| Project/Area Number |
11680733
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nerve anatomy/Neuropathology
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| Research Institution | University of Tsukuba |
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Principal Investigator |
SHIGA Takeshi University of Tsukuba, Inst. Basic Med. Sci., Assoc. Prof., 基礎医学系, 助教授 (50178860)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1999: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | axonin-l / SC2 / neuropilin-1 / dorsal root ganglion / chemorepulsion / axon guidance / collagen gel culture / dermamyotome / notochord |
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| Research Abstract |
Initial trajectories of dorsal root ganglion (DRG) axons are shaped by chemorepulsion of surrounding tissues. Previous studies have suggested that the developing notochord, dermamyotome and ventral spinal cord secretes diffusible axon guidance molecules that repel dorsal root ganglion (DRG) neurites (Keynes et al. (1997) Neuron 18, 889-897; Nakamoto and Shiga (1998) Developmental Biology 202, 304-314). Neither chemorepellents nor their receptors on DRG neurites are, however, known. Here we investigated whether cell adhesion molecules of the immunoglobulin/fibronectin type III sub family (IgFnIII CAMs) and neuropilin-1 both of which are localized on DRG neurites are required for mediating the chemorepulsion from these tissues. We cocultured DRGs with notochord, dermamyotome or ventral spinal cord explants from either chick or mouse embryos in a collagen gel. We found that an antibody against axonin-l/SC2 diminished the effects of the chemorepulsive activity from the notochord, whereas antibodies against N-CAM, Ng-CAM and Nr-CAM had no effect. We also found that DRGs from neuropilm-1-deficient mice lost completely the responsiveness for the dermamyotome-derived chemorepulsion, whereas those diminished significantly but incompletely the responsiveness for the notochord-derived chemorepulsion. No changes were observed for the responsiveness for the ventral spinal cord-derived chemorepulsion. Thus, the present study revealed the differential chemorepulsion systems are involved in mediating the chemorepulsion for DRG axons.
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