PT - JOURNAL ARTICLE AU - Karam, Sana D. AU - Burrows, Robert C. AU - Logan, Cairine AU - Koblar, Simon AU - Pasquale, Elena B. AU - Bothwell, Mark TI - Eph Receptors and Ephrins in the Developing Chick Cerebellum: Relationship to Sagittal Patterning and Granule Cell Migration AID - 10.1523/JNEUROSCI.20-17-06488.2000 DP - 2000 Sep 01 TA - The Journal of Neuroscience PG - 6488--6500 VI - 20 IP - 17 4099 - http://www.jneurosci.org/content/20/17/6488.short 4100 - http://www.jneurosci.org/content/20/17/6488.full SO - J. Neurosci.2000 Sep 01; 20 AB - Spatiotemporal expression patterns of six members of the Eph gene family (EphA4, EphA3, EphB2, ephrin-B1, ephrin-A2, and ephrin-A5) were characterized immunocytochemically at various stages of chick cerebellar development. EphA4 expression is observed in the cerebellar anlage as early as embryonic day 5 (E5) and continues in the posthatch cerebellum. During the early period of cerebellar development (E3–E8), complementarity is observed between EphA4 and ephrin-A5 expression within the cerebellar-isthmal region. By E8, differential expression of EphA4 in parasagittal Purkinje cell bands is evident, and the expression remains banded in the posthatch cerebellum. Banded expression of the ephrin-A5 ligand complements EphA4 expression during the middle period (E9–E15). During this period, ephrin-A2 and EphA3 are coexpressed in a banded pattern and with variable correlation to EphA4. Variability in the banding expression is observed for EphA4, EphA3, ephrin-A5, and ephrin-A2 across different lobes, and graded complementarity in the expression pattern of EphA3 and ephrin-A5 is observed in the external granular layer between the posterior and anterior lobes. Analysis of Purkinje cell birth date in correlation with Eph–ephrin expression during the middle period reveals that early-born cells express EphA4, whereas late-born cells express ephrin-A5. Finally, EphA4 expression domains are respected by migrating granule cell ribbons, which express both ephrin-B1 and EphB2. These expression patterns suggest multiple roles for the Eph–ephrin system in cerebellar development, including demarcation/enforcement of boundaries of the cerebellar anlage, formation/maintenance of Purkinje cell compartments, and restriction of the early phase of granule cell migration to ribbons.