Chen X et al. (2015) Mol Neurodegener "Erratum to: Ethosuximide ameliorates neurodegenerative disease phenotypes by modulating DAF-16/FOXO target gene expression."

McCue HV, Chen X, Morgan A, Kashyap SS, Barclay JW, Kraemer BC, Burgoyne RD, Wong SQ

[Mol Neurodegener, 2015]

The original version of this article [1] unfortunately contained a mistake. The author list contained a spelling error for the author Hannah V. McCue. The original article has been corrected for this error. The corrected author list is given below:Xi Chen, Hannah V. McCue, Shi Quan Wong, Sudhanva S. Kashyap, Brian C. Kraemer, Jeff W. Barclay, Robert D. Burgoyne and Alan Morgan

Ceol CJ et al. (1997) International C. elegans Meeting "CLONING AND CHARACTERIZATION OF THE SYNTHETIC MULTIVULVA CLASS B GENES lin-52 AND lin-55"

Ceol CJ, Horvitz HR

[International C. elegans Meeting, 1997]

The synthetic multivulva (synMuv) genes negatively regulate a receptor tyrosine kinase/Ras pathway that controls vulval induction. The synMuv genes are grouped into two classes, A and B. Animals mutant in a single class are wild-type with respect to vulval development, whereas animals mutant in both an A class and a B class gene are Muv. Classes A and B are proposed to define functionally redundant pathways that inhibit vulval induction (Ferguson and Horvitz, 1989, Genetics 123: 109-121). To investigate these pathways at a molecular level, we are cloning the class B genes lin-52 and lin-55. lin-52 maps between unc-69 and unc-16 on LGIII (Jeff Thomas, personal communication). We have injected cosmid pools from this region and have obtained rescue. We are currently subcloning one of these cosmids to generate a minimal rescuing fragment. lin-55 maps between unc-4 and rol-6 on LGII (Jeff Thomas, personal communication). We are attempting transformation rescue with cosmids from this region. Both lin-52 and lin-55 are defined by a single alleles, and, in each case, deficiency studies indicate the existing alleles are not null. For this reason, we intend to conduct non-complementation screens to obtain more severe loss-of-function alleles. We also intend to search for potential interactions among the synMuv proteins using the yeast two-hybrid system.

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.

Segade F et al. (2006) Arch Otolaryngol Head Neck Surg "Association of the FBXO11 gene with chronic otitis media with effusion and recurrent otitis media: the Minnesota COME/ROM Family Study."

Brown SD, Segade F, Brown M, Daly KA, Hicks PJ, Rich SS, Cox M, Bowden DW, Allred D, Hardisty-Hughes RE

[Arch Otolaryngol Head Neck Surg, 2006]

OBJECTIVE: The FBXO11 gene is the human homologue of the gene mutated in the novel deaf mouse mutant jeff (Jf), a single gene model of otitis media. We have evaluated single nucleotide polymorphisms (SNPs) in the FBXO11 gene for association with chronic otitis media with effusion/recurrent otitis media (COME/ROM). DESIGN: A total of 13 SNPs were genotyped across the 98.7 kilobases of genomic DNA encompassing FBXO11. Data were analyzed for single SNP association using generalized estimating equations, and haplotypes were evaluated using Pedigree Disequilibrium Test methods. PATIENTS: The Minnesota COME/ROM Family Study, a group of 142 families (619 subjects) with multiple affected individuals with COME/ROM. MAIN OUTCOME MEASURES: Genetic association of COME/ROM with polymorphisms in FBXO11. RESULTS: The FBXO11 SNPs are contained in a single linkage disequilibrium haplotype block. Ten of the 13 SNPs were sufficiently polymorphic in the sample to permit analysis. In univariate genetic analysis, 1 reference SNP (hereinafter rs) (rs2134056) showed nominal evidence of association to COME/ROM (P = .02), and 2 SNPs approached significance (rs2020911, P = .06; rs3136367, P = .09). In multivariable analyses, including known risk factors for COME/ROM (sex, exposure to smoking, attending day care centers, no prior breastfeeding, and having allergies), the evidence of independent association was reduced for each SNP (eg, rs2134056, from P = .02 to P = .08). In subsequent analyses using the Pedigree Disequilibrium Test, the association of FBXO11 SNP rs2134056 (P = .06) with COME/ROM was confirmed. Incorporating multiple SNPs in 2- and 3-locus SNP haplotypes, those haplotypes containing rs2134056 also exhibited evidence of association of FBXO11 and COME/ROM (P values ranging from .03 to .10). CONCLUSION: We have observed evidence consistent with an association between polymorphisms in FBXO11, the human homologue of the Jeff mouse model gene, and COME/ROM.

Chen, Sway et al. (2015) International Worm Meeting "Functional and anatomical analysis of the L1 motor circuit."

