John Farver et al. (2007) International Worm Meeting "Specific UNC-73/Trio RhoGEF-2 isoforms function upstream of the Gas signaling pathway in neurons to physiologically regulate locomotion."

Tony Pawson, John Farver, Robert M. Steven

[International Worm Meeting, 2007]

unc-73 is a complex gene that functions in multiple tissue types at different stages of C. elegans development. unc-73 is essential for normal fertility, required for pharynx and vulval muscle function and for specific cell migrations and it plays a role in axon guidance and neurotransmission in the nervous system (Steven et al, 1998; Steven et al, 2005). unc-73 encodes at least eight protein isoforms that are differentially expressed. These isoforms are thought to function primarily through the activity of their respective RhoGEF domains, which catalyze the activation of members of either the Rac or Rho GTPase subfamilies. Here we attempt to better define the role of the UNC-73 isoforms in neurotransmission. Isoform specific rescue experiments previously revealed that the UNC-73C1, C2/F and E isoforms act redundantly to regulate the speed of locomotion. Transgenic animals lacking these isoforms have a lethargic movement phenotype that can be rescued by the expression of any individual isoform from this group. By using different cell-specific or inducible promoters to drive the expression of UNC-73E in transgenic unc-73 mutant animals we have started to narrow down the temporal and spatial requirements of UNC-73E function. We have found that UNC-73E acts within the nervous system, although not exclusively in the cholinergic motor neurons, to physiologically regulate locomotion. Epistasis analysis with other genes involved in the regulation of locomotion revealed that activating mutations in different components of the G<font face=symbol>a</font>_s pathway rescue the unc-73 lethargic movement phenotype caused by the loss of the UNC-73C1, C2/F and E isoforms. These data further point to a role for these isoforms in the regulation of synaptic activity. Since the G<font face=symbol>a</font>_s pathway acts primarily within the cholinergic motorneurons (Charlie et al, 2006), distinct from the site of activity of the UNC-73 isoforms, we propose that these isoforms function in neuromodulatory neurons, perhaps regulating neuromodulators or their receptors within these neurons. Along with the RhoGEF domains, unc-73 encodes other protein-protein interaction motifs including spectrin-repeat-like, SH3, Ig and FnIII domains. Using the yeast two-hybrid system we are in the process of screening for proteins that interact with the UNC-73 isoforms. The homologs of two of the proteins that we identified in our first screen are reported to function in vesicle trafficking, which may explain why unc-73 is involved in many cellular processes.

Laskova, Valeriya et al. (2013) International Worm Meeting "Mapping the entire connectome of C. elegans L1 larvae."

Zhen, Mei, Kasthuri, Bobby, Shalek, Richard, Lichtman, Jeff, Samuel, Aravi, Pfister, Hanspeter, Laskova, Valeriya, Kaynig-Fittkau, Verena, Wen, Quan, Berger, Daniel, Guan, Asuka

[International Worm Meeting, 2013]

To investigate the poorly understood mechanisms of development and function of the nervous system, connections between neurons must be deciphered first. The adult nervous system of C. elegans was mapped to near completion by Dr. John White and his colleagues in 1970s. However, neuronal wiring in C. elegans larvae differs from that of an adult, since it undergoes multiple rounds of neuronal birth, apoptosis and rewiring during development. We utilize an Automatic Tape-Collecting Ultramicrotome (ATUM) to section an entire L1 stage animal into thousands cross-sections, followed by the automated imaging with a scanning electron microscope (SEM) to map an entire neuronal wiring diagram with synaptic resolution. The acquired wiring diagram will guide and be validated by calcium imaging to map the functional connection of the juvenile motor circuit.

Phuongnhung Nguyen et al. (2006) Neuronal Development, Synaptic Function, and Behavior Meeting "Dissecting Genetically the Neural Networks that Coordinate Locomotion"

Bill Walthall, Gennady Cymbalyuk, Phuongnhung Nguyen

[Neuronal Development, Synaptic Function, and Behavior Meeting, 2006]

