Nariya, Hardik et al. (2017) International Worm Meeting "An investigation of the effects of artificial light at night on C. elegans offspring production and lifespan."

Buchanan, Bryant, Wise, Sharon, Zhushma, Rosa, Nariya, Hardik, Shinn-Thomas, Jessica

[International Worm Meeting, 2017]

Artificial light at night (ALAN) has many broad-scale and global implications for ecosystems and wildlife that have evolved under a 24-h circadian cycle. With increased urbanization, artificial light at night has directly altered natural photoperiods and nocturnal light intensity. Artificial light at night can disrupt behavioral patterns such as foraging activity and mating in animals. Disturbances in natural light and dark cycles also affect melatonin-regulated circadian and seasonal rhythms in Drosophila. We investigated the impact of ecologically relevant levels of light pollution on an important invertebrate model, Caenorhabditis elegans, as the impact of night lighting at these light levels is currently unknown. In this study, we exposed worms to artificial light at four intensities: 10-4 lx (control, comparable to natural nocturnal darkness), 10-2 lx (comparable to full-moon lighting and a low level of light pollution), 1 lx (comparable to dawn/dusk or intense light pollution), and 100 lx (dim daylight level comparable to extreme light pollution) on a 12L:12D photoperiod (100 lx treatments experienced constant light). We measured the impact of these light treatments on offspring production in hermaphroditic C. elegans. We grew worms for 2 generations in each light treatment, and then recorded the lifespan and counted the number of hatched offspring produced in the F3 generation. Our data show no significant differences among light levels for lifespan or offspring production suggesting that at least for these life history traits, ALAN does not affect these soil nematodes. Future directions include measuring additional life history traits and circadian gene expression for worms exposed to ALAN.

Denham, J. et al. (2017) International Worm Meeting "An integrated neuro-mechanical model of C. elegans forward locomotion."

Ranner, T., Denham, J., Cohen, N.

[International Worm Meeting, 2017]

Behavioural responses in C. elegans can be observed through changes in locomotive patterns. It is therefore important to consider the role of the physics in computational models of the neural circuit for motor behaviours. We present a dynamical systems model of C. elegans forward locomotion in which the neural circuit is divided into a series of repeating identical units, coupled via posterior stretch receptor feedback. Each unit includes cholinergic, bistable B-type motor neurons (modelled after bistable RMD neurons, Mellem et al. 2008, Boyle et al. 2012), implicit GABAergic D-type motor neurons (Boyle et al. 2012) and nonlinear viscoelastic muscle forcing along the body (Boyle et. al. 2012). The neural model incorporates proprioceptive feedback as the mechanism for producing sustained oscillations. Integrating the neural model with a recent continuum mechanical body model (Cohen and Ranner 2017) provides this feedback and is also the method for incorporating environmental drag from the surrounding fluid, closing the neuronal-environmental loop. Biophysically realistic parameters are used to obtain sustained travelling waves in muscle activation which respond to changes in environmental viscoelasticity. To explore the pattern generation mechanism, we present results from bifurcation analysis performed in the isolated neural framework and in the fully integrated neuro-mechanical model. We show how these results are modulated by changes in the external drag and internal material properties of the passive and active body. References [1] Boyle JH, Berri S, Cohen N: Gait modulation in c. elegans: an integrated neuro-mechanical model. Frontiers in computational neuroscience 2012, 6:10. [2] Mellem JE, Brockie PJ, Madsen DM, Maricq AV: Action potentials contribute to neuronal signaling in C. elegans, Nature Neuroscience 2008, 11:865-867 [3] Cohen N, Ranner T: A new computational method for a model of C. elegans biomechanics: Insights into elasticity and locomotion performance, arXiv:1702.04988, 20

Bethany Simmons et al. (2001) International C. elegans Meeting "Regulation of unc-13 and Subcellular Localization of its Protein Products"

Alan Cohen, Bethany Simmons, Amy Garber, Rebecca Eustance Kohn, Toni Vitullo, Lynn Schwarting, Megan Guziewicz, Kelly Howell

[International C. elegans Meeting, 2001]