Schalek, Richard, Laskova, Valeriya, Chen, Sway, Cook, Steven, Suriyalaksh, Manusnan, Lichtman, Jeff, Guan, Asuka, Mitchell, James, Neubauer, Marianna, Witvliet, Daniel, Wen, Quan, Zhen, Mei, Samuel, Aravinthan, Lu, Yangning, Mulcahy, Ben

[International Worm Meeting, 2015]

At all developmental stages, C. elegans navigates its environment by generating and propagating bending waves along its body. The neuronal circuit controlling locomotory behavior, however, changes significantly at the end of the L1 larval stage. During the L1 stage, B- and A-type cholinergic motor neurons innervate dorsal body wall muscles but not ventral muscles. D-type GABAergic motor neurons innervate ventral muscles but not dorsal muscles. Calcium imaging and optogenetic stimulation suggest that D-type neurons are inhibitory at the L1 stage, causing ventral muscles to relax. At the L2 stage and beyond, both ventral and dorsal muscles are symmetrically innervated by cholinergic and GABAergic motor neurons, and phasic excitation coupled to contralateral inhibition is thought to be responsible for the propagation of undulatory waves. So how does the worm produce undulatory behavior at the L1 stage given the profound ventral/dorsal asymmetry in excitatory cholinergic and inhibitory GABAergic inputs? To answer this question, we have reconstructed the L1 motor circuit using serial section electron microscopy. We are now using targeted cellular ablation, calcium imaging, and optogenetics to pinpoint the mechanism for ventral muscle contraction, and understand how alternating waves of excitation and relaxation drive undulation during the L1 stage. Our goal is a detailed mechanistic model of L1 locomotion. Comparing the circuit basis of L1 with adult worm locomotion should shed light on conserved principles of rhythmic locomotion and development of motor circuits.

Mulcahy, Ben et al. (2017) International Worm Meeting "The Dynamics of Synaptic Remodeling: insights from the C. elegans Motor Circuit."

Holmyard, Douglas, Christensen, Ryan, Lichtman, Jeff, Koh, WanXian, Witvliet, Daniel, Schroff, Hari, Mitchell, James, Qu, Yixin, Chisholm, Andrew, Samuel, Aravi, Bermant, Peter, Schalek, Richard, Zhen, Mei, Mulcahy, Ben, Chang, Maggie, Fetter, Rick

[International Worm Meeting, 2017]

During development, neural circuits undergo constant changes: they incorporate new neurons, and maintain, prune or remodel existing synapses. The small and rapidly developing nervous system of C. elegans allows us to address the developmental dynamics of synapses and neurons in the context of an intact neural ensemble. The vast majority of C. elegans postembryonic neurons are motor neurons. Previous studies suggest that at least one group of motor neurons, DD, reverse their neurite polarity entirely: they innervate ventral body wall muscles in the first larval stage, whereas they innervate dorsal muscles in adults. Their role of innervating ventral muscle is taken over by a group of post-embryonically born motor neurons, VD. Precisely how and when such processes occur, without disrupting motility as the motor circuit transitions into the adult form, is poorly described. We used serial section electron microscopy to reconstruct DD and VD motor neurons across development to define the beginning and ending of remodeling. We identified a series of elegantly coordinated synaptogenesis and remodeling events where synaptogenesis events follow different sequential orders for embryonic (DD) and post-embryonic (VD) neurons. Developing VD neurons have some interaction with DD neurons that may help to guide neurite extension and synaptogenesis. These events implicate an elegant mechanism that allows a gradual and seamless transition of the motor circuit to take place without disrupting its functional output.

Berger, Daniel et al. (2015) International Worm Meeting "The mind of an L1 worm - how do neuronal circuits function and remodel throughout development?."

Samuel, Aravinthan, Emmons, Scott, Neubauer, Marianna, Lichtman, Jeff, Witvliet, Daniel, Chisholm, Andrew, Laskova, Valeriya, Mitchell, James, Mulcahy, Ben, Cook, Steven, Zhen, Mei, Schalek, Richard, Berger, Daniel, Hall, David, Holmyard, Douglas, Kersen, David, Qu, Angie

[International Worm Meeting, 2015]

When humans and worms are born, they have neuronal circuits in place to integrate sensory cues and effect appropriate behavioural or homeostatic responses. During the course of development, a substantial amount of remodelling occurs in the nervous system. New neurons are born and integrated into existing circuits, and existing neurons and circuits are remodelled. The rules of this remodelling are poorly characterised, because in order to investigate neuronal circuit development one needs a connectome-level analysis of the circuit across multiple time points, in multiple animals. This strategy requires serial-section electron microscopy, which has been very low-throughput and labour-intensive.C. elegans represents an ideal organism to perform these studies on, because of their small size and stereotypical development - some of the reasons they were chosen for the original adult serial-section EM reconstruction that culminated in the acquisition of the adult connectome, dubbed 'The mind of a worm'. Since the publication of this landmark paper, new technologies have been developed that improve the fidelity and throughput of the connectome reconstruction, including better fixation methods, increased computational power and more advanced microscopes.We are reconstructing the entire nervous system of multiple L1 worms using serial-section transmission and scanning electron microscopy. The L1 worm is of special interest because of the major remodelling that occurs at the end of L1, including the birth of new major classes of motor neurons. We are finding both conserved and unreported structure and connectivity from the published adult wiring diagram. This dataset will be used as a framework to functionally interrogate the interplay between developing circuits and sensorimotor behaviours, and the mechanisms that allow this dialogue to take place.