The networks of nerves and muscles responsible for forward and backward movements in C. elegans offer unique advantages for investigating the functional relationships among cells in integrated cellular networks. The first advantage is that John Sulston and his colleagues identified the interneurons, motor neurons and muscle cells that compose the networks (Sulston, et al., 1983). Second, John White and colleagues determined the synaptic patterns that interconnect the network (White et al., 1986). Finally, the C. elegans community has generated mutations that cause specific alterations in the cellular networks. A model based on the connectivity pattern and laser ablation results suggests that distinct sets of interneurons and excitatory motor neurons are dedicated to forward and backward movement, respectively. These two circuits converge upon two classes of inhibitory motor neurons and four longitudinal strands of body wall muscles and create antiphasic contractile muscular waves that travel along the dorsal and ventral axes of the body. We will report results from the analysis of movies showing locomotion patterns of animals. These movies allows us to quantitatively characterize the traveling wave in terms of amplitudes, dorsal and ventral deflections, frequency and velocity of the wave progression and the forward and backward velocity of the animal's progression. We will compare wild-type locomotion characteristics with those exhibited by three uncoordinated mutants (unc-4, unc-55, and cnd-1) that are known to make specific alterations in the network that result in movement defects that are predicted by the model. The connectivity model can also be used to predict epistatic relationships for double mutant combinations (for example unc-55 mutants exhibit a ventral asymmetric pattern of backward movement, whereas unc-4 exhibits a dorsal asymmetric pattern of backward movement). We find that unc-4 masks the defect of unc-55 mutants, which is predicted by the model neural circuit. However the model's predictions for forward movement are not as accurate. We will discuss possible explanations for the resiliency of forward movement and the vulnerability of backward movement to genetic perturbations.

Consortium Wormbase et al. (2000) West Coast Worm Meeting "From ACeDB to a more complete and usable database"

Consortium Wormbase, Foltz NL, Schwarz EM, Sternberg PW

[West Coast Worm Meeting, 2000]

We briefly describe the current status and plans for WormBase, initially an extension of the existing ACeDB database with a new user interface. The WormBase consortium includes the team that developed ACeDB (Richard Durbin and colleagues at the Sanger Centre; Jean Thierry-Mieg and colleagues at Montpellier); Lincoln Stein and colleagues at Cold Spring Harbor, who developed the current web interface for WormBase; and John Spieth and colleagues at the Genome Sequencing Center at Washington University, who along with the Sanger Centre team, continue to annotate the genomic sequence. The Caltech group will curate new data including cell function in development, behavior and physiology, gene expression at a cellular level, and gene interactions. Data will be extracted from the literature, as well as by community submission. We look forward to providing the C. elegans and broader research community easy access to vast quantities of high quality data on C. elegans. Also, we welcome your suggestions and criticism at any time. WormBase can be accessed at www.wormbase.org.

Ken-ichi Oshio et al. (2002) Japanese Worm Meeting "Revision of synaptic connectivity database"

Eizo Akiyama, Yuishi Iwasaki, Yuko Osana, Ken-ichi Oshio, Sohei Gomi, Satoru Morita, Kotaro Oka, Kazumi Omata

[Japanese Worm Meeting, 2002]

The synaptic connectivity of C. elegans is well known from observations of the somatic system by White et al. and those of the pharyngeal system by Albertson et al. So far, three databases were constructed for computational usage by Achacoso et al. and Durbin, and recently in WormBase. However, they lack some data such as those in tables of White's paper and those in figures of Albertson's book. Our database (K. Oshio, S. Morita, Y. Osana and K. Oka: Technical Report of CCEP, Keio Future No.1, 1998) includes all data described in White's paper and Albertson's book. Unfortunately, some mistakes were found in the database through private communications with John White who is the author of White's paper and with the users of the database. Thus we have been proceeding with the revision to make it perfect one. We are planning to complete the revision in September 2002. The database should be worthwhile not only for neurophysiological studies, but also for post-genomic interests mediating genomes and behavior.

Kevin Eliceiri et al. (2006) Neuronal Development, Synaptic Function, and Behavior Meeting "A Swept-Field Confocal for Cell Biology Studies"

Kevin Eliceiri, Mike Szulczewski

[Neuronal Development, Synaptic Function, and Behavior Meeting, 2006]

We describe a novel instrument, The Swept-Field Confocal Microscope (SFC) that combines high resolution pinhole imaging with slit imaging. Unlike spinning disk confocal systems that have their pinhole apertures embedded in a spinning disc, the SFC's 32 pinhole array remains stationary. Galvonometric and piezo controlled mirrors sweep the image of the pinholes across the sample. The emission photons are de-scanned and focused through a complementary set of pinholes onto a CCD camera. This results in a high resolution image that can be collected at up to 100 frames/second in the pinhole mode and greater than 1000 frames per second in the slit mode. The ability for the scientist to match the optical recording with the temporal biological fluorescence response has great promise for cell and developmental biology studies where live dynamic events must be captured quickly in high resolution. In this poster we describe the optical path of the microscope and present some early data in collaboration with John White's group at the UW-Madison of using the SFC to image GFP constructs in C .elegans to investigate cell division in the early embryo.

Tylon Stephney et al. (2007) International Worm Meeting "WormImage: An online photo album for C. elegans electron microscopy."