We are examining regulation of synaptic neurotransmission. We are studying the unc-13 gene, which is part of a signal transduction pathway affecting neurotransmitter release. At least one product of this gene is involved in the step between synaptic vesicle docking and fusion. While most studies of UNC-13 have examined the 200 kDa form of the protein, multiple forms of UNC-13 proteins are expressed. At least three types of proteins are made from the gene, and these proteins may have different functions in cells. We are interested in understanding the roles of the different forms of UNC-13 in C. elegans . In particular, we are asking where the protein products localize and how protein expression is regulated. To approach these questions, we are developing antibodies to identify the subcellular localization patterns of the different UNC-13 proteins. Antibodies were made previously to recognize the 200 kDa form of the protein, but these antibodies cannot label all forms of UNC-13. We are interested in determining whether all forms of the proteins are found in neurons and whether they localize in synapses. We are also examining the possibility that an internal promoter is involved in gene regulation. We are constructing GFP fusions to determine whether an internal region of the unc-13 gene is capable of driving transcription of a subset of unc-13 mRNA.

Shownkeen R et al. (1995) International C. elegans Meeting "THE CAENORHABDITIS ELEGANS PHYSICAL MAP"

Chissoe SL, Waterston RH, Fraser A, Sulston JE, Shownkeen R, Coulson AR

[International C. elegans Meeting, 1995]

Twelve contigs of cosmids and yeast artificial chromosomes (YACs) span more than 95Mb of the 100Mb C.elegans genome. 650 markers link the physical and genetic maps.Hybridisation of tag-sequenced cDNA clones to a map-representative set of YACs indicates that the map incorporates in excess of 99.8% of genes. The map is accessible in ACeDB. We (S.C.) are investigating the representation by bacterial artificial chromosomes (BACs) of regions of the genome not represented by cosmids. Two grids of YACs, of 958 clones ('Poly2') and 223 clones ('Suppoly') are available on request. The latter represents regions of the genome that have been characterised or better defined since the selection of clones for the former. Cosmid clones and YAC grids are available from the Sanger Centre (requests to alan@sanger.ac.uk; FAX 01223 494919). YAC clones and 'cm' series cDNA clones are available from the Sanger Centre or Washington University (rw@nematode. wustl.edu; FAX 314 362 2985).

Chan S et al. (1991) International C. elegans Meeting "SEEKING UNC-40."

Culotti JG, Su M-W, Chan S, Hedgecock EM

[International C. elegans Meeting, 1991]

unc-40 is required with unc-6 to guide ventral migrations on the nematode epidermis (Hedgecock et al., Neuron 4, 61-85, 1990). We have positioned unc-40 genetically by 3-factor crosses with dpy-5 and bli-4 as flanking markers and we have isolated 5 new alleles of unc-40 (2 spontaneous, 2 gamma, and 1 EMS) making a total of 12. DNAs from cosmids covering this region (obtained from Alan Coulson and John Sulston) are being used to probe DNA and RNA from the mutants and DNA from strains carrying duplications that break to either side of unc-40 (obtained from Anne Rose's laboratory). We are also injecting cosmid DNAs into gonads to look for rescue by germline transformation. The brood sizes of various unc-40 alleles are very small, so we have resorted to injecting the wild type in order to create a series of transformed lines, each carrying an extrachromosomal array of a different cosmid. Each array will be passed into appropriately marked unc-40 animals to ask if any can rescue the mutant phenotype. Mosaic experiments are also underway to determine whether unc-40 acts in migrating cells.

Stefano Berri et al. (2008) European Worm Meeting "The role of the body in determining C. elegans locomotion waveforms: experiment and theory."

Ian A Hope, Stefano Berri, Netta Cohen, Jordan H Boyle

[European Worm Meeting, 2008]

