Heterochronic Protein Expression Patterns in the Developing Embryonic Chick Cerebellum
Version of Record online: 3 AUG 2012
Copyright © 2012 Wiley Periodicals, Inc.
The Anatomical Record
Volume 295, Issue 10, pages 1669–1682, October 2012
How to Cite
Gilbert, E., Lim, Y., Vickaryous, M. and Armstrong, C. (2012), Heterochronic Protein Expression Patterns in the Developing Embryonic Chick Cerebellum. Anat Rec, 295: 1669–1682. doi: 10.1002/ar.22544
- Issue online: 12 SEP 2012
- Version of Record online: 3 AUG 2012
- Manuscript Accepted: 11 JUL 2012
- Manuscript Revised: 12 JUN 2012
- Manuscript Received: 7 FEB 2012
- NSERC Discovery. Grant Number: 400101 (CLA)
- zebrin II; calretinin;
- neurodevelopmental heterochrony
The advantages of the embryonic chick as a model for studying neural development range from the relatively low cost of fertilized eggs to the rapid rate of development. We investigated in ovo cerebellar development in the chick, which has a nearly identical embryonic period as the mouse (19–22 days). We focused on three antigens: Calbindin (CB), Zebrin II (ZII), and Calretinin (CR), and our results demonstrate asynchronous expression patterns during cerebellar development. Presumptive CB+ Purkinje cells are first observed at embryonic day (E)10 in clusters in posterior cerebellum. At E12, corresponding with global expression of CB across the cerebellum, Purkinje cells began to express ZII. By E14–E16, Purkinje cells disperse into a monolayer and develop a pattern of alternating immunopositive and immunonegative ZII stripes. CR is initially expressed by clusters of presumptive Purkinje cells in the nodular zone at E8. However, this expression is transient and at later stages, CR is largely confined to the granule and molecular layers. Before hatch (E18–E20), Purkinje cells adopt a morphologically mature phenotype with complex dendritic arborizations. Comparing this data to that seen in mice, we found that the sequence of Purkinje cell formation, protein expression, and development is similar in both species, but these events consistently begin ∼5–7 days earlier in the precocial chick cerebellum, suggesting an important role for heterochrony in neurodevelopment. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.