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http://hdl.handle.net/20.500.11750/308
2024-03-29T04:48:26ZThe nutrient-responsivie insulin signlaing modulates chemosensory responses in C. elegans
http://hdl.handle.net/20.500.11750/47293
Title: The nutrient-responsivie insulin signlaing modulates chemosensory responses in C. elegans
Author(s): Ryu, Lee sun; Kim, Kyuhyung2017-01-16T15:00:00ZGene regulatory networks uderlying cell fate specification of a C. elegans sensory/inter/motor neuron-type
http://hdl.handle.net/20.500.11750/47292
Title: Gene regulatory networks uderlying cell fate specification of a C. elegans sensory/inter/motor neuron-type
Author(s): Heo, Woo Jung; Kim, Kyuhyung
Abstract: Neuronal specification and differentiation are orchestrated through external and internal molecules including transcription factors. However, the mechanisms of how specific transcription factors determine or specify neuronal cell fate during development are not fully understood. In C. elegans, the IL1 sensory/inter/motor neurons consist of six neurons that regulate the rate and pattern of spontaneous foraging movement (Kaplan et al., 1997). To identify molecular and cellular mechanisms by which the IL1 neurons are terminally differentiated, we searched for cis-and trans-acting factors that are necessary and sufficient for specification of the IL1 neurons. First, we performed promoter analysis of the set of genes that are specifically expressed in IL1s, including flp-3neuropeptide gene (Kim et al., 2004). We found several cis-regulatory regions of which deletion caused decreased flp-3expression in the IL1 neurons. More specifically, we identified a motif (referred to as the IL1L/R motif) that is necessary for flp-3expression specifically in the IL1L/R neurons. We are currently testing whether this motif exists in promoters of other IL1-expressed genes and this motif is also sufficient for the expression in IL1L/R. In addition, we performed candidate gene searches and mutagenesis screens to identify trans-acting factor of IL1s, and found that several genes including ceh-43or unc-86regulate flp-3expression in the IL1 neurons. We also isolated several mutant animals which show decreased flp-3expression in the IL1 neurons. We are currently identifying molecular lesions in these mutants.2017-01-16T15:00:00ZCREB influences a developmental desicion in Caenorhabditis elegans
http://hdl.handle.net/20.500.11750/47291
Title: CREB influences a developmental desicion in Caenorhabditis elegans
Author(s): Park, Ji Soo; Kim, Kyuhyung2017-01-16T15:00:00ZStretch sensitive neurons generate rhythmic motor patterns during forward movemnt in C. elegans
http://hdl.handle.net/20.500.11750/47290
Title: Stretch sensitive neurons generate rhythmic motor patterns during forward movemnt in C. elegans
Author(s): Kim, Jinmahn; Kim, Kyuhyung
Abstract: Coordinated voluntary and involuntary movements produce rhythmic motor activities to drive locomotory behaviors of animals. In C. elegans, forward locomotion, which is initiated by contraction and relaxation of head muscles, exhibits the rhythmic motor pattern. However, the neuronal and molecular mechanisms to generate rhythmic motor pattern are not fully understood. Previously, it was shown that ablation of the SMB or SMD neurons caused increased reversal and in addition, SMB ablation increased wave width of sinusoidal movement (Gray et al., 2005). To confirm whether the SMB or SMD neurons function in forward movement, we genetically ablated the SMB or SMD neurons. Either SMB or SMD ablated worms exhibited increased reversal rate compared to wild-type animals. We next found that SMB or SMD exhibited rhythmic calcium transients that were induced by the head bending. To gain further insight into which molecules generate rhythmic calcium transient in SMB, we examined SMB neuronal calcium transients in synaptic transmission mutants including unc-13 (neurotransmitter release regulator), unc-31 (dense-core vesicle fusion activator), or unc-9 (innexin). All three mutants showed normal calcium dynamic in SMB, indicating that the rhythmic calcium influx of SMB is independent of synaptic transmission, and SMB may act as a stretch sensitive/proprioceptive receptor neuron to sense head muscle contraction. To identify the stretch receptor(s) in SMB, we examined expression pattern of 29 TRP and DEG/ENaC channels and found that few genes including unc-8 (DEG/ENaC channel) were expressed in SMB. UNC-8 protein is localized to cell bodies and processes around nerve ring. We also observed that SMB specific unc-8 RNAi causes increased wave width. We are currently analyzing unc-8 mutant phenotypes.2017-01-16T15:00:00Z