C. elegans locomotion is typically studied on agar, where forward crawling. is well described by a characteristic waveform. Models of the neural and. neuromuscular control of locomotion have been restricted to modeling such. crawling behavior. Specifically, Niebur and Erdos (1991) suggest that the. sinusoidal track, or groove, left by a worm on an agar surface is. functionally significant.. The importance of the groove in determining the shape of the body may. resolve an important difference between the two existing classes of models. of forward locomotion. In the model of Niebur and Erdos (1991), the worm. relies on a central pattern generator (CPG) in the head to determine the. frequency of undulations and effectively create a groove for the rest of. the body to follow through. The body shape is therefore determined by the. path of the head. In contrast, the Bryden and Cohen model (2004, 2008) does. not include the constraints of a groove, and so the shape of the body is. determined by the muscle activation pattern all along the worm. To. determine to what extent the entire body is used by the worm to determine. its waveform during crawling behavior, we set out to investigate whether. the worm can determine its own waveform in the absence of a groove.. We compared the locomotion on agar with that of worms on a smooth, solid. (nitrocellulose) surface, which precludes the possible formation of a. groove.. Results indicate the following:. (i) The worm is capable of generating and propagating a waveform very. similar to that of forward crawling on agar.. (ii) Nonetheless, no forward motion results on the solid surface.. (iii) Using locomotion data analysis, we are able to estimate the. properties of the groove on agar and to confirm the absence of similar. forces on a solid surface.. (iv) Using a model adapted from Niebur and Erdos (1991) (Boyle, Bryden and. Cohen 2007), we successfully replicate the results in an environment. mimicking a groove. However, for insufficiently strong grooves (in. particular matching the strength of the groove to our observations of. behavior on agar) the mechanism breaks down, as the muscle activation. pattern alone is not sufficient to fully determine the body shape.. (v) Simulations of model worms with imposed waveforms and undulation. frequencies on a solid surface successfully explain the observed. experimental results.. Our work suggests that the crawling waveform of the worm does not require a. groove, and therefore that the body shape cannot be purely determined by. the motion of the head and the properties of the environment. In. particular, a minimal muscle activation pattern that generates thrust. within a groove is not sufficient to explain the behavior of the worm on a. solid surface. The worm must recruit muscles along the body to determine. the shape of the body in time.. Our conclusions may have important implications for further modeling of. neural control of locomotion in general and for predictions about the. distribution of postulated stretch receptors along ventral cord. motoneurons, in particular.

Beitel GJ et al. (1991) International C. elegans Meeting "CLONING AND SEQUENCING OF THE SYNTHETIC MULTIVULVAL GENE lin-9"

Beitel GJ, Horvitz HR

[International C. elegans Meeting, 1991]

A synthetic Multivulva phenotype can result from mutations in two separate genes, while each mutation alone results in an apparently wild-type phenotype (Ferguson and Horvitz, Genetics 123:109-121,1989). Mutations that can cause this synthetic Multivulva (syn Muv) phenotype have been grouped into two classes, A and B, such that a double mutant carrying one mutation in each class will have the syn Muv phenotype. Iin-9(nll2) III is a class B mutation that results in an apparently wild-type phenotype by itself. We previously reported that ZK637 and overlapping cosmids can rescue lin-9 (WBG 11(2 ): p 29,1990). We have now identified an 8 kb subclone with rescuing activity. Using this 8 kb fragment to probe Stuart Kim's cDNA library, six positive plaques representing at least three independent clones were isolated. This 8 kb probe also detects a message of approximately 2.5 kb on Northern blots. The message level appears similar in eggs and mixed-stage populations. We are currently sequencing these cDNAs and looking for evidence that these transcripts do in fact represent the lin-9 gene. This work will be greatly aided by the genomic sequence provided by Molly Craxton, John Sulston and Alan Coulson, as ZK637 was fortuitously chosen as one of the first cosmids to be sequenced in the worm genome sequencing project.

James P McCarter et al. (2001) International C. elegans Meeting "Genes from Other"

Michael Dante, James P McCarter, John C Martin, Deana Pape, Brandi Chiapelli, Todd N Wylie, Robert H Waterston, Sandra W Clifton

[International C. elegans Meeting, 2001]

