scholarly journals UNC-108/RAB-2 and its effector RIC-19 are involved in dense core vesicle maturation in Caenorhabditis elegans

2009 ◽  
Vol 186 (6) ◽  
pp. 897-914 ◽  
Author(s):  
Marija Sumakovic ◽  
Jan Hegermann ◽  
Ling Luo ◽  
Steven J. Husson ◽  
Katrin Schwarze ◽  
...  
Keyword(s):  
Nervous System ◽  
Caenorhabditis Elegans ◽  
Vesicular Trafficking ◽  
Dense Core ◽  
Dense Core Vesicle ◽  
Vesicle Release ◽  
C Elegans ◽  
Golgi Membranes ◽  
Human Diabetes ◽  
Synaptic Vesicle Release

Small guanosine triphosphatases of the Rab family regulate intracellular vesicular trafficking. Rab2 is highly expressed in the nervous system, yet its function in neurons is unknown. In Caenorhabditis elegans, unc-108/rab-2 mutants have been isolated based on their locomotory defects. We show that the locomotion defects of rab-2 mutants are not caused by defects in synaptic vesicle release but by defects in dense core vesicle (DCV) signaling. DCVs in rab-2 mutants are often enlarged and heterogeneous in size; however, their number and distribution are not affected. This implicates Rab2 in the biogenesis of DCVs at the Golgi complex. We demonstrate that Rab2 is required to prevent DCV cargo from inappropriately entering late endosomal compartments during DCV maturation. Finally, we show that RIC-19, the C. elegans orthologue of the human diabetes autoantigen ICA69, is also involved in DCV maturation and is recruited to Golgi membranes by activated RAB-2. Thus, we propose that RAB-2 and its effector RIC-19 are required for neuronal DCV maturation.

Behavioral Effects of Volatile Anesthetics in Caenorhabditis elegans

1996 ◽  
Vol 85 (4) ◽  
pp. 901-912 ◽  
Author(s):  
Michael C. Crowder ◽  
Laynie D. Shebester ◽  
Tim Schedl
Keyword(s):  
Nervous System ◽  
Caenorhabditis Elegans ◽  
Time Course ◽  
Model Organism ◽  
Volatile Anesthetic ◽  
Volatile Anesthetics ◽  
Effective Concentration ◽  
Forward Genetics ◽  
C Elegans ◽  
Median Effective Concentration

Background The nematode Caenorhabditis elegans offers many advantages as a model organism for studying volatile anesthetic actions. It has a simple, well-understood nervous system; it allows the researcher to do forward genetics; and its genome will soon be completely sequenced. C. elegans is immobilized by volatile anesthetics only at high concentrations and with an unusually slow time course. Here other behavioral dysfunctions are considered as anesthetic endpoints in C. elegans. Methods The potency of halothane for disrupting eight different behaviors was determined by logistic regression of concentration and response data. Other volatile anesthetics were also tested for some behaviors. Established protocols were used for behavioral endpoints that, except for pharyngeal pumping, were set as complete disruption of the behavior. Time courses were measured for rapid behaviors. Recovery from exposure to 1 or 4 vol% halothane was determined for mating, chemotaxis, and gross movement. All experiments were performed at 20 to 22 degrees C. Results The median effective concentration values for halothane inhibition of mating (0.30 vol%-0.21 mM), chemotaxis (0.34 vol%-0.24 mM), and coordinated movement (0.32 vol% - 0.23 mM) were similar to the human minimum alveolar concentration (MAC; 0.21 mM). In contrast, halothane produced immobility with a median effective concentration of 3.65 vol% (2.6 mM). Other behaviors had intermediate sensitivities. Halothane's effects reached steady-state in 10 min for all behaviors tested except immobility, which required 2 h. Recovery was complete after exposure to 1 vol% halothane but was significantly reduced after exposure to immobilizing concentrations. Conclusions Volatile anesthetics selectively disrupt C. elegans behavior. The potency, time course, and recovery characteristics of halothane's effects on three behaviors are similar to its anesthetic properties in vertebrates. The affected nervous system molecules may express structural motifs similar to those on vertebrate anesthetic targets.

scholarly journals The Phosphoprotein Synapsin Ia Regulates the Kinetics of Dense-Core Vesicle Release

2021 ◽  
Vol 41 (13) ◽  
pp. 2828-2841
Author(s):  
Hui-Ju Yang ◽  
Pin-Chun Chen ◽  
Chien-Ting Huang ◽  
Tzu-Lin Cheng ◽  
Sheng-Ping Hsu ◽  
...  
Keyword(s):  
Dense Core ◽  
Dense Core Vesicle ◽  
Vesicle Release ◽  
Kinetics Of

scholarly journals Functional connectomics from neural dynamics: probabilistic graphical models for neuronal network of Caenorhabditis elegans

2018 ◽  
Vol 373 (1758) ◽  
pp. 20170377 ◽  
Author(s):  
Hexuan Liu ◽  
Jimin Kim ◽  
Eli Shlizerman
Keyword(s):  
Time Series ◽  
Nervous System ◽  
Caenorhabditis Elegans ◽  
Graphical Models ◽  
Neuronal Network ◽  
Graphical Model ◽  
Time Series Data ◽  
Series Data ◽  
Neuronal Responses ◽  
C Elegans

