Willett JD, Hong C, Zuckerman BM

[International C. elegans Meeting, 1991]

Alterations in neuroendocrine function are fundamental to altered physiological responses to stimuli observed in aging organisms. In mammalian systems the neurotransmitter serotonin declines in the senescent central nervous system. Such changes are believed relevant to functional declines in learning, memory and behavior. Since C. eleqans is an ideal system in which to explore the molecular mechanisms of age-dependent alterations in serotonin levels, studies have been undertaken on serotonin levels throughout the nematode life cycle. While serotonin is present in C. eleqans and 'serotonergic' cells have been identified using immunofluorescent techniques, its functional role in these organisms remains obscure. As in mammalian systems, a decline in serotonin levels in the senescent nematode is observed. We have also found an indolealkylamine of unknown structure present in amounts greater than that of serotonin. This substance appears to be a 5-oxygenated indolealkylamine with a MW of 234. Work is underway to fully characterize this material.

La Volpe A et al. (2000) European Worm Meeting "Promoter regulation of CeRAD51 gene"

Bazzicalupo P, Hilliard MA, Rinaldo C, Ederle S, La Volpe A

[European Worm Meeting, 2000]

RAD51, structurally and functionally related to RecA of Escherichia coli, is a key molecule in DNA damage repair and in meiotic recombination. Mutations in this gene lead in yeast to impaired meiosis, reduction of mitotic recombination and enhanced sensitivity to genotoxic agents (like X- and gamma-radiations) that induce double strand breaks (DSBs) on DNA. To investigate the expression of CeRAD51 we used a promoter fusion with the reporter gene LacZ in one of Andy Fires promoterless vector. Different transgenic lines express the reporter gene in a limited number of cells and of animals. After gamma-irradiation we observed an activation of the RAD51 promoter. The treatment results in an increase in the number of animals expressing the transgene in the population and in an overall enhancement in the expression of the reporter gene LacZ.

Suo, S. et al. (2019) International Worm Meeting "Sexually dimorphic dopaminergic signaling regulates behavioral states of C. elegans."

Matsuda, S., Wang, M., Harada, K., Suo, S., Awaji, T., Kyo, K., Maruyama, K., Tsuboi, T.

[International Worm Meeting, 2019]

C. elegans hermaphrodites switch between two distinct behavioral states, roaming and dwelling, in which animals have high and low locomotor activity, respectively. Hermaphrodites spend most of the time in the dwelling state and various neuromodulators are involved in this regulation. However, the behavioral states of males have yet been studied. In this study, we analyzed sex differences in the behavioral states and found that males spend less time in the low activity state than hermaphrodites on food. In dopamine-deficient cat-2 mutants, the dwelling state was increased in males and, as previously reported, decreased in hermaphrodites compared to the wildtype counterparts, suggesting that dopamine generates the sex differences in the behavioral states by having the opposite effects in males and hermaphrodites. We also found that, in males, dopamine reduces the dwelling state by acting in the same pathway as polycystic kidney disease-related genes, which function exclusively in male-specific neurons. In hermaphrodites, octopamine signaling in the sex-shared SIA neurons promotes locomotion and dopamine increases the dwelling state by suppressing the octopamine signaling. Calcium imaging showed that the SIA neurons of hermaphrodites respond to octopamine by evoking calcium oscillation. In contrast, the calcium response to octopamine was severely reduced in the SIA neurons of males. Furthermore, males explored a larger area of the bacteria lawn than hermaphrodites and dopamine was responsible for this sex difference. In addition, dopamine promotes exploration outside of a lawn in males and suppresses it in hermaphrodites: males leave a lawn at a much higher rate than hermaphrodites in the absence of mates and dopamine was also responsible for this difference. These behavioral differences are beneficial for males to find mates and hermaphrodites to stay with food. Together, the results demonstrate that dopamine controls behavioral states in the opposite way through sexually dimorphic signaling to promote adaptive behavior for each sex.

Jennifer Ramond Berman et al. (2002) West Coast Worm Meeting "An RNAi-based screen for genes involved in the regulation of lifespan by the reproductive system"

Allen Hsu, Cynthia Kenyon, Malene Hansen, Jennifer Ramond Berman, Nuno Arantes-Oliveira, Andrew Dillin

[West Coast Worm Meeting, 2002]

Longevity in C. elegans is mediated through an elaborate coordination of environmental cues and endogenous hormonal control. Within the animal, the reproductive system plays a major role in determining the rate of aging. This is evidenced by experiments in which laser ablation of the germline precursor cells in an L1 results in a 60% extension in mean adult lifespan (1). Intriguingly, this extension is sensitive to the amount of germline proliferation in the adult, implying that in a normal adult worm, lifespan is downregulated in accordance with cues from mitotic germ cells (2). However, signals from the somatic gonad counteract this signal, since ablation of the somatic gonad precursor cells rescues the lifespan extension seen in germline-ablated animals(1).

Ardelle C Stauffer et al. (2002) West Coast Worm Meeting "Extending the unc-53 pathway- Part II: Isolation of genetic suppressors."

Eve G Stringham, Ardelle C Stauffer, Nelvia Van Dorp

[West Coast Worm Meeting, 2002]

Strong hypomorphic alleles of unc-53 display reduced extension and guidance defects in the longitudinal outgrowth of a subset of cells including the ALN and PLN axons, the excretory canals, and the sex muscles, the latter resulting in an egg laying defective phenotype in hermaphrodites. In contrast, overexpression of UNC-53 in muscle cells results in exaggerated outgrowth during embryogenesis. UNC-53 encodes a 1583 amino acid protein that in vitro binds F-actin and SEM-5/GRB2 (Stringham et al., 2002, Development 129: 3367-3379.) suggesting UNC-53 plays a role in both signal transduction and modelling of the actin cytoskeleton. We are interested in identifying additional molecules which operate in the UNC-53 pathway to control longitudinal pathfinding.