Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published October 26, 2005 | public
Journal Article

Time-Lapse Analysis Reveals a Series of Events by Which Cranial Neural Crest Cells Reroute around Physical Barriers

Abstract

Segmentation is crucial to the development of the vertebrate body plan. Underlying segmentation in the head is further revealed when cranial neural crest cells emerge from even numbered rhombomeres in the hindbrain to form three stereotypical migratory streams that lead to the peripheral branchial arches. To test the role of intrinsic versus extrinsic cues in influencing an individual cell's trajectory, we implanted physical barriers in the chick mesoderm, distal to emerging neural crest cell stream fronts. We analyzed the spatio-temporal dynamics as individual neural crest cells encountered and responded to the barriers, using time-lapse confocal imaging. We find the majority of neural crest cells reach the branchial arch destinations following a repeatable series of events by which the cells overcome the barriers. Even though the lead cells become temporarily blocked by a barrier, cells that follow from behind find a novel pathway around a barrier and become de novo leaders of a new stream. Surprisingly, quantitative analyses of cell trajectories show that cells that encounter an r3 barrier migrate significantly faster but less directly than cells that encounter an r4 barrier, which migrate normally. Interestingly, we also find that cells temporarily blocked by the barrier migrate slightly faster and change direction more often. In addition, we show that cells can be forced to migrate into normally repulsive territory. These results suggest that cranial neural crest cell trajectories are not intrinsically determined, that cells can respond to minor alterations in the environment and re-target a peripheral destination, and that both intrinsic and extrinsic cues are important in patterning.

Additional Information

© 2005 S. Karger AG, Basel. Published online: October 25, 2005. The authors would like to thank R. Krumlauf for the generous gift of the pca-GFP construct; M. Basch and M. Bronner-Fraser for the generous gift of tantalum foil. P.M.K. would like to thank the Burroughs Wellcome funded Computational Molecular Biology Program at Caltech for their generous support during this work. C.C.L. and S.E.F. are supported in part by the Beckman Institute and the NIH. P.M.K. and C.C.L. contributed equally to this work.

Additional details

Created:
August 19, 2023
Modified:
October 17, 2023