Huawei Weng, Maurice Volaski, David H. Hall, Toni Long, Kevin Fisher, Meng Xu, Tylon Stephney

[International Worm Meeting, 2007]

The Hall lab is the home for the physical EM data for C. elegans that was collected by many scientists working at several key laboratories over the past 40 years. We have almost all of the annotated prints, negatives, data notebooks and often the original thin sections and blocks from the MRC, Missouri, Caltech and AECOM collections, including the work of John White, John Sulston, Sam Ward, and many others. This archive includes wild type and mutant data, and covers both males and hermaphrodites, and all ages from embryo to adulthood, and some aging animals. We are scanning much of this physical print data to produce a digital archive of C. elegans anatomy. We have generated about 3 terabytes of digital images, and there is much more scanning to be done. We have designed a simple online photo album, WormImage, to share some of this archive as small thumbnail versions that can quickly transit across the Internet to all users, for free. Bandwidth issues limit our ability to ship full size scans electronically, but we also supply users with higher resolution scans upon request, by ftp or on DVDs. WormImage (www.wormimage.org) is an online database developed for remote retrieval of this digitized microscopy data. Currently this database contains about 20,000 different digital images. Most scans have been taken from the workprints, to preserve original hand annotations which mark identified cell types. The WormImage database is updated weekly to provide more images. The user can search this database by animal name, age, sex, or by regional information (head, midbody, tail) or by tissue types to identify potential images of interest. The user can quickly survey many animals in small thumbnail images, or concentrate on details of a few images expanded to larger size. The program was recently revised to make it easy for the user to click through all the thumbnails for one animal in serial order. Hall has been reviewing the original annotations and writing brief summaries for each animal, also offered on the website. These Color Code summaries help to translate the shorthand markings on the original prints into the familiar cell names for many structures. During 2007, WormImage will begin showing images of key mutant phenotypes and aging animals. We are grateful to Demian Nave and Art Wetzel at the Pittsburgh Supercomputing Center for their help in providing a mirror site. This work is funded by NIH RR 12596.

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.

Jane Shingles et al. (2006) European Worm Meeting "Progress of the Localization of Expression Mapping Project"

Jane Shingles, Denis Dupuy, Marc Vidal, Ian Hope, John Reece-Hoyes

[European Worm Meeting, 2006]

Jane Shingles1, John Reece-Hoyes1, Denis Dupuy2, Marc Vidal2 and Ian Hope1. The Promoterome library containing 6500 Caenorhabditis elegans promoter fragments has previously been generated and used to construct promoter ::GFP fusions to allow determination of gene expression patterns in C. elegans. Optimization of the C. elegans micro-particle bombardment transformation technique, to give a medium through-put system, allowed the generation of expression patterns for over 300 C. elegans promoter::GFP fusions. Promoter fusion constructs of transcription factors genes and genes with homology to human genes with no assigned function were selected for the initial analysis and the results are shown. Initial analysis of the results highlights several significant differences between the two sets of genes. Promoters from C. elegans homologues of human genes with no known function were far more likely to yield either no GFP expression (35% vs. 6%) or ubiquitous GFP expression (23% vs. 8%) under the standard laboratory conditions utilized. In contrast, promoters from C. elegans transcription factor genes were far more likely to drive neuronal expression (62% vs.16%).. Full results are presented on the Hope Laboratory Expression Pattern database URL:http://bgypc059.leeds.ac.uk /~web

Jessica Rivera et al. (2002) West Coast Worm Meeting "Visualizing synapses in the motor neuron circuit."

Sam Wells, Christina Gleason, David M Miller III, Jessica Rivera

[West Coast Worm Meeting, 2002]

A major emphasis of this laboratory is to unravel the mechanism whereby the UNC-4 homeoprotein regulates synaptic specificity in the motor neuron circuit. In unc-4(e120) mutants, the usual inputs to VA motor neurons from AVD, AVD, and AVE command interneurons are replaced with gap junctions from AVB, which are normally reserved for VB motor neurons. The unc-4 wiring defect was initially detected by John White and colleagues by EM reconstruction of serial sections. We are now developing an alternative approach to detect motor neuron-specific synapses in living animals in the confocal microscope. The idea is to label presynaptic and postsynaptic proteins with different colored GFPs and then to use specific promoters to drive expression of these GFP-tagged markers in the command interneurons and in their postsynaptic motor neuron partners. The Zeiss LSM 510 confocal microscope provides argon laser lines that are ideal for discrete excitation of CFP (458 nm) and YFP (514 nm). An authentic synapse in the C. elegans motor neuron circuit labeled in this manner should appear as superimposed CFP and YFP "spots" in the ventral nerve cord.