MF Maduro et al. (1999) International C. elegans Meeting "An RNAi screen for embryonic patterning genes"

MF Maduro, JH Rothman, J Sumerel

[International C. elegans Meeting, 1999]

We are taking advantage of RNAi as a tool for identifying genes with potentially important roles in the developing embryo. This approach circumvents the extensive effort required to molecularly identify the relevant genes identified from mutagenesis or deficiency screening and facilitates identification of genes that might be required both maternally and zygotically. In our screen, we obtain RNA synthesis templates from an extant cDNA library. The templates are pooled in groups of eight and used to synthesize RNA. Although the library we are using has not been normalized, this has not been a major limitation; in preliminary experiments, we found that approximately 35% of pools cause penetrant embryonic arrest. For any phenotype recovered from a pool, we inject or soak individual RNAs and identify the gene from a small amount of cDNA sequence. To expedite analysis of mutant phenotypes, we are using a set of GFP markers, including a translational fusion of the gene encoding the MH27 antigen (a gift from Jeff Simske), which marks the adherens junctions of epithelia and allows us to recover embryos with abnormal epidermal patterning. For example, one pool produced viable L1 animals with a penetrant hypodermal protrusion near the posterior pharyngeal bulb; the MH27::GFP marker revealed a bilateral alteration in the local pattern of hypodermal seam cells. The gene responsible for the phenotype, which has previously been named nmy-1 , encodes a non-muscle myosin; we are currently investigating the role of this gene in seam cell development. We will report our progress with nmy-1 and other genes identified in the screen.

Steven RM et al. (1995) International C. elegans Meeting "AN EXPRESSION PATTERN FOR UNC-73"

Culotti JG, Steven RM

[International C. elegans Meeting, 1995]

Mutations in the gene unc-73 result in a complex set of defects, a subset being defects in axon guidance. Lethal mutations in unc-73 also exist (Gian Garriga, Jeff Way, personal communications). The presence of a "dbl domain" in the gene sequence indicates that the UNC-73 protein may participate in the organization of the actin cytoskeleton (WBG 12:4, p.29). Two versions of an unc-73/lacZ fusion construct were made. One contains 4.2 kb of unc-73 5' upstream sequence and the other contains only 1.2 kb. Both constructs contain the first exon and intron of unc-73 and are fused midway through the second exon of unc-73 in frame to lacZ. The same pattern of expression is seen with both of the constructs. In the adult the expression is restricted to two cell types, a subset of neurons and all of the seam cells. The expression in embryos and the early larval stages is more widespread and includes some hypodermal cells and probably the P cells. Several polyclonal antibodies were raised against three different regions of the UNC-73 protein. Indirect immunofluoresence of N2 worms incubated with any of these antibodies reveals staining in the nerve ring. The nerve ring staining is seen in late embryos through to adults. In late larval stages and in adults the ventral cord also stains. This staining pattern is consistent with the lacZ data if the UNC-73 protein is considered to be of low abundance and can therefore only be seen in the major neuropil of the worm.

Harrison M et al. (2000) East Coast Worm Meeting "Identification and characterization of genes that act with lin-35 Rb to negatively regulate vulval induction"

Horvitz HR, Ceol CJ, Harrison M, Stegmeier F

[East Coast Worm Meeting, 2000]

The synthetic multivulva (synMuv) class A and class B genes define two functionally redundant pathways that antagonize Ras signaling during vulval induction. Molecular analyses of the class B synMuv genes have defined a C. elegans pathway that includes a counterpart of the mammalian retinoblastoma, or Rb, tumor suppressor gene. Members of this pathway include lin-35 Rb, genes encoding the presumed heterodimeric transcription factor DPL-1 DP / EFL-1 E2F, and genes, such as lin-53 RbAp48 and hda-1 HDAC, predicted to modulate chromatin structure. The class B synMuv gene lin-54 was originally identified in screens conducted by Jeff Thomas, a former graduate student in our laboratory. We cloned lin-54 and found that it encodes a novel protein with cysteine-rich motifs. These motifs have cysteine signatures unlike those found in proteins with known functions; however, these motifs are conserved in proteins predicted from mammalian, plant and fly ESTs. A rescuing lin-54::gfp transgene is expressed broadly and is localized to nuclei, an expression pattern like that of all synMuv genes thus far assayed. We obtained two deletion alleles of lin-54 and found that, in addition to a Muv phenotype in a synmuvA background, they cause sterility in a wild-type background. We are currently characterizing this sterile phenotype. We are also identifying new class B genes. Using a lin-15A background, we screened 6,500 mutagenized haploid genomes and obtained 95 Muv mutant strains. A partial analysis of these mutants has identified at least three previously unknown class B synMuv genes. We will describe our further characterization of these mutants.