To build upon knowledge gained from the genome of C. elegans , we have begun generating Expressed Sequence Tags (ESTs) from parasitic (and free-living) nematodes. This project will generate >225,000 5' ESTs from 14 species by 2003. Additionally, the Sanger Centre and Edinburgh Univ. will complete 80,000 ESTs from 7 species. Through these combined efforts, we anticipate the identification of >80,000 new nematode genes. At the GSC, approximately 35,000 ESTs have been generated to date including sequences from Ancylostoma caninum, Heterodera glycines, Meloidogyne incognita and javanica, Parastrongyloides trichosuri, Pristionchus pacificus, Strongyloides stercoralis and ratti, Trichinella spiralis, and Zeldia punctata . We will report on our progress in sequence analysis, including the creation of the NemaGene gene index for each species by EST clustering and consensus sequence generation, identification of common and rare transcripts, and identification of genes with orthologues in C. elegans and other nematodes. All sequences are publicly available at www.ncbi.nlm.nih.gov/dbEST. NemaGene sequences and project details are available at WWW.NEMATODE.NET. We would like to thank collaborators who have provided materials and ideas for this project including Prema Arasu, David Bird, Rick Davis, Warwick Grant, John Hawdon, Doug Jasmer, Andrew Kloek, Thomas Nutman, Charlie Opperman, Alan Scott, Ralf Sommer, and Mark Viney. This work is funded by NIH-AI-46593, NSF-0077503, and a Merck / Helen Hay Whitney Foundation fellowship.

Pettitt J et al. (1991) International C. elegans Meeting "A PUTATIVE CYSTEINE RICH PROTEIN IN A. SUUM IS ALMOST A COLLAGEN."

Kingston IB, Pettitt J

[International C. elegans Meeting, 1991]

During the course of our studies of the collagen gene family in Ascaris suum, we isolated one bacteriophage clone from an A. suum genomic library which hybrldized to a C. elegans collagen gene probe but did not contain any collagen (Gly-X-Y) coding regions. Instead, this clone contained an open reading frame which encoded many repeats of the amino acid sequence Gly-Pro-Cys-cys. The expression of this putative gene was examlned by Northern blot analysis. No transcripts were detected in any adult tissue but the gene appeared to be highly expressed in a mixed population of L3 and L4 stage larvae. A search of several protein databases identified only one similar protein; a putative Drosophila sperm protein. With a view to conducting genetic analysis of the protein, we searched for a homologue of the A. suum protein in C. elegans. Using an oligonucleotide which would encode part of the Gly-Pro-Cys-Cys repeats sequence, and taking into account the published C. elegans codon preferences, we probed Alan Coulson's YAC filters and obtained signals from three overlapping YAC clones, which mapped to linkage group IV. We then narrowed the region of hybridisation down to two cosmids, EOlF10 and F41Cl, and we are now sub-cloning and sequencing this region to determine if it does contain the homologue of the A. suum gene.

Baran, Renee A. et al. (2009) International Worm Meeting "zyg-8 Function in C. elegans Motor Neuron Development."

Baran, Renee A., Shirazi, Farah, Tang, Garland

[International Worm Meeting, 2009]

Mutations in alpha-tubulin, doublecortin, and LIS1 block neuron migration and cause lissencephaly in humans. Doublecortin/DCX and doublecortin-like proteins bind microtubules and function to promote microtubule assembly and stability while LIS1 mediates interactions with the dynein motor complex. Doublecortin proteins have also been shown to localize to neurite endings and influence axon outgrowth and dendrite arborization (Friocourt et al., 2003; Deuel et al., 2006; Cohen et al., 2008). zyg-8, the sole C. elegans member of the doublecortin family, encodes a doublecortin-like protein required for positioning the mitotic spindle during embryonic divisions (Gonzcy et al., 2001). We utilized conditional zyg-8 mutants to study the role of zyg-8 in later stages of neuronal development. zyg-8(b235ts) mutants were shifted to the nonpermissive temperature as late embryos or early L1 larvae prior to synapse formation, and the GABAergic motor neurons of mutant adults were analysed for expression of the synaptic vesicle marker SNB-1::GFP, active zone marker UNC-10::RFP, and an axon-restricted microtubule plus-end binding protein. zyg-8 mutants exhibited defects in synapse morphology similar to gain-of-function tba-1 mutants (R. Baran & Y. Jin). SNB-1::GFP puncta were irregular in size and spacing and GFP was mislocalized in the commissures. Synapses were sometimes missing from the most distal regions of axons along the dorsal nerve cord, a phenotype also observed in tba-1(ju89) mutants. These results suggest that zyg-8 may play a significant role in larval and adult motor neurons in maintaining axon and synapse integrity.