We propose an approach to represent neuronal network dynamics as a probabilistic graphical model (PGM). To construct the PGM, we collect time series of neuronal responses produced by the neuronal network and use singular value decomposition to obtain a low-dimensional projection of the time-series data. We then extract dominant patterns from the projections to get pairwise dependency information and create a graphical model for the full network. The outcome model is a functional connectome that captures how stimuli propagate through the network and thus represents causal dependencies between neurons and stimuli. We apply our methodology to a model of the Caenorhabditis elegans somatic nervous system to validate and show an example of our approach. The structure and dynamics of the C. elegans nervous system are well studied and a model that generates neuronal responses is available. The resulting PGM enables us to obtain and verify underlying neuronal pathways for known behavioural scenarios and detect possible pathways for novel scenarios. This article is part of a discussion meeting issue ‘Connectome to behaviour: modelling C. elegans at cellular resolution’.

scholarly journals Dense Core Vesicle Dynamics in Caenorhabditis elegans Neurons and the Role of Kinesin UNC-104

Traffic ◽  
2004 ◽  
Vol 5 (7) ◽  
pp. 544-559 ◽  
Author(s):  
Tobias R. Zahn ◽  
Joseph K. Angleson ◽  
Margaret A. MacMorris ◽  
Erin Domke ◽  
John F. Hutton ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Dense Core ◽  
Dense Core Vesicle ◽  
Vesicle Dynamics

Genetics of Behavior in C. elegans

2017 ◽  
pp. 150-170 ◽  
Author(s):  
Denise S. Walker ◽  
Yee Lian Chew ◽  
William R. Schafer
Keyword(s):  
Nervous System ◽  
Caenorhabditis Elegans ◽  
Molecular Genetics ◽  
Sensory Information ◽  
Macro Level ◽  
Gene Products ◽  
Individual Gene ◽  
C Elegans ◽  
Behavioral States ◽  
Motor Outputs

The nematode Caenorhabditis elegans is among the most intensely studied animals in modern experimental biology. In particular, because of its amenability to classical and molecular genetics, its simple and compact nervous system, and its transparency to optogenetic recording and manipulation, C. elegans has been widely used to investigate how individual gene products act in the context of neuronal circuits to generate behavior. C. elegans is the first and at present the only animal whose neuronal connectome has been characterized at the level of individual neurons and synapses, and the wiring of this connectome shows surprising parallels with the micro- and macro-level structures of larger brains. This chapter reviews our current molecular- and circuit-level understanding of behavior in C. elegans. In particular, we discuss mechanisms underlying the processing of sensory information, the generation of specific motor outputs, and the control of behavioral states.

scholarly journals A lineage-resolved molecular atlas of C. elegans embryogenesis at single-cell resolution

Science ◽  
2019 ◽  
Vol 365 (6459) ◽  
pp. eaax1971 ◽  
Author(s):  
Jonathan S. Packer ◽  
Qin Zhu ◽  
Chau Huynh ◽  
Priya Sivaramakrishnan ◽  
Elicia Preston ◽  
...  
Keyword(s):  
Nervous System ◽  
Caenorhabditis Elegans ◽  
Single Cell ◽  
Molecular Basis ◽  
Cell Types ◽  
Embryonic Cells ◽  
Cell Type ◽  
C Elegans ◽  
Exact Position ◽  
Sister Cells

Caenorhabditis elegans is an animal with few cells but a wide diversity of cell types. In this study, we characterize the molecular basis for their specification by profiling the transcriptomes of 86,024 single embryonic cells. We identify 502 terminal and preterminal cell types, mapping most single-cell transcriptomes to their exact position in C. elegans’ invariant lineage. Using these annotations, we find that (i) the correlation between a cell’s lineage and its transcriptome increases from middle to late gastrulation, then falls substantially as cells in the nervous system and pharynx adopt their terminal fates; (ii) multilineage priming contributes to the differentiation of sister cells at dozens of lineage branches; and (iii) most distinct lineages that produce the same anatomical cell type converge to a homogenous transcriptomic state.

scholarly journals PKA/KIN-1 mediates innate immune responses to bacterial pathogens in Caenorhabditis elegans

2017 ◽  
Vol 23 (8) ◽  
pp. 656-666 ◽  
Author(s):  
Yi Xiao ◽  
Fang Liu ◽  
Pei-ji Zhao ◽  
Cheng-Gang Zou ◽  
Ke-Qin Zhang
Keyword(s):  
Innate Immunity ◽  
Nervous System ◽  
Caenorhabditis Elegans ◽  
Immune Responses ◽  
Innate Immune ◽  
Autophagic Flux ◽  
Innate Immune Responses ◽  
C Elegans ◽  
Downstream Effector ◽  
Model Animal

The genetically tractable organism Caenorhabditis elegans is a powerful model animal for the study of host innate immunity. Although the intestine and the epidermis of C. elegans that is in contact with pathogens are likely to function as sites for the immune function, recent studies indicate that the nervous system could control innate immunity in C. elegans. In this report, we demonstrated that protein kinase A (PKA)/KIN-1 in the neurons contributes to resistance against Salmonella enterica infection in C. elegans. Microarray analysis revealed that PKA/KIN-1 regulates the expression of a set of antimicrobial effectors in the non-neuron tissues, which are required for innate immune responses to S. enterica. Furthermore, PKA/KIN-1 regulated the expression of lysosomal genes during S. enterica infection. Our results suggest that the lysosomal signaling molecules are involved in autophagy by controlling autophagic flux, rather than formation of autophagosomes. As autophagy is crucial for host defense against S. enterica infection in a metazoan, the lysosomal pathway also acts as a downstream effector of the PKA/KIN-1 signaling for innate immunity. Our data indicate that the PKA pathway contributes to innate immunity in C. elegans by signaling from the nervous system to periphery tissues to protect the host against pathogens.

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