- page settings
- showhide sidebar
- showhide empty fields
- layout
- (too narrow)
- open all
- close all
- Page Content
- Overview
- External Links
- History
- Referenced
- Tools
- Tree Display
- My WormBase
- My Favorites
- My Library
- Recent Activity
- Comments (0)
history logging is off
Tree Display
My Favorites
My Library
Comments on Shah, P.K. et al. (2017) International Worm Meeting "PCP and SAX-3/Robo pathways cooperate to regulate convergent extension-based nerve cord assembly." (0)
Overview
Shah, P.K., Tanner, M., Kovacevic, I., Rankin, A., Bao, Z., & Colavita, A. (2017). PCP and SAX-3/Robo pathways cooperate to regulate convergent extension-based nerve cord assembly presented in International Worm Meeting. Unpublished information; cite only with author permission.
At hatching DD, DA and DB motor neurons are stereotypically ordered relative to each other and distributed as a single track along the anterior-posterior (AP) axis. During embryogenesis, these neurons arise from left and right lineages, move towards the midline and intercalate to assemble the presumptive VNC. This morphogenetic process, in particular how neurons intercalate to assemble the VNC, has not been well characterized. We performed 3D fluorescence time-lapse imaging to show that intercalation of VNC neurons into a linear structure that extends the length of the AP axis involves a rosette-mediated convergent extension (CE) process. The planar cell polarity (PCP) pathway plays a highly conserved role in CE-based movements. Using the 6 DD neurons which are evenly spaced along the AP axis and therefore a convenient marker of VNC assembly, we found that mutations in the core PCP components vang-1/Vang Gogh and prkl-1/Prickle caused DD neurons to be anteriorly displaced in newly hatched worms. In the embryo, these mutants displayed defects in cell neighbor exchange and rosette resolution. Interestingly, we found that mutations in sax-3/Robo, a gene better known for roles in axon guidance, displayed similar defects in DD positioning and embryonic cell-neighbor exchanges. VANG-1 and SAX-3 are localized to contracting edges and rosette foci. Exploring further, we found that PCP/sax-3 double mutants display a significantly shortened, anteriorly displaced distribution of VNC neurons compared to single mutants. This simultaneous loss of both PCP and sax-3/Robo correlated with a severe disruption of CE in the embryo suggesting that these pathways act in parallel during VNC assembly. Our results indicate that rosette-based convergent extension is conserved in central nerve cord assembly and reveals a novel role for sax-3/Robo in this process.
Affiliations:
- Developmental Biology Program, Sloan Kettering Institute, New York, NY
- co-senior authors
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON
- equal contribution
- Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, ON