Temporal identity transition in the avian cerebellar rhombic lip

TY - JOUR

T1 - Temporal identity transition in the avian cerebellar rhombic lip

AU - Wilson, L J

AU - Wingate, R J T

PY - 2006/9/15

Y1 - 2006/9/15

N2 - The rhombic lip is a discrete strip of neuroepithelium bordering the rootplate of the fourth ventricle, which gives rise to a defined sequence of migratory neuronal derivatives. In rhombomere I of the chick, early born cells give rise to post-mitotic hindbrain nuclei, while later derivatives comprise of cerebellar granule cell precursors, a unique proliferative, migratory precursor population that forms the external granule cell layer. We have examined the temporal specification of these two populations using a heterochronic grafting strategy, in ovo. When transplanted into younger neural tube, rhombic lip cells maintain their characteristic molecular markers and migrate into the hindbrain. Granule cell precursor derivatives of late grafts are, in addition, able to exploit neural crest streams to populate the branchial arches. Within the neural tube, derivatives of early and late rhombic lip progenitors display patterns of migration and process extension, characterised by specific trajectories and targets, which are consistent with their temporal origin. However, the normal temporal progression of cell production is disrupted in grafted progenitors: transplanted early rhombic lip fails to subsequently produce granule cell precursors. This indicates that, while the behaviour of derivatives is intrinsically specified at the rhombic lip, the orderly temporal transition in cell type production is dependent on extrinsic cues present only in the later embryo. (c) 2006 Elsevier Inc. All rights reserved

AB - The rhombic lip is a discrete strip of neuroepithelium bordering the rootplate of the fourth ventricle, which gives rise to a defined sequence of migratory neuronal derivatives. In rhombomere I of the chick, early born cells give rise to post-mitotic hindbrain nuclei, while later derivatives comprise of cerebellar granule cell precursors, a unique proliferative, migratory precursor population that forms the external granule cell layer. We have examined the temporal specification of these two populations using a heterochronic grafting strategy, in ovo. When transplanted into younger neural tube, rhombic lip cells maintain their characteristic molecular markers and migrate into the hindbrain. Granule cell precursor derivatives of late grafts are, in addition, able to exploit neural crest streams to populate the branchial arches. Within the neural tube, derivatives of early and late rhombic lip progenitors display patterns of migration and process extension, characterised by specific trajectories and targets, which are consistent with their temporal origin. However, the normal temporal progression of cell production is disrupted in grafted progenitors: transplanted early rhombic lip fails to subsequently produce granule cell precursors. This indicates that, while the behaviour of derivatives is intrinsically specified at the rhombic lip, the orderly temporal transition in cell type production is dependent on extrinsic cues present only in the later embryo. (c) 2006 Elsevier Inc. All rights reserved

U2 - 10.1016/j.ydbio.2006.05.028

DO - 10.1016/j.ydbio.2006.05.028

M3 - Article

SN - 1095-564X

VL - 297

SP - 508

EP - 521

JO - Developmental Biology

JF - Developmental Biology

IS - 2

ER -