The objective of this research is to understand the signaling mechanisms that cells use to migrate and that axon growth cones use to home to their synaptic targets. To elucidate these mechanisms and their underlying molecular components, we are identifying and characterizing axon guidance and cell migration mutants in a model animal, C. elegans. We and others have shown that C. elegans uses many of the same molecular mechanisms (e.g., UNC-6/netrin signaling) used to guide cell and axon migrations in the mammalian spinal cord and C.N.S. These mutants allow us to identify novel components of migration mechanisms used by cells and axons, and fit them into a molecular pathway whose functional output we can monitor in vivo. We have discovered a novel TGF-beta signaling pathways that guides cell and axon migrations in C. elegans and have identified additional mutants that should allow us to reveal how this pathway and the UNC-6/netrin signaling pathway function during the development of the nervous system as well as other organ systems. An understanding of these pathways should help identify homologous pathways in humans, and provide potential targets for therapeutic interventions aimed at regenerating neurons or preventing spread of metastatic cancer cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS041397-03
Application #
6659834
Study Section
Special Emphasis Panel (ZRG1-MDCN-7 (01))
Program Officer
Mamounas, Laura
Project Start
2001-07-15
Project End
2006-06-30
Budget Start
2003-07-01
Budget End
2004-06-30
Support Year
3
Fiscal Year
2003
Total Cost
$263,211
Indirect Cost
Name
MT Sinai Hosp-Samuel Lunenfeld Research Institute
Department
Type
DUNS #
208808949
City
Toronto
State
ON
Country
Canada
Zip Code
M5 3-L9
Ikegami, Richard; Simokat, Kristin; Zheng, Hong et al. (2012) Semaphorin and Eph receptor signaling guide a series of cell movements for ventral enclosure in C. elegans. Curr Biol 22:1-11
MacNeil, Lesley T; Hardy, W Rod; Pawson, Tony et al. (2009) UNC-129 regulates the balance between UNC-40 dependent and independent UNC-5 signaling pathways. Nat Neurosci 12:150-5
Kawano, Takehiro; Zheng, Hong; Merz, David C et al. (2009) C. elegans mig-6 encodes papilin isoforms that affect distinct aspects of DTC migration, and interacts genetically with mig-17 and collagen IV. Development 136:1433-42
Fujisawa, Kazuko; Wrana, Jeffrey L; Culotti, Joseph G (2007) The slit receptor EVA-1 coactivates a SAX-3/Robo mediated guidance signal in C. elegans. Science 317:1934-8
Levy-Strumpf, Naomi; Culotti, Joseph G (2007) VAB-8, UNC-73 and MIG-2 regulate axon polarity and cell migration functions of UNC-40 in C. elegans. Nat Neurosci 10:161-8
Steven, Robert; Zhang, Lijia; Culotti, Joseph et al. (2005) The UNC-73/Trio RhoGEF-2 domain is required in separate isoforms for the regulation of pharynx pumping and normal neurotransmission in C. elegans. Genes Dev 19:2016-29
Dalpe, Gratien; Brown, Louise; Culotti, Joseph G (2005) Vulva morphogenesis involves attraction of plexin 1-expressing primordial vulva cells to semaphorin 1a sequentially expressed at the vulva midline. Development 132:1387-400
Dalpe, Gratien; Zhang, Lijia W; Zheng, Hong et al. (2004) Conversion of cell movement responses to Semaphorin-1 and Plexin-1 from attraction to repulsion by lowered levels of specific RAC GTPases in C. elegans. Development 131:2073-88
Sanyal, Suparna; Wintle, Richard F; Kindt, Katie S et al. (2004) Dopamine modulates the plasticity of mechanosensory responses in Caenorhabditis elegans. EMBO J 23:473-82
Ikegami, Richard; Zheng, Hong; Ong, Siew-Hwa et al. (2004) Integration of semaphorin-2A/MAB-20, ephrin-4, and UNC-129 TGF-beta signaling pathways regulates sorting of distinct sensory rays in C. elegans. Dev Cell 6:383-95

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